conversations-classic/src/main/java/eu/siacs/conversations/crypto/axolotl/AxolotlService.java

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package eu.siacs.conversations.crypto.axolotl;
import android.util.Base64;
import android.util.Log;
import org.whispersystems.libaxolotl.AxolotlAddress;
import org.whispersystems.libaxolotl.DuplicateMessageException;
import org.whispersystems.libaxolotl.IdentityKey;
import org.whispersystems.libaxolotl.IdentityKeyPair;
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.SessionBuilder;
import org.whispersystems.libaxolotl.SessionCipher;
import org.whispersystems.libaxolotl.UntrustedIdentityException;
import org.whispersystems.libaxolotl.ecc.Curve;
import org.whispersystems.libaxolotl.ecc.ECKeyPair;
import org.whispersystems.libaxolotl.ecc.ECPublicKey;
import org.whispersystems.libaxolotl.protocol.CiphertextMessage;
import org.whispersystems.libaxolotl.protocol.PreKeyWhisperMessage;
import org.whispersystems.libaxolotl.protocol.WhisperMessage;
import org.whispersystems.libaxolotl.state.AxolotlStore;
import org.whispersystems.libaxolotl.state.PreKeyBundle;
import org.whispersystems.libaxolotl.state.PreKeyRecord;
import org.whispersystems.libaxolotl.state.SessionRecord;
import org.whispersystems.libaxolotl.state.SignedPreKeyRecord;
import org.whispersystems.libaxolotl.util.KeyHelper;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.HashSet;
import java.util.List;
import java.util.Map;
import java.util.Random;
import java.util.Set;
import eu.siacs.conversations.Config;
import eu.siacs.conversations.entities.Account;
import eu.siacs.conversations.entities.Contact;
import eu.siacs.conversations.entities.Conversation;
import eu.siacs.conversations.services.XmppConnectionService;
import eu.siacs.conversations.xmpp.jid.InvalidJidException;
import eu.siacs.conversations.xmpp.jid.Jid;
public class AxolotlService {
private final Account account;
private final XmppConnectionService mXmppConnectionService;
private final SQLiteAxolotlStore axolotlStore;
private final SessionMap sessions;
private int ownDeviceId;
public static class SQLiteAxolotlStore implements AxolotlStore {
public static final String PREKEY_TABLENAME = "prekeys";
public static final String SIGNED_PREKEY_TABLENAME = "signed_prekeys";
public static final String SESSION_TABLENAME = "sessions";
public static final String ACCOUNT = "account";
public static final String DEVICE_ID = "device_id";
public static final String ID = "id";
public static final String KEY = "key";
public static final String NAME = "name";
public static final String TRUSTED = "trusted";
public static final String JSONKEY_IDENTITY_KEY_PAIR = "axolotl_key";
public static final String JSONKEY_REGISTRATION_ID = "axolotl_reg_id";
public static final String JSONKEY_CURRENT_PREKEY_ID = "axolotl_cur_prekey_id";
private final Account account;
private final XmppConnectionService mXmppConnectionService;
private final IdentityKeyPair identityKeyPair;
private final int localRegistrationId;
private int currentPreKeyId = 0;
private static IdentityKeyPair generateIdentityKeyPair() {
Log.d(Config.LOGTAG, "Generating axolotl IdentityKeyPair...");
ECKeyPair identityKeyPairKeys = Curve.generateKeyPair();
IdentityKeyPair ownKey = new IdentityKeyPair(new IdentityKey(identityKeyPairKeys.getPublicKey()),
identityKeyPairKeys.getPrivateKey());
return ownKey;
}
private static int generateRegistrationId() {
Log.d(Config.LOGTAG, "Generating axolotl registration ID...");
int reg_id = KeyHelper.generateRegistrationId(false);
return reg_id;
}
public SQLiteAxolotlStore(Account account, XmppConnectionService service) {
this.account = account;
this.mXmppConnectionService = service;
this.identityKeyPair = loadIdentityKeyPair();
this.localRegistrationId = loadRegistrationId();
this.currentPreKeyId = loadCurrentPreKeyId();
for( SignedPreKeyRecord record:loadSignedPreKeys()) {
Log.d(Config.LOGTAG, "Got Axolotl signed prekey record:" + record.getId());
}
}
public int getCurrentPreKeyId() {
return currentPreKeyId;
}
// --------------------------------------
// IdentityKeyStore
// --------------------------------------
private IdentityKeyPair loadIdentityKeyPair() {
String serializedKey = this.account.getKey(JSONKEY_IDENTITY_KEY_PAIR);
IdentityKeyPair ownKey;
if( serializedKey != null ) {
try {
ownKey = new IdentityKeyPair(Base64.decode(serializedKey,Base64.DEFAULT));
return ownKey;
} catch (InvalidKeyException e) {
Log.d(Config.LOGTAG, "Invalid key stored for account " + account.getJid() + ": " + e.getMessage());
// return null;
}
} //else {
Log.d(Config.LOGTAG, "Could not retrieve axolotl key for account " + account.getJid());
ownKey = generateIdentityKeyPair();
boolean success = this.account.setKey(JSONKEY_IDENTITY_KEY_PAIR, Base64.encodeToString(ownKey.serialize(), Base64.DEFAULT));
if(success) {
mXmppConnectionService.databaseBackend.updateAccount(account);
} else {
Log.e(Config.LOGTAG, "Failed to write new key to the database!");
}
//}
return ownKey;
}
private int loadRegistrationId() {
String regIdString = this.account.getKey(JSONKEY_REGISTRATION_ID);
int reg_id;
if (regIdString != null) {
reg_id = Integer.valueOf(regIdString);
} else {
Log.d(Config.LOGTAG, "Could not retrieve axolotl registration id for account " + account.getJid());
reg_id = generateRegistrationId();
boolean success = this.account.setKey(JSONKEY_REGISTRATION_ID,""+reg_id);
if(success) {
mXmppConnectionService.databaseBackend.updateAccount(account);
} else {
Log.e(Config.LOGTAG, "Failed to write new key to the database!");
}
}
return reg_id;
}
private int loadCurrentPreKeyId() {
String regIdString = this.account.getKey(JSONKEY_CURRENT_PREKEY_ID);
int reg_id;
if (regIdString != null) {
reg_id = Integer.valueOf(regIdString);
} else {
Log.d(Config.LOGTAG, "Could not retrieve current prekey id for account " + account.getJid());
reg_id = 0;
}
return reg_id;
}
/**
* Get the local client's identity key pair.
*
* @return The local client's persistent identity key pair.
*/
@Override
public IdentityKeyPair getIdentityKeyPair() {
return identityKeyPair;
}
/**
* Return the local client's registration ID.
* <p/>
* Clients should maintain a registration ID, a random number
* between 1 and 16380 that's generated once at install time.
*
* @return the local client's registration ID.
*/
@Override
public int getLocalRegistrationId() {
return localRegistrationId;
}
/**
* Save a remote client's identity key
* <p/>
* Store a remote client's identity key as trusted.
*
* @param name The name of the remote client.
* @param identityKey The remote client's identity key.
*/
@Override
public void saveIdentity(String name, IdentityKey identityKey) {
try {
Jid contactJid = Jid.fromString(name);
Conversation conversation = this.mXmppConnectionService.find(this.account, contactJid);
if (conversation != null) {
conversation.getContact().addAxolotlIdentityKey(identityKey);
mXmppConnectionService.updateConversationUi();
mXmppConnectionService.syncRosterToDisk(conversation.getAccount());
}
} catch (final InvalidJidException e) {
Log.e(Config.LOGTAG, "Failed to save identityKey for contact name " + name + ": " + e.toString());
}
}
/**
* Verify a remote client's identity key.
* <p/>
* Determine whether a remote client's identity is trusted. Convention is
* that the TextSecure protocol is 'trust on first use.' This means that
* an identity key is considered 'trusted' if there is no entry for the recipient
* in the local store, or if it matches the saved key for a recipient in the local
* store. Only if it mismatches an entry in the local store is it considered
* 'untrusted.'
*
* @param name The name of the remote client.
* @param identityKey The identity key to verify.
* @return true if trusted, false if untrusted.
*/
@Override
public boolean isTrustedIdentity(String name, IdentityKey identityKey) {
try {
Jid contactJid = Jid.fromString(name);
Conversation conversation = this.mXmppConnectionService.find(this.account, contactJid);
if (conversation != null) {
List<IdentityKey> trustedKeys = conversation.getContact().getAxolotlIdentityKeys();
return trustedKeys.isEmpty() || trustedKeys.contains(identityKey);
} else {
return false;
}
} catch (final InvalidJidException e) {
Log.e(Config.LOGTAG, "Failed to save identityKey for contact name" + name + ": " + e.toString());
return false;
}
}
// --------------------------------------
// SessionStore
// --------------------------------------
/**
* Returns a copy of the {@link SessionRecord} corresponding to the recipientId + deviceId tuple,
* or a new SessionRecord if one does not currently exist.
* <p/>
* It is important that implementations return a copy of the current durable information. The
* returned SessionRecord may be modified, but those changes should not have an effect on the
* durable session state (what is returned by subsequent calls to this method) without the
* store method being called here first.
*
* @param address The name and device ID of the remote client.
* @return a copy of the SessionRecord corresponding to the recipientId + deviceId tuple, or
* a new SessionRecord if one does not currently exist.
*/
@Override
public SessionRecord loadSession(AxolotlAddress address) {
SessionRecord session = mXmppConnectionService.databaseBackend.loadSession(this.account, address);
return (session!=null)?session:new SessionRecord();
}
/**
* Returns all known devices with active sessions for a recipient
*
* @param name the name of the client.
* @return all known sub-devices with active sessions.
*/
@Override
public List<Integer> getSubDeviceSessions(String name) {
return mXmppConnectionService.databaseBackend.getSubDeviceSessions(account,
new AxolotlAddress(name,0));
}
/**
* Commit to storage the {@link SessionRecord} for a given recipientId + deviceId tuple.
*
* @param address the address of the remote client.
* @param record the current SessionRecord for the remote client.
*/
@Override
public void storeSession(AxolotlAddress address, SessionRecord record) {
mXmppConnectionService.databaseBackend.storeSession(account, address, record);
}
/**
* Determine whether there is a committed {@link SessionRecord} for a recipientId + deviceId tuple.
*
* @param address the address of the remote client.
* @return true if a {@link SessionRecord} exists, false otherwise.
*/
@Override
public boolean containsSession(AxolotlAddress address) {
return mXmppConnectionService.databaseBackend.containsSession(account, address);
}
/**
* Remove a {@link SessionRecord} for a recipientId + deviceId tuple.
*
* @param address the address of the remote client.
*/
@Override
public void deleteSession(AxolotlAddress address) {
mXmppConnectionService.databaseBackend.deleteSession(account, address);
}
/**
* Remove the {@link SessionRecord}s corresponding to all devices of a recipientId.
*
* @param name the name of the remote client.
*/
@Override
public void deleteAllSessions(String name) {
mXmppConnectionService.databaseBackend.deleteAllSessions(account,
new AxolotlAddress(name, 0));
}
public boolean isTrustedSession(AxolotlAddress address) {
return mXmppConnectionService.databaseBackend.isTrustedSession(this.account, address);
}
public void setTrustedSession(AxolotlAddress address, boolean trusted) {
mXmppConnectionService.databaseBackend.setTrustedSession(this.account, address,trusted);
}
// --------------------------------------
// PreKeyStore
// --------------------------------------
/**
* Load a local PreKeyRecord.
