text: /*
   *  generic message digest layer demonstration program
   *
   *  Copyright (C) 2006-2011, Brainspark B.V.
   *
   *  This file is part of PolarSSL (http://www.polarssl.org)
   *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
   *
   *  All rights reserved.
   *
   *  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.,
   *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
   */
  
  #if !defined(POLARSSL_CONFIG_FILE)
  #include "polarssl/config.h"
  #else
  #include POLARSSL_CONFIG_FILE
  #endif
  
  #include <string.h>
  #include <stdio.h>
  
  #include "polarssl/md.h"
  
  #if !defined(POLARSSL_MD_C)
  int main( int argc, char *argv[] )
  {
      ((void) argc);
      ((void) argv);
  
      printf("POLARSSL_MD_C not defined.\n");
      return( 0 );
  }
  #else
  static int generic_wrapper( const md_info_t *md_info, char *filename, unsigned char *sum )
  {
      int ret = md_file( md_info, filename, sum );
  
      if( ret == 1 )
          fprintf( stderr, "failed to open: %s\n", filename );
  
      if( ret == 2 )
          fprintf( stderr, "failed to read: %s\n", filename );
  
      return( ret );
  }
  
  static int generic_print( const md_info_t *md_info, char *filename )
  {
      int i;
      unsigned char sum[POLARSSL_MD_MAX_SIZE];
  
      if( generic_wrapper( md_info, filename, sum ) != 0 )
          return( 1 );
  
      for( i = 0; i < md_info->size; i++ )
          printf( "%02x", sum[i] );
  
      printf( "  %s\n", filename );
      return( 0 );
  }
  
  static int generic_check( const md_info_t *md_info, char *filename )
  {
      int i;
      size_t n;
      FILE *f;
      int nb_err1, nb_err2;
      int nb_tot1, nb_tot2;
      unsigned char sum[POLARSSL_MD_MAX_SIZE];
      char buf[POLARSSL_MD_MAX_SIZE * 2 + 1], line[1024];
      char diff;
  
      if( ( f = fopen( filename, "rb" ) ) == NULL )
      {
          printf( "failed to open: %s\n", filename );
          return( 1 );
      }
  
      nb_err1 = nb_err2 = 0;
      nb_tot1 = nb_tot2 = 0;
  
      memset( line, 0, sizeof( line ) );
  
      n = sizeof( line );
  
      while( fgets( line, (int) n - 1, f ) != NULL )
      {
          n = strlen( line );
  
          if( n < (size_t) 2 * md_info->size + 4 )
          {
              printf("No '%s' hash found on line.\n", md_info->name);
              continue;
          }
  
          if( line[2 * md_info->size] != ' ' || line[2 * md_info->size + 1] != ' ' )
          {
              printf("No '%s' hash found on line.\n", md_info->name);
              continue;
          }
  
          if( line[n - 1] == '\n' ) { n--; line[n] = '\0'; }
          if( line[n - 1] == '\r' ) { n--; line[n] = '\0'; }
  
          nb_tot1++;
  
          if( generic_wrapper( md_info, line + 2 + 2 * md_info->size, sum ) != 0 )
          {
              nb_err1++;
              continue;
          }
  
          nb_tot2++;
  
          for( i = 0; i < md_info->size; i++ )
              sprintf( buf + i * 2, "%02x", sum[i] );
  
          /* Use constant-time buffer comparison */
          diff = 0;
          for( i = 0; i < 2 * md_info->size; i++ )
              diff |= line[i] ^ buf[i];
  
          if( diff != 0 )
          {
              nb_err2++;
              fprintf( stderr, "wrong checksum: %s\n", line + 66 );
          }
  
          n = sizeof( line );
      }
  
      if( nb_err1 != 0 )
      {
          printf( "WARNING: %d (out of %d) input files could "
                  "not be read\n", nb_err1, nb_tot1 );
      }
  
      if( nb_err2 != 0 )
      {
          printf( "WARNING: %d (out of %d) computed checksums did "
                  "not match\n", nb_err2, nb_tot2 );
      }
  
      fclose( f );
  
      return( nb_err1 != 0 || nb_err2 != 0 );
  }
  
  int main( int argc, char *argv[] )
  {
      int ret, i;
      const md_info_t *md_info;
      md_context_t md_ctx;
  
      md_init( &md_ctx );
  
      if( argc == 1 )
      {
          const int *list;
  
          printf( "print mode:  generic_sum <md> <file> <file> ...\n" );
          printf( "check mode:  generic_sum <md> -c <checksum file>\n" );
  
          printf( "\nAvailable message digests:\n" );
          list = md_list();
          while( *list )
          {
              md_info = md_info_from_type( *list );
              printf( "  %s\n", md_info->name );
              list++;
          }
  
  #if defined(_WIN32)
          printf( "\n  Press Enter to exit this program.\n" );
          fflush( stdout ); getchar();
  #endif
  
          return( 1 );
      }
  
      /*
       * Read the MD from the command line
       */
      md_info = md_info_from_string( argv[1] );
      if( md_info == NULL )
      {
          fprintf( stderr, "Message Digest '%s' not found\n", argv[1] );
          return( 1 );
      }
      if( md_init_ctx( &md_ctx, md_info) )
      {
          fprintf( stderr, "Failed to initialize context.\n" );
          return( 1 );
      }
  
      ret = 0;
      if( argc == 4 && strcmp( "-c", argv[2] ) == 0 )
      {
          ret |= generic_check( md_info, argv[3] );
          goto exit;
      }
  
      for( i = 2; i < argc; i++ )
          ret |= generic_print( md_info, argv[i] );
  
  exit:
      md_free( &md_ctx );
  
      return( ret );
  }
  #endif /* POLARSSL_MD_C */
  