Abstract security mechanism

src/Makefile.am

@@ -39,9 +39,11 @@ libzmq_la_SOURCES = \
     lb.hpp \
     likely.hpp \
     mailbox.hpp \
+    mechanism.hpp  \
     msg.hpp \
     mtrie.hpp \
     mutex.hpp \
+    null_mechanism.hpp \
     object.hpp \
     options.hpp \
     own.hpp \
@@ -100,8 +102,10 @@ libzmq_la_SOURCES = \
     kqueue.cpp \
     lb.cpp \
     mailbox.cpp \
+    mechanism.cpp \
     msg.cpp \
     mtrie.cpp \
+    null_mechanism.cpp \
     object.cpp \
     options.cpp \
     own.cpp \

src/mechanism.cpp

@@ -0,0 +1,73 @@
+/*
+    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 <string.h>
+
+#include "mechanism.hpp"
+#include "options.hpp"
+#include "msg.hpp"
+#include "err.hpp"
+#include "wire.hpp"
+
+zmq::mechanism_t::mechanism_t (const options_t &options_) :
+    options (options_)
+{
+}
+
+zmq::mechanism_t::~mechanism_t ()
+{
+}
+
+void zmq::mechanism_t::set_peer_identity (const void *id_ptr, size_t id_size)
+{
+    identity = blob_t (static_cast <const unsigned char*> (id_ptr), id_size);
+}
+
+void zmq::mechanism_t::peer_identity (msg_t *msg_)
+{
+    const int rc = msg_->init_size (identity.size ());
+    errno_assert (rc == 0);
+    memcpy (msg_->data (), identity.data (), identity.size ());
+    msg_->set_flags (msg_t::identity);
+}
+
+const char *zmq::mechanism_t::socket_type_string (int socket_type) const
+{
+    static const char *names [] = {"PAIR", "PUB", "SUB", "REQ", "REP",
+                                   "DEALER", "ROUTER", "PULL", "PUSH",
+                                   "XPUB", "XSUB"};
+    zmq_assert (socket_type >= 0 && socket_type <= 10);
+    return names [socket_type];
+}
+
+size_t zmq::mechanism_t::add_property (unsigned char *ptr, const char *name,
+    const void *value, size_t value_len) const
+{
+    const size_t name_len = strlen (name);
+    zmq_assert (name_len <= 255);
+    *ptr++ = static_cast <unsigned char> (name_len);
+    memcpy (ptr, name, name_len);
+    ptr += name_len;
+    zmq_assert (value_len <= (2^31) - 1);
+    put_uint32 (ptr, static_cast <uint32_t> (value_len));
+    ptr += 4;
+    memcpy (ptr, value, value_len);
+
+    return 1 + name_len + 4 + value_len;
+}

src/mechanism.hpp

@@ -0,0 +1,73 @@
+/*
+    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/>.
+*/
+
+#ifndef __ZMQ_MECHANISM_HPP_INCLUDED__
+#define __ZMQ_MECHANISM_HPP_INCLUDED__
+
+#include <stdint.h>
+
+#include "options.hpp"
+#include "blob.hpp"
+
+namespace zmq
+{
+
+    //  Abstract class representing security mechanism.
+    //  Different mechanism extedns this class.
+
+    class msg_t;
+
+    class mechanism_t
+    {
+    public:
+
+        mechanism_t (const options_t &options_);
+
+        virtual ~mechanism_t ();
+
+        //  Prepare next handshake message that is to be sent to the peer.
+        virtual int next_handshake_message (msg_t *msg_) = 0;
+
+        //  Process the handshake message received from the peer.
+        virtual int process_handshake_message (msg_t *msg_) = 0;
+
+        //  True iff the handshake stage is complete?
+        virtual bool is_handshake_complete () const = 0;
+
+        void set_peer_identity (const void *id_ptr, size_t id_size);
+
+        void peer_identity (msg_t *msg_);
+
+    protected:
+
+        const char *socket_type_string (int socket_type) const;
+
+        size_t add_property (unsigned char *ptr, const char *name,
+            const void *value, size_t value_len) const;
+
+        options_t options;
+
+    private:
+
+        blob_t identity;
+    };
+
+}
+
+#endif

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;
+}

src/null_mechanism.hpp

@@ -0,0 +1,51 @@
+/*
+    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/>.
+*/
+
+#ifndef __ZMQ_NULL_MECHANISM_HPP_INCLUDED__
+#define __ZMQ_NULL_MECHANISM_HPP_INCLUDED__
+
+#include "mechanism.hpp"
+#include "options.hpp"
+
+namespace zmq
+{
+
+    class msg_t;
+
+    class null_mechanism_t : public mechanism_t
+    {
+    public:
+
+        null_mechanism_t (const options_t &options_);
+        virtual ~null_mechanism_t ();
+
+        // mechanism implementation
+        virtual int next_handshake_message (msg_t *msg_);
+        virtual int process_handshake_message (msg_t *msg_);
+        virtual bool is_handshake_complete () const;
+
+    private:
+
+        bool ready_command_sent;
+        bool ready_command_received;
+    };
+
+}
+
+#endif