*
* @param preKeyId the ID of the local PreKeyRecord.
* @return the corresponding PreKeyRecord.
* @throws InvalidKeyIdException when there is no corresponding PreKeyRecord.
*/
@Override
public PreKeyRecord loadPreKey(int preKeyId) throws InvalidKeyIdException {
PreKeyRecord record = mXmppConnectionService.databaseBackend.loadPreKey(account, preKeyId);
if(record == null) {
throw new InvalidKeyIdException("No such PreKeyRecord: " + preKeyId);
}
return record;
}
/**
* Store a local PreKeyRecord.
*
* @param preKeyId the ID of the PreKeyRecord to store.
* @param record the PreKeyRecord.
*/
@Override
public void storePreKey(int preKeyId, PreKeyRecord record) {
mXmppConnectionService.databaseBackend.storePreKey(account, record);
currentPreKeyId = preKeyId;
boolean success = this.account.setKey(JSONKEY_CURRENT_PREKEY_ID,Integer.toString(preKeyId));
if(success) {
mXmppConnectionService.databaseBackend.updateAccount(account);
} else {
Log.e(Config.LOGTAG, "Failed to write new prekey id to the database!");
}
}
/**
* @param preKeyId A PreKeyRecord ID.
* @return true if the store has a record for the preKeyId, otherwise false.
*/
@Override
public boolean containsPreKey(int preKeyId) {
return mXmppConnectionService.databaseBackend.containsPreKey(account, preKeyId);
}
/**
* Delete a PreKeyRecord from local storage.
*
* @param preKeyId The ID of the PreKeyRecord to remove.
*/
@Override
public void removePreKey(int preKeyId) {
mXmppConnectionService.databaseBackend.deletePreKey(account, preKeyId);
}
// --------------------------------------
// SignedPreKeyStore
// --------------------------------------
/**
* Load a local SignedPreKeyRecord.
*
* @param signedPreKeyId the ID of the local SignedPreKeyRecord.
* @return the corresponding SignedPreKeyRecord.
* @throws InvalidKeyIdException when there is no corresponding SignedPreKeyRecord.
*/
@Override
public SignedPreKeyRecord loadSignedPreKey(int signedPreKeyId) throws InvalidKeyIdException {
SignedPreKeyRecord record = mXmppConnectionService.databaseBackend.loadSignedPreKey(account, signedPreKeyId);
if(record == null) {
throw new InvalidKeyIdException("No such SignedPreKeyRecord: " + signedPreKeyId);
}
return record;
}
/**
* Load all local SignedPreKeyRecords.
*
* @return All stored SignedPreKeyRecords.
*/
@Override
public List<SignedPreKeyRecord> loadSignedPreKeys() {
return mXmppConnectionService.databaseBackend.loadSignedPreKeys(account);
}
/**
* Store a local SignedPreKeyRecord.
*
* @param signedPreKeyId the ID of the SignedPreKeyRecord to store.
* @param record the SignedPreKeyRecord.
*/
@Override
public void storeSignedPreKey(int signedPreKeyId, SignedPreKeyRecord record) {
mXmppConnectionService.databaseBackend.storeSignedPreKey(account, record);
}
/**
* @param signedPreKeyId A SignedPreKeyRecord ID.
* @return true if the store has a record for the signedPreKeyId, otherwise false.
*/
@Override
public boolean containsSignedPreKey(int signedPreKeyId) {
return mXmppConnectionService.databaseBackend.containsSignedPreKey(account, signedPreKeyId);
}
/**
* Delete a SignedPreKeyRecord from local storage.
*
* @param signedPreKeyId The ID of the SignedPreKeyRecord to remove.
