2
|
1 |
/*
|
5506
|
2 |
* Copyright (c) 2005, 2008, Oracle and/or its affiliates. All rights reserved.
|
2
|
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
|
5506
|
7 |
* published by the Free Software Foundation. Oracle designates this
|
2
|
8 |
* particular file as subject to the "Classpath" exception as provided
|
5506
|
9 |
* by Oracle in the LICENSE file that accompanied this code.
|
2
|
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 |
*
|
5506
|
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.
|
2
|
24 |
*/
|
|
25 |
|
|
26 |
package sun.security.krb5.internal.crypto.dk;
|
|
27 |
|
|
28 |
import java.security.*;
|
|
29 |
import javax.crypto.*;
|
|
30 |
import javax.crypto.spec.*;
|
|
31 |
import java.util.*;
|
|
32 |
import sun.security.krb5.EncryptedData;
|
|
33 |
import sun.security.krb5.KrbCryptoException;
|
|
34 |
import sun.security.krb5.Confounder;
|
|
35 |
import sun.security.krb5.internal.crypto.KeyUsage;
|
|
36 |
|
|
37 |
/**
|
|
38 |
* Support for ArcFour in Kerberos
|
|
39 |
* as defined in RFC 4757.
|
|
40 |
* http://www.ietf.org/rfc/rfc4757.txt
|
|
41 |
*
|
|
42 |
* @author Seema Malkani
|
|
43 |
*/
|
|
44 |
|
|
45 |
public class ArcFourCrypto extends DkCrypto {
|
|
46 |
|
|
47 |
private static final boolean debug = false;
|
|
48 |
|
|
49 |
private static final int confounderSize = 8;
|
|
50 |
private static final byte[] ZERO_IV = new byte[] {0, 0, 0, 0, 0, 0, 0, 0};
|
|
51 |
private static final int hashSize = 16;
|
|
52 |
private final int keyLength;
|
|
53 |
|
|
54 |
public ArcFourCrypto(int length) {
|
|
55 |
keyLength = length;
|
|
56 |
}
|
|
57 |
|
|
58 |
protected int getKeySeedLength() {
|
|
59 |
return keyLength; // bits; RC4 key material
|
|
60 |
}
|
|
61 |
|
|
62 |
protected byte[] randomToKey(byte[] in) {
|
|
63 |
// simple identity operation
|
|
64 |
return in;
|
|
65 |
}
|
|
66 |
|
|
67 |
public byte[] stringToKey(char[] passwd)
|
|
68 |
throws GeneralSecurityException {
|
|
69 |
return stringToKey(passwd, null);
|
|
70 |
}
|
|
71 |
|
|
72 |
/*
|
|
73 |
* String2Key(Password)
|
|
74 |
* K = MD4(UNICODE(password))
|
|
75 |
*/
|
|
76 |
private byte[] stringToKey(char[] secret, byte[] opaque)
|
|
77 |
throws GeneralSecurityException {
|
|
78 |
|
|
79 |
if (opaque != null && opaque.length > 0) {
|
|
80 |
throw new RuntimeException("Invalid parameter to stringToKey");
|
|
81 |
}
|
|
82 |
|
|
83 |
byte[] passwd = null;
|
|
84 |
byte[] digest = null;
|
|
85 |
try {
|
|
86 |
// convert ascii to unicode
|
|
87 |
passwd = charToUtf16(secret);
|
|
88 |
|
|
89 |
// provider for MD4
|
|
90 |
MessageDigest md = sun.security.provider.MD4.getInstance();
|
|
91 |
md.update(passwd);
|
|
92 |
digest = md.digest();
|
|
93 |
} catch (Exception e) {
|
|
94 |
return null;
|
|
95 |
} finally {
|
|
96 |
if (passwd != null) {
|
|
97 |
Arrays.fill(passwd, (byte)0);
|
|
98 |
}
|
|
99 |
}
|
|
100 |
|
|
101 |
return digest;
|
|
102 |
}
|
|
103 |
|
|
104 |
protected Cipher getCipher(byte[] key, byte[] ivec, int mode)
|
|
105 |
throws GeneralSecurityException {
|
|
106 |
|
|
107 |
// IV
|
|
108 |
if (ivec == null) {
|
|
109 |
ivec = ZERO_IV;
|
|
110 |
}
|
|
111 |
SecretKeySpec secretKey = new SecretKeySpec(key, "ARCFOUR");
