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