def test_invalid_decrypt_or_update_after_verify(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
ct = cipher.encrypt(self.data_128)
mac = cipher.digest()
for method_name in "decrypt", "update":
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt_and_verify(ct, mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
def test_invalid_decrypt_or_update_after_verify(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
ct = cipher.encrypt(self.data_128)
mac = cipher.digest()
for method_name in "decrypt", "update":
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt_and_verify(ct, mac)
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
def test_valid_init_verify(self):
# Verify path INIT->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
mac = cipher.digest()
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.verify(mac)
def test_hex_mac(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
mac_hex = cipher.hexdigest()
self.assertEqual(cipher.digest(), unhexlify(mac_hex))
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.hexverify(mac_hex)
def test_loopback(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
pt = get_tag_random("plaintext", 16 * 100)
ct = cipher.encrypt(pt)
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
pt2 = cipher.decrypt(ct)
self.assertEqual(pt, pt2)
def test_either_encrypt_or_decrypt(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.encrypt(b"")
self.assertRaises(TypeError, cipher.decrypt, b"")
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.decrypt(b"")
self.assertRaises(TypeError, cipher.encrypt, b"")
def test_data_must_be_bytes(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.assertRaises(TypeError, cipher.encrypt, u'test1234567890-*')
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.assertRaises(TypeError, cipher.decrypt, u'test1234567890-*')
def test_nonce_attribute(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
self.assertEqual(cipher.nonce, self.nonce_96)
# By default, a 12 bytes long nonce is randomly generated
nonce1 = ChaCha20_Poly1305.new(key=self.key_256).nonce
nonce2 = ChaCha20_Poly1305.new(key=self.key_256).nonce
self.assertEqual(len(nonce1), 12)
self.assertNotEqual(nonce1, nonce2)
def test_hex_mac(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
mac_hex = cipher.hexdigest()
self.assertEqual(cipher.digest(), unhexlify(mac_hex))
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.hexverify(mac_hex)
def test_valid_init_verify(self):
# Verify path INIT->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
mac = cipher.digest()
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.verify(mac)
def test_invalid_mac(self):
from Cryptodome.Util.strxor import strxor_c
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
ct, mac = cipher.encrypt_and_digest(self.data_128)
invalid_mac = strxor_c(mac, 0x01)
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
self.assertRaises(ValueError, cipher.decrypt_and_verify, ct,
invalid_mac)
def test_loopback(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
pt = get_tag_random("plaintext", 16 * 100)
ct = cipher.encrypt(pt)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
pt2 = cipher.decrypt(ct)
self.assertEqual(pt, pt2)
def test_either_encrypt_or_decrypt(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.encrypt(b"")
self.assertRaises(TypeError, cipher.decrypt, b"")
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(b"")
self.assertRaises(TypeError, cipher.encrypt, b"")
def test_nonce_attribute(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.assertEqual(cipher.nonce, self.nonce_96)
# By default, a 12 bytes long nonce is randomly generated
nonce1 = ChaCha20_Poly1305.new(key=self.key_256).nonce
nonce2 = ChaCha20_Poly1305.new(key=self.key_256).nonce
self.assertEqual(len(nonce1), 12)
self.assertNotEqual(nonce1, nonce2)
def test_valid_init_encrypt_decrypt_digest_verify(self):
# No authenticated data, fixed plaintext
# Verify path INIT->ENCRYPT->DIGEST
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
ct = cipher.encrypt(self.data_128)
mac = cipher.digest()
