hmac.c
/* crypto/hmac/hmac.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* 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 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. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``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 AUTHOR 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.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "cryptlib.h"
#include <openssl/hmac.h>
#ifndef OPENSSL_FIPS
void HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len,
const EVP_MD *md, ENGINE *impl)
{
int i, j, reset = 0;
unsigned char pad[HMAC_MAX_MD_CBLOCK];
if (md != NULL) {
reset = 1;
ctx->md = md;
} else
md = ctx->md;
if (key != NULL) {
reset = 1;
j = EVP_MD_block_size(md);
OPENSSL_assert(j <= (int)sizeof(ctx->key));
if (j < len) {
EVP_DigestInit_ex(&ctx->md_ctx, md, impl);
EVP_DigestUpdate(&ctx->md_ctx, key, len);
EVP_DigestFinal_ex(&(ctx->md_ctx), ctx->key, &ctx->key_length);
} else {
OPENSSL_assert(len >= 0 && len <= (int)sizeof(ctx->key));
memcpy(ctx->key, key, len);
ctx->key_length = len;
}
if (ctx->key_length != HMAC_MAX_MD_CBLOCK)
memset(&ctx->key[ctx->key_length], 0,
HMAC_MAX_MD_CBLOCK - ctx->key_length);
}
if (reset) {
for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
pad[i] = 0x36 ^ ctx->key[i];
EVP_DigestInit_ex(&ctx->i_ctx, md, impl);
EVP_DigestUpdate(&ctx->i_ctx, pad, EVP_MD_block_size(md));
for (i = 0; i < HMAC_MAX_MD_CBLOCK; i++)
pad[i] = 0x5c ^ ctx->key[i];
EVP_DigestInit_ex(&ctx->o_ctx, md, impl);
EVP_DigestUpdate(&ctx->o_ctx, pad, EVP_MD_block_size(md));
}
EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->i_ctx);
}
void HMAC_Init(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md)
{
if (key && md)
HMAC_CTX_init(ctx);
HMAC_Init_ex(ctx, key, len, md, NULL);
}
void HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len)
{
EVP_DigestUpdate(&ctx->md_ctx, data, len);
}
void HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len)
{
unsigned int i;
unsigned char buf[EVP_MAX_MD_SIZE];
EVP_DigestFinal_ex(&ctx->md_ctx, buf, &i);
EVP_MD_CTX_copy_ex(&ctx->md_ctx, &ctx->o_ctx);
EVP_DigestUpdate(&ctx->md_ctx, buf, i);
EVP_DigestFinal_ex(&ctx->md_ctx, md, len);
}
void HMAC_CTX_init(HMAC_CTX *ctx)
{
EVP_MD_CTX_init(&ctx->i_ctx);
EVP_MD_CTX_init(&ctx->o_ctx);
EVP_MD_CTX_init(&ctx->md_ctx);
}
void HMAC_CTX_cleanup(HMAC_CTX *ctx)
{
EVP_MD_CTX_cleanup(&ctx->i_ctx);
EVP_MD_CTX_cleanup(&ctx->o_ctx);
EVP_MD_CTX_cleanup(&ctx->md_ctx);
memset(ctx, 0, sizeof *ctx);
}
unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
const unsigned char *d, size_t n, unsigned char *md,
unsigned int *md_len)
{
HMAC_CTX c;
static unsigned char m[EVP_MAX_MD_SIZE];
if (md == NULL)
md = m;
HMAC_CTX_init(&c);
HMAC_Init(&c, key, key_len, evp_md);
HMAC_Update(&c, d, n);
HMAC_Final(&c, md, md_len);
HMAC_CTX_cleanup(&c);
return (md);
}
void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags)
{
EVP_MD_CTX_set_flags(&ctx->i_ctx, flags);
EVP_MD_CTX_set_flags(&ctx->o_ctx, flags);
EVP_MD_CTX_set_flags(&ctx->md_ctx, flags);
}
#endif
