tests/x509/test_x509.py

# -*- coding: utf-8 -*-
# This file is dual licensed under the terms of the Apache License, Version
# 2.0, and the BSD License. See the LICENSE file in the root of this repository
# for complete details.

from __future__ import absolute_import, division, print_function

import binascii
import collections
import copy
import datetime
import ipaddress
import os

import pytest

import pytz

import six

from cryptography import utils, x509
from cryptography.exceptions import UnsupportedAlgorithm
from cryptography.hazmat._der import (
    BIT_STRING,
    CONSTRUCTED,
    CONTEXT_SPECIFIC,
    DERReader,
    GENERALIZED_TIME,
    INTEGER,
    OBJECT_IDENTIFIER,
    PRINTABLE_STRING,
    SEQUENCE,
    SET,
    UTC_TIME,
)
from cryptography.hazmat.backends.interfaces import (
    DSABackend,
    EllipticCurveBackend,
    RSABackend,
    X509Backend,
)
from cryptography.hazmat.primitives import hashes, serialization
from cryptography.hazmat.primitives.asymmetric import (
    dh,
    dsa,
    ec,
    ed25519,
    ed448,
    padding,
    rsa,
)
from cryptography.hazmat.primitives.asymmetric.utils import (
    decode_dss_signature,
)
from cryptography.utils import int_from_bytes
from cryptography.x509.name import _ASN1Type
from cryptography.x509.oid import (
    AuthorityInformationAccessOID,
    ExtendedKeyUsageOID,
    ExtensionOID,
    NameOID,
    SignatureAlgorithmOID,
    SubjectInformationAccessOID,
)

from ..hazmat.primitives.fixtures_dsa import DSA_KEY_2048
from ..hazmat.primitives.fixtures_ec import EC_KEY_SECP256R1
from ..hazmat.primitives.fixtures_rsa import RSA_KEY_2048, RSA_KEY_512
from ..hazmat.primitives.test_ec import _skip_curve_unsupported
from ..utils import load_nist_vectors, load_vectors_from_file


@utils.register_interface(x509.ExtensionType)
class DummyExtension(object):
    oid = x509.ObjectIdentifier("1.2.3.4")


@utils.register_interface(x509.GeneralName)
class FakeGeneralName(object):
    def __init__(self, value):
        self._value = value

    value = utils.read_only_property("_value")


def _load_cert(filename, loader, backend):
    cert = load_vectors_from_file(
        filename=filename,
        loader=lambda pemfile: loader(pemfile.read(), backend),
        mode="rb",
    )
    return cert


ParsedCertificate = collections.namedtuple(
    "ParsedCertificate",
    ["not_before_tag", "not_after_tag", "issuer", "subject"],
)


def _parse_cert(der):
    # See the Certificate structured, defined in RFC 5280.
    with DERReader(der).read_single_element(SEQUENCE) as cert:
        tbs_cert = cert.read_element(SEQUENCE)
        # Skip outer signature algorithm
        _ = cert.read_element(SEQUENCE)
        # Skip signature
        _ = cert.read_element(BIT_STRING)

    with tbs_cert:
        # Skip version
        _ = tbs_cert.read_optional_element(CONTEXT_SPECIFIC | CONSTRUCTED | 0)
        # Skip serialNumber
        _ = tbs_cert.read_element(INTEGER)
        # Skip inner signature algorithm
        _ = tbs_cert.read_element(SEQUENCE)
        issuer = tbs_cert.read_element(SEQUENCE)
        validity = tbs_cert.read_element(SEQUENCE)
        subject = tbs_cert.read_element(SEQUENCE)
        # Skip subjectPublicKeyInfo
        _ = tbs_cert.read_element(SEQUENCE)
        # Skip issuerUniqueID
        _ = tbs_cert.read_optional_element(CONTEXT_SPECIFIC | CONSTRUCTED | 1)
        # Skip subjectUniqueID
        _ = tbs_cert.read_optional_element(CONTEXT_SPECIFIC | CONSTRUCTED | 2)
        # Skip extensions
        _ = tbs_cert.read_optional_element(CONTEXT_SPECIFIC | CONSTRUCTED | 3)

    with validity:
        not_before_tag, _ = validity.read_any_element()
        not_after_tag, _ = validity.read_any_element()

    return ParsedCertificate(
        not_before_tag=not_before_tag,
        not_after_tag=not_after_tag,
        issuer=issuer,
        subject=subject,
    )


@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestCertificateRevocationList(object):
    def test_load_pem_crl(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        assert isinstance(crl, x509.CertificateRevocationList)
        fingerprint = binascii.hexlify(crl.fingerprint(hashes.SHA1()))
        assert fingerprint == b"3234b0cb4c0cedf6423724b736729dcfc9e441ef"
        assert isinstance(crl.signature_hash_algorithm, hashes.SHA256)
        assert (
            crl.signature_algorithm_oid
            == SignatureAlgorithmOID.RSA_WITH_SHA256
        )

    def test_load_der_crl(self, backend):
        crl = _load_cert(
            os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
            x509.load_der_x509_crl,
            backend,
        )

        assert isinstance(crl, x509.CertificateRevocationList)
        fingerprint = binascii.hexlify(crl.fingerprint(hashes.SHA1()))
        assert fingerprint == b"dd3db63c50f4c4a13e090f14053227cb1011a5ad"
        assert isinstance(crl.signature_hash_algorithm, hashes.SHA256)

    def test_invalid_pem(self, backend):
        with pytest.raises(ValueError):
            x509.load_pem_x509_crl(b"notacrl", backend)

    def test_invalid_der(self, backend):
        with pytest.raises(ValueError):
            x509.load_der_x509_crl(b"notacrl", backend)

    def test_unknown_signature_algorithm(self, backend):
        crl = _load_cert(
            os.path.join(
                "x509", "custom", "crl_md2_unknown_crit_entry_ext.pem"
            ),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(UnsupportedAlgorithm):
            crl.signature_hash_algorithm()

    def test_issuer(self, backend):
        crl = _load_cert(
            os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
            x509.load_der_x509_crl,
            backend,
        )

        assert isinstance(crl.issuer, x509.Name)
        assert list(crl.issuer) == [
            x509.NameAttribute(x509.OID_COUNTRY_NAME, u"US"),
            x509.NameAttribute(
                x509.OID_ORGANIZATION_NAME, u"Test Certificates 2011"
            ),
            x509.NameAttribute(x509.OID_COMMON_NAME, u"Good CA"),
        ]
        assert crl.issuer.get_attributes_for_oid(x509.OID_COMMON_NAME) == [
            x509.NameAttribute(x509.OID_COMMON_NAME, u"Good CA")
        ]

    def test_equality(self, backend):
        crl1 = _load_cert(
            os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
            x509.load_der_x509_crl,
            backend,
        )

        crl2 = _load_cert(
            os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
            x509.load_der_x509_crl,
            backend,
        )

        crl3 = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        assert crl1 == crl2
        assert crl1 != crl3
        assert crl1 != object()

    def test_update_dates(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        assert isinstance(crl.next_update, datetime.datetime)
        assert isinstance(crl.last_update, datetime.datetime)

        assert crl.next_update.isoformat() == "2016-01-01T00:00:00"
        assert crl.last_update.isoformat() == "2015-01-01T00:00:00"

    def test_revoked_cert_retrieval(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        for r in crl:
            assert isinstance(r, x509.RevokedCertificate)

        # Check that len() works for CRLs.
        assert len(crl) == 12

    def test_get_revoked_certificate_by_serial_number(self, backend):
        crl = _load_cert(
            os.path.join(
                "x509", "PKITS_data", "crls", "LongSerialNumberCACRL.crl"
            ),
            x509.load_der_x509_crl,
            backend,
        )
        serial_number = 725064303890588110203033396814564464046290047507
        revoked = crl.get_revoked_certificate_by_serial_number(serial_number)
        assert revoked.serial_number == serial_number
        assert crl.get_revoked_certificate_by_serial_number(500) is None

    def test_revoked_cert_retrieval_retain_only_revoked(self, backend):
        """
        This test attempts to trigger the crash condition described in
        https://github.com/pyca/cryptography/issues/2557
        PyPy does gc at its own pace, so it will only be reliable on CPython.
        """
        revoked = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )[11]
        assert revoked.revocation_date == datetime.datetime(2015, 1, 1, 0, 0)
        assert revoked.serial_number == 11

    def test_extensions(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_ian_aia_aki.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        crl_number = crl.extensions.get_extension_for_oid(
            ExtensionOID.CRL_NUMBER
        )
        aki = crl.extensions.get_extension_for_class(
            x509.AuthorityKeyIdentifier
        )
        aia = crl.extensions.get_extension_for_class(
            x509.AuthorityInformationAccess
        )
        ian = crl.extensions.get_extension_for_class(
            x509.IssuerAlternativeName
        )
        assert crl_number.value == x509.CRLNumber(1)
        assert crl_number.critical is False
        assert aki.value == x509.AuthorityKeyIdentifier(
            key_identifier=(b"yu\xbb\x84:\xcb,\xdez\t\xbe1\x1bC\xbc\x1c*MSX"),
            authority_cert_issuer=None,
            authority_cert_serial_number=None,
        )
        assert aia.value == x509.AuthorityInformationAccess(
            [
                x509.AccessDescription(
                    AuthorityInformationAccessOID.CA_ISSUERS,
                    x509.DNSName(u"cryptography.io"),
                )
            ]
        )
        assert ian.value == x509.IssuerAlternativeName(
            [x509.UniformResourceIdentifier(u"https://cryptography.io")]
        )

    def test_delta_crl_indicator(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_delta_crl_indicator.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        dci = crl.extensions.get_extension_for_oid(
            ExtensionOID.DELTA_CRL_INDICATOR
        )
        assert dci.value == x509.DeltaCRLIndicator(12345678901234567890)
        assert dci.critical is True

    def test_signature(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        assert crl.signature == binascii.unhexlify(
            b"536a5a0794f68267361e7bc2f19167a3e667a2ab141535616855d8deb2ba1af"
            b"9fd4546b1fe76b454eb436af7b28229fedff4634dfc9dd92254266219ae0ea8"
            b"75d9ff972e9a2da23d5945f073da18c50a4265bfed9ca16586347800ef49dd1"
            b"6856d7265f4f3c498a57f04dc04404e2bd2e2ada1f5697057aacef779a18371"
            b"c621edc9a5c2b8ec1716e8fa22feeb7fcec0ce9156c8d344aa6ae8d1a5d99d0"
            b"9386df36307df3b63c83908f4a61a0ff604c1e292ad63b349d1082ddd7ae1b7"
            b"c178bba995523ec6999310c54da5706549797bfb1230f5593ba7b4353dade4f"
            b"d2be13a57580a6eb20b5c4083f000abac3bf32cd8b75f23e4c8f4b3a79e1e2d"
            b"58a472b0"
        )

    def test_tbs_certlist_bytes(self, backend):
        crl = _load_cert(
            os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
            x509.load_der_x509_crl,
            backend,
        )

        ca_cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )

        ca_cert.public_key().verify(
            crl.signature,
            crl.tbs_certlist_bytes,
            padding.PKCS1v15(),
            crl.signature_hash_algorithm,
        )

    def test_public_bytes_pem(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_empty.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        # Encode it to PEM and load it back.
        crl = x509.load_pem_x509_crl(
            crl.public_bytes(
                encoding=serialization.Encoding.PEM,
            ),
            backend,
        )

        assert len(crl) == 0
        assert crl.last_update == datetime.datetime(2015, 12, 20, 23, 44, 47)
        assert crl.next_update == datetime.datetime(2015, 12, 28, 0, 44, 47)

    def test_public_bytes_der(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        # Encode it to DER and load it back.
        crl = x509.load_der_x509_crl(
            crl.public_bytes(
                encoding=serialization.Encoding.DER,
            ),
            backend,
        )

        assert len(crl) == 12
        assert crl.last_update == datetime.datetime(2015, 1, 1, 0, 0, 0)
        assert crl.next_update == datetime.datetime(2016, 1, 1, 0, 0, 0)

    @pytest.mark.parametrize(
        ("cert_path", "loader_func", "encoding"),
        [
            (
                os.path.join("x509", "custom", "crl_all_reasons.pem"),
                x509.load_pem_x509_crl,
                serialization.Encoding.PEM,
            ),
            (
                os.path.join("x509", "PKITS_data", "crls", "GoodCACRL.crl"),
                x509.load_der_x509_crl,
                serialization.Encoding.DER,
            ),
        ],
    )
    def test_public_bytes_match(
        self, cert_path, loader_func, encoding, backend
    ):
        crl_bytes = load_vectors_from_file(
            cert_path, lambda pemfile: pemfile.read(), mode="rb"
        )
        crl = loader_func(crl_bytes, backend)
        serialized = crl.public_bytes(encoding)
        assert serialized == crl_bytes

    def test_public_bytes_invalid_encoding(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_empty.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(TypeError):
            crl.public_bytes("NotAnEncoding")

    def test_verify_bad(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "invalid_signature.pem"),
            x509.load_pem_x509_crl,
            backend,
        )
        crt = _load_cert(
            os.path.join("x509", "custom", "invalid_signature.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )

        assert not crl.is_signature_valid(crt.public_key())

    def test_verify_good(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "valid_signature.pem"),
            x509.load_pem_x509_crl,
            backend,
        )
        crt = _load_cert(
            os.path.join("x509", "custom", "valid_signature.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )

        assert crl.is_signature_valid(crt.public_key())

    def test_verify_argument_must_be_a_public_key(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "valid_signature.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(TypeError):
            crl.is_signature_valid("not a public key")

        with pytest.raises(TypeError):
            crl.is_signature_valid(object)


@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestRevokedCertificate(object):
    def test_revoked_basics(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        for i, rev in enumerate(crl):
            assert isinstance(rev, x509.RevokedCertificate)
            assert isinstance(rev.serial_number, int)
            assert isinstance(rev.revocation_date, datetime.datetime)
            assert isinstance(rev.extensions, x509.Extensions)

            assert rev.serial_number == i
            assert rev.revocation_date.isoformat() == "2015-01-01T00:00:00"

    def test_revoked_extensions(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        exp_issuer = [
            x509.DirectoryName(
                x509.Name(
                    [
                        x509.NameAttribute(x509.OID_COUNTRY_NAME, u"US"),
                        x509.NameAttribute(
                            x509.OID_COMMON_NAME, u"cryptography.io"
                        ),
                    ]
                )
            )
        ]

        # First revoked cert doesn't have extensions, test if it is handled
        # correctly.
        rev0 = crl[0]
        # It should return an empty Extensions object.
        assert isinstance(rev0.extensions, x509.Extensions)
        assert len(rev0.extensions) == 0
        with pytest.raises(x509.ExtensionNotFound):
            rev0.extensions.get_extension_for_oid(x509.OID_CRL_REASON)
        with pytest.raises(x509.ExtensionNotFound):
            rev0.extensions.get_extension_for_oid(x509.OID_CERTIFICATE_ISSUER)
        with pytest.raises(x509.ExtensionNotFound):
            rev0.extensions.get_extension_for_oid(x509.OID_INVALIDITY_DATE)

        # Test manual retrieval of extension values.
        rev1 = crl[1]
        assert isinstance(rev1.extensions, x509.Extensions)

        reason = rev1.extensions.get_extension_for_class(x509.CRLReason).value
        assert reason == x509.CRLReason(x509.ReasonFlags.unspecified)

        issuer = rev1.extensions.get_extension_for_class(
            x509.CertificateIssuer
        ).value
        assert issuer == x509.CertificateIssuer(exp_issuer)

        date = rev1.extensions.get_extension_for_class(
            x509.InvalidityDate
        ).value
        assert date == x509.InvalidityDate(datetime.datetime(2015, 1, 1, 0, 0))

