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/*
* Copyright (C) 2015 Broadcom Corporation
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation version 2.
*
* This program is distributed "as is" WITHOUT ANY WARRANTY of any
* kind, whether express or implied; without even the implied warranty
* of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include "secimage.h"
#include <openssl/hmac.h>
/*----------------------------------------------------------------------
* Name : HmacSha256Hash
* Purpose :
* Input : none
* Output : none
*---------------------------------------------------------------------*/
int HmacSha256Hash(uint8_t *data, uint32_t len, uint8_t *hash, uint8_t *key)
{
HMAC_CTX hctx;
HMAC_CTX_init(&hctx);
HMAC_Init_ex(&hctx, key, 32, EVP_sha256(), NULL);
/*
* FIXME: why we need this? NULL means to use whatever there is?
* if removed, result is different
*/
HMAC_Init_ex(&hctx, NULL, 0, NULL, NULL);
HMAC_Update(&hctx, data, len);
HMAC_Final(&hctx, hash, NULL);
HMAC_CTX_cleanup(&hctx);
return 0;
}
/*----------------------------------------------------------------------
* Name : AppendHMACSignature
* Purpose : Appends HMAC signature at the end of the data
*---------------------------------------------------------------------*/
int AppendHMACSignature(uint8_t *data, uint32_t length, char *filename,
uint32_t offset)
{
uint8_t hmackey[32];
uint32_t len;
uint32_t status;
uint8_t *digest = data + length;
len = ReadBinaryFile(filename, hmackey, 32);
if (len != 32) {
printf("Error reading hmac key file\n");
return 0;
}
status = HmacSha256Hash(&data[offset], length - offset, digest,
hmackey);
if (status) {
printf("HMAC-SHA256 hash error\n");
return 0;
}
return 32;
}
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