1 /*
2 Copyright (c) 2007-2016 Contributors as noted in the AUTHORS file
3
4 This file is part of libzmq, the ZeroMQ core engine in C++.
5
6 libzmq is free software; you can redistribute it and/or modify it under
7 the terms of the GNU Lesser General Public License (LGPL) as published
8 by the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
10
11 As a special exception, the Contributors give you permission to link
12 this library with independent modules to produce an executable,
13 regardless of the license terms of these independent modules, and to
14 copy and distribute the resulting executable under terms of your choice,
15 provided that you also meet, for each linked independent module, the
16 terms and conditions of the license of that module. An independent
17 module is a module which is not derived from or based on this library.
18 If you modify this library, you must extend this exception to your
19 version of the library.
20
21 libzmq is distributed in the hope that it will be useful, but WITHOUT
22 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
23 FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
24 License for more details.
25
26 You should have received a copy of the GNU Lesser General Public License
27 along with this program. If not, see <http://www.gnu.org/licenses/>.
28 */
29
30 #include "precompiled.hpp"
31 #include "macros.hpp"
32
33 #ifdef ZMQ_HAVE_CURVE
34
35 #include "msg.hpp"
36 #include "session_base.hpp"
37 #include "err.hpp"
38 #include "curve_client.hpp"
39 #include "wire.hpp"
40 #include "curve_client_tools.hpp"
41 #include "secure_allocator.hpp"
42
curve_client_t(session_base_t * session_,const options_t & options_,const bool downgrade_sub_)43 zmq::curve_client_t::curve_client_t (session_base_t *session_,
44 const options_t &options_,
45 const bool downgrade_sub_) :
46 mechanism_base_t (session_, options_),
47 curve_mechanism_base_t (session_,
48 options_,
49 "CurveZMQMESSAGEC",
50 "CurveZMQMESSAGES",
51 downgrade_sub_),
52 _state (send_hello),
53 _tools (options_.curve_public_key,
54 options_.curve_secret_key,
55 options_.curve_server_key)
56 {
57 }
58
~curve_client_t()59 zmq::curve_client_t::~curve_client_t ()
60 {
61 }
62
next_handshake_command(msg_t * msg_)63 int zmq::curve_client_t::next_handshake_command (msg_t *msg_)
64 {
65 int rc = 0;
66
67 switch (_state) {
68 case send_hello:
69 rc = produce_hello (msg_);
70 if (rc == 0)
71 _state = expect_welcome;
72 break;
73 case send_initiate:
74 rc = produce_initiate (msg_);
75 if (rc == 0)
76 _state = expect_ready;
77 break;
78 default:
79 errno = EAGAIN;
80 rc = -1;
81 }
82 return rc;
83 }
84
process_handshake_command(msg_t * msg_)85 int zmq::curve_client_t::process_handshake_command (msg_t *msg_)
86 {
87 const unsigned char *msg_data =
88 static_cast<unsigned char *> (msg_->data ());
89 const size_t msg_size = msg_->size ();
90
91 int rc = 0;
92 if (curve_client_tools_t::is_handshake_command_welcome (msg_data, msg_size))
93 rc = process_welcome (msg_data, msg_size);
94 else if (curve_client_tools_t::is_handshake_command_ready (msg_data,
95 msg_size))
96 rc = process_ready (msg_data, msg_size);
97 else if (curve_client_tools_t::is_handshake_command_error (msg_data,
98 msg_size))
99 rc = process_error (msg_data, msg_size);
100 else {
101 session->get_socket ()->event_handshake_failed_protocol (
102 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_UNEXPECTED_COMMAND);
103 errno = EPROTO;
104 rc = -1;
105 }
106
107 if (rc == 0) {
108 rc = msg_->close ();
109 errno_assert (rc == 0);
110 rc = msg_->init ();
111 errno_assert (rc == 0);
112 }
113
114 return rc;
115 }
116
encode(msg_t * msg_)117 int zmq::curve_client_t::encode (msg_t *msg_)
118 {
119 zmq_assert (_state == connected);
120 return curve_mechanism_base_t::encode (msg_);
121 }
122
decode(msg_t * msg_)123 int zmq::curve_client_t::decode (msg_t *msg_)
124 {
125 zmq_assert (_state == connected);
126 return curve_mechanism_base_t::decode (msg_);
127 }
128
status() const129 zmq::mechanism_t::status_t zmq::curve_client_t::status () const
130 {
131 if (_state == connected)
132 return mechanism_t::ready;
133 if (_state == error_received)
134 return mechanism_t::error;
135
136 return mechanism_t::handshaking;
137 }
138
produce_hello(msg_t * msg_)139 int zmq::curve_client_t::produce_hello (msg_t *msg_)
140 {
141 int rc = msg_->init_size (200);
142 errno_assert (rc == 0);
143
144 rc = _tools.produce_hello (msg_->data (), get_and_inc_nonce ());
145 if (rc == -1) {
146 session->get_socket ()->event_handshake_failed_protocol (
147 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
148
149 // TODO this is somewhat inconsistent: we call init_size, but we may
150 // not close msg_; i.e. we assume that msg_ is initialized but empty
151 // (if it were non-empty, calling init_size might cause a leak!)