        # Check if all reason flags can be found in the CRL.
        flags = set(x509.ReasonFlags)
        for rev in crl:
            try:
                r = rev.extensions.get_extension_for_class(x509.CRLReason)
            except x509.ExtensionNotFound:
                # Not all revoked certs have a reason extension.
                pass
            else:
                flags.discard(r.value.reason)

        assert len(flags) == 0

    def test_no_revoked_certs(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_empty.pem"),
            x509.load_pem_x509_crl,
            backend,
        )
        assert len(crl) == 0

    def test_duplicate_entry_ext(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_dup_entry_ext.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(x509.DuplicateExtension):
            crl[0].extensions

    def test_unsupported_crit_entry_ext(self, backend):
        crl = _load_cert(
            os.path.join(
                "x509", "custom", "crl_md2_unknown_crit_entry_ext.pem"
            ),
            x509.load_pem_x509_crl,
            backend,
        )

        ext = crl[0].extensions.get_extension_for_oid(
            x509.ObjectIdentifier("1.2.3.4")
        )
        assert ext.value.value == b"\n\x01\x00"

    def test_unsupported_reason(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_unsupported_reason.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(ValueError):
            crl[0].extensions

    def test_invalid_cert_issuer_ext(self, backend):
        crl = _load_cert(
            os.path.join(
                "x509", "custom", "crl_inval_cert_issuer_entry_ext.pem"
            ),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(ValueError):
            crl[0].extensions

    def test_indexing(self, backend):
        crl = _load_cert(
            os.path.join("x509", "custom", "crl_all_reasons.pem"),
            x509.load_pem_x509_crl,
            backend,
        )

        with pytest.raises(IndexError):
            crl[-13]
        with pytest.raises(IndexError):
            crl[12]

        assert crl[-1].serial_number == crl[11].serial_number
        assert len(crl[2:4]) == 2
        assert crl[2:4][0].serial_number == crl[2].serial_number
        assert crl[2:4][1].serial_number == crl[3].serial_number

    def test_get_revoked_certificate_doesnt_reorder(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        last_update = datetime.datetime(2002, 1, 1, 12, 1)
        next_update = datetime.datetime(2030, 1, 1, 12, 1)
        builder = (
            x509.CertificateRevocationListBuilder()
            .issuer_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.COMMON_NAME, u"cryptography.io CA"
                        )
                    ]
                )
            )
            .last_update(last_update)
            .next_update(next_update)
        )
        for i in [2, 500, 3, 49, 7, 1]:
            revoked_cert = (
                x509.RevokedCertificateBuilder()
                .serial_number(i)
                .revocation_date(datetime.datetime(2012, 1, 1, 1, 1))
                .build(backend)
            )
            builder = builder.add_revoked_certificate(revoked_cert)
        crl = builder.sign(private_key, hashes.SHA256(), backend)
        assert crl[0].serial_number == 2
        assert crl[2].serial_number == 3
        # make sure get_revoked_certificate_by_serial_number doesn't affect
        # ordering after being invoked
        crl.get_revoked_certificate_by_serial_number(500)
        assert crl[0].serial_number == 2
        assert crl[2].serial_number == 3


@pytest.mark.requires_backend_interface(interface=RSABackend)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestRSACertificate(object):
    def test_load_pem_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert isinstance(cert, x509.Certificate)
        assert cert.serial_number == 11559813051657483483
        fingerprint = binascii.hexlify(cert.fingerprint(hashes.SHA1()))
        assert fingerprint == b"2b619ed04bfc9c3b08eb677d272192286a0947a8"
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA1)
        assert (
            cert.signature_algorithm_oid == SignatureAlgorithmOID.RSA_WITH_SHA1
        )

    def test_negative_serial_number(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "negative_serial.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.serial_number == -18008675309

    def test_alternate_rsa_with_sha1_oid(self, backend):
        cert = _load_cert(
            os.path.join("x509", "alternate-rsa-sha1-oid.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA1)
        assert (
            cert.signature_algorithm_oid
            == SignatureAlgorithmOID._RSA_WITH_SHA1
        )

    def test_load_der_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )
        assert isinstance(cert, x509.Certificate)
        assert cert.serial_number == 2
        fingerprint = binascii.hexlify(cert.fingerprint(hashes.SHA1()))
        assert fingerprint == b"6f49779533d565e8b7c1062503eab41492c38e4d"
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA256)

    def test_signature(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.signature == binascii.unhexlify(
            b"8e0f72fcbebe4755abcaf76c8ce0bae17cde4db16291638e1b1ce04a93cdb4c"
            b"44a3486070986c5a880c14fdf8497e7d289b2630ccb21d24a3d1aa1b2d87482"
            b"07f3a1e16ccdf8daa8a7ea1a33d49774f513edf09270bd8e665b6300a10f003"
            b"66a59076905eb63cf10a81a0ca78a6ef3127f6cb2f6fb7f947fce22a30d8004"
            b"8c243ba2c1a54c425fe12310e8a737638f4920354d4cce25cbd9dea25e6a2fe"
            b"0d8579a5c8d929b9275be221975479f3f75075bcacf09526523b5fd67f7683f"
            b"3cda420fabb1e9e6fc26bc0649cf61bb051d6932fac37066bb16f55903dfe78"
            b"53dc5e505e2a10fbba4f9e93a0d3b53b7fa34b05d7ba6eef869bfc34b8e514f"
            b"d5419f75"
        )
        assert len(cert.signature) == cert.public_key().key_size // 8

    def test_tbs_certificate_bytes(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.tbs_certificate_bytes == binascii.unhexlify(
            b"308202d8a003020102020900a06cb4b955f7f4db300d06092a864886f70d010"
            b"10505003058310b3009060355040613024155311330110603550408130a536f"
            b"6d652d53746174653121301f060355040a1318496e7465726e6574205769646"
            b"769747320507479204c74643111300f0603550403130848656c6c6f20434130"
            b"1e170d3134313132363231343132305a170d3134313232363231343132305a3"
            b"058310b3009060355040613024155311330110603550408130a536f6d652d53"
            b"746174653121301f060355040a1318496e7465726e657420576964676974732"
            b"0507479204c74643111300f0603550403130848656c6c6f2043413082012230"
            b"0d06092a864886f70d01010105000382010f003082010a0282010100b03af70"
            b"2059e27f1e2284b56bbb26c039153bf81f295b73a49132990645ede4d2da0a9"
            b"13c42e7d38d3589a00d3940d194f6e6d877c2ef812da22a275e83d8be786467"
            b"48b4e7f23d10e873fd72f57a13dec732fc56ab138b1bb308399bb412cd73921"
            b"4ef714e1976e09603405e2556299a05522510ac4574db5e9cb2cf5f99e8f48c"
            b"1696ab3ea2d6d2ddab7d4e1b317188b76a572977f6ece0a4ad396f0150e7d8b"
            b"1a9986c0cb90527ec26ca56e2914c270d2a198b632fa8a2fda55079d3d39864"
            b"b6fb96ddbe331cacb3cb8783a8494ccccd886a3525078847ca01ca5f803e892"
            b"14403e8a4b5499539c0b86f7a0daa45b204a8e079d8a5b03db7ba1ba3d7011a"
            b"70203010001a381bc3081b9301d0603551d0e04160414d8e89dc777e4472656"
            b"f1864695a9f66b7b0400ae3081890603551d23048181307f8014d8e89dc777e"
            b"4472656f1864695a9f66b7b0400aea15ca45a3058310b300906035504061302"
            b"4155311330110603550408130a536f6d652d53746174653121301f060355040"
            b"a1318496e7465726e6574205769646769747320507479204c74643111300f06"
            b"03550403130848656c6c6f204341820900a06cb4b955f7f4db300c0603551d1"
            b"3040530030101ff"
        )
        cert.public_key().verify(
            cert.signature,
            cert.tbs_certificate_bytes,
            padding.PKCS1v15(),
            cert.signature_hash_algorithm,
        )

    def test_issuer(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "Validpre2000UTCnotBeforeDateTest3EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )
        issuer = cert.issuer
        assert isinstance(issuer, x509.Name)
        assert list(issuer) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(
                NameOID.ORGANIZATION_NAME, u"Test Certificates 2011"
            ),
            x509.NameAttribute(NameOID.COMMON_NAME, u"Good CA"),
        ]
        assert issuer.get_attributes_for_oid(NameOID.COMMON_NAME) == [
            x509.NameAttribute(NameOID.COMMON_NAME, u"Good CA")
        ]

    def test_all_issuer_name_types(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "all_supported_names.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        issuer = cert.issuer

        assert isinstance(issuer, x509.Name)
        assert list(issuer) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"CA"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Illinois"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Chicago"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"Zero, LLC"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"One, LLC"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"common name 0"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"common name 1"),
            x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, u"OU 0"),
            x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, u"OU 1"),
            x509.NameAttribute(NameOID.DN_QUALIFIER, u"dnQualifier0"),
            x509.NameAttribute(NameOID.DN_QUALIFIER, u"dnQualifier1"),
            x509.NameAttribute(NameOID.SERIAL_NUMBER, u"123"),
            x509.NameAttribute(NameOID.SERIAL_NUMBER, u"456"),
            x509.NameAttribute(NameOID.TITLE, u"Title 0"),
            x509.NameAttribute(NameOID.TITLE, u"Title 1"),
            x509.NameAttribute(NameOID.SURNAME, u"Surname 0"),
            x509.NameAttribute(NameOID.SURNAME, u"Surname 1"),
            x509.NameAttribute(NameOID.GIVEN_NAME, u"Given Name 0"),
            x509.NameAttribute(NameOID.GIVEN_NAME, u"Given Name 1"),
            x509.NameAttribute(NameOID.PSEUDONYM, u"Incognito 0"),
            x509.NameAttribute(NameOID.PSEUDONYM, u"Incognito 1"),
            x509.NameAttribute(NameOID.GENERATION_QUALIFIER, u"Last Gen"),
            x509.NameAttribute(NameOID.GENERATION_QUALIFIER, u"Next Gen"),
            x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"dc0"),
            x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"dc1"),
            x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"test0@test.local"),
            x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"test1@test.local"),
        ]

    def test_subject(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "Validpre2000UTCnotBeforeDateTest3EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )
        subject = cert.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(
                NameOID.ORGANIZATION_NAME, u"Test Certificates 2011"
            ),
            x509.NameAttribute(
                NameOID.COMMON_NAME,
                u"Valid pre2000 UTC notBefore Date EE Certificate Test3",
            ),
        ]
        assert subject.get_attributes_for_oid(NameOID.COMMON_NAME) == [
            x509.NameAttribute(
                NameOID.COMMON_NAME,
                u"Valid pre2000 UTC notBefore Date EE Certificate Test3",
            )
        ]

    def test_unicode_name(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "utf8_common_name.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.subject.get_attributes_for_oid(NameOID.COMMON_NAME) == [
            x509.NameAttribute(NameOID.COMMON_NAME, u"We heart UTF8!\u2122")
        ]
        assert cert.issuer.get_attributes_for_oid(NameOID.COMMON_NAME) == [
            x509.NameAttribute(NameOID.COMMON_NAME, u"We heart UTF8!\u2122")
        ]

    def test_non_ascii_dns_name(self, backend):
        cert = _load_cert(
            os.path.join("x509", "utf8-dnsname.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        san = cert.extensions.get_extension_for_class(
            x509.SubjectAlternativeName
        ).value

        names = san.get_values_for_type(x509.DNSName)

        assert names == [
            u"partner.biztositas.hu",
            u"biztositas.hu",
            u"*.biztositas.hu",
            u"biztos\xedt\xe1s.hu",
            u"*.biztos\xedt\xe1s.hu",
            u"xn--biztosts-fza2j.hu",
            u"*.xn--biztosts-fza2j.hu",
        ]

    def test_all_subject_name_types(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "all_supported_names.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        subject = cert.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"AU"),
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"DE"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"California"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"New York"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"San Francisco"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Ithaca"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"Org Zero, LLC"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"Org One, LLC"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"CN 0"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"CN 1"),
            x509.NameAttribute(
                NameOID.ORGANIZATIONAL_UNIT_NAME, u"Engineering 0"
            ),
            x509.NameAttribute(
                NameOID.ORGANIZATIONAL_UNIT_NAME, u"Engineering 1"
            ),
            x509.NameAttribute(NameOID.DN_QUALIFIER, u"qualified0"),
            x509.NameAttribute(NameOID.DN_QUALIFIER, u"qualified1"),
            x509.NameAttribute(NameOID.SERIAL_NUMBER, u"789"),
            x509.NameAttribute(NameOID.SERIAL_NUMBER, u"012"),
            x509.NameAttribute(NameOID.TITLE, u"Title IX"),
            x509.NameAttribute(NameOID.TITLE, u"Title X"),
            x509.NameAttribute(NameOID.SURNAME, u"Last 0"),
            x509.NameAttribute(NameOID.SURNAME, u"Last 1"),
            x509.NameAttribute(NameOID.GIVEN_NAME, u"First 0"),
            x509.NameAttribute(NameOID.GIVEN_NAME, u"First 1"),
            x509.NameAttribute(NameOID.PSEUDONYM, u"Guy Incognito 0"),
            x509.NameAttribute(NameOID.PSEUDONYM, u"Guy Incognito 1"),
            x509.NameAttribute(NameOID.GENERATION_QUALIFIER, u"32X"),
            x509.NameAttribute(NameOID.GENERATION_QUALIFIER, u"Dreamcast"),
            x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"dc2"),
            x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"dc3"),
            x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"test2@test.local"),
            x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"test3@test.local"),
        ]

    def test_load_good_ca_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )

        assert cert.not_valid_before == datetime.datetime(2010, 1, 1, 8, 30)
        assert cert.not_valid_after == datetime.datetime(2030, 12, 31, 8, 30)
        assert cert.serial_number == 2
        public_key = cert.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        assert cert.version is x509.Version.v3
        fingerprint = binascii.hexlify(cert.fingerprint(hashes.SHA1()))
        assert fingerprint == b"6f49779533d565e8b7c1062503eab41492c38e4d"

    def test_utc_pre_2000_not_before_cert(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "Validpre2000UTCnotBeforeDateTest3EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )

        assert cert.not_valid_before == datetime.datetime(1950, 1, 1, 12, 1)

    def test_pre_2000_utc_not_after_cert(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "Invalidpre2000UTCEEnotAfterDateTest7EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )

        assert cert.not_valid_after == datetime.datetime(1999, 1, 1, 12, 1)

    def test_post_2000_utc_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.not_valid_before == datetime.datetime(
            2014, 11, 26, 21, 41, 20
        )
        assert cert.not_valid_after == datetime.datetime(
            2014, 12, 26, 21, 41, 20
        )

    def test_generalized_time_not_before_cert(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "ValidGeneralizedTimenotBeforeDateTest4EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )
        assert cert.not_valid_before == datetime.datetime(2002, 1, 1, 12, 1)
        assert cert.not_valid_after == datetime.datetime(2030, 12, 31, 8, 30)
        assert cert.version is x509.Version.v3

    def test_generalized_time_not_after_cert(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "ValidGeneralizedTimenotAfterDateTest8EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )
        assert cert.not_valid_before == datetime.datetime(2010, 1, 1, 8, 30)
        assert cert.not_valid_after == datetime.datetime(2050, 1, 1, 12, 1)
        assert cert.version is x509.Version.v3

    def test_invalid_version_cert(self, backend):
        with pytest.raises(x509.InvalidVersion) as exc:
            _load_cert(
                os.path.join("x509", "custom", "invalid_version.pem"),
                x509.load_pem_x509_certificate,
                backend,
            )

        assert exc.value.parsed_version == 7

    def test_eq(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        cert2 = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert == cert2

    def test_ne(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        cert2 = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "ValidGeneralizedTimenotAfterDateTest8EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )
        assert cert != cert2
        assert cert != object()

    def test_hash(self, backend):
        cert1 = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        cert2 = _load_cert(
            os.path.join("x509", "custom", "post2000utctime.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        cert3 = _load_cert(
            os.path.join(
                "x509",
                "PKITS_data",
                "certs",
                "ValidGeneralizedTimenotAfterDateTest8EE.crt",
            ),
            x509.load_der_x509_certificate,
            backend,
        )

        assert hash(cert1) == hash(cert2)
        assert hash(cert1) != hash(cert3)

    def test_version_1_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "v1_cert.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.version is x509.Version.v1

    def test_invalid_pem(self, backend):
        with pytest.raises(ValueError):
            x509.load_pem_x509_certificate(b"notacert", backend)

    def test_invalid_der(self, backend):
        with pytest.raises(ValueError):
            x509.load_der_x509_certificate(b"notacert", backend)

    def test_unsupported_signature_hash_algorithm_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "verisign_md2_root.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        with pytest.raises(UnsupportedAlgorithm):
            cert.signature_hash_algorithm

    def test_public_bytes_pem(self, backend):
        # Load an existing certificate.
        cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )

        # Encode it to PEM and load it back.
        cert = x509.load_pem_x509_certificate(
            cert.public_bytes(
                encoding=serialization.Encoding.PEM,
            ),
            backend,
        )

