Merge pull request #273 from vanitasvitae/omemoMessageCounter

OMEMO: Add Message Counter Logic
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Florian Schmaus 2018-10-10 15:01:52 +02:00 committed by GitHub
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10 changed files with 269 additions and 80 deletions

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@ -0,0 +1,72 @@
/**
*
* Copyright 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.omemo;
import static junit.framework.TestCase.assertEquals;
import static junit.framework.TestCase.assertFalse;
import static junit.framework.TestCase.assertTrue;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smackx.omemo.exceptions.CryptoFailedException;
import org.jivesoftware.smackx.omemo.exceptions.ReadOnlyDeviceException;
import org.jivesoftware.smackx.omemo.exceptions.UndecidedOmemoIdentityException;
import org.igniterealtime.smack.inttest.SmackIntegrationTest;
import org.igniterealtime.smack.inttest.SmackIntegrationTestEnvironment;
import org.igniterealtime.smack.inttest.TestNotPossibleException;
public class ReadOnlyDeviceIntegrationTest extends AbstractTwoUsersOmemoIntegrationTest {
public ReadOnlyDeviceIntegrationTest(SmackIntegrationTestEnvironment environment) throws XMPPException.XMPPErrorException, SmackException.NotConnectedException, InterruptedException, SmackException.NoResponseException, TestNotPossibleException {
super(environment);
}
@SmackIntegrationTest
public void test() throws InterruptedException, SmackException.NoResponseException, SmackException.NotLoggedInException, SmackException.NotConnectedException, CryptoFailedException, UndecidedOmemoIdentityException {
boolean prevIgnoreReadOnlyConf = OmemoConfiguration.getIgnoreReadOnlyDevices();
int prevMaxMessageCounter = OmemoConfiguration.getMaxReadOnlyMessageCount();
OmemoConfiguration.setIgnoreReadOnlyDevices(true);
// Set the maxReadOnlyMessageCount to ridiculously low threshold of 5.
// This means that Alice will be able to encrypt 5 messages for Bob, while the 6th will not be encrypted for Bob.
OmemoConfiguration.setMaxReadOnlyMessageCount(5);
// Reset counter to begin test
alice.getOmemoService().getOmemoStoreBackend().storeOmemoMessageCounter(alice.getOwnDevice(), bob.getOwnDevice(), 0);
// Since the max threshold is 5, we must be able to encrypt 5 messages for Bob.
for (int i = 0; i < 5; i++) {
assertEquals(i, alice.getOmemoService().getOmemoStoreBackend().loadOmemoMessageCounter(alice.getOwnDevice(), bob.getOwnDevice()));
OmemoMessage.Sent message = alice.encrypt(bob.getOwnJid(), "Hello World!");
assertFalse(message.getSkippedDevices().containsKey(bob.getOwnDevice()));
}
// Now the message counter must be too high and Bobs device must be skipped.
OmemoMessage.Sent message = alice.encrypt(bob.getOwnJid(), "Hello World!");
Throwable exception = message.getSkippedDevices().get(bob.getOwnDevice());
assertTrue(exception instanceof ReadOnlyDeviceException);
assertEquals(bob.getOwnDevice(), ((ReadOnlyDeviceException) exception).getDevice());
// Reset the message counter
alice.getOmemoService().getOmemoStoreBackend().storeOmemoMessageCounter(alice.getOwnDevice(), bob.getOwnDevice(), 0);
// Reset the configuration to previous values
OmemoConfiguration.setMaxReadOnlyMessageCount(prevMaxMessageCounter);
OmemoConfiguration.setIgnoreReadOnlyDevices(prevIgnoreReadOnlyConf);
}
}

