1package eu.siacs.conversations.crypto;
2
3import java.math.BigInteger;
4import java.security.KeyFactory;
5import java.security.KeyPair;
6import java.security.KeyPairGenerator;
7import java.security.NoSuchAlgorithmException;
8import java.security.PrivateKey;
9import java.security.PublicKey;
10import java.security.spec.DSAPrivateKeySpec;
11import java.security.spec.DSAPublicKeySpec;
12import java.security.spec.InvalidKeySpecException;
13
14import org.json.JSONException;
15import org.json.JSONObject;
16
17import android.content.Context;
18import android.util.Log;
19
20import eu.siacs.conversations.Config;
21import eu.siacs.conversations.entities.Account;
22import eu.siacs.conversations.entities.Conversation;
23import eu.siacs.conversations.entities.Message;
24import eu.siacs.conversations.persistance.DatabaseBackend;
25import eu.siacs.conversations.services.XmppConnectionService;
26import eu.siacs.conversations.xmpp.stanzas.MessagePacket;
27
28import net.java.otr4j.OtrEngineHost;
29import net.java.otr4j.OtrException;
30import net.java.otr4j.OtrPolicy;
31import net.java.otr4j.OtrPolicyImpl;
32import net.java.otr4j.session.InstanceTag;
33import net.java.otr4j.session.SessionID;
34import net.java.otr4j.session.SessionImpl;
35import net.java.otr4j.session.SessionStatus;
36
37public class OtrEngine implements OtrEngineHost {
38
39 private Account account;
40 private OtrPolicy otrPolicy;
41 private KeyPair keyPair;
42 private XmppConnectionService mXmppConnectionService;
43
44 public OtrEngine(XmppConnectionService service, Account account) {
45 this.account = account;
46 this.otrPolicy = new OtrPolicyImpl();
47 this.otrPolicy.setAllowV1(false);
48 this.otrPolicy.setAllowV2(true);
49 this.otrPolicy.setAllowV3(true);
50 this.keyPair = loadKey(account.getKeys());
51 this.mXmppConnectionService = service;
52 }
53
54 private KeyPair loadKey(JSONObject keys) {
55 if (keys == null) {
56 return null;
57 }
58 try {
59 BigInteger x = new BigInteger(keys.getString("otr_x"), 16);
60 BigInteger y = new BigInteger(keys.getString("otr_y"), 16);
61 BigInteger p = new BigInteger(keys.getString("otr_p"), 16);
62 BigInteger q = new BigInteger(keys.getString("otr_q"), 16);
63 BigInteger g = new BigInteger(keys.getString("otr_g"), 16);
64 KeyFactory keyFactory = KeyFactory.getInstance("DSA");
65 DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
66 DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
67 PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
68 PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
69 return new KeyPair(publicKey, privateKey);
70 } catch (JSONException e) {
71 return null;
72 } catch (NoSuchAlgorithmException e) {
73 return null;
74 } catch (InvalidKeySpecException e) {
75 return null;
76 }
77 }
78
79 private void saveKey() {
80 PublicKey publicKey = keyPair.getPublic();
81 PrivateKey privateKey = keyPair.getPrivate();
82 KeyFactory keyFactory;
83 try {
84 keyFactory = KeyFactory.getInstance("DSA");
85 DSAPrivateKeySpec privateKeySpec = keyFactory.getKeySpec(
86 privateKey, DSAPrivateKeySpec.class);
87 DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey,
88 DSAPublicKeySpec.class);
89 this.account.setKey("otr_x", privateKeySpec.getX().toString(16));
90 this.account.setKey("otr_g", privateKeySpec.getG().toString(16));
91 this.account.setKey("otr_p", privateKeySpec.getP().toString(16));
92 this.account.setKey("otr_q", privateKeySpec.getQ().toString(16));
93 this.account.setKey("otr_y", publicKeySpec.getY().toString(16));
94 } catch (NoSuchAlgorithmException e) {
95 e.printStackTrace();
96 } catch (InvalidKeySpecException e) {
97 e.printStackTrace();
98 }
99
100 }
101
102 @Override
103 public void askForSecret(SessionID arg0, InstanceTag arg1, String arg2) {
104 // TODO Auto-generated method stub
105
106 }
107
108 @Override
109 public void finishedSessionMessage(SessionID arg0, String arg1)