152
153 // msg_->close ();
154 return -1;
155 }
156
157 return 0;
158 }
159
process_welcome(const uint8_t * msg_data_,size_t msg_size_)160 int zmq::curve_client_t::process_welcome (const uint8_t *msg_data_,
161 size_t msg_size_)
162 {
163 const int rc = _tools.process_welcome (msg_data_, msg_size_,
164 get_writable_precom_buffer ());
165
166 if (rc == -1) {
167 session->get_socket ()->event_handshake_failed_protocol (
168 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
169
170 errno = EPROTO;
171 return -1;
172 }
173
174 _state = send_initiate;
175
176 return 0;
177 }
178
produce_initiate(msg_t * msg_)179 int zmq::curve_client_t::produce_initiate (msg_t *msg_)
180 {
181 const size_t metadata_length = basic_properties_len ();
182 std::vector<unsigned char, secure_allocator_t<unsigned char> >
183 metadata_plaintext (metadata_length);
184
185 add_basic_properties (&metadata_plaintext[0], metadata_length);
186
187 const size_t msg_size =
188 113 + 128 + crypto_box_BOXZEROBYTES + metadata_length;
189 int rc = msg_->init_size (msg_size);
190 errno_assert (rc == 0);
191
192 rc = _tools.produce_initiate (msg_->data (), msg_size, get_and_inc_nonce (),
193 &metadata_plaintext[0], metadata_length);
194
195 if (-1 == rc) {
196 session->get_socket ()->event_handshake_failed_protocol (
197 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
198
199 // TODO see comment in produce_hello
200 return -1;
201 }
202
203 return 0;
204 }
205
process_ready(const uint8_t * msg_data_,size_t msg_size_)206 int zmq::curve_client_t::process_ready (const uint8_t *msg_data_,
207 size_t msg_size_)
208 {
209 if (msg_size_ < 30) {
210 session->get_socket ()->event_handshake_failed_protocol (
211 session->get_endpoint (),
212 ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_READY);
213 errno = EPROTO;
214 return -1;
215 }
216
217 const size_t clen = (msg_size_ - 14) + crypto_box_BOXZEROBYTES;
218
219 uint8_t ready_nonce[crypto_box_NONCEBYTES];
220 std::vector<uint8_t, secure_allocator_t<uint8_t> > ready_plaintext (
221 crypto_box_ZEROBYTES + clen);
222 std::vector<uint8_t> ready_box (crypto_box_BOXZEROBYTES + 16 + clen);
223
224 std::fill (ready_box.begin (), ready_box.begin () + crypto_box_BOXZEROBYTES,
225 0);
226 memcpy (&ready_box[crypto_box_BOXZEROBYTES], msg_data_ + 14,
227 clen - crypto_box_BOXZEROBYTES);
228
229 memcpy (ready_nonce, "CurveZMQREADY---", 16);
230 memcpy (ready_nonce + 16, msg_data_ + 6, 8);
231 set_peer_nonce (get_uint64 (msg_data_ + 6));
232
233 int rc = crypto_box_open_afternm (&ready_plaintext[0], &ready_box[0], clen,
234 ready_nonce, get_precom_buffer ());
235
236 if (rc != 0) {
237 session->get_socket ()->event_handshake_failed_protocol (
238 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_CRYPTOGRAPHIC);
239 errno = EPROTO;
240 return -1;
241 }
242
243 rc = parse_metadata (&ready_plaintext[crypto_box_ZEROBYTES],
244 clen - crypto_box_ZEROBYTES);
245
246 if (rc == 0)
247 _state = connected;
248 else {
249 session->get_socket ()->event_handshake_failed_protocol (
250 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_INVALID_METADATA);
251 errno = EPROTO;
252 }
253
254 return rc;
255 }
256
process_error(const uint8_t * msg_data_,size_t msg_size_)257 int zmq::curve_client_t::process_error (const uint8_t *msg_data_,
258 size_t msg_size_)
259 {
260 if (_state != expect_welcome && _state != expect_ready) {
261 session->get_socket ()->event_handshake_failed_protocol (
262 session->get_endpoint (), ZMQ_PROTOCOL_ERROR_ZMTP_UNEXPECTED_COMMAND);
263 errno = EPROTO;
264 return -1;
265 }
266 if (msg_size_ < 7) {
267 session->get_socket ()->event_handshake_failed_protocol (
268 session->get_endpoint (),
269 ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_ERROR);
270 errno = EPROTO;
271 return -1;
272 }
273 const size_t error_reason_len = static_cast<size_t> (msg_data_[6]);
274 if (error_reason_len > msg_size_ - 7) {
275 session->get_socket ()->event_handshake_failed_protocol (
276 session->get_endpoint (),
277 ZMQ_PROTOCOL_ERROR_ZMTP_MALFORMED_COMMAND_ERROR);
278 errno = EPROTO;
279 return -1;
280 }
281 const char *error_reason = reinterpret_cast<const char *> (msg_data_) + 7;
282 handle_error_reason (error_reason, error_reason_len);
283 _state = error_received;
284 return 0;
285 }
286
287 #endif
288