/* * 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 */ #ifndef AVUTIL_HASH_H #define AVUTIL_HASH_H #include <stdint.h> 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 */