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@ -140,6 +140,30 @@ public class CachingOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_Se
}
}
@Override
public void storeOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice, int counter) {
getCache(userDevice).messageCounters.put(contactsDevice, counter);
if (persistent != null) {
persistent.storeOmemoMessageCounter(userDevice, contactsDevice, counter);
}
}
@Override
public int loadOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice) {
Integer counter = getCache(userDevice).messageCounters.get(contactsDevice);
if (counter == null && persistent != null) {
counter = persistent.loadOmemoMessageCounter(userDevice, contactsDevice);
}
if (counter == null) {
counter = 0;
}
getCache(userDevice).messageCounters.put(contactsDevice, counter);
return counter;
}
@Override
public void setDateOfLastReceivedMessage(OmemoDevice userDevice, OmemoDevice from, Date date) {
getCache(userDevice).lastMessagesDates.put(from, date);
@ -442,5 +466,6 @@ public class CachingOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_Se
private final HashMap<OmemoDevice, Date> lastDeviceIdPublicationDates = new HashMap<>();
private final HashMap<BareJid, OmemoCachedDeviceList> deviceLists = new HashMap<>();
private Date lastRenewalDate = null;
private final HashMap<OmemoDevice, Integer> messageCounters = new HashMap<>();
}
}

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@ -24,6 +24,7 @@ import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.util.Collections;
import java.util.Date;
import java.util.HashMap;
import java.util.HashSet;
@ -353,6 +354,24 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
return session.exists();
}
@Override
public void storeOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice, int counter) {
File messageCounterFile = hierarchy.getDevicesMessageCounterPath(userDevice, contactsDevice);
writeIntegers(messageCounterFile, Collections.singleton(counter));
}
@Override
public int loadOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice) {
File messageCounterFile = hierarchy.getDevicesMessageCounterPath(userDevice, contactsDevice);
Set<Integer> integers = readIntegers(messageCounterFile);
if (integers == null || integers.isEmpty()) {
return 0;
}
return integers.iterator().next();
}
@Override
public OmemoCachedDeviceList loadCachedDeviceList(OmemoDevice userDevice, BareJid contact) {
OmemoCachedDeviceList cachedDeviceList = new OmemoCachedDeviceList();
@ -732,6 +751,7 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
static final String SESSION = "session";
static final String DEVICE_LIST_ACTIVE = "activeDevices";
static final String DEVICE_LIST_INAVTIVE = "inactiveDevices";
static final String MESSAGE_COUNTER = "messageCounter";
File basePath;
@ -815,6 +835,10 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
return new File(getContactsDir(userDevice, contact), DEVICE_LIST_INAVTIVE);
}
File getDevicesMessageCounterPath(OmemoDevice userDevice, OmemoDevice otherDevice) {
return new File(getContactsDir(userDevice, otherDevice), MESSAGE_COUNTER);
}
private static File createFile(File f) throws IOException {
File p = f.getParentFile();
createDirectory(p);

