/* $OpenBSD: hmac.h,v 1.11 2014/06/12 15:49:29 deraadt Exp $ */
/* 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.]
 */
#ifndef HEADER_HMAC_H
#define HEADER_HMAC_H

#include <openssl/opensslconf.h>

#ifdef OPENSSL_NO_HMAC
#error HMAC is disabled.
#endif

#include <openssl/evp.h>

#define HMAC_MAX_MD_CBLOCK	128	/* largest known is SHA512 */

#ifdef  __cplusplus
extern "C" {
#endif

typedef struct hmac_ctx_st {
	const EVP_MD *md;
	EVP_MD_CTX md_ctx;
	EVP_MD_CTX i_ctx;
	EVP_MD_CTX o_ctx;
	unsigned int key_length;
	unsigned char key[HMAC_MAX_MD_CBLOCK];
} HMAC_CTX;

#define HMAC_size(e)	(EVP_MD_size((e)->md))


void HMAC_CTX_init(HMAC_CTX *ctx);
void HMAC_CTX_cleanup(HMAC_CTX *ctx);

#define HMAC_cleanup(ctx) HMAC_CTX_cleanup(ctx) /* deprecated */

int HMAC_Init(HMAC_CTX *ctx, const void *key, int len,
    const EVP_MD *md); /* deprecated */
int HMAC_Init_ex(HMAC_CTX *ctx, const void *key, int len, const EVP_MD *md,
    ENGINE *impl);
int HMAC_Update(HMAC_CTX *ctx, const unsigned char *data, size_t len);
int HMAC_Final(HMAC_CTX *ctx, unsigned char *md, unsigned int *len);
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);
int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx);

void HMAC_CTX_set_flags(HMAC_CTX *ctx, unsigned long flags);

#ifdef  __cplusplus
}
#endif

#endif
