/*

 * This file is part of PowerDNS or dnsdist.

 * Copyright -- PowerDNS.COM B.V. and its contributors

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of version 2 of the GNU General Public License as

 * published by the Free Software Foundation.

 *

 * In addition, for the avoidance of any doubt, permission is granted to

 * link this program with OpenSSL and to (re)distribute the binaries

 * produced as the result of such linking.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 *

 * You should have received a copy of the GNU General Public License

 * along with this program; if not, write to the Free Software

 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "base64.hh"

#include <stdexcept>

#include <boost/scoped_array.hpp>

#include <openssl/bio.h>

#include <openssl/evp.h>

template<typename Container> int B64Decode(const std::string& src, Container& dst)

{

  if (src.empty() ) {

    dst.clear();

    return 0;

  }

  int dlen = ( src.length() * 6 + 7 ) / 8 ;

  ssize_t olen = 0;

  dst.resize(dlen);

  BIO *bio, *b64;

  bio = BIO_new(BIO_s_mem());

  BIO_write(bio, src.c_str(), src.length());

  b64 = BIO_new(BIO_f_base64());

  bio = BIO_push(b64, bio);

  BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL);

  olen = BIO_read(b64, &dst.at(0), dlen);

  if ((olen == 0 || olen == -1) && BIO_should_retry(bio)) {

    BIO_free_all(bio);

    throw std::runtime_error("BIO_read failed to read all data from memory buffer");

  }

  BIO_free_all(bio);

  if (olen > 0) {

    dst.resize(olen);

    return 0;

  }

  return -1;

}

template int B64Decode<std::string>(const std::string& strInput, std::string& strOutput);

std::string Base64Encode(const std::string& src)

{

  if (!src.empty()) {

    size_t olen = 0;

    BIO *bio, *b64;

    b64 = BIO_new(BIO_f_base64());

    bio = BIO_new(BIO_s_mem());

    bio = BIO_push(b64, bio);

    BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL);

    int bioWriteRet = BIO_write(bio, src.c_str(), src.length());

    if (bioWriteRet < 0 || (size_t) bioWriteRet != src.length()) {

      BIO_free_all(bio);

      throw std::runtime_error("BIO_write failed to write all data to memory buffer");

    }

    (void)BIO_flush(bio);

    char* pp;

    std::string out;

    olen = BIO_get_mem_data(bio, &pp);

    if (olen > 0) {

      out = std::string(pp, olen);

    }

    BIO_free_all(bio);

    return out;

  }

  return "";

}

#if 0

#include <iostream>

int main() {

  std::string in = "PowerDNS Test String 1";

  std::string out = Base64Encode(in);

  std::cout << out << std::endl;

  if (out != "UG93ZXJETlMgVGVzdCBTdHJpbmcgMQ==") {

    std::cerr << "output did not match expected data" << std::endl;

  }

  std::string roundtrip;

  B64Decode(out, roundtrip);

  std::cout << roundtrip << std::endl;

  if (roundtrip != in) {

    std::cerr << "roundtripped data did not match input data" << std::endl;

  }

  return 0;

}

#endif