Add RSAPrivateKey.generate
diff --git a/cryptography/hazmat/primitives/asymmetric/rsa.py b/cryptography/hazmat/primitives/asymmetric/rsa.py
index 1b33eaa..60c5c80 100644
--- a/cryptography/hazmat/primitives/asymmetric/rsa.py
+++ b/cryptography/hazmat/primitives/asymmetric/rsa.py
@@ -109,6 +109,10 @@
self._public_exponent = public_exponent
self._modulus = modulus
+ @classmethod
+ def generate(self, public_exponent, key_size, backend):
+ return backend.generate_rsa_private_key(public_exponent, key_size)
+
@property
def key_size(self):
return _bit_length(self.modulus)
diff --git a/docs/hazmat/primitives/rsa.rst b/docs/hazmat/primitives/rsa.rst
index 7c6356c..a19ada3 100644
--- a/docs/hazmat/primitives/rsa.rst
+++ b/docs/hazmat/primitives/rsa.rst
@@ -13,9 +13,10 @@
An RSA private key is required for decryption and signing of messages.
- Normally you do not need to directly construct private keys because you'll
- be loading them from a file or generating them automatically.
-
+ You should use
+ :meth:`~cryptography.hazmat.primitives.asymmetric.rsa.RSAPrivateKey.generate`
+ to generate new keys.
+
.. warning::
This method only checks a limited set of properties of its arguments.
Using an RSA that you do not trust or with incorrect parameters may
@@ -23,6 +24,7 @@
recommend that you only ever load private keys that were generated with
software you trust.
+
This class conforms to the
:class:`~cryptography.hazmat.primitives.interfaces.RSAPrivateKey`
interface.
@@ -33,6 +35,22 @@
`private_exponent`, `public_exponent` or `modulus` do
not match the bounds specified in `RFC 3447`_.
+ .. classmethod:: generate(public_exponent, key_size, backend)
+
+ Generate a new ``RSAPrivateKey`` instance using ``backend``.
+
+ :param int public_exponent: The public exponent of the new key.
+ Usually one of the small Fermat primes 3, 5, 17, 257, 65537. If in
+ doubt you should `use 65537`_.
+ :param int key_size: The length of the modulus in bits. For keys
+ generated in 2014 this should be `at least 2048`_. (See page 41.)
+ Must be at least 512. Some backends may have additional
+ limitations.
+ :param backend: A
+ :class:`~cryptography.hazmat.backends.interfaces.RSABackend`
+ provider.
+ :return: A new instance of ``RSAPrivateKey``.
+
.. class:: RSAPublicKey(public_exponent, modulus)
.. versionadded:: 0.2
@@ -56,3 +74,5 @@
.. _`RSA`: https://en.wikipedia.org/wiki/RSA_(cryptosystem)
.. _`public-key`: https://en.wikipedia.org/wiki/Public-key_cryptography
.. _`RFC 3447`: https://tools.ietf.org/html/rfc3447
+.. _`use 65537`: http://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.html
+.. _`at least 2048`: http://www.ecrypt.eu.org/documents/D.SPA.20.pdf
diff --git a/tests/hazmat/primitives/test_rsa.py b/tests/hazmat/primitives/test_rsa.py
index fdd55e7..0e930e4 100644
--- a/tests/hazmat/primitives/test_rsa.py
+++ b/tests/hazmat/primitives/test_rsa.py
@@ -49,26 +49,32 @@
)
)
def test_generate_rsa_keys(self, backend, public_exponent, key_size):
- skey = backend.generate_rsa_private_key(public_exponent, key_size)
+ skey = rsa.RSAPrivateKey.generate(public_exponent, key_size, backend)
_check_rsa_private_key(skey)
assert skey.key_size == key_size
assert skey.public_exponent == public_exponent
def test_generate_bad_rsa_key(self, backend):
with pytest.raises(ValueError):
- backend.generate_rsa_private_key(public_exponent=1, key_size=2048)
+ rsa.RSAPrivateKey.generate(public_exponent=1,
+ key_size=2048,
+ backend=backend)
with pytest.raises(ValueError):
- backend.generate_rsa_private_key(public_exponent=4, key_size=2048)
+ rsa.RSAPrivateKey.generate(public_exponent=4,
+ key_size=2048,
+ backend=backend)
def test_cant_generate_insecure_tiny_key(self, backend):
with pytest.raises(ValueError):
- backend.generate_rsa_private_key(public_exponent=65537,
- key_size=511)
+ rsa.RSAPrivateKey.generate(public_exponent=65537,
+ key_size=511,
+ backend=backend)
with pytest.raises(ValueError):
- backend.generate_rsa_private_key(public_exponent=65537,
- key_size=256)
+ rsa.RSAPrivateKey.generate(public_exponent=65537,
+ key_size=256,
+ backend=backend)
@pytest.mark.parametrize(
"pkcs1_example",