1 /*

     2  * Copyright (c) 2015, 2018, 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.incubator.http.internal.websocket;

    27 

    28 import jdk.incubator.http.HttpClient;

    29 import jdk.incubator.http.HttpClient.Version;

    30 import jdk.incubator.http.HttpHeaders;

    31 import jdk.incubator.http.HttpRequest;

    32 import jdk.incubator.http.HttpResponse;

    33 import jdk.incubator.http.HttpResponse.BodyHandler;

    34 import jdk.incubator.http.WebSocketHandshakeException;

    35 import jdk.incubator.http.internal.common.MinimalFuture;

    36 import jdk.incubator.http.internal.common.Pair;

    37 import jdk.incubator.http.internal.common.Utils;

    38 

    39 import java.io.IOException;

    40 import java.net.InetSocketAddress;

    41 import java.net.Proxy;

    42 import java.net.ProxySelector;

    43 import java.net.URI;

    44 import java.net.URISyntaxException;

    45 import java.net.URLPermission;

    46 import java.nio.charset.StandardCharsets;

    47 import java.security.AccessController;

    48 import java.security.MessageDigest;

    49 import java.security.NoSuchAlgorithmException;

    50 import java.security.PrivilegedAction;

    51 import java.security.SecureRandom;

    52 import java.time.Duration;

    53 import java.util.Base64;

    54 import java.util.Collection;

    55 import java.util.Collections;

    56 import java.util.LinkedHashSet;

    57 import java.util.List;

    58 import java.util.Optional;

    59 import java.util.Set;

    60 import java.util.TreeSet;

    61 import java.util.concurrent.CompletableFuture;

    62 import java.util.stream.Collectors;

    63 import java.util.stream.Stream;

    64 

    65 import static java.lang.String.format;

    66 import static jdk.incubator.http.internal.common.Utils.isValidName;

    67 import static jdk.incubator.http.internal.common.Utils.permissionForProxy;

    68 import static jdk.incubator.http.internal.common.Utils.stringOf;

    69 

    70 public class OpeningHandshake {

    71 

    72     private static final String HEADER_CONNECTION = "Connection";

    73     private static final String HEADER_UPGRADE    = "Upgrade";

    74     private static final String HEADER_ACCEPT     = "Sec-WebSocket-Accept";

    75     private static final String HEADER_EXTENSIONS = "Sec-WebSocket-Extensions";

    76     private static final String HEADER_KEY        = "Sec-WebSocket-Key";

    77     private static final String HEADER_PROTOCOL   = "Sec-WebSocket-Protocol";

    78     private static final String HEADER_VERSION    = "Sec-WebSocket-Version";

    79     private static final String VERSION           = "13";  // WebSocket's lucky number

    80 

    81     private static final Set<String> ILLEGAL_HEADERS;

    82 

    83     static {

    84         ILLEGAL_HEADERS = new TreeSet<>(String.CASE_INSENSITIVE_ORDER);

    85         ILLEGAL_HEADERS.addAll(List.of(HEADER_ACCEPT,

    86                                        HEADER_EXTENSIONS,

    87                                        HEADER_KEY,

    88                                        HEADER_PROTOCOL,

    89                                        HEADER_VERSION));

    90     }

    91 

    92     private static final SecureRandom random = new SecureRandom();

    93 

    94     private final MessageDigest sha1;

    95     private final HttpClient client;

    96 

    97     {

    98         try {

    99             sha1 = MessageDigest.getInstance("SHA-1");

   100         } catch (NoSuchAlgorithmException e) {

   101             // Shouldn't happen: SHA-1 must be available in every Java platform

   102             // implementation

   103             throw new InternalError("Minimum requirements", e);

   104         }

   105     }

   106 

   107     private final HttpRequest request;

   108     private final Collection<String> subprotocols;

   109     private final String nonce;

   110 

   111     public OpeningHandshake(BuilderImpl b) {

   112         checkURI(b.getUri());

