File content as of revision 0:0791c1fece8e:

#include "iputil.h"

unsigned int base64enc_len(const char *str) {
  return (((strlen(str)-1)/3)+1)<<2;
}

void base64enc(const char *input, unsigned int length, char *output) {
  static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  unsigned int c, c1, c2, c3;
  for(unsigned int i = 0, j = 0; i<length; i+=3,j+=4) {
    c1 = ((((unsigned char)*((unsigned char *)&input[i]))));
    c2 = (length>i+1)?((((unsigned char)*((unsigned char *)&input[i+1])))):0;
    c3 = (length>i+2)?((((unsigned char)*((unsigned char *)&input[i+2])))):0;

    c = ((c1 & 0xFC) >> 2);
    output[j+0] = base64[c];
    c = ((c1 & 0x03) << 4) | ((c2 & 0xF0) >> 4);
    output[j+1] = base64[c];
    c = ((c2 & 0x0F) << 2) | ((c3 & 0xC0) >> 6);
    output[j+2] = (length>i+1)?base64[c]:'=';
    c = (c3 & 0x3F);
    output[j+3] = (length>i+2)?base64[c]:'=';
  }
  output[(((length-1)/3)+1)<<2] = '\0';
}