tcrypto: add chacha20_decrypt; unused for now - electrum - Electrum Bitcoin wallet
HTML git clone https://git.parazyd.org/electrum
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---
DIR commit 9740744d70461d9b0f02a78f836784bc91ff2d1a
DIR parent 549b9a95df6fedbf0880df139a99f419931150e1
HTML Author: SomberNight <somber.night@protonmail.com>
Date: Wed, 10 Mar 2021 17:13:42 +0100
crypto: add chacha20_decrypt; unused for now
Diffstat:
M electrum/crypto.py | 27 +++++++++++++++++++++++++--
M electrum/tests/test_bitcoin.py | 16 +++++++++++++---
2 files changed, 38 insertions(+), 5 deletions(-)
---
DIR diff --git a/electrum/crypto.py b/electrum/crypto.py
t@@ -338,6 +338,8 @@ def chacha20_poly1305_encrypt(
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray, type(None)))
assert isinstance(data, (bytes, bytearray))
+ assert len(key) == 32, f"unexpected key size: {len(nonce)} (expected: 32)"
+ assert len(nonce) == 12, f"unexpected nonce size: {len(nonce)} (expected: 12)"
if HAS_CRYPTODOME:
cipher = CD_ChaCha20_Poly1305.new(key=key, nonce=nonce)
if associated_data is not None:
t@@ -361,6 +363,8 @@ def chacha20_poly1305_decrypt(
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray, type(None)))
assert isinstance(data, (bytes, bytearray))
+ assert len(key) == 32, f"unexpected key size: {len(nonce)} (expected: 32)"
+ assert len(nonce) == 12, f"unexpected nonce size: {len(nonce)} (expected: 12)"
if HAS_CRYPTODOME:
cipher = CD_ChaCha20_Poly1305.new(key=key, nonce=nonce)
if associated_data is not None:
t@@ -380,14 +384,33 @@ def chacha20_encrypt(*, key: bytes, nonce: bytes, data: bytes) -> bytes:
assert isinstance(key, (bytes, bytearray))
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(data, (bytes, bytearray))
- assert len(nonce) == 8, f"unexpected nonce size: {len(nonce)} (expected: 8)"
+ assert len(key) == 32, f"unexpected key size: {len(nonce)} (expected: 32)"
+ assert len(nonce) in (8, 12), f"unexpected nonce size: {len(nonce)} (expected: 8 or 12)"
if HAS_CRYPTODOME:
cipher = CD_ChaCha20.new(key=key, nonce=nonce)
return cipher.encrypt(data)
if HAS_CRYPTOGRAPHY:
- nonce = bytes(8) + nonce # cryptography wants 16 byte nonces
+ nonce = bytes(16 - len(nonce)) + nonce # cryptography wants 16 byte nonces
algo = CG_algorithms.ChaCha20(key=key, nonce=nonce)
cipher = CG_Cipher(algo, mode=None, backend=CG_default_backend())
encryptor = cipher.encryptor()
return encryptor.update(data)
raise Exception("no chacha20 backend found")
+
+
+def chacha20_decrypt(*, key: bytes, nonce: bytes, data: bytes) -> bytes:
+ assert isinstance(key, (bytes, bytearray))
+ assert isinstance(nonce, (bytes, bytearray))
+ assert isinstance(data, (bytes, bytearray))
+ assert len(key) == 32, f"unexpected key size: {len(nonce)} (expected: 32)"
+ assert len(nonce) in (8, 12), f"unexpected nonce size: {len(nonce)} (expected: 8 or 12)"
+ if HAS_CRYPTODOME:
+ cipher = CD_ChaCha20.new(key=key, nonce=nonce)
+ return cipher.decrypt(data)
+ if HAS_CRYPTOGRAPHY:
+ nonce = bytes(16 - len(nonce)) + nonce # cryptography wants 16 byte nonces
+ algo = CG_algorithms.ChaCha20(key=key, nonce=nonce)
+ cipher = CG_Cipher(algo, mode=None, backend=CG_default_backend())
+ decryptor = cipher.decryptor()
+ return decryptor.update(data)
+ raise Exception("no chacha20 backend found")
DIR diff --git a/electrum/tests/test_bitcoin.py b/electrum/tests/test_bitcoin.py
t@@ -302,12 +302,22 @@ class Test_bitcoin(ElectrumTestCase):
crypto.chacha20_poly1305_decrypt(key=key, nonce=nonce, data=data, associated_data=b''))
@needs_test_with_all_chacha20_implementations
- def test_chacha20_encrypt(self):
+ def test_chacha20_encrypt__8_byte_nonce(self):
key = bytes.fromhex('37326d9d69a83b815ddfd947d21b0dd39111e5b6a5a44042c44d570ea03e3179')
nonce = bytes.fromhex('0102030405060708')
data = bytes.fromhex('38a0e0a7c865fe9ca31f0730cfcab610f18e6da88dc3790f1d243f711a257c78')
- self.assertEqual(bytes.fromhex('f62fbd74d197323c7c3d5658476a884d38ee6f4b5500add1e8dc80dcd9c15dff'),
- crypto.chacha20_encrypt(key=key, nonce=nonce, data=data))
+ ciphertext = crypto.chacha20_encrypt(key=key, nonce=nonce, data=data)
+ self.assertEqual(bytes.fromhex('f62fbd74d197323c7c3d5658476a884d38ee6f4b5500add1e8dc80dcd9c15dff'), ciphertext)
+ self.assertEqual(data, crypto.chacha20_decrypt(key=key, nonce=nonce, data=ciphertext))
+
+ @needs_test_with_all_chacha20_implementations
+ def test_chacha20_encrypt__12_byte_nonce(self):
+ key = bytes.fromhex('37326d9d69a83b815ddfd947d21b0dd39111e5b6a5a44042c44d570ea03e3179')
+ nonce = bytes.fromhex('010203040506070809101112')
+ data = bytes.fromhex('38a0e0a7c865fe9ca31f0730cfcab610f18e6da88dc3790f1d243f711a257c78')
+ ciphertext = crypto.chacha20_encrypt(key=key, nonce=nonce, data=data)
+ self.assertEqual(bytes.fromhex('c0b1cb75c3c23c13f47dab393add738c92c62c4e2546cb3bf2b48269a4184028'), ciphertext)
+ self.assertEqual(data, crypto.chacha20_decrypt(key=key, nonce=nonce, data=ciphertext))
def test_sha256d(self):
self.assertEqual(b'\x95MZI\xfdp\xd9\xb8\xbc\xdb5\xd2R&x)\x95\x7f~\xf7\xfalt\xf8\x84\x19\xbd\xc5\xe8"\t\xf4',