        # We should recover what we had to start with.
        assert cert.not_valid_before == datetime.datetime(2010, 1, 1, 8, 30)
        assert cert.not_valid_after == datetime.datetime(2030, 12, 31, 8, 30)
        assert cert.serial_number == 2
        public_key = cert.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        assert cert.version is x509.Version.v3
        fingerprint = binascii.hexlify(cert.fingerprint(hashes.SHA1()))
        assert fingerprint == b"6f49779533d565e8b7c1062503eab41492c38e4d"

    def test_public_bytes_der(self, backend):
        # Load an existing certificate.
        cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )

        # Encode it to DER and load it back.
        cert = x509.load_der_x509_certificate(
            cert.public_bytes(
                encoding=serialization.Encoding.DER,
            ),
            backend,
        )

        # We should recover what we had to start with.
        assert cert.not_valid_before == datetime.datetime(2010, 1, 1, 8, 30)
        assert cert.not_valid_after == datetime.datetime(2030, 12, 31, 8, 30)
        assert cert.serial_number == 2
        public_key = cert.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        assert cert.version is x509.Version.v3
        fingerprint = binascii.hexlify(cert.fingerprint(hashes.SHA1()))
        assert fingerprint == b"6f49779533d565e8b7c1062503eab41492c38e4d"

    def test_public_bytes_invalid_encoding(self, backend):
        cert = _load_cert(
            os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
            x509.load_der_x509_certificate,
            backend,
        )

        with pytest.raises(TypeError):
            cert.public_bytes("NotAnEncoding")

    @pytest.mark.parametrize(
        ("cert_path", "loader_func", "encoding"),
        [
            (
                os.path.join("x509", "v1_cert.pem"),
                x509.load_pem_x509_certificate,
                serialization.Encoding.PEM,
            ),
            (
                os.path.join("x509", "PKITS_data", "certs", "GoodCACert.crt"),
                x509.load_der_x509_certificate,
                serialization.Encoding.DER,
            ),
        ],
    )
    def test_public_bytes_match(
        self, cert_path, loader_func, encoding, backend
    ):
        cert_bytes = load_vectors_from_file(
            cert_path, lambda pemfile: pemfile.read(), mode="rb"
        )
        cert = loader_func(cert_bytes, backend)
        serialized = cert.public_bytes(encoding)
        assert serialized == cert_bytes

    def test_certificate_repr(self, backend):
        cert = _load_cert(
            os.path.join("x509", "cryptography.io.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert repr(cert) == (
            "<Certificate(subject=<Name(OU=GT48742965,OU=See www.rapidssl.com"
            "/resources/cps (c)14,OU=Domain Control Validated - RapidSSL(R),"
            "CN=www.cryptography.io)>, ...)>"
        )

    def test_parse_tls_feature_extension(self, backend):
        cert = _load_cert(
            os.path.join("x509", "tls-feature-ocsp-staple.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        ext = cert.extensions.get_extension_for_class(x509.TLSFeature)
        assert ext.critical is False
        assert ext.value == x509.TLSFeature(
            [x509.TLSFeatureType.status_request]
        )


@pytest.mark.requires_backend_interface(interface=RSABackend)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestRSACertificateRequest(object):
    @pytest.mark.parametrize(
        ("path", "loader_func"),
        [
            [
                os.path.join("x509", "requests", "rsa_sha1.pem"),
                x509.load_pem_x509_csr,
            ],
            [
                os.path.join("x509", "requests", "rsa_sha1.der"),
                x509.load_der_x509_csr,
            ],
        ],
    )
    def test_load_rsa_certificate_request(self, path, loader_func, backend):
        request = _load_cert(path, loader_func, backend)
        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        assert (
            request.signature_algorithm_oid
            == SignatureAlgorithmOID.RSA_WITH_SHA1
        )
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
        ]
        extensions = request.extensions
        assert isinstance(extensions, x509.Extensions)
        assert list(extensions) == []

    def test_get_attribute_for_oid_challenge(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "challenge.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert (
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD
            )
            == b"challenge me!"
        )

    def test_get_attribute_for_oid_multiple(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "challenge-unstructured.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert (
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD
            )
            == b"beauty"
        )
        assert (
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.UNSTRUCTURED_NAME
            )
            == b"an unstructured field"
        )

    def test_invalid_attribute_for_oid(self, backend):
        """
        This test deliberately triggers a ValueError because to parse
        CSR attributes we need to do a C cast. If we're wrong about the
        type that would be Very Bad so this test confirms we properly explode
        in the presence of the wrong types.
        """
        request = _load_cert(
            os.path.join("x509", "requests", "challenge-invalid.der"),
            x509.load_der_x509_csr,
            backend,
        )
        with pytest.raises(ValueError):
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD
            )

    def test_no_challenge_password(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha256.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        with pytest.raises(x509.AttributeNotFound) as exc:
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD
            )
        assert exc.value.oid == x509.oid.AttributeOID.CHALLENGE_PASSWORD

    @pytest.mark.parametrize(
        "loader_func", [x509.load_pem_x509_csr, x509.load_der_x509_csr]
    )
    def test_invalid_certificate_request(self, loader_func, backend):
        with pytest.raises(ValueError):
            loader_func(b"notacsr", backend)

    def test_unsupported_signature_hash_algorithm_request(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_md4.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        with pytest.raises(UnsupportedAlgorithm):
            request.signature_hash_algorithm

    def test_duplicate_extension(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "two_basic_constraints.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        with pytest.raises(x509.DuplicateExtension) as exc:
            request.extensions

        assert exc.value.oid == ExtensionOID.BASIC_CONSTRAINTS

    def test_unsupported_critical_extension(self, backend):
        request = _load_cert(
            os.path.join(
                "x509", "requests", "unsupported_extension_critical.pem"
            ),
            x509.load_pem_x509_csr,
            backend,
        )
        ext = request.extensions.get_extension_for_oid(
            x509.ObjectIdentifier("1.2.3.4")
        )
        assert ext.value.value == b"value"

    def test_unsupported_extension(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "unsupported_extension.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        extensions = request.extensions
        assert len(extensions) == 1
        assert extensions[0].oid == x509.ObjectIdentifier("1.2.3.4")
        assert extensions[0].value == x509.UnrecognizedExtension(
            x509.ObjectIdentifier("1.2.3.4"), b"value"
        )

    def test_request_basic_constraints(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "basic_constraints.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        extensions = request.extensions
        assert isinstance(extensions, x509.Extensions)
        assert list(extensions) == [
            x509.Extension(
                ExtensionOID.BASIC_CONSTRAINTS,
                True,
                x509.BasicConstraints(ca=True, path_length=1),
            ),
        ]

    def test_subject_alt_name(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "san_rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        ext = request.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(ext.value) == [
            x509.DNSName(u"cryptography.io"),
            x509.DNSName(u"sub.cryptography.io"),
        ]

    def test_public_bytes_pem(self, backend):
        # Load an existing CSR.
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        # Encode it to PEM and load it back.
        request = x509.load_pem_x509_csr(
            request.public_bytes(
                encoding=serialization.Encoding.PEM,
            ),
            backend,
        )

        # We should recover what we had to start with.
        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
        ]

    def test_public_bytes_der(self, backend):
        # Load an existing CSR.
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        # Encode it to DER and load it back.
        request = x509.load_der_x509_csr(
            request.public_bytes(
                encoding=serialization.Encoding.DER,
            ),
            backend,
        )

        # We should recover what we had to start with.
        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
        ]

    def test_signature(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.signature == binascii.unhexlify(
            b"8364c86ffbbfe0bfc9a21f831256658ca8989741b80576d36f08a934603a43b1"
            b"837246d00167a518abb1de7b51a1e5b7ebea14944800818b1a923c804f120a0d"
            b"624f6310ef79e8612755c2b01dcc7f59dfdbce0db3f2630f185f504b8c17af80"
            b"cbd364fa5fda68337153930948226cd4638287a0aed6524d3006885c19028a1e"
            b"e2f5a91d6e77dbaa0b49996ee0a0c60b55b61bd080a08bb34aa7f3e07e91f37f"
            b"6a11645be2d8654c1570dcda145ed7cc92017f7d53225d7f283f3459ec5bda41"
            b"cf6dd75d43676c543483385226b7e4fa29c8739f1b0eaf199613593991979862"
            b"e36181e8c4c270c354b7f52c128db1b70639823324c7ea24791b7bc3d7005f3b"
        )

    def test_tbs_certrequest_bytes(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.tbs_certrequest_bytes == binascii.unhexlify(
            b"308201840201003057310b3009060355040613025553310e300c060355040813"
            b"055465786173310f300d0603550407130641757374696e310d300b060355040a"
            b"130450794341311830160603550403130f63727970746f6772617068792e696f"
            b"30820122300d06092a864886f70d01010105000382010f003082010a02820101"
            b"00a840a78460cb861066dfa3045a94ba6cf1b7ab9d24c761cffddcc2cb5e3f1d"
            b"c3e4be253e7039ef14fe9d6d2304f50d9f2e1584c51530ab75086f357138bff7"
            b"b854d067d1d5f384f1f2f2c39cc3b15415e2638554ef8402648ae3ef08336f22"
            b"b7ecc6d4331c2b21c3091a7f7a9518180754a646640b60419e4cc6f5c798110a"
            b"7f030a639fe87e33b4776dfcd993940ec776ab57a181ad8598857976dc303f9a"
            b"573ca619ab3fe596328e92806b828683edc17cc256b41948a2bfa8d047d2158d"
            b"3d8e069aa05fa85b3272abb1c4b4422b6366f3b70e642377b145cd6259e5d3e7"
            b"db048d51921e50766a37b1b130ee6b11f507d20a834001e8de16a92c14f2e964"
            b"a30203010001a000"
        )
        request.public_key().verify(
            request.signature,
            request.tbs_certrequest_bytes,
            padding.PKCS1v15(),
            request.signature_hash_algorithm,
        )

    def test_public_bytes_invalid_encoding(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        with pytest.raises(TypeError):
            request.public_bytes("NotAnEncoding")

    def test_signature_invalid(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "invalid_signature.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert not request.is_signature_valid

    def test_signature_valid(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "rsa_sha256.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.is_signature_valid

    @pytest.mark.parametrize(
        ("request_path", "loader_func", "encoding"),
        [
            (
                os.path.join("x509", "requests", "rsa_sha1.pem"),
                x509.load_pem_x509_csr,
                serialization.Encoding.PEM,
            ),
            (
                os.path.join("x509", "requests", "rsa_sha1.der"),
                x509.load_der_x509_csr,
                serialization.Encoding.DER,
            ),
        ],
    )
    def test_public_bytes_match(
        self, request_path, loader_func, encoding, backend
    ):
        request_bytes = load_vectors_from_file(
            request_path, lambda pemfile: pemfile.read(), mode="rb"
        )
        request = loader_func(request_bytes, backend)
        serialized = request.public_bytes(encoding)
        assert serialized == request_bytes

    def test_eq(self, backend):
        request1 = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        request2 = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        assert request1 == request2

    def test_ne(self, backend):
        request1 = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        request2 = _load_cert(
            os.path.join("x509", "requests", "san_rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        assert request1 != request2
        assert request1 != object()

    def test_hash(self, backend):
        request1 = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        request2 = _load_cert(
            os.path.join("x509", "requests", "rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        request3 = _load_cert(
            os.path.join("x509", "requests", "san_rsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )

        assert hash(request1) == hash(request2)
        assert hash(request1) != hash(request3)

    def test_build_cert(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name(
                    [
                        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                        x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
                        x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
                        x509.NameAttribute(
                            NameOID.COMMON_NAME, u"cryptography.io"
                        ),
                    ]
                )
            )
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                        x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
                        x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
                        x509.NameAttribute(
                            NameOID.COMMON_NAME, u"cryptography.io"
                        ),
                    ]
                )
            )
            .public_key(subject_private_key.public_key())
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA1(), backend)

        assert cert.version is x509.Version.v3
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        basic_constraints = cert.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None
        subject_alternative_name = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(subject_alternative_name.value) == [
            x509.DNSName(u"cryptography.io"),
        ]

    def test_build_cert_private_type_encoding(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)
        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)
        name = x509.Name(
            [
                x509.NameAttribute(
                    NameOID.STATE_OR_PROVINCE_NAME,
                    u"Texas",
                    _ASN1Type.PrintableString,
                ),
                x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
                x509.NameAttribute(
                    NameOID.COMMON_NAME,
                    u"cryptography.io",
                    _ASN1Type.IA5String,
                ),
            ]
        )
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(name)
            .subject_name(name)
            .public_key(subject_private_key.public_key())
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )
        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)

        for dn in (cert.subject, cert.issuer):
            assert (
                dn.get_attributes_for_oid(NameOID.STATE_OR_PROVINCE_NAME)[
                    0
                ]._type
                == _ASN1Type.PrintableString
            )
            assert (
                dn.get_attributes_for_oid(NameOID.STATE_OR_PROVINCE_NAME)[
                    0
                ]._type
                == _ASN1Type.PrintableString
            )
            assert (
                dn.get_attributes_for_oid(NameOID.LOCALITY_NAME)[0]._type
                == _ASN1Type.UTF8String
            )

    def test_build_cert_printable_string_country_name(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name(
                    [
                        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                        x509.NameAttribute(
                            NameOID.JURISDICTION_COUNTRY_NAME, u"US"
                        ),
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                        x509.NameAttribute(
                            NameOID.JURISDICTION_COUNTRY_NAME, u"US"
                        ),
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)

        parsed = _parse_cert(cert.public_bytes(serialization.Encoding.DER))
        subject = parsed.subject
        issuer = parsed.issuer

        def read_next_rdn_value_tag(reader):
            # Assume each RDN has a single attribute.
            with reader.read_element(SET) as rdn:
                attribute = rdn.read_element(SEQUENCE)

            with attribute:
                _ = attribute.read_element(OBJECT_IDENTIFIER)
                tag, value = attribute.read_any_element()
                return tag

        # Check that each value was encoded as an ASN.1 PRINTABLESTRING.
        assert read_next_rdn_value_tag(subject) == PRINTABLE_STRING
        assert read_next_rdn_value_tag(issuer) == PRINTABLE_STRING
        if (
            # This only works correctly in OpenSSL 1.1.0f+ and 1.0.2l+
            backend._lib.CRYPTOGRAPHY_OPENSSL_110F_OR_GREATER
        ):
            assert read_next_rdn_value_tag(subject) == PRINTABLE_STRING
            assert read_next_rdn_value_tag(issuer) == PRINTABLE_STRING


class TestCertificateBuilder(object):
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_checks_for_unsupported_extensions(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(private_key.public_key())
            .serial_number(777)
            .not_valid_before(datetime.datetime(1999, 1, 1))
            .not_valid_after(datetime.datetime(2020, 1, 1))
            .add_extension(DummyExtension(), False)
        )

        with pytest.raises(NotImplementedError):
            builder.sign(private_key, hashes.SHA1(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_encode_nonstandard_aia(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        aia = x509.AuthorityInformationAccess(
            [
                x509.AccessDescription(
                    x509.ObjectIdentifier("2.999.7"),
                    x509.UniformResourceIdentifier(u"http://example.com"),
                ),
            ]
        )

        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(private_key.public_key())
            .serial_number(777)
            .not_valid_before(datetime.datetime(1999, 1, 1))
            .not_valid_after(datetime.datetime(2020, 1, 1))
            .add_extension(aia, False)
        )

        builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_encode_nonstandard_sia(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        sia = x509.SubjectInformationAccess(
            [
                x509.AccessDescription(
                    x509.ObjectIdentifier("2.999.7"),
                    x509.UniformResourceIdentifier(u"http://example.com"),
                ),
            ]
        )

        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(private_key.public_key())
            .serial_number(777)
            .not_valid_before(datetime.datetime(2015, 1, 1))
            .not_valid_after(datetime.datetime(2040, 1, 1))
            .add_extension(sia, False)
        )

        cert = builder.sign(private_key, hashes.SHA256(), backend)
        ext = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_INFORMATION_ACCESS
        )
        assert ext.value == sia

