1 /*
2 * Copyright (c) 2003, 2014, 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 com.sun.security.sasl;
27
28 import javax.security.sasl.SaslException;
29 import javax.security.sasl.Sasl;
30
31 // For HMAC_MD5
32 import java.security.NoSuchAlgorithmException;
33 import java.security.MessageDigest;
34
35 import java.util.Arrays;
36 import java.util.logging.Logger;
37
38 /**
39 * Base class for implementing CRAM-MD5 client and server mechanisms.
40 *
41 * @author Vincent Ryan
42 * @author Rosanna Lee
43 */
44 abstract class CramMD5Base {
45 protected boolean completed = false;
46 protected boolean aborted = false;
47 protected byte[] pw;
48
49 protected CramMD5Base() {
50 initLogger();
51 }
52
53 /**
54 * Retrieves this mechanism's name.
55 *
56 * @return The string "CRAM-MD5".
57 */
58 public String getMechanismName() {
59 return "CRAM-MD5";
60 }
61
62 /**
63 * Determines whether this mechanism has completed.
64 * CRAM-MD5 completes after processing one challenge from the server.
65 *
66 * @return true if has completed; false otherwise;
67 */
68 public boolean isComplete() {
69 return completed;
70 }
71
72 /**
73 * Unwraps the incoming buffer. CRAM-MD5 supports no security layer.
74 *
75 * @throws SaslException If attempt to use this method.
76 */
77 public byte[] unwrap(byte[] incoming, int offset, int len)
78 throws SaslException {
79 if (completed) {
80 throw new IllegalStateException(
81 "CRAM-MD5 supports neither integrity nor privacy");
82 } else {
83 throw new IllegalStateException(
84 "CRAM-MD5 authentication not completed");
85 }
86 }
87
88 /**
89 * Wraps the outgoing buffer. CRAM-MD5 supports no security layer.
90 *
91 * @throws SaslException If attempt to use this method.
92 */
93 public byte[] wrap(byte[] outgoing, int offset, int len) throws SaslException {
94 if (completed) {
95 throw new IllegalStateException(
96 "CRAM-MD5 supports neither integrity nor privacy");
97 } else {
98 throw new IllegalStateException(
99 "CRAM-MD5 authentication not completed");
100 }
101 }
102
103 /**
104 * Retrieves the negotiated property.
105 * This method can be called only after the authentication exchange has
106 * completed (i.e., when <tt>isComplete()</tt> returns true); otherwise, a
107 * <tt>SaslException</tt> is thrown.
108 *
109 * @return value of property; only QOP is applicable to CRAM-MD5.
110 * @exception IllegalStateException if this authentication exchange has not completed
111 */
112 public Object getNegotiatedProperty(String propName) {
113 if (completed) {
114 if (propName.equals(Sasl.QOP)) {
115 return "auth";
116 } else {
117 return null;
118 }
119 } else {
120 throw new IllegalStateException(
121 "CRAM-MD5 authentication not completed");
122 }
123 }
124
125 public void dispose() throws SaslException {
126 clearPassword();
127 }
128
129 protected void clearPassword() {
130 if (pw != null) {
131 // zero out password
132 for (int i = 0; i < pw.length; i++) {
133 pw[i] = (byte)0;
134 }
135 pw = null;
136 }
137 }
138
139 protected void finalize() {
140 clearPassword();
141 }
142
143 static private final int MD5_BLOCKSIZE = 64;
144 /**
145 * Hashes its input arguments according to HMAC-MD5 (RFC 2104)
146 * and returns the resulting digest in its ASCII representation.
147 *
148 * HMAC-MD5 function is described as follows:
149 *
150 * MD5(key XOR opad, MD5(key XOR ipad, text))
151 *
152 * where key is an n byte key
153 * ipad is the byte 0x36 repeated 64 times
154 * opad is the byte 0x5c repeated 64 times
155 * text is the data to be protected
156 */
157 final static String HMAC_MD5(byte[] key, byte[] text)
158 throws NoSuchAlgorithmException {
159
160 MessageDigest md5 = MessageDigest.getInstance("MD5");
161
162 /* digest the key if longer than 64 bytes */
163 if (key.length > MD5_BLOCKSIZE) {
164 key = md5.digest(key);
165 }
166
167 byte[] ipad = new byte[MD5_BLOCKSIZE]; /* inner padding */
168 byte[] opad = new byte[MD5_BLOCKSIZE]; /* outer padding */
169 byte[] digest;
170 int i;
171
172 /* store key in pads */
173 for (i = 0; i < key.length; i++) {
174 ipad[i] = key[i];
175 opad[i] = key[i];
176 }
177
178 /* XOR key with pads */
179 for (i = 0; i < MD5_BLOCKSIZE; i++) {
180 ipad[i] ^= 0x36;
181 opad[i] ^= 0x5c;
182 }
183
184 /* inner MD5 */
185 md5.update(ipad);
186 md5.update(text);
187 digest = md5.digest();
188
189 /* outer MD5 */
190 md5.update(opad);
191 md5.update(digest);
192 digest = md5.digest();
193
194 // Get character representation of digest
195 StringBuilder digestString = new StringBuilder();
196
197 for (i = 0; i < digest.length; i++) {
198 if ((digest[i] & 0x000000ff) < 0x10) {
199 digestString.append("0" +
200 Integer.toHexString(digest[i] & 0x000000ff));
201 } else {
202 digestString.append(
203 Integer.toHexString(digest[i] & 0x000000ff));
204 }
205 }
206
207 Arrays.fill(ipad, (byte)0);
208 Arrays.fill(opad, (byte)0);
209 ipad = null;
210 opad = null;
211
212 return (digestString.toString());
213 }
214
215 /**
216 * Sets logger field.
217 */
218 private static synchronized void initLogger() {
219 if (logger == null) {
220 logger = Logger.getLogger(SASL_LOGGER_NAME);
221 }
222 }
223 /**
224 * Logger for debug messages
225 */
226 private static final String SASL_LOGGER_NAME = "javax.security.sasl";
227 protected static Logger logger; // set in initLogger(); lazily loads logger
228 }