text: /*
   *  RFC 1521 base64 encoding/decoding
   *
   *  Copyright (C) 2006-2010, 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.
   */
  
  #include "polarssl/config.h"
  
  #if defined(POLARSSL_BASE64_C)
  
  #include "polarssl/base64.h"
  
  #ifdef _MSC_VER
  #include <basetsd.h>
  typedef UINT32 uint32_t;
  #else
  #include <inttypes.h>
  #endif
  
  static const unsigned char base64_enc_map[64] =
  {
      'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J',
      'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T',
      'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',
      'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
      'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x',
      'y', 'z', '0', '1', '2', '3', '4', '5', '6', '7',
      '8', '9', '+', '/'
  };
  
  static const unsigned char base64_dec_map[128] =
  {
      127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
      127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
      127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
      127, 127, 127, 127, 127, 127, 127, 127, 127, 127,
      127, 127, 127,  62, 127, 127, 127,  63,  52,  53,
       54,  55,  56,  57,  58,  59,  60,  61, 127, 127,
      127,  64, 127, 127, 127,   0,   1,   2,   3,   4,
        5,   6,   7,   8,   9,  10,  11,  12,  13,  14,
       15,  16,  17,  18,  19,  20,  21,  22,  23,  24,
       25, 127, 127, 127, 127, 127, 127,  26,  27,  28,
       29,  30,  31,  32,  33,  34,  35,  36,  37,  38,
       39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
       49,  50,  51, 127, 127, 127, 127, 127
  };
  
  /*
   * Encode a buffer into base64 format
   */
  int base64_encode( unsigned char *dst, size_t *dlen,
                     const unsigned char *src, size_t slen )
  {
      size_t i, n;
      int C1, C2, C3;
      unsigned char *p;
  
      if( slen == 0 )
          return( 0 );
  
      n = (slen << 3) / 6;
  
      switch( (slen << 3) - (n * 6) )
      {
          case  2: n += 3; break;
          case  4: n += 2; break;
          default: break;
      }
  
      if( *dlen < n + 1 )
      {
          *dlen = n + 1;
          return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
      }
  
      n = (slen / 3) * 3;
  
      for( i = 0, p = dst; i < n; i += 3 )
      {
          C1 = *src++;
          C2 = *src++;
          C3 = *src++;
  
          *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
          *p++ = base64_enc_map[(((C1 &  3) << 4) + (C2 >> 4)) & 0x3F];
          *p++ = base64_enc_map[(((C2 & 15) << 2) + (C3 >> 6)) & 0x3F];
          *p++ = base64_enc_map[C3 & 0x3F];
      }
  
      if( i < slen )
      {
          C1 = *src++;
          C2 = ((i + 1) < slen) ? *src++ : 0;
  
          *p++ = base64_enc_map[(C1 >> 2) & 0x3F];
          *p++ = base64_enc_map[(((C1 & 3) << 4) + (C2 >> 4)) & 0x3F];
  
          if( (i + 1) < slen )
               *p++ = base64_enc_map[((C2 & 15) << 2) & 0x3F];
          else *p++ = '=';
  
          *p++ = '=';
      }
  
      *dlen = p - dst;
      *p = 0;
  
      return( 0 );
  }
  
  /*
   * Decode a base64-formatted buffer
   */
  int base64_decode( unsigned char *dst, size_t *dlen,
                     const unsigned char *src, size_t slen )
  {
      size_t i, n;
      uint32_t j, x;
      unsigned char *p;
  
      for( i = j = n = 0; i < slen; i++ )
      {
          if( ( slen - i ) >= 2 &&
              src[i] == '\r' && src[i + 1] == '\n' )
              continue;
  
          if( src[i] == '\n' )
              continue;
  
          if( src[i] == '=' && ++j > 2 )
              return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  
          if( src[i] > 127 || base64_dec_map[src[i]] == 127 )
              return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  
          if( base64_dec_map[src[i]] < 64 && j != 0 )
              return( POLARSSL_ERR_BASE64_INVALID_CHARACTER );
  
          n++;
      }
  
      if( n == 0 )
          return( 0 );
  
      n = ((n * 6) + 7) >> 3;
  
      if( *dlen < n )
      {
          *dlen = n;
          return( POLARSSL_ERR_BASE64_BUFFER_TOO_SMALL );
      }
  
     for( j = 3, n = x = 0, p = dst; i > 0; i--, src++ )
     {
          if( *src == '\r' || *src == '\n' )
              continue;
  
          j -= ( base64_dec_map[*src] == 64 );
          x  = (x << 6) | ( base64_dec_map[*src] & 0x3F );
  
          if( ++n == 4 )
          {
              n = 0;
              if( j > 0 ) *p++ = (unsigned char)( x >> 16 );
              if( j > 1 ) *p++ = (unsigned char)( x >>  8 );
              if( j > 2 ) *p++ = (unsigned char)( x       );
          }
      }
  
      *dlen = p - dst;
  
      return( 0 );
  }
  
  #if defined(POLARSSL_SELF_TEST)
  
  #include <string.h>
  #include <stdio.h>
  
  static const unsigned char base64_test_dec[64] =
  {
      0x24, 0x48, 0x6E, 0x56, 0x87, 0x62, 0x5A, 0xBD,
      0xBF, 0x17, 0xD9, 0xA2, 0xC4, 0x17, 0x1A, 0x01,
      0x94, 0xED, 0x8F, 0x1E, 0x11, 0xB3, 0xD7, 0x09,
      0x0C, 0xB6, 0xE9, 0x10, 0x6F, 0x22, 0xEE, 0x13,
      0xCA, 0xB3, 0x07, 0x05, 0x76, 0xC9, 0xFA, 0x31,
      0x6C, 0x08, 0x34, 0xFF, 0x8D, 0xC2, 0x6C, 0x38,
      0x00, 0x43, 0xE9, 0x54, 0x97, 0xAF, 0x50, 0x4B,
      0xD1, 0x41, 0xBA, 0x95, 0x31, 0x5A, 0x0B, 0x97
  };
  
  static const unsigned char base64_test_enc[] =
      "JEhuVodiWr2/F9mixBcaAZTtjx4Rs9cJDLbpEG8i7hPK"
      "swcFdsn6MWwINP+Nwmw4AEPpVJevUEvRQbqVMVoLlw==";
  
  /*
   * Checkup routine
   */
  int base64_self_test( int verbose )
  {
      size_t len;
      const unsigned char *src;
      unsigned char buffer[128];
  
      if( verbose != 0 )
          printf( "  Base64 encoding test: " );
  
      len = sizeof( buffer );
      src = base64_test_dec;
  
      if( base64_encode( buffer, &len, src, 64 ) != 0 ||
           memcmp( base64_test_enc, buffer, 88 ) != 0 )
      {
          if( verbose != 0 )
              printf( "failed\n" );
  
          return( 1 );
      }
  
      if( verbose != 0 )
          printf( "passed\n  Base64 decoding test: " );
  
      len = sizeof( buffer );
      src = base64_test_enc;
  
      if( base64_decode( buffer, &len, src, 88 ) != 0 ||
           memcmp( base64_test_dec, buffer, 64 ) != 0 )
      {
          if( verbose != 0 )
              printf( "failed\n" );
  
          return( 1 );
      }
  
      if( verbose != 0 )
          printf( "passed\n\n" );
  
      return( 0 );
  }
  
  #endif
  
  #endif
  