1 /*
2 * Copyright (c) 2000, 2011, 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 /*
27 * (C) Copyright IBM Corp. 1999 All Rights Reserved.
28 * Copyright 1997 The Open Group Research Institute. All rights reserved.
29 */
30
31 package sun.security.krb5;
32
33 import java.util.Arrays;
34 import sun.security.util.*;
35 import sun.security.krb5.internal.*;
36 import sun.security.krb5.internal.crypto.*;
37 import java.io.IOException;
38 import java.math.BigInteger;
39
40 /**
41 * This class encapsulates the concept of a Kerberos checksum.
42 */
43 public class Checksum {
44
45 private int cksumType;
46 private byte[] checksum;
47
48 // ----------------------------------------------+-------------+-----------
49 // Checksum type |sumtype |checksum
50 // |value | size
51 // ----------------------------------------------+-------------+-----------
52 public static final int CKSUMTYPE_NULL = 0; // 0
53 public static final int CKSUMTYPE_CRC32 = 1; // 4
54 public static final int CKSUMTYPE_RSA_MD4 = 2; // 16
55 public static final int CKSUMTYPE_RSA_MD4_DES = 3; // 24
56 public static final int CKSUMTYPE_DES_MAC = 4; // 16
57 public static final int CKSUMTYPE_DES_MAC_K = 5; // 8
58 public static final int CKSUMTYPE_RSA_MD4_DES_K = 6; // 16
59 public static final int CKSUMTYPE_RSA_MD5 = 7; // 16
60 public static final int CKSUMTYPE_RSA_MD5_DES = 8; // 24
61
62 // draft-ietf-krb-wg-crypto-07.txt
63 public static final int CKSUMTYPE_HMAC_SHA1_DES3_KD = 12; // 20
64
65 // draft-raeburn-krb-rijndael-krb-07.txt
66 public static final int CKSUMTYPE_HMAC_SHA1_96_AES128 = 15; // 96
67 public static final int CKSUMTYPE_HMAC_SHA1_96_AES256 = 16; // 96
68
69 // draft-brezak-win2k-krb-rc4-hmac-04.txt
70 public static final int CKSUMTYPE_HMAC_MD5_ARCFOUR = -138;
71
72 static int CKSUMTYPE_DEFAULT;
73 static int SAFECKSUMTYPE_DEFAULT;
74
75 private static boolean DEBUG = Krb5.DEBUG;
76 static {
77 String temp = null;
78 Config cfg = null;
79 try {
80 cfg = Config.getInstance();
81 temp = cfg.getDefault("default_checksum", "libdefaults");
82 if (temp != null)
83 {
84 CKSUMTYPE_DEFAULT = cfg.getType(temp);
85 } else {
86 /*
87 * If the default checksum is not
88 * specified in the configuration we
89 * set it to RSA_MD5. We follow the MIT and
90 * SEAM implementation.
91 */
92 CKSUMTYPE_DEFAULT = CKSUMTYPE_RSA_MD5;
93 }
94 } catch (Exception exc) {
95 if (DEBUG) {
96 System.out.println("Exception in getting default checksum "+
97 "value from the configuration " +
98 "Setting default checksum to be RSA-MD5");
99 exc.printStackTrace();
100 }
101 CKSUMTYPE_DEFAULT = CKSUMTYPE_RSA_MD5;
102 }
103
104
105 try {
106 temp = cfg.getDefault("safe_checksum_type", "libdefaults");
107 if (temp != null)
108 {
109 SAFECKSUMTYPE_DEFAULT = cfg.getType(temp);
110 } else {
111 SAFECKSUMTYPE_DEFAULT = CKSUMTYPE_RSA_MD5_DES;
112 }
113 } catch (Exception exc) {
114 if (DEBUG) {
115 System.out.println("Exception in getting safe default " +
116 "checksum value " +
117 "from the configuration Setting " +
118 "safe default checksum to be RSA-MD5");
119 exc.printStackTrace();
120 }
121 SAFECKSUMTYPE_DEFAULT = CKSUMTYPE_RSA_MD5_DES;
122 }
123 }
124
125 /**
126 * Constructs a new Checksum using the raw data and type.
