Abstract security mechanism

src/null_mechanism.cpp

@@ -0,0 +1,152 @@
+/*
+    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 ZMQ_HAVE_WINDOWS
+#include "windows.hpp"
+#endif
+
+#include <stddef.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "err.hpp"
+#include "msg.hpp"
+#include "wire.hpp"
+#include "null_mechanism.hpp"
+
+zmq::null_mechanism_t::null_mechanism_t (const options_t &options_) : mechanism_t (options_),
+  ready_command_sent (false),
+  ready_command_received (false)
+{
+}
+
+zmq::null_mechanism_t::~null_mechanism_t ()
+{
+}
+
+int zmq::null_mechanism_t::next_handshake_message (msg_t *msg_)
+{
+    if (ready_command_sent) {
+        errno = EAGAIN;
+        return -1;
+    }
+
+    unsigned char * const command_buffer = (unsigned char *) malloc (512);
+    alloc_assert (command_buffer);
+
+    unsigned char *ptr = command_buffer;
+
+    //  Add mechanism string
+    memcpy (ptr, "READY   ", 8);
+    ptr += 8;
+
+    //  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 command_size = ptr - command_buffer;
+    const int rc = msg_->init_size (command_size);
+    errno_assert (rc == 0);
+    memcpy (msg_->data (), command_buffer, command_size);
+    free (command_buffer);
+
+    ready_command_sent = true;
+
+    return 0;
+}
+
+int zmq::null_mechanism_t::process_handshake_message (msg_t *msg_)
+{
+    if (ready_command_received) {
+        errno = EPROTO;
+        return -1;
+    }
+
+    const unsigned char *ptr =
+        static_cast <unsigned char *> (msg_->data ());
+    size_t bytes_left = msg_->size ();
+
+    if (bytes_left < 8 || memcmp (ptr, "READY   ", 8)) {
+        errno = EPROTO;
+        return -1;
+    }
+
+    ptr += 8;
+    bytes_left -= 8;
+
+    //  Parse the property list
+    while (bytes_left > 1) {
+        const size_t name_length = static_cast <size_t> (*ptr);
+        ptr += 1;
+        bytes_left -= 1;
+
+        if (bytes_left < name_length)
+            break;
+        const std::string name = std::string((const char *) ptr, name_length);
+        ptr += name_length;
+        bytes_left -= name_length;
+
+        if (bytes_left < 4)
+            break;
+        const size_t value_length = static_cast <size_t> (get_uint32 (ptr));
+        ptr += 4;
+        bytes_left -= 4;
+
+        if (bytes_left < value_length)
+            break;
+        const unsigned char * const value = ptr;
+        ptr += value_length;
+        bytes_left -= value_length;
+
+        if (name == "Socket-Type") {
+            //  TODO: Implement socket type checking
+        }
+        else
+        if (name == "Identity" && options.recv_identity)
+            set_peer_identity (value, value_length);
+    }
+
+    if (bytes_left > 0) {
+        errno = EPROTO;
+        return -1;
+    }
+
+    int rc = msg_->close ();
+    errno_assert (rc == 0);
+    rc = msg_->init ();
+    errno_assert (rc == 0);
+
+    ready_command_received = true;
+
+    return 0;
+}
+
+bool zmq::null_mechanism_t::is_handshake_complete () const
+{
+    return ready_command_received && ready_command_sent;
+}