# Pastebin 9PKybAkK
size_t base64Encode(const char* data, size_t length, char** result){
    size_t lengthOfEncodedData = length*4/3 + (length%3?0:3) + 1;
    unsigned char * encodedData = (unsigned char *)calloc(lengthOfEncodedData, sizeof(unsigned char));
    lengthOfEncodedData = EVP_EncodeBlock(encodedData, data, length); // it includes NUL terminator 
    *result = encodedData;
    return lengthOfEncodedData; 
}