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

610 lines
28 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.util.PubSubDelegate.PEP_NODE_PUBLIC_KEYS;
import static org.jivesoftware.smackx.ox.util.PubSubDelegate.PEP_NODE_PUBLIC_KEYS_NOTIFY;
import static org.jivesoftware.smackx.ox.util.PubSubDelegate.fetchPubkey;
import static org.jivesoftware.smackx.ox.util.PubSubDelegate.publishPublicKey;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.security.InvalidAlgorithmParameterException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.SecureRandom;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Map;
import java.util.Set;
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.chat2.Chat;
import org.jivesoftware.smack.chat2.ChatManager;
import org.jivesoftware.smack.chat2.IncomingChatMessageListener;
import org.jivesoftware.smack.packet.Message;
import org.jivesoftware.smack.util.Async;
import org.jivesoftware.smack.util.stringencoder.Base64;
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.SecretKeyBackupSelectionCallback;
import org.jivesoftware.smackx.ox.callback.SecretKeyRestoreSelectionCallback;
import org.jivesoftware.smackx.ox.chat.OpenPgpContact;
import org.jivesoftware.smackx.ox.chat.OpenPgpFingerprints;
import org.jivesoftware.smackx.ox.element.CryptElement;
import org.jivesoftware.smackx.ox.element.OpenPgpContentElement;
import org.jivesoftware.smackx.ox.element.OpenPgpElement;
import org.jivesoftware.smackx.ox.element.PubkeyElement;
import org.jivesoftware.smackx.ox.element.PublicKeysListElement;
import org.jivesoftware.smackx.ox.element.SecretkeyElement;
import org.jivesoftware.smackx.ox.element.SignElement;
import org.jivesoftware.smackx.ox.element.SigncryptElement;
import org.jivesoftware.smackx.ox.exception.InvalidBackupCodeException;
import org.jivesoftware.smackx.ox.exception.MissingOpenPgpKeyPairException;
import org.jivesoftware.smackx.ox.exception.MissingOpenPgpPublicKeyException;
import org.jivesoftware.smackx.ox.exception.MissingUserIdOnKeyException;
import org.jivesoftware.smackx.ox.exception.SmackOpenPgpException;
import org.jivesoftware.smackx.ox.listener.internal.CryptElementReceivedListener;
import org.jivesoftware.smackx.ox.listener.internal.SignElementReceivedListener;
import org.jivesoftware.smackx.ox.listener.internal.SigncryptElementReceivedListener;
import org.jivesoftware.smackx.ox.util.KeyBytesAndFingerprint;
import org.jivesoftware.smackx.ox.util.PubSubDelegate;
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.LeafNode;
import org.jivesoftware.smackx.pubsub.PayloadItem;
import org.jivesoftware.smackx.pubsub.PubSubException;
import org.jivesoftware.smackx.pubsub.PubSubManager;
import org.jxmpp.jid.BareJid;
import org.jxmpp.jid.EntityBareJid;
import org.xmlpull.v1.XmlPullParserException;
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 final Map<BareJid, OpenPgpContact> openPgpCapableContacts = new HashMap<>();
private final Set<SigncryptElementReceivedListener> signcryptElementReceivedListeners = new HashSet<>();
private final Set<SignElementReceivedListener> signElementReceivedListeners = new HashSet<>();
private final Set<CryptElementReceivedListener> cryptElementReceivedListeners = new HashSet<>();
/**
* Private constructor to avoid instantiation without putting the object into {@code INSTANCES}.
*
* @param connection xmpp connection.
*/
private OpenPgpManager(XMPPConnection connection) {
super(connection);
ChatManager.getInstanceFor(connection).addIncomingListener(incomingOpenPgpMessageListener);
}
/**
* 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 registered {@link OpenPgpProvider}.
*
* @return provider.
*/
OpenPgpProvider getOpenPgpProvider() {
return provider;
}
/**
* Generate a fresh OpenPGP key pair, given we don't have one already.
