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/*
* Copyright (c) 2006 - 2007 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/types.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <hmac.h>
void
HMAC_CTX_init(HMAC_CTX *ctx)
{
memset(ctx, 0, sizeof(*ctx));
}
void
HMAC_CTX_cleanup(HMAC_CTX *ctx)
{
if (ctx->buf) {
memset(ctx->buf, 0, ctx->key_length);
free(ctx->buf);
ctx->buf = NULL;
}
if (ctx->opad) {
memset(ctx->ipad, 0, ctx->key_length);
free(ctx->opad);
ctx->opad = NULL;
}
if (ctx->ipad) {
memset(ctx->ipad, 0, ctx->key_length);
free(ctx->ipad);
ctx->ipad = NULL;
}
if (ctx->ctx) {
EVP_MD_CTX_destroy(ctx->ctx);
ctx->ctx = NULL;
}
}
size_t
HMAC_size(const HMAC_CTX *ctx)
{
return EVP_MD_size(ctx->md);
}
void
HMAC_Init_ex(HMAC_CTX *ctx,
const void *key,
size_t keylen,
const EVP_MD *md,
ENGINE *engine)
{
unsigned char *p;
size_t i;
if (ctx->md != md) {
ctx->md = md;
if (ctx->buf) {
memset(ctx->buf, 0, ctx->key_length);
free (ctx->buf);
}
ctx->key_length = EVP_MD_size(ctx->md);
ctx->buf = malloc(ctx->key_length);
}
#if 0
ctx->engine = engine;
#endif
if (keylen > EVP_MD_block_size(ctx->md)) {
EVP_Digest(key, keylen, ctx->buf, NULL, ctx->md, engine);
key = ctx->buf;
keylen = EVP_MD_size(ctx->md);
}
if (ctx->opad) {
memset(ctx->opad, 0, ctx->key_length);
free(ctx->opad);
}
if (ctx->ipad) {
memset(ctx->ipad, 0, ctx->key_length);
free(ctx->ipad);
}
ctx->opad = malloc(EVP_MD_block_size(ctx->md));
ctx->ipad = malloc(EVP_MD_block_size(ctx->md));
memset(ctx->ipad, 0x36, EVP_MD_block_size(ctx->md));
memset(ctx->opad, 0x5c, EVP_MD_block_size(ctx->md));
for (i = 0, p = ctx->ipad; i < keylen; i++)
p[i] ^= ((const unsigned char *)key)[i];
for (i = 0, p = ctx->opad; i < keylen; i++)
p[i] ^= ((const unsigned char *)key)[i];
if (ctx->ctx == NULL)
ctx->ctx = EVP_MD_CTX_create();
EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine);
EVP_DigestUpdate(ctx->ctx, ctx->ipad, EVP_MD_block_size(ctx->md));
}
void
HMAC_Update(HMAC_CTX *ctx, const void *data, size_t len)
{
EVP_DigestUpdate(ctx->ctx, data, len);
}
void
HMAC_Final(HMAC_CTX *ctx, void *md, unsigned int *len)
{
EVP_DigestFinal_ex(ctx->ctx, ctx->buf, NULL);
EVP_DigestInit_ex(ctx->ctx, ctx->md, ctx->engine);
EVP_DigestUpdate(ctx->ctx, ctx->opad, EVP_MD_block_size(ctx->md));
EVP_DigestUpdate(ctx->ctx, ctx->buf, ctx->key_length);
EVP_DigestFinal_ex(ctx->ctx, md, len);
}
void *
HMAC(const EVP_MD *md,
const void *key, size_t key_size,
const void *data, size_t data_size,
void *hash, unsigned int *hash_len)
{
HMAC_CTX ctx;
HMAC_CTX_init(&ctx);
HMAC_Init_ex(&ctx, key, key_size, md, NULL);
HMAC_Update(&ctx, data, data_size);
HMAC_Final(&ctx, hash, hash_len);
HMAC_CTX_cleanup(&ctx);
return hash;
}
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