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comparison app/src/main/java/ch/ethz/ssh2/channel/AuthAgentForwardThread.java @ 438:d29cce60f393

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migrate from Eclipse to Android Studio
author Carl Byington <carl@five-ten-sg.com>
date Thu, 03 Dec 2015 11:23:55 -0800
parents src/ch/ethz/ssh2/channel/AuthAgentForwardThread.java@b40bc65fa09a
children
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437:208b31032318 438:d29cce60f393
1 /*
2 * ConnectBot: simple, powerful, open-source SSH client for Android
3 * Copyright 2007 Kenny Root, Jeffrey Sharkey
4 *
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
8 *
9 * http://www.apache.org/licenses/LICENSE-2.0
10 *
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
16 */
17
18 package ch.ethz.ssh2.channel;
19
20 import java.io.IOException;
21 import java.io.InputStream;
22 import java.io.OutputStream;
23 import java.math.BigInteger;
24 import java.security.KeyFactory;
25 import java.security.KeyPair;
26 import java.security.NoSuchAlgorithmException;
27 import java.security.PrivateKey;
28 import java.security.PublicKey;
29 import java.security.interfaces.DSAPrivateKey;
30 import java.security.interfaces.ECPrivateKey;
31 import java.security.interfaces.RSAPrivateKey;
32 import java.security.spec.DSAPrivateKeySpec;
33 import java.security.spec.DSAPublicKeySpec;
34 import java.security.spec.ECParameterSpec;
35 import java.security.spec.ECPoint;
36 import java.security.spec.ECPrivateKeySpec;
37 import java.security.spec.ECPublicKeySpec;
38 import java.security.spec.InvalidKeySpecException;
39 import java.security.spec.KeySpec;
40 import java.security.spec.RSAPrivateCrtKeySpec;
41 import java.security.spec.RSAPublicKeySpec;
42 import java.util.Map;
43 import java.util.Map.Entry;
44
45 import ch.ethz.ssh2.AuthAgentCallback;
46 import ch.ethz.ssh2.crypto.SecureRandomFix;
47 import ch.ethz.ssh2.log.Logger;
48 import ch.ethz.ssh2.packets.TypesReader;
49 import ch.ethz.ssh2.packets.TypesWriter;
50 import ch.ethz.ssh2.signature.DSASHA1Verify;
51 import ch.ethz.ssh2.signature.ECDSASHA2Verify;
52 import ch.ethz.ssh2.signature.RSASHA1Verify;
53
54 /**
55 * AuthAgentForwardThread.
56 *
57 * @author Kenny Root
58 * @version $Id$
59 */
60 public class AuthAgentForwardThread extends Thread implements IChannelWorkerThread {
61 private static final byte[] SSH_AGENT_FAILURE = {0, 0, 0, 1, 5}; // 5
62 private static final byte[] SSH_AGENT_SUCCESS = {0, 0, 0, 1, 6}; // 6
63
64 private static final int SSH2_AGENTC_REQUEST_IDENTITIES = 11;
65 private static final int SSH2_AGENT_IDENTITIES_ANSWER = 12;
66
67 private static final int SSH2_AGENTC_SIGN_REQUEST = 13;
68 private static final int SSH2_AGENT_SIGN_RESPONSE = 14;
69
70 private static final int SSH2_AGENTC_ADD_IDENTITY = 17;
71 private static final int SSH2_AGENTC_REMOVE_IDENTITY = 18;
72 private static final int SSH2_AGENTC_REMOVE_ALL_IDENTITIES = 19;
73
74 // private static final int SSH_AGENTC_ADD_SMARTCARD_KEY = 20;
75 // private static final int SSH_AGENTC_REMOVE_SMARTCARD_KEY = 21;
76
77 private static final int SSH_AGENTC_LOCK = 22;
78 private static final int SSH_AGENTC_UNLOCK = 23;
79
80 private static final int SSH2_AGENTC_ADD_ID_CONSTRAINED = 25;
81 // private static final int SSH_AGENTC_ADD_SMARTCARD_KEY_CONSTRAINED = 26;
82
83 // Constraints for adding keys
84 private static final int SSH_AGENT_CONSTRAIN_LIFETIME = 1;
85 private static final int SSH_AGENT_CONSTRAIN_CONFIRM = 2;
86
87 // Flags for signature requests
88 // private static final int SSH_AGENT_OLD_SIGNATURE = 1;
89
90 private static final Logger log = Logger.getLogger(RemoteAcceptThread.class);
91
92 AuthAgentCallback authAgent;
93 OutputStream os;
94 InputStream is;
95 Channel c;
96
97 byte[] buffer = new byte[Channel.CHANNEL_BUFFER_SIZE];
98
99 public AuthAgentForwardThread(Channel c, AuthAgentCallback authAgent) {