* Publish the public key to the Public Key Node and update the Public Key Metadata Node with our keys fingerprint.
* Lastly register a {@link PEPListener} which listens for updates to Public Key Metadata Nodes.
*
* @throws NoSuchAlgorithmException if we are missing an algorithm to generate a fresh key pair.
* @throws NoSuchProviderException if we are missing a suitable {@link java.security.Provider}.
* @throws SmackOpenPgpException if something bad happens during key generation/loading.
* @throws InterruptedException
* @throws PubSubException.NotALeafNodeException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
*/
public void announceSupportAndPublish()
throws NoSuchAlgorithmException, NoSuchProviderException, SmackOpenPgpException,
InterruptedException, PubSubException.NotALeafNodeException, XMPPException.XMPPErrorException,
SmackException.NotConnectedException, SmackException.NoResponseException, IOException,
InvalidAlgorithmParameterException, SmackException.NotLoggedInException {
throwIfNoProviderSet();
throwIfNotAuthenticated();
BareJid ourJid = connection().getUser().asBareJid();
OpenPgpV4Fingerprint primaryFingerprint = getOurFingerprint();
if (primaryFingerprint == null) {
primaryFingerprint = generateAndImportKeyPair(ourJid);
}
// Create <pubkey/> element
PubkeyElement pubkeyElement;
try {
pubkeyElement = createPubkeyElement(ourJid, primaryFingerprint, new Date());
} catch (MissingOpenPgpPublicKeyException e) {
throw new AssertionError("Cannot publish our public key, since it is missing (MUST NOT happen!)");
}
// publish it
publishPublicKey(connection(), pubkeyElement, primaryFingerprint);
// Subscribe to public key changes
PEPManager.getInstanceFor(connection()).addPEPListener(metadataListener);
ServiceDiscoveryManager.getInstanceFor(connection())
.addFeature(PEP_NODE_PUBLIC_KEYS_NOTIFY);
}
public OpenPgpV4Fingerprint generateAndImportKeyPair(BareJid ourJid)
throws NoSuchAlgorithmException, IOException, InvalidAlgorithmParameterException, NoSuchProviderException,
SmackOpenPgpException {
KeyBytesAndFingerprint bytesAndFingerprint = provider.generateOpenPgpKeyPair(ourJid);
OpenPgpV4Fingerprint fingerprint = bytesAndFingerprint.getFingerprint();
// This should never throw, since we set our jid literally one line above this comment.
try {
provider.importSecretKey(ourJid, bytesAndFingerprint.getBytes());
} catch (MissingUserIdOnKeyException e) {
throw new AssertionError(e);
}
return fingerprint;
}
/**
* Return the upper-case hex encoded OpenPGP v4 fingerprint of our key pair.
*
* @return fingerprint.
*/
public OpenPgpV4Fingerprint getOurFingerprint() {
throwIfNoProviderSet();
return provider.getStore().getPrimaryOpenPgpKeyPairFingerprint();
}
/**
* Return an OpenPGP capable contact.
* This object can be used as an entry point to OpenPGP related API.
*
* @param jid {@link BareJid} of the contact.
* @return {@link OpenPgpContact}.
* @throws SmackOpenPgpException if something happens while gathering fingerprints.
* @throws InterruptedException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
*/
public OpenPgpContact getOpenPgpContact(EntityBareJid jid)
throws SmackOpenPgpException, InterruptedException, XMPPException.XMPPErrorException,
SmackException.NotConnectedException, SmackException.NoResponseException,
SmackException.NotLoggedInException {
throwIfNotAuthenticated();
OpenPgpContact openPgpContact = openPgpCapableContacts.get(jid);
if (openPgpContact == null) {
OpenPgpFingerprints theirKeys = determineContactsKeys(jid);
OpenPgpFingerprints ourKeys = determineContactsKeys(connection().getUser().asBareJid());
Chat chat = ChatManager.getInstanceFor(connection()).chatWith(jid);
openPgpContact = new OpenPgpContact(getOpenPgpProvider(), chat, ourKeys, theirKeys);
openPgpCapableContacts.put(jid, openPgpContact);
}
return openPgpContact;
}
/**
* 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, SmackException.NotLoggedInException {
throwIfNotAuthenticated();
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 displayCodeCallback callback, which will receive the backup password used to encrypt the secret key.