   113         Proxy proxy = proxyFor(b.getProxySelector(), b.getUri());

   114         checkPermissions(b, proxy);

   115         this.client = b.getClient();

   116         URI httpURI = createRequestURI(b.getUri());

   117         HttpRequest.Builder requestBuilder = HttpRequest.newBuilder(httpURI);

   118         Duration connectTimeout = b.getConnectTimeout();

   119         if (connectTimeout != null) {

   120             requestBuilder.timeout(connectTimeout);

   121         }

   122         for (Pair<String, String> p : b.getHeaders()) {

   123             if (ILLEGAL_HEADERS.contains(p.first)) {

   124                 throw illegal("Illegal header: " + p.first);

   125             }

   126             requestBuilder.header(p.first, p.second);

   127         }

   128         this.subprotocols = createRequestSubprotocols(b.getSubprotocols());

   129         if (!this.subprotocols.isEmpty()) {

   130             String p = this.subprotocols.stream().collect(Collectors.joining(", "));

   131             requestBuilder.header(HEADER_PROTOCOL, p);

   132         }

   133         requestBuilder.header(HEADER_VERSION, VERSION);

   134         this.nonce = createNonce();

   135         requestBuilder.header(HEADER_KEY, this.nonce);

   136         // Setting request version to HTTP/1.1 forcibly, since it's not possible

   137         // to upgrade from HTTP/2 to WebSocket (as of August 2016):

   138         //

   139         //     https://tools.ietf.org/html/draft-hirano-httpbis-websocket-over-http2-00

   140         this.request = requestBuilder.version(Version.HTTP_1_1).GET().build();

   141         WebSocketRequest r = (WebSocketRequest) this.request;

   142         r.isWebSocket(true);

   143         r.setSystemHeader(HEADER_UPGRADE, "websocket");

   144         r.setSystemHeader(HEADER_CONNECTION, "Upgrade");

   145         r.setProxy(proxy);

   146     }

   147 

   148     private static Collection<String> createRequestSubprotocols(

   149             Collection<String> subprotocols)

   150     {

   151         LinkedHashSet<String> sp = new LinkedHashSet<>(subprotocols.size(), 1);

   152         for (String s : subprotocols) {

   153             if (s.trim().isEmpty() || !isValidName(s)) {

   154                 throw illegal("Bad subprotocol syntax: " + s);

   155             }

   156             if (!sp.add(s)) {

   157                 throw illegal("Duplicating subprotocol: " + s);

   158             }

   159         }

   160         return Collections.unmodifiableCollection(sp);

   161     }

   162 

   163     /*

   164      * Checks the given URI for being a WebSocket URI and translates it into a

   165      * target HTTP URI for the Opening Handshake.

   166      *

   167      * https://tools.ietf.org/html/rfc6455#section-3

   168      */

   169     static URI createRequestURI(URI uri) {

   170         String s = uri.getScheme();

   171         assert "ws".equalsIgnoreCase(s) || "wss".equalsIgnoreCase(s);

   172         String scheme = "ws".equalsIgnoreCase(s) ? "http" : "https";

   173         try {

   174             return new URI(scheme,

   175                            uri.getUserInfo(),

   176                            uri.getHost(),

   177                            uri.getPort(),

   178                            uri.getPath(),

   179                            uri.getQuery(),

   180                            null); // No fragment

   181         } catch (URISyntaxException e) {

   182             // Shouldn't happen: URI invariant

   183             throw new InternalError(e);

   184         }

   185     }

   186 

   187     public CompletableFuture<Result> send() {

   188         PrivilegedAction<CompletableFuture<Result>> pa = () ->

   189                 client.sendAsync(this.request, BodyHandler.discard())

   190                       .thenCompose(this::resultFrom);

   191         return AccessController.doPrivileged(pa);

   192     }

   193 

   194     /*

   195      * The result of the opening handshake.

