1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27 package org.apache.hc.client5.http.impl;
28
29 import java.util.Iterator;
30
31 import org.apache.hc.core5.annotation.Internal;
32 import org.apache.hc.core5.http.HttpHeaders;
33 import org.apache.hc.core5.http.HttpMessage;
34 import org.apache.hc.core5.http.ParseException;
35 import org.apache.hc.core5.http.ProtocolException;
36 import org.apache.hc.core5.http.ProtocolVersion;
37 import org.apache.hc.core5.http.message.MessageSupport;
38 import org.apache.hc.core5.http.ssl.TLS;
39
40 /**
41 * Protocol switch handler.
42 *
43 * @since 5.4
44 */
45 @Internal
46 public final class ProtocolSwitchStrategy {
47
48 enum ProtocolSwitch { FAILURE, TLS }
49
50 public ProtocolVersion switchProtocol(final HttpMessage response) throws ProtocolException {
51 final Iterator<String> it = MessageSupport.iterateTokens(response, HttpHeaders.UPGRADE);
52
53 ProtocolVersion tlsUpgrade = null;
54 while (it.hasNext()) {
55 final String token = it.next();
56 if (token.startsWith("TLS")) {
57 // TODO: Improve handling of HTTP protocol token once HttpVersion has a #parse method
58 try {
59 tlsUpgrade = token.length() == 3 ? TLS.V_1_2.getVersion() : TLS.parse(token.replace("TLS/", "TLSv"));
60 } catch (final ParseException ex) {
61 throw new ProtocolException("Invalid protocol: " + token);
62 }
63 } else if (token.equals("HTTP/1.1")) {
64 // TODO: Improve handling of HTTP protocol token once HttpVersion has a #parse method
65 } else {
66 throw new ProtocolException("Unsupported protocol: " + token);
67 }
68 }
69 if (tlsUpgrade == null) {
70 throw new ProtocolException("Invalid protocol switch response");
71 }
72 return tlsUpgrade;
73 }
74
75 }