char* base64_encode(char* plain) {

    char counts = 0;
    char buffer[3];
    char* cipher = malloc(strlen(plain) * 4 / 3 + 4);
    int i = 0, c = 0;

    for(i = 0; plain[i] != '\0'; i++) {
        buffer[counts++] = plain[i];
        if(counts == 3) {
            cipher[c++] = base46_map[buffer[0] >> 2];
            cipher[c++] = base46_map[((buffer[0] & 0x03) << 4) + (buffer[1] >> 4)];
            cipher[c++] = base46_map[((buffer[1] & 0x0f) << 2) + (buffer[2] >> 6)];
            cipher[c++] = base46_map[buffer[2] & 0x3f];
            counts = 0;
        }
    }

    if(counts > 0) {
        cipher[c++] = base46_map[buffer[0] >> 2];
        if(counts == 1) {
            cipher[c++] = base46_map[(buffer[0] & 0x03) << 4];
            cipher[c++] = '=';
        } else {                      // if counts == 2
            cipher[c++] = base46_map[((buffer[0] & 0x03) << 4) + (buffer[1] >> 4)];
            cipher[c++] = base46_map[(buffer[1] & 0x0f) << 2];
        }
        cipher[c++] = '=';
    }

    cipher[c] = '\0';   /* string padding character */
    return cipher;
}