lavu/hash: add hash_final helpers.

The helpers use local memory to compute the final hash,
making AV_HASH_MAX_SIZE safe to use.
This commit is contained in:
Nicolas George 2014-04-21 11:01:10 +02:00
parent 5b881499a8
commit b804eb4323
4 changed files with 61 additions and 1 deletions

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@ -15,6 +15,9 @@ libavutil: 2012-10-22
API changes, most recent first:
2014-04-29 - xxxxxxx - lavu 52.80.0 - hash.h
Add av_hash_final_bin(), av_hash_final_hex() and av_hash_final_b64().
2014-03-07 - 8b2a130 - lavc 55.50.0 / 55.53.100 - dxva2.h
Add FF_DXVA2_WORKAROUND_INTEL_CLEARVIDEO for old Intel GPUs.

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@ -29,6 +29,7 @@
#include "sha512.h"
#include "avstring.h"
#include "base64.h"
#include "error.h"
#include "intreadwrite.h"
#include "mem.h"
@ -196,6 +197,40 @@ void av_hash_final(AVHashContext *ctx, uint8_t *dst)
}
}
void av_hash_final_bin(struct AVHashContext *ctx, uint8_t *dst, int size)
{
uint8_t buf[AV_HASH_MAX_SIZE];
unsigned rsize = av_hash_get_size(ctx);
av_hash_final(ctx, buf);
memcpy(dst, buf, FFMIN(size, rsize));
if (size > rsize)
memset(dst + rsize, 0, size - rsize);
}
void av_hash_final_hex(struct AVHashContext *ctx, uint8_t *dst, int size)
{
uint8_t buf[AV_HASH_MAX_SIZE];
unsigned rsize = av_hash_get_size(ctx), i;
av_hash_final(ctx, buf);
for (i = 0; i < FFMIN(rsize, size / 2); i++)
snprintf(dst + i * 2, size - i * 2, "%02x", buf[i]);
}
void av_hash_final_b64(struct AVHashContext *ctx, uint8_t *dst, int size)
{
uint8_t buf[AV_HASH_MAX_SIZE], b64[AV_BASE64_SIZE(AV_HASH_MAX_SIZE)];
unsigned rsize = av_hash_get_size(ctx), osize;
av_hash_final(ctx, buf);
av_base64_encode(b64, sizeof(b64), buf, rsize);
osize = AV_BASE64_SIZE(rsize);
memcpy(dst, b64, FFMIN(osize, size));
if (size < osize)
dst[size - 1] = 0;
}
void av_hash_freep(AVHashContext **ctx)
{
if (*ctx)

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@ -82,6 +82,28 @@ void av_hash_update(struct AVHashContext *ctx, const uint8_t *src, int len);
*/
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.
*/

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@ -56,7 +56,7 @@
*/
#define LIBAVUTIL_VERSION_MAJOR 52
#define LIBAVUTIL_VERSION_MINOR 79
#define LIBAVUTIL_VERSION_MINOR 80
#define LIBAVUTIL_VERSION_MICRO 100
#define LIBAVUTIL_VERSION_INT AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \