Merge pull request #274 from glyptodon/restrict-lang

GUAC-1345: Restrict available languages if explicitly configured

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/extension/ExtensionModule.java

@@ -100,7 +100,7 @@ public class ExtensionModule extends ServletModule {
     /**
      * Service for adding and retrieving language resources.
      */
-    private final LanguageResourceService languageResourceService = new LanguageResourceService();
+    private final LanguageResourceService languageResourceService;
     
     /**
      * Returns the classloader that should be used as the parent classloader
@@ -139,6 +139,7 @@ public class ExtensionModule extends ServletModule {
      */
     public ExtensionModule(Environment environment) {
         this.environment = environment;
+        this.languageResourceService = new LanguageResourceService(environment);
     }
 
     /**

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/extension/LanguageResourceService.java

@@ -36,6 +36,9 @@ import org.codehaus.jackson.JsonNode;
 import org.codehaus.jackson.map.ObjectMapper;
 import org.codehaus.jackson.node.JsonNodeFactory;
 import org.codehaus.jackson.node.ObjectNode;
+import org.glyptodon.guacamole.GuacamoleException;
+import org.glyptodon.guacamole.environment.Environment;
+import org.glyptodon.guacamole.net.basic.properties.BasicGuacamoleProperties;
 import org.glyptodon.guacamole.net.basic.resource.ByteArrayResource;
 import org.glyptodon.guacamole.net.basic.resource.Resource;
 import org.glyptodon.guacamole.net.basic.resource.WebApplicationResource;
@@ -76,6 +79,13 @@ public class LanguageResourceService {
      */
     private static final Pattern LANGUAGE_KEY_PATTERN = Pattern.compile(".*/([a-z]+(_[A-Z]+)?)\\.json");
 
+    /**
+     * The set of all language keys which are explicitly listed as allowed
+     * within guacamole.properties, or null if all defined languages should be
+     * allowed.
+     */
+    private final Set<String> allowedLanguages;
+
     /**
      * Map of all language resources by language key. Language keys are
      * language and country code pairs, separated by an underscore, like
@@ -86,6 +96,35 @@ public class LanguageResourceService {
      */
     private final Map<String, Resource> resources = new HashMap<String, Resource>();
 
+    /**
+     * Creates a new service for tracking and parsing available translations
+     * which reads its configuration from the given environment.
+     *
+     * @param environment
+     *     The environment from which the configuration properties of this
+     *     service should be read.
+     */
+    public LanguageResourceService(Environment environment) {
+
+        Set<String> parsedAllowedLanguages;
+
+        // Parse list of available languages from properties
+        try {
+            parsedAllowedLanguages = environment.getProperty(BasicGuacamoleProperties.ALLOWED_LANGUAGES);
+            logger.debug("Available languages will be restricted to: {}", parsedAllowedLanguages);
+        }
+
+        // Warn of failure to parse
+        catch (GuacamoleException e) {
+            parsedAllowedLanguages = null;
+            logger.error("Unable to parse list of allowed languages: {}", e.getMessage());
+            logger.debug("Error parsing list of allowed languages.", e);
+        }
+
+        this.allowedLanguages = parsedAllowedLanguages;
+
+    }
+
     /**
      * Derives a language key from the filename within the given path, if
      * possible. If the filename is not a valid language key, null is returned.
@@ -184,6 +223,31 @@ public class LanguageResourceService {
 
     }
 
+    /**
+     * Returns whether a language having the given key should be allowed to be
+     * loaded. If language availability restrictions are imposed through
+     * guacamole.properties, this may return false in some cases. By default,
+     * this function will always return true. Note that just because a language
+     * key is allowed to be loaded does not imply that the language key is
+     * valid.
+     *
+     * @param languageKey
+     *     The language key of the language to test.
+     *
+     * @return
+     *     true if the given language key should be allowed to be loaded, false
+     *     otherwise.
+     */
+    private boolean isLanguageAllowed(String languageKey) {
+
+        // If no list is provided, all languages are implicitly available
+        if (allowedLanguages == null)
+            return true;
+
+        return allowedLanguages.contains(languageKey);
+
+    }
+
     /**
      * Adds or overlays the given language resource, which need not exist in
      * the ServletContext. If a language resource is already defined for the
@@ -202,6 +266,12 @@ public class LanguageResourceService {
      */
     public void addLanguageResource(String key, Resource resource) {
 
+        // Skip loading of language if not allowed
+        if (!isLanguageAllowed(key)) {
+            logger.debug("OMITTING language: \"{}\"", key);
+            return;
+        }
+
         // Merge language resources if already defined
         Resource existing = resources.get(key);
         if (existing != null) {

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/properties/BasicGuacamoleProperties.java

