//    OpenVPN -- An application to securely tunnel IP networks
//               over a single port, with support for SSL/TLS-based
//               session authentication and key exchange,
//               packet encryption, packet authentication, and
//               packet compression.
//
//    Copyright (C) 2017-2018 OpenVPN Technologies, Inc.
//
//    This program is free software: you can redistribute it and/or modify
//    it under the terms of the GNU General Public License Version 3
//    as published by the Free Software Foundation.
//
//    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 in the COPYING file.
//    If not, see <http://www.gnu.org/licenses/>.

// Wrap the mbedTLS PEM API defined in <mbedtls/pem.h> so
// that it can be used as part of the crypto layer of the OpenVPN core.

#ifndef OPENVPN_MBEDTLS_UTIL_PEM_H
#define OPENVPN_MBEDTLS_UTIL_PEM_H

#include <mbedtls/pem.h>

namespace openvpn {
    class MbedTLSPEM
    {
    public:
      static bool pem_encode(BufferAllocated& dst, const unsigned char *src,
			     size_t src_len, const std::string& key_name)
      {
	std::string header = "-----BEGIN " + key_name + "-----\n";
	std::string footer = "-----END " + key_name + "-----\n";
	size_t out_len = 0;

	int ret = mbedtls_pem_write_buffer(header.c_str(), footer.c_str(),
					   src, src_len, dst.data(),
					   dst.max_size(), &out_len);
	if (ret == 0)
	  dst.set_size(out_len);
	else
	{
	  char buf[128];
	  mbedtls_strerror(ret, buf, 128);
	  OPENVPN_LOG("mbedtls_pem_write_buffer error: " <<  buf);
	}

	return (ret == 0);
      }

      static bool pem_decode(BufferAllocated& dst, const char *src,
			     size_t src_len, const std::string& key_name)
      {
	std::string header = "-----BEGIN " + key_name + "-----";
	std::string footer = "-----END " + key_name + "-----";
	mbedtls_pem_context ctx = { };
	size_t out_len = 0;

	int ret = mbedtls_pem_read_buffer(&ctx, header.c_str(), footer.c_str(),
					  (unsigned char *)src, nullptr, 0,
					  &out_len);
	if (ret == 0)
	  dst.init(ctx.buf, ctx.buflen, BufferAllocated::DESTRUCT_ZERO);

	mbedtls_pem_free(&ctx);

	return (ret == 0);
      }
    };
};

#endif /* OPENVPN_MBEDTLS_UTIL_PEM_H */