*/
@Override
public void removeSignedPreKey(int signedPreKeyId) {
mXmppConnectionService.databaseBackend.deleteSignedPreKey(account, signedPreKeyId);
}
}
public static class XmppAxolotlSession {
private SessionCipher cipher;
private boolean isTrusted = false;
private SQLiteAxolotlStore sqLiteAxolotlStore;
private AxolotlAddress remoteAddress;
public XmppAxolotlSession(SQLiteAxolotlStore store, AxolotlAddress remoteAddress) {
this.cipher = new SessionCipher(store, remoteAddress);
this.remoteAddress = remoteAddress;
this.sqLiteAxolotlStore = store;
this.isTrusted = sqLiteAxolotlStore.isTrustedSession(remoteAddress);
}
public void trust() {
sqLiteAxolotlStore.setTrustedSession(remoteAddress, true);
this.isTrusted = true;
}
public boolean isTrusted() {
return this.isTrusted;
}
public byte[] processReceiving(XmppAxolotlMessage.XmppAxolotlMessageHeader incomingHeader) {
byte[] plaintext = null;
try {
try {
PreKeyWhisperMessage message = new PreKeyWhisperMessage(incomingHeader.getContents());
Log.d(Config.LOGTAG,"PreKeyWhisperMessage ID:" + message.getSignedPreKeyId() + "/" + message.getPreKeyId());
plaintext = cipher.decrypt(message);
} catch (InvalidMessageException|InvalidVersionException e) {
WhisperMessage message = new WhisperMessage(incomingHeader.getContents());
plaintext = cipher.decrypt(message);
} catch (InvalidKeyException|InvalidKeyIdException| UntrustedIdentityException e) {
Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage());
}
} catch (LegacyMessageException|InvalidMessageException e) {
Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage());
} catch (DuplicateMessageException|NoSessionException e) {
Log.d(Config.LOGTAG, "Error decrypting axolotl header: " + e.getMessage());
}
return plaintext;
}
public XmppAxolotlMessage.XmppAxolotlMessageHeader processSending(byte[] outgoingMessage) {
CiphertextMessage ciphertextMessage = cipher.encrypt(outgoingMessage);
XmppAxolotlMessage.XmppAxolotlMessageHeader header =
new XmppAxolotlMessage.XmppAxolotlMessageHeader(remoteAddress.getDeviceId(),
ciphertextMessage.serialize());
return header;
}
}
private static class AxolotlAddressMap<T> {
protected Map<String, Map<Integer,T>> map;
protected final Object MAP_LOCK = new Object();
public AxolotlAddressMap() {
this.map = new HashMap<>();
}
public void put(AxolotlAddress address, T value) {
synchronized (MAP_LOCK) {
Map<Integer, T> devices = map.get(address.getName());
if (devices == null) {
devices = new HashMap<>();
map.put(address.getName(), devices);
}
devices.put(address.getDeviceId(), value);
}
}
public T get(AxolotlAddress address) {
synchronized (MAP_LOCK) {
Map<Integer, T> devices = map.get(address.getName());
if(devices == null) {
return null;
}
return devices.get(address.getDeviceId());
}
}
public Map<Integer, T> getAll(AxolotlAddress address) {
synchronized (MAP_LOCK) {
Map<Integer, T> devices = map.get(address.getName());
if(devices == null) {
return new HashMap<>();
}
return devices;
}
}
public boolean hasAny(AxolotlAddress address) {
synchronized (MAP_LOCK) {
Map<Integer, T> devices = map.get(address.getName());
return devices != null && !devices.isEmpty();
}
}
}
private static class SessionMap extends AxolotlAddressMap<XmppAxolotlSession> {
public SessionMap(SQLiteAxolotlStore store, Account account) {
super();
this.fillMap(store, account);
}
private void fillMap(SQLiteAxolotlStore store, Account account) {
for(Contact contact:account.getRoster().getContacts()){
Jid bareJid = contact.getJid().toBareJid();
if(bareJid == null) {
continue; // FIXME: handle this?
