text: /*
      Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
  
      This file is part of libzmq, the ZeroMQ core engine in C++.
  
      libzmq is free software; you can redistribute it and/or modify it under
      the terms of the GNU Lesser General Public License (LGPL) as published
      by the Free Software Foundation; either version 3 of the License, or
      (at your option) any later version.
  
      As a special exception, the Contributors give you permission to link
      this library with independent modules to produce an executable,
      regardless of the license terms of these independent modules, and to
      copy and distribute the resulting executable under terms of your choice,
      provided that you also meet, for each linked independent module, the
      terms and conditions of the license of that module. An independent
      module is a module which is not derived from or based on this library.
      If you modify this library, you must extend this exception to your
      version of the library.
  
      libzmq 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 Lesser General Public
      License for more details.
  
      You should have received a copy of the GNU Lesser General Public License
      along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
  
  #include "precompiled.hpp"
  #include "macros.hpp"
  
  #ifdef ZMQ_HAVE_CURVE
  
  #include "msg.hpp"
  #include "session_base.hpp"
  #include "err.hpp"
  #include "curve_client.hpp"
  #include "wire.hpp"
  #include "curve_client_tools.hpp"
  
  zmq::curve_client_t::curve_client_t (session_base_t *session_,
                                       const options_t &options_) :
      mechanism_base_t (session_, options_),
      curve_mechanism_base_t (
        session_, options_, "CurveZMQMESSAGEC", "CurveZMQMESSAGES"),
      _state (send_hello),
      _tools (options_.curve_public_key,
              options_.curve_secret_key,
              options_.curve_server_key)
  {
  }
  
  zmq::curve_client_t::~curve_client_t ()
  {
  }
  
  int zmq::curve_client_t::next_handshake_command (msg_t *msg_)
  {
      int rc = 0;
  
      switch (_state) {
          case send_hello:
              rc = produce_hello (msg_);
              if (rc == 0)
                  _state = expect_welcome;
              break;
          case send_initiate:
              rc = produce_initiate (msg_);
              if (rc == 0)
                  _state = expect_ready;
              break;
          default:
              errno = EAGAIN;
              rc = -1;
      }
      return rc;
  }
  
  int zmq::curve_client_t::process_handshake_command (msg_t *msg_)
  {
      const unsigned char *msg_data =
        static_cast<unsigned char *> (msg_->data ());
      const size_t msg_size = msg_->size ();
  
      int rc = 0;
      if (curve_client_tools_t::is_handshake_command_welcome (msg_data, msg_size))
          rc = process_welcome (msg_data, msg_size);
      else if (curve_client_tools_t::is_handshake_command_ready (msg_data,
                                                                 msg_size))
          rc = process_ready (msg_data, msg_size);
      else if (curve_client_tools_t::is_handshake_command_error (msg_data,
                                                                 msg_size))
          rc = process_error (msg_data, msg_size);
      else {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_UNEXPECTED_COMMAND);
          errno = EPROTO;
          rc = -1;
      }
  
      if (rc == 0) {
          rc = msg_->close ();
          errno_assert (rc == 0);
          rc = msg_->init ();
          errno_assert (rc == 0);
      }
  
      return rc;
  }
  
  int zmq::curve_client_t::encode (msg_t *msg_)
  {
      zmq_assert (_state == connected);
      return curve_mechanism_base_t::encode (msg_);
  }
  
  int zmq::curve_client_t::decode (msg_t *msg_)
  {
      zmq_assert (_state == connected);
      return curve_mechanism_base_t::decode (msg_);
  }
  
  zmq::mechanism_t::status_t zmq::curve_client_t::status () const
  {
      if (_state == connected)
          return mechanism_t::ready;
      if (_state == error_received)
          return mechanism_t::error;
      else
          return mechanism_t::handshaking;
  }
  
  int zmq::curve_client_t::produce_hello (msg_t *msg_)
  {
      int rc = msg_->init_size (200);
      errno_assert (rc == 0);
  
      rc = _tools.produce_hello (msg_->data (), cn_nonce);
      if (rc == -1) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
  
          // TODO this is somewhat inconsistent: we call init_size, but we may
          // not close msg_; i.e. we assume that msg_ is initialized but empty
          // (if it were non-empty, calling init_size might cause a leak!)
  
