package de.pixart.messenger.crypto.axolotl; import android.support.annotation.NonNull; import android.support.annotation.Nullable; import org.whispersystems.libaxolotl.AxolotlAddress; import org.whispersystems.libaxolotl.DuplicateMessageException; import org.whispersystems.libaxolotl.IdentityKey; import org.whispersystems.libaxolotl.InvalidKeyException; import org.whispersystems.libaxolotl.InvalidKeyIdException; import org.whispersystems.libaxolotl.InvalidMessageException; import org.whispersystems.libaxolotl.InvalidVersionException; import org.whispersystems.libaxolotl.LegacyMessageException; import org.whispersystems.libaxolotl.NoSessionException; import org.whispersystems.libaxolotl.SessionCipher; import org.whispersystems.libaxolotl.UntrustedIdentityException; import org.whispersystems.libaxolotl.protocol.CiphertextMessage; import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage; import org.whispersystems.libaxolotl.protocol.WhisperMessage; import org.whispersystems.libaxolotl.util.guava.Optional; import de.pixart.messenger.entities.Account; public class XmppAxolotlSession implements Comparable { private final SessionCipher cipher; private final SQLiteAxolotlStore sqLiteAxolotlStore; private final AxolotlAddress remoteAddress; private final Account account; private IdentityKey identityKey; private Integer preKeyId = null; private boolean fresh = true; public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress, IdentityKey identityKey) { this(account, store, remoteAddress); this.identityKey = identityKey; } public XmppAxolotlSession(Account account, SQLiteAxolotlStore store, AxolotlAddress remoteAddress) { this.cipher = new SessionCipher(store, remoteAddress); this.remoteAddress = remoteAddress; this.sqLiteAxolotlStore = store; this.account = account; } public Integer getPreKeyId() { return preKeyId; } public void resetPreKeyId() { preKeyId = null; } public String getFingerprint() { return identityKey == null ? null : identityKey.getFingerprint().replaceAll("\\s", ""); } public IdentityKey getIdentityKey() { return identityKey; } public AxolotlAddress getRemoteAddress() { return remoteAddress; } public boolean isFresh() { return fresh; } public void setNotFresh() { this.fresh = false; } protected void setTrust(FingerprintStatus status) { sqLiteAxolotlStore.setFingerprintStatus(getFingerprint(), status); } public FingerprintStatus getTrust() { FingerprintStatus status = sqLiteAxolotlStore.getFingerprintStatus(getFingerprint()); return (status == null) ? FingerprintStatus.createActiveUndecided() : status; } @Nullable public byte[] processReceiving(AxolotlKey encryptedKey) throws CryptoFailedException { byte[] plaintext; FingerprintStatus status = getTrust(); if (!status.isCompromised()) { try { CiphertextMessage ciphertextMessage; try { ciphertextMessage = new PreKeyWhisperMessage(encryptedKey.key); Optional optionalPreKeyId = ((PreKeyWhisperMessage) ciphertextMessage).getPreKeyId(); IdentityKey identityKey = ((PreKeyWhisperMessage) ciphertextMessage).getIdentityKey(); if (!optionalPreKeyId.isPresent()) { throw new CryptoFailedException("PreKeyWhisperMessage did not contain a PreKeyId"); } preKeyId = optionalPreKeyId.get(); if (this.identityKey != null && !this.identityKey.equals(identityKey)) { throw new CryptoFailedException("Received PreKeyWhisperMessage but preexisting identity key changed."); } this.identityKey = identityKey; } catch (InvalidVersionException | InvalidMessageException e) { ciphertextMessage = new WhisperMessage(encryptedKey.key); } if (ciphertextMessage instanceof PreKeyWhisperMessage) { plaintext = cipher.decrypt((PreKeyWhisperMessage) ciphertextMessage); } else { plaintext = cipher.decrypt((WhisperMessage) ciphertextMessage); } } catch (InvalidKeyException | LegacyMessageException | InvalidMessageException | DuplicateMessageException | NoSessionException | InvalidKeyIdException | UntrustedIdentityException e) { if (!(e instanceof DuplicateMessageException)) { e.printStackTrace(); } throw new CryptoFailedException("Error decrypting WhisperMessage " + e.getClass().getSimpleName() + ": " + e.getMessage()); } if (!status.isActive()) { setTrust(status.toActive()); } } else { throw new CryptoFailedException("not encrypting omemo message from fingerprint "+getFingerprint()+" because it was marked as compromised"); } return plaintext; } @Nullable public AxolotlKey processSending(@NonNull byte[] outgoingMessage) { FingerprintStatus status = getTrust(); if (status.isTrustedAndActive()) { CiphertextMessage ciphertextMessage = cipher.encrypt(outgoingMessage); return new AxolotlKey(ciphertextMessage.serialize(),ciphertextMessage.getType() == CiphertextMessage.PREKEY_TYPE); } else { return null; } } public Account getAccount() { return account; } @Override public int compareTo(XmppAxolotlSession o) { return getTrust().compareTo(o.getTrust()); } public static class AxolotlKey { public final byte[] key; public final boolean prekey; public AxolotlKey(byte[] key, boolean prekey) { this.key = key; this.prekey = prekey; } } }