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_subject_dn_asn1_types(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        name = x509.Name(
            [
                x509.NameAttribute(NameOID.COMMON_NAME, u"mysite.com"),
                x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                x509.NameAttribute(NameOID.LOCALITY_NAME, u"value"),
                x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"value"),
                x509.NameAttribute(NameOID.STREET_ADDRESS, u"value"),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"value"),
                x509.NameAttribute(NameOID.ORGANIZATIONAL_UNIT_NAME, u"value"),
                x509.NameAttribute(NameOID.SERIAL_NUMBER, u"value"),
                x509.NameAttribute(NameOID.SURNAME, u"value"),
                x509.NameAttribute(NameOID.GIVEN_NAME, u"value"),
                x509.NameAttribute(NameOID.TITLE, u"value"),
                x509.NameAttribute(NameOID.GENERATION_QUALIFIER, u"value"),
                x509.NameAttribute(NameOID.X500_UNIQUE_IDENTIFIER, u"value"),
                x509.NameAttribute(NameOID.DN_QUALIFIER, u"value"),
                x509.NameAttribute(NameOID.PSEUDONYM, u"value"),
                x509.NameAttribute(NameOID.USER_ID, u"value"),
                x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"value"),
                x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"value"),
                x509.NameAttribute(NameOID.JURISDICTION_COUNTRY_NAME, u"US"),
                x509.NameAttribute(
                    NameOID.JURISDICTION_LOCALITY_NAME, u"value"
                ),
                x509.NameAttribute(
                    NameOID.JURISDICTION_STATE_OR_PROVINCE_NAME, u"value"
                ),
                x509.NameAttribute(NameOID.BUSINESS_CATEGORY, u"value"),
                x509.NameAttribute(NameOID.POSTAL_ADDRESS, u"value"),
                x509.NameAttribute(NameOID.POSTAL_CODE, u"value"),
            ]
        )
        cert = (
            x509.CertificateBuilder()
            .subject_name(name)
            .issuer_name(name)
            .public_key(private_key.public_key())
            .serial_number(777)
            .not_valid_before(datetime.datetime(1999, 1, 1))
            .not_valid_after(datetime.datetime(2020, 1, 1))
            .sign(private_key, hashes.SHA256(), backend)
        )

        for dn in (cert.subject, cert.issuer):
            for oid, asn1_type in TestNameAttribute.EXPECTED_TYPES:
                assert dn.get_attributes_for_oid(oid)[0]._type == asn1_type

    @pytest.mark.parametrize(
        ("not_valid_before", "not_valid_after"),
        [
            [datetime.datetime(1970, 2, 1), datetime.datetime(9999, 1, 1)],
            [datetime.datetime(1970, 2, 1), datetime.datetime(9999, 12, 31)],
        ],
    )
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_extreme_times(self, not_valid_before, not_valid_after, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(private_key.public_key())
            .serial_number(777)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )
        cert = builder.sign(private_key, hashes.SHA256(), backend)
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        parsed = _parse_cert(cert.public_bytes(serialization.Encoding.DER))
        assert parsed.not_before_tag == UTC_TIME
        assert parsed.not_after_tag == GENERALIZED_TIME

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_subject_name(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_issuer_name(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_public_key(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_not_valid_before(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_not_valid_after(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_no_serial_number(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        with pytest.raises(ValueError):
            builder.sign(subject_private_key, hashes.SHA256(), backend)

    def test_issuer_name_must_be_a_name_type(self):
        builder = x509.CertificateBuilder()

        with pytest.raises(TypeError):
            builder.issuer_name("subject")

        with pytest.raises(TypeError):
            builder.issuer_name(object)

    def test_issuer_name_may_only_be_set_once(self):
        name = x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        builder = x509.CertificateBuilder().issuer_name(name)

        with pytest.raises(ValueError):
            builder.issuer_name(name)

    def test_subject_name_must_be_a_name_type(self):
        builder = x509.CertificateBuilder()

        with pytest.raises(TypeError):
            builder.subject_name("subject")

        with pytest.raises(TypeError):
            builder.subject_name(object)

    def test_subject_name_may_only_be_set_once(self):
        name = x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        builder = x509.CertificateBuilder().subject_name(name)

        with pytest.raises(ValueError):
            builder.subject_name(name)

    def test_not_valid_before_after_not_valid_after(self):
        builder = x509.CertificateBuilder()

        builder = builder.not_valid_after(datetime.datetime(2002, 1, 1, 12, 1))
        with pytest.raises(ValueError):
            builder.not_valid_before(datetime.datetime(2003, 1, 1, 12, 1))

    def test_not_valid_after_before_not_valid_before(self):
        builder = x509.CertificateBuilder()

        builder = builder.not_valid_before(
            datetime.datetime(2002, 1, 1, 12, 1)
        )
        with pytest.raises(ValueError):
            builder.not_valid_after(datetime.datetime(2001, 1, 1, 12, 1))

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_public_key_must_be_public_key(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateBuilder()

        with pytest.raises(TypeError):
            builder.public_key(private_key)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_public_key_may_only_be_set_once(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        public_key = private_key.public_key()
        builder = x509.CertificateBuilder().public_key(public_key)

        with pytest.raises(ValueError):
            builder.public_key(public_key)

    def test_serial_number_must_be_an_integer_type(self):
        with pytest.raises(TypeError):
            x509.CertificateBuilder().serial_number(10.0)

    def test_serial_number_must_be_non_negative(self):
        with pytest.raises(ValueError):
            x509.CertificateBuilder().serial_number(-1)

    def test_serial_number_must_be_positive(self):
        with pytest.raises(ValueError):
            x509.CertificateBuilder().serial_number(0)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_minimal_serial_number(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number(1)
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"RU")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"RU")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        cert = builder.sign(subject_private_key, hashes.SHA256(), backend)
        assert cert.serial_number == 1

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_biggest_serial_number(self, backend):
        subject_private_key = RSA_KEY_2048.private_key(backend)
        builder = (
            x509.CertificateBuilder()
            .serial_number((1 << 159) - 1)
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"RU")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"RU")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
        )
        cert = builder.sign(subject_private_key, hashes.SHA256(), backend)
        assert cert.serial_number == (1 << 159) - 1

    def test_serial_number_must_be_less_than_160_bits_long(self):
        with pytest.raises(ValueError):
            x509.CertificateBuilder().serial_number(1 << 159)

    def test_serial_number_may_only_be_set_once(self):
        builder = x509.CertificateBuilder().serial_number(10)

        with pytest.raises(ValueError):
            builder.serial_number(20)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_aware_not_valid_after(self, backend):
        time = datetime.datetime(2012, 1, 16, 22, 43)
        tz = pytz.timezone("US/Pacific")
        time = tz.localize(time)
        utc_time = datetime.datetime(2012, 1, 17, 6, 43)
        private_key = RSA_KEY_2048.private_key(backend)
        cert_builder = x509.CertificateBuilder().not_valid_after(time)
        cert_builder = (
            cert_builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(utc_time - datetime.timedelta(days=365))
        )

        cert = cert_builder.sign(private_key, hashes.SHA256(), backend)
        assert cert.not_valid_after == utc_time

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_earliest_time(self, backend):
        time = datetime.datetime(1950, 1, 1)
        private_key = RSA_KEY_2048.private_key(backend)
        cert_builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(time)
            .not_valid_after(time)
        )
        cert = cert_builder.sign(private_key, hashes.SHA256(), backend)
        assert cert.not_valid_before == time
        assert cert.not_valid_after == time
        parsed = _parse_cert(cert.public_bytes(serialization.Encoding.DER))
        assert parsed.not_before_tag == UTC_TIME
        assert parsed.not_after_tag == UTC_TIME

    def test_invalid_not_valid_after(self):
        with pytest.raises(TypeError):
            x509.CertificateBuilder().not_valid_after(104204304504)

        with pytest.raises(TypeError):
            x509.CertificateBuilder().not_valid_after(datetime.time())

        with pytest.raises(ValueError):
            x509.CertificateBuilder().not_valid_after(
                datetime.datetime(1940, 8, 10)
            )

    def test_not_valid_after_may_only_be_set_once(self):
        builder = x509.CertificateBuilder().not_valid_after(
            datetime.datetime.now()
        )

        with pytest.raises(ValueError):
            builder.not_valid_after(datetime.datetime.now())

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_aware_not_valid_before(self, backend):
        time = datetime.datetime(2012, 1, 16, 22, 43)
        tz = pytz.timezone("US/Pacific")
        time = tz.localize(time)
        utc_time = datetime.datetime(2012, 1, 17, 6, 43)
        private_key = RSA_KEY_2048.private_key(backend)
        cert_builder = x509.CertificateBuilder().not_valid_before(time)
        cert_builder = (
            cert_builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_after(utc_time + datetime.timedelta(days=366))
        )

        cert = cert_builder.sign(private_key, hashes.SHA256(), backend)
        assert cert.not_valid_before == utc_time

    def test_invalid_not_valid_before(self):
        with pytest.raises(TypeError):
            x509.CertificateBuilder().not_valid_before(104204304504)

        with pytest.raises(TypeError):
            x509.CertificateBuilder().not_valid_before(datetime.time())

        with pytest.raises(ValueError):
            x509.CertificateBuilder().not_valid_before(
                datetime.datetime(1940, 8, 10)
            )

    def test_not_valid_before_may_only_be_set_once(self):
        builder = x509.CertificateBuilder().not_valid_before(
            datetime.datetime.now()
        )

        with pytest.raises(ValueError):
            builder.not_valid_before(datetime.datetime.now())

    def test_add_extension_checks_for_duplicates(self):
        builder = x509.CertificateBuilder().add_extension(
            x509.BasicConstraints(ca=False, path_length=None),
            True,
        )

        with pytest.raises(ValueError):
            builder.add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )

    def test_add_invalid_extension_type(self):
        builder = x509.CertificateBuilder()

        with pytest.raises(TypeError):
            builder.add_extension(object(), False)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.parametrize("algorithm", [object(), None])
    def test_sign_with_unsupported_hash(self, algorithm, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateBuilder()
        builder = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )

        with pytest.raises(TypeError):
            builder.sign(private_key, algorithm, backend)

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed25519_supported(),
        skip_message="Requires OpenSSL with Ed25519 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_sign_with_unsupported_hash_ed25519(self, backend):
        private_key = ed25519.Ed25519PrivateKey.generate()
        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed448_supported(),
        skip_message="Requires OpenSSL with Ed448 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_sign_with_unsupported_hash_ed448(self, backend):
        private_key = ed448.Ed448PrivateKey.generate()
        builder = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_rsa_with_md5(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateBuilder()
        builder = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )
        cert = builder.sign(private_key, hashes.MD5(), backend)
        assert isinstance(cert.signature_hash_algorithm, hashes.MD5)

    @pytest.mark.requires_backend_interface(interface=DSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_dsa_with_md5(self, backend):
        private_key = DSA_KEY_2048.private_key(backend)
        builder = x509.CertificateBuilder()
        builder = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.MD5(), backend)

    @pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_ec_with_md5(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        private_key = EC_KEY_SECP256R1.private_key(backend)
        builder = x509.CertificateBuilder()
        builder = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .serial_number(1)
            .public_key(private_key.public_key())
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2032, 1, 1, 12, 1))
        )
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.MD5(), backend)

    @pytest.mark.requires_backend_interface(interface=DSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_dsa_private_key(self, backend):
        issuer_private_key = DSA_KEY_2048.private_key(backend)
        subject_private_key = DSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA1(), backend)

        assert cert.version is x509.Version.v3
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        basic_constraints = cert.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None
        subject_alternative_name = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(subject_alternative_name.value) == [
            x509.DNSName(u"cryptography.io"),
        ]

    @pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_ec_private_key(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        issuer_private_key = ec.generate_private_key(ec.SECP256R1(), backend)
        subject_private_key = ec.generate_private_key(ec.SECP256R1(), backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA1(), backend)

        assert cert.version is x509.Version.v3
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        basic_constraints = cert.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None
        subject_alternative_name = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(subject_alternative_name.value) == [
            x509.DNSName(u"cryptography.io"),
        ]

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed25519_supported(),
        skip_message="Requires OpenSSL with Ed25519 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_ed25519(self, backend):
        issuer_private_key = ed25519.Ed25519PrivateKey.generate()
        subject_private_key = ed25519.Ed25519PrivateKey.generate()

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, None, backend)
        issuer_private_key.public_key().verify(
            cert.signature, cert.tbs_certificate_bytes
        )
        assert cert.signature_algorithm_oid == SignatureAlgorithmOID.ED25519
        assert cert.signature_hash_algorithm is None
        assert isinstance(cert.public_key(), ed25519.Ed25519PublicKey)
        assert cert.version is x509.Version.v3
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        basic_constraints = cert.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None
        subject_alternative_name = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(subject_alternative_name.value) == [
            x509.DNSName(u"cryptography.io"),
        ]

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed25519_supported(),
        skip_message="Requires OpenSSL with Ed25519 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_cert_with_public_ed25519_rsa_sig(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = ed25519.Ed25519PrivateKey.generate()

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)
        issuer_private_key.public_key().verify(
            cert.signature,
            cert.tbs_certificate_bytes,
            padding.PKCS1v15(),
            cert.signature_hash_algorithm,
        )
        assert cert.signature_algorithm_oid == (
            SignatureAlgorithmOID.RSA_WITH_SHA256
        )
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA256)
        assert isinstance(cert.public_key(), ed25519.Ed25519PublicKey)

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed448_supported(),
        skip_message="Requires OpenSSL with Ed448 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_ed448(self, backend):
        issuer_private_key = ed448.Ed448PrivateKey.generate()
        subject_private_key = ed448.Ed448PrivateKey.generate()

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                True,
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, None, backend)
        issuer_private_key.public_key().verify(
            cert.signature, cert.tbs_certificate_bytes
        )
        assert cert.signature_algorithm_oid == SignatureAlgorithmOID.ED448
        assert cert.signature_hash_algorithm is None
        assert isinstance(cert.public_key(), ed448.Ed448PublicKey)
        assert cert.version is x509.Version.v3
        assert cert.not_valid_before == not_valid_before
        assert cert.not_valid_after == not_valid_after
        basic_constraints = cert.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None
        subject_alternative_name = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(subject_alternative_name.value) == [
            x509.DNSName(u"cryptography.io"),
        ]

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed448_supported(),
        skip_message="Requires OpenSSL with Ed448 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_cert_with_public_ed448_rsa_sig(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = ed448.Ed448PrivateKey.generate()