# Verify path INIT->DECRYPT->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
def test_valid_encrypt_and_digest_decrypt_and_verify(self):
# encrypt_and_digest
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
ct, mac = cipher.encrypt_and_digest(self.data_128)
# decrypt_and_verify
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
pt = cipher.decrypt_and_verify(ct, mac)
self.assertEqual(self.data_128, pt)
def test_valid_init_update_digest_verify(self):
# No plaintext, fixed authenticated data
# Verify path INIT->UPDATE->DIGEST
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
mac = cipher.digest()
# Verify path INIT->UPDATE->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
cipher.verify(mac)
def test_invalid_mac(self):
from Cryptodome.Util.strxor import strxor_c
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
ct, mac = cipher.encrypt_and_digest(self.data_128)
invalid_mac = strxor_c(mac, 0x01)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.assertRaises(ValueError, cipher.decrypt_and_verify, ct,
invalid_mac)
def test_invalid_encrypt_or_update_after_digest(self):
for method_name in "encrypt", "update":
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.encrypt(self.data_128)
cipher.digest()
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.encrypt_and_digest(self.data_128)
def test_invalid_encrypt_or_update_after_digest(self):
for method_name in "encrypt", "update":
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.encrypt(self.data_128)
cipher.digest()
self.assertRaises(TypeError, getattr(cipher, method_name),
self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.encrypt_and_digest(self.data_128)
def test_valid_multiple_digest_or_verify(self):
# Multiple calls to digest
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
first_mac = cipher.digest()
for x in range(4):
self.assertEqual(first_mac, cipher.digest())
# Multiple calls to verify
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(self.data_128)
for x in range(5):
cipher.verify(first_mac)
def test_valid_init_encrypt_decrypt_digest_verify(self):
# No authenticated data, fixed plaintext
# Verify path INIT->ENCRYPT->DIGEST
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
ct = cipher.encrypt(self.data_128)
mac = cipher.digest()
# Verify path INIT->DECRYPT->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.decrypt(ct)
cipher.verify(mac)
def test_valid_encrypt_and_digest_decrypt_and_verify(self):
# encrypt_and_digest
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
ct, mac = cipher.encrypt_and_digest(self.data_128)
# decrypt_and_verify
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
pt = cipher.decrypt_and_verify(ct, mac)
self.assertEqual(self.data_128, pt)
def test_valid_init_update_digest_verify(self):
# No plaintext, fixed authenticated data
# Verify path INIT->UPDATE->DIGEST
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
mac = cipher.digest()
# Verify path INIT->UPDATE->VERIFY
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
cipher.verify(mac)
def runTest(self):
for assoc_data, pt, ct, mac, key, nonce in self.test_vectors:
# Encrypt
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(assoc_data)
ct2, mac2 = cipher.encrypt_and_digest(pt)
self.assertEqual(ct, ct2)
self.assertEqual(mac, mac2)
# Decrypt
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(assoc_data)
pt2 = cipher.decrypt_and_verify(ct, mac)
self.assertEqual(pt, pt2)
def runTest(self):
for assoc_data, pt, ct, mac, key, nonce in self.test_vectors:
# Encrypt
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(assoc_data)
ct2, mac2 = cipher.encrypt_and_digest(pt)
self.assertEqual(ct, ct2)
self.assertEqual(mac, mac2)
# Decrypt
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(assoc_data)
pt2 = cipher.decrypt_and_verify(ct, mac)
self.assertEqual(pt, pt2)
def test_valid_multiple_digest_or_verify(self):
# Multiple calls to digest
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
first_mac = cipher.digest()
for x in range(4):
self.assertEqual(first_mac, cipher.digest())
# Multiple calls to verify
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(self.data_128)