127 * @data the byte array of checksum.
128 * @new_cksumType the type of checksum.
129 *
130 */
131 // used in InitialToken
132 public Checksum(byte[] data, int new_cksumType) {
133 cksumType = new_cksumType;
134 checksum = data;
135 }
136
137 /**
138 * Constructs a new Checksum by calculating the checksum over the data
139 * using specified checksum type.
140 * @new_cksumType the type of checksum.
141 * @data the data that needs to be performed a checksum calculation on.
142 */
143 public Checksum(int new_cksumType, byte[] data)
144 throws KdcErrException, KrbCryptoException {
145
146 cksumType = new_cksumType;
147 CksumType cksumEngine = CksumType.getInstance(cksumType);
148 if (!cksumEngine.isSafe()) {
149 checksum = cksumEngine.calculateChecksum(data, data.length);
150 } else {
151 throw new KdcErrException(Krb5.KRB_AP_ERR_INAPP_CKSUM);
152 }
153 }
154
155 /**
156 * Constructs a new Checksum by calculating the keyed checksum
157 * over the data using specified checksum type.
158 * @new_cksumType the type of checksum.
159 * @data the data that needs to be performed a checksum calculation on.
160 */
161 // KrbSafe, KrbTgsReq
162 public Checksum(int new_cksumType, byte[] data,
163 EncryptionKey key, int usage)
164 throws KdcErrException, KrbApErrException, KrbCryptoException {
165 cksumType = new_cksumType;
166 CksumType cksumEngine = CksumType.getInstance(cksumType);
167 if (!cksumEngine.isSafe())
168 throw new KrbApErrException(Krb5.KRB_AP_ERR_INAPP_CKSUM);
169 checksum =
170 cksumEngine.calculateKeyedChecksum(data,
171 data.length,
172 key.getBytes(),
173 usage);
174 }
175
176 /**
177 * Verifies the keyed checksum over the data passed in.
178 */
179 public boolean verifyKeyedChecksum(byte[] data, EncryptionKey key,
180 int usage)
181 throws KdcErrException, KrbApErrException, KrbCryptoException {
182 CksumType cksumEngine = CksumType.getInstance(cksumType);
183 if (!cksumEngine.isSafe())
184 throw new KrbApErrException(Krb5.KRB_AP_ERR_INAPP_CKSUM);
185 return cksumEngine.verifyKeyedChecksum(data,
186 data.length,
187 key.getBytes(),
188 checksum,
189 usage);
190 }
191
192 /*
193 public Checksum(byte[] data) throws KdcErrException, KrbCryptoException {
194 this(Checksum.CKSUMTYPE_DEFAULT, data);
195 }
196 */
197
198 boolean isEqual(Checksum cksum) throws KdcErrException {
199 if (cksumType != cksum.cksumType)
200 return false;
201 CksumType cksumEngine = CksumType.getInstance(cksumType);
202 return CksumType.isChecksumEqual(checksum, cksum.checksum);
203 }
204
205 /**
206 * Constructs an instance of Checksum from an ASN.1 encoded representation.
207 * @param encoding a single DER-encoded value.
208 * @exception Asn1Exception if an error occurs while decoding an ASN1
209 * encoded data.
210 * @exception IOException if an I/O error occurs while reading encoded data.
