1 /*
2 * Copyright (c) 2006, 2012, 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 sun.security.ssl;
27
28 import java.io.IOException;
29 import java.io.PrintStream;
30 import java.util.*;
31 import javax.net.ssl.*;
32
33 /**
34 * This file contains all the classes relevant to TLS Extensions for the
35 * ClientHello and ServerHello messages. The extension mechanism and
36 * several extensions are defined in RFC 3546. Additional extensions are
37 * defined in the ECC RFC 4492.
38 *
39 * Currently, only the two ECC extensions are fully supported.
40 *
41 * The classes contained in this file are:
42 * . HelloExtensions: a List of extensions as used in the client hello
43 * and server hello messages.
44 * . ExtensionType: an enum style class for the extension type
45 * . HelloExtension: abstract base class for all extensions. All subclasses
46 * must be immutable.
47 *
48 * . UnknownExtension: used to represent all parsed extensions that we do not
49 * explicitly support.
50 * . ServerNameExtension: the server_name extension.
51 * . SignatureAlgorithmsExtension: the signature_algorithms extension.
52 * . SupportedEllipticCurvesExtension: the ECC supported curves extension.
53 * . SupportedEllipticPointFormatsExtension: the ECC supported point formats
54 * (compressed/uncompressed) extension.
55 *
56 * @since 1.6
57 * @author Andreas Sterbenz
58 */
59 final class HelloExtensions {
60
61 private List<HelloExtension> extensions;
62 private int encodedLength;
63
64 HelloExtensions() {
65 extensions = Collections.emptyList();
66 }
67
68 HelloExtensions(HandshakeInStream s) throws IOException {
69 int len = s.getInt16();
70 extensions = new ArrayList<HelloExtension>();
71 encodedLength = len + 2;
72 while (len > 0) {
73 int type = s.getInt16();
74 int extlen = s.getInt16();
75 ExtensionType extType = ExtensionType.get(type);
76 HelloExtension extension;
77 if (extType == ExtensionType.EXT_SERVER_NAME) {
78 extension = new ServerNameExtension(s, extlen);
79 } else if (extType == ExtensionType.EXT_SIGNATURE_ALGORITHMS) {
80 extension = new SignatureAlgorithmsExtension(s, extlen);
81 } else if (extType == ExtensionType.EXT_ELLIPTIC_CURVES) {
82 extension = new SupportedEllipticCurvesExtension(s, extlen);
83 } else if (extType == ExtensionType.EXT_EC_POINT_FORMATS) {
84 extension =
85 new SupportedEllipticPointFormatsExtension(s, extlen);
86 } else if (extType == ExtensionType.EXT_RENEGOTIATION_INFO) {
87 extension = new RenegotiationInfoExtension(s, extlen);
88 } else if (extType == ExtensionType.EXT_MAX_FRAGMENT_LENGTH) {
89 extension = new MaxFragmentLengthExtension(s, extlen);
90 } else {
91 extension = new UnknownExtension(s, extlen, extType);
92 }
93 extensions.add(extension);
94 len -= extlen + 4;
95 }
96 if (len != 0) {
97 throw new SSLProtocolException(
98 "Error parsing extensions: extra data");
99 }
100 }
101
102 // Return the List of extensions. Must not be modified by the caller.
103 List<HelloExtension> list() {
104 return extensions;
105 }
106
107 void add(HelloExtension ext) {
108 if (extensions.isEmpty()) {
109 extensions = new ArrayList<HelloExtension>();
110 }
111 extensions.add(ext);
112 encodedLength = -1;
113 }
114
115 HelloExtension get(ExtensionType type) {
116 for (HelloExtension ext : extensions) {
117 if (ext.type == type) {
118 return ext;
119 }
120 }
121 return null;
122 }
123
124 int length() {
125 if (encodedLength >= 0) {
126 return encodedLength;
127 }
128 if (extensions.isEmpty()) {
129 encodedLength = 0;
130 } else {
131 encodedLength = 2;
132 for (HelloExtension ext : extensions) {
133 encodedLength += ext.length();
134 }
135 }
136 return encodedLength;
137 }
138
139 void send(HandshakeOutStream s) throws IOException {
140 int length = length();
141 if (length == 0) {
142 return;
143 }
144 s.putInt16(length - 2);
145 for (HelloExtension ext : extensions) {
146 ext.send(s);
147 }
148 }
149
150 void print(PrintStream s) throws IOException {
151 for (HelloExtension ext : extensions) {
152 s.println(ext.toString());
153 }
154 }
155 }