From 15083fa3b0e4a4500c5ca0e9e4581236e7b609d2 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Mon, 29 Jan 2018 18:37:04 +0100
Subject: [PATCH] Stale devices: Consider date of deviceId publication

---
 .../smackx/omemo/CachingOmemoStore.java       | 23 ++++++++
 .../smackx/omemo/FileBasedOmemoStore.java     | 30 ++++++++---
 .../smackx/omemo/OmemoManager.java            |  8 +++
 .../smackx/omemo/OmemoService.java            | 52 ++++++++++++++++---
 .../jivesoftware/smackx/omemo/OmemoStore.java | 34 ++++++++++--
 .../exceptions/StaleDeviceException.java      | 35 +++++++++++--
 6 files changed, 160 insertions(+), 22 deletions(-)

diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/CachingOmemoStore.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/CachingOmemoStore.java
index cc1c06250..2e7b5cda0 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/CachingOmemoStore.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/CachingOmemoStore.java
@@ -165,6 +165,28 @@ public class CachingOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_Se
         return last;
     }
 
+    @Override
+    public void setDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice, Date date) {
+        getCache(userDevice).lastDeviceIdPublicationDates.put(contactsDevice, date);
+        if (persistent != null) {
+            persistent.setDateOfLastReceivedMessage(userDevice, contactsDevice, date);
+        }
+    }
+
+    @Override
+    public Date getDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice) {
+        Date last = getCache(userDevice).lastDeviceIdPublicationDates.get(contactsDevice);
+
+        if (last == null && persistent != null) {
+            last = persistent.getDateOfLastDeviceIdPublication(userDevice, contactsDevice);
+            if (last != null) {
+                getCache(userDevice).lastDeviceIdPublicationDates.put(contactsDevice, last);
+            }
+        }
+
+        return last;
+    }
+
     @Override
     public void setDateOfLastSignedPreKeyRenewal(OmemoDevice userDevice, Date date) {
         getCache(userDevice).lastRenewalDate = date;
@@ -420,6 +442,7 @@ public class CachingOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_Se
         private final HashMap<BareJid, HashMap<Integer, T_Sess>> sessions = new HashMap<>();
         private final HashMap<OmemoDevice, T_IdKey> identityKeys = new HashMap<>();
         private final HashMap<OmemoDevice, Date> lastMessagesDates = new HashMap<>();
+        private final HashMap<OmemoDevice, Date> lastDeviceIdPublicationDates = new HashMap<>();
         private final HashMap<BareJid, OmemoCachedDeviceList> deviceLists = new HashMap<>();
         private Date lastRenewalDate = null;
     }
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/FileBasedOmemoStore.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/FileBasedOmemoStore.java
index 9adb6f5ba..f44f6d7e0 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/FileBasedOmemoStore.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/FileBasedOmemoStore.java
@@ -105,12 +105,6 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
         }
     }
 
-    @Override
-    public void setDateOfLastReceivedMessage(OmemoDevice userDevice, OmemoDevice contactsDevice, Date date) {
-        File lastMessageReceived = hierarchy.getLastMessageReceivedDatePath(userDevice, contactsDevice);
-        writeLong(lastMessageReceived, date.getTime());
-    }
-
     @Override
     public SortedSet<Integer> localDeviceIdsOf(BareJid localUser) {
         SortedSet<Integer> deviceIds = new TreeSet<>();
@@ -128,6 +122,12 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
         return deviceIds;
     }
 
+    @Override
+    public void setDateOfLastReceivedMessage(OmemoDevice userDevice, OmemoDevice contactsDevice, Date date) {
+        File lastMessageReceived = hierarchy.getLastMessageReceivedDatePath(userDevice, contactsDevice);
+        writeLong(lastMessageReceived, date.getTime());
+    }
+
     @Override
     public Date getDateOfLastReceivedMessage(OmemoDevice userDevice, OmemoDevice contactsDevice) {
         File lastMessageReceived = hierarchy.getLastMessageReceivedDatePath(userDevice, contactsDevice);
@@ -135,6 +135,19 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
         return date != null ? new Date(date) : null;
     }
 
