Merge branch 'master' into poljar/python-sas

This commit is contained in:
Hubert Chathi 2019-04-08 15:08:17 -04:00 committed by GitHub
commit 2a6400716c
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
11 changed files with 574 additions and 5 deletions

View file

@ -0,0 +1,100 @@
/*
* Copyright 2019 New Vector Ltd
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.matrix.olm;
import android.util.Log;
import java.util.Arrays;
public class OlmPkSigning {
private static final String LOG_TAG = "OlmPkSigning";
/** PK Signing Id returned by JNI.
* This value uniquely identifies the native PK signing instance.
**/
private transient long mNativeId;
public OlmPkSigning() throws OlmException {
try {
mNativeId = createNewPkSigningJni();
} catch (Exception e) {
throw new OlmException(OlmException.EXCEPTION_CODE_PK_SIGNING_CREATION, e.getMessage());
}
}
private native long createNewPkSigningJni();
private native void releasePkSigningJni();
public void releaseSigning() {
if (0 != mNativeId) {
releasePkSigningJni();
}
mNativeId = 0;
}
public boolean isReleased() {
return (0 == mNativeId);
}
public static native int seedLength();
public static byte[] generateSeed() throws OlmException {
try {
return generateSeedJni();
} catch (Exception e) {
Log.e(LOG_TAG, "## generateSeed(): failed " + e.getMessage());
throw new OlmException(OlmException.EXCEPTION_CODE_PK_SIGNING_GENERATE_SEED, e.getMessage());
}
}
public static native byte[] generateSeedJni();
public String initWithSeed(byte[] seed) throws OlmException {
try {
byte[] pubKey = setKeyFromSeedJni(seed);
return new String(pubKey, "UTF-8");
} catch (Exception e) {
Log.e(LOG_TAG, "## initWithSeed(): failed " + e.getMessage());
throw new OlmException(OlmException.EXCEPTION_CODE_PK_SIGNING_INIT_WITH_SEED, e.getMessage());
}
}
public native byte[] setKeyFromSeedJni(byte[] seed);
public String sign(String aMessage) throws OlmException {
if (null == aMessage) {
return null;
}
byte[] messageBuffer = null;
try {
messageBuffer = aMessage.getBytes("UTF-8");
byte[] signature = pkSignJni(messageBuffer);
return new String(signature, "UTF-8");
} catch (Exception e) {
Log.e(LOG_TAG, "## pkSign(): failed " + e.getMessage());
throw new OlmException(OlmException.EXCEPTION_CODE_PK_SIGNING_SIGN, e.getMessage());
} finally {
if (null != messageBuffer) {
Arrays.fill(messageBuffer, (byte) 0);
}
}
}
private native byte[] pkSignJni(byte[] message);
}

View file

@ -147,6 +147,14 @@ size_t olm_sas_calculate_mac(
void * mac, size_t mac_length
);
// for compatibility with an old version of Riot
size_t olm_sas_calculate_mac_long_kdf(
OlmSAS * sas,
void * input, size_t input_length,
const void * info, size_t info_length,
void * mac, size_t mac_length
);
/** @} */ // end of SAS group
#ifdef __cplusplus

View file

@ -75,3 +75,19 @@ SAS.prototype['calculate_mac'] = restore_stack(function(input, info) {
);
return Pointer_stringify(mac_buffer);
});
SAS.prototype['calculate_mac_long_kdf'] = restore_stack(function(input, info) {
var input_array = array_from_string(input);
var input_buffer = stack(input_array);
var info_array = array_from_string(info);
var info_buffer = stack(info_array);
var mac_length = sas_method(Module['_olm_sas_mac_length'])(this.ptr);
var mac_buffer = stack(mac_length + NULL_BYTE_PADDING_LENGTH);
sas_method(Module['_olm_sas_calculate_mac_long_kdf'])(
this.ptr,
input_buffer, input_array.length,
info_buffer, info_array.length,
mac_buffer, mac_length
);
return Pointer_stringify(mac_buffer);
});

View file

@ -1,3 +1,4 @@
include olm.h
include include/olm/olm.h
include include/olm/pk.h
include Makefile
include olm_build.py

View file

@ -1,18 +1,26 @@
all: olm-python2 olm-python3
include/olm/olm.h: ../include/olm/olm.h ../include/olm/inbound_group_session.h ../include/olm/outbound_group_session.h
OLM_HEADERS = ../include/olm/olm.h ../include/olm/inbound_group_session.h \
../include/olm/outbound_group_session.h \
include/olm/olm.h: $(OLM_HEADERS)
mkdir -p include/olm
$(CPP) -I dummy -I ../include ../include/olm/olm.h -o include/olm/olm.h
# add memset to the header so that we can use it to clear buffers
echo 'void *memset(void *s, int c, size_t n);' >> include/olm/olm.h
include/olm/pk.h: include/olm/olm.h ../include/olm/pk.h
$(CPP) -I dummy -I ../include ../include/olm/pk.h -o include/olm/pk.h
include/olm/sas.h: include/olm/olm.h ../include/olm/sas.h
$(CPP) -I dummy -I ../include ../include/olm/sas.h -o include/olm/sas.h
olm-python2: include/olm/olm.h include/olm/sas.h
headers: include/olm/olm.h include/olm/pk.h include/olm/sas.h
olm-python2: headers
DEVELOP=$(DEVELOP) python2 setup.py build
olm-python3: include/olm/olm.h include/olm/sas.h
olm-python3: headers
DEVELOP=$(DEVELOP) python3 setup.py build
install: install-python2 install-python3

View file

@ -36,4 +36,11 @@ from .group_session import (
OutboundGroupSession,
OlmGroupSessionError
)
from .pk import (
PkMessage,
PkEncryption,
PkDecryption,
PkEncryptionError,
PkDecryptionError
)
from .sas import Sas, OlmSasError

