1 /*
2 * Copyright (c) 2015, 2019, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation. Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26 package jdk.internal.net.http.websocket;
27
28 import java.net.http.HttpClient;
29 import java.net.http.HttpClient.Version;
30 import java.net.http.HttpHeaders;
31 import java.net.http.HttpRequest;
32 import java.net.http.HttpResponse;
33 import java.net.http.HttpResponse.BodyHandlers;
34 import java.net.http.WebSocketHandshakeException;
35
36 import jdk.internal.net.http.HttpRequestBuilderImpl;
37 import jdk.internal.net.http.HttpRequestImpl;
38 import jdk.internal.net.http.common.MinimalFuture;
39 import jdk.internal.net.http.common.Pair;
40 import jdk.internal.net.http.common.Utils;
41
42 import java.io.IOException;
43 import java.net.InetSocketAddress;
44 import java.net.Proxy;
45 import java.net.ProxySelector;
46 import java.net.URI;
47 import java.net.URISyntaxException;
48 import java.net.URLPermission;
49 import java.nio.charset.StandardCharsets;
50 import java.security.AccessController;
51 import java.security.MessageDigest;
52 import java.security.NoSuchAlgorithmException;
53 import java.security.PrivilegedAction;
54 import java.security.SecureRandom;
55 import java.time.Duration;
56 import java.util.Base64;
57 import java.util.Collection;
58 import java.util.Collections;
59 import java.util.LinkedHashSet;
60 import java.util.List;
61 import java.util.Optional;
62 import java.util.Set;
63 import java.util.TreeSet;
64 import java.util.concurrent.CompletableFuture;
65 import java.util.stream.Collectors;
66 import java.util.stream.Stream;
67
68 import static java.lang.String.format;
69 import static jdk.internal.net.http.common.Utils.isValidName;
70 import static jdk.internal.net.http.common.Utils.permissionForProxy;
71 import static jdk.internal.net.http.common.Utils.stringOf;
72
73 public class OpeningHandshake {
74
75 private static final String HEADER_CONNECTION = "Connection";
76 private static final String HEADER_UPGRADE = "Upgrade";
77 private static final String HEADER_ACCEPT = "Sec-WebSocket-Accept";
78 private static final String HEADER_EXTENSIONS = "Sec-WebSocket-Extensions";
79 private static final String HEADER_KEY = "Sec-WebSocket-Key";
80 private static final String HEADER_PROTOCOL = "Sec-WebSocket-Protocol";
81 private static final String HEADER_VERSION = "Sec-WebSocket-Version";
82 private static final String VERSION = "13"; // WebSocket's lucky number
83
84 private static final Set<String> ILLEGAL_HEADERS;
85
86 static {
87 ILLEGAL_HEADERS = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);
88 ILLEGAL_HEADERS.addAll(List.of(HEADER_ACCEPT,
89 HEADER_EXTENSIONS,
90 HEADER_KEY,
91 HEADER_PROTOCOL,
92 HEADER_VERSION));
93 }
94
95 private static final SecureRandom random = new SecureRandom();
96
97 private final MessageDigest sha1;
98 private final HttpClient client;
99
100 {
101 try {
102 sha1 = MessageDigest.getInstance("SHA-1");
103 } catch (NoSuchAlgorithmException e) {
104 // Shouldn't happen: SHA-1 must be available in every Java platform
105 // implementation
106 throw new InternalError("Minimum requirements", e);
107 }
108 }
109
110 private final HttpRequestImpl request;
111 private final Collection<String> subprotocols;
112 private final String nonce;
113
114 public OpeningHandshake(BuilderImpl b) {
115 checkURI(b.getUri());
116 Proxy proxy = proxyFor(b.getProxySelector(), b.getUri());
117 checkPermissions(b, proxy);
118 this.client = b.getClient();
119 URI httpURI = createRequestURI(b.getUri());
120 HttpRequestBuilderImpl requestBuilder = new HttpRequestBuilderImpl(httpURI);
121 Duration connectTimeout = b.getConnectTimeout();
122 if (connectTimeout != null) {
123 requestBuilder.timeout(connectTimeout);
124 }
125 for (Pair<String, String> p : b.getHeaders()) {
126 if (ILLEGAL_HEADERS.contains(p.first)) {
127 throw illegal("Illegal header: " + p.first);
128 }
129 requestBuilder.header(p.first, p.second);
130 }
131 this.subprotocols = createRequestSubprotocols(b.getSubprotocols());
132 if (!this.subprotocols.isEmpty()) {
133 String p = String.join(", ", this.subprotocols);
134 requestBuilder.header(HEADER_PROTOCOL, p);
135 }
136 requestBuilder.header(HEADER_VERSION, VERSION);
137 this.nonce = createNonce();
138 requestBuilder.header(HEADER_KEY, this.nonce);
139 // Setting request version to HTTP/1.1 forcibly, since it's not possible
140 // to upgrade from HTTP/2 to WebSocket (as of August 2016):
141 //
142 // https://tools.ietf.org/html/draft-hirano-httpbis-websocket-over-http2-00
143 requestBuilder.version(Version.HTTP_1_1).GET();
144 request = requestBuilder.buildForWebSocket();
145 request.isWebSocket(true);
146 Utils.setWebSocketUpgradeHeaders(request);
147 request.setProxy(proxy);
148 }
149
150 private static Collection<String> createRequestSubprotocols(
151 Collection<String> subprotocols)
152 {
153 LinkedHashSet<String> sp = new LinkedHashSet<>(subprotocols.size(), 1);
154 for (String s : subprotocols) {
155 if (s.trim().isEmpty() || !isValidName(s)) {
156 throw illegal("Bad subprotocol syntax: " + s);
157 }
158 if (!sp.add(s)) {
159 throw illegal("Duplicating subprotocol: " + s);
160 }
161 }
162 return Collections.unmodifiableCollection(sp);
163 }
164
165 /*
166 * Checks the given URI for being a WebSocket URI and translates it into a
167 * target HTTP URI for the Opening Handshake.
