Smack/smack-openpgp/src/main/java/org/jivesoftware/smackx/ox/OpenPgpManager.java

245 lines
10 KiB
Java

/**
*
* Copyright 2017 Florian Schmaus, 2018 Paul Schaub.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jivesoftware.smackx.ox;
import static org.jivesoftware.smackx.ox.PubSubDelegate.PEP_NODE_PUBLIC_KEYS;
import static org.jivesoftware.smackx.ox.PubSubDelegate.PEP_NODE_PUBLIC_KEYS_NOTIFY;
import java.security.SecureRandom;
import java.util.Map;
import java.util.WeakHashMap;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jivesoftware.smack.Manager;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.XMPPConnection;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.util.Async;
import org.jivesoftware.smackx.disco.ServiceDiscoveryManager;
import org.jivesoftware.smackx.ox.callback.AskForBackupCodeCallback;
import org.jivesoftware.smackx.ox.callback.DisplayBackupCodeCallback;
import org.jivesoftware.smackx.ox.callback.SecretKeyRestoreSelectionCallback;
import org.jivesoftware.smackx.ox.element.PublicKeysListElement;
import org.jivesoftware.smackx.ox.element.SecretkeyElement;
import org.jivesoftware.smackx.ox.exception.CorruptedOpenPgpKeyException;
import org.jivesoftware.smackx.ox.exception.InvalidBackupCodeException;
import org.jivesoftware.smackx.ox.exception.MissingOpenPgpKeyPairException;
import org.jivesoftware.smackx.pep.PEPListener;
import org.jivesoftware.smackx.pep.PEPManager;
import org.jivesoftware.smackx.pubsub.EventElement;
import org.jivesoftware.smackx.pubsub.ItemsExtension;
import org.jivesoftware.smackx.pubsub.PayloadItem;
import org.jivesoftware.smackx.pubsub.PubSubException;
import org.jivesoftware.smackx.pubsub.PubSubManager;
import org.jxmpp.jid.EntityBareJid;
public final class OpenPgpManager extends Manager {
private static final Logger LOGGER = Logger.getLogger(OpenPgpManager.class.getName());
/**
* Map of instances.
*/
private static final Map<XMPPConnection, OpenPgpManager> INSTANCES = new WeakHashMap<>();
/**
* {@link OpenPgpProvider} responsible for processing keys, encrypting and decrypting messages and so on.
*/
private OpenPgpProvider provider;
/**
* Private constructor to avoid instantiation without putting the object into {@code INSTANCES}.
*
* @param connection xmpp connection.
*/
private OpenPgpManager(XMPPConnection connection) {
super(connection);
// Subscribe to public key changes
PEPManager.getInstanceFor(connection()).addPEPListener(metadataListener);
ServiceDiscoveryManager.getInstanceFor(connection())
.addFeature(PEP_NODE_PUBLIC_KEYS_NOTIFY);
}
/**
* Get the instance of the {@link OpenPgpManager} which belongs to the {@code connection}.
*
* @param connection xmpp connection.
* @return instance of the manager.
*/
public static OpenPgpManager getInstanceFor(XMPPConnection connection) {
OpenPgpManager manager = INSTANCES.get(connection);
if (manager == null) {
manager = new OpenPgpManager(connection);
INSTANCES.put(connection, manager);
}
return manager;
}
/**
* Set the {@link OpenPgpProvider} which will be used to process incoming OpenPGP elements,
* as well as to execute cryptographic operations.
*
* @param provider OpenPgpProvider.
*/
public void setOpenPgpProvider(OpenPgpProvider provider) {
this.provider = provider;
}
/**
* Return the upper-case hex encoded OpenPGP v4 fingerprint of our key pair.
*
* @return fingerprint.
* @throws CorruptedOpenPgpKeyException if for some reason we cannot determine our fingerprint.
*/
public OpenPgpV4Fingerprint getOurFingerprint() throws CorruptedOpenPgpKeyException {
throwIfNoProviderSet();
return provider.primaryOpenPgpKeyPairFingerprint();
}
/**
* Determine, if we can sync secret keys using private PEP nodes as described in the XEP.
* Requirements on the server side are support for PEP and support for the whitelist access model of PubSub.
*
* @see <a href="https://xmpp.org/extensions/xep-0373.html#synchro-pep">XEP-0373 §5</a>
*
* @return true, if the server supports secret key backups, otherwise false.