346
python/olm/pk.py Normal file
View file

@ -0,0 +1,346 @@
# -*- coding: utf-8 -*-
# libolm python bindings
# Copyright © 2018 Damir Jelić <poljar@termina.org.uk>
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""libolm PK module.
This module contains bindings to the PK part of the Olm library.
It contains two classes PkDecryption and PkEncryption that are used to
establish an encrypted communication channel using public key encryption.
Examples:
>>> decryption = PkDecryption()
>>> encryption = PkEncryption(decryption.public_key)
>>> plaintext = "It's a secret to everybody."
>>> message = encryption.encrypt(plaintext)
>>> decrypted_plaintext = decryption.decrypt(message)
"""
from builtins import super
from typing import AnyStr, Type
from future.utils import bytes_to_native_str
from _libolm import ffi, lib # type: ignore
from ._finalize import track_for_finalization
from ._compat import URANDOM, to_bytearray
class PkEncryptionError(Exception):
"""libolm Pk encryption exception."""
class PkDecryptionError(Exception):
"""libolm Pk decryption exception."""
def _clear_pk_encryption(pk_struct):
lib.olm_clear_pk_encryption(pk_struct)
class PkMessage(object):
"""A PK encrypted message."""
def __init__(self, ephemeral_key, mac, ciphertext):
# type: (str, str, str) -> None
"""Create a new PK encrypted message.
Args:
ephemeral_key(str): the public part of the ephemeral key
used (together with the recipient's key) to generate a symmetric
encryption key.
mac(str): Message Authentication Code of the encrypted message
ciphertext(str): The cipher text of the encrypted message
"""
self.ephemeral_key = ephemeral_key
self.mac = mac
self.ciphertext = ciphertext
class PkEncryption(object):
"""PkEncryption class.
Represents the decryption part of a PK encrypted channel.
"""
def __init__(self, recipient_key):
# type: (AnyStr) -> None
"""Create a new PK encryption object.
Args:
recipient_key(str): a public key that will be used for encryption
"""
if not recipient_key:
raise ValueError("Recipient key can't be empty")
self._buf = ffi.new("char[]", lib.olm_pk_encryption_size())
self._pk_encryption = lib.olm_pk_encryption(self._buf)
track_for_finalization(self, self._pk_encryption, _clear_pk_encryption)
byte_key = to_bytearray(recipient_key)
lib.olm_pk_encryption_set_recipient_key(
self._pk_encryption,
ffi.from_buffer(byte_key),
len(byte_key)
)
# clear out copies of the key
if byte_key is not recipient_key: # pragma: no cover
for i in range(0, len(byte_key)):
byte_key[i] = 0
def _check_error(self, ret): # pragma: no cover
# type: (int) -> None
if ret != lib.olm_error():
return
last_error = bytes_to_native_str(
ffi.string(lib.olm_pk_encryption_last_error(self._pk_encryption)))
raise PkEncryptionError(last_error)
def encrypt(self, plaintext):
# type: (AnyStr) -> PkMessage
"""Encrypt a message.
Returns the encrypted PkMessage.
Args:
plaintext(str): A string that will be encrypted using the
PkEncryption object.
"""
byte_plaintext = to_bytearray(plaintext)
r_length = lib.olm_pk_encrypt_random_length(self._pk_encryption)
random = URANDOM(r_length)
random_buffer = ffi.new("char[]", random)
ciphertext_length = lib.olm_pk_ciphertext_length(
self._pk_encryption, len(byte_plaintext)
)
ciphertext = ffi.new("char[]", ciphertext_length)
mac_length = lib.olm_pk_mac_length(self._pk_encryption)
mac = ffi.new("char[]", mac_length)
ephemeral_key_size = lib.olm_pk_key_length()
ephemeral_key = ffi.new("char[]", ephemeral_key_size)
ret = lib.olm_pk_encrypt(
self._pk_encryption,
ffi.from_buffer(byte_plaintext), len(byte_plaintext),
ciphertext, ciphertext_length,
mac, mac_length,
ephemeral_key, ephemeral_key_size,
random_buffer, r_length
)
try:
self._check_error(ret)
finally: # pragma: no cover
# clear out copies of plaintext
if byte_plaintext is not plaintext:
for i in range(0, len(byte_plaintext)):
byte_plaintext[i] = 0
message = PkMessage(
bytes_to_native_str(
ffi.unpack(ephemeral_key, ephemeral_key_size)),
bytes_to_native_str(
ffi.unpack(mac, mac_length)),
bytes_to_native_str(
ffi.unpack(ciphertext, ciphertext_length))
)
return message
def _clear_pk_decryption(pk_struct):
lib.olm_clear_pk_decryption(pk_struct)
class PkDecryption(object):
"""PkDecryption class.
Represents the decryption part of a PK encrypted channel.
Attributes:
public_key (str): The public key of the PkDecryption object, can be
shared and used to create a PkEncryption object.
"""
def __new__(cls):
# type: (Type[PkDecryption]) -> PkDecryption
obj = super().__new__(cls)
obj._buf = ffi.new("char[]", lib.olm_pk_decryption_size())
obj._pk_decryption = lib.olm_pk_decryption(obj._buf)
obj.public_key = None
track_for_finalization(obj, obj._pk_decryption, _clear_pk_decryption)
return obj
def __init__(self):
if False: # pragma: no cover
self._pk_decryption = self._pk_decryption # type: ffi.cdata
random_length = lib.olm_pk_private_key_length()
random = URANDOM(random_length)
random_buffer = ffi.new("char[]", random)
key_length = lib.olm_pk_key_length()
key_buffer = ffi.new("char[]", key_length)
ret = lib.olm_pk_key_from_private(
self._pk_decryption,
key_buffer, key_length,
random_buffer, random_length
)
self._check_error(ret)
self.public_key = bytes_to_native_str(ffi.unpack(
key_buffer,
key_length
))
def _check_error(self, ret):
# type: (int) -> None
if ret != lib.olm_error():
return
last_error = bytes_to_native_str(
ffi.string(lib.olm_pk_decryption_last_error(self._pk_decryption)))
raise PkDecryptionError(last_error)
def pickle(self, passphrase=""):
# type: (str) -> bytes
"""Store a PkDecryption object.
Stores a PkDecryption object as a base64 string. Encrypts the object
using the supplied passphrase. Returns a byte object containing the
base64 encoded string of the pickled session.
Args:
passphrase(str, optional): The passphrase to be used to encrypt
the object.
"""
byte_key = to_bytearray(passphrase)
pickle_length = lib.olm_pickle_pk_decryption_length(
self._pk_decryption
)
pickle_buffer = ffi.new("char[]", pickle_length)
ret = lib.olm_pickle_pk_decryption(
self._pk_decryption,
ffi.from_buffer(byte_key), len(byte_key),
pickle_buffer, pickle_length
)
try:
self._check_error(ret)
finally:
# zero out copies of the passphrase
for i in range(0, len(byte_key)):
byte_key[i] = 0
return ffi.unpack(pickle_buffer, pickle_length)
@classmethod
def from_pickle(cls, pickle, passphrase=""):
# types: (bytes, str) -> PkDecryption
"""Restore a previously stored PkDecryption object.
Creates a PkDecryption object from a pickled base64 string. Decrypts
the pickled object using the supplied passphrase.
Raises PkDecryptionError on failure. If the passphrase
doesn't match the one used to encrypt the session then the error
message for the exception will be "BAD_ACCOUNT_KEY". If the base64
couldn't be decoded then the error message will be "INVALID_BASE64".
Args:
pickle(bytes): Base64 encoded byte string containing the pickled
PkDecryption object
passphrase(str, optional): The passphrase used to encrypt the
object
"""
if not pickle:
raise ValueError("Pickle can't be empty")
byte_key = to_bytearray(passphrase)
pickle_buffer = ffi.new("char[]", pickle)
pubkey_length = lib.olm_pk_key_length()
pubkey_buffer = ffi.new("char[]", pubkey_length)
obj = cls.__new__(cls)
ret = lib.olm_unpickle_pk_decryption(
obj._pk_decryption,
ffi.from_buffer(byte_key), len(byte_key),
pickle_buffer, len(pickle),
pubkey_buffer, pubkey_length)
try:
obj._check_error(ret)
finally:
for i in range(0, len(byte_key)):
byte_key[i] = 0
obj.public_key = bytes_to_native_str(ffi.unpack(
pubkey_buffer,
pubkey_length
))
return obj
def decrypt(self, message):
# type (PkMessage) -> str
"""Decrypt a previously encrypted Pk message.
Returns the decrypted plaintext.
Raises PkDecryptionError on failure.
Args:
message(PkMessage): the pk message to decrypt.
"""
ephemeral_key = to_bytearray(message.ephemeral_key)
ephemeral_key_size = len(ephemeral_key)
mac = to_bytearray(message.mac)
mac_length = len(mac)
ciphertext = to_bytearray(message.ciphertext)
ciphertext_length = len(ciphertext)
max_plaintext_length = lib.olm_pk_max_plaintext_length(
self._pk_decryption,
ciphertext_length
)
plaintext_buffer = ffi.new("char[]", max_plaintext_length)
ret = lib.olm_pk_decrypt(
self._pk_decryption,
ffi.from_buffer(ephemeral_key), ephemeral_key_size,
ffi.from_buffer(mac), mac_length,
ffi.from_buffer(ciphertext), ciphertext_length,
plaintext_buffer, max_plaintext_length)
self._check_error(ret)
plaintext = (ffi.unpack(
plaintext_buffer,
ret
))
# clear out copies of the plaintext
lib.memset(plaintext_buffer, 0, max_plaintext_length)
return bytes_to_native_str(plaintext)

