mirror of https://git.matrix.org/git/olm.git
93 lines
3.0 KiB
C
93 lines
3.0 KiB
C
/* Copyright 2016 OpenMarket Ltd
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#include "olm/pickle_encoding.h"
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#include "olm/base64.h"
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#include "olm/cipher.h"
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#include "olm/olm.h"
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static const struct _olm_cipher_aes_sha_256 PICKLE_CIPHER =
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OLM_CIPHER_INIT_AES_SHA_256("Pickle");
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size_t _olm_enc_output_length(
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size_t raw_length
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) {
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const struct _olm_cipher *cipher = OLM_CIPHER_BASE(&PICKLE_CIPHER);
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size_t length = cipher->ops->encrypt_ciphertext_length(cipher, raw_length);
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length += cipher->ops->mac_length(cipher);
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return _olm_encode_base64_length(length);
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}
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uint8_t * _olm_enc_output_pos(
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uint8_t * output,
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size_t raw_length
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) {
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const struct _olm_cipher *cipher = OLM_CIPHER_BASE(&PICKLE_CIPHER);
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size_t length = cipher->ops->encrypt_ciphertext_length(cipher, raw_length);
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length += cipher->ops->mac_length(cipher);
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return output + _olm_encode_base64_length(length) - length;
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}
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size_t _olm_enc_output(
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uint8_t const * key, size_t key_length,
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uint8_t * output, size_t raw_length
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) {
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const struct _olm_cipher *cipher = OLM_CIPHER_BASE(&PICKLE_CIPHER);
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size_t ciphertext_length = cipher->ops->encrypt_ciphertext_length(
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cipher, raw_length
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);
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size_t length = ciphertext_length + cipher->ops->mac_length(cipher);
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size_t base64_length = _olm_encode_base64_length(length);
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uint8_t * raw_output = output + base64_length - length;
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cipher->ops->encrypt(
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cipher,
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key, key_length,
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raw_output, raw_length,
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raw_output, ciphertext_length,
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raw_output, length
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);
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_olm_encode_base64(raw_output, length, output);
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return base64_length;
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}
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size_t _olm_enc_input(uint8_t const * key, size_t key_length,
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uint8_t * input, size_t b64_length,
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enum OlmErrorCode * last_error
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) {
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size_t enc_length = _olm_decode_base64_length(b64_length);
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if (enc_length == (size_t)-1) {
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if (last_error) {
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*last_error = OLM_INVALID_BASE64;
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}
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return (size_t)-1;
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}
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_olm_decode_base64(input, b64_length, input);
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const struct _olm_cipher *cipher = OLM_CIPHER_BASE(&PICKLE_CIPHER);
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size_t raw_length = enc_length - cipher->ops->mac_length(cipher);
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size_t result = cipher->ops->decrypt(
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cipher,
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key, key_length,
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input, enc_length,
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input, raw_length,
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input, raw_length
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);
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if (result == (size_t)-1 && last_error) {
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*last_error = OLM_BAD_ACCOUNT_KEY;
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}
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return result;
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}
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