for x in range(5):
cipher.verify(first_mac)
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, type(None)))
assert isinstance(data, (bytes, bytearray))
assert len(key) == 32, f"unexpected key size: {len(key)} (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:
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:
a = CG_aead.ChaCha20Poly1305(key)
try:
return a.decrypt(nonce, data, associated_data)
except cryptography.exceptions.InvalidTag as e:
raise ValueError("invalid tag") from e
raise Exception("no chacha20 backend found")
def aead_encrypt(key: bytes, nonce: int, associated_data: bytes,
data: bytes) -> bytes:
nonce_bytes = get_nonce_bytes(nonce)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce_bytes)
cipher.update(associated_data)
ciphertext, mac = cipher.encrypt_and_digest(plaintext=data)
return ciphertext + mac
def receiveM2(self, data):
logger.info("Receive M2")
pvDict = OPACK.decode(data)
tlv = TLV8Box.decodeFromData(pvDict["pd"]).toDict()
searching_device_pub_key = x25519.X25519PublicKey.from_public_bytes(
bytes(tlv[0x03]))
self.shared_secret = self.session_keys.private.exchange(
searching_device_pub_key)
hkdf_inst = hkdf.Hkdf("Pair-Verify-Encrypt-Salt".encode(),
self.shared_secret,
hash=hashlib.sha512)
key = hkdf_inst.expand("Pair-Verify-Encrypt-Info".encode(), 32)
encryptedData = bytes(tlv[0x05])[:-16]
authKey = bytes(tlv[0x05])[-16:]
nonce = "PV-Msg02".encode()
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
plainData = cipher.decrypt_and_verify(encryptedData, authKey)
plainTLV = TLV8Box.decodeFromData(plainData).toDict()
# plainTLV contains authentication data:
# {
# 9: Signature over public keys of grantor and requestor
# 10: Apple ID certificate (NSDataCompressed)
# 20: Apple ID validation record (NSDataCompressed)
# }
logger.debug(f"Identity TLV: {plainTLV}")
self.sendM3()
def test_bytearray(self):
# Encrypt
key_ba = bytearray(self.key_256)
nonce_ba = bytearray(self.nonce_96)
header_ba = bytearray(self.data_128)
data_ba = bytearray(self.data_128)
cipher1 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher1.update(self.data_128)
ct = cipher1.encrypt(self.data_128)
tag = cipher1.digest()
cipher2 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
key_ba[:3] = b'\xFF\xFF\xFF'
nonce_ba[:3] = b'\xFF\xFF\xFF'
cipher2.update(header_ba)
header_ba[:3] = b'\xFF\xFF\xFF'
ct_test = cipher2.encrypt(data_ba)
data_ba[:3] = b'\x99\x99\x99'
tag_test = cipher2.digest()
self.assertEqual(ct, ct_test)
self.assertEqual(tag, tag_test)
self.assertEqual(cipher1.nonce, cipher2.nonce)
# Decrypt
key_ba = bytearray(self.key_256)
nonce_ba = bytearray(self.nonce_96)
header_ba = bytearray(self.data_128)
ct_ba = bytearray(ct)
tag_ba = bytearray(tag)
del data_ba
cipher3 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
key_ba[:3] = b'\xFF\xFF\xFF'
nonce_ba[:3] = b'\xFF\xFF\xFF'
cipher3.update(header_ba)
header_ba[:3] = b'\xFF\xFF\xFF'
pt_test = cipher3.decrypt(ct_ba)
ct_ba[:3] = b'\xFF\xFF\xFF'
cipher3.verify(tag_ba)
self.assertEqual(pt_test, self.data_128)
def test_memoryview(self):
# Encrypt
key_mv = memoryview(bytearray(self.key_256))
nonce_mv = memoryview(bytearray(self.nonce_96))
header_mv = memoryview(bytearray(self.data_128))
data_mv = memoryview(bytearray(self.data_128))
cipher1 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher1.update(self.data_128)
ct = cipher1.encrypt(self.data_128)
tag = cipher1.digest()
cipher2 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
key_mv[:3] = b'\xFF\xFF\xFF'
nonce_mv[:3] = b'\xFF\xFF\xFF'
cipher2.update(header_mv)
header_mv[:3] = b'\xFF\xFF\xFF'
ct_test = cipher2.encrypt(data_mv)
data_mv[:3] = b'\x99\x99\x99'
tag_test = cipher2.digest()
self.assertEqual(ct, ct_test)
self.assertEqual(tag, tag_test)
self.assertEqual(cipher1.nonce, cipher2.nonce)
# Decrypt
key_mv = memoryview(bytearray(self.key_256))
nonce_mv = memoryview(bytearray(self.nonce_96))
header_mv = memoryview(bytearray(self.data_128))
ct_mv = memoryview(bytearray(ct))
tag_mv = memoryview(bytearray(tag))
del data_mv
cipher3 = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
