PC World Komputer 2010 April/PCWorld0410.iso/pluginy Firefox/58189/58189.xpi/modules/Whitelist.jsm

Text File | 2010-01-07 | 6KB | 222 lines

/*
 * This class implements a whitelist for domains. This means that certain
 * domains can be freed from policy decisions.

 * ATTENTION: initialization is done by loadList(), but can not be done at
 * startup time. Apparantly, Firefox does not find the preferences and thinks
 * they are not set. Only after loading the browser, the prefs are available.
 */

var EXPORTED_SYMBOLS = [ ];
Components.utils.import("resource://csfiremodules/CsFireCommon.jsm");

CsFire.nsJSON = Components.classes["@mozilla.org/dom/json;1"].createInstance(Components.interfaces.nsIJSON);

CsFire.Whitelist = new function() {
    this.list = [];
    this.loaded = false;
};


/*
 * Checks whether there are whitelist entries matching the current request and
 * returns either the whitelist decision (accept) or null if no match was found
 */
CsFire.Whitelist.decide = function(data) {
    var src = data.referrer_host;
    var dst = data.dst_host;

    var result = false;
    var list = this.getList(); //Loads the list if this has not been done yet
    for(var i in list) {
        var item = list[i];
        if(item) {
            if(item.enabled && this.isMatch(dst, item.destination) && this.isMatch(src, item.origin)) {
                return { "action": CsFire.Policy.ACCEPT,
                         "whitelist": true };
            }
        }
    }
    return null;
}

/*
 * Checks whether a certain URI matches agains a certain domain
 */
CsFire.Whitelist.isMatch = function(stringUri, domain) {
    var result = true;
    var splitUri;
    stringUri == null ? splitUri = ["null"] : splitUri = stringUri.split(".");
    var splitDomain = domain.split(".");
    var indexUri = splitUri.length - 1;
    var indexDomain = splitDomain.length - 1;

    while(indexUri >= 0 && indexDomain >= 0 && result) {
        if(splitDomain[indexDomain] != "*" && (splitDomain[indexDomain] != splitUri[indexUri])) {
            result = false;
        }
        indexUri--;
        indexDomain--;
    }

    //Check if the match has been completed
    //(e.g. domain=test.www.google.be and uri=www.google.be is not a match!)
    if(result && indexDomain >= 0) {
        result = false;
    }

    return result;
}

/*
 * Adds an entry to the whitelist using the provided origin and destination. If
 * one of these is invalid, null is returned. Otherwise, the added rule is
 * returned as an object.
 */
CsFire.Whitelist.addEntry = function(origin, destination) {
    var result = null;
    try {
        if(this.isValidDomain(origin) && this.isValidDomain(destination)) {
            var theList = this.getList();
            var exists = false;
            for(var i = 0; i < theList.length && !exists; i++) {
                var item = theList[i];
                if(item && item.origin == origin && item.destination == destination) {
                    exists = true;
                }
            }

            if(!exists) {
                var item = {"origin": origin,
                            "destination": destination,
                            "enabled": true};
                // Add item to end of list
                this.list.push(item);
                // Make the change persistent
                this.storeList();

                result = item;
            }
        }
        else {
            result = { "error": "Invalid input" };
            if(!this.isValidDomain(origin)) {
                result.errororigin = true;
            }
            if(!this.isValidDomain(destination)) {
                result.errordestination = true;
            }
        }
    }
    catch(e) {
        CsFire.Logger.error("Failed to add domain to whitelist: " + e);
        result = { "error": "Error adding domain" };
    }
    return result;
};

/*
 * Changes the "enabled" status of an entry
 */
CsFire.Whitelist.updateEntryStatus = function(entry) {
    var result = null;
    var done = false;
    for(var i = 0; i < this.list.length && !done; i++) {
        var item = this.list[i];
        if(item && item.origin == entry.origin && item.destination == entry.destination) {
            CsFire.Logger.debug("Changing state of item to " + (!item.enabled));
            item.enabled = !(item.enabled);
            done = true;
        }
    }
    this.storeList();
};

/*
 * Removes an entry from the whitelist
 */
CsFire.Whitelist.removeEntry = function(origin, destination) {
    var result = true;
    try {
        /*
         * Simply set the index to null. The item will be removed next time the
         * browser is loaded and the list is retrieved from the prefs.
         */
        var done = false;
        for(var i = 0; i < this.list.length && !done; i++) {
            var item = this.list[i];
            if(item && item.origin == origin && item.destination == destination) {
                delete this.list[i];
                done = true;
            }
        }

        // Make the change persistent
        this.storeList();
    }
    catch(e) {
        CsFire.Logger.error("Failed to remove domain from whitelist: " + e);
        result = false;
    }
    return result;
};

/*
 * Returns a list of entries in the whitelist. Loads the list if this has not
 * been done yet.
 */
CsFire.Whitelist.getList = function() {
    // Load the list if this has not been done before
    this.loadList();
    return this.list;
}

/*
 * Checks whether the provided domain is a valid domain name
 */
CsFire.Whitelist.isValidDomain = function(domain) {
    var result = true;

    var splitted = domain.split(".");
    for(var i = 0; i < splitted.length && result; i++) {
        var item = splitted[i];
        if(item == null || item == "" || (item != "*" && !item.match(/^[a-zA-Z0-9\-_]+$/))) {
            result = false;
        }
    }

    return result;
};


/*
 * Loads the list from the preferences into memory
 */
CsFire.Whitelist.loadList = function() {
    // If loaded before, abort
    if(this.loaded) return;
    this.loaded = true;

    var s = CsFire.PreferenceUtils.getStringPreference("extensions.csfire.whitelist", null);
    if(s) {

        var value = CsFire.nsJSON.decode(s);
        for(var i in value) {
            var entry = value[i];
            if(entry != null) {
                this.list.push(entry);
            }
        }
    }
};

/*
 * Stores the list from memory to preferences.
 */
CsFire.Whitelist.storeList = function() {
    var storeList = this.getList();
    var value = CsFire.nsJSON.encode(storeList);
    CsFire.PreferenceUtils.setStringPreference("extensions.csfire.whitelist", value);
};