110 throws OtrException {
111
112 }
113
114 @Override
115 public String getFallbackMessage(SessionID arg0) {
116 return "I would like to start a private (OTR encrypted) conversation but your client doesn’t seem to support that";
117 }
118
119 @Override
120 public byte[] getLocalFingerprintRaw(SessionID arg0) {
121 // TODO Auto-generated method stub
122 return null;
123 }
124
125 public PublicKey getPublicKey() {
126 if (this.keyPair == null) {
127 return null;
128 }
129 return this.keyPair.getPublic();
130 }
131
132 @Override
133 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
134 if (this.keyPair == null) {
135 KeyPairGenerator kg;
136 try {
137 kg = KeyPairGenerator.getInstance("DSA");
138 this.keyPair = kg.genKeyPair();
139 this.saveKey();
140 mXmppConnectionService.databaseBackend.updateAccount(account);
141 } catch (NoSuchAlgorithmException e) {
142 Log.d(Config.LOGTAG,
143 "error generating key pair " + e.getMessage());
144 }
145 }
146 return this.keyPair;
147 }
148
149 @Override
150 public String getReplyForUnreadableMessage(SessionID arg0) {
151 // TODO Auto-generated method stub
152 return null;
153 }
154
155 @Override
156 public OtrPolicy getSessionPolicy(SessionID arg0) {
157 return otrPolicy;
158 }
159
160 @Override
161 public void injectMessage(SessionID session, String body)
162 throws OtrException {
163 MessagePacket packet = new MessagePacket();
164 packet.setFrom(account.getFullJid());
165 if (session.getUserID().isEmpty()) {
166 packet.setTo(session.getAccountID());
167 } else {
168 packet.setTo(session.getAccountID() + "/" + session.getUserID());
169 }
170 packet.setBody(body);
171 packet.addChild("private", "urn:xmpp:carbons:2");
172 packet.addChild("no-copy", "urn:xmpp:hints");
173 packet.setType(MessagePacket.TYPE_CHAT);
174 account.getXmppConnection().sendMessagePacket(packet);
175 }
176
177 @Override
178 public void messageFromAnotherInstanceReceived(SessionID id) {
179 String jid = id.getAccountID();
180 Conversation conversation = mXmppConnectionService
181 .findOrCreateConversation(account, jid, false);
182 Message error = new Message(conversation, null, Message.ENCRYPTION_OTR);
183 conversation.getMessages().add(error);
184 error.setStatus(Message.STATUS_RECEPTION_FAILED);
185 mXmppConnectionService.databaseBackend.createMessage(error);
186 SessionImpl session = conversation.getOtrSession();
187 if (session != null
188 && session.getSessionStatus() != SessionStatus.ENCRYPTED) {
189 try {
190 session.startSession();
191 } catch (OtrException e) {
192 }
193 }
194 }
195
196 @Override
197 public void multipleInstancesDetected(SessionID arg0) {
198 // TODO Auto-generated method stub
199
200 }
201
202 @Override
203 public void requireEncryptedMessage(SessionID arg0, String arg1)
204 throws OtrException {
205 // TODO Auto-generated method stub
206
207 }
208
209 @Override
210 public void showError(SessionID arg0, String arg1) throws OtrException {
211 // TODO Auto-generated method stub
212
213 }
214
215 @Override
216 public void smpAborted(SessionID arg0) throws OtrException {
217 // TODO Auto-generated method stub
218
219 }
220
221 @Override
222 public void smpError(SessionID arg0, int arg1, boolean arg2)
223 throws OtrException {
224 throw new OtrException(new Exception("smp error"));
225 }
226
227 @Override
228 public void unencryptedMessageReceived(SessionID arg0, String arg1)
229 throws OtrException {
230 throw new OtrException(new Exception("unencrypted message received"));
231 }
232
233 @Override
234 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
235 throw new OtrException(new Exception("unreadable message received"));
236 }
237
238 @Override
239 public void unverify(SessionID arg0, String arg1) {
240 // TODO Auto-generated method stub
241
242 }
243
244 @Override
245 public void verify(SessionID arg0, String arg1, boolean arg2) {
246 // TODO Auto-generated method stub
247
248 }
249
250}