* @param selectKeyCallback callback, which will receive the users choice of which keys will be backed up.
* @throws InterruptedException
* @throws PubSubException.NotALeafNodeException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
*/
public void backupSecretKeyToServer(DisplayBackupCodeCallback displayCodeCallback,
SecretKeyBackupSelectionCallback selectKeyCallback)
throws InterruptedException, PubSubException.NotALeafNodeException,
XMPPException.XMPPErrorException, SmackException.NotConnectedException, SmackException.NoResponseException,
SmackException.NotLoggedInException, SmackOpenPgpException, IOException {
throwIfNoProviderSet();
throwIfNotAuthenticated();
BareJid ownJid = connection().getUser().asBareJid();
String backupCode = generateBackupPassword();
Set<OpenPgpV4Fingerprint> availableKeyPairs = provider.getStore().getAvailableKeyPairFingerprints(ownJid);
Set<OpenPgpV4Fingerprint> selectedKeyPairs = selectKeyCallback.selectKeysToBackup(availableKeyPairs);
SecretkeyElement secretKey = createSecretkeyElement(ownJid, selectedKeyPairs, backupCode);
PubSubDelegate.depositSecretKey(connection(), secretKey);
displayCodeCallback.displayBackupCode(backupCode);
}
/**
* Delete the private {@link LeafNode} containing our secret key backup.
*
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws InterruptedException
* @throws SmackException.NoResponseException
*/
public void deleteSecretKeyServerBackup()
throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException,
SmackException.NoResponseException, SmackException.NotLoggedInException {
throwIfNotAuthenticated();
PubSubDelegate.deleteSecretKeyNode(connection());
}
/**
* Fetch a secret key backup from the server and try to restore a selected secret key from it.
*
* @param codeCallback callback for prompting the user to provide the secret backup code.
* @param selectionCallback callback allowing the user to select a secret key which will be restored.
* @throws InterruptedException
* @throws PubSubException.NotALeafNodeException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
* @throws SmackOpenPgpException if something goes wrong while restoring the secret key.
* @throws InvalidBackupCodeException if the user-provided backup code is invalid.
*/
public void restoreSecretKeyServerBackup(AskForBackupCodeCallback codeCallback,
SecretKeyRestoreSelectionCallback selectionCallback)
throws InterruptedException, PubSubException.NotALeafNodeException, XMPPException.XMPPErrorException,
SmackException.NotConnectedException, SmackException.NoResponseException, SmackOpenPgpException,
InvalidBackupCodeException, SmackException.NotLoggedInException {
throwIfNoProviderSet();
throwIfNotAuthenticated();
SecretkeyElement backup = PubSubDelegate.fetchSecretKey(connection());
if (backup == null) {
// TODO
return;
}
byte[] encrypted = Base64.decode(backup.getB64Data());
// provider.restoreSecretKeyBackup(backup, codeCallback.askForBackupCode(), selectionCallback);
// TODO: catch InvalidBackupCodeException in order to prevent re-fetching the backup on next try.
}
/**
* Determine which keys belong to a user and fetch any missing keys.
*
* @param jid {@link BareJid} of the user in question.
* @return {@link OpenPgpFingerprints} object containing the announced, available and unfetchable keys of the user.
