Base64.cpp

#include "Base64.h"

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


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

std::string EncodeBase64(const string& s)
{
	const char* bytes_to_encode = s.c_str();
	unsigned int in_len = s.length();
  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;

}