+    @Override
+    public void setDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice, Date date) {
+        File lastDeviceIdPublished = hierarchy.getLastDeviceIdPublicationDatePath(userDevice, contactsDevice);
+        writeLong(lastDeviceIdPublished, date.getTime());
+    }
+
+    @Override
+    public Date getDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice) {
+        File lastDeviceIdPublished = hierarchy.getLastDeviceIdPublicationDatePath(userDevice, contactsDevice);
+        Long date = readLong(lastDeviceIdPublished);
+        return date != null ? new Date(date) : null;
+    }
+
     @Override
     public void setDateOfLastSignedPreKeyRenewal(OmemoDevice userDevice, Date date) {
         File lastSignedPreKeyRenewal = hierarchy.getLastSignedPreKeyRenewal(userDevice);
@@ -753,6 +766,7 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
         static final String IDENTITY_KEY_PAIR = "identityKeyPair";
         static final String PRE_KEYS = "preKeys";
         static final String LAST_MESSAGE_RECEVIED_DATE = "lastMessageReceivedDate";
+        static final String LAST_DEVICEID_PUBLICATION_DATE = "lastDeviceIdPublicationDate";
         static final String SIGNED_PRE_KEYS = "signedPreKeys";
         static final String LAST_SIGNED_PRE_KEY_RENEWAL = "lastSignedPreKeyRenewal";
         static final String SESSION = "session";
@@ -812,6 +826,10 @@ public abstract class FileBasedOmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigP
             return new File(getContactsDir(userDevice, device), LAST_MESSAGE_RECEVIED_DATE);
         }
 
+        File getLastDeviceIdPublicationDatePath(OmemoDevice userDevice, OmemoDevice device) {
+            return new File(getContactsDir(userDevice, device), LAST_DEVICEID_PUBLICATION_DATE);
+        }
+
         File getSignedPreKeysDirectory(OmemoDevice userDevice) {
             return createDirectory(getUserDeviceDirectory(userDevice), SIGNED_PRE_KEYS);
         }
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
index 7af975096..50d3d3068 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoManager.java
@@ -22,6 +22,7 @@ import static org.jivesoftware.smackx.omemo.util.OmemoConstants.PEP_NODE_DEVICE_
 
 import java.security.NoSuchAlgorithmException;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
@@ -245,6 +246,10 @@ public final class OmemoManager extends Manager {
                 throw new SmackException.NotLoggedInException();
             }
 
+            if (getTrustCallback() == null) {
+                throw new IllegalStateException("No TrustCallback set.");
+            }
+
             getOmemoService().init(new LoggedInOmemoManager(this));
             ServiceDiscoveryManager.getInstanceFor(connection()).addFeature(PEP_NODE_DEVICE_LIST_NOTIFY);
         }
@@ -1061,6 +1066,9 @@ public final class OmemoManager extends Manager {
                     final OmemoDeviceListElement_VAxolotl newDeviceList = new OmemoDeviceListElement_VAxolotl(deviceList);
 
                     if (!newDeviceList.copyDeviceIds().equals(receivedDeviceList.copyDeviceIds())) {
+                        LOGGER.log(Level.FINE, "Republish deviceList due to changes:" +
+                                " Received: " + Arrays.toString(receivedDeviceList.copyDeviceIds().toArray()) +
+                                " Published: " + Arrays.toString(newDeviceList.copyDeviceIds().toArray()));
                         Async.go(new Runnable() {
                             @Override
                             public void run() {
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoService.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoService.java
index 82fc14400..70272960a 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoService.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoService.java
@@ -386,16 +386,25 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
             // Ignore stale devices
             if (OmemoConfiguration.getIgnoreStaleDevices()) {
 
-                Date lastActivity = getOmemoStoreBackend().getDateOfLastReceivedMessage(userDevice, contactsDevice);
-                if (lastActivity == null) {
-                    lastActivity = new Date();
-                    getOmemoStoreBackend().setDateOfLastReceivedMessage(userDevice, contactsDevice, lastActivity);
+                Date lastMessageDate = getOmemoStoreBackend().getDateOfLastReceivedMessage(userDevice, contactsDevice);
+                if (lastMessageDate == null) {
+                    lastMessageDate = new Date();
+                    getOmemoStoreBackend().setDateOfLastReceivedMessage(userDevice, contactsDevice, lastMessageDate);
                 }
 