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@ -23,31 +23,56 @@ package org.jivesoftware.smackx.omemo;
*/
public final class OmemoConfiguration {
private static boolean IGNORE_READ_ONLY_DEVICES = true;
private static int MAX_READ_ONLY_MESSAGE_COUNT = 400;
/**
* Ignore own other stale devices that we did not receive a message from for a period of time.
* Ignoring means do not encrypt messages for them. This helps to mitigate stale devices that threaten
* forward secrecy by never advancing ratchets.
* Set to true, in order to ignore read-only devices.
*
* @param ignore ignore read-only devices
* @see <a href="example.com">Blog Post explaining the danger of read-only devices. TODO: Add URL </a>
*/
private static boolean IGNORE_STALE_DEVICES = true;
private static int IGNORE_STALE_DEVICE_AFTER_HOURS = 24 * 7; //One week
public static void setIgnoreStaleDevices(boolean ignore) {
IGNORE_STALE_DEVICES = ignore;
public static void setIgnoreReadOnlyDevices(boolean ignore) {
IGNORE_READ_ONLY_DEVICES = ignore;
}
public static boolean getIgnoreStaleDevices() {
return IGNORE_STALE_DEVICES;
/**
* Return true, if the client should stop encrypting messages to a read-only device.
*
* @return true if read-only devices should get ignored after a certain amount of unanswered messages.
* @see <a href="example.com">Blog Post explaining the danger of read-only devices. TODO: Add URL </a>
*/
public static boolean getIgnoreReadOnlyDevices() {
return IGNORE_READ_ONLY_DEVICES;
}
public static void setIgnoreStaleDevicesAfterHours(int hours) {
if (hours <= 0) {
throw new IllegalArgumentException("Hours must be greater than 0.");
/**
* Set the maximum amount of messages that the client is allowed to send to a read-only device without getting a
* response. Once the message counter of a device reaches that value, the client will stop encrypting messages for
* the device (given that {@link #getIgnoreReadOnlyDevices()} is true).
* This threshold is used to prevent read-only devices from weakening forward secrecy.
*
* @param maxReadOnlyMessageCount maximum number of allowed messages to a read-only device.
* @see <a href="example.com">Blog Post explaining the danger of read-only devices. TODO: Add URL </a>
*/
public static void setMaxReadOnlyMessageCount(int maxReadOnlyMessageCount) {
if (maxReadOnlyMessageCount <= 0) {
throw new IllegalArgumentException("maxReadOnlyMessageCount MUST be greater than 0.");
}
IGNORE_STALE_DEVICE_AFTER_HOURS = hours;
MAX_READ_ONLY_MESSAGE_COUNT = maxReadOnlyMessageCount;
}
public static int getIgnoreStaleDevicesAfterHours() {
return IGNORE_STALE_DEVICE_AFTER_HOURS;
/**
* Get the maximum amount of messages that the client is allowed to send to a read-only device without getting a
* response. Once the message counter of a device reaches that value, the client will stop encrypting messages for
* the device (given that {@link #getIgnoreReadOnlyDevices()} is true).
* This threshold is used to prevent read-only devices from weakening forward secrecy.
*
* @return maximum number of allowed messages to a read-only device.
* @see <a href="example.com">Blog Post explaining the danger of read-only devices. TODO: Add URL </a>
*/
public static int getMaxReadOnlyMessageCount() {
return MAX_READ_ONLY_MESSAGE_COUNT;
}
/**

