src/Base64.cpp

   1 #include "Base64.h"
   2
   3
   4
   5
   6 EXPORT_C HBufC8* TBase64::Base64_EncodeL( const TDesC8& aSrcString )  {
   7
   8         const TInt base64Chars[]= {'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',
   9         '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',
  10         '0','1','2','3','4','5','6','7','8','9','+','/' };
  11
  12
  13         TInt encodedLength = 0;
  14
  15         if ( aSrcString.Length() % 3 == 0 )
  16                 encodedLength = (aSrcString.Length() / 3) * 4;
  17         else
  18                 encodedLength = (aSrcString.Length() / 3) * 4 + 4;
  19
  20         HBufC8* encoded = HBufC8::NewL( encodedLength );
  21
  22         TBuf8<3> char_array_3;
  23         char_array_3.Zero();
  24         char_array_3.SetLength( 3 );
  25
  26         TBuf8<4> char_array_4;
  27         char_array_4.Zero();
  28         char_array_4.SetLength( 4 );
  29
  30         TInt index = aSrcString.Length();
  31         TInt i = 0;
  32         TInt j = 0;
  33
  34         while ( index-- ) {
  35                 char_array_3[i++] = aSrcString[j++];
  36
  37                 if (i == 3) {
  38                   char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
  39                   char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
  40                   char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
  41                   char_array_4[3] = char_array_3[2] & 0x3f;
  42
  43                   for(i = 0; (i <4) ; i++)
  44                         encoded->Des().Append( base64Chars[char_array_4[i]] );
  45                   i = 0;
  46                 }
  47         }
  48
  49   if (i)
  50   {
  51     for(j = i; j < 3; j++)
  52       char_array_3[j] = '\0';
  53
  54     char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
  55     char_array_4[1] = ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
  56     char_array_4[2] = ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
  57     char_array_4[3] = char_array_3[2] & 0x3f;
  58
  59     for (j = 0; (j < i + 1); j++)
  60       encoded->Des().Append( base64Chars[char_array_4[j]] );
  61
  62     while((i++ < 3))
  63       encoded->Des().Append( '=' );
  64
  65   }
  66
  67         return encoded;
  68 }
  69
  70
  71 EXPORT_C HBufC8* TBase64::Base64_DecodeL( const TDesC8& aSrcString )  {
  72
  73         const TInt base64Chars[]= {'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',
  74         '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',
  75         '0','1','2','3','4','5','6','7','8','9','+','/' };
  76
  77         TInt decodedLength = aSrcString.Length() / 4 * 3 + 3;
  78         HBufC8* decoded = HBufC8::NewL( decodedLength );
  79
  80         TInt index = aSrcString.Length();
  81         TInt i = 0;
  82         TInt j = 0;
  83         TInt in_ = 0;
  84
  85         TBuf8<3> char_array_3;
  86         char_array_3.Zero();
  87         char_array_3.SetLength( 3 );
  88
  89         TBuf8<4> char_array_4;
  90         char_array_4.Zero();
  91         char_array_4.SetLength( 4 );
  92
  93         while (index-- && ( aSrcString[in_] != '=') /*&& is_base64(encoded_string[in_])*/ ) {
  94
  95     TInt inchar = aSrcString[in_++];
  96     // Include only '+', '/0123456789', 'A....Z' and 'a....z'
  97     if( !(inchar == 43 || (inchar >= 47 && inchar <= 57) || (inchar >= 65 && inchar <= 90) ||
  98       (inchar >= 97 && inchar <= 122)) )
  99       continue;
 100
 101                 char_array_4[i++] = TChar(inchar);
 102
 103                 if (i == 4)  {
 104                         for (i = 0; i < 4; i++)
 105                                 for( TInt charIndex = 0; charIndex < 64 ; charIndex++ )  {
 106                                         if( base64Chars[charIndex] == char_array_4[i] )  {
 107                                                 char_array_4[i] = charIndex;
 108                                                 break;
 109                                         }
 110                                 }
 111
 112                         char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
 113                         char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
 114                         char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
 115
 116                         for (i = 0; (i < 3); i++)
 117                                 decoded->Des().Append( char_array_3[i] );
 118
 119                         i = 0;
 120                 }
 121         }
 122
 123         if (i) {
 124                 for (j = i; j < 4; j++)
 125                   char_array_4[j] = 0;
 126
 127                 for (j = 0; j <4; j++)
 128                         for( TInt charIndex = 0; charIndex<64 ; charIndex++ )  {
 129                                 if( base64Chars[charIndex] == char_array_4[j] )  {
 130                                         char_array_4[j] = charIndex;
 131                                         break;
 132                                 }
 133                         }
 134
 135                 char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
 136                 char_array_3[1] = ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
 137                 char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
 138
 139                 for (j = 0; (j < i - 1); j++) decoded->Des().Append( char_array_3[j] );
 140         }
 141
 142         return decoded;
 143
 144 }