001/**
002 *
003 * Copyright 2017 Paul Schaub
004 *
005 * This file is part of smack-omemo-signal.
006 *
007 * smack-omemo-signal is free software; you can redistribute it and/or modify
008 * it under the terms of the GNU General Public License as published by
009 * the Free Software Foundation; either version 3 of the License, or
010 * (at your option) any later version.
011 *
012 * This program is distributed in the hope that it will be useful,
013 * but WITHOUT ANY WARRANTY; without even the implied warranty of
014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
015 * GNU General Public License for more details.
016 *
017 * You should have received a copy of the GNU General Public License
018 * along with this program; if not, write to the Free Software Foundation,
019 * Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
020 */
021package org.jivesoftware.smackx.omemo.signal;
022
023import java.io.IOException;
024import java.util.List;
025import java.util.TreeMap;
026
027import org.jivesoftware.smackx.omemo.element.OmemoBundleElement;
028import org.jivesoftware.smackx.omemo.exceptions.CorruptedOmemoKeyException;
029import org.jivesoftware.smackx.omemo.internal.OmemoDevice;
030import org.jivesoftware.smackx.omemo.trust.OmemoFingerprint;
031import org.jivesoftware.smackx.omemo.util.OmemoKeyUtil;
032
033import org.whispersystems.libsignal.IdentityKey;
034import org.whispersystems.libsignal.IdentityKeyPair;
035import org.whispersystems.libsignal.InvalidKeyException;
036import org.whispersystems.libsignal.ecc.Curve;
037import org.whispersystems.libsignal.ecc.ECPublicKey;
038import org.whispersystems.libsignal.state.PreKeyBundle;
039import org.whispersystems.libsignal.state.PreKeyRecord;
040import org.whispersystems.libsignal.state.SessionRecord;
041import org.whispersystems.libsignal.state.SignedPreKeyRecord;
042import org.whispersystems.libsignal.util.KeyHelper;
043
044/**
045 * Concrete implementation of the KeyUtil for an implementation using the Signal library.
046 *
047 * @author Paul Schaub
048 */
049public class SignalOmemoKeyUtil extends OmemoKeyUtil<IdentityKeyPair, IdentityKey, PreKeyRecord, SignedPreKeyRecord,
050        SessionRecord, ECPublicKey, PreKeyBundle> {
051
052    @Override
053    public IdentityKeyPair generateOmemoIdentityKeyPair() {
054        return KeyHelper.generateIdentityKeyPair();
055    }
056
057    @Override
058    public TreeMap<Integer, PreKeyRecord> generateOmemoPreKeys(int currentPreKeyId, int count) {
059        List<PreKeyRecord> preKeyRecords = KeyHelper.generatePreKeys(currentPreKeyId, count);
060        TreeMap<Integer, PreKeyRecord> map = new TreeMap<>();
061        for (PreKeyRecord p : preKeyRecords) {
062            map.put(p.getId(), p);
063        }
064        return map;
065    }
066
067    @Override
068    public SignedPreKeyRecord generateOmemoSignedPreKey(IdentityKeyPair identityKeyPair, int currentPreKeyId)
069            throws CorruptedOmemoKeyException {
070        try {
071            return KeyHelper.generateSignedPreKey(identityKeyPair, currentPreKeyId);
072        } catch (InvalidKeyException e) {
073            throw new CorruptedOmemoKeyException(e);
074        }
075    }
076
077    @Override
078    public SignedPreKeyRecord signedPreKeyFromBytes(byte[] data) throws IOException {
079        if (data == null) return null;
080        return new SignedPreKeyRecord(data);
081    }
082
083    @Override
084    public byte[] signedPreKeyToBytes(SignedPreKeyRecord signedPreKeyRecord) {
085        return signedPreKeyRecord.serialize();
086    }
087
088    @Override
089    public SessionRecord rawSessionFromBytes(byte[] data) throws IOException {
090        if (data == null) return null;
091        return new SessionRecord(data);
092    }
093
094    @Override
095    public byte[] rawSessionToBytes(SessionRecord session) {
096        return session.serialize();
097    }
098
099    @Override
100    public IdentityKeyPair identityKeyPairFromBytes(byte[] data) throws CorruptedOmemoKeyException {