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@ -43,7 +43,6 @@ import javax.crypto.NoSuchPaddingException;
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.packet.Stanza;
import org.jivesoftware.smack.packet.StanzaError;
@ -62,7 +61,7 @@ import org.jivesoftware.smackx.omemo.exceptions.CorruptedOmemoKeyException;
import org.jivesoftware.smackx.omemo.exceptions.CryptoFailedException;
import org.jivesoftware.smackx.omemo.exceptions.NoIdentityKeyException;
import org.jivesoftware.smackx.omemo.exceptions.NoRawSessionException;
import org.jivesoftware.smackx.omemo.exceptions.StaleDeviceException;
import org.jivesoftware.smackx.omemo.exceptions.ReadOnlyDeviceException;
import org.jivesoftware.smackx.omemo.exceptions.UndecidedOmemoIdentityException;
import org.jivesoftware.smackx.omemo.exceptions.UntrustedOmemoIdentityException;
import org.jivesoftware.smackx.omemo.internal.CipherAndAuthTag;
@ -323,6 +322,8 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
throw new AssertionError("We MUST have an identityKey for " + contactsDevice + " since we built a session." + e);
}
// Note: We don't need to update our message counter for a ratchet update message.
return builder.finish();
}
@ -386,28 +387,20 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
}
}
// Ignore own stale devices
if (contactsDevice.getJid().equals(userDevice.getJid()) && OmemoConfiguration.getIgnoreStaleDevices()) {
int messageCounter = omemoStore.loadOmemoMessageCounter(userDevice, contactsDevice);
Date lastMessageDate = getOmemoStoreBackend().getDateOfLastReceivedMessage(userDevice, contactsDevice);
if (lastMessageDate == null) {
lastMessageDate = new Date();
getOmemoStoreBackend().setDateOfLastReceivedMessage(userDevice, contactsDevice, lastMessageDate);
}
// Ignore read-only devices
if (OmemoConfiguration.getIgnoreReadOnlyDevices()) {
Date lastPublicationDate = getOmemoStoreBackend().getDateOfLastDeviceIdPublication(userDevice, contactsDevice);
if (lastPublicationDate == null) {
lastPublicationDate = new Date();
getOmemoStoreBackend().setDateOfLastDeviceIdPublication(userDevice, contactsDevice, lastPublicationDate);
}
boolean readOnly = messageCounter >= OmemoConfiguration.getMaxReadOnlyMessageCount();
boolean stale = isStale(userDevice, contactsDevice, lastPublicationDate, OmemoConfiguration.getIgnoreStaleDevicesAfterHours());
stale &= isStale(userDevice, contactsDevice, lastMessageDate, OmemoConfiguration.getIgnoreStaleDevicesAfterHours());
if (readOnly) {
LOGGER.log(Level.FINE, "Device " + contactsDevice + " seems to be read-only (We sent "
+ messageCounter + " messages without getting a reply back (max allowed is " +
OmemoConfiguration.getMaxReadOnlyMessageCount() + "). Ignoring the device.");
skippedRecipients.put(contactsDevice, new ReadOnlyDeviceException(contactsDevice));
if (stale) {
LOGGER.log(Level.FINE, "Device " + contactsDevice + " seems to be stale (last message received "
+ lastMessageDate + ", last publication of deviceId: " + lastPublicationDate + "). Ignore it.");
skippedRecipients.put(contactsDevice, new StaleDeviceException(contactsDevice, lastMessageDate, lastPublicationDate));
// Skip this device and handle next device
continue;
}
}
@ -428,6 +421,10 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
LOGGER.log(Level.WARNING, "Device " + contactsDevice + " is untrusted. Message is not encrypted for it.");
skippedRecipients.put(contactsDevice, e);
}
// Increment the message counter of the device
omemoStore.storeOmemoMessageCounter(userDevice, contactsDevice,
messageCounter + 1);
}
OmemoElement element = builder.finish();
@ -466,6 +463,9 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
throw new AssertionError("Cannot retrieve OmemoFingerprint of sender although decryption was successful: " + e);
}
// Reset the message counter.
omemoStore.storeOmemoMessageCounter(manager.getOwnDevice(), senderDevice, 0);
if (omemoElement.isMessageElement()) {
// Use symmetric message key to decrypt message payload.
String plaintext = OmemoRatchet.decryptMessageElement(omemoElement, cipherAndAuthTag);
@ -1009,24 +1009,6 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
return removeStaleDevicesFromDeviceList(userDevice, userDevice.getJid(), deviceList, maxAgeHours);
}
/**
* Return a copy of the contactsDeviceList, but with stale devices marked as inactive.
* Never mark our own device as stale.
* This method ignores {@link OmemoConfiguration#getIgnoreStaleDevices()}!
*
* In this case, a stale device is one of our devices, from which we haven't received an OMEMO message from
* for more than {@link OmemoConfiguration#IGNORE_STALE_DEVICE_AFTER_HOURS} hours.
*
* @param userDevice our OmemoDevice
* @param contact subjects BareJid
* @param contactsDeviceList subjects deviceList
* @return
*/
private OmemoCachedDeviceList ignoreStaleDevices(OmemoDevice userDevice, BareJid contact, OmemoCachedDeviceList contactsDeviceList) {
int maxAgeHours = OmemoConfiguration.getIgnoreStaleDevicesAfterHours();
return removeStaleDevicesFromDeviceList(userDevice, contact, contactsDeviceList, maxAgeHours);
}
/**
* Return a copy of the given deviceList of user contact, but with stale devices marked as inactive.
* Never mark our own device as stale. If we haven't yet received a message from a device, store the current date
@ -1086,12 +1068,14 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
}
/**
* Determine, whether another one of *our* devices is stale or not.
*
* @param userDevice
* @param subject
* @param lastReceipt
* @param maxAgeHours
* @return
* @param userDevice our omemoDevice
* @param subject another one of our devices
* @param lastReceipt date of last received message from that device
* @param maxAgeHours threshold
*
* @return staleness
*/
static boolean isStale(OmemoDevice userDevice, OmemoDevice subject, Date lastReceipt, int maxAgeHours) {
if (userDevice.equals(subject)) {