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)
        issuer_private_key.public_key().verify(
            cert.signature,
            cert.tbs_certificate_bytes,
            padding.PKCS1v15(),
            cert.signature_hash_algorithm,
        )
        assert cert.signature_algorithm_oid == (
            SignatureAlgorithmOID.RSA_WITH_SHA256
        )
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA256)
        assert isinstance(cert.public_key(), ed448.Ed448PublicKey)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_rsa_key_too_small(self, backend):
        issuer_private_key = RSA_KEY_512.private_key(backend)
        subject_private_key = RSA_KEY_512.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        with pytest.raises(ValueError):
            builder.sign(issuer_private_key, hashes.SHA512(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    @pytest.mark.parametrize(
        "add_ext",
        [
            x509.SubjectAlternativeName(
                [
                    # These examples exist to verify compatibility with
                    # certificates that have utf8 encoded data in the ia5string
                    x509.DNSName._init_without_validation(u"a\xedt\xe1s.test"),
                    x509.RFC822Name._init_without_validation(
                        u"test@a\xedt\xe1s.test"
                    ),
                    x509.UniformResourceIdentifier._init_without_validation(
                        u"http://a\xedt\xe1s.test"
                    ),
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        [u"http://other.com/cps"],
                    )
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        None,
                    )
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        [
                            u"http://example.com/cps",
                            u"http://other.com/cps",
                            x509.UserNotice(
                                x509.NoticeReference(u"my org", [1, 2, 3, 4]),
                                u"thing",
                            ),
                        ],
                    )
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        [
                            u"http://example.com/cps",
                            x509.UserNotice(
                                x509.NoticeReference(
                                    u"UTF8\u2122'", [1, 2, 3, 4]
                                ),
                                u"We heart UTF8!\u2122",
                            ),
                        ],
                    )
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        [x509.UserNotice(None, u"thing")],
                    )
                ]
            ),
            x509.CertificatePolicies(
                [
                    x509.PolicyInformation(
                        x509.ObjectIdentifier("2.16.840.1.12345.1.2.3.4.1"),
                        [
                            x509.UserNotice(
                                x509.NoticeReference(u"my org", [1, 2, 3, 4]),
                                None,
                            )
                        ],
                    )
                ]
            ),
            x509.IssuerAlternativeName(
                [
                    x509.DNSName(u"myissuer"),
                    x509.RFC822Name(u"email@domain.com"),
                ]
            ),
            x509.ExtendedKeyUsage(
                [
                    ExtendedKeyUsageOID.CLIENT_AUTH,
                    ExtendedKeyUsageOID.SERVER_AUTH,
                    ExtendedKeyUsageOID.CODE_SIGNING,
                ]
            ),
            x509.InhibitAnyPolicy(3),
            x509.TLSFeature([x509.TLSFeatureType.status_request]),
            x509.TLSFeature([x509.TLSFeatureType.status_request_v2]),
            x509.TLSFeature(
                [
                    x509.TLSFeatureType.status_request,
                    x509.TLSFeatureType.status_request_v2,
                ]
            ),
            x509.NameConstraints(
                permitted_subtrees=[
                    x509.IPAddress(ipaddress.IPv4Network(u"192.168.0.0/24")),
                    x509.IPAddress(ipaddress.IPv4Network(u"192.168.0.0/29")),
                    x509.IPAddress(ipaddress.IPv4Network(u"127.0.0.1/32")),
                    x509.IPAddress(ipaddress.IPv4Network(u"8.0.0.0/8")),
                    x509.IPAddress(ipaddress.IPv4Network(u"0.0.0.0/0")),
                    x509.IPAddress(
                        ipaddress.IPv6Network(u"FF:0:0:0:0:0:0:0/96")
                    ),
                    x509.IPAddress(
                        ipaddress.IPv6Network(u"FF:FF:0:0:0:0:0:0/128")
                    ),
                ],
                excluded_subtrees=[x509.DNSName(u"name.local")],
            ),
            x509.NameConstraints(
                permitted_subtrees=[
                    x509.IPAddress(ipaddress.IPv4Network(u"0.0.0.0/0")),
                ],
                excluded_subtrees=None,
            ),
            x509.NameConstraints(
                permitted_subtrees=None,
                excluded_subtrees=[x509.DNSName(u"name.local")],
            ),
            x509.PolicyConstraints(
                require_explicit_policy=None, inhibit_policy_mapping=1
            ),
            x509.PolicyConstraints(
                require_explicit_policy=3, inhibit_policy_mapping=1
            ),
            x509.PolicyConstraints(
                require_explicit_policy=0, inhibit_policy_mapping=None
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=None,
                        relative_name=x509.RelativeDistinguishedName(
                            [
                                x509.NameAttribute(
                                    NameOID.COMMON_NAME,
                                    u"indirect CRL for indirectCRL CA3",
                                ),
                            ]
                        ),
                        reasons=None,
                        crl_issuer=[
                            x509.DirectoryName(
                                x509.Name(
                                    [
                                        x509.NameAttribute(
                                            NameOID.COUNTRY_NAME, u"US"
                                        ),
                                        x509.NameAttribute(
                                            NameOID.ORGANIZATION_NAME,
                                            u"Test Certificates 2011",
                                        ),
                                        x509.NameAttribute(
                                            NameOID.ORGANIZATIONAL_UNIT_NAME,
                                            u"indirectCRL CA3 cRLIssuer",
                                        ),
                                    ]
                                )
                            )
                        ],
                    )
                ]
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=[
                            x509.DirectoryName(
                                x509.Name(
                                    [
                                        x509.NameAttribute(
                                            NameOID.COUNTRY_NAME, u"US"
                                        ),
                                    ]
                                )
                            )
                        ],
                        relative_name=None,
                        reasons=None,
                        crl_issuer=[
                            x509.DirectoryName(
                                x509.Name(
                                    [
                                        x509.NameAttribute(
                                            NameOID.ORGANIZATION_NAME,
                                            u"cryptography Testing",
                                        ),
                                    ]
                                )
                            )
                        ],
                    )
                ]
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=[
                            x509.UniformResourceIdentifier(
                                u"http://myhost.com/myca.crl"
                            ),
                            x509.UniformResourceIdentifier(
                                u"http://backup.myhost.com/myca.crl"
                            ),
                        ],
                        relative_name=None,
                        reasons=frozenset(
                            [
                                x509.ReasonFlags.key_compromise,
                                x509.ReasonFlags.ca_compromise,
                            ]
                        ),
                        crl_issuer=[
                            x509.DirectoryName(
                                x509.Name(
                                    [
                                        x509.NameAttribute(
                                            NameOID.COUNTRY_NAME, u"US"
                                        ),
                                        x509.NameAttribute(
                                            NameOID.COMMON_NAME,
                                            u"cryptography CA",
                                        ),
                                    ]
                                )
                            )
                        ],
                    )
                ]
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=[
                            x509.UniformResourceIdentifier(
                                u"http://domain.com/some.crl"
                            )
                        ],
                        relative_name=None,
                        reasons=frozenset(
                            [
                                x509.ReasonFlags.key_compromise,
                                x509.ReasonFlags.ca_compromise,
                                x509.ReasonFlags.affiliation_changed,
                                x509.ReasonFlags.superseded,
                                x509.ReasonFlags.privilege_withdrawn,
                                x509.ReasonFlags.cessation_of_operation,
                                x509.ReasonFlags.aa_compromise,
                                x509.ReasonFlags.certificate_hold,
                            ]
                        ),
                        crl_issuer=None,
                    )
                ]
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=None,
                        relative_name=None,
                        reasons=None,
                        crl_issuer=[
                            x509.DirectoryName(
                                x509.Name(
                                    [
                                        x509.NameAttribute(
                                            NameOID.COMMON_NAME,
                                            u"cryptography CA",
                                        ),
                                    ]
                                )
                            )
                        ],
                    )
                ]
            ),
            x509.CRLDistributionPoints(
                [
                    x509.DistributionPoint(
                        full_name=[
                            x509.UniformResourceIdentifier(
                                u"http://domain.com/some.crl"
                            )
                        ],
                        relative_name=None,
                        reasons=frozenset([x509.ReasonFlags.aa_compromise]),
                        crl_issuer=None,
                    )
                ]
            ),
            x509.FreshestCRL(
                [
                    x509.DistributionPoint(
                        full_name=[
                            x509.UniformResourceIdentifier(
                                u"http://domain.com/some.crl"
                            )
                        ],
                        relative_name=None,
                        reasons=frozenset(
                            [
                                x509.ReasonFlags.key_compromise,
                                x509.ReasonFlags.ca_compromise,
                                x509.ReasonFlags.affiliation_changed,
                                x509.ReasonFlags.superseded,
                                x509.ReasonFlags.privilege_withdrawn,
                                x509.ReasonFlags.cessation_of_operation,
                                x509.ReasonFlags.aa_compromise,
                                x509.ReasonFlags.certificate_hold,
                            ]
                        ),
                        crl_issuer=None,
                    )
                ]
            ),
            x509.FreshestCRL(
                [
                    x509.DistributionPoint(
                        full_name=None,
                        relative_name=x509.RelativeDistinguishedName(
                            [
                                x509.NameAttribute(
                                    NameOID.COMMON_NAME,
                                    u"indirect CRL for indirectCRL CA3",
                                ),
                            ]
                        ),
                        reasons=None,
                        crl_issuer=None,
                    )
                ]
            ),
            x509.FreshestCRL(
                [
                    x509.DistributionPoint(
                        full_name=None,
                        relative_name=x509.RelativeDistinguishedName(
                            [
                                x509.NameAttribute(
                                    NameOID.COMMON_NAME,
                                    u"indirect CRL for indirectCRL CA3",
                                ),
                                x509.NameAttribute(
                                    NameOID.COUNTRY_NAME, u"US"
                                ),
                            ]
                        ),
                        reasons=None,
                        crl_issuer=None,
                    )
                ]
            ),
        ],
    )
    def test_ext(self, add_ext, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        cert = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
            .public_key(subject_private_key.public_key())
            .serial_number(123)
            .add_extension(add_ext, critical=False)
            .sign(issuer_private_key, hashes.SHA256(), backend)
        )

        ext = cert.extensions.get_extension_for_class(type(add_ext))
        assert ext.critical is False
        assert ext.value == add_ext

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_key_usage(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        cert = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
            .public_key(subject_private_key.public_key())
            .serial_number(123)
            .add_extension(
                x509.KeyUsage(
                    digital_signature=True,
                    content_commitment=True,
                    key_encipherment=False,
                    data_encipherment=False,
                    key_agreement=False,
                    key_cert_sign=True,
                    crl_sign=False,
                    encipher_only=False,
                    decipher_only=False,
                ),
                critical=False,
            )
            .sign(issuer_private_key, hashes.SHA256(), backend)
        )

        ext = cert.extensions.get_extension_for_oid(ExtensionOID.KEY_USAGE)
        assert ext.critical is False
        assert ext.value == x509.KeyUsage(
            digital_signature=True,
            content_commitment=True,
            key_encipherment=False,
            data_encipherment=False,
            key_agreement=False,
            key_cert_sign=True,
            crl_sign=False,
            encipher_only=False,
            decipher_only=False,
        )

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_ca_request_with_path_length_none(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=None), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        loaded_request = x509.load_pem_x509_csr(
            request.public_bytes(encoding=serialization.Encoding.PEM), backend
        )
        subject = loaded_request.subject
        assert isinstance(subject, x509.Name)
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.path_length is None

    @pytest.mark.parametrize(
        "unrecognized",
        [
            x509.UnrecognizedExtension(
                x509.ObjectIdentifier("1.2.3.4.5"),
                b"abcdef",
            )
        ],
    )
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_unrecognized_extension(self, backend, unrecognized):
        private_key = RSA_KEY_2048.private_key(backend)

        cert = (
            x509.CertificateBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(x509.OID_COUNTRY_NAME, u"US")])
            )
            .issuer_name(
                x509.Name([x509.NameAttribute(x509.OID_COUNTRY_NAME, u"US")])
            )
            .not_valid_before(datetime.datetime(2002, 1, 1, 12, 1))
            .not_valid_after(datetime.datetime(2030, 12, 31, 8, 30))
            .public_key(private_key.public_key())
            .serial_number(123)
            .add_extension(unrecognized, critical=False)
            .sign(private_key, hashes.SHA256(), backend)
        )

        ext = cert.extensions.get_extension_for_oid(unrecognized.oid)

        assert ext.value == unrecognized


@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestCertificateSigningRequestBuilder(object):
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_sign_invalid_hash_algorithm(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([])
        )
        with pytest.raises(TypeError):
            builder.sign(private_key, "NotAHash", backend)

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed25519_supported(),
        skip_message="Requires OpenSSL with Ed25519 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_request_with_unsupported_hash_ed25519(self, backend):
        private_key = ed25519.Ed25519PrivateKey.generate()
        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed448_supported(),
        skip_message="Requires OpenSSL with Ed448 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_request_with_unsupported_hash_ed448(self, backend):
        private_key = ed448.Ed448PrivateKey.generate()
        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_rsa_with_md5(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")])
        )
        request = builder.sign(private_key, hashes.MD5(), backend)
        assert isinstance(request.signature_hash_algorithm, hashes.MD5)

    @pytest.mark.requires_backend_interface(interface=DSABackend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_dsa_with_md5(self, backend):
        private_key = DSA_KEY_2048.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")])
        )
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.MD5(), backend)

    @pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
    @pytest.mark.supported(
        only_if=lambda backend: backend.hash_supported(hashes.MD5()),
        skip_message="Requires OpenSSL with MD5 support",
    )
    def test_sign_ec_with_md5(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        private_key = EC_KEY_SECP256R1.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")])
        )
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.MD5(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_no_subject_name(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        builder = x509.CertificateSigningRequestBuilder()
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_ca_request_with_rsa(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_ca_request_with_unicode(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.ORGANIZATION_NAME, u"PyCA\U0001f37a"
                        ),
                    ]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        loaded_request = x509.load_pem_x509_csr(
            request.public_bytes(encoding=serialization.Encoding.PEM), backend
        )
        subject = loaded_request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA\U0001f37a"),
        ]

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_subject_dn_asn1_types(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(NameOID.COMMON_NAME, u"mysite.com"),
                        x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                        x509.NameAttribute(NameOID.LOCALITY_NAME, u"value"),
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"value"
                        ),
                        x509.NameAttribute(NameOID.STREET_ADDRESS, u"value"),
                        x509.NameAttribute(
                            NameOID.ORGANIZATION_NAME, u"value"
                        ),
                        x509.NameAttribute(
                            NameOID.ORGANIZATIONAL_UNIT_NAME, u"value"
                        ),
                        x509.NameAttribute(NameOID.SERIAL_NUMBER, u"value"),
                        x509.NameAttribute(NameOID.SURNAME, u"value"),
                        x509.NameAttribute(NameOID.GIVEN_NAME, u"value"),
                        x509.NameAttribute(NameOID.TITLE, u"value"),
                        x509.NameAttribute(
                            NameOID.GENERATION_QUALIFIER, u"value"
                        ),
                        x509.NameAttribute(
                            NameOID.X500_UNIQUE_IDENTIFIER, u"value"
                        ),
                        x509.NameAttribute(NameOID.DN_QUALIFIER, u"value"),
                        x509.NameAttribute(NameOID.PSEUDONYM, u"value"),
                        x509.NameAttribute(NameOID.USER_ID, u"value"),
                        x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"value"),
                        x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"value"),
                        x509.NameAttribute(
                            NameOID.JURISDICTION_COUNTRY_NAME, u"US"
                        ),
                        x509.NameAttribute(
                            NameOID.JURISDICTION_LOCALITY_NAME, u"value"
                        ),
                        x509.NameAttribute(
                            NameOID.JURISDICTION_STATE_OR_PROVINCE_NAME,
                            u"value",
                        ),
                        x509.NameAttribute(
                            NameOID.BUSINESS_CATEGORY, u"value"
                        ),
                        x509.NameAttribute(NameOID.POSTAL_ADDRESS, u"value"),
                        x509.NameAttribute(NameOID.POSTAL_CODE, u"value"),
                    ]
                )
            )
            .sign(private_key, hashes.SHA256(), backend)
        )
        for oid, asn1_type in TestNameAttribute.EXPECTED_TYPES:
            assert (
                request.subject.get_attributes_for_oid(oid)[0]._type
                == asn1_type
            )

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_ca_request_with_multivalue_rdns(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        subject = x509.Name(
            [
                x509.RelativeDistinguishedName(
                    [
                        x509.NameAttribute(NameOID.TITLE, u"Test"),
                        x509.NameAttribute(NameOID.COMMON_NAME, u"Multivalue"),
                        x509.NameAttribute(NameOID.SURNAME, u"RDNs"),
                    ]
                ),
                x509.RelativeDistinguishedName(
                    [x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA")]
                ),
            ]
        )

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(subject)
            .sign(private_key, hashes.SHA1(), backend)
        )

        loaded_request = x509.load_pem_x509_csr(
            request.public_bytes(encoding=serialization.Encoding.PEM), backend
        )
        assert isinstance(loaded_request.subject, x509.Name)
        assert loaded_request.subject == subject

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_build_nonca_request_with_rsa(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.BasicConstraints(ca=False, path_length=None),
                critical=True,
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is False
        assert basic_constraints.value.path_length is None

    @pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
    def test_build_ca_request_with_ec(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        private_key = ec.generate_private_key(ec.SECP256R1(), backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, ec.EllipticCurvePublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed25519_supported(),
        skip_message="Requires OpenSSL with Ed25519 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_ca_request_with_ed25519(self, backend):
        private_key = ed25519.Ed25519PrivateKey.generate()

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, None, backend)
        )

        assert request.signature_hash_algorithm is None
        public_key = request.public_key()
        assert isinstance(public_key, ed25519.Ed25519PublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2

    @pytest.mark.supported(
        only_if=lambda backend: backend.ed448_supported(),
        skip_message="Requires OpenSSL with Ed448 support",
    )
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_ca_request_with_ed448(self, backend):
        private_key = ed448.Ed448PrivateKey.generate()

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, None, backend)
        )

        assert request.signature_hash_algorithm is None
        public_key = request.public_key()
        assert isinstance(public_key, ed448.Ed448PublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2

    @pytest.mark.requires_backend_interface(interface=DSABackend)
    def test_build_ca_request_with_dsa(self, backend):
        private_key = DSA_KEY_2048.private_key(backend)