* @throws SmackOpenPgpException
* @throws InterruptedException
* @throws XMPPException.XMPPErrorException
* @throws SmackException.NotConnectedException
* @throws SmackException.NoResponseException
*/
private OpenPgpFingerprints determineContactsKeys(BareJid jid)
throws SmackOpenPgpException, InterruptedException, XMPPException.XMPPErrorException,
SmackException.NotConnectedException, SmackException.NoResponseException {
Set<OpenPgpV4Fingerprint> announced = provider.getStore().getAnnouncedKeysFingerprints(jid).keySet();
Set<OpenPgpV4Fingerprint> available = provider.getStore().getAvailableKeysFingerprints(jid).keySet();
Map<OpenPgpV4Fingerprint, Throwable> unfetched = new HashMap<>();
for (OpenPgpV4Fingerprint f : announced) {
if (!available.contains(f)) {
try {
PubkeyElement pubkeyElement = PubSubDelegate.fetchPubkey(connection(), jid, f);
if (pubkeyElement == null) {
continue;
}
processPublicKey(pubkeyElement, jid);
available.add(f);
} catch (PubSubException.NotAPubSubNodeException | PubSubException.NotALeafNodeException e) {
LOGGER.log(Level.WARNING, "Could not fetch public key " + f.toString() + " of user " + jid.toString(), e);
unfetched.put(f, e);
} catch (MissingUserIdOnKeyException e) {
LOGGER.log(Level.WARNING, "Key does not contain user-id of " + jid + ". Ignoring the key.", e);
unfetched.put(f, e);
} catch (IOException e) {
LOGGER.log(Level.WARNING, "Could not import key " + f.toString() + " of user " + jid.toString(), e);
}
}
}
return new OpenPgpFingerprints(jid, announced, available, unfetched);
}
/**
* {@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, final Message message) {
if (PEP_NODE_PUBLIC_KEYS.equals(event.getEvent().getNode())) {
final BareJid contact = from.asBareJid();
LOGGER.log(Level.INFO, "Received OpenPGP metadata update from " + contact);
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();
Map<OpenPgpV4Fingerprint, Date> announcedKeys = new HashMap<>();
for (OpenPgpV4Fingerprint f : listElement.getMetadata().keySet()) {
PublicKeysListElement.PubkeyMetadataElement meta = listElement.getMetadata().get(f);
announcedKeys.put(meta.getV4Fingerprint(), meta.getDate());
}
provider.getStore().setAnnouncedKeysFingerprints(contact, announcedKeys);
Set<OpenPgpV4Fingerprint> missingKeys = listElement.getMetadata().keySet();
try {
missingKeys.removeAll(provider.getStore().getAvailableKeysFingerprints(contact).keySet());
for (OpenPgpV4Fingerprint missing : missingKeys) {
try {
PubkeyElement pubkeyElement = fetchPubkey(connection(), contact, missing);
processPublicKey(pubkeyElement, contact);
} catch (Exception e) {
LOGGER.log(Level.WARNING, "Error fetching missing OpenPGP key " + missing.toString(), e);
}
}
} catch (Exception e) {
LOGGER.log(Level.WARNING, "Error processing OpenPGP metadata update from " + contact + ".", e);
}
}
}, "ProcessOXMetadata");
}
}
};
private final IncomingChatMessageListener incomingOpenPgpMessageListener =
new IncomingChatMessageListener() {
@Override
public void newIncomingMessage(EntityBareJid from, Message message, Chat chat) {
OpenPgpElement element = message.getExtension(OpenPgpElement.ELEMENT, OpenPgpElement.NAMESPACE);
if (element == null) {
// Message does not contain an OpenPgpElement -> discard
return;
}
OpenPgpContact contact;
try {
contact = getOpenPgpContact(from);
} catch (SmackOpenPgpException | InterruptedException | XMPPException.XMPPErrorException |
SmackException.NotLoggedInException | SmackException.NotConnectedException |
SmackException.NoResponseException e) {
LOGGER.log(Level.WARNING, "Could not begin encrypted chat with " + from, e);
return;
}
OpenPgpContentElement contentElement = null;
try {
contentElement = contact.receive(element);
} catch (SmackOpenPgpException e) {
LOGGER.log(Level.WARNING, "Could not decrypt incoming OpenPGP encrypted message", e);
} catch (XmlPullParserException | IOException e) {
LOGGER.log(Level.WARNING, "Invalid XML content of incoming OpenPGP encrypted message", e);
} catch (MissingOpenPgpKeyPairException e) {
LOGGER.log(Level.WARNING, "Could not decrypt incoming OpenPGP encrypted message due to missing secret key", e);
}
if (contentElement instanceof SigncryptElement) {
for (SigncryptElementReceivedListener l : signcryptElementReceivedListeners) {
l.signcryptElementReceived(contact, message, (SigncryptElement) contentElement);
}
return;
}
if (contentElement instanceof SignElement) {
for (SignElementReceivedListener l : signElementReceivedListeners) {
l.signElementReceived(contact, message, (SignElement) contentElement);
}
return;
}
if (contentElement instanceof CryptElement) {
for (CryptElementReceivedListener l : cryptElementReceivedListeners) {
l.cryptElementReceived(contact, message, (CryptElement) contentElement);
}
return;
}
}
};
/*
Private stuff.
