Added test cases for NIST P-384 and 521. Fixed handling of key sizes which aren't divisibly by 8
diff --git a/src/cryptography/hazmat/primitives/serialization.py b/src/cryptography/hazmat/primitives/serialization.py
index b95ac1c..dad419f 100644
--- a/src/cryptography/hazmat/primitives/serialization.py
+++ b/src/cryptography/hazmat/primitives/serialization.py
@@ -102,16 +102,18 @@
elif curve_name == b"nistp521":
curve = ec.SECP521R1()
- if len(data) != 1 + 2 * (curve.key_size // 8):
- raise ValueError("Malformed key bytes")
-
if six.indexbytes(data, 0) != 4:
raise NotImplementedError(
"Compressed elliptic curve points are not supported"
)
- x = _int_from_bytes(data[1:1 + curve.key_size // 8], byteorder='big')
- y = _int_from_bytes(data[1 + curve.key_size // 8:], byteorder='big')
+ # key_size is in bits, and sometimes it's not evenly divisible by 8, so we
+ # add 7 to round up the number of bytes.
+ if len(data) != 1 + 2 * ((curve.key_size + 7) // 8):
+ raise ValueError("Malformed key bytes")
+
+ x = _int_from_bytes(data[1:1 + (curve.key_size + 7) // 8], byteorder='big')
+ y = _int_from_bytes(data[1 + (curve.key_size + 7) // 8:], byteorder='big')
return ec.EllipticCurvePublicNumbers(x, y, curve).public_key(backend)
diff --git a/tests/hazmat/primitives/test_serialization.py b/tests/hazmat/primitives/test_serialization.py
index 2434ee4..fdd88a8 100644
--- a/tests/hazmat/primitives/test_serialization.py
+++ b/tests/hazmat/primitives/test_serialization.py
@@ -812,6 +812,55 @@
expected_x, expected_y, ec.SECP256R1()
)
+ def test_load_ssh_public_key_ecdsa_nist_p384(self, backend):
+ _skip_curve_unsupported(backend, ec.SECP384R1())
+ ssh_key = (
+ b"ecdsa-sha2-nistp384 AAAAE2VjZHNhLXNoYTItbmlzdHAzODQAAAAIbmlzdHAz"
+ b"ODQAAABhBMzucOm9wbwg4iMr5QL0ya0XNQGXpw4wM5f12E3tWhdcrzyGHyel71t1"
+ b"4bvF9JZ2/WIuSxUr33XDl8jYo+lMQ5N7Vanc7f7i3AR1YydatL3wQfZStQ1I3rBa"
+ b"qQtRSEU8Tg== root@cloud-server-01"
+ )
+ key = load_ssh_public_key(ssh_key, backend)
+
+ expected_x = int(
+ "31541830871345183397582554827482786756220448716666815789487537666"
+ "592636882822352575507883817901562613492450642523901", 10
+ )
+ expected_y = int(
+ "15111413269431823234030344298767984698884955023183354737123929430"
+ "995703524272335782455051101616329050844273733614670", 10
+ )
+
+ assert key.public_numbers() == ec.EllipticCurvePublicNumbers(
+ expected_x, expected_y, ec.SECP384R1()
+ )
+
+ def test_load_ssh_public_key_ecdsa_nist_p521(self, backend):
+ _skip_curve_unsupported(backend, ec.SECP521R1())
+ ssh_key = (
+ b"ecdsa-sha2-nistp521 AAAAE2VjZHNhLXNoYTItbmlzdHA1MjEAAAAIbmlzdHA1"
+ b"MjEAAACFBAGTrRhMSEgF6Ni+PXNz+5fjS4lw3ypUILVVQ0Av+0hQxOx+MyozELon"
+ b"I8NKbrbBjijEs1GuImsmkTmWsMXS1j2A7wB4Kseh7W9KA9IZJ1+TMrzWUEwvOOXi"
+ b"wT23pbaWWXG4NaM7vssWfZBnvz3S174TCXnJ+DSccvWBFnKP0KchzLKxbg== "
+ b"root@cloud-server-01"
+ )
+ key = load_ssh_public_key(ssh_key, backend)
+
+ expected_x = int(
+ "54124123120178189598842622575230904027376313369742467279346415219"
+ "77809037378785192537810367028427387173980786968395921877911964629"
+ "142163122798974160187785455", 10
+ )
+ expected_y = int(
+ "16111775122845033200938694062381820957441843014849125660011303579"
+ "15284560361402515564433711416776946492019498546572162801954089916"
+ "006665939539407104638103918", 10
+ )
+
+ assert key.public_numbers() == ec.EllipticCurvePublicNumbers(
+ expected_x, expected_y, ec.SECP521R1()
+ )
+
def test_load_ssh_public_key_ecdsa_nist_p256_trailing_data(self, backend):
ssh_key = (
b"ecdsa-sha2-nistp256 AAAAE2VjZHNhLXNoYTItbmlzdHAyNTYAAAAIbmlzdHAy"