src/base64.cpp

   1 #include "../include/base64.h"\r
   2 \r
   3 #ifdef XMEM\r
   4         #include <xmem.h>\r
   5 #endif\r
   6 \r
   7 namespace Base64\r
   8 {\r
   9 \r
  10 static const std::string base64chars="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";\r
  11 \r
  12 const bool Encode(const std::vector<unsigned char> &data, std::string &encoded)\r
  13 {\r
  14         std::vector<unsigned char>::size_type currentdatapos=0;\r
  15 \r
  16         //reserve space for encoded data 4*input/3\r
  17         encoded.reserve((4L*data.size())/3L);\r
  18         while(currentdatapos<data.size())\r
  19         {\r
  20                 encoded.push_back(base64chars[(data[currentdatapos]>>2 & 0x3F)]);\r
  21                 if(currentdatapos+1<data.size())\r
  22                 {\r
  23                         encoded.push_back(base64chars[(data[currentdatapos]<<4 & 0x30) | (data[currentdatapos+1]>>4 & 0x0F)]);\r
  24                         if(currentdatapos+2<data.size())\r
  25                         {\r
  26                                 encoded.push_back(base64chars[(data[currentdatapos+1]<<2 & 0x3C) | (data[currentdatapos+2]>>6 & 0x03)]);\r
  27                                 encoded.push_back(base64chars[(data[currentdatapos+2] & 0x3F)]);\r
  28                         }\r
  29                         else\r
  30                         {\r
  31                                 encoded.push_back(base64chars[(data[currentdatapos+1]<<2 & 0x3C)]);\r
  32                                 encoded.append("=");\r
  33                         }\r
  34                 }\r
  35                 else\r
  36                 {\r
  37                         encoded.push_back(base64chars[(data[currentdatapos]<<4 & 0x30)]);\r
  38                         encoded.append("==");\r
  39                 }\r
  40                 currentdatapos+=3;\r
  41         }\r
  42         return true;\r
  43 }\r
  44 \r
  45 const bool Decode(const std::string &encoded, std::vector<unsigned char> &data)\r
  46 {\r
  47         std::string::size_type charpos=0;\r
  48         std::string::size_type encodedpos=0;\r
  49         unsigned char currentbyte=0;\r
  50 \r
  51         // reserve space for decoded data (encoded size*3/4)\r
  52         if(encoded.size()>1)\r
  53         {\r
  54                 data.reserve((encoded.size()*3)/4);\r
  55         }\r
  56 \r
  57         // loop while encoded pos fits in current size\r
  58         while(encodedpos+3<encoded.size())\r
  59         {\r
  60                 currentbyte=0;\r
  61                 charpos=base64chars.find(encoded[encodedpos]);\r
  62                 if(charpos==std::string::npos)\r
  63                 {\r
  64                         return false;\r
  65                 }\r
  66                 currentbyte=(charpos<<2 & 0xFC);\r
  67                 charpos=base64chars.find(encoded[encodedpos+1]);\r
  68                 if(charpos==std::string::npos)\r
  69                 {\r
  70                         return false;\r
  71                 }\r
  72                 currentbyte|=(charpos>>4 & 0x03);\r
  73                 data.push_back(currentbyte);\r
  74                 currentbyte=(charpos<<4 & 0xF0);\r
  75 \r
  76                 if(encoded[encodedpos+2]!='=')\r
  77                 {\r
  78                         charpos=base64chars.find(encoded[encodedpos+2]);\r
  79                         if(charpos==std::string::npos)\r
  80                         {\r
  81                                 return false;\r
  82                         }\r
  83                         currentbyte|=(charpos>>2 & 0x0F);\r
  84                         data.push_back(currentbyte);\r
  85                         currentbyte=(charpos<<6 & 0xC0);\r
  86                 }\r
  87                 \r
  88                 if(encoded[encodedpos+2]!='=')\r
  89                 {\r
  90                         charpos=base64chars.find(encoded[encodedpos+3]);\r
  91                         if(charpos==std::string::npos)\r
  92                         {\r
  93                                 return false;\r
  94                         }\r
  95                         currentbyte|=(charpos & 0x3F);\r
  96                         data.push_back(currentbyte);\r
  97                 }\r
  98 \r
  99                 encodedpos+=4;\r
 100         }\r
 101 \r
 102         return true;\r
 103 }\r
 104 \r
 105 }       // namespace\r