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, dsa.DSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
        ]
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2

    def test_add_duplicate_extension(self):
        builder = x509.CertificateSigningRequestBuilder().add_extension(
            x509.BasicConstraints(True, 2),
            critical=True,
        )
        with pytest.raises(ValueError):
            builder.add_extension(
                x509.BasicConstraints(True, 2),
                critical=True,
            )

    def test_set_invalid_subject(self):
        builder = x509.CertificateSigningRequestBuilder()
        with pytest.raises(TypeError):
            builder.subject_name("NotAName")

    def test_add_invalid_extension_type(self):
        builder = x509.CertificateSigningRequestBuilder()

        with pytest.raises(TypeError):
            builder.add_extension(object(), False)

    def test_add_unsupported_extension(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder()
        builder = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .add_extension(DummyExtension(), False)
        )
        with pytest.raises(NotImplementedError):
            builder.sign(private_key, hashes.SHA256(), backend)

    def test_key_usage(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder()
        request = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.KeyUsage(
                    digital_signature=True,
                    content_commitment=True,
                    key_encipherment=False,
                    data_encipherment=False,
                    key_agreement=False,
                    key_cert_sign=True,
                    crl_sign=False,
                    encipher_only=False,
                    decipher_only=False,
                ),
                critical=False,
            )
            .sign(private_key, hashes.SHA256(), backend)
        )
        assert len(request.extensions) == 1
        ext = request.extensions.get_extension_for_oid(ExtensionOID.KEY_USAGE)
        assert ext.critical is False
        assert ext.value == x509.KeyUsage(
            digital_signature=True,
            content_commitment=True,
            key_encipherment=False,
            data_encipherment=False,
            key_agreement=False,
            key_cert_sign=True,
            crl_sign=False,
            encipher_only=False,
            decipher_only=False,
        )

    def test_key_usage_key_agreement_bit(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder()
        request = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.KeyUsage(
                    digital_signature=False,
                    content_commitment=False,
                    key_encipherment=False,
                    data_encipherment=False,
                    key_agreement=True,
                    key_cert_sign=True,
                    crl_sign=False,
                    encipher_only=False,
                    decipher_only=True,
                ),
                critical=False,
            )
            .sign(private_key, hashes.SHA256(), backend)
        )
        assert len(request.extensions) == 1
        ext = request.extensions.get_extension_for_oid(ExtensionOID.KEY_USAGE)
        assert ext.critical is False
        assert ext.value == x509.KeyUsage(
            digital_signature=False,
            content_commitment=False,
            key_encipherment=False,
            data_encipherment=False,
            key_agreement=True,
            key_cert_sign=True,
            crl_sign=False,
            encipher_only=False,
            decipher_only=True,
        )

    def test_add_two_extensions(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder()
        request = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [x509.DNSName(u"cryptography.io")]
                ),
                critical=False,
            )
            .add_extension(
                x509.BasicConstraints(ca=True, path_length=2), critical=True
            )
            .sign(private_key, hashes.SHA1(), backend)
        )

        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, rsa.RSAPublicKey)
        basic_constraints = request.extensions.get_extension_for_oid(
            ExtensionOID.BASIC_CONSTRAINTS
        )
        assert basic_constraints.value.ca is True
        assert basic_constraints.value.path_length == 2
        ext = request.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert list(ext.value) == [x509.DNSName(u"cryptography.io")]

    @pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
    def test_add_attributes(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        private_key = ec.generate_private_key(ec.SECP256R1(), backend)
        challenge_password = b"challenge me!"
        unstructured_name = b"no structure, for shame"
        locality = b"this shouldn't even be an X509 attribute"

        request = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name(
                    [
                        x509.NameAttribute(
                            NameOID.STATE_OR_PROVINCE_NAME, u"Texas"
                        ),
                    ]
                )
            )
            .add_attribute(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD, challenge_password
            )
            .add_attribute(
                x509.oid.AttributeOID.UNSTRUCTURED_NAME, unstructured_name
            )
            .add_attribute(x509.oid.NameOID.LOCALITY_NAME, locality)
            .sign(private_key, hashes.SHA256(), backend)
        )

        assert (
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD
            )
            == challenge_password
        )
        assert (
            request.get_attribute_for_oid(
                x509.oid.AttributeOID.UNSTRUCTURED_NAME
            )
            == unstructured_name
        )
        assert (
            request.get_attribute_for_oid(x509.oid.NameOID.LOCALITY_NAME)
            == locality
        )

    def test_add_attribute_bad_types(self, backend):
        request = x509.CertificateSigningRequestBuilder()
        with pytest.raises(TypeError):
            request.add_attribute(b"not an oid", b"val")

        with pytest.raises(TypeError):
            request.add_attribute(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD, 383
            )

    def test_duplicate_attribute(self, backend):
        request = x509.CertificateSigningRequestBuilder().add_attribute(
            x509.oid.AttributeOID.CHALLENGE_PASSWORD, b"val"
        )
        with pytest.raises(ValueError):
            request.add_attribute(
                x509.oid.AttributeOID.CHALLENGE_PASSWORD, b"val2"
            )

    def test_set_subject_twice(self):
        builder = x509.CertificateSigningRequestBuilder()
        builder = builder.subject_name(
            x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        )
        with pytest.raises(ValueError):
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )

    def test_subject_alt_names(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        san = x509.SubjectAlternativeName(
            [
                x509.DNSName(u"example.com"),
                x509.DNSName(u"*.example.com"),
                x509.RegisteredID(x509.ObjectIdentifier("1.2.3.4.5.6.7")),
                x509.DirectoryName(
                    x509.Name(
                        [
                            x509.NameAttribute(NameOID.COMMON_NAME, u"PyCA"),
                            x509.NameAttribute(
                                NameOID.ORGANIZATION_NAME,
                                u"We heart UTF8!\u2122",
                            ),
                        ]
                    )
                ),
                x509.IPAddress(ipaddress.ip_address(u"127.0.0.1")),
                x509.IPAddress(ipaddress.ip_address(u"ff::")),
                x509.OtherName(
                    type_id=x509.ObjectIdentifier("1.2.3.3.3.3"),
                    value=b"0\x03\x02\x01\x05",
                ),
                x509.RFC822Name(u"test@example.com"),
                x509.RFC822Name(u"email"),
                x509.RFC822Name(u"email@xn--eml-vla4c.com"),
                x509.UniformResourceIdentifier(
                    u"https://xn--80ato2c.cryptography"
                ),
                x509.UniformResourceIdentifier(
                    u"gopher://cryptography:70/some/path"
                ),
            ]
        )

        csr = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, u"SAN")])
            )
            .add_extension(
                san,
                critical=False,
            )
            .sign(private_key, hashes.SHA256(), backend)
        )

        assert len(csr.extensions) == 1
        ext = csr.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        )
        assert not ext.critical
        assert ext.oid == ExtensionOID.SUBJECT_ALTERNATIVE_NAME
        assert ext.value == san

    def test_invalid_asn1_othername(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        builder = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, u"SAN")])
            )
            .add_extension(
                x509.SubjectAlternativeName(
                    [
                        x509.OtherName(
                            type_id=x509.ObjectIdentifier("1.2.3.3.3.3"),
                            value=b"\x01\x02\x01\x05",
                        ),
                    ]
                ),
                critical=False,
            )
        )
        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    def test_subject_alt_name_unsupported_general_name(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)

        builder = (
            x509.CertificateSigningRequestBuilder()
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, u"SAN")])
            )
            .add_extension(
                x509.SubjectAlternativeName([FakeGeneralName("")]),
                critical=False,
            )
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA256(), backend)

    def test_extended_key_usage(self, backend):
        private_key = RSA_KEY_2048.private_key(backend)
        eku = x509.ExtendedKeyUsage(
            [
                ExtendedKeyUsageOID.CLIENT_AUTH,
                ExtendedKeyUsageOID.SERVER_AUTH,
                ExtendedKeyUsageOID.CODE_SIGNING,
            ]
        )
        builder = x509.CertificateSigningRequestBuilder()
        request = (
            builder.subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .add_extension(eku, critical=False)
            .sign(private_key, hashes.SHA256(), backend)
        )

        ext = request.extensions.get_extension_for_oid(
            ExtensionOID.EXTENDED_KEY_USAGE
        )
        assert ext.critical is False
        assert ext.value == eku

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    def test_rsa_key_too_small(self, backend):
        private_key = RSA_KEY_512.private_key(backend)
        builder = x509.CertificateSigningRequestBuilder()
        builder = builder.subject_name(
            x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        )

        with pytest.raises(ValueError):
            builder.sign(private_key, hashes.SHA512(), backend)

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_aia(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        aia = x509.AuthorityInformationAccess(
            [
                x509.AccessDescription(
                    AuthorityInformationAccessOID.OCSP,
                    x509.UniformResourceIdentifier(u"http://ocsp.domain.com"),
                ),
                x509.AccessDescription(
                    AuthorityInformationAccessOID.CA_ISSUERS,
                    x509.UniformResourceIdentifier(
                        u"http://domain.com/ca.crt"
                    ),
                ),
            ]
        )

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(aia, critical=False)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA1(), backend)

        ext = cert.extensions.get_extension_for_oid(
            ExtensionOID.AUTHORITY_INFORMATION_ACCESS
        )
        assert ext.value == aia

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_sia(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        sia = x509.SubjectInformationAccess(
            [
                x509.AccessDescription(
                    SubjectInformationAccessOID.CA_REPOSITORY,
                    x509.UniformResourceIdentifier(u"http://ca.domain.com"),
                ),
            ]
        )

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(sia, critical=False)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)

        ext = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_INFORMATION_ACCESS
        )
        assert ext.value == sia

    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_ski(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        ski = x509.SubjectKeyIdentifier.from_public_key(
            subject_private_key.public_key()
        )

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(ski, critical=False)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA1(), backend)

        ext = cert.extensions.get_extension_for_oid(
            ExtensionOID.SUBJECT_KEY_IDENTIFIER
        )
        assert ext.value == ski

    @pytest.mark.parametrize(
        "aki",
        [
            x509.AuthorityKeyIdentifier(
                b"\xc3\x9c\xf3\xfc\xd3F\x084\xbb\xceF\x7f\xa0|[\xf3\xe2\x08"
                b"\xcbY",
                None,
                None,
            ),
            x509.AuthorityKeyIdentifier(
                b"\xc3\x9c\xf3\xfc\xd3F\x084\xbb\xceF\x7f\xa0|[\xf3\xe2\x08"
                b"\xcbY",
                [
                    x509.DirectoryName(
                        x509.Name(
                            [
                                x509.NameAttribute(
                                    NameOID.ORGANIZATION_NAME, u"PyCA"
                                ),
                                x509.NameAttribute(
                                    NameOID.COMMON_NAME, u"cryptography CA"
                                ),
                            ]
                        )
                    )
                ],
                333,
            ),
            x509.AuthorityKeyIdentifier(
                None,
                [
                    x509.DirectoryName(
                        x509.Name(
                            [
                                x509.NameAttribute(
                                    NameOID.ORGANIZATION_NAME, u"PyCA"
                                ),
                                x509.NameAttribute(
                                    NameOID.COMMON_NAME, u"cryptography CA"
                                ),
                            ]
                        )
                    )
                ],
                333,
            ),
        ],
    )
    @pytest.mark.requires_backend_interface(interface=RSABackend)
    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_build_cert_with_aki(self, aki, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(aki, critical=False)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)

        ext = cert.extensions.get_extension_for_oid(
            ExtensionOID.AUTHORITY_KEY_IDENTIFIER
        )
        assert ext.value == aki

    def test_ocsp_nocheck(self, backend):
        issuer_private_key = RSA_KEY_2048.private_key(backend)
        subject_private_key = RSA_KEY_2048.private_key(backend)

        not_valid_before = datetime.datetime(2002, 1, 1, 12, 1)
        not_valid_after = datetime.datetime(2030, 12, 31, 8, 30)

        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(subject_private_key.public_key())
            .add_extension(x509.OCSPNoCheck(), critical=False)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        cert = builder.sign(issuer_private_key, hashes.SHA256(), backend)

        ext = cert.extensions.get_extension_for_oid(ExtensionOID.OCSP_NO_CHECK)
        assert isinstance(ext.value, x509.OCSPNoCheck)


@pytest.mark.requires_backend_interface(interface=DSABackend)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestDSACertificate(object):
    def test_load_dsa_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "dsa_selfsigned_ca.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA1)
        public_key = cert.public_key()
        assert isinstance(public_key, dsa.DSAPublicKey)
        num = public_key.public_numbers()
        assert num.y == int(
            "4c08bfe5f2d76649c80acf7d431f6ae2124b217abc8c9f6aca776ddfa94"
            "53b6656f13e543684cd5f6431a314377d2abfa068b7080cb8ddc065afc2"
            "dea559f0b584c97a2b235b9b69b46bc6de1aed422a6f341832618bcaae2"
            "198aba388099dafb05ff0b5efecb3b0ae169a62e1c72022af50ae68af3b"
            "033c18e6eec1f7df4692c456ccafb79cc7e08da0a5786e9816ceda651d6"
            "1b4bb7b81c2783da97cea62df67af5e85991fdc13aff10fc60e06586386"
            "b96bb78d65750f542f86951e05a6d81baadbcd35a2e5cad4119923ae6a2"
            "002091a3d17017f93c52970113cdc119970b9074ca506eac91c3dd37632"
            "5df4af6b3911ef267d26623a5a1c5df4a6d13f1c",
            16,
        )
        assert num.parameter_numbers.g == int(
            "4b7ced71dc353965ecc10d441a9a06fc24943a32d66429dd5ef44d43e67"
            "d789d99770aec32c0415dc92970880872da45fef8dd1e115a3e4801387b"
            "a6d755861f062fd3b6e9ea8e2641152339b828315b1528ee6c7b79458d2"
            "1f3db973f6fc303f9397174c2799dd2351282aa2d8842c357a73495bbaa"
            "c4932786414c55e60d73169f5761036fba29e9eebfb049f8a3b1b7cee6f"
            "3fbfa136205f130bee2cf5b9c38dc1095d4006f2e73335c07352c64130a"
            "1ab2b89f13b48f628d3cc3868beece9bb7beade9f830eacc6fa241425c0"
            "b3fcc0df416a0c89f7bf35668d765ec95cdcfbe9caff49cfc156c668c76"
            "fa6247676a6d3ac945844a083509c6a1b436baca",
            16,
        )
        assert num.parameter_numbers.p == int(
            "bfade6048e373cd4e48b677e878c8e5b08c02102ae04eb2cb5c46a523a3"
            "af1c73d16b24f34a4964781ae7e50500e21777754a670bd19a7420d6330"
            "84e5556e33ca2c0e7d547ea5f46a07a01bf8669ae3bdec042d9b2ae5e6e"
            "cf49f00ba9dac99ab6eff140d2cedf722ee62c2f9736857971444c25d0a"
            "33d2017dc36d682a1054fe2a9428dda355a851ce6e6d61e03e419fd4ca4"
            "e703313743d86caa885930f62ed5bf342d8165627681e9cc3244ba72aa2"
            "2148400a6bbe80154e855d042c9dc2a3405f1e517be9dea50562f56da93"
            "f6085f844a7e705c1f043e65751c583b80d29103e590ccb26efdaa0893d"
            "833e36468f3907cfca788a3cb790f0341c8a31bf",
            16,
        )
        assert num.parameter_numbers.q == int(
            "822ff5d234e073b901cf5941f58e1f538e71d40d", 16
        )

    def test_signature(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "dsa_selfsigned_ca.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.signature == binascii.unhexlify(
            b"302c021425c4a84a936ab311ee017d3cbd9a3c650bb3ae4a02145d30c64b4326"
            b"86bdf925716b4ed059184396bcce"
        )
        r, s = decode_dss_signature(cert.signature)
        assert r == 215618264820276283222494627481362273536404860490
        assert s == 532023851299196869156027211159466197586787351758

