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crypto: chacha20-methods: make associated_data param optional

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This commit is contained in:
SomberNight
2020-06-17 17:32:51 +02:00
parent b9db16327a
commit 725b6f1564
2 changed files with 42 additions and 8 deletions
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26
electrum/crypto.py
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@@ -268,14 +268,21 @@ def hmac_oneshot(key: bytes, msg: bytes, digest) -> bytes:
return hmac.new(key, msg, digest).digest()
def chacha20_poly1305_encrypt(*, key: bytes, nonce: bytes, associated_data: bytes, data: bytes) -> bytes:
def chacha20_poly1305_encrypt(
*,
key: bytes,
nonce: bytes,
associated_data: bytes = None,
data: bytes
) -> bytes:
assert isinstance(key, (bytes, bytearray))
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray, type(None)))
assert isinstance(data, (bytes, bytearray))
if HAS_CRYPTODOME:
cipher = CD_ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(associated_data)
if associated_data is not None:
cipher.update(associated_data)
ciphertext, mac = cipher.encrypt_and_digest(plaintext=data)
return ciphertext + mac
if HAS_CRYPTOGRAPHY:
@@ -284,14 +291,21 @@ def chacha20_poly1305_encrypt(*, key: bytes, nonce: bytes, associated_data: byte
raise Exception("no chacha20 backend found")
def chacha20_poly1305_decrypt(*, key: bytes, nonce: bytes, associated_data: bytes, data: bytes) -> bytes:
def chacha20_poly1305_decrypt(
*,
key: bytes,
nonce: bytes,
associated_data: bytes = None,
data: bytes
) -> bytes:
assert isinstance(key, (bytes, bytearray))
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray, type(None)))
assert isinstance(data, (bytes, bytearray))
if HAS_CRYPTODOME:
cipher = CD_ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(associated_data)
if associated_data is not None:
cipher.update(associated_data)
# raises ValueError if not valid (e.g. incorrect MAC)
return cipher.decrypt_and_verify(ciphertext=data[:-16], received_mac_tag=data[-16:])
if HAS_CRYPTOGRAPHY: