1package eu.siacs.conversations.crypto.axolotl;
2
3import android.support.annotation.NonNull;
4import android.support.annotation.Nullable;
5import android.util.Log;
6
7import org.whispersystems.libaxolotl.AxolotlAddress;
8import org.whispersystems.libaxolotl.DuplicateMessageException;
9import org.whispersystems.libaxolotl.IdentityKey;
10import org.whispersystems.libaxolotl.InvalidKeyException;
11import org.whispersystems.libaxolotl.InvalidKeyIdException;
12import org.whispersystems.libaxolotl.InvalidMessageException;
13import org.whispersystems.libaxolotl.InvalidVersionException;
14import org.whispersystems.libaxolotl.LegacyMessageException;
15import org.whispersystems.libaxolotl.NoSessionException;
16import org.whispersystems.libaxolotl.SessionCipher;
17import org.whispersystems.libaxolotl.UntrustedIdentityException;
18import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
19import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
20import org.whispersystems.libaxolotl.protocol.WhisperMessage;
21
22import eu.siacs.conversations.Config;
23import eu.siacs.conversations.entities.Account;
24
25public class XmppAxolotlSession implements Comparable<XmppAxolotlSession> {
26 private final SessionCipher cipher;
27 private final SQLiteAxolotlStore sqLiteAxolotlStore;
28 private final AxolotlAddress remoteAddress;
29 private final Account account;
30 private IdentityKey identityKey;
31 private Integer preKeyId = null;
32 private boolean fresh = true;
33
34 public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress, IdentityKey identityKey) {
35 this(account, store, remoteAddress);
36 this.identityKey = identityKey;
37 }
38
39 public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress) {
40 this.cipher = new SessionCipher(store, remoteAddress);
41 this.remoteAddress = remoteAddress;
42 this.sqLiteAxolotlStore = store;
43 this.account = account;
44 }
45
46 public Integer getPreKeyId() {
47 return preKeyId;
48 }
49
50 public void resetPreKeyId() {
51
52 preKeyId = null;
53 }
54
55 public String getFingerprint() {
56 return identityKey == null ? null : identityKey.getFingerprint().replaceAll("\\s", "");
57 }
58
59 public IdentityKey getIdentityKey() {
60 return identityKey;
61 }
62
63 public AxolotlAddress getRemoteAddress() {
64 return remoteAddress;
65 }
66
67 public boolean isFresh() {
68 return fresh;
69 }
70
71 public void setNotFresh() {
72 this.fresh = false;
73 }
74
75 protected void setTrust(FingerprintStatus status) {
76 sqLiteAxolotlStore.setFingerprintStatus(getFingerprint(), status);
77 }
78
79 public FingerprintStatus getTrust() {
80 FingerprintStatus status = sqLiteAxolotlStore.getFingerprintStatus(getFingerprint());
81 return (status == null) ? FingerprintStatus.createActiveUndecided() : status;
82 }
83
84 @Nullable
85 public byte[] processReceiving(AxolotlKey encryptedKey) throws CryptoFailedException {
86 byte[] plaintext = null;
87 FingerprintStatus status = getTrust();
88 if (!status.isCompromised()) {
89 try {
90 try {
91 PreKeyWhisperMessage message = new PreKeyWhisperMessage(encryptedKey.key);
92 if (!message.getPreKeyId().isPresent()) {
93 throw new CryptoFailedException("PreKeyWhisperMessage did not contain a PreKeyId");
94 }
95 Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "PreKeyWhisperMessage received, new session ID:" + message.getSignedPreKeyId() + "/" + message.getPreKeyId());
96 IdentityKey msgIdentityKey = message.getIdentityKey();
97 if (this.identityKey != null && !this.identityKey.equals(msgIdentityKey)) {
98 Log.e(Config.LOGTAG, AxolotlService.getLogprefix(account) + "Had session with fingerprint " + this.getFingerprint() + ", received message with fingerprint " + msgIdentityKey.getFingerprint());
99 } else {
100 this.identityKey = msgIdentityKey;
101 plaintext = cipher.decrypt(message);
102 preKeyId = message.getPreKeyId().get();
103 }
104 } catch (InvalidMessageException | InvalidVersionException e) {
105 Log.i(Config.LOGTAG, AxolotlService.getLogprefix(account) + "WhisperMessage received");
106 WhisperMessage message = new WhisperMessage(encryptedKey.key);
107 plaintext = cipher.decrypt(message);
108 } catch (InvalidKeyException | InvalidKeyIdException | UntrustedIdentityException e) {
109 throw new CryptoFailedException("Error decrypting axolotl header, \" + e.getClass().getName() + \": \" + e.getMessage()");
110 }
111 } catch (LegacyMessageException | InvalidMessageException | DuplicateMessageException | NoSessionException e) {
112 throw new CryptoFailedException("Error decrypting axolotl header, \" + e.getClass().getName() + \": \" + e.getMessage()");
113 }
114 if (plaintext==null) {
115 throw new CryptoFailedException("plaintext unexpectedly null");
116 }
117 if (!status.isActive()) {
118 setTrust(status.toActive());
119 }
120 } else {
121 throw new CryptoFailedException("not encrypting omemo message from fingerprint "+getFingerprint()+" because it was marked as compromised");
122 }
123 return plaintext;
124 }
125
126 @Nullable
127 public AxolotlKey processSending(@NonNull byte[] outgoingMessage) {
128 FingerprintStatus status = getTrust();
129 if (status.isTrustedAndActive()) {
130 CiphertextMessage ciphertextMessage = cipher.encrypt(outgoingMessage);
131 return new AxolotlKey(ciphertextMessage.serialize(),ciphertextMessage.getType() == CiphertextMessage.PREKEY_TYPE);
132 } else {
133 return null;
134 }
135 }
136
137 public Account getAccount() {
138 return account;
139 }
140
141 @Override
142 public int compareTo(XmppAxolotlSession o) {
143 return getTrust().compareTo(o.getTrust());
144 }
145
146 public static class AxolotlKey {
147
148
149 public final byte[] key;
150 public final boolean prekey;
151
152 public AxolotlKey(byte[] key, boolean prekey) {
153 this.key = key;
154 this.prekey = prekey;
155 }
156 }
157}