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cryb-to/lib/mac/cryb_hmac_sha512.c

103 lines
3.1 KiB
C

/*-
* Copyright (c) 2012 The University of Oslo
* Copyright (c) 2012-2016 Dag-Erling Smørgrav
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior written
* permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 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.
*/
#include "cryb/impl.h"
#if HAVE_SYS_ENDIAN_H
#include <sys/endian.h>
#endif
#if HAVE_ENDIAN_H
#define _BSD_SOURCE
#include <endian.h>
#endif
#include <stdint.h>
#include <string.h>
#include <cryb/hmac_sha512.h>
void
hmac_sha512_init(hmac_sha512_ctx *ctx, const void *key, size_t keylen)
{
uint8_t keybuf[SHA512_BLOCK_LEN], pad[SHA512_BLOCK_LEN];
/* prepare key */
memset(keybuf, 0, sizeof keybuf);
if (keylen > sizeof keybuf)
sha512_complete(key, keylen, keybuf);
else
memcpy(keybuf, key, keylen);
/* input pad */
for (unsigned int i = 0; i < sizeof pad; ++i)
pad[i] = 0x36 ^ keybuf[i];
sha512_init(&ctx->ictx);
sha512_update(&ctx->ictx, pad, sizeof pad);
/* output pad */
for (unsigned int i = 0; i < sizeof pad; ++i)
pad[i] = 0x5c ^ keybuf[i];
sha512_init(&ctx->octx);
sha512_update(&ctx->octx, pad, sizeof pad);
/* hide the evidence */
memset(keybuf, 0, sizeof keybuf);
memset(pad, 0, sizeof pad);
}
void
hmac_sha512_update(hmac_sha512_ctx *ctx, const void *buf, size_t len)
{
sha512_update(&ctx->ictx, buf, len);
}
void
hmac_sha512_final(hmac_sha512_ctx *ctx, uint8_t *mac)
{
uint8_t digest[SHA512_DIGEST_LEN];
sha512_final(&ctx->ictx, digest);
sha512_update(&ctx->octx, digest, sizeof digest);
sha512_final(&ctx->octx, mac);
memset(ctx, 0, sizeof *ctx);
}
void
hmac_sha512_complete(const void *key, size_t keylen,
const void *buf, size_t len, uint8_t *mac)
{
hmac_sha512_ctx ctx;
hmac_sha512_init(&ctx, key, keylen);
hmac_sha512_update(&ctx, buf, len);
hmac_sha512_final(&ctx, mac);
}