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Diffstat (limited to 'src/curve_client.cpp')
| -rw-r--r-- | src/curve_client.cpp | 410 |
1 files changed, 410 insertions, 0 deletions
diff --git a/src/curve_client.cpp b/src/curve_client.cpp new file mode 100644 index 0000000..f832466 --- /dev/null +++ b/src/curve_client.cpp @@ -0,0 +1,410 @@ +/* + Copyright (c) 2007-2013 Contributors as noted in the AUTHORS file + + This file is part of 0MQ. + + 0MQ is free software; you can redistribute it and/or modify it under + the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 3 of the License, or + (at your option) any later version. + + 0MQ 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 "platform.hpp" + +#ifdef HAVE_LIBSODIUM + +#include <sodium.h> + +#ifdef ZMQ_HAVE_WINDOWS +#include "windows.hpp" +#endif + +#include "msg.hpp" +#include "session_base.hpp" +#include "err.hpp" +#include "curve_client.hpp" +#include "wire.hpp" + +zmq::curve_client_t::curve_client_t (const options_t &options_) : + mechanism_t (options_), + state (send_hello) +{ + memcpy (public_key, options_.curve_public_key, crypto_box_PUBLICKEYBYTES); + memcpy (secret_key, options_.curve_secret_key, crypto_box_SECRETKEYBYTES); + memcpy (server_key, options_.curve_server_key, crypto_box_PUBLICKEYBYTES); + + // Generate short-term key pair + const int rc = crypto_box_keypair (cn_public, cn_secret); + zmq_assert (rc == 0); +} + +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_) +{ + int rc = 0; + + switch (state) { + case expect_welcome: + rc = process_welcome (msg_); + if (rc == 0) + state = send_initiate; + break; + case expect_ready: + rc = process_ready (msg_); + if (rc == 0) + state = connected; + break; + default: + errno = EPROTO; + rc = -1; + break; + } + 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); + + uint8_t flags = 0; + if (msg_->flags () & msg_t::more) + flags |= 0x01; + + uint8_t message_nonce [crypto_box_NONCEBYTES]; + memcpy (message_nonce, "CurveZMQMESSAGEC", 16); + memcpy (message_nonce + 16, &cn_nonce, 8); + + const size_t mlen = crypto_box_ZEROBYTES + 1 + msg_->size (); + + 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, &cn_nonce, 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_client_t::decode (msg_t *msg_) +{ + zmq_assert (state == connected); + + if (msg_->size () < 33) { + errno = EPROTO; + return -1; + } + + const uint8_t *message = static_cast <uint8_t *> (msg_->data ()); + if (memcmp (message, "\x07MESSAGE", 8)) { + errno = EPROTO; + return -1; + } + + uint8_t message_nonce [crypto_box_NONCEBYTES]; + memcpy (message_nonce, "CurveZMQMESSAGES", 16); + memcpy (message_nonce + 16, message + 8, 8); + + 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); + + int 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); + + memcpy (msg_->data (), + message_plaintext + crypto_box_ZEROBYTES + 1, + msg_->size ()); + } + else + errno = EPROTO; + + free (message_plaintext); + free (message_box); + + return rc; +} + +bool zmq::curve_client_t::is_handshake_complete () const +{ + return state == connected; +} + +int zmq::curve_client_t::produce_hello (msg_t *msg_) +{ + uint8_t hello_nonce [crypto_box_NONCEBYTES]; + uint8_t hello_plaintext [crypto_box_ZEROBYTES + 64]; + uint8_t hello_box [crypto_box_BOXZEROBYTES + 80]; + + // Prepare the full nonce + memcpy (hello_nonce, "CurveZMQHELLO---", 16); + memcpy (hello_nonce + 16, &cn_nonce, 8); + + // Create Box [64 * %x0](C'->S) + memset (hello_plaintext, 0, sizeof hello_plaintext); + + int rc = crypto_box (hello_box, hello_plaintext, + sizeof hello_plaintext, + hello_nonce, server_key, cn_secret); + zmq_assert (rc == 0); + + rc = msg_->init_size (200); + errno_assert (rc == 0); + uint8_t *hello = static_cast <uint8_t *> (msg_->data ()); + + memcpy (hello, "\x05HELLO", 6); + // CurveZMQ major and minor version numbers + memcpy (hello + 6, "\1\0", 2); + // Anti-amplification padding + memset (hello + 8, 0, 72); + // Client public connection key + memcpy (hello + 80, cn_public, crypto_box_PUBLICKEYBYTES); + // Short nonce, prefixed by "CurveZMQHELLO---" + memcpy (hello + 112, hello_nonce + 16, 8); + // Signature, Box [64 * %x0](C'->S) + memcpy (hello + 120, hello_box + crypto_box_BOXZEROBYTES, 80); + + cn_nonce++; + + return 0; +} + +int zmq::curve_client_t::process_welcome (msg_t *msg_) +{ + if (msg_->size () != 168) { + errno = EPROTO; + return -1; + } + + const uint8_t * welcome = static_cast <uint8_t *> (msg_->data ()); + if (memcmp (welcome, "\x07WELCOME", 8)) { + errno = EPROTO; + return -1; + } + + uint8_t welcome_nonce [crypto_box_NONCEBYTES]; + uint8_t welcome_plaintext [crypto_box_ZEROBYTES + 128]; + uint8_t welcome_box [crypto_box_BOXZEROBYTES + 144]; + + // Open Box [S' + cookie](C'->S) + memset (welcome_box, 0, crypto_box_BOXZEROBYTES); + memcpy (welcome_box + crypto_box_BOXZEROBYTES, welcome + 24, 144); + + memcpy (welcome_nonce, "WELCOME-", 8); + memcpy (welcome_nonce + 8, welcome + 8, 16); + + int rc = crypto_box_open (welcome_plaintext, welcome_box, + sizeof welcome_box, + welcome_nonce, server_key, cn_secret); + if (rc != 0) { + errno = EPROTO; + return -1; + } + + memcpy (cn_server, welcome_plaintext + crypto_box_ZEROBYTES, 32); + memcpy (cn_cookie, welcome_plaintext + crypto_box_ZEROBYTES + 32, 16 + 80); + + // Message independent precomputation + rc = crypto_box_beforenm (cn_precom, cn_server, cn_secret); + zmq_assert (rc == 0); + + return 0; +} + +int zmq::curve_client_t::produce_initiate (msg_t *msg_) +{ + uint8_t vouch_nonce [crypto_box_NONCEBYTES]; + uint8_t vouch_plaintext [crypto_box_ZEROBYTES + 64]; + uint8_t vouch_box [crypto_box_BOXZEROBYTES + 80]; + + // Create vouch = Box [C',S](C->S') + memset (vouch_plaintext, 0, crypto_box_ZEROBYTES); + memcpy (vouch_plaintext + crypto_box_ZEROBYTES, cn_public, 32); + memcpy (vouch_plaintext + crypto_box_ZEROBYTES + 32, server_key, 32); + + memcpy (vouch_nonce, "VOUCH---", 8); + randombytes (vouch_nonce + 8, 16); + + int rc = crypto_box (vouch_box, vouch_plaintext, + sizeof vouch_plaintext, + vouch_nonce, cn_server, secret_key); + zmq_assert (rc == 0); + + // Assume here that metadata is limited to 256 bytes + uint8_t initiate_nonce [crypto_box_NONCEBYTES]; + uint8_t initiate_plaintext [crypto_box_ZEROBYTES + 128 + 256]; + uint8_t initiate_box [crypto_box_BOXZEROBYTES + 144 + 256]; + + // Create Box [C + vouch + metadata](C'->S') + memset (initiate_plaintext, 0, crypto_box_ZEROBYTES); + memcpy (initiate_plaintext + crypto_box_ZEROBYTES, + public_key, 32); + memcpy (initiate_plaintext + crypto_box_ZEROBYTES + 32, + vouch_nonce + 8, 16); + memcpy (initiate_plaintext + crypto_box_ZEROBYTES + 48, + vouch_box + crypto_box_BOXZEROBYTES, 80); + + // Metadata starts after vouch + uint8_t *ptr = initiate_plaintext + crypto_box_ZEROBYTES + 128; + + // Add socket type property + const char *socket_type = socket_type_string (options.type); + ptr += add_property (ptr, "Socket-Type", socket_type, strlen (socket_type)); + + // Add identity property + if (options.type == ZMQ_REQ + || options.type == ZMQ_DEALER + || options.type == ZMQ_ROUTER) + ptr += add_property (ptr, "Identity", + options.identity, options.identity_size); + + const size_t mlen = ptr - initiate_plaintext; + + memcpy (initiate_nonce, "CurveZMQINITIATE", 16); + memcpy (initiate_nonce + 16, &cn_nonce, 8); + + rc = crypto_box (initiate_box, initiate_plaintext, + mlen, initiate_nonce, cn_server, cn_secret); + zmq_assert (rc == 0); + + rc = msg_->init_size (113 + mlen - crypto_box_BOXZEROBYTES); + errno_assert (rc == 0); + + uint8_t *initiate = static_cast <uint8_t *> (msg_->data ()); + + memcpy (initiate, "\x08INITIATE", 9); + // Cookie provided by the server in the WELCOME command + memcpy (initiate + 9, cn_cookie, 96); + // Short nonce, prefixed by "CurveZMQINITIATE" + memcpy (initiate + 105, &cn_nonce, 8); + // Box [C + vouch + metadata](C'->S') + memcpy (initiate + 113, initiate_box + crypto_box_BOXZEROBYTES, + mlen - crypto_box_BOXZEROBYTES); + cn_nonce++; + + return 0; +} + +int zmq::curve_client_t::process_ready (msg_t *msg_) +{ + if (msg_->size () < 30) { + errno = EPROTO; + return -1; + } + + const uint8_t *ready = static_cast <uint8_t *> (msg_->data ()); + if (memcmp (ready, "\x05READY", 6)) { + 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 [crypto_box_ZEROBYTES + 256]; + uint8_t ready_box [crypto_box_BOXZEROBYTES + 16 + 256]; + + memset (ready_box, 0, crypto_box_BOXZEROBYTES); + memcpy (ready_box + crypto_box_BOXZEROBYTES, + ready + 14, clen - crypto_box_BOXZEROBYTES); + + memcpy (ready_nonce, "CurveZMQREADY---", 16); + memcpy (ready_nonce + 16, ready + 6, 8); + + int rc = crypto_box_open_afternm (ready_plaintext, ready_box, + clen, ready_nonce, cn_precom); + + if (rc != 0) { + errno = EPROTO; + return -1; + } + + rc = parse_metadata (ready_plaintext + crypto_box_ZEROBYTES, + clen - crypto_box_ZEROBYTES); + return rc; +} + +#endif |