base64.h c++

 #include "  
 static const std::string base64_chars =   
 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"  
 "abcdefghijklmnopqrstuvwxyz"  
 "0123456789+/";  
 static inline bool is_base64(unsigned char c) {  
      return (isalnum(c) || (c == '+') || (c == '/'));  
 }  
 std::string base64_encode(unsigned char const* bytes_to_encode, unsigned int in_len) {  
      std::string ret;  
      int i = 0;  
      int j = 0;  
      unsigned char char_array_3[3];  
      unsigned char 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 base64_decode(std::string const& encoded_string) {  
      size_t in_len = encoded_string.size();  
      size_t i = 0;  
      size_t j = 0;  
      int in_ = 0;  
      unsigned char 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<unsigned char>(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<unsigned char>(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;  
 }