aboutsummaryrefslogtreecommitdiffstats
path: root/src/main/java/de/thedevstack/conversationsplus/crypto/OtrService.java
blob: 34023d9f49b7478e5414d3f220927396aaa8a7d0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
package de.thedevstack.conversationsplus.crypto;

import net.java.otr4j.OtrEngineHost;
import net.java.otr4j.OtrException;
import net.java.otr4j.OtrPolicy;
import net.java.otr4j.OtrPolicyImpl;
import net.java.otr4j.crypto.OtrCryptoEngineImpl;
import net.java.otr4j.crypto.OtrCryptoException;
import net.java.otr4j.session.FragmenterInstructions;
import net.java.otr4j.session.InstanceTag;
import net.java.otr4j.session.SessionID;

import org.json.JSONException;
import org.json.JSONObject;

import java.math.BigInteger;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.spec.DSAPrivateKeySpec;
import java.security.spec.DSAPublicKeySpec;
import java.security.spec.InvalidKeySpecException;

import de.thedevstack.android.logcat.Logging;
import de.thedevstack.conversationsplus.ConversationsPlusPreferences;
import de.thedevstack.conversationsplus.Config;
import de.thedevstack.conversationsplus.entities.Account;
import de.thedevstack.conversationsplus.entities.Conversation;
import de.thedevstack.conversationsplus.generator.MessageGenerator;
import de.thedevstack.conversationsplus.services.XmppConnectionService;
import de.thedevstack.conversationsplus.xmpp.chatstate.ChatState;
import de.thedevstack.conversationsplus.xmpp.jid.InvalidJidException;
import de.thedevstack.conversationsplus.xmpp.jid.Jid;
import de.thedevstack.conversationsplus.xmpp.stanzas.MessagePacket;

public class OtrService extends OtrCryptoEngineImpl implements OtrEngineHost {

	private Account account;
	private OtrPolicy otrPolicy;
	private KeyPair keyPair;
	private XmppConnectionService mXmppConnectionService;

	public OtrService(XmppConnectionService service, Account account) {
		this.account = account;
		this.otrPolicy = new OtrPolicyImpl();
		this.otrPolicy.setAllowV1(false);
		this.otrPolicy.setAllowV2(true);
		this.otrPolicy.setAllowV3(true);
		this.keyPair = loadKey(account.getKeys());
		this.mXmppConnectionService = service;
	}

	private KeyPair loadKey(JSONObject keys) {
		if (keys == null) {
			return null;
		}
		try {
			BigInteger x = new BigInteger(keys.getString("otr_x"), 16);
			BigInteger y = new BigInteger(keys.getString("otr_y"), 16);
			BigInteger p = new BigInteger(keys.getString("otr_p"), 16);
			BigInteger q = new BigInteger(keys.getString("otr_q"), 16);
			BigInteger g = new BigInteger(keys.getString("otr_g"), 16);
			KeyFactory keyFactory = KeyFactory.getInstance("DSA");
			DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
			DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
			PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
			PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
			return new KeyPair(publicKey, privateKey);
		} catch (JSONException e) {
			return null;
		} catch (NoSuchAlgorithmException e) {
			return null;
		} catch (InvalidKeySpecException e) {
			return null;
		}
	}

	private void saveKey() {
		PublicKey publicKey = keyPair.getPublic();
		PrivateKey privateKey = keyPair.getPrivate();
		KeyFactory keyFactory;
		try {
			keyFactory = KeyFactory.getInstance("DSA");
			DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(
					privateKey, DSAPrivateKeySpec.class);
			DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey,
					DSAPublicKeySpec.class);
			this.account.setKey("otr_x", privateKeySpec.getX().toString(16));
			this.account.setKey("otr_g", privateKeySpec.getG().toString(16));
			this.account.setKey("otr_p", privateKeySpec.getP().toString(16));
			this.account.setKey("otr_q", privateKeySpec.getQ().toString(16));
			this.account.setKey("otr_y", publicKeySpec.getY().toString(16));
		} catch (final NoSuchAlgorithmException | InvalidKeySpecException e) {
			e.printStackTrace();
		}

    }

	@Override
	public void askForSecret(SessionID id, InstanceTag instanceTag, String question) {
		try {
			final Jid jid = Jid.fromSessionID(id);
			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
			if (conversation!=null) {
				conversation.smp().hint = question;
				conversation.smp().status = Conversation.Smp.STATUS_CONTACT_REQUESTED;
				mXmppConnectionService.updateConversationUi();
			}
		} catch (InvalidJidException e) {
			Logging.d(Config.LOGTAG,account.getJid().toBareJid()+": smp in invalid session "+id.toString());
		}
	}

	@Override
	public void finishedSessionMessage(SessionID arg0, String arg1)
			throws OtrException {

	}

	@Override
	public String getFallbackMessage(SessionID arg0) {
		return "I would like to start a private (OTR encrypted) conversation but your client doesn’t seem to support that";
	}

	@Override
	public byte[] getLocalFingerprintRaw(SessionID arg0) {
		try {
			return getFingerprintRaw(getPublicKey());
		} catch (OtrCryptoException e) {
			return null;
		}
	}

	public PublicKey getPublicKey() {
		if (this.keyPair == null) {
			return null;
		}
		return this.keyPair.getPublic();
	}

