/*
  * Copyright (C) 2012 Martin Storsjo
  *

  * This file is part of FFmpeg.

  *

  * FFmpeg is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *

  * FFmpeg is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public

  * License along with FFmpeg; if not, write to the Free Software

  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 #ifndef AVUTIL_HMAC_H
 #define AVUTIL_HMAC_H
 
 #include <stdint.h>
 
 /**
  * @defgroup lavu_hmac HMAC
  * @ingroup lavu_crypto
  * @{
  */
 
 enum AVHMACType {
     AV_HMAC_MD5,
     AV_HMAC_SHA1,

     AV_HMAC_SHA224 = 10,
     AV_HMAC_SHA256,
     AV_HMAC_SHA384,
     AV_HMAC_SHA512,

 };
 
 typedef struct AVHMAC AVHMAC;
 
 /**
  * Allocate an AVHMAC context.
  * @param type The hash function used for the HMAC.
  */
 AVHMAC *av_hmac_alloc(enum AVHMACType type);
 
 /**
  * Free an AVHMAC context.
  * @param ctx The context to free, may be NULL
  */
 void av_hmac_free(AVHMAC *ctx);
 
 /**
  * Initialize an AVHMAC context with an authentication key.
  * @param ctx    The HMAC context
  * @param key    The authentication key
  * @param keylen The length of the key, in bytes
  */
 void av_hmac_init(AVHMAC *ctx, const uint8_t *key, unsigned int keylen);
 
 /**
  * Hash data with the HMAC.
  * @param ctx  The HMAC context
  * @param data The data to hash
  * @param len  The length of the data, in bytes
  */
 void av_hmac_update(AVHMAC *ctx, const uint8_t *data, unsigned int len);
 
 /**
  * Finish hashing and output the HMAC digest.
  * @param ctx    The HMAC context
  * @param out    The output buffer to write the digest into
  * @param outlen The length of the out buffer, in bytes
  * @return       The number of bytes written to out, or a negative error code.
  */
 int av_hmac_final(AVHMAC *ctx, uint8_t *out, unsigned int outlen);
 
 /**
  * Hash an array of data with a key.
  * @param ctx    The HMAC context
  * @param data   The data to hash
  * @param len    The length of the data, in bytes
  * @param key    The authentication key
  * @param keylen The length of the key, in bytes
  * @param out    The output buffer to write the digest into
  * @param outlen The length of the out buffer, in bytes
  * @return       The number of bytes written to out, or a negative error code.
  */
 int av_hmac_calc(AVHMAC *ctx, const uint8_t *data, unsigned int len,
                  const uint8_t *key, unsigned int keylen,
                  uint8_t *out, unsigned int outlen);
 
 /**
  * @}
  */
 
 #endif /* AVUTIL_HMAC_H */