ffmpeg/libavutil/hash.c

155 lines
4.0 KiB
C

/*
* 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
*/
#include <stdint.h>
#include "hash.h"
#include "adler32.h"
#include "crc.h"
#include "md5.h"
#include "murmur3.h"
#include "sha.h"
#include "avstring.h"
#include "error.h"
#include "intreadwrite.h"
#include "mem.h"
enum hashtype {
MD5,
MURMUR3,
SHA160,
SHA224,
SHA256,
CRC32,
ADLER32,
NUM_HASHES
};
typedef struct AVHashContext {
void *ctx;
enum hashtype type;
const AVCRC *crctab;
uint32_t crc;
} AVHashContext;
struct {
const char *name;
int size;
} hashdesc[] = {
[MD5] = {"MD5", 16},
[MURMUR3] = {"murmur3", 16},
[SHA160] = {"SHA160", 20},
[SHA224] = {"SHA224", 28},
[SHA256] = {"SHA256", 32},
[CRC32] = {"CRC32", 4},
[ADLER32] = {"adler32", 4},
};
const char *av_hash_names(int i)
{
if (i < 0 || i >= NUM_HASHES) return NULL;
return hashdesc[i].name;
}
const char *av_hash_get_name(const AVHashContext *ctx)
{
return hashdesc[ctx->type].name;
}
int av_hash_get_size(const AVHashContext *ctx)
{
return hashdesc[ctx->type].size;
}
int av_hash_alloc(AVHashContext **ctx, const char *name)
{
AVHashContext *res;
int i;
*ctx = NULL;
for (i = 0; i < NUM_HASHES; i++)
if (av_strcasecmp(name, hashdesc[i].name) == 0)
break;
if (i >= NUM_HASHES) return AVERROR(EINVAL);
res = av_mallocz(sizeof(*res));
if (!res) return AVERROR(ENOMEM);
res->type = i;
switch (i) {
case MD5: res->ctx = av_md5_alloc(); break;
case MURMUR3: res->ctx = av_murmur3_alloc(); break;
case SHA160:
case SHA224:
case SHA256: res->ctx = av_sha_alloc(); break;
case CRC32: res->crctab = av_crc_get_table(AV_CRC_32_IEEE_LE); break;
case ADLER32: break;
}
if (i != ADLER32 && i != CRC32 && !res->ctx) {
av_free(res);
return AVERROR(ENOMEM);
}
*ctx = res;
return 0;
}
void av_hash_init(AVHashContext *ctx)
{
switch (ctx->type) {
case MD5: av_md5_init(ctx->ctx); break;
case MURMUR3: av_murmur3_init(ctx->ctx); break;
case SHA160: av_sha_init(ctx->ctx, 160); break;
case SHA224: av_sha_init(ctx->ctx, 224); break;
case SHA256: av_sha_init(ctx->ctx, 256); break;
case CRC32: ctx->crc = UINT32_MAX; break;
case ADLER32: ctx->crc = 1; break;
}
}
void av_hash_update(AVHashContext *ctx, const uint8_t *src, int len)
{
switch (ctx->type) {
case MD5: av_md5_update(ctx->ctx, src, len); break;
case MURMUR3: av_murmur3_update(ctx->ctx, src, len); break;
case SHA160:
case SHA224:
case SHA256: av_sha_update(ctx->ctx, src, len); break;
case CRC32: ctx->crc = av_crc(ctx->crctab, ctx->crc, src, len); break;
case ADLER32: ctx->crc = av_adler32_update(ctx->crc, src, len); break;
}
}
void av_hash_final(AVHashContext *ctx, uint8_t *dst)
{
switch (ctx->type) {
case MD5: av_md5_final(ctx->ctx, dst); break;
case MURMUR3: av_murmur3_final(ctx->ctx, dst); break;
case SHA160:
case SHA224:
case SHA256: av_sha_final(ctx->ctx, dst); break;
case CRC32: AV_WB32(dst, ctx->crc ^ UINT32_MAX); break;
case ADLER32: AV_WB32(dst, ctx->crc); break;
}
}
void av_hash_freep(AVHashContext **ctx)
{
if (*ctx)
av_freep(&(*ctx)->ctx);
av_freep(ctx);
}