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws InterruptedException
* @throws SmackException.NoResponseException
*/
public boolean serverSupportsSecretKeyBackups()
throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
SmackException.NoResponseException {
boolean pep = PEPManager.getInstanceFor(connection()).isSupported();
boolean whitelist = PubSubManager.getInstance(connection(), connection().getUser().asBareJid())
.getSupportedFeatures().containsFeature("http://jabber.org/protocol/pubsub#access-whitelist");
return pep && whitelist;
}
/**
* Upload the encrypted secret key to a private PEP node.
*
* @see <a href="https://xmpp.org/extensions/xep-0373.html#synchro-pep">XEP-0373 §5</a>
*
* @param callback callback, which will receive the backup password used to encrypt the secret key.
* @throws CorruptedOpenPgpKeyException if the secret key is corrupted or can for some reason not be serialized.
* @throws InterruptedException
* @throws PubSubException.NotALeafNodeException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
*/
public void backupSecretKeyToServer(DisplayBackupCodeCallback callback)
throws CorruptedOpenPgpKeyException, InterruptedException, PubSubException.NotALeafNodeException,
XMPPException.XMPPErrorException, SmackException.NotConnectedException, SmackException.NoResponseException,
MissingOpenPgpKeyPairException {
throwIfNoProviderSet();
String backupCode = generateBackupPassword();
SecretkeyElement secretKey = provider.createSecretkeyElement(null, backupCode); // TODO
PubSubDelegate.depositSecretKey(connection(), secretKey);
callback.displayBackupCode(backupCode);
}
public void deleteSecretKeyServerBackup()
throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
SmackException.NoResponseException {
PubSubDelegate.deleteSecretKeyNode(connection());
}
public void restoreSecretKeyServerBackup(AskForBackupCodeCallback codeCallback,
SecretKeyRestoreSelectionCallback selectionCallback)
throws InterruptedException, PubSubException.NotALeafNodeException, XMPPException.XMPPErrorException,
SmackException.NotConnectedException, SmackException.NoResponseException, CorruptedOpenPgpKeyException,
InvalidBackupCodeException {
throwIfNoProviderSet();
SecretkeyElement backup = PubSubDelegate.fetchSecretKey(connection());
provider.restoreSecretKeyBackup(backup, codeCallback.askForBackupCode(), selectionCallback);
// TODO: catch InvalidBackupCodeException in order to prevent re-fetching the backup on next try.
}
/**
* {@link PEPListener} that listens for changes to the OX public keys metadata node.
*
* @see <a href="https://xmpp.org/extensions/xep-0373.html#pubsub-notifications">XEP-0373 §4.4</a>
*/
private final PEPListener metadataListener = new PEPListener() {
@Override
public void eventReceived(final EntityBareJid from, final EventElement event, Message message) {
if (PEP_NODE_PUBLIC_KEYS.equals(event.getEvent().getNode())) {
LOGGER.log(Level.INFO, "Received OpenPGP metadata update from " + from);
Async.go(new Runnable() {
@Override
public void run() {
ItemsExtension items = (ItemsExtension) event.getExtensions().get(0);
PayloadItem<?> payload = (PayloadItem) items.getItems().get(0);
PublicKeysListElement listElement = (PublicKeysListElement) payload.getPayload();
try {
provider.storePublicKeysList(connection(), listElement, from.asBareJid());
} catch (Exception e) {
LOGGER.log(Level.WARNING, "Error processing OpenPGP metadata update from " + from + ".", e);
}
}
}, "ProcessOXMetadata");
}
}
};
/**
* Generate a secure backup code.
*
* @see <a href="https://xmpp.org/extensions/xep-0373.html#sect-idm140425111347232">XEP-0373 §5.3</a>
* @return backup code
*/
private static String generateBackupPassword() {
final String alphabet = "123456789ABCDEFGHIJKLMNPQRSTUVWXYZ";
SecureRandom random = new SecureRandom();
StringBuilder code = new StringBuilder();
// 6 blocks
for (int i = 0; i < 6; i++) {
// of 4 chars
for (int j = 0; j < 4; j++) {
char c = alphabet.charAt(random.nextInt(alphabet.length()));
code.append(c);
}
// dash after every block except the last one
if (i != 5) {
code.append('-');
}
}
return code.toString();
}
/**
* Throw an {@link IllegalStateException} if no {@link OpenPgpProvider} is set.
* The OpenPgpProvider is used to process information related to RFC-4880.
*/
private void throwIfNoProviderSet() {
if (provider == null) {
throw new IllegalStateException("No OpenPgpProvider set!");
}
}
}