def testM2CryptoCompatibility(self):
message = b"HMAC by M2Crypto!"
signature = binascii.unhexlify("99cae3ec7b41ceb6e6619f2f85368cb3ae118b70")
key = rdf_crypto.EncryptionKey.FromHex("94bd4e0ecc8397a8b2cdbc4b127ee7b0")
h = rdf_crypto.HMAC(key)
self.assertEqual(h.HMAC(message), signature)
h.Verify(message, signature)
def testSHA256(self):
"""Tests that both types of signatures are ok."""
key = rdf_crypto.EncryptionKey.GenerateKey()
message = b"Hello World!"
h = rdf_crypto.HMAC(key)
signature_sha1 = h.HMAC(message)
signature_sha256 = h.HMAC(message, use_sha256=True)
self.assertNotEqual(signature_sha1, signature_sha256)
h.Verify(message, signature_sha1)
h.Verify(message, signature_sha256)
def testHMAC(self):
"""A basic test for the HMAC class."""
key = rdf_crypto.EncryptionKey.GenerateKey()
message = b"Hello World!"
h = rdf_crypto.HMAC(key)
signature = h.HMAC(message)
h.Verify(message, signature)
broken_message = message + b"!"
self.assertRaises(rdf_crypto.VerificationError, h.Verify,
broken_message, signature)
broken_signature = _Tamper(signature)
self.assertRaises(rdf_crypto.VerificationError, h.Verify,
b"Hello World!", broken_signature)
def _VerifyHMAC(self, comms=None):
"""Verifies the HMAC.
This method raises a DecryptionError if the received HMAC does not
verify. If the HMAC verifies correctly, True is returned.
Args:
comms: The comms RdfValue to verify.
Raises:
DecryptionError: The HMAC did not verify.
Returns:
True
"""
# Check the encrypted message integrity using HMAC.
if self.hmac_type == "SIMPLE_HMAC":
msg = comms.encrypted
digest = comms.hmac
elif self.hmac_type == "FULL_HMAC":
msg = b"".join([
comms.encrypted, comms.encrypted_cipher,
comms.encrypted_cipher_metadata,
comms.packet_iv.SerializeToString(),
struct.pack("<I", comms.api_version)
])
digest = comms.full_hmac
else:
raise DecryptionError("HMAC type no supported.")
try:
rdf_crypto.HMAC(self.cipher.hmac_key).Verify(msg, digest)
except rdf_crypto.VerificationError as e:
raise DecryptionError("HMAC verification failed: %s" % e)
return True
def GetHMAC(self): return rdf_crypto.HMAC(self.hmac_key.RawBytes())
def HMAC(self, *data):
return rdf_crypto.HMAC(self.cipher.hmac_key).HMAC(b"".join(data))