211 *
212 */
213 private Checksum(DerValue encoding) throws Asn1Exception, IOException {
214 DerValue der;
215 if (encoding.getTag() != DerValue.tag_Sequence) {
216 throw new Asn1Exception(Krb5.ASN1_BAD_ID);
217 }
218 der = encoding.getData().getDerValue();
219 if ((der.getTag() & (byte)0x1F) == (byte)0x00) {
220 cksumType = der.getData().getBigInteger().intValue();
221 }
222 else
223 throw new Asn1Exception(Krb5.ASN1_BAD_ID);
224 der = encoding.getData().getDerValue();
225 if ((der.getTag() & (byte)0x1F) == (byte)0x01) {
226 checksum = der.getData().getOctetString();
227 }
228 else
229 throw new Asn1Exception(Krb5.ASN1_BAD_ID);
230 if (encoding.getData().available() > 0) {
231 throw new Asn1Exception(Krb5.ASN1_BAD_ID);
232 }
233 }
234
235 /**
236 * Encodes a Checksum object.
237 * <xmp>
238 * Checksum ::= SEQUENCE {
239 * cksumtype [0] Int32,
240 * checksum [1] OCTET STRING
241 * }
242 * </xmp>
243 *
244 * <p>
245 * This definition reflects the Network Working Group RFC 4120
246 * specification available at
247 * <a href="http://www.ietf.org/rfc/rfc4120.txt">
248 * http://www.ietf.org/rfc/rfc4120.txt</a>.
249 * @return byte array of enocded Checksum.
250 * @exception Asn1Exception if an error occurs while decoding an
251 * ASN1 encoded data.
252 * @exception IOException if an I/O error occurs while reading
253 * encoded data.
254 *
255 */
256 public byte[] asn1Encode() throws Asn1Exception, IOException {
257 DerOutputStream bytes = new DerOutputStream();
258 DerOutputStream temp = new DerOutputStream();
259 temp.putInteger(BigInteger.valueOf(cksumType));
260 bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,
261 true, (byte)0x00), temp);
262 temp = new DerOutputStream();
263 temp.putOctetString(checksum);
264 bytes.write(DerValue.createTag(DerValue.TAG_CONTEXT,
265 true, (byte)0x01), temp);
266 temp = new DerOutputStream();
267 temp.write(DerValue.tag_Sequence, bytes);
268 return temp.toByteArray();
269 }
270
271
272 /**
273 * Parse (unmarshal) a checksum object from a DER input stream. This form
274 * parsing might be used when expanding a value which is part of
275 * a constructed sequence and uses explicitly tagged type.
276 *
277 * @exception Asn1Exception if an error occurs while decoding an
278 * ASN1 encoded data.
279 * @exception IOException if an I/O error occurs while reading
280 * encoded data.
281 * @param data the Der input stream value, which contains one or more
282 * marshaled value.
283 * @param explicitTag tag number.
284 * @param optional indicates if this data field is optional
285 * @return an instance of Checksum.
286 *
287 */
288 public static Checksum parse(DerInputStream data,
289 byte explicitTag, boolean optional)
290 throws Asn1Exception, IOException {
291
292 if ((optional) &&
293 (((byte)data.peekByte() & (byte)0x1F) != explicitTag)) {
294 return null;
295 }
296 DerValue der = data.getDerValue();
297 if (explicitTag != (der.getTag() & (byte)0x1F)) {
298 throw new Asn1Exception(Krb5.ASN1_BAD_ID);
299 } else {
300 DerValue subDer = der.getData().getDerValue();
301 return new Checksum(subDer);
302 }
303 }
304
305 /**
306 * Returns the raw bytes of the checksum, not in ASN.1 encoded form.
307 */
308 public final byte[] getBytes() {
309 return checksum;
310 }
311
312 public final int getType() {
313 return cksumType;
314 }
315
316 @Override public boolean equals(Object obj) {
317 if (this == obj) {
318 return true;
319 }
320 if (!(obj instanceof Checksum)) {
321 return false;
322 }
323
324 try {
325 return isEqual((Checksum)obj);
326 } catch (KdcErrException kee) {
327 return false;
328 }
329 }
330
331 @Override public int hashCode() {
332 int result = 17;
333 result = 37 * result + cksumType;
334 if (checksum != null) {
335 result = 37 * result + Arrays.hashCode(checksum);
336 }
337 return result;
338 }
339 }