olm/include/olm/crypto.h
2016-05-23 18:55:05 +01:00

65 lines
1.8 KiB
C

/* Copyright 2015 OpenMarket 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.
*/
/* C-compatible crpyto utility functions. At some point all of crypto.hh will
* move here.
*/
#ifndef OLM_CRYPTO_H_
#define OLM_CRYPTO_H_
#include <stdint.h>
#include <stdlib.h>
#ifdef __cplusplus
extern "C" {
#endif
const size_t SHA256_OUTPUT_LENGTH = 32;
/** Computes SHA-256 of the input. The output buffer must be a least 32
* bytes long. */
void crypto_sha256(
uint8_t const * input, size_t input_length,
uint8_t * output
);
/** HMAC: Keyed-Hashing for Message Authentication
* http://tools.ietf.org/html/rfc2104
* Computes HMAC-SHA-256 of the input for the key. The output buffer must
* be at least 32 bytes long. */
void crypto_hmac_sha256(
uint8_t const * key, size_t key_length,
uint8_t const * input, size_t input_length,
uint8_t * output
);
/** HMAC-based Key Derivation Function (HKDF)
* https://tools.ietf.org/html/rfc5869
* Derives key material from the input bytes. */
void crypto_hkdf_sha256(
uint8_t const * input, size_t input_length,
uint8_t const * info, size_t info_length,
uint8_t const * salt, size_t salt_length,
uint8_t * output, size_t output_length
);
#ifdef __cplusplus
} // extern "C"
#endif
#endif /* OLM_CRYPTO_H_ */