          // msg_->close ();
          return -1;
      }
  
      cn_nonce++;
  
      return 0;
  }
  
  int zmq::curve_client_t::process_welcome (const uint8_t *msg_data_,
                                            size_t msg_size_)
  {
      int rc = _tools.process_welcome (msg_data_, msg_size_, cn_precom);
  
      if (rc == -1) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
  
          errno = EPROTO;
          return -1;
      }
  
      _state = send_initiate;
  
      return 0;
  }
  
  int zmq::curve_client_t::produce_initiate (msg_t *msg_)
  {
      const size_t metadata_length = basic_properties_len ();
      unsigned char *metadata_plaintext =
        static_cast<unsigned char *> (malloc (metadata_length));
      alloc_assert (metadata_plaintext);
  
      add_basic_properties (metadata_plaintext, metadata_length);
  
      size_t msg_size = 113 + 128 + crypto_box_BOXZEROBYTES + metadata_length;
      int rc = msg_->init_size (msg_size);
      errno_assert (rc == 0);
  
      rc = _tools.produce_initiate (msg_->data (), msg_size, cn_nonce,
                                    metadata_plaintext, metadata_length);
  
      free (metadata_plaintext);
  
      if (-1 == rc) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
  
          // TODO see comment in produce_hello
          return -1;
      }
  
      cn_nonce++;
  
      return 0;
  }
  
  int zmq::curve_client_t::process_ready (const uint8_t *msg_data_,
                                          size_t msg_size_)
  {
      if (msg_size_ < 30) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (),
            ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_READY);
          errno = EPROTO;
          return -1;
      }
  
      const size_t clen = (msg_size_ - 14) + crypto_box_BOXZEROBYTES;
  
      uint8_t ready_nonce[crypto_box_NONCEBYTES];
      uint8_t *ready_plaintext =
        static_cast<uint8_t *> (malloc (crypto_box_ZEROBYTES + clen));
      alloc_assert (ready_plaintext);
      uint8_t *ready_box =
        static_cast<uint8_t *> (malloc (crypto_box_BOXZEROBYTES + 16 + clen));
      alloc_assert (ready_box);
  
      memset (ready_box, 0, crypto_box_BOXZEROBYTES);
      memcpy (ready_box + crypto_box_BOXZEROBYTES, msg_data_ + 14,
              clen - crypto_box_BOXZEROBYTES);
  
      memcpy (ready_nonce, "CurveZMQREADY---", 16);
      memcpy (ready_nonce + 16, msg_data_ + 6, 8);
      cn_peer_nonce = get_uint64 (msg_data_ + 6);
  
      int rc = crypto_box_open_afternm (ready_plaintext, ready_box, clen,
                                        ready_nonce, cn_precom);
      free (ready_box);
  
      if (rc != 0) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
          errno = EPROTO;
          return -1;
      }
  
      rc = parse_metadata (ready_plaintext + crypto_box_ZEROBYTES,
                           clen - crypto_box_ZEROBYTES);
      free (ready_plaintext);
  
      if (rc == 0)
          _state = connected;
      else {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_INVALID_METADATA);
          errno = EPROTO;
      }
  
      return rc;
  }
  
  int zmq::curve_client_t::process_error (const uint8_t *msg_data_,
                                          size_t msg_size_)
  {
      if (_state != expect_welcome && _state != expect_ready) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_UNEXPECTED_COMMAND);
          errno = EPROTO;
          return -1;
      }
      if (msg_size_ < 7) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (),
            ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_ERROR);
          errno = EPROTO;
          return -1;
      }
      const size_t error_reason_len = static_cast<size_t> (msg_data_[6]);
      if (error_reason_len > msg_size_ - 7) {
          session->get_socket ()->event_handshake_failed_protocol (
            session->get_endpoint (),
            ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_ERROR);
          errno = EPROTO;
          return -1;
      }
      const char *error_reason = reinterpret_cast<const char *> (msg_data_) + 7;
      handle_error_reason (error_reason, error_reason_len);
      _state = error_received;
      return 0;
  }
  
  #endif
  