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