-                if (isStale(userDevice, contactsDevice, lastActivity, OmemoConfiguration.getIgnoreStaleDevicesAfterHours())) {
+                Date lastPublicationDate = getOmemoStoreBackend().getDateOfLastDeviceIdPublication(userDevice, contactsDevice);
+                if (lastPublicationDate == null) {
+                    lastPublicationDate = new Date();
+                    getOmemoStoreBackend().setDateOfLastDeviceIdPublication(userDevice, contactsDevice, lastPublicationDate);
+                }
+
+                boolean stale = isStale(userDevice, contactsDevice, lastPublicationDate, OmemoConfiguration.getIgnoreStaleDevicesAfterHours());
+                stale &= isStale(userDevice, contactsDevice, lastMessageDate, OmemoConfiguration.getIgnoreStaleDevicesAfterHours());
+
+                if (stale) {
                     LOGGER.log(Level.FINE, "Device " + contactsDevice + " seems to be stale (last message received "
-                            + lastActivity + "). Ignore it.");
-                    skippedRecipients.put(contactsDevice, new StaleDeviceException(contactsDevice, lastActivity));
+                            + lastMessageDate + ", last publication of deviceId: " + lastPublicationDate + "). Ignore it.");
+                    skippedRecipients.put(contactsDevice, new StaleDeviceException(contactsDevice, lastMessageDate, lastPublicationDate));
                     continue;
                 }
             }
@@ -860,6 +869,15 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
         return devicesWithSessions;
     }
 
+    /**
+     * Return a set of all devices from the provided set, which trust level is undecided.
+     * A device is also considered undecided, if its fingerprint cannot be loaded.
+     *
+     * @param userDevice our OmemoDevice
+     * @param callback OmemoTrustCallback to query the trust decisions from
+     * @param devices set of OmemoDevices
+     * @return set of OmemoDevices which contains all devices from the set devices, which are undecided
+     */
     private Set<OmemoDevice> getUndecidedDevices(OmemoDevice userDevice, OmemoTrustCallback callback, Set<OmemoDevice> devices) {
         Set<OmemoDevice> undecidedDevices = new HashSet<>();
 
@@ -883,6 +901,15 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
         return undecidedDevices;
     }
 
+    /**
+     * Return a set of all devices from the provided set, which are untrusted.
+     * A device is also considered untrusted, if its fingerprint cannot be loaded.
+     *
+     * @param userDevice our own OmemoDevice
+     * @param trustCallback OmemoTrustCallback to query trust decisions from
+     * @param devices set of OmemoDevices
+     * @return set of OmemoDevices from devices, which contains all devices which are untrusted
+     */
     private Set<OmemoDevice> getUntrustedDeviced(OmemoDevice userDevice, OmemoTrustCallback trustCallback, Set<OmemoDevice> devices) {
         Set<OmemoDevice> untrustedDevices = new HashSet<>();
 
@@ -1009,13 +1036,22 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
         for (int deviceId : deviceList.getActiveDevices()) {
             OmemoDevice device = new OmemoDevice(contact, deviceId);
 
+            Date lastDeviceIdPublication = getOmemoStoreBackend().getDateOfLastDeviceIdPublication(userDevice, device);
+            if (lastDeviceIdPublication == null) {
+                lastDeviceIdPublication = new Date();
+                getOmemoStoreBackend().setDateOfLastDeviceIdPublication(userDevice, device, lastDeviceIdPublication);
+            }
+
             Date lastMessageReceived = getOmemoStoreBackend().getDateOfLastReceivedMessage(userDevice, device);
             if (lastMessageReceived == null) {
                 lastMessageReceived = new Date();
                 getOmemoStoreBackend().setDateOfLastReceivedMessage(userDevice, device, lastMessageReceived);
             }
 