	@Override
	public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
		if (this.keyPair == null) {
			KeyPairGenerator kg;
			try {
				kg = KeyPairGenerator.getInstance("DSA");
				this.keyPair = kg.genKeyPair();
				this.saveKey();
				mXmppConnectionService.databaseBackend.updateAccount(account);
			} catch (NoSuchAlgorithmException e) {
				Logging.d(Config.LOGTAG,
						"error generating key pair " + e.getMessage());
			}
		}
		return this.keyPair;
	}

	@Override
	public String getReplyForUnreadableMessage(SessionID arg0) {
		// TODO Auto-generated method stub
		return null;
	}

	@Override
	public OtrPolicy getSessionPolicy(SessionID arg0) {
		return otrPolicy;
	}

	@Override
	public void injectMessage(SessionID session, String body)
			throws OtrException {
		MessagePacket packet = new MessagePacket();
		packet.setFrom(account.getJid());
		if (session.getUserID().isEmpty()) {
			packet.setAttribute("to", session.getAccountID());
		} else {
			packet.setAttribute("to", session.getAccountID() + "/" + session.getUserID());
		}
		packet.setBody(body);
		MessageGenerator.addMessageHints(packet);
		try {
			Jid jid = Jid.fromSessionID(session);
			Conversation conversation = mXmppConnectionService.find(account,jid);
			if (conversation != null && conversation.setOutgoingChatState(Config.DEFAULT_CHATSTATE)) {
				if (ConversationsPlusPreferences.chatStates()) {
					packet.addChild(ChatState.toElement(conversation.getOutgoingChatState()));
				}
			}
		} catch (final InvalidJidException ignored) {

		}

		packet.setType(MessagePacket.TYPE_CHAT);
		account.getXmppConnection().sendMessagePacket(packet);
	}

	@Override
	public void messageFromAnotherInstanceReceived(SessionID session) {
		sendOtrErrorMessage(session, "Message from another OTR-instance received");
	}

	@Override
	public void multipleInstancesDetected(SessionID arg0) {
		// TODO Auto-generated method stub

	}

	@Override
	public void requireEncryptedMessage(SessionID arg0, String arg1)
			throws OtrException {
		// TODO Auto-generated method stub

	}

	@Override
	public void showError(SessionID arg0, String arg1) throws OtrException {
		Logging.d(Config.LOGTAG,"show error");
	}

	@Override
	public void smpAborted(SessionID id) throws OtrException {
		setSmpStatus(id, Conversation.Smp.STATUS_NONE);
	}

	private void setSmpStatus(SessionID id, int status) {
		try {
			final Jid jid = Jid.fromSessionID(id);
			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
			if (conversation!=null) {
				conversation.smp().status = status;
				mXmppConnectionService.updateConversationUi();
			}
		} catch (final InvalidJidException ignored) {

		}
	}

	@Override
	public void smpError(SessionID id, int arg1, boolean arg2)
			throws OtrException {
		setSmpStatus(id, Conversation.Smp.STATUS_NONE);
	}

	@Override
	public void unencryptedMessageReceived(SessionID arg0, String arg1)
			throws OtrException {
		throw new OtrException(new Exception("unencrypted message received"));
	}

	@Override
	public void unreadableMessageReceived(SessionID session) throws OtrException {
		Logging.d(Config.LOGTAG,"unreadable message received");
		// Hier update des contents fuer FS#96
		sendOtrErrorMessage(session, "You sent me an unreadable OTR-encrypted message");
	}

	public void sendOtrErrorMessage(SessionID session, String errorText) {
		try {
			Jid jid = Jid.fromSessionID(session);
			Conversation conversation = mXmppConnectionService.find(account, jid);
			String id = conversation == null ? null : conversation.getLastReceivedOtrMessageId();
			if (id != null) {
				MessagePacket packet = mXmppConnectionService.getMessageGenerator()
						.generateOtrError(jid, id, errorText);
				packet.setFrom(account.getJid());
				mXmppConnectionService.sendMessagePacket(account,packet);
				Logging.d(Config.LOGTAG,packet.toString());
				Logging.d(Config.LOGTAG,account.getJid().toBareJid().toString()
						+": unreadable OTR message in "+conversation.getName());
			}
		} catch (InvalidJidException e) {
			return;
		}
	}

	@Override
	public void unverify(SessionID id, String arg1) {
		setSmpStatus(id, Conversation.Smp.STATUS_FAILED);
	}

	@Override
	public void verify(SessionID id, String fingerprint, boolean approved) {
		Logging.d(Config.LOGTAG,"OtrService.verify("+id.toString()+","+fingerprint+","+String.valueOf(approved)+")");
		try {
			final Jid jid = Jid.fromSessionID(id);
			Conversation conversation = this.mXmppConnectionService.find(this.account,jid);
			if (conversation!=null) {
				if (approved) {
					conversation.getContact().addOtrFingerprint(fingerprint);
				}
				conversation.smp().hint = null;
				conversation.smp().status = Conversation.Smp.STATUS_VERIFIED;
				mXmppConnectionService.updateConversationUi();
				mXmppConnectionService.syncRosterToDisk(conversation.getAccount());
			}
		} catch (final InvalidJidException ignored) {
		}
	}

	@Override
	public FragmenterInstructions getFragmenterInstructions(SessionID sessionID) {
		return null;
	}

}