From 38d9d96d1f36b5124bf211ce8cbce5446bf4c542 Mon Sep 17 00:00:00 2001
From: Paul Schaub <vanitasvitae@fsfe.org>
Date: Wed, 24 Jan 2018 14:17:22 +0100
Subject: [PATCH] Use set instead of list for handling OmemoDevice

---
 .../smackx/omemo/OmemoManager.java            | 19 +++---
 .../smackx/omemo/OmemoMessage.java            | 10 +--
 .../smackx/omemo/OmemoService.java            | 67 ++++++++++---------
 3 files changed, 50 insertions(+), 46 deletions(-)

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 9011fd0e9..7af975096 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
@@ -26,6 +26,7 @@ import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
+import java.util.Set;
 import java.util.SortedSet;
 import java.util.TreeMap;
 import java.util.WeakHashMap;
@@ -270,15 +271,15 @@ public final class OmemoManager extends Manager {
     }
 
     /**
-     * Return a list of all OMEMO capable devices of a contact.
+     * Return a set of all OMEMO capable devices of a contact.
      * Note, that this method does not explicitly refresh the device list of the contact, so it might be outdated.
      * @see #requestDeviceListUpdateFor(BareJid)
-     * @param contact contact we want to get a list of device of.
-     * @return list of known devices of that contact.
+     * @param contact contact we want to get a set of device of.
+     * @return set of known devices of that contact.
      */
-    public List<OmemoDevice> getDevicesOf(BareJid contact) {
+    public Set<OmemoDevice> getDevicesOf(BareJid contact) {
         OmemoCachedDeviceList list = getOmemoService().getOmemoStoreBackend().loadCachedDeviceList(getOwnDevice(), contact);
-        ArrayList<OmemoDevice> devices = new ArrayList<>();
+        HashSet<OmemoDevice> devices = new HashSet<>();
 
         for (int deviceId : list.getActiveDevices()) {
             devices.add(new OmemoDevice(contact, deviceId));
@@ -307,7 +308,7 @@ public final class OmemoManager extends Manager {
             SmackException.NoResponseException, SmackException.NotLoggedInException
     {
         synchronized (LOCK) {
-            ArrayList<BareJid> recipients = new ArrayList<>();
+            Set<BareJid> recipients = new HashSet<>();
             recipients.add(recipient);
             return encrypt(recipients, message);
         }
@@ -326,14 +327,14 @@ public final class OmemoManager extends Manager {
      * @throws SmackException.NoResponseException
      * @throws SmackException.NotLoggedInException
      */
-    public OmemoMessage.Sent encrypt(ArrayList<BareJid> recipients, String message)
+    public OmemoMessage.Sent encrypt(Set<BareJid> recipients, String message)
             throws CryptoFailedException, UndecidedOmemoIdentityException,
             InterruptedException, SmackException.NotConnectedException,
             SmackException.NoResponseException, SmackException.NotLoggedInException
     {
         synchronized (LOCK) {
             LoggedInOmemoManager guard = new LoggedInOmemoManager(this);
-            List<OmemoDevice> devices = getDevicesOf(getOwnJid());
+            Set<OmemoDevice> devices = getDevicesOf(getOwnJid());
             for (BareJid recipient : recipients) {
                 devices.addAll(getDevicesOf(recipient));
             }
@@ -367,7 +368,7 @@ public final class OmemoManager extends Manager {
                 throw new NoOmemoSupportException();
             }
 
-            ArrayList<BareJid> recipients = new ArrayList<>();
+            Set<BareJid> recipients = new HashSet<>();
 
             for (EntityFullJid e : muc.getOccupants()) {
                 recipients.add(muc.getOccupant(e).getJid().asBareJid());
diff --git a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoMessage.java b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoMessage.java
index af046e93c..823222d7c 100644
--- a/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoMessage.java
+++ b/smack-omemo/src/main/java/org/jivesoftware/smackx/omemo/OmemoMessage.java
@@ -20,9 +20,9 @@ import static org.jivesoftware.smackx.omemo.util.OmemoConstants.BODY_OMEMO_HINT;
 import static org.jivesoftware.smackx.omemo.util.OmemoConstants.OMEMO;
 import static org.jivesoftware.smackx.omemo.util.OmemoConstants.OMEMO_NAMESPACE_V_AXOLOTL;
 
