1 /*
2 * Copyright (c) 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 package sun.security.ssl;
26
27 import java.io.IOException;
28 import java.math.BigInteger;
29 import java.security.*;
30 import java.security.interfaces.XECPublicKey;
31 import java.security.spec.*;
32 import sun.security.ssl.NamedGroup.NamedGroupSpec;
33 import sun.security.util.*;
34
35 /**
36 * Specifics for XEC/XDH Keys/Exchanges
37 */
38 final class XDHKeyExchange {
39
40 static final SSLKeyAgreementGenerator xdheKAGenerator
41 = new XDHEKAGenerator();
42
43 static final class XDHECredentials implements NamedGroupCredentials {
44
45 final XECPublicKey popPublicKey;
46 final NamedGroup namedGroup;
47
48 XDHECredentials(XECPublicKey popPublicKey, NamedGroup namedGroup) {
49 this.popPublicKey = popPublicKey;
50 this.namedGroup = namedGroup;
51 }
52
53 @Override
54 public PublicKey getPublicKey() {
55 return popPublicKey;
56 }
57
58 @Override
59 public NamedGroup getNamedGroup() {
60 return namedGroup;
61 }
62
63 /**
64 * Parse the encoded Point into the XDHECredentials using the
65 * namedGroup.
66 */
67 static XDHECredentials valueOf(NamedGroup namedGroup,
68 byte[] encodedPoint) throws IOException,
69 GeneralSecurityException {
70
71 if (namedGroup.spec != NamedGroupSpec.NAMED_GROUP_XDH) {
72 throw new RuntimeException(
73 "Credentials decoding: Not XDH named group");
74 }
75
76 if (encodedPoint == null || encodedPoint.length == 0) {
77 return null;
78 }
79
80 byte[] uBytes = encodedPoint.clone();
81 Utilities.reverseBytes(uBytes);
82 BigInteger u = new BigInteger(1, uBytes);
83
84 XECPublicKeySpec xecPublicKeySpec = new XECPublicKeySpec(
85 new NamedParameterSpec(namedGroup.name), u);
86 KeyFactory factory = JsseJce.getKeyFactory(namedGroup.algorithm);
87 XECPublicKey publicKey = (XECPublicKey) factory.generatePublic(
88 xecPublicKeySpec);
89
90 return new XDHECredentials(publicKey, namedGroup);
91 }
92 }
93
94 static final class XDHEPossession implements NamedGroupPossession {
95
96 final PrivateKey privateKey;
97 final XECPublicKey publicKey;
98 final NamedGroup namedGroup;
99
100 XDHEPossession(NamedGroup namedGroup, SecureRandom random) {
101 try {
102 KeyPairGenerator kpg
103 = JsseJce.getKeyPairGenerator(namedGroup.algorithm);
104 kpg.initialize(namedGroup.keAlgParamSpec, random);
105 KeyPair kp = kpg.generateKeyPair();
106 privateKey = kp.getPrivate();
107 publicKey = (XECPublicKey) kp.getPublic();
108 } catch (GeneralSecurityException e) {
109 throw new RuntimeException(
110 "Could not generate XDH keypair", e);
111 }
112
113 this.namedGroup = namedGroup;
114 }
115
116 @Override
117 public byte[] encode() {
118
119 byte[] uBytes = ECUtil.trimZeroes(publicKey.getU().toByteArray());
120
121 int expLength;
122 switch (namedGroup) {
123 case X25519:
124 expLength = 32;
125 break;
126 case X448:
127 expLength = 56;
128 break;
129 default:
130 throw new RuntimeException("Invalid XDH group");
131 }
132
133 if (uBytes.length > expLength) {
134 throw new RuntimeException("Encoded XDH key too large");
135 }
136
137 if (uBytes.length != expLength) {
138 byte[] tmp = new byte[expLength];
139 System.arraycopy(uBytes, 0, tmp,
140 expLength - uBytes.length, uBytes.length);
141 uBytes = tmp;
142 }
143
144 Utilities.reverseBytes(uBytes);
145 return (uBytes);
146 }
147
148 @Override
149 public PublicKey getPublicKey() {
150 return publicKey;
151 }
152
153 @Override
154 public NamedGroup getNamedGroup() {
155 return namedGroup;
156 }
157
158 @Override
159 public PrivateKey getPrivateKey() {
160 return privateKey;
161 }
162 }
163
164 private static final class XDHEKAGenerator
165 implements SSLKeyAgreementGenerator {
166
167 // Prevent instantiation of this class.
168 private XDHEKAGenerator() {
169 // blank
170 }
171
172 @Override
173 public SSLKeyDerivation createKeyDerivation(
174 HandshakeContext context) throws IOException {
175 XDHEPossession xdhePossession = null;
176 XDHECredentials xdheCredentials = null;
177 for (SSLPossession poss : context.handshakePossessions) {
178 if (!(poss instanceof XDHEPossession)) {
179 continue;
180 }
181
182 NamedGroup ng = ((XDHEPossession) poss).namedGroup;
183 for (SSLCredentials cred : context.handshakeCredentials) {
184 if (!(cred instanceof XDHECredentials)) {
185 continue;
186 }
187 if (ng.equals(((XDHECredentials) cred).namedGroup)) {
188 xdheCredentials = (XDHECredentials) cred;
189 break;
190 }
191 }
192
193 if (xdheCredentials != null) {
194 xdhePossession = (XDHEPossession) poss;
195 break;
196 }
197 }
198
199 if (xdhePossession == null || xdheCredentials == null) {
200 context.conContext.fatal(Alert.HANDSHAKE_FAILURE,
201 "No sufficient XDHE key agreement "
202 + "parameters negotiated");
203 }
204
205 return new KAKeyDerivation("XDH", context,
206 xdhePossession.privateKey, xdheCredentials.popPublicKey);
207 }
208 }
209 }