View file

@ -18,6 +18,7 @@
from __future__ import unicode_literals
import os
import subprocess
from cffi import FFI
@ -32,6 +33,8 @@ link_args = ["-L../build"]
if DEVELOP and DEVELOP.lower() in ["yes", "true", "1"]:
link_args.append('-Wl,-rpath=../build')
headers_build = subprocess.Popen("make headers", shell=True)
headers_build.wait()
ffibuilder.set_source(
"_libolm",
@ -39,6 +42,7 @@ ffibuilder.set_source(
#include <olm/olm.h>
#include <olm/inbound_group_session.h>
#include <olm/outbound_group_session.h>
#include <olm/pk.h>
#include <olm/sas.h>
""",
libraries=["olm"],
@ -48,6 +52,9 @@ ffibuilder.set_source(
with open(os.path.join(PATH, "include/olm/olm.h")) as f:
ffibuilder.cdef(f.read(), override=True)
with open(os.path.join(PATH, "include/olm/pk.h")) as f:
ffibuilder.cdef(f.read(), override=True)
with open(os.path.join(PATH, "include/olm/sas.h")) as f:
ffibuilder.cdef(f.read(), override=True)

View file

@ -22,6 +22,10 @@ setup(
packages=["olm"],
setup_requires=["cffi>=1.0.0"],
cffi_modules=["olm_build.py:ffibuilder"],
install_requires=["cffi>=1.0.0", "future", "typing"],
install_requires=[
"cffi>=1.0.0",
"future",
"typing;python_version<'3.5'"
],
zip_safe=False
)

49
python/tests/pk_test.py Normal file
View file

@ -0,0 +1,49 @@
import pytest
from olm import PkDecryption, PkDecryptionError, PkEncryption
class TestClass(object):
def test_invalid_encryption(self):
with pytest.raises(ValueError):
PkEncryption("")
def test_decrytion(self):
decryption = PkDecryption()
encryption = PkEncryption(decryption.public_key)
plaintext = "It's a secret to everybody."
message = encryption.encrypt(plaintext)
decrypted_plaintext = decryption.decrypt(message)
isinstance(decrypted_plaintext, str)
assert plaintext == decrypted_plaintext
def test_invalid_decrytion(self):
decryption = PkDecryption()
encryption = PkEncryption(decryption.public_key)
plaintext = "It's a secret to everybody."
message = encryption.encrypt(plaintext)
message.ephemeral_key = "?"
with pytest.raises(PkDecryptionError):
decryption.decrypt(message)
def test_pickling(self):
decryption = PkDecryption()
encryption = PkEncryption(decryption.public_key)
plaintext = "It's a secret to everybody."
message = encryption.encrypt(plaintext)
pickle = decryption.pickle()
unpickled = PkDecryption.from_pickle(pickle)
decrypted_plaintext = unpickled.decrypt(message)
assert plaintext == decrypted_plaintext
def test_invalid_unpickling(self):
with pytest.raises(ValueError):
PkDecryption.from_pickle("")
def test_invalid_pass_pickling(self):
decryption = PkDecryption()
pickle = decryption.pickle("Secret")
with pytest.raises(PkDecryptionError):
PkDecryption.from_pickle(pickle, "Not secret")

View file

@ -139,3 +139,26 @@ size_t olm_sas_calculate_mac(
_olm_encode_base64((const uint8_t *)mac, SHA256_OUTPUT_LENGTH, (uint8_t *)mac);
return 0;
}
// for compatibility with an old version of Riot
size_t olm_sas_calculate_mac_long_kdf(
OlmSAS * sas,
void * input, size_t input_length,
const void * info, size_t info_length,
void * mac, size_t mac_length
) {
if (mac_length < olm_sas_mac_length(sas)) {
sas->last_error = OLM_OUTPUT_BUFFER_TOO_SMALL;
return (size_t)-1;
}
uint8_t key[256];
_olm_crypto_hkdf_sha256(
sas->secret, sizeof(sas->secret),
NULL, 0,
(const uint8_t *) info, info_length,
key, 256
);
_olm_crypto_hmac_sha256(key, 256, input, input_length, mac);
_olm_encode_base64((const uint8_t *)mac, SHA256_OUTPUT_LENGTH, (uint8_t *)mac);
return 0;
}