/*
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 "curve_mechanism_base.hpp"
#include "msg.hpp"
#include "wire.hpp"
#include "session_base.hpp"
#ifdef ZMQ_HAVE_CURVE
zmq::curve_mechanism_base_t::curve_mechanism_base_t (
session_base_t *session_,
const options_t &options_,
const char *encode_nonce_prefix_,
const char *decode_nonce_prefix_) :
mechanism_base_t (session_, options_),
encode_nonce_prefix (encode_nonce_prefix_),
decode_nonce_prefix (decode_nonce_prefix_),
cn_nonce (1),
cn_peer_nonce (1)
{
}
int zmq::curve_mechanism_base_t::encode (msg_t *msg_)
{
const size_t mlen = crypto_box_ZEROBYTES + 1 + msg_->size ();
uint8_t message_nonce[crypto_box_NONCEBYTES];
memcpy (message_nonce, encode_nonce_prefix, 16);
put_uint64 (message_nonce + 16, cn_nonce);
uint8_t flags = 0;
if (msg_->flags () & msg_t::more)
flags |= 0x01;
if (msg_->flags () & msg_t::command)
flags |= 0x02;
uint8_t *message_plaintext = static_cast<uint8_t *> (malloc (mlen));
alloc_assert (message_plaintext);
memset (message_plaintext, 0, crypto_box_ZEROBYTES);
message_plaintext[crypto_box_ZEROBYTES] = flags;
memcpy (message_plaintext + crypto_box_ZEROBYTES + 1, msg_->data (),
msg_->size ());
uint8_t *message_box = static_cast<uint8_t *> (malloc (mlen));
alloc_assert (message_box);
int rc = crypto_box_afternm (message_box, message_plaintext, mlen,
message_nonce, cn_precom);
zmq_assert (rc == 0);
rc = msg_->close ();
zmq_assert (rc == 0);
rc = msg_->init_size (16 + mlen - crypto_box_BOXZEROBYTES);
zmq_assert (rc == 0);
uint8_t *message = static_cast<uint8_t *> (msg_->data ());
memcpy (message, "\x07MESSAGE", 8);
memcpy (message + 8, message_nonce + 16, 8);
memcpy (message + 16, message_box + crypto_box_BOXZEROBYTES,
mlen - crypto_box_BOXZEROBYTES);
free (message_plaintext);
free (message_box);
cn_nonce++;
return 0;
}
int zmq::curve_mechanism_base_t::decode (msg_t *msg_)
{
int rc = check_basic_command_structure (msg_);
if (rc == -1)
return -1;
const size_t size = msg_->size ();
const uint8_t *message = static_cast<uint8_t *> (msg_->data ());
if (size < 8 || memcmp (message, "\x07MESSAGE", 8)) {
session->get_socket ()->event_handshake_failed_protocol (
session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_UNEXPECTED_COMMAND);
errno = EPROTO;
return -1;
}
if (size < 33) {
session->get_socket ()->event_handshake_failed_protocol (
session->get_endpoint (),
ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_MESSAGE);
errno = EPROTO;
return -1;
}
uint8_t message_nonce[crypto_box_NONCEBYTES];
memcpy (message_nonce, decode_nonce_prefix, 16);
memcpy (message_nonce + 16, message + 8, 8);
uint64_t nonce = get_uint64 (message + 8);
if (nonce <= cn_peer_nonce) {
session->get_socket ()->event_handshake_failed_protocol (
session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_INVALID_SEQUENCE);
errno = EPROTO;
return -1;
}
cn_peer_nonce = nonce;
const size_t clen = crypto_box_BOXZEROBYTES + msg_->size () - 16;
uint8_t *message_plaintext = static_cast<uint8_t *> (malloc (clen));
alloc_assert (message_plaintext);
uint8_t *message_box = static_cast<uint8_t *> (malloc (clen));
alloc_assert (message_box);
memset (message_box, 0, crypto_box_BOXZEROBYTES);
memcpy (message_box + crypto_box_BOXZEROBYTES, message + 16,
msg_->size () - 16);
rc = crypto_box_open_afternm (message_plaintext, message_box, clen,
message_nonce, cn_precom);
if (rc == 0) {
rc = msg_->close ();
zmq_assert (rc == 0);
rc = msg_->init_size (clen - 1 - crypto_box_ZEROBYTES);
zmq_assert (rc == 0);
const uint8_t flags = message_plaintext[crypto_box_ZEROBYTES];
if (flags & 0x01)
msg_->set_flags (msg_t::more);
if (flags & 0x02)
msg_->set_flags (msg_t::command);
memcpy (msg_->data (), message_plaintext + crypto_box_ZEROBYTES + 1,
msg_->size ());
} else {
// CURVE I : connection key used for MESSAGE is wrong
session->get_socket ()->event_handshake_failed_protocol (
session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
errno = EPROTO;
}
free (message_plaintext);
free (message_box);
return rc;
}
#endif
↑ V512 A call of the 'memcpy' function will lead to underflow of the buffer 'message_nonce'.
↑ V522 There might be dereferencing of a potential null pointer 'message_plaintext'. Check lines: 159, 140.
↑ V575 The potential null pointer is passed into 'memset' function. Inspect the first argument. Check lines: 146, 143.
↑ V575 The potential null pointer is passed into 'memset' function. Inspect the first argument. Check lines: 69, 66.
↑ V769 The 'message_box' pointer in the 'message_box + 16' expression could be nullptr. In such case, resulting value will be senseless and it should not be used. Check lines: 91, 74.
↑ V730 Not all members of a class are initialized inside the constructor. Consider inspecting: cn_precom.
↑ V526 The 'memcmp' function returns 0 if corresponding buffers are equal. Consider examining the condition for mistakes.