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/*
* Copyright (C) 2013 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* 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
*/
/**
* @file
* @ingroup lavu_hash_generic
* Generic hashing API
*/
#ifndef AVUTIL_HASH_H
#define AVUTIL_HASH_H
#include <stdint.h>
/**
* @defgroup lavu_hash Hash Functions
* @ingroup lavu_crypto
*
* @{
*
* @defgroup lavu_hash_generic Generic Hashing API
*
* @{
*/
struct AVHashContext;
/**
* Allocate a hash context for the algorithm specified by name.
*
* @return >= 0 for success, a negative error code for failure
* @note The context is not initialized, you must call av_hash_init().
*/
int av_hash_alloc(struct AVHashContext **ctx, const char *name);
/**
* Get the names of available hash algorithms.
*
* This function can be used to enumerate the algorithms.
*
* @param i index of the hash algorithm, starting from 0
* @return a pointer to a static string or NULL if i is out of range
*/
const char *av_hash_names(int i);
/**
* Get the name of the algorithm corresponding to the given hash context.
*/
const char *av_hash_get_name(const struct AVHashContext *ctx);
/**
* Maximum value that av_hash_get_size will currently return.
*
* You can use this if you absolutely want or need to use static allocation
* and are fine with not supporting hashes newly added to libavutil without
* recompilation.
* Note that you still need to check against av_hash_get_size, adding new hashes
* with larger sizes will not be considered an ABI change and should not cause
* your code to overflow a buffer.
*/
#define AV_HASH_MAX_SIZE 64
/**
* Get the size of the resulting hash value in bytes.
*
* The pointer passed to av_hash_final have space for at least this many bytes.
*/
int av_hash_get_size(const struct AVHashContext *ctx);
/**
* Initialize or reset a hash context.
*/
void av_hash_init(struct AVHashContext *ctx);
/**
* Update a hash context with additional data.
*/
void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len);
/**
* Finalize a hash context and compute the actual hash value.
*/
void av_hash_final(struct AVHashContext *ctx, uint8_t *dst);
/**
* Finalize a hash context and compute the actual hash value.
* If size is smaller than the hash size, the hash is truncated;
* if size is larger, the buffer is padded with 0.
*/
void av_hash_final_bin(struct AVHashContext *ctx, uint8_t *dst, int size);
/**
* Finalize a hash context and compute the actual hash value as a hex string.
* The string is always 0-terminated.
* If size is smaller than 2 * hash_size + 1, the hex string is truncated.
*/
void av_hash_final_hex(struct AVHashContext *ctx, uint8_t *dst, int size);
/**
* Finalize a hash context and compute the actual hash value as a base64 string.
* The string is always 0-terminated.
* If size is smaller than AV_BASE64_SIZE(hash_size), the base64 string is
* truncated.
*/
void av_hash_final_b64(struct AVHashContext *ctx, uint8_t *dst, int size);
/**
* Free hash context.
*/
void av_hash_freep(struct AVHashContext **ctx);
/**
* @}
* @}
*/
#endif /* AVUTIL_HASH_H */
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