|
|
112 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
113 |
IvParameterSpec encIv = new IvParameterSpec(ivec, 0, ivec.length);
|
|
114 |
cipher.init(mode, secretKey, encIv);
|
|
115 |
return cipher;
|
|
116 |
}
|
|
117 |
|
|
118 |
public int getChecksumLength() {
|
|
119 |
return hashSize; // bytes
|
|
120 |
}
|
|
121 |
|
|
122 |
/**
|
|
123 |
* Get the HMAC-MD5
|
|
124 |
*/
|
|
125 |
protected byte[] getHmac(byte[] key, byte[] msg)
|
|
126 |
throws GeneralSecurityException {
|
|
127 |
|
|
128 |
SecretKey keyKi = new SecretKeySpec(key, "HmacMD5");
|
|
129 |
Mac m = Mac.getInstance("HmacMD5");
|
|
130 |
m.init(keyKi);
|
|
131 |
|
|
132 |
// generate hash
|
|
133 |
byte[] hash = m.doFinal(msg);
|
|
134 |
return hash;
|
|
135 |
}
|
|
136 |
|
|
137 |
/**
|
|
138 |
* Calculate the checksum
|
|
139 |
*/
|
|
140 |
public byte[] calculateChecksum(byte[] baseKey, int usage, byte[] input,
|
|
141 |
int start, int len) throws GeneralSecurityException {
|
|
142 |
|
|
143 |
if (debug) {
|
|
144 |
System.out.println("ARCFOUR: calculateChecksum with usage = " +
|
|
145 |
usage);
|
|
146 |
}
|
|
147 |
|
|
148 |
if (!KeyUsage.isValid(usage)) {
|
|
149 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
150 |
+ usage);
|
|
151 |
}
|
|
152 |
|
|
153 |
byte[] Ksign = null;
|
|
154 |
// Derive signing key from session key
|
|
155 |
try {
|
|
156 |
byte[] ss = "signaturekey".getBytes();
|
|
157 |
// need to append end-of-string 00
|
|
158 |
byte[] new_ss = new byte[ss.length+1];
|
|
159 |
System.arraycopy(ss, 0, new_ss, 0, ss.length);
|
|
160 |
Ksign = getHmac(baseKey, new_ss);
|
|
161 |
} catch (Exception e) {
|
|
162 |
GeneralSecurityException gse =
|
|
163 |
new GeneralSecurityException("Calculate Checkum Failed!");
|
|
164 |
gse.initCause(e);
|
|
165 |
throw gse;
|
|
166 |
}
|
|
167 |
|
|
168 |
// get the salt using key usage
|
|
169 |
byte[] salt = getSalt(usage);
|
|
170 |
|
|
171 |
// Generate checksum of message
|
|
172 |
MessageDigest messageDigest = null;
|
|
173 |
try {
|
|
174 |
messageDigest = MessageDigest.getInstance("MD5");
|
|
175 |
} catch (NoSuchAlgorithmException e) {
|
|
176 |
GeneralSecurityException gse =
|
|
177 |
new GeneralSecurityException("Calculate Checkum Failed!");
|
|
178 |
gse.initCause(e);
|
|
179 |
throw gse;
|
|
180 |
}
|
|
181 |
messageDigest.update(salt);
|
|
182 |
messageDigest.update(input, start, len);
|
|
183 |
byte[] md5tmp = messageDigest.digest();
|
|
184 |
|
|
185 |
// Generate checksum
|
|
186 |
byte[] hmac = getHmac(Ksign, md5tmp);
|
|
187 |
if (debug) {
|
|
188 |
traceOutput("hmac", hmac, 0, hmac.length);
|
|
189 |
}
|
|
190 |
if (hmac.length == getChecksumLength()) {
|
|
191 |
return hmac;
|
|
192 |
} else if (hmac.length > getChecksumLength()) {
|
|
193 |
byte[] buf = new byte[getChecksumLength()];
|
|
194 |
System.arraycopy(hmac, 0, buf, 0, buf.length);
|
|
195 |
return buf;
|
|
196 |
} else {
|
|
197 |
throw new GeneralSecurityException("checksum size too short: " +
|
|
198 |
hmac.length + "; expecting : " + getChecksumLength());
|
|
199 |
}
|
|
200 |
}
|
|
201 |
|
|
202 |
/**
|
|
203 |
* Performs encryption of Sequence Number using derived key.