168 *
169 * https://tools.ietf.org/html/rfc6455#section-3
170 */
171 static URI createRequestURI(URI uri) {
172 String s = uri.getScheme();
173 assert "ws".equalsIgnoreCase(s) || "wss".equalsIgnoreCase(s);
174 String scheme = "ws".equalsIgnoreCase(s) ? "http" : "https";
175 try {
176 return new URI(scheme,
177 uri.getUserInfo(),
178 uri.getHost(),
179 uri.getPort(),
180 uri.getPath(),
181 uri.getQuery(),
182 null); // No fragment
183 } catch (URISyntaxException e) {
184 // Shouldn't happen: URI invariant
185 throw new InternalError(e);
186 }
187 }
188
189 public CompletableFuture<Result> send() {
190 PrivilegedAction<CompletableFuture<Result>> pa = () ->
191 client.sendAsync(this.request, BodyHandlers.discarding())
192 .thenCompose(this::resultFrom);
193 return AccessController.doPrivileged(pa);
194 }
195
196 /*
197 * The result of the opening handshake.
198 */
199 static final class Result {
200
201 final String subprotocol;
202 final TransportFactory transport;
203
204 private Result(String subprotocol, TransportFactory transport) {
205 this.subprotocol = subprotocol;
206 this.transport = transport;
207 }
208 }
209
210 private CompletableFuture<Result> resultFrom(HttpResponse<?> response) {
211 // Do we need a special treatment for SSLHandshakeException?
212 // Namely, invoking
213 //
214 // Listener.onClose(StatusCodes.TLS_HANDSHAKE_FAILURE, "")
215 //
216 // See https://tools.ietf.org/html/rfc6455#section-7.4.1
217 Result result = null;
218 Exception exception = null;
219 try {
220 result = handleResponse(response);
221 } catch (IOException e) {
222 exception = e;
223 } catch (Exception e) {
224 exception = new WebSocketHandshakeException(response).initCause(e);
225 }
226 if (exception == null) {
227 return MinimalFuture.completedFuture(result);
228 }
229 try {
230 ((RawChannel.Provider) response).rawChannel().close();
231 } catch (IOException e) {
232 exception.addSuppressed(e);
233 }
234 return MinimalFuture.failedFuture(exception);
235 }
236
237 private Result handleResponse(HttpResponse<?> response) throws IOException {
238 // By this point all redirects, authentications, etc. (if any) MUST have
239 // been done by the HttpClient used by the WebSocket; so only 101 is
240 // expected
241 int c = response.statusCode();
242 if (c != 101) {
243 throw checkFailed("Unexpected HTTP response status code " + c);
244 }
245 HttpHeaders headers = response.headers();
246 String upgrade = requireSingle(headers, HEADER_UPGRADE);
247 if (!upgrade.equalsIgnoreCase("websocket")) {
248 throw checkFailed("Bad response field: " + HEADER_UPGRADE);
249 }
250 String connection = requireSingle(headers, HEADER_CONNECTION);
251 if (!connection.equalsIgnoreCase("Upgrade")) {
252 throw checkFailed("Bad response field: " + HEADER_CONNECTION);
253 }
254 Optional<String> version = requireAtMostOne(headers, HEADER_VERSION);
255 if (version.isPresent() && !version.get().equals(VERSION)) {
256 throw checkFailed("Bad response field: " + HEADER_VERSION);
257 }
258 requireAbsent(headers, HEADER_EXTENSIONS);
259 String x = this.nonce + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
260 this.sha1.update(x.getBytes(StandardCharsets.ISO_8859_1));
261 String expected = Base64.getEncoder().encodeToString(this.sha1.digest());
262 String actual = requireSingle(headers, HEADER_ACCEPT);
263 if (!actual.trim().equals(expected)) {
264 throw checkFailed("Bad " + HEADER_ACCEPT);
265 }
266 String subprotocol = checkAndReturnSubprotocol(headers);
267 RawChannel channel = ((RawChannel.Provider) response).rawChannel();
268 return new Result(subprotocol, new TransportFactoryImpl(channel));
269 }
270
271 private String checkAndReturnSubprotocol(HttpHeaders responseHeaders)
272 throws CheckFailedException
273 {
274 Optional<String> opt = responseHeaders.firstValue(HEADER_PROTOCOL);