    def test_tbs_certificate_bytes(self, backend):
        cert = _load_cert(
            os.path.join("x509", "custom", "dsa_selfsigned_ca.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.tbs_certificate_bytes == binascii.unhexlify(
            b"3082051aa003020102020900a37352e0b2142f86300906072a8648ce3804033"
            b"067310b3009060355040613025553310e300c06035504081305546578617331"
            b"0f300d0603550407130641757374696e3121301f060355040a1318496e74657"
            b"26e6574205769646769747320507479204c7464311430120603550403130b50"
            b"79434120445341204341301e170d3134313132373035313431375a170d31343"
            b"13232373035313431375a3067310b3009060355040613025553310e300c0603"
            b"55040813055465786173310f300d0603550407130641757374696e3121301f0"
            b"60355040a1318496e7465726e6574205769646769747320507479204c746431"
            b"1430120603550403130b50794341204453412043413082033a3082022d06072"
            b"a8648ce380401308202200282010100bfade6048e373cd4e48b677e878c8e5b"
            b"08c02102ae04eb2cb5c46a523a3af1c73d16b24f34a4964781ae7e50500e217"
            b"77754a670bd19a7420d633084e5556e33ca2c0e7d547ea5f46a07a01bf8669a"
            b"e3bdec042d9b2ae5e6ecf49f00ba9dac99ab6eff140d2cedf722ee62c2f9736"
            b"857971444c25d0a33d2017dc36d682a1054fe2a9428dda355a851ce6e6d61e0"
            b"3e419fd4ca4e703313743d86caa885930f62ed5bf342d8165627681e9cc3244"
            b"ba72aa22148400a6bbe80154e855d042c9dc2a3405f1e517be9dea50562f56d"
            b"a93f6085f844a7e705c1f043e65751c583b80d29103e590ccb26efdaa0893d8"
            b"33e36468f3907cfca788a3cb790f0341c8a31bf021500822ff5d234e073b901"
            b"cf5941f58e1f538e71d40d028201004b7ced71dc353965ecc10d441a9a06fc2"
            b"4943a32d66429dd5ef44d43e67d789d99770aec32c0415dc92970880872da45"
            b"fef8dd1e115a3e4801387ba6d755861f062fd3b6e9ea8e2641152339b828315"
            b"b1528ee6c7b79458d21f3db973f6fc303f9397174c2799dd2351282aa2d8842"
            b"c357a73495bbaac4932786414c55e60d73169f5761036fba29e9eebfb049f8a"
            b"3b1b7cee6f3fbfa136205f130bee2cf5b9c38dc1095d4006f2e73335c07352c"
            b"64130a1ab2b89f13b48f628d3cc3868beece9bb7beade9f830eacc6fa241425"
            b"c0b3fcc0df416a0c89f7bf35668d765ec95cdcfbe9caff49cfc156c668c76fa"
            b"6247676a6d3ac945844a083509c6a1b436baca0382010500028201004c08bfe"
            b"5f2d76649c80acf7d431f6ae2124b217abc8c9f6aca776ddfa9453b6656f13e"
            b"543684cd5f6431a314377d2abfa068b7080cb8ddc065afc2dea559f0b584c97"
            b"a2b235b9b69b46bc6de1aed422a6f341832618bcaae2198aba388099dafb05f"
            b"f0b5efecb3b0ae169a62e1c72022af50ae68af3b033c18e6eec1f7df4692c45"
            b"6ccafb79cc7e08da0a5786e9816ceda651d61b4bb7b81c2783da97cea62df67"
            b"af5e85991fdc13aff10fc60e06586386b96bb78d65750f542f86951e05a6d81"
            b"baadbcd35a2e5cad4119923ae6a2002091a3d17017f93c52970113cdc119970"
            b"b9074ca506eac91c3dd376325df4af6b3911ef267d26623a5a1c5df4a6d13f1"
            b"ca381cc3081c9301d0603551d0e04160414a4fb887a13fcdeb303bbae9a1dec"
            b"a72f125a541b3081990603551d2304819130818e8014a4fb887a13fcdeb303b"
            b"bae9a1deca72f125a541ba16ba4693067310b3009060355040613025553310e"
            b"300c060355040813055465786173310f300d0603550407130641757374696e3"
            b"121301f060355040a1318496e7465726e657420576964676974732050747920"
            b"4c7464311430120603550403130b5079434120445341204341820900a37352e"
            b"0b2142f86300c0603551d13040530030101ff"
        )
        cert.public_key().verify(
            cert.signature,
            cert.tbs_certificate_bytes,
            cert.signature_hash_algorithm,
        )


@pytest.mark.requires_backend_interface(interface=DSABackend)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestDSACertificateRequest(object):
    @pytest.mark.parametrize(
        ("path", "loader_func"),
        [
            [
                os.path.join("x509", "requests", "dsa_sha1.pem"),
                x509.load_pem_x509_csr,
            ],
            [
                os.path.join("x509", "requests", "dsa_sha1.der"),
                x509.load_der_x509_csr,
            ],
        ],
    )
    def test_load_dsa_request(self, path, loader_func, backend):
        request = _load_cert(path, loader_func, backend)
        assert isinstance(request.signature_hash_algorithm, hashes.SHA1)
        public_key = request.public_key()
        assert isinstance(public_key, dsa.DSAPublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
        ]

    def test_signature(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "dsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.signature == binascii.unhexlify(
            b"302c021461d58dc028d0110818a7d817d74235727c4acfdf0214097b52e198e"
            b"ce95de17273f0a924df23ce9d8188"
        )

    def test_tbs_certrequest_bytes(self, backend):
        request = _load_cert(
            os.path.join("x509", "requests", "dsa_sha1.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.tbs_certrequest_bytes == binascii.unhexlify(
            b"3082021802010030573118301606035504030c0f63727970746f677261706879"
            b"2e696f310d300b060355040a0c0450794341310b300906035504061302555331"
            b"0e300c06035504080c055465786173310f300d06035504070c0641757374696e"
            b"308201b63082012b06072a8648ce3804013082011e028181008d7fadbc09e284"
            b"aafa69154cea24177004909e519f8b35d685cde5b4ecdc9583e74d370a0f88ad"
            b"a98f026f27762fb3d5da7836f986dfcdb3589e5b925bea114defc03ef81dae30"
            b"c24bbc6df3d588e93427bba64203d4a5b1687b2b5e3b643d4c614976f89f95a3"
            b"8d3e4c89065fba97514c22c50adbbf289163a74b54859b35b7021500835de56b"
            b"d07cf7f82e2032fe78949aed117aa2ef0281801f717b5a07782fc2e4e68e311f"
            b"ea91a54edd36b86ac634d14f05a68a97eae9d2ef31fb1ef3de42c3d100df9ca6"
            b"4f5bdc2aec7bfdfb474cf831fea05853b5e059f2d24980a0ac463f1e818af352"
            b"3e3cb79a39d45fa92731897752842469cf8540b01491024eaafbce6018e8a1f4"
            b"658c343f4ba7c0b21e5376a21f4beb8491961e038184000281800713f07641f6"
            b"369bb5a9545274a2d4c01998367fb371bb9e13436363672ed68f82174c2de05c"
            b"8e839bc6de568dd50ba28d8d9d8719423aaec5557df10d773ab22d6d65cbb878"
            b"04a697bc8fd965b952f9f7e850edf13c8acdb5d753b6d10e59e0b5732e3c82ba"
            b"fa140342bc4a3bba16bd0681c8a6a2dbbb7efe6ce2b8463b170ba000"
        )
        request.public_key().verify(
            request.signature,
            request.tbs_certrequest_bytes,
            request.signature_hash_algorithm,
        )


@pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestECDSACertificate(object):
    def test_load_ecdsa_cert(self, backend):
        _skip_curve_unsupported(backend, ec.SECP384R1())
        cert = _load_cert(
            os.path.join("x509", "ecdsa_root.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert isinstance(cert.signature_hash_algorithm, hashes.SHA384)
        public_key = cert.public_key()
        assert isinstance(public_key, ec.EllipticCurvePublicKey)
        num = public_key.public_numbers()
        assert num.x == int(
            "dda7d9bb8ab80bfb0b7f21d2f0bebe73f3335d1abc34eadec69bbcd095f"
            "6f0ccd00bba615b51467e9e2d9fee8e630c17",
            16,
        )
        assert num.y == int(
            "ec0770f5cf842e40839ce83f416d3badd3a4145936789d0343ee10136c7"
            "2deae88a7a16bb543ce67dc23ff031ca3e23e",
            16,
        )
        assert isinstance(num.curve, ec.SECP384R1)

    def test_signature(self, backend):
        cert = _load_cert(
            os.path.join("x509", "ecdsa_root.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.signature == binascii.unhexlify(
            b"3065023100adbcf26c3f124ad12d39c30a099773f488368c8827bbe6888d5085"
            b"a763f99e32de66930ff1ccb1098fdd6cabfa6b7fa0023039665bc2648db89e50"
            b"dca8d549a2edc7dcd1497f1701b8c8868f4e8c882ba89aa98ac5d100bdf854e2"
            b"9ae55b7cb32717"
        )
        r, s = decode_dss_signature(cert.signature)
        assert r == int(
            "adbcf26c3f124ad12d39c30a099773f488368c8827bbe6888d5085a763f99e32"
            "de66930ff1ccb1098fdd6cabfa6b7fa0",
            16,
        )
        assert s == int(
            "39665bc2648db89e50dca8d549a2edc7dcd1497f1701b8c8868f4e8c882ba89a"
            "a98ac5d100bdf854e29ae55b7cb32717",
            16,
        )

    def test_tbs_certificate_bytes(self, backend):
        _skip_curve_unsupported(backend, ec.SECP384R1())
        cert = _load_cert(
            os.path.join("x509", "ecdsa_root.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert cert.tbs_certificate_bytes == binascii.unhexlify(
            b"308201c5a0030201020210055556bcf25ea43535c3a40fd5ab4572300a06082"
            b"a8648ce3d0403033061310b300906035504061302555331153013060355040a"
            b"130c446967694365727420496e6331193017060355040b13107777772e64696"
            b"769636572742e636f6d3120301e06035504031317446967694365727420476c"
            b"6f62616c20526f6f74204733301e170d3133303830313132303030305a170d3"
            b"338303131353132303030305a3061310b300906035504061302555331153013"
            b"060355040a130c446967694365727420496e6331193017060355040b1310777"
            b"7772e64696769636572742e636f6d3120301e06035504031317446967694365"
            b"727420476c6f62616c20526f6f742047333076301006072a8648ce3d0201060"
            b"52b8104002203620004dda7d9bb8ab80bfb0b7f21d2f0bebe73f3335d1abc34"
            b"eadec69bbcd095f6f0ccd00bba615b51467e9e2d9fee8e630c17ec0770f5cf8"
            b"42e40839ce83f416d3badd3a4145936789d0343ee10136c72deae88a7a16bb5"
            b"43ce67dc23ff031ca3e23ea3423040300f0603551d130101ff040530030101f"
            b"f300e0603551d0f0101ff040403020186301d0603551d0e04160414b3db48a4"
            b"f9a1c5d8ae3641cc1163696229bc4bc6"
        )
        cert.public_key().verify(
            cert.signature,
            cert.tbs_certificate_bytes,
            ec.ECDSA(cert.signature_hash_algorithm),
        )

    def test_load_ecdsa_no_named_curve(self, backend):
        _skip_curve_unsupported(backend, ec.SECP256R1())
        cert = _load_cert(
            os.path.join("x509", "custom", "ec_no_named_curve.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        with pytest.raises(NotImplementedError):
            cert.public_key()


@pytest.mark.requires_backend_interface(interface=X509Backend)
@pytest.mark.requires_backend_interface(interface=EllipticCurveBackend)
class TestECDSACertificateRequest(object):
    @pytest.mark.parametrize(
        ("path", "loader_func"),
        [
            [
                os.path.join("x509", "requests", "ec_sha256.pem"),
                x509.load_pem_x509_csr,
            ],
            [
                os.path.join("x509", "requests", "ec_sha256.der"),
                x509.load_der_x509_csr,
            ],
        ],
    )
    def test_load_ecdsa_certificate_request(self, path, loader_func, backend):
        _skip_curve_unsupported(backend, ec.SECP384R1())
        request = _load_cert(path, loader_func, backend)
        assert isinstance(request.signature_hash_algorithm, hashes.SHA256)
        public_key = request.public_key()
        assert isinstance(public_key, ec.EllipticCurvePublicKey)
        subject = request.subject
        assert isinstance(subject, x509.Name)
        assert list(subject) == [
            x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
            x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"Texas"),
            x509.NameAttribute(NameOID.LOCALITY_NAME, u"Austin"),
        ]

    def test_signature(self, backend):
        _skip_curve_unsupported(backend, ec.SECP384R1())
        request = _load_cert(
            os.path.join("x509", "requests", "ec_sha256.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.signature == binascii.unhexlify(
            b"306502302c1a9f7de8c1787332d2307a886b476a59f172b9b0e250262f3238b1"
            b"b45ee112bb6eb35b0fb56a123b9296eb212dffc302310094cf440c95c52827d5"
            b"56ae6d76500e3008255d47c29f7ee782ed7558e51bfd76aa45df6d999ed5c463"
            b"347fe2382d1751"
        )

    def test_tbs_certrequest_bytes(self, backend):
        _skip_curve_unsupported(backend, ec.SECP384R1())
        request = _load_cert(
            os.path.join("x509", "requests", "ec_sha256.pem"),
            x509.load_pem_x509_csr,
            backend,
        )
        assert request.tbs_certrequest_bytes == binascii.unhexlify(
            b"3081d602010030573118301606035504030c0f63727970746f6772617068792"
            b"e696f310d300b060355040a0c0450794341310b300906035504061302555331"
            b"0e300c06035504080c055465786173310f300d06035504070c0641757374696"
            b"e3076301006072a8648ce3d020106052b8104002203620004de19b514c0b3c3"
            b"ae9b398ea3e26b5e816bdcf9102cad8f12fe02f9e4c9248724b39297ed7582e"
            b"04d8b32a551038d09086803a6d3fb91a1a1167ec02158b00efad39c9396462f"
            b"accff0ffaf7155812909d3726bd59fde001cff4bb9b2f5af8cbaa000"
        )
        request.public_key().verify(
            request.signature,
            request.tbs_certrequest_bytes,
            ec.ECDSA(request.signature_hash_algorithm),
        )


@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestOtherCertificate(object):
    def test_unsupported_subject_public_key_info(self, backend):
        cert = _load_cert(
            os.path.join(
                "x509", "custom", "unsupported_subject_public_key_info.pem"
            ),
            x509.load_pem_x509_certificate,
            backend,
        )

        with pytest.raises(ValueError):
            cert.public_key()

    def test_bad_time_in_validity(self, backend):
        cert = _load_cert(
            os.path.join("x509", "badasn1time.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )

        with pytest.raises(ValueError, match="19020701025736Z"):
            cert.not_valid_after


class TestNameAttribute(object):
    EXPECTED_TYPES = [
        (NameOID.COMMON_NAME, _ASN1Type.UTF8String),
        (NameOID.COUNTRY_NAME, _ASN1Type.PrintableString),
        (NameOID.LOCALITY_NAME, _ASN1Type.UTF8String),
        (NameOID.STATE_OR_PROVINCE_NAME, _ASN1Type.UTF8String),
        (NameOID.STREET_ADDRESS, _ASN1Type.UTF8String),
        (NameOID.ORGANIZATION_NAME, _ASN1Type.UTF8String),
        (NameOID.ORGANIZATIONAL_UNIT_NAME, _ASN1Type.UTF8String),
        (NameOID.SERIAL_NUMBER, _ASN1Type.PrintableString),
        (NameOID.SURNAME, _ASN1Type.UTF8String),
        (NameOID.GIVEN_NAME, _ASN1Type.UTF8String),
        (NameOID.TITLE, _ASN1Type.UTF8String),
        (NameOID.GENERATION_QUALIFIER, _ASN1Type.UTF8String),
        (NameOID.X500_UNIQUE_IDENTIFIER, _ASN1Type.UTF8String),
        (NameOID.DN_QUALIFIER, _ASN1Type.PrintableString),
        (NameOID.PSEUDONYM, _ASN1Type.UTF8String),
        (NameOID.USER_ID, _ASN1Type.UTF8String),
        (NameOID.DOMAIN_COMPONENT, _ASN1Type.IA5String),
        (NameOID.EMAIL_ADDRESS, _ASN1Type.IA5String),
        (NameOID.JURISDICTION_COUNTRY_NAME, _ASN1Type.PrintableString),
        (NameOID.JURISDICTION_LOCALITY_NAME, _ASN1Type.UTF8String),
        (NameOID.JURISDICTION_STATE_OR_PROVINCE_NAME, _ASN1Type.UTF8String),
        (NameOID.BUSINESS_CATEGORY, _ASN1Type.UTF8String),
        (NameOID.POSTAL_ADDRESS, _ASN1Type.UTF8String),
        (NameOID.POSTAL_CODE, _ASN1Type.UTF8String),
    ]

    def test_default_types(self):
        for oid, asn1_type in TestNameAttribute.EXPECTED_TYPES:
            na = x509.NameAttribute(oid, u"US")
            assert na._type == asn1_type

    def test_alternate_type(self):
        na2 = x509.NameAttribute(
            NameOID.COMMON_NAME, u"common", _ASN1Type.IA5String
        )
        assert na2._type == _ASN1Type.IA5String

    def test_init_bad_oid(self):
        with pytest.raises(TypeError):
            x509.NameAttribute(None, u"value")

    def test_init_bad_value(self):
        with pytest.raises(TypeError):
            x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), b"bytes")

    def test_init_none_value(self):
        with pytest.raises(TypeError):
            x509.NameAttribute(NameOID.ORGANIZATION_NAME, None)

    def test_init_bad_country_code_value(self):
        with pytest.raises(ValueError):
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"United States")

