1package de.gultsch.chat.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 de.gultsch.chat.entities.Account;
21import de.gultsch.chat.persistance.DatabaseBackend;
22import de.gultsch.chat.xml.Element;
23import de.gultsch.chat.xmpp.MessagePacket;
24
25import net.java.otr4j.OtrEngineHost;
26import net.java.otr4j.OtrException;
27import net.java.otr4j.OtrPolicy;
28import net.java.otr4j.OtrPolicyImpl;
29import net.java.otr4j.session.InstanceTag;
30import net.java.otr4j.session.SessionID;
31
32public class OtrEngine implements OtrEngineHost {
33
34 private static final String LOGTAG = "xmppService";
35
36 private Account account;
37 private OtrPolicy otrPolicy;
38 private KeyPair keyPair;
39 private Context context;
40
41 public OtrEngine(Context context, Account account) {
42 this.account = account;
43 this.otrPolicy = new OtrPolicyImpl();
44 this.otrPolicy.setAllowV1(false);
45 this.otrPolicy.setAllowV2(true);
46 this.otrPolicy.setAllowV3(true);
47 this.keyPair = loadKey(account.getKeys());
48 }
49
50 private KeyPair loadKey(JSONObject keys) {
51 if (keys == null) {
52 return null;
53 }
54 try {
55 BigInteger x = new BigInteger(keys.getString("otr_x"),16);
56 BigInteger y = new BigInteger(keys.getString("otr_y"),16);
57 BigInteger p = new BigInteger(keys.getString("otr_p"),16);
58 BigInteger q = new BigInteger(keys.getString("otr_q"),16);
59 BigInteger g = new BigInteger(keys.getString("otr_g"),16);
60 KeyFactory keyFactory = KeyFactory.getInstance("DSA");
61 DSAPublicKeySpec pubKeySpec = new DSAPublicKeySpec(y, p, q, g);
62 DSAPrivateKeySpec privateKeySpec = new DSAPrivateKeySpec(x, p, q, g);
63 PublicKey publicKey = keyFactory.generatePublic(pubKeySpec);
64 PrivateKey privateKey = keyFactory.generatePrivate(privateKeySpec);
65 return new KeyPair(publicKey, privateKey);
66 } catch (JSONException e) {
67 // TODO Auto-generated catch block
68 e.printStackTrace();
69 } catch (NoSuchAlgorithmException e) {
70 // TODO Auto-generated catch block
71 e.printStackTrace();
72 } catch (InvalidKeySpecException e) {
73 // TODO Auto-generated catch block
74 e.printStackTrace();
75 }
76 return null;
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(privateKey, DSAPrivateKeySpec.class);
86 DSAPublicKeySpec publicKeySpec = keyFactory.getKeySpec(publicKey, 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 // TODO Auto-generated method stub
110
111 }
112
113 @Override
114 public String getFallbackMessage(SessionID arg0) {
115 // TODO Auto-generated method stub
116 return null;
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 return this.keyPair.getPublic();
127 }
128
129 @Override
130 public KeyPair getLocalKeyPair(SessionID arg0) throws OtrException {
131 if (this.keyPair==null) {
132 KeyPairGenerator kg;
133 try {
134 kg = KeyPairGenerator.getInstance("DSA");
135 this.keyPair = kg.genKeyPair();
136 this.saveKey();
137 DatabaseBackend.getInstance(context).updateAccount(account);
138 } catch (NoSuchAlgorithmException e) {
139 Log.d(LOGTAG,"error generating key pair "+e.getMessage());
140 }
141 }
142 return this.keyPair;
143 }
144
145 @Override
146 public String getReplyForUnreadableMessage(SessionID arg0) {
147 // TODO Auto-generated method stub
148 return null;
149 }
150
151 @Override
152 public OtrPolicy getSessionPolicy(SessionID arg0) {
153 return otrPolicy;
154 }
155
156 @Override
157 public void injectMessage(SessionID session, String body) throws OtrException {
158 MessagePacket packet = new MessagePacket();
159 packet.setFrom(account.getFullJid()); //sender
160 packet.setTo(session.getAccountID()+"/"+session.getUserID()); //reciepient
161 packet.setBody(body);
162 Element privateTag = new Element("private");
163 privateTag.setAttribute("xmlns","urn:xmpp:carbons:2");
164 packet.addChild(privateTag);
165 packet.setType(MessagePacket.TYPE_CHAT);
166 account.getXmppConnection().sendMessagePacket(packet);
167 }
168
169 @Override
170 public void messageFromAnotherInstanceReceived(SessionID arg0) {
171 // TODO Auto-generated method stub
172
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 // TODO Auto-generated method stub
204
205 }
206
207 @Override
208 public void unencryptedMessageReceived(SessionID arg0, String arg1)
209 throws OtrException {
210 // TODO Auto-generated method stub
211
212 }
213
214 @Override
215 public void unreadableMessageReceived(SessionID arg0) throws OtrException {
216 // TODO Auto-generated method stub
217
218 }
219
220 @Override
221 public void unverify(SessionID arg0, String arg1) {
222 // TODO Auto-generated method stub
223
224 }
225
226 @Override
227 public void verify(SessionID arg0, String arg1, boolean arg2) {
228 // TODO Auto-generated method stub
229
230 }
231
232}