/**
   * \file sha1.h
   * based from http://xyssl.org/code/source/sha1/
   *  FIPS-180-1 compliant SHA-1 implementation
   *
   *  Copyright (C) 2003-2006  Christophe Devine
   *
   *  This library is free software; you can redistribute it and/or
   *  modify it under the terms of the GNU Lesser General Public
   *  License, version 2.1 as published by the Free Software Foundation.
   *
   *  This library 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
   *  Lesser General Public License for more details.
   *
   *  You should have received a copy of the GNU Lesser General Public
   *  License along with this library; if not, write to the Free Software
   *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,

   *  MA	02110-1301  USA

   */
  /*
   *  The SHA-1 standard was published by NIST in 1993.
   *
   *  http://www.itl.nist.gov/fipspubs/fip180-1.htm
   */
  #ifndef _SHA1_H
  #define _SHA1_H
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #define SHA1_SUM_POS	-0x20
  #define SHA1_SUM_LEN	20
  
  /**

   * \brief	   SHA-1 context structure

   */
  typedef struct
  {

      unsigned long total[2];	/*!< number of bytes processed	*/
      unsigned long state[5];	/*!< intermediate digest state	*/
      unsigned char buffer[64];	/*!< data block being processed */

  }
  sha1_context;
  
  /**

   * \brief	   SHA-1 context setup

   *

   * \param ctx	   SHA-1 context to be initialized

   */
  void sha1_starts( sha1_context *ctx );
  
  /**

   * \brief	   SHA-1 process buffer

   *

   * \param ctx	   SHA-1 context

   * \param input    buffer holding the  data

   * \param ilen	   length of the input data

   */

  void sha1_update(sha1_context *ctx, const unsigned char *input,
  		 unsigned int ilen);

  
  /**

   * \brief	   SHA-1 final digest

   *

   * \param ctx	   SHA-1 context

   * \param output   SHA-1 checksum result
   */
  void sha1_finish( sha1_context *ctx, unsigned char output[20] );
  
  /**

   * \brief	   Output = SHA-1( input buffer )

   *
   * \param input    buffer holding the  data

   * \param ilen	   length of the input data

   * \param output   SHA-1 checksum result
   */

  void sha1_csum(const unsigned char *input, unsigned int ilen,
  		unsigned char *output);

  
  /**

   * \brief	   Output = SHA-1( input buffer ), with watchdog triggering
   *
   * \param input    buffer holding the  data
   * \param ilen	   length of the input data
   * \param output   SHA-1 checksum result
   * \param chunk_sz watchdog triggering period (in bytes of input processed)
   */

  void sha1_csum_wd(const unsigned char *input, unsigned int ilen,
  		unsigned char *output, unsigned int chunk_sz);

  
  /**

   * \brief	   Output = HMAC-SHA-1( input buffer, hmac key )

   *

   * \param key	   HMAC secret key

   * \param keylen   length of the HMAC key
   * \param input    buffer holding the  data

   * \param ilen	   length of the input data

   * \param output   HMAC-SHA-1 result
   */

  void sha1_hmac(const unsigned char *key, int keylen,
  		const unsigned char *input, unsigned int ilen,
  		unsigned char *output);

  
  /**

   * \brief	   Checkup routine

   *

   * \return	   0 if successful, or 1 if the test failed

   */
  int sha1_self_test( void );
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* sha1.h */