hmac.h

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/* dtls -- a very basic DTLS implementation
 *
 * Copyright (C) 2011--2012 Olaf Bergmann <bergmann@tzi.org>
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use, copy,
 * modify, merge, publish, distribute, sublicense, and/or sell copies
 * of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#ifndef _DTLS_HMAC_H_
#define _DTLS_HMAC_H_

#include <sys/types.h>

#include "global.h"

#ifdef WITH_SHA256

#include "sha2/sha2.h"

typedef SHA256_CTX dtls_hash_ctx;
typedef dtls_hash_ctx *dtls_hash_t;
#define DTLS_HASH_CTX_SIZE sizeof(SHA256_CTX)

static inline void
dtls_hash_init(dtls_hash_t ctx) {
  SHA256_Init((SHA256_CTX *)ctx);
}

static inline void 
dtls_hash_update(dtls_hash_t ctx, const unsigned char *input, size_t len) {
  SHA256_Update((SHA256_CTX *)ctx, input, len);
}

static inline size_t
dtls_hash_finalize(unsigned char *buf, dtls_hash_t ctx) {
  SHA256_Final(buf, (SHA256_CTX *)ctx);
  return SHA256_DIGEST_LENGTH;
}
#endif /* WITH_SHA256 */

#ifndef WITH_CONTIKI
static inline void dtls_hmac_storage_init()
{ }
#else
void dtls_hmac_storage_init();
#endif

#define DTLS_HMAC_BLOCKSIZE   64    
#define DTLS_HMAC_DIGEST_SIZE 32    
#define DTLS_HMAC_MAX         64    
typedef enum { 
  HASH_NONE=0, HASH_MD5=1, HASH_SHA1=2, HASH_SHA224=3,
  HASH_SHA256=4, HASH_SHA384=5, HASH_SHA512=6
} dtls_hashfunc_t;

typedef struct {
  unsigned char pad[DTLS_HMAC_BLOCKSIZE]; 
  dtls_hash_ctx data;                 
} dtls_hmac_context_t;

void dtls_hmac_init(dtls_hmac_context_t *ctx, const unsigned char *key, size_t klen);

dtls_hmac_context_t *dtls_hmac_new(const unsigned char *key, size_t klen);

void dtls_hmac_free(dtls_hmac_context_t *ctx);

void dtls_hmac_update(dtls_hmac_context_t *ctx,
              const unsigned char *input, size_t ilen);

int dtls_hmac_finalize(dtls_hmac_context_t *ctx, unsigned char *result);

#endif /* _DTLS_HMAC_H_ */