}
String address = bareJid.toString();
List<Integer> deviceIDs = store.getSubDeviceSessions(address);
for(Integer deviceId:deviceIDs) {
AxolotlAddress axolotlAddress = new AxolotlAddress(address, deviceId);
this.put(axolotlAddress, new XmppAxolotlSession(store, axolotlAddress));
}
}
}
}
}
public AxolotlService(Account account, XmppConnectionService connectionService) {
this.mXmppConnectionService = connectionService;
this.account = account;
this.axolotlStore = new SQLiteAxolotlStore(this.account, this.mXmppConnectionService);
this.sessions = new SessionMap(axolotlStore, account);
this.ownDeviceId = axolotlStore.getLocalRegistrationId();
}
public void trustSession(AxolotlAddress counterpart) {
XmppAxolotlSession session = sessions.get(counterpart);
if(session != null) {
session.trust();
}
}
public boolean isTrustedSession(AxolotlAddress counterpart) {
XmppAxolotlSession session = sessions.get(counterpart);
return session != null && session.isTrusted();
}
private AxolotlAddress getAddressForJid(Jid jid) {
return new AxolotlAddress(jid.toString(), 0);
}
private Set<XmppAxolotlSession> findOwnSessions() {
AxolotlAddress ownAddress = getAddressForJid(account.getJid());
Set<XmppAxolotlSession> ownDeviceSessions = new HashSet<>(this.sessions.getAll(ownAddress).values());
return ownDeviceSessions;
}
private Set<XmppAxolotlSession> findSessionsforContact(Contact contact) {
AxolotlAddress contactAddress = getAddressForJid(contact.getJid());
Set<XmppAxolotlSession> sessions = new HashSet<>(this.sessions.getAll(contactAddress).values());
return sessions;
}
private boolean hasAny(Contact contact) {
AxolotlAddress contactAddress = getAddressForJid(contact.getJid());
return sessions.hasAny(contactAddress);
}
public int getOwnDeviceId() {
return ownDeviceId;
}
private void createSessionsIfNeeded(Contact contact) throws NoSessionsCreatedException {
}
public XmppAxolotlMessage processSending(Contact contact, String outgoingMessage) throws NoSessionsCreatedException {
XmppAxolotlMessage message = new XmppAxolotlMessage(contact, ownDeviceId, outgoingMessage);
createSessionsIfNeeded(contact);
Log.d(Config.LOGTAG, "Building axolotl foreign headers...");
for(XmppAxolotlSession session : findSessionsforContact(contact)) {
// if(!session.isTrusted()) {
// TODO: handle this properly
// continue;
// }
message.addHeader(session.processSending(message.getInnerKey()));
}
Log.d(Config.LOGTAG, "Building axolotl own headers...");
for(XmppAxolotlSession session : findOwnSessions()) {
// if(!session.isTrusted()) {
// TODO: handle this properly
// continue;
// }
message.addHeader(session.processSending(message.getInnerKey()));
}
return message;
}
public XmppAxolotlMessage.XmppAxolotlPlaintextMessage processReceiving(XmppAxolotlMessage message) {
XmppAxolotlMessage.XmppAxolotlPlaintextMessage plaintextMessage = null;
AxolotlAddress senderAddress = new AxolotlAddress(message.getContact().getJid().toBareJid().toString(),
message.getSenderDeviceId());
XmppAxolotlSession session = sessions.get(senderAddress);
if (session == null) {
Log.d(Config.LOGTAG, "No axolotl session found while parsing received message " + message);
// TODO: handle this properly
session = new XmppAxolotlSession(axolotlStore, senderAddress);
}
for(XmppAxolotlMessage.XmppAxolotlMessageHeader header : message.getHeaders()) {
if (header.getRecipientDeviceId() == ownDeviceId) {
Log.d(Config.LOGTAG, "Found axolotl header matching own device ID, processing...");
byte[] payloadKey = session.processReceiving(header);
if (payloadKey != null) {
Log.d(Config.LOGTAG, "Got payload key from axolotl header. Decrypting message...");
plaintextMessage = message.decrypt(session, payloadKey);
}
}
}
return plaintextMessage;
}
}