key_mv[:3] = b'\xFF\xFF\xFF'
nonce_mv[:3] = b'\xFF\xFF\xFF'
cipher3.update(header_mv)
header_mv[:3] = b'\xFF\xFF\xFF'
pt_test = cipher3.decrypt(ct_mv)
ct_mv[:3] = b'\x99\x99\x99'
cipher3.verify(tag_mv)
self.assertEqual(pt_test, self.data_128)
def test_corrupt_decrypt(self, tv):
self._id = "Wycheproof Corrupt Decrypt ChaCha20-Poly1305 Test #" + str(tv.id)
if len(tv.iv) == 0 or len(tv.ct) < 1:
return
cipher = ChaCha20_Poly1305.new(key=tv.key, nonce=tv.iv)
cipher.update(tv.aad)
ct_corrupt = strxor(tv.ct, b"\x00" * (len(tv.ct) - 1) + b"\x01")
self.assertRaises(ValueError, cipher.decrypt_and_verify, ct_corrupt, tv.tag)
def runTest(self):
# Encrypt/Decrypt data and test output parameter
key = b'4' * 32
nonce = b'5' * 12
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
pt = b'5' * 16
ct = cipher.encrypt(pt)
output = bytearray(16)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
res = cipher.encrypt(pt, output=output)
self.assertEqual(ct, output)
self.assertEqual(res, None)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
res = cipher.decrypt(ct, output=output)
self.assertEqual(pt, output)
self.assertEqual(res, None)
import sys
if sys.version[:3] != '2.6':
output = memoryview(bytearray(16))
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.encrypt(pt, output=output)
self.assertEqual(ct, output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.decrypt(ct, output=output)
self.assertEqual(pt, output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(TypeError, cipher.encrypt, pt, output=b'0' * 16)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(TypeError, cipher.decrypt, ct, output=b'0' * 16)
shorter_output = bytearray(7)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(ValueError,
cipher.encrypt,
pt,
output=shorter_output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(ValueError,
cipher.decrypt,
ct,
output=shorter_output)
def aead_decrypt(key: bytes, nonce: int, associated_data: bytes,
data: bytes) -> bytes:
nonce_bytes = get_nonce_bytes(nonce)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce_bytes)
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:])
def test_message_chunks(self):
# Validate that both associated data and plaintext/ciphertext
# can be broken up in chunks of arbitrary length
auth_data = get_tag_random("authenticated data", 127)
plaintext = get_tag_random("plaintext", 127)
cipher = ChaCha20_Poly1305.new(key=self.key_256, nonce=self.nonce_96)
cipher.update(auth_data)
ciphertext, ref_mac = cipher.encrypt_and_digest(plaintext)
def break_up(data, chunk_length):
return [
data[i:i + chunk_length]
for i in range(0, len(data), chunk_length)
]
# Encryption
for chunk_length in 1, 2, 3, 7, 10, 13, 16, 40, 80, 128:
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
for chunk in break_up(auth_data, chunk_length):
cipher.update(chunk)
pt2 = b""
for chunk in break_up(ciphertext, chunk_length):
pt2 += cipher.decrypt(chunk)
self.assertEqual(plaintext, pt2)
cipher.verify(ref_mac)
# Decryption
for chunk_length in 1, 2, 3, 7, 10, 13, 16, 40, 80, 128:
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
for chunk in break_up(auth_data, chunk_length):
cipher.update(chunk)
ct2 = b""
for chunk in break_up(plaintext, chunk_length):
ct2 += cipher.encrypt(chunk)
self.assertEqual(ciphertext, ct2)
self.assertEquals(cipher.digest(), ref_mac)
def test_message_chunks(self):
# Validate that both associated data and plaintext/ciphertext
# can be broken up in chunks of arbitrary length
auth_data = get_tag_random("authenticated data", 127)
plaintext = get_tag_random("plaintext", 127)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.update(auth_data)
ciphertext, ref_mac = cipher.encrypt_and_digest(plaintext)
def break_up(data, chunk_length):
return [data[i:i+chunk_length] for i in range(0, len(data),
chunk_length)]
# Encryption
for chunk_length in 1, 2, 3, 7, 10, 13, 16, 40, 80, 128:
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
for chunk in break_up(auth_data, chunk_length):
cipher.update(chunk)
pt2 = b""
for chunk in break_up(ciphertext, chunk_length):
pt2 += cipher.decrypt(chunk)
self.assertEqual(plaintext, pt2)