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@ -290,6 +290,27 @@ public abstract class OmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_
*/
public abstract void removeOmemoIdentityKey(OmemoDevice userDevice, OmemoDevice contactsDevice);
/**
* Store the number of messages we sent to a device since we last received a message back.
* This counter gets reset to 0 whenever we receive a message from the contacts device.
*
* @param userDevice our omemoDevice.
* @param contactsDevice device of which we want to set the message counter.
* @param counter counter value.
*/
public abstract void storeOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice, int counter);
/**
* Return the current value of the message counter.
* This counter represents the number of message we sent to the contactsDevice without getting a reply back.
* The default value for this counter is 0.
*
* @param userDevice our omemoDevice
* @param contactsDevice device of which we want to get the message counter.
* @return counter value.
*/
public abstract int loadOmemoMessageCounter(OmemoDevice userDevice, OmemoDevice contactsDevice);
/**
* Set the date of the last message that was received from a device.
*

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@ -0,0 +1,52 @@
/**
*
* Copyright 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.omemo.exceptions;
import org.jivesoftware.smackx.omemo.OmemoConfiguration;
import org.jivesoftware.smackx.omemo.internal.OmemoDevice;
/**
* Exception that signals, that a device is considered read-only.
* Read-only devices are devices that receive OMEMO messages, but do not send any.
* Those devices are weakening forward secrecy. For that reason, read-only devices are ignored after n messages have
* been sent without getting a reply back.
*/
public class ReadOnlyDeviceException extends Exception {
private static final long serialVersionUID = 1L;
private final OmemoDevice device;
/**
* Constructor.
* We do not need to hand over the current value of the message counter, as that value will always be equal to
* {@link OmemoConfiguration#getMaxReadOnlyMessageCount()}. Therefore providing the {@link OmemoDevice} should be
* enough.
*
* @param device device which is considered read-only.
*/
public ReadOnlyDeviceException(OmemoDevice device) {
this.device = device;
}
/**
* Return the device in question.
* @return device
*/
public OmemoDevice getDevice() {
return device;
}
}

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@ -52,20 +52,6 @@ public class OmemoConfigurationTest {
// Expected.
}
// Ignore stale device
OmemoConfiguration.setIgnoreStaleDevices(false);
assertEquals(false, OmemoConfiguration.getIgnoreStaleDevices());
OmemoConfiguration.setIgnoreStaleDevices(true);
assertEquals(true, OmemoConfiguration.getIgnoreStaleDevices());
OmemoConfiguration.setIgnoreStaleDevicesAfterHours(44);
assertEquals(44, OmemoConfiguration.getIgnoreStaleDevicesAfterHours());
try {
OmemoConfiguration.setIgnoreStaleDevicesAfterHours(-5);
TestCase.fail("OmemoConfiguration.setIgnoreStaleDevicesAfterHours should not accept values <= 0.");
} catch (IllegalArgumentException e) {
// Expected
}
// Renew signedPreKeys
OmemoConfiguration.setRenewOldSignedPreKeys(false);
assertEquals(false, OmemoConfiguration.getRenewOldSignedPreKeys());

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@ -32,7 +32,6 @@ import org.jxmpp.stringprep.XmppStringprepException;
public class OmemoServiceTest extends SmackTestSuite {
private static final long ONE_HOUR = 1000L * 60 * 60;
private static final int IGNORE_STALE = OmemoConfiguration.getIgnoreStaleDevicesAfterHours();
private static final int DELETE_STALE = OmemoConfiguration.getDeleteStaleDevicesAfterHours();
@Test(expected = IllegalStateException.class)
@ -55,15 +54,9 @@ public class OmemoServiceTest extends SmackTestSuite {
OmemoDevice other = new OmemoDevice(JidCreate.bareFrom("bob@builder.tv"), 444);
Date now = new Date();
Date ignoreMe = new Date(now.getTime() - ((IGNORE_STALE + 1) * ONE_HOUR));
Date deleteMe = new Date(now.getTime() - ((DELETE_STALE + 1) * ONE_HOUR));
Date imFine = new Date(now.getTime() - ONE_HOUR);
// One hour "old" devices are (probably) not not stale
assertFalse(OmemoService.isStale(user, other, imFine, IGNORE_STALE));
// Devices one hour "older" than max ages are stale
assertTrue(OmemoService.isStale(user, other, ignoreMe, IGNORE_STALE));
assertTrue(OmemoService.isStale(user, other, deleteMe, DELETE_STALE));
// Own device is never stale, no matter how old

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@ -314,6 +314,13 @@ public abstract class OmemoStoreTest<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey
assertNull(session);
}
@Test
public void loadStoreMessageCounterTest() {
assertEquals(0, store.loadOmemoMessageCounter(alice, bob));
store.storeOmemoMessageCounter(alice, bob, 20);
assertEquals(20, store.loadOmemoMessageCounter(alice, bob));
}
@Test
public void getFingerprint() throws IOException, CorruptedOmemoKeyException {
assertNull("Method must return null for a non-existent fingerprint.", store.getFingerprint(alice));