100 this.c = c;
101 this.authAgent = authAgent;
102 log.debug("AuthAgentForwardThread started");
103 }
104
105 @Override
106 public void run() {
107 try {
108 c.cm.registerThread(this);
109 }
110 catch (IOException e) {
111 stopWorking();
112 return;
113 }
114
115 try {
116 c.cm.sendOpenConfirmation(c);
117 is = c.getStdoutStream();
118 os = c.getStdinStream();
119 int totalSize = 4;
120 int readSoFar = 0;
121
122 while (true) {
123 int len;
124
125 try {
126 len = is.read(buffer, readSoFar, buffer.length - readSoFar);
127 }
128 catch (IOException e) {
129 stopWorking();
130 return;
131 }
132
133 if (len <= 0)
134 break;
135
136 readSoFar += len;
137
138 if (readSoFar >= 4) {
139 TypesReader tr = new TypesReader(buffer, 0, 4);
140 totalSize = tr.readUINT32() + 4;
141 }
142
143 if (totalSize == readSoFar) {
144 TypesReader tr = new TypesReader(buffer, 4, readSoFar - 4);
145 int messageType = tr.readByte();
146
147 switch (messageType) {
148 case SSH2_AGENTC_REQUEST_IDENTITIES:
149 sendIdentities();
150 break;
151
152 case SSH2_AGENTC_ADD_IDENTITY:
153 addIdentity(tr, false);
154 break;
155
156 case SSH2_AGENTC_ADD_ID_CONSTRAINED:
157 addIdentity(tr, true);
158 break;
159
160 case SSH2_AGENTC_REMOVE_IDENTITY:
161 removeIdentity(tr);
162 break;
163
164 case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
165 removeAllIdentities(tr);
166 break;
167
168 case SSH2_AGENTC_SIGN_REQUEST:
169 processSignRequest(tr);
170 break;
171
172 case SSH_AGENTC_LOCK:
173 processLockRequest(tr);
174 break;
175
176 case SSH_AGENTC_UNLOCK:
177 processUnlockRequest(tr);
178 break;
179
180 default:
181 os.write(SSH_AGENT_FAILURE);
182 break;
183 }
184
185 readSoFar = 0;
186 }
187 }
188
189 c.cm.closeChannel(c, "EOF on both streams reached.", true);
190 }
191 catch (IOException e) {
192 log.debug("IOException in agent forwarder: " + e.getMessage());
193
194 try {
195 is.close();
196 }
197 catch (IOException e1) {
198 }
199
200 try {
201 os.close();
202 }
203 catch (IOException e2) {
204 }
205
206 try {
207 c.cm.closeChannel(c, "IOException in agent forwarder (" + e.getMessage() + ")", true);
208 }
209 catch (IOException e3) {
210 }
211 }
212 }
213
214 public void stopWorking() {
215 try {
216 /* This will lead to an IOException in the is.read() call */
217 is.close();
218 }
219 catch (IOException e) {
220 }
221 }
222
223 /**
224 * @return whether the agent is locked
225 */
226 private boolean failWhenLocked() throws IOException {
227 if (authAgent.isAgentLocked()) {
228 os.write(SSH_AGENT_FAILURE);
229 return true;
230 }
231 else
232 return false;
233 }
234
235 private void sendIdentities() throws IOException {
236 Map<String, byte[]> keys = null;
237 TypesWriter tw = new TypesWriter();
238 tw.writeByte(SSH2_AGENT_IDENTITIES_ANSWER);
239 int numKeys = 0;
240
241 if (!authAgent.isAgentLocked())
242 keys = authAgent.retrieveIdentities();
243
244 if (keys != null)
245 numKeys = keys.size();
246
247 tw.writeUINT32(numKeys);
248
249 if (keys != null) {
250 for (Entry<String, byte[]> entry : keys.entrySet()) {
251 byte[] keyBytes = entry.getValue();
252 tw.writeString(keyBytes, 0, keyBytes.length);
253 tw.writeString(entry.getKey());
254 }
255 }
256
257 sendPacket(tw.getBytes());
258 }
259
260 /**
261 * @param tr
262 */
263 private void addIdentity(TypesReader tr, boolean checkConstraints) {
264 try {
265 if (failWhenLocked())
266 return;
267
268 String type = tr.readString();
269 String comment;
270 String keyType;
271 KeySpec pubSpec;
272 KeySpec privSpec;
273
274 if (type.equals("ssh-rsa")) {
275 keyType = "RSA";
276 BigInteger n = tr.readMPINT();
277 BigInteger e = tr.readMPINT();
278 BigInteger d = tr.readMPINT();
279 BigInteger iqmp = tr.readMPINT();
280 BigInteger p = tr.readMPINT();
281 BigInteger q = tr.readMPINT();
282 comment = tr.readString();
283 // Derive the extra values Java needs.