cipher.verify(ref_mac)
# Decryption
for chunk_length in 1, 2, 3, 7, 10, 13, 16, 40, 80, 128:
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
for chunk in break_up(auth_data, chunk_length):
cipher.update(chunk)
ct2 = b""
for chunk in break_up(plaintext, chunk_length):
ct2 += cipher.encrypt(chunk)
self.assertEqual(ciphertext, ct2)
self.assertEquals(cipher.digest(), ref_mac)
def test_invalid_mixing_encrypt_decrypt(self):
# Once per method, with or without assoc. data
for method1_name, method2_name in (("encrypt", "decrypt"),
("decrypt", "encrypt")):
for assoc_data_present in (True, False):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
if assoc_data_present:
cipher.update(self.data_128)
getattr(cipher, method1_name)(self.data_128)
self.assertRaises(TypeError, getattr(cipher, method2_name),
self.data_128)
def can_decrypt(key, package):
try:
jv = decode_package(package)
cipher = ChaCha20_Poly1305.new(key=key, nonce=jv['nonce'])
cipher.update(jv['header'])
plaintext = cipher.decrypt_and_verify(jv['ciphertext'], jv['tag'])
#print("The message was: " + str(plaintext))
return True, plaintext
except ValueError:
#print("Incorrect decryption")
return False, None
def test_invalid_mixing_encrypt_decrypt(self):
# Once per method, with or without assoc. data
for method1_name, method2_name in (("encrypt", "decrypt"),
("decrypt", "encrypt")):
for assoc_data_present in (True, False):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
if assoc_data_present:
cipher.update(self.data_128)
getattr(cipher, method1_name)(self.data_128)
self.assertRaises(TypeError, getattr(cipher, method2_name),
self.data_128)
def pyCrypto():
import Cryptodome
from Cryptodome.Cipher import AES, ChaCha20, DES, DES3, ARC2, ARC4, Blowfish, CAST, PKCS1_v1_5, PKCS1_OAEP, ChaCha20_Poly1305, Salsa20
from Cryptodome.PublicKey import ElGamal
Cryptodome.Cipher.AES.new() # Noncompliant
Cryptodome.Other.AES.new() # OK
AES.new(key=key) # Noncompliant
ChaCha20.new(key=key) # Noncompliant
DES.new(key=key) # Noncompliant
DES3.new(key=key) # Noncompliant
ARC2.new(key=key) # Noncompliant
ARC4.new(key=key) # Noncompliant
Blowfish.new(key=key) # Noncompliant
CAST.new(key=key) # Noncompliant
PKCS1_v1_5.new(key=key) # Noncompliant
PKCS1_OAEP.new(key=key) # Noncompliant
ChaCha20_Poly1305.new(key=key) # Noncompliant
Salsa20.new(key=key) # Noncompliant
ElGamal.generate(key_size) # Noncompliant
def runTest(self):
# Encrypt/Decrypt data and test output parameter
key = b'4' * 32
nonce = b'5' * 12
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
pt = b'5' * 16
ct = cipher.encrypt(pt)
output = bytearray(16)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
res = cipher.encrypt(pt, output=output)
self.assertEqual(ct, output)
self.assertEqual(res, None)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
res = cipher.decrypt(ct, output=output)
self.assertEqual(pt, output)
self.assertEqual(res, None)
import sys
if sys.version[:3] != '2.6':
output = memoryview(bytearray(16))
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.encrypt(pt, output=output)
self.assertEqual(ct, output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.decrypt(ct, output=output)
self.assertEqual(pt, output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(TypeError, cipher.encrypt, pt, output=b'0'*16)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(TypeError, cipher.decrypt, ct, output=b'0'*16)
shorter_output = bytearray(7)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(ValueError, cipher.encrypt, pt, output=shorter_output)
cipher = ChaCha20_Poly1305.new(key=key, nonce=nonce)
self.assertRaises(ValueError, cipher.decrypt, ct, output=shorter_output)
def test_valid_multiple_encrypt_or_decrypt(self):
for method_name in "encrypt", "decrypt":
for auth_data in (None, b"333", self.data_128,
self.data_128 + b"3"):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
if auth_data is not None:
cipher.update(auth_data)
method = getattr(cipher, method_name)
method(self.data_128)
method(self.data_128)
method(self.data_128)
method(self.data_128)
def test_valid_multiple_encrypt_or_decrypt(self):