101        if (data == null) return null;
102        try {
103            return new IdentityKeyPair(data);
104        } catch (InvalidKeyException e) {
105            throw new CorruptedOmemoKeyException(e);
106        }
107    }
108
109    @Override
110    public IdentityKey identityKeyFromBytes(byte[] data) throws CorruptedOmemoKeyException {
111        if (data == null) return null;
112        try {
113            return new IdentityKey(data, 0);
114        } catch (InvalidKeyException e) {
115            throw new CorruptedOmemoKeyException(e);
116        }
117    }
118
119    @Override
120    public ECPublicKey ellipticCurvePublicKeyFromBytes(byte[] data) throws CorruptedOmemoKeyException {
121        if (data == null) return null;
122        try {
123            return Curve.decodePoint(data, 0);
124        } catch (InvalidKeyException e) {
125            throw new CorruptedOmemoKeyException(e);
126        }
127    }
128
129    @Override
130    public byte[] preKeyToBytes(PreKeyRecord preKeyRecord) {
131        return preKeyRecord.serialize();
132    }
133
134    @Override
135    public PreKeyRecord preKeyFromBytes(byte[] bytes) throws IOException {
136        if (bytes == null) return null;
137        return new PreKeyRecord(bytes);
138    }
139
140    @Override
141    public PreKeyBundle bundleFromOmemoBundle(OmemoBundleElement bundle, OmemoDevice contact, int preKeyId)
142            throws CorruptedOmemoKeyException {
143        return new PreKeyBundle(0,
144                contact.getDeviceId(),
145                preKeyId,
146                BUNDLE.preKeyPublic(bundle, preKeyId),
147                BUNDLE.signedPreKeyId(bundle),
148                BUNDLE.signedPreKeyPublic(bundle),
149                BUNDLE.signedPreKeySignature(bundle),
150                BUNDLE.identityKey(bundle));
151    }
152
153    @Override
154    public byte[] signedPreKeySignatureFromKey(SignedPreKeyRecord signedPreKey) {
155        return signedPreKey.getSignature();
156    }
157
158    @Override
159    public int signedPreKeyIdFromKey(SignedPreKeyRecord signedPreKey) {
160        return signedPreKey.getId();
161    }
162
163    @Override
164    public byte[] identityKeyPairToBytes(IdentityKeyPair identityKeyPair) {
165        return identityKeyPair.serialize();
166    }
167
168    @Override
169    public IdentityKey identityKeyFromPair(IdentityKeyPair identityKeyPair) {
170        return identityKeyPair.getPublicKey();
171    }
172
173    @Override
174    public byte[] identityKeyForBundle(IdentityKey identityKey) {
175        return identityKey.getPublicKey().serialize();
176    }
177
178    @Override
179    public byte[] identityKeyToBytes(IdentityKey identityKey) {
180        return identityKey.serialize();
181    }
182
183    @Override
184    public byte[] preKeyPublicKeyForBundle(ECPublicKey preKey) {
185        return preKey.serialize();
186    }
187
188    @Override
189    public byte[] preKeyForBundle(PreKeyRecord preKeyRecord) {
190        return preKeyRecord.getKeyPair().getPublicKey().serialize();
191    }
192
193    @Override
194    public byte[] signedPreKeyPublicForBundle(SignedPreKeyRecord signedPreKey) {
195        return signedPreKey.getKeyPair().getPublicKey().serialize();
196    }
197
198    @Override
199    public OmemoFingerprint getFingerprintOfIdentityKey(IdentityKey identityKey) {
200        if (identityKey == null) {
201            return null;
202        }
203
204        String fp = identityKey.getFingerprint();
205        // Cut "(byte)0x" prefixes, remove spaces and commas, cut first two digits.
206        fp = fp.replace("(byte)0x", "").replace(",", "")
207                .replace(" ", "").substring(2);
208        return new OmemoFingerprint(fp);
209    }
210
211    @Override
212    public OmemoFingerprint getFingerprintOfIdentityKeyPair(IdentityKeyPair identityKeyPair) {
213        if (identityKeyPair == null) {
214            return null;
215        }
216        return getFingerprintOfIdentityKey(identityKeyPair.getPublicKey());
217    }
218}