diff options
Diffstat (limited to 'python')
| -rw-r--r-- | python/olm/__init__.py | 2 | ||||
| -rw-r--r-- | python/olm/utility.py | 57 | ||||
| -rw-r--r-- | python/tests/utils_test.py | 29 |
3 files changed, 78 insertions, 10 deletions
diff --git a/python/olm/__init__.py b/python/olm/__init__.py index fe3e199..9ac45b0 100644 --- a/python/olm/__init__.py +++ b/python/olm/__init__.py @@ -21,7 +21,7 @@ Olm Python bindings | © Copyright 2015-2017 by OpenMarket Ltd | © Copyright 2018 by Damir Jelić """ -from .utility import ed25519_verify, OlmVerifyError +from .utility import ed25519_verify, OlmVerifyError, OlmHashError, sha256 from .account import Account, OlmAccountError from .session import ( Session, diff --git a/python/olm/utility.py b/python/olm/utility.py index 121ff63..10d5ab4 100644 --- a/python/olm/utility.py +++ b/python/olm/utility.py @@ -32,6 +32,7 @@ Examples: # pylint: disable=redefined-builtin,unused-import from typing import AnyStr, Type +from future.utils import bytes_to_native_str # pylint: disable=no-name-in-module from _libolm import ffi, lib # type: ignore @@ -49,6 +50,10 @@ class OlmVerifyError(Exception): """libolm signature verification exception.""" +class OlmHashError(Exception): + """libolm hash calculation exception.""" + + class _Utility(object): # pylint: disable=too-few-public-methods """libolm Utility class.""" @@ -64,12 +69,12 @@ class _Utility(object): track_for_finalization(cls, cls._utility, _clear_utility) @classmethod - def _check_error(cls, ret): - # type: (int) -> None + def _check_error(cls, ret, error_class): + # type: (int, Type) -> None if ret != lib.olm_error(): return - raise OlmVerifyError("{}".format( + raise error_class("{}".format( ffi.string(lib.olm_utility_last_error( cls._utility)).decode("utf-8"))) @@ -84,18 +89,41 @@ class _Utility(object): byte_signature = to_bytearray(signature) try: - cls._check_error( - lib.olm_ed25519_verify(cls._utility, byte_key, len(byte_key), - ffi.from_buffer(byte_message), - len(byte_message), - ffi.from_buffer(byte_signature), - len(byte_signature))) + ret = lib.olm_ed25519_verify( + cls._utility, + byte_key, + len(byte_key), + ffi.from_buffer(byte_message), + len(byte_message), + ffi.from_buffer(byte_signature), + len(byte_signature) + ) + + cls._check_error(ret, OlmVerifyError) + finally: # clear out copies of the message, which may be a plaintext if byte_message is not message: for i in range(0, len(byte_message)): byte_message[i] = 0 + @classmethod + def _sha256(cls, input): + # type: (Type[_Utility], AnyStr) -> str + if not cls._utility: + cls._allocate() + + byte_input = to_bytes(input) + hash_length = lib.olm_sha256_length(cls._utility) + hash = ffi.new("char[]", hash_length) + + ret = lib.olm_sha256(cls._utility, byte_input, len(byte_input), + hash, hash_length) + + cls._check_error(ret, OlmHashError) + + return bytes_to_native_str(ffi.unpack(hash, hash_length)) + def ed25519_verify(key, message, signature): # type: (AnyStr, AnyStr, AnyStr) -> None @@ -109,3 +137,14 @@ def ed25519_verify(key, message, signature): signature(bytes): The message signature. """ return _Utility._ed25519_verify(key, message, signature) + + +def sha256(input_string): + # type: (AnyStr) -> str + """Calculate the SHA-256 hash of the input and encodes it as base64. + + Args: + input_string(str): The input for which the hash will be calculated. + + """ + return _Utility._sha256(input_string) diff --git a/python/tests/utils_test.py b/python/tests/utils_test.py new file mode 100644 index 0000000..a552d12 --- /dev/null +++ b/python/tests/utils_test.py @@ -0,0 +1,29 @@ +import base64 +import hashlib + +from future.utils import bytes_to_native_str +from hypothesis import given +from hypothesis.strategies import text + +from olm import sha256 +from olm._compat import to_bytes + + +class TestClass(object): + @given(text(), text()) + def test_sha256(self, input1, input2): + first_hash = sha256(input1) + second_hash = sha256(input2) + + hashlib_hash = base64.b64encode( + hashlib.sha256(to_bytes(input1)).digest() + ) + + hashlib_hash = bytes_to_native_str(hashlib_hash[:-1]) + + if input1 == input2: + assert first_hash == second_hash + else: + assert first_hash != second_hash + + assert hashlib_hash == first_hash |