text: /* $Id: hmac_md5.h 3553 2011-05-05 06:14:19Z nanang $ */
  /* 
   * Copyright (C) 2008-2011 Teluu Inc. (http://www.teluu.com)
   * Copyright (C) 2003-2008 Benny Prijono <benny@prijono.org>
   *
   * 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; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, write to the Free Software
   * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA 
   */
  #ifndef __PJLIB_UTIL_HMAC_MD5_H__
  #define __PJLIB_UTIL_HMAC_MD5_H__
  
  /**
   * @file hmac_md5.h
   * @brief HMAC MD5 Message Authentication
   */
  
  /**
   * @defgroup PJLIB_UTIL_ENCRYPTION Encryption Algorithms
   */
  
  #include <pj/types.h>
  #include <pjlib-util/md5.h>
  
  PJ_BEGIN_DECL
  
  /**
   * @defgroup PJLIB_UTIL_HMAC_MD5 HMAC MD5 Message Authentication
   * @ingroup PJLIB_UTIL_ENCRYPTION
   * @{
   *
   * This module contains the implementation of HMAC: Keyed-Hashing 
   * for Message Authentication, as described in RFC 2104
   */
  
  /**
   * The HMAC-MD5 context used in the incremental HMAC calculation.
   */
  typedef struct pj_hmac_md5_context
  {
      pj_md5_context  context;	/**< MD5 context	    */
      pj_uint8_t	    k_opad[64];	/**< opad xor-ed with key   */
  } pj_hmac_md5_context;
  
  
  /**
   * Calculate HMAC MD5 digest for the specified input and key.
   *
   * @param input		Pointer to the input stream.
   * @param input_len	Length of input stream in bytes.
   * @param key		Pointer to the authentication key.
   * @param key_len	Length of the authentication key.
   * @param digest	Buffer to be filled with HMAC MD5 digest.
   */
  PJ_DECL(void) pj_hmac_md5(const pj_uint8_t *input, unsigned input_len, 
  			  const pj_uint8_t *key, unsigned key_len, 
  			  pj_uint8_t digest[16]);
  
  
  /**
   * Initiate HMAC-MD5 context for incremental hashing.
   *
   * @param hctx		HMAC-MD5 context.
   * @param key		Pointer to the authentication key.
   * @param key_len	Length of the authentication key.
   */
  PJ_DECL(void) pj_hmac_md5_init(pj_hmac_md5_context *hctx, 
  			       const pj_uint8_t *key, unsigned key_len);
  
  /**
   * Append string to the message.
   *
   * @param hctx		HMAC-MD5 context.
   * @param input		Pointer to the input stream.
   * @param input_len	Length of input stream in bytes.
   */
  PJ_DECL(void) pj_hmac_md5_update(pj_hmac_md5_context *hctx,
  				 const pj_uint8_t *input, 
  				 unsigned input_len);
  
  /**
   * Finish the message and return the digest. 
   *
   * @param hctx		HMAC-MD5 context.
   * @param digest	Buffer to be filled with HMAC MD5 digest.
   */
  PJ_DECL(void) pj_hmac_md5_final(pj_hmac_md5_context *hctx,
  				pj_uint8_t digest[16]);
  
  /**
   * @}
   */
  
  PJ_END_DECL
  
  
  #endif	/* __PJLIB_UTIL_HMAC_MD5_H__ */
  
  
  