-import java.util.ArrayList;
 import java.util.HashMap;
-import java.util.List;
+import java.util.HashSet;
+import java.util.Set;
 
 import org.jivesoftware.smack.packet.Message;
 import org.jivesoftware.smackx.eme.element.ExplicitMessageEncryptionElement;
@@ -74,7 +74,7 @@ public class OmemoMessage {
      * Outgoing OMEMO message.
      */
     public static class Sent extends OmemoMessage {
-        private final ArrayList<OmemoDevice> intendedDevices = new ArrayList<>();
+        private final Set<OmemoDevice> intendedDevices = new HashSet<>();
         private final HashMap<OmemoDevice, Throwable> skippedDevices = new HashMap<>();
 
         /**
@@ -86,7 +86,7 @@ public class OmemoMessage {
          * @param skippedDevices devices which were skipped during encryption process because encryption
          *                       failed for some reason
          */
-        Sent(OmemoElement element, byte[] key, byte[] iv, List<OmemoDevice> intendedDevices, HashMap<OmemoDevice, Throwable> skippedDevices) {
+        Sent(OmemoElement element, byte[] key, byte[] iv, Set<OmemoDevice> intendedDevices, HashMap<OmemoDevice, Throwable> skippedDevices) {
             super(element, key, iv);
             this.intendedDevices.addAll(intendedDevices);
             this.skippedDevices.putAll(skippedDevices);
@@ -96,7 +96,7 @@ public class OmemoMessage {
          * Return a list of all devices the sender originally intended to encrypt the message for.
          * @return list of intended recipients.
          */
-        public List<OmemoDevice> getIntendedDevices() {
+        public Set<OmemoDevice> getIntendedDevices() {
             return intendedDevices;
         }
 
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 9e9f3c8a0..82fc14400 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
@@ -30,6 +30,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.Date;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Random;
 import java.util.Set;
@@ -326,7 +327,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
      * Encrypt a message with a messageKey and an IV and create an OmemoMessage from it.
      *
      * @param managerGuard authenticated OmemoManager
-     * @param contactsDevices list of recipient OmemoDevices
+     * @param contactsDevices set of recipient OmemoDevices
      * @param messageKey AES key to encrypt the message
      * @param iv iv to be used with the messageKey
      * @return OmemoMessage object which contains the OmemoElement and some information.
@@ -338,7 +339,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
      * @throws CryptoFailedException if we are lacking some crypto primitives
      */
     private OmemoMessage.Sent encrypt(OmemoManager.LoggedInOmemoManager managerGuard,
-                                      List<OmemoDevice> contactsDevices,
+                                      Set<OmemoDevice> contactsDevices,
                                       byte[] messageKey,
                                       byte[] iv,
                                       String message)
@@ -353,7 +354,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
 
         buildMissingSessionsWithDevices(manager.getConnection(), userDevice, contactsDevices);
 
