def test_encryption_cycle_with_caching():
algorithm = Algorithm.AES_256_GCM_IV12_TAG16_HKDF_SHA384_ECDSA_P384
frame_length = 1024
key_provider = fake_kms_key_provider(algorithm.kdf_input_len)
cache = aws_encryption_sdk.LocalCryptoMaterialsCache(capacity=10)
ccmm = aws_encryption_sdk.CachingCryptoMaterialsManager(
master_key_provider=key_provider, cache=cache, max_age=3600.0, max_messages_encrypted=5
)
encrypt_kwargs = dict(
source=VALUES["plaintext_128"],
materials_manager=ccmm,
encryption_context=VALUES["encryption_context"],
frame_length=frame_length,
algorithm=algorithm,
)
encrypt_cache_key = build_encryption_materials_cache_key(
partition=ccmm.partition_name,
request=EncryptionMaterialsRequest(
encryption_context=VALUES["encryption_context"],
frame_length=frame_length,
algorithm=algorithm,
plaintext_length=len(VALUES["plaintext_128"]),
),
)
ciphertext, header = aws_encryption_sdk.encrypt(**encrypt_kwargs)
decrypt_cache_key = build_decryption_materials_cache_key(
partition=ccmm.partition_name,
request=DecryptionMaterialsRequest(
algorithm=algorithm,
encrypted_data_keys=header.encrypted_data_keys,
encryption_context=header.encryption_context,
),
)
assert len(cache._cache) == 1
assert cache._cache[encrypt_cache_key].messages_encrypted == 1
assert cache._cache[encrypt_cache_key].bytes_encrypted == 128
_, _ = aws_encryption_sdk.decrypt(source=ciphertext, materials_manager=ccmm)
assert len(cache._cache) == 2
assert decrypt_cache_key in cache._cache
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
assert len(cache._cache) == 2
assert cache._cache[encrypt_cache_key].messages_encrypted == 4
assert cache._cache[encrypt_cache_key].bytes_encrypted == 512
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
_, _ = aws_encryption_sdk.encrypt(**encrypt_kwargs)
assert len(cache._cache) == 2
assert cache._cache[encrypt_cache_key].messages_encrypted == 2
assert cache._cache[encrypt_cache_key].bytes_encrypted == 256
def _read_header(self):
"""Reads the message header from the input stream.
:returns: tuple containing deserialized header and header_auth objects
:rtype: tuple of aws_encryption_sdk.structures.MessageHeader
and aws_encryption_sdk.internal.structures.MessageHeaderAuthentication
:raises CustomMaximumValueExceeded: if frame length is greater than the custom max value
"""
header, raw_header = aws_encryption_sdk.internal.formatting.deserialize.deserialize_header(self.source_stream)
if (
self.config.max_body_length is not None
and header.content_type == ContentType.FRAMED_DATA
and header.frame_length > self.config.max_body_length
):
raise CustomMaximumValueExceeded(
'Frame Size in header found larger than custom value: {found} > {custom}'.format(
found=header.frame_length,
custom=self.config.max_body_length
)
)
decrypt_materials_request = DecryptionMaterialsRequest(
encrypted_data_keys=header.encrypted_data_keys,
algorithm=header.algorithm,
encryption_context=header.encryption_context
)
decryption_materials = self.config.materials_manager.decrypt_materials(request=decrypt_materials_request)
if decryption_materials.verification_key is None:
self.verifier = None
else:
self.verifier = Verifier.from_key_bytes(
algorithm=header.algorithm,
key_bytes=decryption_materials.verification_key
)
if self.verifier is not None:
self.verifier.update(raw_header)
header_auth = aws_encryption_sdk.internal.formatting.deserialize.deserialize_header_auth(
stream=self.source_stream,
algorithm=header.algorithm,
verifier=self.verifier
)
self._derived_data_key = derive_data_encryption_key(
source_key=decryption_materials.data_key.data_key,
algorithm=header.algorithm,
message_id=header.message_id
)
aws_encryption_sdk.internal.formatting.deserialize.validate_header(
header=header,
header_auth=header_auth,
raw_header=raw_header,
data_key=self._derived_data_key
)
return header, header_auth
def test_decrypt_with_keyring_materials_do_not_match_request(
kwargs, algorithm_suite):
raw_aes256_keyring = ephemeral_raw_aes_keyring(
WrappingAlgorithm.AES_256_GCM_IV12_TAG16_NO_PADDING)
encrypt_cmm = DefaultCryptoMaterialsManager(keyring=raw_aes256_keyring)
decrypt_cmm = DefaultCryptoMaterialsManager(
keyring=BrokenKeyring(inner_keyring=raw_aes256_keyring, **kwargs))
encryption_materials_request = EncryptionMaterialsRequest(
encryption_context={}, frame_length=1024, algorithm=algorithm_suite)
encryption_materials = encrypt_cmm.get_encryption_materials(
encryption_materials_request)
decryption_materials_request = DecryptionMaterialsRequest(
algorithm=encryption_materials.algorithm,
encrypted_data_keys=encryption_materials.encrypted_data_keys,
encryption_context=encryption_materials.encryption_context,
)
with pytest.raises(InvalidCryptographicMaterialsError) as excinfo:
decrypt_cmm.decrypt_materials(decryption_materials_request)
excinfo.match("Decryption materials do not match request!")
