def test_CMAC_test_vectors(self):
# test using official RFC AES_CMAC test vectors
key = Fernet.generate_key()
fernet = Fernet(key)
K = '2b7e151628aed2a6abf7158809cf4f3c'.decode('hex')
LENGTH = 0
M = ''
CMAC = 'bb1d6929e95937287fa37d129b756746'.decode('hex')
assert fernet._AES_CMAC_generate(K, M, LENGTH) == CMAC
LENGTH = 16
M = '6bc1bee22e409f96e93d7e117393172a'.decode('hex')
CMAC = '070a16b46b4d4144f79bdd9dd04a287c'.decode('hex')
assert fernet._AES_CMAC_generate(K, M, LENGTH) == CMAC
LENGTH = 40
M = '6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411'.decode('hex')
CMAC = 'dfa66747de9ae63030ca32611497c827'.decode('hex')
assert fernet._AES_CMAC_generate(K, M, LENGTH) == CMAC
LENGTH = 64
M = '6bc1bee22e409f96e93d7e117393172aae2d8a571e03ac9c9eb76fac45af8e5130c81c46a35ce411e5fbc1191a0a52eff69f2445df4f9b17ad2b417be66c3710'.decode('hex')
CMAC = '51f0bebf7e3b9d92fc49741779363cfe'.decode('hex')
assert fernet._AES_CMAC_generate(K, M, LENGTH) == CMAC
def test_CMAC_verify(self):
# test CMAC verification function
key = Fernet.generate_key()
fernet = Fernet(key)
# test against the cryptography.io library APIs
for i in range(20):
M = os.urandom(i)
K = os.urandom(16)
# use library API generation
c = cmac.CMAC(algorithms.AES(K), backend=default_backend())
c.update(M)
lib_cmac = c.finalize()
# verify a library generated cmac
assert fernet._AES_CMAC_verify(K, M, len(M), lib_cmac)
# verify against our own API
cmac_ = fernet._AES_CMAC_generate(K, M, len(M))
assert fernet._AES_CMAC_verify(K, M, len(M), cmac_)
# # library verify our generated cmac
c = cmac.CMAC(algorithms.AES(K), backend=default_backend())
c.update(M)
try:
c.verify(cmac_)
except Exception:
raise Exception
def test_CMAC_generate(self):
# test AES_CMAC generation
key = Fernet.generate_key()
fernet = Fernet(key)
# test against the cryptographi.io library APIs
for i in range(20):
M = os.urandom(i)
K = os.urandom(16)
# use library's API to generate CMAC
c = cmac.CMAC(algorithms.AES(K), backend=default_backend())
c.update(M)
lib_cmac = c.finalize()
# use our function to generate CMAC
cmac_ = fernet._AES_CMAC_generate(K, M, len(M))
# verify library CMAC vs our CMAC
assert cmac_ == lib_cmac