-        ArrayList<OmemoDevice> undecidedDevices = getUndecidedDevices(userDevice, manager.getTrustCallback(), contactsDevices);
+        Set<OmemoDevice> undecidedDevices = getUndecidedDevices(userDevice, manager.getTrustCallback(), contactsDevices);
         if (!undecidedDevices.isEmpty()) {
             throw new UndecidedOmemoIdentityException(undecidedDevices);
         }
@@ -472,7 +473,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
      * @see <a href="https://xmpp.org/extensions/xep-0384.html#usecases-keysend">XEP-0384: Sending a key</a>.
      *
      * @param managerGuard Initialized OmemoManager.
-     * @param contactsDevices recipient devices.
+     * @param contactsDevices set of recipient devices.
      * @param key AES-Key to be transported.
      * @param iv initialization vector to be used with the key.
      * @return KeyTransportElement
@@ -484,7 +485,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
      * @throws SmackException.NoResponseException
      */
     OmemoMessage.Sent createKeyTransportElement(OmemoManager.LoggedInOmemoManager managerGuard,
-                                                List<OmemoDevice> contactsDevices,
+                                                Set<OmemoDevice> contactsDevices,
                                                 byte[] key,
                                                 byte[] iv)
             throws InterruptedException, UndecidedOmemoIdentityException, CryptoFailedException,
@@ -494,11 +495,13 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
     }
 
     /**
+     * Create an OmemoMessage.
+     *
+     * @param managerGuard initialized OmemoManager
+     * @param contactsDevices set of recipient devices
+     * @param message message we want to send
+     * @return encrypted OmemoMessage
      *
-     * @param managerGuard
-     * @param contactsDevices
-     * @param message
-     * @return
      * @throws InterruptedException
      * @throws UndecidedOmemoIdentityException if the list of recipient devices contains an undecided device.
      * @throws CryptoFailedException if we are lacking some cryptographic algorithms
@@ -506,7 +509,7 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
      * @throws SmackException.NoResponseException
      */
     OmemoMessage.Sent createOmemoMessage(OmemoManager.LoggedInOmemoManager managerGuard,
-                                         List<OmemoDevice> contactsDevices,
+                                         Set<OmemoDevice> contactsDevices,
                                          String message)
             throws InterruptedException, UndecidedOmemoIdentityException, CryptoFailedException,
             SmackException.NotConnectedException, SmackException.NoResponseException
@@ -764,24 +767,24 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
 
     /**
      * Build OMEMO sessions with all devices of the contact, we haven't had sessions with before.
-     * This method returns a list of OmemoDevices. This list contains all devices, with which we either had sessions
+     * This method returns a set of OmemoDevices. This set contains all devices, with which we either had sessions
      * before, plus those devices with which we just built sessions.
      *
      * @param connection authenticated XMPP connection.
      * @param userDevice our OmemoDevice
      * @param contact the BareJid of the contact with whom we want to build sessions with.
-     * @return list of devices with a session.
+     * @return set of devices with a session.
      * @throws SmackException.NotConnectedException
      * @throws InterruptedException
      * @throws SmackException.NoResponseException
      */
-    private ArrayList<OmemoDevice> buildMissingSessionsWithContact(XMPPConnection connection,
+    private Set<OmemoDevice> buildMissingSessionsWithContact(XMPPConnection connection,
                                                                    OmemoDevice userDevice,
                                                                    BareJid contact)
             throws SmackException.NotConnectedException, InterruptedException, SmackException.NoResponseException
     {
         OmemoCachedDeviceList contactsDeviceIds = getOmemoStoreBackend().loadCachedDeviceList(userDevice, contact);
-        ArrayList<OmemoDevice> contactsDevices = new ArrayList<>();
+        Set<OmemoDevice> contactsDevices = new HashSet<>();
         for (int deviceId : contactsDeviceIds.getActiveDevices()) {
             contactsDevices.add(new OmemoDevice(contact, deviceId));
         }
@@ -790,22 +793,22 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
     }
 
