ffmpeg/libavutil/hmac.c

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/*
* 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
*/
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include "attributes.h"
#include "hmac.h"
#include "md5.h"
#include "sha.h"
#include "sha512.h"
#include "mem.h"
#include "version.h"
#define MAX_HASHLEN 64
#define MAX_BLOCKLEN 128
typedef void (*hmac_final)(void *ctx, uint8_t *dst);
#if FF_API_CRYPTO_SIZE_T
typedef void (*hmac_update)(void *ctx, const uint8_t *src, int len);
#else
typedef void (*hmac_update)(void *ctx, const uint8_t *src, size_t len);
#endif
typedef void (*hmac_init)(void *ctx);
struct AVHMAC {
void *hash;
int blocklen, hashlen;
hmac_final final;
hmac_update update;
hmac_init init;
uint8_t key[MAX_BLOCKLEN];
int keylen;
};
#define DEFINE_SHA(bits) \
static av_cold void sha ## bits ##_init(void *ctx) \
{ \
av_sha_init(ctx, bits); \
}
#define DEFINE_SHA512(bits) \
static av_cold void sha ## bits ##_init(void *ctx) \
{ \
av_sha512_init(ctx, bits); \
}
DEFINE_SHA(160)
DEFINE_SHA(224)
DEFINE_SHA(256)
DEFINE_SHA512(384)
DEFINE_SHA512(512)
AVHMAC *av_hmac_alloc(enum AVHMACType type)
{
AVHMAC *c = av_mallocz(sizeof(*c));
if (!c)
return NULL;
switch (type) {
case AV_HMAC_MD5:
c->blocklen = 64;
c->hashlen = 16;
c->init = (hmac_init) av_md5_init;
c->update = (hmac_update) av_md5_update;
c->final = (hmac_final) av_md5_final;
c->hash = av_md5_alloc();
break;
case AV_HMAC_SHA1:
c->blocklen = 64;
c->hashlen = 20;
c->init = sha160_init;
c->update = (hmac_update) av_sha_update;
c->final = (hmac_final) av_sha_final;
c->hash = av_sha_alloc();
break;
case AV_HMAC_SHA224:
c->blocklen = 64;
c->hashlen = 28;
c->init = sha224_init;
c->update = (hmac_update) av_sha_update;
c->final = (hmac_final) av_sha_final;
c->hash = av_sha_alloc();
break;
case AV_HMAC_SHA256:
c->blocklen = 64;
c->hashlen = 32;
c->init = sha256_init;
c->update = (hmac_update) av_sha_update;
c->final = (hmac_final) av_sha_final;
c->hash = av_sha_alloc();
break;
case AV_HMAC_SHA384:
c->blocklen = 128;
c->hashlen = 48;
c->init = sha384_init;
c->update = (hmac_update) av_sha512_update;
c->final = (hmac_final) av_sha512_final;
c->hash = av_sha512_alloc();
break;
case AV_HMAC_SHA512:
c->blocklen = 128;
c->hashlen = 64;
c->init = sha512_init;
c->update = (hmac_update) av_sha512_update;
c->final = (hmac_final) av_sha512_final;
c->hash = av_sha512_alloc();
break;
default:
av_free(c);
return NULL;
}
if (!c->hash) {
av_free(c);
return NULL;
}
return c;
}
void av_hmac_free(AVHMAC *c)
{
if (!c)
return;
av_freep(&c->hash);
av_free(c);
}
void av_hmac_init(AVHMAC *c, const uint8_t *key, unsigned int keylen)
{
int i;
uint8_t block[MAX_BLOCKLEN];
if (keylen > c->blocklen) {
c->init(c->hash);
c->update(c->hash, key, keylen);
c->final(c->hash, c->key);
c->keylen = c->hashlen;
} else {
memcpy(c->key, key, keylen);
c->keylen = keylen;
}
c->init(c->hash);
for (i = 0; i < c->keylen; i++)
block[i] = c->key[i] ^ 0x36;
for (i = c->keylen; i < c->blocklen; i++)
block[i] = 0x36;
c->update(c->hash, block, c->blocklen);
}
void av_hmac_update(AVHMAC *c, const uint8_t *data, unsigned int len)
{
c->update(c->hash, data, len);
}
int av_hmac_final(AVHMAC *c, uint8_t *out, unsigned int outlen)
{
uint8_t block[MAX_BLOCKLEN];
int i;
if (outlen < c->hashlen)
return AVERROR(EINVAL);
c->final(c->hash, out);
c->init(c->hash);
for (i = 0; i < c->keylen; i++)
block[i] = c->key[i] ^ 0x5C;
for (i = c->keylen; i < c->blocklen; i++)
block[i] = 0x5C;
c->update(c->hash, block, c->blocklen);
c->update(c->hash, out, c->hashlen);
c->final(c->hash, out);
return c->hashlen;
}
int av_hmac_calc(AVHMAC *c, const uint8_t *data, unsigned int len,
const uint8_t *key, unsigned int keylen,
uint8_t *out, unsigned int outlen)
{
av_hmac_init(c, key, keylen);
av_hmac_update(c, data, len);
return av_hmac_final(c, out, outlen);
}