GUACAMOLE-1298: Enforce default limit on request size.

guacamole/src/main/java/org/apache/guacamole/rest/APIException.java

@@ -33,18 +33,15 @@ import org.apache.guacamole.GuacamoleException;
 public class APIException extends WebApplicationException {
 
     /**
-     * Construct a new APIException based on the given GuacamoleException and
-     * HTTP status. The details of the GuacamoleException relevant to the REST
-     * API will be exposed via an APIError.
-     *
-     * @param status
-     *     The HTTP status which corresponds to the GuacamoleException.
+     * Construct a new APIException based on the given GuacamoleException. The
+     * details of the GuacamoleException relevant to the REST API will be
+     * exposed via an APIError.
      *
      * @param exception
      *     The GuacamoleException that occurred.
      */
-    public APIException(Response.Status status, GuacamoleException exception) {
-        super(Response.status(status)
+    public APIException(GuacamoleException exception) {
+        super(Response.status(exception.getHttpStatusCode())
                 .type(MediaType.APPLICATION_JSON)
                 .entity(new APIError(exception))
                 .build());

guacamole/src/main/java/org/apache/guacamole/rest/LimitedRequestInputStream.java

@@ -0,0 +1,152 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.guacamole.rest;
+
+import java.io.IOException;
+import java.io.InputStream;
+import org.apache.guacamole.GuacamoleClientOverrunException;
+
+/**
+ * InputStream implementation which limits the body of REST API requests to
+ * a particular maximum size. If an attempt is made to read from a REST API
+ * request which exceeds this limit, the read attempt will be aborted by
+ * throwing an APIException.
+ */
+public class LimitedRequestInputStream extends InputStream {
+
+    /**
+     * The InputStream being limited.
+     */
+    private final InputStream stream;
+
+    /**
+     * The maximum number of bytes to allow to be read or skipped.
+     */
+    private final long maxLength;
+
+    /**
+     * The total number of bytes that have been read or skipped from the stream
+     * thus far.
+     */
+    private long bytesRead = 0;
+
+    /**
+     * Wraps the given InputStream, ensuring that the overall number of bytes
+     * read or skipped does not exceed the given maximum length.
+     *
+     * @param stream
+     *     The InputStream to limit.
+     *
+     * @param maxLength
+     *     The maximum number of bytes to allow to be read or skipped.
+     */
+    public LimitedRequestInputStream(InputStream stream, long maxLength) {
+        this.stream = stream;
+        this.maxLength = maxLength;
+    }
+
+    /**
+     * Immediately verifies that the stream length limit has not been exceeded.
+     * If the length limit has been exceeded, an APIException is thrown
+     * indicating that the request body is too large.
+     *
+     * @throws APIException
+     *     If the length limit has been exceeded.
+     */
+    private synchronized void recheckLength() throws APIException {
+        if (bytesRead > maxLength)
+            throw new APIException(new GuacamoleClientOverrunException("Request body/entity too large."));
+    }
+
+    /**
+     * Updates the current number of bytes read based on the return value of a
+     * read-like operation such as read() or skip(). If the maximum stream
+     * length is exceeded as a result of the read, an APIException indicating
+     * this is thrown.
+     *
+     * NOTE: To avoid unnecessary read operations, recheckLength() should be
+     * manually called before performing any read operation. This function will
+     * perform the same checks, but can inherently only do so AFTER the read
+     * operation has occurred.
+     *
+     * @param change
+     *     The number of bytes that have been read or skipped, or -1 if the
+     *     read-like operation has failed (and no bytes have been read).
+     *
+     * @return
+     *     The provided number of bytes read/skipped.
+     *
+     * @throws APIException
+     *     If the read-like operation that occurred has caused the stream
+     *     length to exceed its maximum.
+     */
+    private synchronized long limitedRead(long change) throws APIException {
+
+        if (change != -1) {
+            bytesRead += change;
+            recheckLength();
+        }
+
+        return change;
+
+    }
+
+    @Override
+    public void close() throws IOException {
+        stream.close();
+    }
+
+    @Override
+    public int available() throws IOException {
+        return stream.available();
+    }
+
+    @Override
+    public long skip(long l) throws IOException {
+        recheckLength();
+        return limitedRead(stream.skip(l));
+    }
+
+    @Override
+    public int read(byte[] bytes, int i, int i1) throws IOException {
+        recheckLength();
+        return (int) limitedRead(stream.read(bytes, i, i1));
+    }
+
+    @Override
+    public int read(byte[] bytes) throws IOException {
+        recheckLength();
+        return (int) limitedRead(stream.read(bytes));
+    }
+
+    @Override
+    public int read() throws IOException {
+
+        recheckLength();
+
+        int value = stream.read();
+        if (value != -1)
+            limitedRead(1);
+
+        return value;
+
+    }
+
+}

guacamole/src/main/java/org/apache/guacamole/rest/RESTExceptionMapper.java

@@ -22,6 +22,7 @@ package org.apache.guacamole.rest;
 import com.google.inject.Inject;
 import com.google.inject.Singleton;
 import javax.servlet.http.HttpServletRequest;
+import javax.ws.rs.WebApplicationException;
 import javax.ws.rs.core.Context;
 import javax.ws.rs.core.MediaType;
 import javax.ws.rs.core.Response;
@@ -82,6 +83,10 @@ public class RESTExceptionMapper implements ExceptionMapper<Throwable> {
     