for method_name in "encrypt", "decrypt":
for auth_data in (None, b"333", self.data_128,
self.data_128 + b"3"):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
if auth_data is not None:
cipher.update(auth_data)
method = getattr(cipher, method_name)
method(self.data_128)
method(self.data_128)
method(self.data_128)
method(self.data_128)
def encrypt(self, msg, aad, iv, key):
"""Content Encryption with AEAD_XCHACHA20_POLY1305
:param msg: text to be encrypt in bytes
:param aad: additional authenticated data in bytes
:param iv: initialization vector in bytes
:param key: encrypted key in bytes
:return: (ciphertext, tag)
"""
self.check_iv(iv)
chacha = Cryptodome_ChaCha20_Poly1305.new(key=key, nonce=iv)
chacha.update(aad)
ciphertext, tag = chacha.encrypt_and_digest(msg)
return ciphertext, tag
def decrypt(self, ciphertext, aad, iv, tag, key):
"""Content Decryption with AEAD_XCHACHA20_POLY1305
:param ciphertext: ciphertext in bytes
:param aad: additional authenticated data in bytes
:param iv: initialization vector in bytes
:param tag: authentication tag in bytes
:param key: encrypted key in bytes
:return: message
"""
self.check_iv(iv)
chacha = Cryptodome_ChaCha20_Poly1305.new(key=key, nonce=iv)
chacha.update(aad)
return chacha.decrypt_and_verify(ciphertext, tag)
def chacha20_poly1305_encrypt(*, key: bytes, nonce: bytes, associated_data: bytes, data: bytes) -> bytes:
assert isinstance(key, (bytes, bytearray))
assert isinstance(nonce, (bytes, bytearray))
assert isinstance(associated_data, (bytes, bytearray))
assert isinstance(data, (bytes, bytearray))
if HAS_CRYPTODOME:
cipher = CD_ChaCha20_Poly1305.new(key=key, nonce=nonce)
cipher.update(associated_data)
ciphertext, mac = cipher.encrypt_and_digest(plaintext=data)
return ciphertext + mac
if HAS_CRYPTOGRAPHY:
a = CG_aead.ChaCha20Poly1305(key)
return a.encrypt(nonce, data, associated_data)
raise Exception("no chacha20 backend found")
def test_encrypt(self, tv):
self._id = "Wycheproof Encrypt ChaCha20-Poly1305 Test #" + str(tv.id)
try:
cipher = ChaCha20_Poly1305.new(key=tv.key, nonce=tv.iv)
except ValueError as e:
assert len(tv.iv) not in (8, 12) and "Nonce must be" in str(e)
return
cipher.update(tv.aad)
ct, tag = cipher.encrypt_and_digest(tv.msg)
if tv.valid:
self.assertEqual(ct, tv.ct)
self.assertEqual(tag, tv.tag)
self.warn(tv)
def test_decrypt(self, tv):
self._id = "Wycheproof Decrypt ChaCha20-Poly1305 Test #" + str(tv.id)
try:
cipher = ChaCha20_Poly1305.new(key=tv.key, nonce=tv.iv)
except ValueError as e:
assert len(tv.iv) not in (8, 12) and "Nonce must be" in str(e)
return
cipher.update(tv.aad)
try:
pt = cipher.decrypt_and_verify(tv.ct, tv.tag)
except ValueError:
assert not tv.valid
else:
assert tv.valid
self.assertEqual(pt, tv.msg)
self.warn(tv)
def test_nonce(self):
# Nonce can only be 8 or 12 bytes
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=b'H' * 8)
self.assertEqual(len(cipher.nonce), 8)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=b'H' * 12)
self.assertEqual(len(cipher.nonce), 12)
# If not passed, the nonce is created randomly
cipher = ChaCha20_Poly1305.new(key=self.key_256)
nonce1 = cipher.nonce
cipher = ChaCha20_Poly1305.new(key=self.key_256)
nonce2 = cipher.nonce
self.assertEqual(len(nonce1), 12)
self.assertNotEqual(nonce1, nonce2)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
ct = cipher.encrypt(self.data_128)
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.assertEquals(ct, cipher.encrypt(self.data_128))
def test_block_size(self):
# Not based on block ciphers
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
self.failIf(hasattr(cipher, 'block_size'))
def test_null_encryption_decryption(self):
for func in "encrypt", "decrypt":
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
result = getattr(cipher, func)(b"")
self.assertEqual(result, b"")
def test_mac_len(self):
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
_, mac = cipher.encrypt_and_digest(self.data_128)
self.assertEqual(len(mac), 16)
def test_valid_init_digest(self):
# Verify path INIT->DIGEST
cipher = ChaCha20_Poly1305.new(key=self.key_256,
nonce=self.nonce_96)
cipher.digest()