*/
private void processPublicKey(PubkeyElement pubkeyElement, BareJid owner)
throws MissingUserIdOnKeyException, IOException, SmackOpenPgpException {
byte[] base64 = pubkeyElement.getDataElement().getB64Data();
provider.importPublicKey(owner, Base64.decode(base64));
}
/**
* 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();
}
private PubkeyElement createPubkeyElement(BareJid owner,
OpenPgpV4Fingerprint fingerprint,
Date date)
throws MissingOpenPgpPublicKeyException {
byte[] keyBytes = provider.getStore().getPublicKeyRingBytes(owner, fingerprint);
return createPubkeyElement(keyBytes, date);
}
private static PubkeyElement createPubkeyElement(byte[] bytes, Date date) {
return new PubkeyElement(new PubkeyElement.PubkeyDataElement(Base64.encode(bytes)), date);
}
private SecretkeyElement createSecretkeyElement(BareJid owner,
Set<OpenPgpV4Fingerprint> fingerprints,
String backupCode) throws SmackOpenPgpException, IOException {
ByteArrayOutputStream buffer = new ByteArrayOutputStream();
for (OpenPgpV4Fingerprint fingerprint : fingerprints) {
try {
byte[] bytes = provider.getStore().getSecretKeyRingBytes(owner, fingerprint);
buffer.write(bytes);
} catch (MissingOpenPgpKeyPairException | IOException e) {
LOGGER.log(Level.WARNING, "Cannot backup secret key " + Long.toHexString(fingerprint.getKeyId()) + ".", e);
}
}
return createSecretkeyElement(buffer.toByteArray(), backupCode);
}
private SecretkeyElement createSecretkeyElement(byte[] keys, String backupCode)
throws SmackOpenPgpException, IOException {
byte[] encrypted = provider.symmetricallyEncryptWithPassword(keys, backupCode);
return new SecretkeyElement(Base64.encode(encrypted));
}
void addSigncryptReceivedListener(SigncryptElementReceivedListener listener) {
signcryptElementReceivedListeners.add(listener);
}
void removeSigncryptElementReceivedListener(SigncryptElementReceivedListener listener) {
signcryptElementReceivedListeners.remove(listener);
}
void addSignElementReceivedListener(SignElementReceivedListener listener) {
signElementReceivedListeners.add(listener);
}
void removeSignElementReceivedListener(SignElementReceivedListener listener) {
signElementReceivedListeners.remove(listener);
}
void addCryptElementReceivedListener(CryptElementReceivedListener listener) {
cryptElementReceivedListeners.add(listener);
}
void removeCryptElementReceivedListener(CryptElementReceivedListener listener) {
cryptElementReceivedListeners.remove(listener);
}
/**
* 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!");
}
}
private void throwIfNotAuthenticated() throws SmackException.NotLoggedInException {
if (!connection().isAuthenticated()) {
throw new SmackException.NotLoggedInException();
}
}
}