|
|
204 |
*/
|
|
205 |
public byte[] encryptSeq(byte[] baseKey, int usage,
|
|
206 |
byte[] checksum, byte[] plaintext, int start, int len)
|
|
207 |
throws GeneralSecurityException, KrbCryptoException {
|
|
208 |
|
|
209 |
if (!KeyUsage.isValid(usage)) {
|
|
210 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
211 |
+ usage);
|
|
212 |
}
|
|
213 |
// derive encryption for sequence number
|
|
214 |
byte[] salt = new byte[4];
|
|
215 |
byte[] kSeq = getHmac(baseKey, salt);
|
|
216 |
|
|
217 |
// derive new encryption key salted with sequence number
|
|
218 |
kSeq = getHmac(kSeq, checksum);
|
|
219 |
|
|
220 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
221 |
SecretKeySpec secretKey = new SecretKeySpec(kSeq, "ARCFOUR");
|
|
222 |
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
|
|
223 |
byte[] output = cipher.doFinal(plaintext, start, len);
|
|
224 |
|
|
225 |
return output;
|
|
226 |
}
|
|
227 |
|
|
228 |
/**
|
|
229 |
* Performs decryption of Sequence Number using derived key.
|
|
230 |
*/
|
|
231 |
public byte[] decryptSeq(byte[] baseKey, int usage,
|
|
232 |
byte[] checksum, byte[] ciphertext, int start, int len)
|
|
233 |
throws GeneralSecurityException, KrbCryptoException {
|
|
234 |
|
|
235 |
if (!KeyUsage.isValid(usage)) {
|
|
236 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
237 |
+ usage);
|
|
238 |
}
|
|
239 |
|
|
240 |
// derive decryption for sequence number
|
|
241 |
byte[] salt = new byte[4];
|
|
242 |
byte[] kSeq = getHmac(baseKey, salt);
|
|
243 |
|
|
244 |
// derive new encryption key salted with sequence number
|
|
245 |
kSeq = getHmac(kSeq, checksum);
|
|
246 |
|
|
247 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
248 |
SecretKeySpec secretKey = new SecretKeySpec(kSeq, "ARCFOUR");
|
|
249 |
cipher.init(Cipher.DECRYPT_MODE, secretKey);
|
|
250 |
byte[] output = cipher.doFinal(ciphertext, start, len);
|
|
251 |
|
|
252 |
return output;
|
|
253 |
}
|
|
254 |
|
|
255 |
/**
|
|
256 |
* Performs encryption using derived key; adds confounder.
|
|
257 |
*/
|
|
258 |
public byte[] encrypt(byte[] baseKey, int usage,
|
|
259 |
byte[] ivec, byte[] new_ivec, byte[] plaintext, int start, int len)
|
|
260 |
throws GeneralSecurityException, KrbCryptoException {
|
|
261 |
|
|
262 |
if (!KeyUsage.isValid(usage)) {
|
|
263 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
264 |
+ usage);
|
|
265 |
}
|
|
266 |
|
|
267 |
if (debug) {
|
|
268 |
System.out.println("ArcFour: ENCRYPT with key usage = " + usage);
|
|
269 |
}
|
|
270 |
|
|
271 |
// get the confounder
|
|
272 |
byte[] confounder = Confounder.bytes(confounderSize);
|
|
273 |
|
|
274 |
// add confounder to the plaintext for encryption
|
|
275 |
int plainSize = roundup(confounder.length + len, 1);
|
|
276 |
byte[] toBeEncrypted = new byte[plainSize];
|
|
277 |
System.arraycopy(confounder, 0, toBeEncrypted, 0, confounder.length);
|
|
278 |
System.arraycopy(plaintext, start, toBeEncrypted,
|
|
279 |
confounder.length, len);
|
|
280 |
|
|
281 |
/* begin the encryption, compute K1 */
|
|
282 |
byte[] k1 = new byte[baseKey.length];
|
|
283 |
System.arraycopy(baseKey, 0, k1, 0, baseKey.length);
|
|
284 |
|
|
285 |
// get the salt using key usage
|
|
286 |
byte[] salt = getSalt(usage);
|
|
287 |
|
|
288 |
// compute K2 using K1
|
|
289 |
byte[] k2 = getHmac(k1, salt);
|
|
290 |
|
|
291 |
// generate checksum using K2
|
|
292 |
byte[] checksum = getHmac(k2, toBeEncrypted);
|
|
293 |
|
|
294 |
// compute K3 using K2 and checksum
|
|
295 |
byte[] k3 = getHmac(k2, checksum);
|
|
296 |
|
|
297 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
298 |
SecretKeySpec secretKey = new SecretKeySpec(k3, "ARCFOUR");
|
|
299 |
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
|
|
300 |
byte[] output = cipher.doFinal(toBeEncrypted, 0, toBeEncrypted.length);
|
|
301 |
|
|
302 |
// encryptedData + HMAC
|
|
303 |
byte[] result = new byte[hashSize + output.length];
|
|
304 |
System.arraycopy(checksum, 0, result, 0, hashSize);
|
|
305 |
System.arraycopy(output, 0, result, hashSize, output.length);
|
|
306 |
|
|
307 |
return result;
|
|
308 |
}
|
|
309 |
|
|
310 |
/**
|
|
311 |
* Performs encryption using derived key; does not add confounder.
