sapphire/src/common/Crypt/base64.cpp

/*
   base64.cpp and base64.h

   Copyright (C) 2004-2008 Ren<65> Nyffenegger

   This source code is provided 'as-is', without any express or implied
   warranty. In no event will the author be held liable for any damages
   arising from the use of this software.

   Permission is granted to anyone to use this software for any purpose,
   including commercial applications, and to alter it and redistribute it
   freely, subject to the following restrictions:

   1. The origin of this source code must not be misrepresented; you must not
      claim that you wrote the original source code. If you use this source code
      in a product, an acknowledgment in the product documentation would be
      appreciated but is not required.

   2. Altered source versions must be plainly marked as such, and must not be
      misrepresented as being the original source code.

   3. This notice may not be removed or altered from any source distribution.

   Ren<65> Nyffenegger rene.nyffenegger@adp-gmbh.ch

*/

#include "base64.h"
#include <iostream>

static const std::string base64_chars =
  "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
  "abcdefghijklmnopqrstuvwxyz"
  "0123456789+/";


static inline bool is_base64( uint8_t c )
{
  return ( isalnum( c ) || ( c == '+' ) || ( c == '/' ) );
}

std::string Core::Util::base64_encode( uint8_t const* bytes_to_encode, uint32_t in_len )
{
  std::string ret;
  int32_t i = 0;
  int32_t j = 0;
  uint8_t char_array_3[3];
  uint8_t char_array_4[4];

  while( in_len-- )
  {
    char_array_3[ i++ ] = *( bytes_to_encode++ );
    if( i == 3 )
    {
      char_array_4[ 0 ] = ( char_array_3[ 0 ] & 0xfc ) >> 2;
      char_array_4[ 1 ] = ( ( char_array_3[ 0 ] & 0x03 ) << 4 ) + ( ( char_array_3[ 1 ] & 0xf0 ) >> 4 );
      char_array_4[ 2 ] = ( ( char_array_3[ 1 ] & 0x0f ) << 2 ) + ( ( char_array_3[ 2 ] & 0xc0 ) >> 6 );
      char_array_4[ 3 ] = char_array_3[ 2 ] & 0x3f;

      for( i = 0; ( i < 4 ); i++ )
        ret += base64_chars[ char_array_4[ i ] ];
      i = 0;
    }
  }

  if( i )
  {
    for( j = i; j < 3; j++ )
      char_array_3[ j ] = '\0';

    char_array_4[ 0 ] = ( char_array_3[ 0 ] & 0xfc ) >> 2;
    char_array_4[ 1 ] = ( ( char_array_3[ 0 ] & 0x03 ) << 4 ) + ( ( char_array_3[ 1 ] & 0xf0 ) >> 4 );
    char_array_4[ 2 ] = ( ( char_array_3[ 1 ] & 0x0f ) << 2 ) + ( ( char_array_3[ 2 ] & 0xc0 ) >> 6 );
    char_array_4[ 3 ] = char_array_3[ 2 ] & 0x3f;

    for( j = 0; ( j < i + 1 ); j++ )
      ret += base64_chars[ char_array_4[ j ] ];

    while( ( i++ < 3 ) )
      ret += '=';

  }

  return ret;

}

std::string Core::Util::base64_decode( std::string const& encoded_string )
{
  int32_t in_len = encoded_string.size();
  int32_t i = 0;
  int32_t j = 0;
  int32_t in_ = 0;
  uint8_t char_array_4[4], char_array_3[3];
  std::string ret;

  while( in_len-- && ( encoded_string[ in_ ] != '=' ) && is_base64( encoded_string[ in_ ] ) )
  {
    char_array_4[ i++ ] = encoded_string[ in_ ];
    in_++;
    if( i == 4 )
    {
      for( i = 0; i < 4; i++ )
        char_array_4[ i ] = static_cast< uint8_t >( base64_chars.find( char_array_4[ i ] ) );

      char_array_3[ 0 ] = ( char_array_4[ 0 ] << 2 ) + ( ( char_array_4[ 1 ] & 0x30 ) >> 4 );
      char_array_3[ 1 ] = ( ( char_array_4[ 1 ] & 0xf ) << 4 ) + ( ( char_array_4[ 2 ] & 0x3c ) >> 2 );
      char_array_3[ 2 ] = ( ( char_array_4[ 2 ] & 0x3 ) << 6 ) + char_array_4[ 3 ];

      for( i = 0; ( i < 3 ); i++ )
        ret += char_array_3[ i ];
      i = 0;
    }
  }

  if( i )
  {
    for( j = i; j < 4; j++ )
      char_array_4[ j ] = 0;

    for( j = 0; j < 4; j++ )
      char_array_4[ j ] = static_cast< uint8_t >( base64_chars.find( char_array_4[ j ] ) );

    char_array_3[ 0 ] = ( char_array_4[ 0 ] << 2 ) + ( ( char_array_4[ 1 ] & 0x30 ) >> 4 );
    char_array_3[ 1 ] = ( ( char_array_4[ 1 ] & 0xf ) << 4 ) + ( ( char_array_4[ 2 ] & 0x3c ) >> 2 );
    char_array_3[ 2 ] = ( ( char_array_4[ 2 ] & 0x3 ) << 6 ) + char_array_4[ 3 ];

    for( j = 0; ( j < i - 1 ); j++ )
      ret += char_array_3[ j ];
  }

  return ret;
}