275 if (!opt.isPresent()) {
276 // If there is no such header in the response, then the server
277 // doesn't want to use any subprotocol
278 return "";
279 }
280 String s = requireSingle(responseHeaders, HEADER_PROTOCOL);
281 // An empty string as a subprotocol's name is not allowed by the spec
282 // and the check below will detect such responses too
283 if (this.subprotocols.contains(s)) {
284 return s;
285 } else {
286 throw checkFailed("Unexpected subprotocol: " + s);
287 }
288 }
289
290 private static void requireAbsent(HttpHeaders responseHeaders,
291 String headerName)
292 {
293 List<String> values = responseHeaders.allValues(headerName);
294 if (!values.isEmpty()) {
295 throw checkFailed(format("Response field '%s' present: %s",
296 headerName,
297 stringOf(values)));
298 }
299 }
300
301 private static Optional<String> requireAtMostOne(HttpHeaders responseHeaders,
302 String headerName)
303 {
304 List<String> values = responseHeaders.allValues(headerName);
305 if (values.size() > 1) {
306 throw checkFailed(format("Response field '%s' multivalued: %s",
307 headerName,
308 stringOf(values)));
309 }
310 return values.stream().findFirst();
311 }
312
313 private static String requireSingle(HttpHeaders responseHeaders,
314 String headerName)
315 {
316 List<String> values = responseHeaders.allValues(headerName);
317 if (values.isEmpty()) {
318 throw checkFailed("Response field missing: " + headerName);
319 } else if (values.size() > 1) {
320 throw checkFailed(format("Response field '%s' multivalued: %s",
321 headerName,
322 stringOf(values)));
323 }
324 return values.get(0);
325 }
326
327 private static String createNonce() {
328 byte[] bytes = new byte[16];
329 OpeningHandshake.random.nextBytes(bytes);
330 return Base64.getEncoder().encodeToString(bytes);
331 }
332
333 private static CheckFailedException checkFailed(String message) {
334 throw new CheckFailedException(message);
335 }
336
337 private static URI checkURI(URI uri) {
338 String scheme = uri.getScheme();
339 if (!("ws".equalsIgnoreCase(scheme) || "wss".equalsIgnoreCase(scheme)))
340 throw illegal("invalid URI scheme: " + scheme);
341 if (uri.getHost() == null)
342 throw illegal("URI must contain a host: " + uri);
343 if (uri.getFragment() != null)
344 throw illegal("URI must not contain a fragment: " + uri);
345 return uri;
346 }
347
348 private static IllegalArgumentException illegal(String message) {
349 return new IllegalArgumentException(message);
350 }
351
352 /**
353 * Returns the proxy for the given URI when sent through the given client,
354 * or {@code null} if none is required or applicable.
355 */
356 private static Proxy proxyFor(Optional<ProxySelector> selector, URI uri) {
357 if (!selector.isPresent()) {
358 return null;
359 }
360 URI requestURI = createRequestURI(uri); // Based on the HTTP scheme
361 List<Proxy> pl = selector.get().select(requestURI);
362 if (pl.isEmpty()) {
363 return null;
364 }
365 Proxy proxy = pl.get(0);
366 if (proxy.type() != Proxy.Type.HTTP) {
367 return null;
368 }
369 return proxy;
370 }
371
372 /**
373 * Performs the necessary security permissions checks to connect ( possibly
374 * through a proxy ) to the builders WebSocket URI.
375 *
376 * @throws SecurityException if the security manager denies access
377 */
378 static void checkPermissions(BuilderImpl b, Proxy proxy) {
379 SecurityManager sm = System.getSecurityManager();
380 if (sm == null) {
381 return;
382 }
383 Stream<String> headers = b.getHeaders().stream().map(p -> p.first).distinct();
384 URLPermission perm1 = Utils.permissionForServer(b.getUri(), "", headers);
385 sm.checkPermission(perm1);
386 if (proxy == null) {
387 return;
388 }
389 URLPermission perm2 = permissionForProxy((InetSocketAddress) proxy.address());
390 if (perm2 != null) {
391 sm.checkPermission(perm2);
392 }
393 }
394 }