def decrypt(cls, ciphertext_and_tag, aad, key, iv):
try:
return aead.AESCCM(key,
cls.tag_bytes).decrypt(iv, ciphertext_and_tag,
aad)
except cryptography.exceptions.InvalidTag:
raise ProtectionInvalid("Tag invalid")
def TestInput(input_bytes):
if len(input_bytes) < 12:
return
fdp = atheris.FuzzedDataProvider(input_bytes)
choice = fdp.ConsumeIntInRange(1, 4)
if choice == 1:
cipher = aead.ChaCha20Poly1305(aead.ChaCha20Poly1305.generate_key())
if choice == 2:
cipher = aead.AESGCM(aead.AESGCM.generate_key(bit_length=128))
if choice == 3:
cipher = aead.AESOCB3(aead.AESOCB3.generate_key(bit_length=128))
if choice == 4:
cipher = aead.AESCCM(aead.AESCCM.generate_key(bit_length=128))
msg = fdp.ConsumeBytes(32)
authentext = fdp.ConsumeBytes(32)
nonce = fdp.ConsumeBytes(12)
if len(nonce) < 12:
return
ciphertext = cipher.encrypt(nonce, msg, authentext)
plaintext = cipher.decrypt(nonce, ciphertext, authentext)
assert (plaintext == msg), "Encryption/Decrption error!"
def encrypt(cls, plaintext, aad, key, iv):
return aead.AESCCM(key, cls.tag_bytes).encrypt(iv, plaintext, aad)
def aes_ccm_decrypt(k, n, m, a=b"", tag_length=4):
c = aead.AESCCM(k, tag_length)
return c.decrypt(n, m, a)
def aes_ccm(k, n, m, a=b'', tag_length=4):
c = aead.AESCCM(k, tag_length)
return c.encrypt(n, m, a)