   196      */

   197     static final class Result {

   198 

   199         final String subprotocol;

   200         final TransportFactory transport;

   201 

   202         private Result(String subprotocol, TransportFactory transport) {

   203             this.subprotocol = subprotocol;

   204             this.transport = transport;

   205         }

   206     }

   207 

   208     private CompletableFuture<Result> resultFrom(HttpResponse<?> response) {

   209         // Do we need a special treatment for SSLHandshakeException?

   210         // Namely, invoking

   211         //

   212         //     Listener.onClose(StatusCodes.TLS_HANDSHAKE_FAILURE, "")

   213         //

   214         // See https://tools.ietf.org/html/rfc6455#section-7.4.1

   215         Result result = null;

   216         Exception exception = null;

   217         try {

   218             result = handleResponse(response);

   219         } catch (IOException e) {

   220             exception = e;

   221         } catch (Exception e) {

   222             exception = new WebSocketHandshakeException(response).initCause(e);

   223         }

   224         if (exception == null) {

   225             return MinimalFuture.completedFuture(result);

   226         }

   227         try {

   228             ((RawChannel.Provider) response).rawChannel().close();

   229         } catch (IOException e) {

   230             exception.addSuppressed(e);

   231         }

   232         return MinimalFuture.failedFuture(exception);

   233     }

   234 

   235     private Result handleResponse(HttpResponse<?> response) throws IOException {

   236         // By this point all redirects, authentications, etc. (if any) MUST have

   237         // been done by the HttpClient used by the WebSocket; so only 101 is

   238         // expected

   239         int c = response.statusCode();

   240         if (c != 101) {

   241             throw checkFailed("Unexpected HTTP response status code " + c);

   242         }

   243         HttpHeaders headers = response.headers();

   244         String upgrade = requireSingle(headers, HEADER_UPGRADE);

   245         if (!upgrade.equalsIgnoreCase("websocket")) {

   246             throw checkFailed("Bad response field: " + HEADER_UPGRADE);

   247         }

   248         String connection = requireSingle(headers, HEADER_CONNECTION);

   249         if (!connection.equalsIgnoreCase("Upgrade")) {

   250             throw checkFailed("Bad response field: " + HEADER_CONNECTION);

   251         }

   252         Optional<String> version = requireAtMostOne(headers, HEADER_VERSION);

   253         if (version.isPresent() && !version.get().equals(VERSION)) {

   254             throw checkFailed("Bad response field: " + HEADER_VERSION);

   255         }

   256         requireAbsent(headers, HEADER_EXTENSIONS);

   257         String x = this.nonce + "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";

   258         this.sha1.update(x.getBytes(StandardCharsets.ISO_8859_1));

   259         String expected = Base64.getEncoder().encodeToString(this.sha1.digest());

   260         String actual = requireSingle(headers, HEADER_ACCEPT);

   261         if (!actual.trim().equals(expected)) {

   262             throw checkFailed("Bad " + HEADER_ACCEPT);

   263         }

   264         String subprotocol = checkAndReturnSubprotocol(headers);

   265         RawChannel channel = ((RawChannel.Provider) response).rawChannel();

   266         return new Result(subprotocol, new TransportFactoryImpl(channel));

   267     }

   268 

   269     private String checkAndReturnSubprotocol(HttpHeaders responseHeaders)

   270             throws CheckFailedException

   271     {

   272         Optional<String> opt = responseHeaders.firstValue(HEADER_PROTOCOL);

   273         if (!opt.isPresent()) {

   274             // If there is no such header in the response, then the server

   275             // doesn't want to use any subprotocol

   276             return "";

   277         }

   278         String s = requireSingle(responseHeaders, HEADER_PROTOCOL);

   279         // An empty string as a subprotocol's name is not allowed by the spec

   280         // and the check below will detect such responses too

   281         if (this.subprotocols.contains(s)) {

   282             return s;

   283         } else {

   284             throw checkFailed("Unexpected subprotocol: " + s);