|
|
312 |
*/
|
|
313 |
public byte[] encryptRaw(byte[] baseKey, int usage,
|
|
314 |
byte[] seqNum, byte[] plaintext, int start, int len)
|
|
315 |
throws GeneralSecurityException, KrbCryptoException {
|
|
316 |
|
|
317 |
if (!KeyUsage.isValid(usage)) {
|
|
318 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
319 |
+ usage);
|
|
320 |
}
|
|
321 |
|
|
322 |
if (debug) {
|
|
323 |
System.out.println("\nARCFOUR: encryptRaw with usage = " + usage);
|
|
324 |
}
|
|
325 |
|
|
326 |
// Derive encryption key for data
|
|
327 |
// Key derivation salt = 0
|
|
328 |
byte[] klocal = new byte[baseKey.length];
|
|
329 |
for (int i = 0; i <= 15; i++) {
|
|
330 |
klocal[i] = (byte) (baseKey[i] ^ 0xF0);
|
|
331 |
}
|
|
332 |
byte[] salt = new byte[4];
|
|
333 |
byte[] kcrypt = getHmac(klocal, salt);
|
|
334 |
|
|
335 |
// Note: When using this RC4 based encryption type, the sequence number
|
|
336 |
// is always sent in big-endian rather than little-endian order.
|
|
337 |
|
|
338 |
// new encryption key salted with sequence number
|
|
339 |
kcrypt = getHmac(kcrypt, seqNum);
|
|
340 |
|
|
341 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
342 |
SecretKeySpec secretKey = new SecretKeySpec(kcrypt, "ARCFOUR");
|
|
343 |
cipher.init(Cipher.ENCRYPT_MODE, secretKey);
|
|
344 |
byte[] output = cipher.doFinal(plaintext, start, len);
|
|
345 |
|
|
346 |
return output;
|
|
347 |
}
|
|
348 |
|
|
349 |
/**
|
|
350 |
* @param baseKey key from which keys are to be derived using usage
|
|
351 |
* @param ciphertext E(Ke, conf | plaintext | padding, ivec) | H1[1..h]
|
|
352 |
*/
|
|
353 |
public byte[] decrypt(byte[] baseKey, int usage, byte[] ivec,
|
|
354 |
byte[] ciphertext, int start, int len)
|
|
355 |
throws GeneralSecurityException {
|
|
356 |
|
|
357 |
if (!KeyUsage.isValid(usage)) {
|
|
358 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
359 |
+ usage);
|
|
360 |
}
|
|
361 |
if (debug) {
|
|
362 |
System.out.println("\nARCFOUR: DECRYPT using key usage = " + usage);
|
|
363 |
}
|
|
364 |
|
|
365 |
// compute K1
|
|
366 |
byte[] k1 = new byte[baseKey.length];
|
|
367 |
System.arraycopy(baseKey, 0, k1, 0, baseKey.length);
|
|
368 |
|
|
369 |
// get the salt using key usage
|
|
370 |
byte[] salt = getSalt(usage);
|
|
371 |
|
|
372 |
// compute K2 using K1
|
|
373 |
byte[] k2 = getHmac(k1, salt);
|
|
374 |
|
|
375 |
// compute K3 using K2 and checksum
|
|
376 |
byte[] checksum = new byte[hashSize];
|
|
377 |
System.arraycopy(ciphertext, start, checksum, 0, hashSize);
|
|
378 |
byte[] k3 = getHmac(k2, checksum);
|
|
379 |
|
|
380 |
// Decrypt [confounder | plaintext ] (without checksum)
|
|
381 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
382 |
SecretKeySpec secretKey = new SecretKeySpec(k3, "ARCFOUR");
|
|
383 |
cipher.init(Cipher.DECRYPT_MODE, secretKey);
|
|
384 |
byte[] plaintext = cipher.doFinal(ciphertext, start+hashSize,
|
|
385 |
len-hashSize);
|
|
386 |
|
|
387 |
// Verify checksum
|
|
388 |
byte[] calculatedHmac = getHmac(k2, plaintext);
|
|
389 |
if (debug) {
|
|
390 |
traceOutput("calculated Hmac", calculatedHmac, 0,
|
|
391 |
calculatedHmac.length);
|
|
392 |
traceOutput("message Hmac", ciphertext, 0,
|
|
393 |
hashSize);
|
|
394 |
}
|
|
395 |
boolean cksumFailed = false;
|
|
396 |
if (calculatedHmac.length >= hashSize) {
|
|
397 |
for (int i = 0; i < hashSize; i++) {
|
|
398 |
if (calculatedHmac[i] != ciphertext[i]) {
|
|
399 |
cksumFailed = true;
|
77
|
400 |
if (debug) {
|
|
401 |
System.err.println("Checksum failed !");
|
|
402 |
}
|
2
|
403 |
break;
|
|
404 |
}
|
|
405 |
}
|
|
406 |
}
|
|
407 |
if (cksumFailed) {
|
|
408 |
throw new GeneralSecurityException("Checksum failed");
|
|
409 |
}
|
|
410 |
|
|
411 |
// Get rid of confounder
|
|
412 |
// [ confounder | plaintext ]
|
|
413 |
byte[] output = new byte[plaintext.length - confounderSize];
|
|
414 |
System.arraycopy(plaintext, confounderSize, output, 0, output.length);
|
|
415 |
|
|
416 |
return output;
|
|
417 |
}
|
|
418 |
|
|
419 |
/**
|
|
420 |
* Decrypts data using specified key and initial vector.