@@ -24,6 +24,7 @@ package org.glyptodon.guacamole.net.basic.properties;
 
 import org.glyptodon.guacamole.properties.FileGuacamoleProperty;
 import org.glyptodon.guacamole.properties.IntegerGuacamoleProperty;
+import org.glyptodon.guacamole.properties.StringGuacamoleProperty;
 
 /**
  * Properties used by the default Guacamole web application.
@@ -73,4 +74,17 @@ public class BasicGuacamoleProperties {
 
     };
 
+    /**
+     * Comma-separated list of all allowed languages, where each language is
+     * represented by a language key, such as "en" or "en_US". If specified,
+     * only languages within this list will be listed as available by the REST
+     * service.
+     */
+    public static final StringSetProperty ALLOWED_LANGUAGES = new StringSetProperty() {
+
+        @Override
+        public String getName() { return "allowed-languages"; }
+
+    };
+
 }

guacamole/src/main/java/org/glyptodon/guacamole/net/basic/properties/StringSetProperty.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (C) 2015 Glyptodon LLC
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package org.glyptodon.guacamole.net.basic.properties;
+
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.regex.Pattern;
+import org.glyptodon.guacamole.GuacamoleException;
+import org.glyptodon.guacamole.properties.GuacamoleProperty;
+
+/**
+ * A GuacamoleProperty whose value is a Set of unique Strings. The string value
+ * parsed to produce this set is a comma-delimited list. Duplicate values are
+ * ignored, as is any whitespace following delimiters. To maintain
+ * compatibility with the behavior of Java properties in general, only
+ * whitespace at the beginning of each value is ignored; trailing whitespace
+ * becomes part of the value.
+ *
+ * @author Michael Jumper
+ */
+public abstract class StringSetProperty implements GuacamoleProperty<Set<String>> {
+
+    /**
+     * A pattern which matches against the delimiters between values. This is
+     * currently simply a comma and any following whitespace. Parts of the
+     * input string which match this pattern will not be included in the parsed
+     * result.
+     */
+    private static final Pattern DELIMITER_PATTERN = Pattern.compile(",\\s*");
+
+    @Override
+    public Set<String> parseValue(String values) throws GuacamoleException {
+
+        // If no property provided, return null.
+        if (values == null)
+            return null;
+
+        // Split string into a set of individual values
+        List<String> valueList = Arrays.asList(DELIMITER_PATTERN.split(values));
+        return new HashSet<String>(valueList);
+
+    }
+
+}

guacamole/src/main/webapp/app/locale/services/translationLoader.js

@@ -29,9 +29,10 @@
 angular.module('locale').factory('translationLoader', ['$injector', function translationLoader($injector) {
 
     // Required services
-    var $http        = $injector.get('$http');
+    var $http           = $injector.get('$http');
-    var $q           = $injector.get('$q');
+    var $q              = $injector.get('$q');
-    var cacheService = $injector.get('cacheService');
+    var cacheService    = $injector.get('cacheService');
+    var languageService = $injector.get('languageService');
 
     /**
      * Satisfies a translation request for the given key by searching for the
@@ -62,22 +63,48 @@ angular.module('locale').factory('translationLoader', ['$injector', function tra
             return;
         }
 
-        // Attempt to retrieve language
+        /**
-        $http({
+         * Continues trying possible translation files until no possibilities
-            cache   : cacheService.languages,
+         * exist.
-            method  : 'GET',
+         *
-            url     : 'translations/' + encodeURIComponent(currentKey) + '.json'
+         * @private
-        })
+         */
-
+        var tryNextTranslation = function tryNextTranslation() {
-        // Resolve promise if translation retrieved successfully
-        .success(function translationFileRetrieved(translation) {
-            deferred.resolve(translation);
-        })
-
-        // Retry with remaining languages if translation file could not be retrieved
-        .error(function translationFileUnretrievable() {
             satisfyTranslation(deferred, requestedKey, remainingKeys);
-        });
+        };
+
+        // Retrieve list of supported languages
+        languageService.getLanguages()
+
+        // Attempt to retrieve translation if language is supported
+        .success(function retrievedLanguages(languages) {
+
+            // Skip retrieval if language is not supported
+            if (!(currentKey in languages)) {
+                tryNextTranslation();
+                return;
+            }
+
+            // Attempt to retrieve language
+            $http({
+                cache   : cacheService.languages,
+                method  : 'GET',
+                url     : 'translations/' + encodeURIComponent(currentKey) + '.json'
+            })
+
+            // Resolve promise if translation retrieved successfully
+            .success(function translationFileRetrieved(translation) {
+                deferred.resolve(translation);
+            })
+
+            // Retry with remaining languages if translation file could not be
+            // retrieved
+            .error(tryNextTranslation);
+
+        })
+
+        // Retry with remaining languages if translation does not exist
+        .error(tryNextTranslation);
 
     };