        # unicode string of length 2, but > 2 bytes
        with pytest.raises(ValueError):
            x509.NameAttribute(NameOID.COUNTRY_NAME, u"\U0001F37A\U0001F37A")

    def test_invalid_type(self):
        with pytest.raises(TypeError):
            x509.NameAttribute(NameOID.COMMON_NAME, u"common", "notanenum")

    def test_eq(self):
        assert x509.NameAttribute(
            x509.ObjectIdentifier("2.999.1"), u"value"
        ) == x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value")

    def test_ne(self):
        assert x509.NameAttribute(
            x509.ObjectIdentifier("2.5.4.3"), u"value"
        ) != x509.NameAttribute(x509.ObjectIdentifier("2.5.4.5"), u"value")
        assert x509.NameAttribute(
            x509.ObjectIdentifier("2.999.1"), u"value"
        ) != x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value2")
        assert (
            x509.NameAttribute(x509.ObjectIdentifier("2.999.2"), u"value")
            != object()
        )

    def test_repr(self):
        na = x509.NameAttribute(x509.ObjectIdentifier("2.5.4.3"), u"value")
        if not six.PY2:
            assert repr(na) == (
                "<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.3, name=commo"
                "nName)>, value='value')>"
            )
        else:
            assert repr(na) == (
                "<NameAttribute(oid=<ObjectIdentifier(oid=2.5.4.3, name=commo"
                "nName)>, value=u'value')>"
            )

    def test_distinugished_name(self):
        # Escaping
        na = x509.NameAttribute(NameOID.COMMON_NAME, u'James "Jim" Smith, III')
        assert na.rfc4514_string() == r"CN=James \"Jim\" Smith\, III"
        na = x509.NameAttribute(NameOID.USER_ID, u"# escape+,;\0this ")
        assert na.rfc4514_string() == r"UID=\# escape\+\,\;\00this\ "

        # Nonstandard attribute OID
        na = x509.NameAttribute(NameOID.EMAIL_ADDRESS, u"somebody@example.com")
        assert (
            na.rfc4514_string() == "1.2.840.113549.1.9.1=somebody@example.com"
        )

    def test_empty_value(self):
        na = x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u"")
        assert na.rfc4514_string() == r"ST="


class TestRelativeDistinguishedName(object):
    def test_init_empty(self):
        with pytest.raises(ValueError):
            x509.RelativeDistinguishedName([])

    def test_init_not_nameattribute(self):
        with pytest.raises(TypeError):
            x509.RelativeDistinguishedName(["not-a-NameAttribute"])

    def test_init_duplicate_attribute(self):
        with pytest.raises(ValueError):
            x509.RelativeDistinguishedName(
                [
                    x509.NameAttribute(
                        x509.ObjectIdentifier("2.999.1"), u"val1"
                    ),
                    x509.NameAttribute(
                        x509.ObjectIdentifier("2.999.1"), u"val1"
                    ),
                ]
            )

    def test_hash(self):
        rdn1 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value2"
                ),
            ]
        )
        rdn2 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value2"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
            ]
        )
        rdn3 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value3"
                ),
            ]
        )
        assert hash(rdn1) == hash(rdn2)
        assert hash(rdn1) != hash(rdn3)

    def test_eq(self):
        rdn1 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value2"
                ),
            ]
        )
        rdn2 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value2"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
            ]
        )
        assert rdn1 == rdn2

    def test_ne(self):
        rdn1 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value2"
                ),
            ]
        )
        rdn2 = x509.RelativeDistinguishedName(
            [
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.1"), u"value1"
                ),
                x509.NameAttribute(
                    x509.ObjectIdentifier("2.999.2"), u"value3"
                ),
            ]
        )
        assert rdn1 != rdn2
        assert rdn1 != object()

    def test_iter_input(self):
        # Order must be preserved too
        attrs = [
            x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1"),
            x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value2"),
            x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value3"),
        ]
        rdn = x509.RelativeDistinguishedName(iter(attrs))
        assert list(rdn) == attrs
        assert list(rdn) == attrs

    def test_get_attributes_for_oid(self):
        oid = x509.ObjectIdentifier("2.999.1")
        attr = x509.NameAttribute(oid, u"value1")
        rdn = x509.RelativeDistinguishedName([attr])
        assert rdn.get_attributes_for_oid(oid) == [attr]
        assert rdn.get_attributes_for_oid(x509.ObjectIdentifier("1.2.3")) == []


class TestObjectIdentifier(object):
    def test_eq(self):
        oid1 = x509.ObjectIdentifier("2.999.1")
        oid2 = x509.ObjectIdentifier("2.999.1")
        assert oid1 == oid2

    def test_ne(self):
        oid1 = x509.ObjectIdentifier("2.999.1")
        assert oid1 != x509.ObjectIdentifier("2.999.2")
        assert oid1 != object()

    def test_repr(self):
        oid = x509.ObjectIdentifier("2.5.4.3")
        assert repr(oid) == "<ObjectIdentifier(oid=2.5.4.3, name=commonName)>"
        oid = x509.ObjectIdentifier("2.999.1")
        assert repr(oid) == "<ObjectIdentifier(oid=2.999.1, name=Unknown OID)>"

    def test_name_property(self):
        oid = x509.ObjectIdentifier("2.5.4.3")
        assert oid._name == "commonName"
        oid = x509.ObjectIdentifier("2.999.1")
        assert oid._name == "Unknown OID"

    def test_too_short(self):
        with pytest.raises(ValueError):
            x509.ObjectIdentifier("1")

    def test_invalid_input(self):
        with pytest.raises(ValueError):
            x509.ObjectIdentifier("notavalidform")

    def test_invalid_node1(self):
        with pytest.raises(ValueError):
            x509.ObjectIdentifier("7.1.37")

    def test_invalid_node2(self):
        with pytest.raises(ValueError):
            x509.ObjectIdentifier("1.50.200")

    def test_valid(self):
        x509.ObjectIdentifier("0.35.200")
        x509.ObjectIdentifier("1.39.999")
        x509.ObjectIdentifier("2.5.29.3")
        x509.ObjectIdentifier("2.999.37.5.22.8")
        x509.ObjectIdentifier("2.25.305821105408246119474742976030998643995")


class TestName(object):
    def test_eq(self):
        ava1 = x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1")
        ava2 = x509.NameAttribute(x509.ObjectIdentifier("2.999.2"), u"value2")
        name1 = x509.Name([ava1, ava2])
        name2 = x509.Name(
            [
                x509.RelativeDistinguishedName([ava1]),
                x509.RelativeDistinguishedName([ava2]),
            ]
        )
        name3 = x509.Name([x509.RelativeDistinguishedName([ava1, ava2])])
        name4 = x509.Name([x509.RelativeDistinguishedName([ava2, ava1])])
        assert name1 == name2
        assert name3 == name4

    def test_ne(self):
        ava1 = x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1")
        ava2 = x509.NameAttribute(x509.ObjectIdentifier("2.999.2"), u"value2")
        name1 = x509.Name([ava1, ava2])
        name2 = x509.Name([ava2, ava1])
        name3 = x509.Name([x509.RelativeDistinguishedName([ava1, ava2])])
        assert name1 != name2
        assert name1 != name3
        assert name1 != object()

    def test_hash(self):
        ava1 = x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1")
        ava2 = x509.NameAttribute(x509.ObjectIdentifier("2.999.2"), u"value2")
        name1 = x509.Name([ava1, ava2])
        name2 = x509.Name(
            [
                x509.RelativeDistinguishedName([ava1]),
                x509.RelativeDistinguishedName([ava2]),
            ]
        )
        name3 = x509.Name([ava2, ava1])
        name4 = x509.Name([x509.RelativeDistinguishedName([ava1, ava2])])
        name5 = x509.Name([x509.RelativeDistinguishedName([ava2, ava1])])
        assert hash(name1) == hash(name2)
        assert hash(name1) != hash(name3)
        assert hash(name1) != hash(name4)
        assert hash(name4) == hash(name5)

    def test_iter_input(self):
        attrs = [
            x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1")
        ]
        name = x509.Name(iter(attrs))
        assert list(name) == attrs
        assert list(name) == attrs

    def test_rdns(self):
        rdn1 = x509.NameAttribute(x509.ObjectIdentifier("2.999.1"), u"value1")
        rdn2 = x509.NameAttribute(x509.ObjectIdentifier("2.999.2"), u"value2")
        name1 = x509.Name([rdn1, rdn2])
        assert name1.rdns == [
            x509.RelativeDistinguishedName([rdn1]),
            x509.RelativeDistinguishedName([rdn2]),
        ]
        name2 = x509.Name([x509.RelativeDistinguishedName([rdn1, rdn2])])
        assert name2.rdns == [x509.RelativeDistinguishedName([rdn1, rdn2])]

    @pytest.mark.parametrize(
        ("common_name", "org_name", "expected_repr"),
        [
            (
                u"cryptography.io",
                u"PyCA",
                "<Name(CN=cryptography.io,O=PyCA)>",
            ),
            (
                u"Certificación",
                u"Certificación",
                "<Name(CN=Certificación,O=Certificación)>",
            ),
        ],
    )
    def test_repr(self, common_name, org_name, expected_repr):
        name = x509.Name(
            [
                x509.NameAttribute(NameOID.COMMON_NAME, common_name),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, org_name),
            ]
        )

        assert repr(name) == expected_repr

    def test_rfc4514_string(self):
        n = x509.Name(
            [
                x509.RelativeDistinguishedName(
                    [x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"net")]
                ),
                x509.RelativeDistinguishedName(
                    [x509.NameAttribute(NameOID.DOMAIN_COMPONENT, u"example")]
                ),
                x509.RelativeDistinguishedName(
                    [
                        x509.NameAttribute(
                            NameOID.ORGANIZATIONAL_UNIT_NAME, u"Sales"
                        ),
                        x509.NameAttribute(NameOID.COMMON_NAME, u"J.  Smith"),
                    ]
                ),
            ]
        )
        assert n.rfc4514_string() == "OU=Sales+CN=J.  Smith,DC=example,DC=net"

    def test_rfc4514_string_empty_values(self):
        n = x509.Name(
            [
                x509.NameAttribute(NameOID.COUNTRY_NAME, u"US"),
                x509.NameAttribute(NameOID.STATE_OR_PROVINCE_NAME, u""),
                x509.NameAttribute(NameOID.LOCALITY_NAME, u""),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
                x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
            ]
        )
        assert n.rfc4514_string() == "CN=cryptography.io,O=PyCA,L=,ST=,C=US"

    def test_not_nameattribute(self):
        with pytest.raises(TypeError):
            x509.Name(["not-a-NameAttribute"])

    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_bytes(self, backend):
        name = x509.Name(
            [
                x509.NameAttribute(NameOID.COMMON_NAME, u"cryptography.io"),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            ]
        )
        assert name.public_bytes(backend) == binascii.unhexlify(
            b"30293118301606035504030c0f63727970746f6772617068792e696f310d300"
            b"b060355040a0c0450794341"
        )

    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_bmpstring_bytes(self, backend):
        # For this test we need an odd length string. BMPString is UCS-2
        # encoded so it will always be even length and OpenSSL will error if
        # you pass an odd length string without encoding it properly first.
        name = x509.Name(
            [
                x509.NameAttribute(
                    NameOID.COMMON_NAME,
                    u"cryptography.io",
                    _ASN1Type.BMPString,
                ),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            ]
        )
        assert name.public_bytes(backend) == binascii.unhexlify(
            b"30383127302506035504031e1e00630072007900700074006f00670072006100"
            b"7000680079002e0069006f310d300b060355040a0c0450794341"
        )

    @pytest.mark.requires_backend_interface(interface=X509Backend)
    def test_universalstring_bytes(self, backend):
        # UniversalString is UCS-4
        name = x509.Name(
            [
                x509.NameAttribute(
                    NameOID.COMMON_NAME,
                    u"cryptography.io",
                    _ASN1Type.UniversalString,
                ),
                x509.NameAttribute(NameOID.ORGANIZATION_NAME, u"PyCA"),
            ]
        )
        assert name.public_bytes(backend) == binascii.unhexlify(
            b"30563145304306035504031c3c00000063000000720000007900000070000000"
            b"740000006f000000670000007200000061000000700000006800000079000000"
            b"2e000000690000006f310d300b060355040a0c0450794341"
        )


@pytest.mark.supported(
    only_if=lambda backend: backend.ed25519_supported(),
    skip_message="Requires OpenSSL with Ed25519 support",
)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestEd25519Certificate(object):
    def test_load_pem_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "ed25519", "root-ed25519.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        # self-signed, so this will work
        cert.public_key().verify(cert.signature, cert.tbs_certificate_bytes)
        assert isinstance(cert, x509.Certificate)
        assert cert.serial_number == 9579446940964433301
        assert cert.signature_hash_algorithm is None
        assert cert.signature_algorithm_oid == SignatureAlgorithmOID.ED25519

    def test_deepcopy(self, backend):
        cert = _load_cert(
            os.path.join("x509", "ed25519", "root-ed25519.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        assert copy.deepcopy(cert) is cert


@pytest.mark.supported(
    only_if=lambda backend: backend.ed448_supported(),
    skip_message="Requires OpenSSL with Ed448 support",
)
@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestEd448Certificate(object):
    def test_load_pem_cert(self, backend):
        cert = _load_cert(
            os.path.join("x509", "ed448", "root-ed448.pem"),
            x509.load_pem_x509_certificate,
            backend,
        )
        # self-signed, so this will work
        cert.public_key().verify(cert.signature, cert.tbs_certificate_bytes)
        assert isinstance(cert, x509.Certificate)
        assert cert.serial_number == 448
        assert cert.signature_hash_algorithm is None
        assert cert.signature_algorithm_oid == SignatureAlgorithmOID.ED448


@pytest.mark.requires_backend_interface(interface=X509Backend)
class TestSignatureRejection(object):
    """Test if signing rejects DH keys properly."""

    def load_key(self, backend):
        vector = load_vectors_from_file(
            os.path.join("asymmetric", "DH", "rfc3526.txt"),
            load_nist_vectors,
        )[1]
        p = int_from_bytes(binascii.unhexlify(vector["p"]), "big")
        params = dh.DHParameterNumbers(p, int(vector["g"]))
        param = params.parameters(backend)
        return param.generate_private_key()

    def test_crt_signing_check(self, backend):
        issuer_private_key = self.load_key(backend)
        public_key = RSA_KEY_2048.private_key(backend).public_key()
        not_valid_before = datetime.datetime(2020, 1, 1, 1, 1)
        not_valid_after = datetime.datetime(2050, 12, 31, 8, 30)
        builder = (
            x509.CertificateBuilder()
            .serial_number(777)
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .subject_name(
                x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
            )
            .public_key(public_key)
            .not_valid_before(not_valid_before)
            .not_valid_after(not_valid_after)
        )

        with pytest.raises(TypeError):
            builder.sign(issuer_private_key, hashes.SHA256(), backend)

    def test_csr_signing_check(self, backend):
        private_key = self.load_key(backend)
        builder = x509.CertificateSigningRequestBuilder().subject_name(
            x509.Name([x509.NameAttribute(NameOID.COUNTRY_NAME, u"US")])
        )

        with pytest.raises(TypeError):
            builder.sign(private_key, hashes.SHA256(), backend)

    def test_crl_signing_check(self, backend):
        private_key = self.load_key(backend)
        last_time = datetime.datetime.utcnow().replace(microsecond=0)
        next_time = last_time
        builder = (
            x509.CertificateRevocationListBuilder()
            .issuer_name(
                x509.Name([x509.NameAttribute(NameOID.COMMON_NAME, u"CA")])
            )
            .last_update(last_time)
            .next_update(next_time)
        )

        with pytest.raises(TypeError):
            builder.sign(private_key, hashes.SHA256(), backend)


def test_random_serial_number(monkeypatch):
    sample_data = os.urandom(20)

    def notrandom(size):
        assert size == len(sample_data)
        return sample_data

    monkeypatch.setattr(os, "urandom", notrandom)

    serial_number = x509.random_serial_number()

    assert serial_number == utils.int_from_bytes(sample_data, "big") >> 1
    assert serial_number.bit_length() < 160