     @Override
     public Response toResponse(Throwable t) {
+
+        // Pass WebApplicationException responses through untouched
+        if (t instanceof WebApplicationException)
+            return ((WebApplicationException) t).getResponse();
         
         // Ensure any associated session is invalidated if unauthorized 
         if (t instanceof GuacamoleUnauthorizedException) {

guacamole/src/main/java/org/apache/guacamole/rest/RESTServiceModule.java

@@ -24,10 +24,11 @@ import org.apache.guacamole.rest.session.UserContextResourceFactory;
 import org.apache.guacamole.rest.session.SessionRESTService;
 import com.google.inject.Scopes;
 import com.google.inject.assistedinject.FactoryModuleBuilder;
-import com.google.inject.matcher.Matchers;
 import com.google.inject.servlet.ServletModule;
+import com.sun.jersey.api.core.ResourceConfig;
 import com.sun.jersey.guice.spi.container.servlet.GuiceContainer;
-import org.aopalliance.intercept.MethodInterceptor;
+import java.util.HashMap;
+import java.util.Map;
 import org.apache.guacamole.rest.activeconnection.ActiveConnectionModule;
 import org.codehaus.jackson.jaxrs.JacksonJsonProvider;
 import org.apache.guacamole.rest.auth.TokenRESTService;
@@ -75,6 +76,8 @@ public class RESTServiceModule extends ServletModule {
     @Override
     protected void configureServlets() {
 
+        Map<String, String> containerParams = new HashMap<>();
+
         // Bind session map
         bind(TokenSessionMap.class).toInstance(tokenSessionMap);
 
@@ -87,6 +90,10 @@ public class RESTServiceModule extends ServletModule {
         // Automatically translate GuacamoleExceptions for REST methods
         bind(RESTExceptionMapper.class);
 
+        // Restrict API requests by entity size
+        containerParams.put(ResourceConfig.PROPERTY_CONTAINER_REQUEST_FILTERS, RequestSizeFilter.class.getName());
+        bind(RequestSizeFilter.class).in(Scopes.SINGLETON);
+
         // Set up the API endpoints
         bind(ExtensionRESTService.class);
         bind(LanguageRESTService.class);
@@ -111,7 +118,7 @@ public class RESTServiceModule extends ServletModule {
         // Set up the servlet and JSON mappings
         bind(GuiceContainer.class);
         bind(JacksonJsonProvider.class).in(Scopes.SINGLETON);
-        serve("/api/*").with(GuiceContainer.class);
+        serve("/api/*").with(GuiceContainer.class, containerParams);
 
         // Serve Webjar JavaScript dependencies
         bind(WebjarsServlet.class).in(Scopes.SINGLETON);

guacamole/src/main/java/org/apache/guacamole/rest/RequestSizeFilter.java

@@ -0,0 +1,89 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+package org.apache.guacamole.rest;
+
+import com.google.inject.Inject;
+import com.sun.jersey.spi.container.ContainerRequest;
+import com.sun.jersey.spi.container.ContainerRequestFilter;
+import com.sun.jersey.spi.resource.Singleton;
+import java.io.InputStream;
+import javax.ws.rs.ext.Provider;
+import org.apache.guacamole.GuacamoleException;
+import org.apache.guacamole.environment.Environment;
+import org.apache.guacamole.properties.LongGuacamoleProperty;
+
+/**
+ * Filter which restricts REST API requests to a particular maximum size.
+ */
+@Singleton
+@Provider
+public class RequestSizeFilter implements ContainerRequestFilter {
+
+    /**
+     * The default maximum number of bytes to accept within the entity body of
+     * any particular REST request.
+     */
+    private final long DEFAULT_MAX_REQUEST_SIZE = 2097152;
+
+    /**
+     * The maximum number of bytes to accept within the entity body of any
+     * particular REST request. If not specified, requests will be limited to
+     * 2 MB by default. Specifying 0 disables request size limitations.
+     */
+    private final LongGuacamoleProperty API_MAX_REQUEST_SIZE = new LongGuacamoleProperty() {
+
+        @Override
+        public String getName() { return "api-max-request-size"; }
+
+    };
+
+    /**
+     * The Guacamole server environment.
+     */
+    @Inject
+    private Environment environment;
+
+    @Override
+    public ContainerRequest filter(ContainerRequest request) {
+
+        // Retrieve configured request size limits
+        final long maxRequestSize;
+        try {
+            maxRequestSize = environment.getProperty(API_MAX_REQUEST_SIZE, DEFAULT_MAX_REQUEST_SIZE);
+        }
+        catch (GuacamoleException e) {
+            throw new APIException(e);
+        }
+
+        // Ignore request size if limit is disabled
+        if (maxRequestSize == 0)
+            return request;
+
+        // Restrict maximum size of requests which have an input stream
+        // available to be limited
+        InputStream stream = request.getEntityInputStream();
+        if (stream != null)
+            request.setEntityInputStream(new LimitedRequestInputStream(stream, maxRequestSize));
+
+        return request;
+
+    }
+
+}

guacamole/src/main/java/org/apache/guacamole/rest/history/APISortPredicate.java

@@ -109,10 +109,7 @@ public class APISortPredicate {
 
         // Bail out if sort property is not valid
         catch (IllegalArgumentException e) {
-            throw new APIException(
-                Response.Status.BAD_REQUEST,
-                new GuacamoleClientException(String.format("Invalid sort property: \"%s\"", value))
-            );
+            throw new APIException(new GuacamoleClientException(String.format("Invalid sort property: \"%s\"", value)));
         }
 
     }