|
|
421 |
* @param baseKey encryption key to use
|
|
422 |
* @param ciphertext encrypted data to be decrypted
|
|
423 |
* @param usage ignored
|
|
424 |
*/
|
|
425 |
public byte[] decryptRaw(byte[] baseKey, int usage, byte[] ivec,
|
|
426 |
byte[] ciphertext, int start, int len, byte[] seqNum)
|
|
427 |
throws GeneralSecurityException {
|
|
428 |
|
|
429 |
if (!KeyUsage.isValid(usage)) {
|
|
430 |
throw new GeneralSecurityException("Invalid key usage number: "
|
|
431 |
+ usage);
|
|
432 |
}
|
|
433 |
if (debug) {
|
|
434 |
System.out.println("\nARCFOUR: decryptRaw with usage = " + usage);
|
|
435 |
}
|
|
436 |
|
|
437 |
// Derive encryption key for data
|
|
438 |
// Key derivation salt = 0
|
|
439 |
byte[] klocal = new byte[baseKey.length];
|
|
440 |
for (int i = 0; i <= 15; i++) {
|
|
441 |
klocal[i] = (byte) (baseKey[i] ^ 0xF0);
|
|
442 |
}
|
|
443 |
byte[] salt = new byte[4];
|
|
444 |
byte[] kcrypt = getHmac(klocal, salt);
|
|
445 |
|
|
446 |
// need only first 4 bytes of sequence number
|
|
447 |
byte[] sequenceNum = new byte[4];
|
|
448 |
System.arraycopy(seqNum, 0, sequenceNum, 0, sequenceNum.length);
|
|
449 |
|
|
450 |
// new encryption key salted with sequence number
|
|
451 |
kcrypt = getHmac(kcrypt, sequenceNum);
|
|
452 |
|
|
453 |
Cipher cipher = Cipher.getInstance("ARCFOUR");
|
|
454 |
SecretKeySpec secretKey = new SecretKeySpec(kcrypt, "ARCFOUR");
|
|
455 |
cipher.init(Cipher.DECRYPT_MODE, secretKey);
|
|
456 |
byte[] output = cipher.doFinal(ciphertext, start, len);
|
|
457 |
|
|
458 |
return output;
|
|
459 |
}
|
|
460 |
|
|
461 |
// get the salt using key usage
|
|
462 |
private byte[] getSalt(int usage) {
|
|
463 |
int ms_usage = arcfour_translate_usage(usage);
|
|
464 |
byte[] salt = new byte[4];
|
|
465 |
salt[0] = (byte)(ms_usage & 0xff);
|
|
466 |
salt[1] = (byte)((ms_usage >> 8) & 0xff);
|
|
467 |
salt[2] = (byte)((ms_usage >> 16) & 0xff);
|
|
468 |
salt[3] = (byte)((ms_usage >> 24) & 0xff);
|
|
469 |
return salt;
|
|
470 |
}
|
|
471 |
|
|
472 |
// Key usage translation for MS
|
|
473 |
private int arcfour_translate_usage(int usage) {
|
|
474 |
switch (usage) {
|
|
475 |
case 3: return 8;
|
|
476 |
case 9: return 8;
|
|
477 |
case 23: return 13;
|
|
478 |
default: return usage;
|
|
479 |
}
|
|
480 |
}
|
|
481 |
|
|
482 |
}
|