-            if (isStale(userDevice, device, lastMessageReceived, maxAgeHours)) {
+            boolean stale = isStale(userDevice, device, lastDeviceIdPublication, maxAgeHours);
+            stale &= isStale(userDevice, device, lastMessageReceived, maxAgeHours);
+
+            if (stale) {
                 deviceList.addInactiveDevice(deviceId);
             }
         }
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoStore.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoStore.java
index ec44322e0..dde8a5df9 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoStore.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoStore.java
@@ -108,11 +108,19 @@ public abstract class OmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_
             cached = new OmemoCachedDeviceList();
         }
 
-        if (list != null) {
-            cached.merge(list.getDeviceIds());
-            storeCachedDeviceList(userDevice, contact, cached);
+        if (list == null) {
+            return cached;
         }
 
+        for (int devId : list.getDeviceIds()) {
+            if (!cached.contains(devId)) {
+                setDateOfLastDeviceIdPublication(userDevice, new OmemoDevice(contact, devId), new Date());
+            }
+        }
+
+        cached.merge(list.getDeviceIds());
+        storeCachedDeviceList(userDevice, contact, cached);
+
         return cached;
     }
 
@@ -300,6 +308,26 @@ public abstract class OmemoStore<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey, T_
      */
     public abstract Date getDateOfLastReceivedMessage(OmemoDevice userDevice, OmemoDevice contactsDevice);
 
+    /**
+     * Set the date of the last time the deviceId was published. This method only gets called, when the deviceId
+     * was inactive/non-existent before it was published.
+     *
+     * @param userDevice our OmemoDevice
+     * @param contactsDevice OmemoDevice in question
+     * @param date date of the last publication after not being published
+     */
+    public abstract void setDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice, Date date);
+
+    /**
+     * Return the date of the last time the deviceId was published after previously being not published.
+     * (Point in time, where the status of the deviceId changed from inactive/non-existent to active).
+     *
+     * @param userDevice our OmemoDevice
+     * @param contactsDevice OmemoDevice in question
+     * @return date of the last publication after not being published
+     */
+    public abstract Date getDateOfLastDeviceIdPublication(OmemoDevice userDevice, OmemoDevice contactsDevice);
+
     /**
      * Set the date of the last time the signed preKey was renewed.
      *
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/exceptions/StaleDeviceException.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/exceptions/StaleDeviceException.java
index 2d51a94f2..be2c31e89 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/exceptions/StaleDeviceException.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/exceptions/StaleDeviceException.java
@@ -24,17 +24,42 @@ public class StaleDeviceException extends Exception {
     private static final long serialVersionUID = 1L;
 
     private final OmemoDevice device;
-    private final Date lastActivity;
+    private final Date lastMessageDate;
+    private final Date lastDeviceIdPublication;
 
-    public StaleDeviceException(OmemoDevice device, Date lastActivity) {
+    /**
+     * This exception gets thrown if a message cannot be encrypted for a device due to the device being inactive for too long (stale).
+     *
+     * @param device OmemoDevice.
+     * @param lastMessageDate
+     * @param lastDeviceIdPublicationDate
+     */
+    public StaleDeviceException(OmemoDevice device, Date lastMessageDate, Date lastDeviceIdPublicationDate) {
         this.device = device;
-        this.lastActivity = lastActivity;
+        this.lastMessageDate = lastMessageDate;
+        this.lastDeviceIdPublication = lastDeviceIdPublicationDate;
     }
 
-    public Date getLastActivity() {
-        return lastActivity;
+    /**
+     * Return the date on which the last OMEMO message sent from the device was received.
+     * @return last messages date
+     */
+    public Date getLastMessageDate() {
+        return lastMessageDate;
     }
 
+    /**
+     * Return the date of the last time the deviceId was republished after being inactive/non-existent before.
+     * @return date of last deviceId (re)publication.
+     */
+    public Date getLastDeviceIdPublicationDate() {
+        return lastDeviceIdPublication;
+    }
+
+    /**
+     * Return the stale OMEMO device.
+     * @return stale device
+     */
     public OmemoDevice getDevice() {
         return device;
     }