.Xauth-based authorisation

lib/x11/auth.js

@@ -1,11 +1,91 @@
 // TODO: http://en.wikipedia.org/wiki/X_Window_authorization
 
-module.exports = function( cb )
+var fs = require('fs');
+var Buffer = require('buffer').Buffer;
+// add 'unpack' method for buffer
+require('./unpackbuffer').addUnpack(Buffer);
+
+function parseXauth( buf )
 {
-    // empty yet
+    var offset = 0;
-    var authType = '';
+    var auth = [];
-    var authData = '';
+
-    cb( authType, authData );
+    while (offset < buf.length)
+    {
+        var cookie = {};        
+        var typeToName = {
+            256: 'Local',
+          65535: 'Wild',
+            254: 'Netname',
+            253: 'Krb5Principal', 
+            252: 'LocalHost',
+              0: 'Internet', 
+              1: 'DECnet', 
+              2: 'Chaos',
+ 	     5: 'ServerInterpreted', 
+              6: 'InternetV6'
+        };
+        cookie.type = buf.unpack('n')[0];
+        offset += 2;
+        console.log(cookie.type);
+        // TODO: rewrite following using loop (16bits length + string data)
+        var addressLen = buf.unpack('n', offset)[0];        
+        offset += 2;
+        console.log(addressLen);
+        cookie.address = buf.unpackString(addressLen, offset);
+        offset += addressLen;
+        var displayNumLen = buf.unpack('n', offset)[0];    
+        console.log(displayNumLen);
+        offset += 2;
+        cookie.display = buf.unpackString(displayNumLen, offset);
+        offset += displayNumLen;
+        var authNameLen = buf.unpack('n', offset)[0];
+        offset += 2;
+        console.log(authNameLen);
+        cookie.authName = buf.unpackString(authNameLen, offset);
+        offset += authNameLen;
+        var authDataLen = buf.unpack('n', offset)[0];
+        offset += 2;
+        console.log(authDataLen);
+        cookie.authData = buf.unpackString(authDataLen, offset);
+        offset += authDataLen;
+        auth.push(cookie);        
+    }
+    return auth;
 }
 
-// TODO: rewrite to allow negotiation of auth type with server
+module.exports = function( display, host, cb )
+{
+    var XAuthorityFile = process.env.XAUTHORITY;
+    if (!XAuthorityFile)
+    {
+        if ( process.platform.match(/win/) ) {
+            // http://www.straightrunning.com/XmingNotes/trouble.php
+            //
+            // The Xming magic cookie program, xauth (user-based), uses an 
+            // Xauthority file (not the traditional .Xauthority file) in 
+            // the %HOME% directory. To use xauth from Command Processor 
+            // e.g. on Windows machine 192.168.0.2 with user colin...
+            XAuthorityFile = process.env.USERPROFILE + '\\Xauthority';
+        } else {
+            XAuthorityFile = process.env.HOME + '/.Xauthority';
+        }
+        fs.readFile(XAuthorityFile, function (err, data) {
+
+            if (err) throw err;
+
+            var auth = parseXauth(data);
+            for (cookieNum in auth)
+            {
+                var cookie = auth[cookieNum];
+                if (cookie.display == display && cookie.address == host)
+                {
+                    cb( cookie.authName, cookie.authData );
+                    return;
+                }
+            }
+            throw 'No auth cookie matching display=' + display + ' and  host=' + host;
+
+        });
+    }   
+}

lib/x11/handshake.js

@@ -180,9 +180,9 @@ bl.unpack('C', function(res) {
 
 }
 
-function writeClientHello(stream)
+function writeClientHello(stream, displayNum, authHost)
 {
-    getAuthString( function( authType, authData ) {
+    getAuthString( displayNum, authHost, function( authType, authData ) {
         authType = xutil.padded_string( authType );
         authData = xutil.padded_string( authData );
         var byte_order = 'l'.charCodeAt(0); // TODO: byteorder!!!

lib/x11/unpackbuffer.js

@@ -30,6 +30,11 @@ module.exports.addUnpack = function(Buffer)
                 var b2 = this[offset++];
                 data.push(b2*256+b1);
                 break;
+            case 'n':
+                var b1 = this[offset++];
+                var b2 = this[offset++];
+                data.push(b1*256+b2);
+                break;
             case 'L':
                 var b1 = this[offset++];
                 var b2 = this[offset++];

lib/x11/xcore.js

@@ -13,6 +13,8 @@ var Buffer = require('buffer').Buffer;
 // add 'unpack' method for buffer
 require('./unpackbuffer').addUnpack(Buffer);
 
+var os = require('os');
+
 var xerrors = require('./xerrors');
 var coreRequests = require('./corereqs');
 var stdatoms = require('./stdatoms');
@@ -281,7 +283,7 @@ XClient.prototype.startHandshake = function()
 {
     var client = this;
 
-    handshake.writeClientHello(this.pack_stream);
+    handshake.writeClientHello(this.pack_stream, this.displayNum, this.authHost);
     handshake.readServerHello(this.pack_stream, function(display) 
     {
         // TODO: readServerHello can set erro state in display
@@ -300,20 +302,37 @@ var platformDefaultTransport = {
    // TODO: check process.platform on SmartMachine solaris box
 }
 
-module.exports.createClient = function(initCb)
+module.exports.createClient = function(initCb, display)
 {
-     // TODO: parse $DISPLAY
+    if (!display)
+       display = process.env.DISPLAY;
+    if (!display)
+        display = ':0';
+
+    var displayMatch = display.match(/^(?:[^:]*?\/)?(.*):(\d+)(?:.(\d+))?$/);
+    var host = displayMatch[1];
+    if (!host)
+        host = '127.0.0.1';
+    var displayNum = displayMatch[2];
+    if (!displayNum)
+        displayNum = 0;
+    var screenNum = displayMatch[3];
+    if (!screenNum)
+        screenNum = 0;
     
-     // open stream
+    // open stream
-     var stream;
+    var stream;
-     var defaultTransportName = platformDefaultTransport[process.platform];
+    var defaultTransportName = platformDefaultTransport[process.platform];
-     // use tcp if stated explicitly or if not defined at all
+    // use tcp if stated explicitly or if not defined at all
-     if (!defaultTransportName || defaultTransportName == 'tcp')
+    if (!defaultTransportName || defaultTransportName == 'tcp' || host != '127.0.0.1')
-         stream = net.createConnection(6000);
+        stream = net.createConnection(6000 + displayNum, host);
-     if (defaultTransportName == 'unix')
+    if (defaultTransportName == 'unix' && host == '127.0.0.1')
-         stream = net.createConnection('/tmp/.X11-unix/X0');
+        stream = net.createConnection('/tmp/.X11-unix/X' + displayNum);
 
     var client = new XClient(stream);
+    client.displayNum = displayNum;
+    client.screenNum = screenNum;
+    client.authHost = os.hostname();
     if (initCb)
     {
         client.on('connect', function(display) {