def verify(self, received_mac_tag):
"""Validate the *binary* MAC tag.
The caller invokes this function at the very end.
This method checks if the decrypted message is indeed valid
(that is, if the key is correct) and it has not been
tampered with while in transit.
:Parameters:
received_mac_tag : bytes/bytearray/memoryview
This is the *binary* MAC, as received from the sender.
:Raises ValueError:
if the MAC does not match. The message has been tampered with
or the key is incorrect.
"""
if self.verify not in self._next:
raise TypeError("verify() cannot be called"
" when encrypting a message")
self._next = [self.verify]
self._digest()
secret = get_random_bytes(16)
mac1 = BLAKE2s.new(digest_bits=160, key=secret, data=self._mac_tag)
mac2 = BLAKE2s.new(digest_bits=160, key=secret, data=received_mac_tag)
if mac1.digest() != mac2.digest():
raise ValueError("MAC check failed")
def verify(self, received_mac_tag):
"""Validate the *binary* MAC tag.
Call this method after the final `decrypt` (the one with no arguments)
to check if the message is authentic and valid.
:Parameters:
received_mac_tag : bytes/bytearray/memoryview
This is the *binary* MAC, as received from the sender.
:Raises ValueError:
if the MAC does not match. The message has been tampered with
or the key is incorrect.
"""
if self.verify not in self._next:
raise TypeError("verify() cannot be called now for this cipher")
assert (len(self._cache_P) == 0)
self._next = [self.verify]
if self._mac_tag is None:
self._compute_mac_tag()
secret = get_random_bytes(16)
mac1 = BLAKE2s.new(digest_bits=160, key=secret, data=self._mac_tag)
mac2 = BLAKE2s.new(digest_bits=160, key=secret, data=received_mac_tag)
if mac1.digest() != mac2.digest():
raise ValueError("MAC check failed")
def verify(self, mac_tag):
"""Verify that a given **binary** MAC (computed by another party)
is valid.
Args:
mac_tag (byte string/byte array/memoryview): the expected MAC of the message.
Raises:
ValueError: if the MAC does not match. It means that the message
has been tampered with or that the MAC key is incorrect.
"""
secret = get_random_bytes(16)
mac1 = BLAKE2s.new(digest_bits=160, key=secret, data=mac_tag)
mac2 = BLAKE2s.new(digest_bits=160, key=secret, data=self.digest())
if mac1.digest() != mac2.digest():
raise ValueError("MAC check failed")
def runTest(self):
key = RSA.generate(1024)
signer = pkcs1_15.new(key)
hash_names = ("MD2", "MD4", "MD5", "RIPEMD160", "SHA1",
"SHA224", "SHA256", "SHA384", "SHA512",
"SHA3_224", "SHA3_256", "SHA3_384", "SHA3_512")
for name in hash_names:
hashed = load_hash_by_name(name).new(b("Test"))
signer.sign(hashed)
from crypto.Hash import BLAKE2b, BLAKE2s
for hash_size in (20, 32, 48, 64):
hashed_b = BLAKE2b.new(digest_bytes=hash_size, data=b("Test"))
signer.sign(hashed_b)
for hash_size in (16, 20, 28, 32):
hashed_s = BLAKE2s.new(digest_bytes=hash_size, data=b("Test"))
signer.sign(hashed_s)