session-android/src/org/thoughtcrime/securesms/crypto/MasterSecret.java
Moxie Marlinspike a3f1d9cdfd Beginning of libtextsecure refactor.
1) Break out appropriate components.

2) Switch the incoming pipeline from SendReceiveService to
   the JobManager.
2014-11-12 15:21:32 -08:00

120 lines
3.3 KiB
Java

/**
* Copyright (C) 2011 Whisper Systems
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.thoughtcrime.securesms.crypto;
import android.os.Parcel;
import android.os.Parcelable;
import javax.crypto.spec.SecretKeySpec;
import java.util.Arrays;
/**
* When a user first initializes TextSecure, a few secrets
* are generated. These are:
*
* 1) A 128bit symmetric encryption key.
* 2) A 160bit symmetric MAC key.
* 3) An ECC keypair.
*
* The first two, along with the ECC keypair's private key, are
* then encrypted on disk using PBE.
*
* This class represents 1 and 2.
*
* @author Moxie Marlinspike
*/
public class MasterSecret implements Parcelable {
private final SecretKeySpec encryptionKey;
private final SecretKeySpec macKey;
public static final Parcelable.Creator<MasterSecret> CREATOR = new Parcelable.Creator<MasterSecret>() {
@Override
public MasterSecret createFromParcel(Parcel in) {
return new MasterSecret(in);
}
@Override
public MasterSecret[] newArray(int size) {
return new MasterSecret[size];
}
};
public MasterSecret(SecretKeySpec encryptionKey, SecretKeySpec macKey) {
this.encryptionKey = encryptionKey;
this.macKey = macKey;
}
private MasterSecret(Parcel in) {
byte[] encryptionKeyBytes = new byte[in.readInt()];
in.readByteArray(encryptionKeyBytes);
byte[] macKeyBytes = new byte[in.readInt()];
in.readByteArray(macKeyBytes);
this.encryptionKey = new SecretKeySpec(encryptionKeyBytes, "AES");
this.macKey = new SecretKeySpec(macKeyBytes, "HmacSHA1");
// SecretKeySpec does an internal copy in its constructor.
Arrays.fill(encryptionKeyBytes, (byte) 0x00);
Arrays.fill(macKeyBytes, (byte)0x00);
}
public SecretKeySpec getEncryptionKey() {
return this.encryptionKey;
}
public SecretKeySpec getMacKey() {
return this.macKey;
}
@Override
public void writeToParcel(Parcel out, int flags) {
out.writeInt(encryptionKey.getEncoded().length);
out.writeByteArray(encryptionKey.getEncoded());
out.writeInt(macKey.getEncoded().length);
out.writeByteArray(macKey.getEncoded());
}
@Override
public int describeContents() {
return 0;
}
public MasterSecret parcelClone() {
Parcel thisParcel = Parcel.obtain();
Parcel thatParcel = Parcel.obtain();
byte[] bytes = null;
thisParcel.writeValue(this);
bytes = thisParcel.marshall();
thatParcel.unmarshall(bytes, 0, bytes.length);
thatParcel.setDataPosition(0);
MasterSecret that = (MasterSecret)thatParcel.readValue(MasterSecret.class.getClassLoader());
thisParcel.recycle();
thatParcel.recycle();
return that;
}
}