284 BigInteger dmp1 = d.mod(p.subtract(BigInteger.ONE));
285 BigInteger dmq1 = d.mod(q.subtract(BigInteger.ONE));
286 pubSpec = new RSAPublicKeySpec(n, e);
287 privSpec = new RSAPrivateCrtKeySpec(n, e, d, p, q, dmp1, dmq1, iqmp);
288 }
289 else if (type.equals("ssh-dss")) {
290 keyType = "DSA";
291 BigInteger p = tr.readMPINT();
292 BigInteger q = tr.readMPINT();
293 BigInteger g = tr.readMPINT();
294 BigInteger y = tr.readMPINT();
295 BigInteger x = tr.readMPINT();
296 comment = tr.readString();
297 pubSpec = new DSAPublicKeySpec(y, p, q, g);
298 privSpec = new DSAPrivateKeySpec(x, p, q, g);
299 }
300 else if (type.equals("ecdsa-sha2-nistp256")) {
301 keyType = "EC";
302 String curveName = tr.readString();
303 byte[] groupBytes = tr.readByteString();
304 BigInteger exponent = tr.readMPINT();
305 comment = tr.readString();
306
307 if (!"nistp256".equals(curveName)) {
308 log.debug("Invalid curve name for ecdsa-sha2-nistp256: " + curveName);
309 os.write(SSH_AGENT_FAILURE);
310 return;
311 }
312
313 ECParameterSpec nistp256 = ECDSASHA2Verify.EllipticCurves.nistp256;
314 ECPoint group = ECDSASHA2Verify.decodeECPoint(groupBytes, nistp256.getCurve());
315
316 if (group == null) {
317 log.debug("No groupfor ecdsa-sha2-nistp256: ");
318 os.write(SSH_AGENT_FAILURE);
319 return;
320 }
321
322 pubSpec = new ECPublicKeySpec(group, nistp256);
323 privSpec = new ECPrivateKeySpec(exponent, nistp256);
324 }
325 else {
326 log.debug("Unknown key type: " + type);
327 os.write(SSH_AGENT_FAILURE);
328 return;
329 }
330
331 PublicKey pubKey;
332 PrivateKey privKey;
333
334 try {
335 KeyFactory kf = KeyFactory.getInstance(keyType);
336 pubKey = kf.generatePublic(pubSpec);
337 privKey = kf.generatePrivate(privSpec);
338 }
339 catch (NoSuchAlgorithmException ex) {
340 // TODO: log error
341 os.write(SSH_AGENT_FAILURE);
342 return;
343 }
344 catch (InvalidKeySpecException ex) {
345 // TODO: log error
346 os.write(SSH_AGENT_FAILURE);
347 return;
348 }
349
350 KeyPair pair = new KeyPair(pubKey, privKey);
351 boolean confirmUse = false;
352 int lifetime = 0;
353
354 if (checkConstraints) {
355 while (tr.remain() > 0) {
356 int constraint = tr.readByte();
357
358 if (constraint == SSH_AGENT_CONSTRAIN_CONFIRM)
359 confirmUse = true;
360 else if (constraint == SSH_AGENT_CONSTRAIN_LIFETIME)
361 lifetime = tr.readUINT32();
362 else {
363 // Unknown constraint. Bail.