   285         }

   286     }

   287 

   288     private static void requireAbsent(HttpHeaders responseHeaders,

   289                                       String headerName)

   290     {

   291         List<String> values = responseHeaders.allValues(headerName);

   292         if (!values.isEmpty()) {

   293             throw checkFailed(format("Response field '%s' present: %s",

   294                                      headerName,

   295                                      stringOf(values)));

   296         }

   297     }

   298 

   299     private static Optional<String> requireAtMostOne(HttpHeaders responseHeaders,

   300                                                      String headerName)

   301     {

   302         List<String> values = responseHeaders.allValues(headerName);

   303         if (values.size() > 1) {

   304             throw checkFailed(format("Response field '%s' multivalued: %s",

   305                                      headerName,

   306                                      stringOf(values)));

   307         }

   308         return values.stream().findFirst();

   309     }

   310 

   311     private static String requireSingle(HttpHeaders responseHeaders,

   312                                         String headerName)

   313     {

   314         List<String> values = responseHeaders.allValues(headerName);

   315         if (values.isEmpty()) {

   316             throw checkFailed("Response field missing: " + headerName);

   317         } else if (values.size() > 1) {

   318             throw checkFailed(format("Response field '%s' multivalued: %s",

   319                                      headerName,

   320                                      stringOf(values)));

   321         }

   322         return values.get(0);

   323     }

   324 

   325     private static String createNonce() {

   326         byte[] bytes = new byte[16];

   327         OpeningHandshake.random.nextBytes(bytes);

   328         return Base64.getEncoder().encodeToString(bytes);

   329     }

   330 

   331     private static CheckFailedException checkFailed(String message) {

   332         throw new CheckFailedException(message);

   333     }

   334 

   335     private static URI checkURI(URI uri) {

   336         String scheme = uri.getScheme();

   337         if (!("ws".equalsIgnoreCase(scheme) || "wss".equalsIgnoreCase(scheme)))

   338             throw illegal("invalid URI scheme: " + scheme);

   339         if (uri.getHost() == null)

   340             throw illegal("URI must contain a host: " + uri);

   341         if (uri.getFragment() != null)

   342             throw illegal("URI must not contain a fragment: " + uri);

   343         return uri;

   344     }

   345 

   346     private static IllegalArgumentException illegal(String message) {

   347         return new IllegalArgumentException(message);

   348     }

   349 

   350     /**

   351      * Returns the proxy for the given URI when sent through the given client,

   352      * or {@code null} if none is required or applicable.

   353      */

   354     private static Proxy proxyFor(Optional<ProxySelector> selector, URI uri) {

   355         if (!selector.isPresent()) {

   356             return null;

   357         }

   358         URI requestURI = createRequestURI(uri); // Based on the HTTP scheme

   359         List<Proxy> pl = selector.get().select(requestURI);

   360         if (pl.isEmpty()) {

   361             return null;

   362         }

   363         Proxy proxy = pl.get(0);

   364         if (proxy.type() != Proxy.Type.HTTP) {

   365             return null;

   366         }

   367         return proxy;

   368     }

   369 

   370     /**

   371      * Performs the necessary security permissions checks to connect ( possibly

   372      * through a proxy ) to the builders WebSocket URI.

   373      *

   374      * @throws SecurityException if the security manager denies access

   375      */

   376     static void checkPermissions(BuilderImpl b, Proxy proxy) {

   377         SecurityManager sm = System.getSecurityManager();

   378         if (sm == null) {

   379             return;

   380         }

   381         Stream<String> headers = b.getHeaders().stream().map(p -> p.first).distinct();

   382         URLPermission perm1 = Utils.permissionForServer(b.getUri(), "", headers);

   383         sm.checkPermission(perm1);

   384         if (proxy == null) {

   385             return;

   386         }

   387         URLPermission perm2 = permissionForProxy((InetSocketAddress) proxy.address());

   388         if (perm2 != null) {

   389             sm.checkPermission(perm2);

   390         }

   391     }

   392 }