(set([VALUES['basic']['encrypted_data_keys'][1]['key']
]), [VALUES['basic']['encrypted_data_keys'][1]['hash']]), ([
VALUES['basic']['encrypted_data_keys'][1]['key'],
VALUES['basic']['encrypted_data_keys'][0]['key']
], [
VALUES['basic']['encrypted_data_keys'][0]['hash'],
VALUES['basic']['encrypted_data_keys'][1]['hash']
])))
def test_encrypted_data_keys_hash(encrypted_data_keys, result):
hasher = hashes.Hash(hashes.SHA512(), backend=default_backend())
assert _encrypted_data_keys_hash(hasher, encrypted_data_keys) == b''.join(
[b64decode(each) for each in result])
@pytest.mark.parametrize(
'inner_request, result', [(dict(
partition=scenario['components']['partition_name'],
request=DecryptionMaterialsRequest(
algorithm=scenario['components']['algorithm'],
encrypted_data_keys=scenario['components']['encrypted_data_keys'],
encryption_context=scenario['components']['encryption_context'])),
scenario['id'])
for scenario in VALUES['cache_ids']['decrypt']])
def test_build_decryption_materials_cache_key(inner_request, result):
assert build_decryption_materials_cache_key(
**inner_request) == b64decode(result)
def test_512_bit_pad():
assert _512_BIT_PAD == struct.pack('>64x')
)
def test_encrypted_data_keys_hash(encrypted_data_keys, result):
hasher = hashes.Hash(hashes.SHA512(), backend=default_backend())
assert _encrypted_data_keys_hash(hasher, encrypted_data_keys) == b"".join(
[b64decode(each) for each in result])
@pytest.mark.parametrize(
"inner_request, result",
[(
dict(
partition=scenario["components"]["partition_name"],
request=DecryptionMaterialsRequest(
algorithm=scenario["components"]["algorithm"],
encrypted_data_keys=scenario["components"]
["encrypted_data_keys"],
encryption_context=scenario["components"]
["encryption_context"],
commitment_policy=scenario["components"]["commitment_policy"],
),
),
scenario["id"],
) for scenario in VALUES["cache_ids"]["decrypt"]],
)
def test_build_decryption_materials_cache_key(inner_request, result):
assert build_decryption_materials_cache_key(
**inner_request) == b64decode(result)
def test_512_bit_pad():
assert _512_BIT_PAD == struct.pack(">64x")
def _read_header(self):
"""Reads the message header from the input stream.
:returns: tuple containing deserialized header and header_auth objects
:rtype: tuple of aws_encryption_sdk.structures.MessageHeader
and aws_encryption_sdk.internal.structures.MessageHeaderAuthentication
:raises CustomMaximumValueExceeded: if frame length is greater than the custom max value
"""
header, raw_header = deserialize_header(self.source_stream)
self.__unframed_bytes_read += len(raw_header)
validate_commitment_policy_on_decrypt(self.config.commitment_policy,
header.algorithm)
if (self.config.max_body_length is not None
and header.content_type == ContentType.FRAMED_DATA
and header.frame_length > self.config.max_body_length):
raise CustomMaximumValueExceeded(
"Frame Size in header found larger than custom value: {found:d} > {custom:d}"
.format(found=header.frame_length,
custom=self.config.max_body_length))
decrypt_materials_request = DecryptionMaterialsRequest(
encrypted_data_keys=header.encrypted_data_keys,
algorithm=header.algorithm,
encryption_context=header.encryption_context,
commitment_policy=self.config.commitment_policy,
)
decryption_materials = self.config.materials_manager.decrypt_materials(
request=decrypt_materials_request)
if decryption_materials.verification_key is None:
self.verifier = None
else:
self.verifier = Verifier.from_key_bytes(
algorithm=header.algorithm,
key_bytes=decryption_materials.verification_key)
if self.verifier is not None:
self.verifier.update(raw_header)
header_auth = deserialize_header_auth(version=header.version,
stream=self.source_stream,
algorithm=header.algorithm,
verifier=self.verifier)
self._derived_data_key = derive_data_encryption_key(
source_key=decryption_materials.data_key.data_key,
algorithm=header.algorithm,
message_id=header.message_id)
if header.algorithm.is_committing():
expected_commitment_key = calculate_commitment_key(
source_key=decryption_materials.data_key.data_key,
algorithm=header.algorithm,
message_id=header.message_id,
)
if not hmac.compare_digest(expected_commitment_key,
header.commitment_key):
raise MasterKeyProviderError(
"Key commitment validation failed. Key identity does not match the identity asserted in the "
"message. Halting processing of this message.")
validate_header(header=header,
header_auth=header_auth,
raw_header=raw_header,
data_key=self._derived_data_key)
return header, header_auth