364 os.write(SSH_AGENT_FAILURE);
365 return;
366 }
367 }
368 }
369
370 if (authAgent.addIdentity(pair, comment, confirmUse, lifetime))
371 os.write(SSH_AGENT_SUCCESS);
372 else
373 os.write(SSH_AGENT_FAILURE);
374 }
375 catch (IOException e) {
376 try {
377 os.write(SSH_AGENT_FAILURE);
378 }
379 catch (IOException e1) {
380 }
381 }
382 }
383
384 /**
385 * @param tr
386 */
387 private void removeIdentity(TypesReader tr) {
388 try {
389 if (failWhenLocked())
390 return;
391
392 byte[] publicKey = tr.readByteString();
393
394 if (authAgent.removeIdentity(publicKey))
395 os.write(SSH_AGENT_SUCCESS);
396 else
397 os.write(SSH_AGENT_FAILURE);
398 }
399 catch (IOException e) {
400 try {
401 os.write(SSH_AGENT_FAILURE);
402 }
403 catch (IOException e1) {
404 }
405 }
406 }
407
408 /**
409 * @param tr
410 */
411 private void removeAllIdentities(TypesReader tr) {
412 try {
413 if (failWhenLocked())
414 return;
415
416 if (authAgent.removeAllIdentities())
417 os.write(SSH_AGENT_SUCCESS);
418 else
419 os.write(SSH_AGENT_FAILURE);
420 }
421 catch (IOException e) {
422 try {
423 os.write(SSH_AGENT_FAILURE);
424 }
425 catch (IOException e1) {
426 }
427 }
428 }
429
430 private void processSignRequest(TypesReader tr) {
431 try {
432 if (failWhenLocked())
433 return;
434
435 byte[] publicKeyBytes = tr.readByteString();
436 byte[] challenge = tr.readByteString();
437 int flags = tr.readUINT32();
438
439 if (flags != 0) {
440 // We don't understand any flags; abort!
441 os.write(SSH_AGENT_FAILURE);
442 return;
443 }
444
445 KeyPair pair = authAgent.getKeyPair(publicKeyBytes);
446
447 if (pair == null) {
448 os.write(SSH_AGENT_FAILURE);
449 return;
450 }
451
452 byte[] response;
453 PrivateKey privKey = pair.getPrivate();
454
455 if (privKey instanceof RSAPrivateKey) {
456 byte[] signature = RSASHA1Verify.generateSignature(challenge,
457 (RSAPrivateKey) privKey);
458 response = RSASHA1Verify.encodeSSHRSASignature(signature);
459 }
460 else if (privKey instanceof DSAPrivateKey) {
461 byte[] signature = DSASHA1Verify.generateSignature(challenge,
462 (DSAPrivateKey) privKey, new SecureRandomFix());
463 response = DSASHA1Verify.encodeSSHDSASignature(signature);
464 }
465 else if (privKey instanceof ECPrivateKey) {
466 ECPrivateKey pk = (ECPrivateKey) privKey;
467 byte[] signature = ECDSASHA2Verify.generateSignature(challenge, pk);
468 response = ECDSASHA2Verify.encodeSSHECDSASignature(signature, pk.getParams());
469 }
470 else {
471 os.write(SSH_AGENT_FAILURE);
472 return;
473 }
474
475 TypesWriter tw = new TypesWriter();
476 tw.writeByte(SSH2_AGENT_SIGN_RESPONSE);
477 tw.writeString(response, 0, response.length);
478 sendPacket(tw.getBytes());
479 }
480 catch (IOException e) {
481 try {
482 os.write(SSH_AGENT_FAILURE);
483 }
484 catch (IOException e1) {
485 }
486 }
487 }
488
489 /**
490 * @param tr
491 */
492 private void processLockRequest(TypesReader tr) {
493 try {
494 if (failWhenLocked())
495 return;
496
497 String lockPassphrase = tr.readString();
498
499 if (!authAgent.setAgentLock(lockPassphrase)) {
500 os.write(SSH_AGENT_FAILURE);
501 return;
502 }
503 else
504 os.write(SSH_AGENT_SUCCESS);
505 }
506 catch (IOException e) {
507 try {
508 os.write(SSH_AGENT_FAILURE);
509 }
510 catch (IOException e1) {
511 }
512 }
513 }
514
515 /**
516 * @param tr
517 */
518 private void processUnlockRequest(TypesReader tr) {
519 try {
520 String unlockPassphrase = tr.readString();
521
522 if (authAgent.requestAgentUnlock(unlockPassphrase))
523 os.write(SSH_AGENT_SUCCESS);
524 else
525 os.write(SSH_AGENT_FAILURE);
526 }
527 catch (IOException e) {
528 try {
529 os.write(SSH_AGENT_FAILURE);
530 }
531 catch (IOException e1) {
532 }
533 }
534 }
535
536 /**
537 * @param tw
538 * @throws IOException
539 */
540 private void sendPacket(byte[] message) throws IOException {
541 TypesWriter packet = new TypesWriter();
542 packet.writeUINT32(message.length);
543 packet.writeBytes(message);
544 os.write(packet.getBytes());
545 }
546 }