     /**
-     * Build sessions with all devices from the list, we don't have a session with yet.
-     * Return the list of all devices we have a session with afterwards.
+     * Build sessions with all devices from the set, we don't have a session with yet.
+     * Return the set of all devices we have a session with afterwards.
      * @param connection authenticated XMPP connection
      * @param userDevice our OmemoDevice
-     * @param devices list of devices we may want to build a session with if necessary
-     * @return list of all devices with sessions
+     * @param devices set of devices we may want to build a session with if necessary
+     * @return set of all devices with sessions
      *
      * @throws SmackException.NotConnectedException
      * @throws InterruptedException
      * @throws SmackException.NoResponseException
      */
-    private ArrayList<OmemoDevice> buildMissingSessionsWithDevices(XMPPConnection connection,
+    private Set<OmemoDevice> buildMissingSessionsWithDevices(XMPPConnection connection,
                                                                    OmemoDevice userDevice,
-                                                                   List<OmemoDevice> devices)
+                                                                   Set<OmemoDevice> devices)
             throws SmackException.NotConnectedException, InterruptedException, SmackException.NoResponseException {
-        ArrayList<OmemoDevice> devicesWithSession = new ArrayList<>();
+        Set<OmemoDevice> devicesWithSession = new HashSet<>();
         for (OmemoDevice device : devices) {
 
             if (hasSession(userDevice, device)) {
@@ -831,34 +834,34 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
 
     /**
      * Build OMEMO sessions with all devices of the contacts, we haven't had sessions with before.
-     * This method returns a list of OmemoDevices. This list contains all devices, with which we either had sessions
+     * This method returns a set of OmemoDevices. This set contains all devices, with which we either had sessions
      * before, plus those devices with which we just built sessions.
      *
      * @param connection authenticated XMPP connection.
      * @param userDevice our OmemoDevice
-     * @param contacts list of BareJids of contacts, we want to build sessions with.
-     * @return list of devices, we have sessions with.
+     * @param contacts set of BareJids of contacts, we want to build sessions with.
+     * @return set of devices, we have sessions with.
      * @throws SmackException.NotConnectedException
      * @throws InterruptedException
      * @throws SmackException.NoResponseException
      */
-    private ArrayList<OmemoDevice> buildMissingSessionsWithContacts(XMPPConnection connection,
+    private Set<OmemoDevice> buildMissingSessionsWithContacts(XMPPConnection connection,
                                                                     OmemoDevice userDevice,
-                                                                    List<BareJid> contacts)
+                                                                    Set<BareJid> contacts)
             throws SmackException.NotConnectedException, InterruptedException, SmackException.NoResponseException
     {
-        ArrayList<OmemoDevice> devicesWithSessions = new ArrayList<>();
+        Set<OmemoDevice> devicesWithSessions = new HashSet<>();
 
         for (BareJid contact : contacts) {
-            ArrayList<OmemoDevice> devices = buildMissingSessionsWithContact(connection, userDevice, contact);
+            Set<OmemoDevice> devices = buildMissingSessionsWithContact(connection, userDevice, contact);
             devicesWithSessions.addAll(devices);
         }
 
         return devicesWithSessions;
     }
 
-    private ArrayList<OmemoDevice> getUndecidedDevices(OmemoDevice userDevice, OmemoTrustCallback callback, List<OmemoDevice> devices) {
-        ArrayList<OmemoDevice> undecidedDevices = new ArrayList<>();
+    private Set<OmemoDevice> getUndecidedDevices(OmemoDevice userDevice, OmemoTrustCallback callback, Set<OmemoDevice> devices) {
+        Set<OmemoDevice> undecidedDevices = new HashSet<>();
 
         for (OmemoDevice device : devices) {
 
@@ -880,8 +883,8 @@ public abstract class OmemoService<T_IdKeyPair, T_IdKey, T_PreKey, T_SigPreKey,
         return undecidedDevices;
     }
 
-    private ArrayList<OmemoDevice> getUntrustedDeviced(OmemoDevice userDevice, OmemoTrustCallback trustCallback, List<OmemoDevice> devices) {
-        ArrayList<OmemoDevice> untrustedDevices = new ArrayList<>();
+    private Set<OmemoDevice> getUntrustedDeviced(OmemoDevice userDevice, OmemoTrustCallback trustCallback, Set<OmemoDevice> devices) {
+        Set<OmemoDevice> untrustedDevices = new HashSet<>();
 
         for (OmemoDevice device : devices) {