#2013 Enhance SUID extension message handling and correct encryption sync when the algorithm is detected as ACCORDION and the key ID and MI are both zero, indicating a bad algorithm ID value. (#2014)

Co-authored-by: Dennis Sheirer <dsheirer@github.com>

src/main/java/io/github/dsheirer/module/decode/p25/P25TrafficChannelManager.java

@@ -31,8 +31,10 @@ import io.github.dsheirer.identifier.IdentifierCollection;
 import io.github.dsheirer.identifier.MutableIdentifierCollection;
 import io.github.dsheirer.identifier.alias.TalkerAliasManager;
 import io.github.dsheirer.identifier.encryption.EncryptionKeyIdentifier;
+import io.github.dsheirer.identifier.patch.PatchGroupIdentifier;
 import io.github.dsheirer.identifier.patch.PatchGroupPreLoadDataContent;
 import io.github.dsheirer.identifier.scramble.ScrambleParameterIdentifier;
+import io.github.dsheirer.identifier.talkgroup.TalkgroupIdentifier;
 import io.github.dsheirer.log.LoggingSuppressor;
 import io.github.dsheirer.message.IMessage;
 import io.github.dsheirer.message.IMessageListener;
@@ -709,6 +711,78 @@ public class P25TrafficChannelManager extends TrafficChannelManager implements I
         }
     }
 
+    /**
+     * Process a Phase 1 HDU indicating a call start.
+     *
+     * @param frequency for the call event
+     * @param talkgroup to update within the event.
+     * @param eki for encryption settings.
+     * @param timestamp for the update
+     */
+    public void processP1TrafficCallStart(long frequency, Identifier<?> talkgroup, Identifier<?> radio,
+                                          EncryptionKeyIdentifier eki, ServiceOptions serviceOptions,
+                                          IChannelDescriptor channelDescriptor, long timestamp)
+    {
+        mLock.lock();
+
+        try
+        {
+            P25TrafficChannelEventTracker tracker = getTracker(frequency, P25P1Message.TIMESLOT_1);
+
+            if(tracker != null)
+            {
+                removeTracker(frequency, P25P1Message.TIMESLOT_1);
+            }
+
+            DecodeEventType decodeEventType = getDecodeEventType(talkgroup, eki);
+
+            MutableIdentifierCollection mic = new MutableIdentifierCollection();
+            mic.update(talkgroup);
+            mic.update(radio);
+            mic.update(eki);
+
+            //Create a new event for the current call.
+            P25ChannelGrantEvent callEvent = P25ChannelGrantEvent.builder(decodeEventType, timestamp, serviceOptions)
+                    .channelDescriptor(channelDescriptor)
+                    .details("PHASE 1 CALL " + (serviceOptions != null ? serviceOptions : ""))
+                    .identifiers(mic)
+                    .build();
+
+            tracker = new P25TrafficChannelEventTracker(callEvent);
+            addTracker(tracker, frequency, P25P1Message.TIMESLOT_1);
+            broadcast(tracker);
+        }
+        finally
+        {
+            mLock.unlock();
+        }
+    }
+
+    /**
+     * Determines the HDU message call decode event type from the talkgroup identifier and encryption key
+     * @param talkgroup to inspect
+     * @param eki to inspect
+     * @return decode event type.
+     */
+    private static DecodeEventType getDecodeEventType(Identifier talkgroup, EncryptionKeyIdentifier eki)
+    {
+        DecodeEventType decodeEventType = null;
+
+        if(talkgroup instanceof PatchGroupIdentifier)
+        {
+            decodeEventType = eki.isEncrypted() ? DecodeEventType.CALL_PATCH_GROUP_ENCRYPTED : DecodeEventType.CALL_PATCH_GROUP;
+        }
+        else if(talkgroup instanceof TalkgroupIdentifier ti && ti.getValue() == 0) //Unit-to-Unit private call
+        {
+            decodeEventType = eki.isEncrypted() ? DecodeEventType.CALL_UNIT_TO_UNIT_ENCRYPTED : DecodeEventType.CALL_UNIT_TO_UNIT;
+        }
+        else
+        {
+            decodeEventType = eki.isEncrypted() ? DecodeEventType.CALL_GROUP_ENCRYPTED : DecodeEventType.CALL_GROUP;
+        }
+        return decodeEventType;
+    }
+
     /**
      * Updates an identifier for an ongoing call event on the frequency and updates the event duration timestamp.
      *
@@ -755,6 +829,55 @@ public class P25TrafficChannelManager extends TrafficChannelManager implements I
         }
     }
 
+    /**
+     * Updates all current identifiers for an ongoing call event on the frequency and updates the event duration timestamp.
+     *
+     * Note: if this manager does not have an existing call event for the frequency, the update is ignored
+     * because we don't have enough detail to create a call event.
+     *
+     * This is used primarily to add encryption, GPS, talker alias, etc. but can be used for any identifier update.
+     *
+     * @param frequency for the call event
+     * @param identifier to update within the event.
+     * @param timestamp for the update
+     */
+    public void processP1TrafficCurrentUserIdentifiers(long frequency, List<Identifier> identifiers, long timestamp, String context)
+    {
+        mLock.lock();
+
+        try
+        {
+            P25TrafficChannelEventTracker tracker = getTracker(frequency, P25P1Message.TIMESLOT_1);
+
+            if(tracker != null && tracker.isComplete())
+            {
+                removeTracker(frequency, P25P1Message.TIMESLOT_1);
+                tracker = null;
+            }
+
+            if(tracker != null)
+            {
+                for(Identifier identifier : identifiers)
+                {
+                    tracker.addIdentifierIfMissing(identifier);
+
+                    //Add the encryption key to the call event details.
+                    if(identifier instanceof EncryptionKeyIdentifier eki && eki.isEncrypted())
+                    {
+                        tracker.addDetailsIfMissing(eki.toString());
+                    }
+                }
+
+                tracker.updateDurationTraffic(timestamp);
+                broadcast(tracker);
+            }
+        }
+        finally
+        {
+            mLock.unlock();
+        }
+    }
+
     /**
      * Processes traffic channel announced current user information.
      * @param frequency of the traffic channel

src/main/java/io/github/dsheirer/module/decode/p25/audio/P25P1CallSequenceRecorder.java

@@ -39,7 +39,7 @@ import io.github.dsheirer.module.decode.p25.phase1.message.ldu.EncryptionSyncPar
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU1Message;
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU2Message;
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDUMessage;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDUMessage;
 import io.github.dsheirer.preference.UserPreferences;
 import java.util.List;
@@ -119,9 +119,9 @@ public class P25P1CallSequenceRecorder extends MBECallSequenceRecorder
         {
             process((LDUMessage)message);
         }
-        else if(message instanceof TDULinkControlMessage)
+        else if(message instanceof TDULCMessage)
         {
-            process((TDULinkControlMessage)message);
+            process((TDULCMessage)message);
         }
         else if(message instanceof TDUMessage)
         {
@@ -133,7 +133,7 @@ public class P25P1CallSequenceRecorder extends MBECallSequenceRecorder
         }
     }
 
-    private void process(TDULinkControlMessage tdulc)
+    private void process(TDULCMessage tdulc)
     {
         process(tdulc.getLinkControlWord());
     }

src/main/java/io/github/dsheirer/module/decode/p25/phase1/P25P1DecoderState.java

@@ -61,7 +61,6 @@ import io.github.dsheirer.module.decode.p25.phase1.message.IFrequencyBand;
 import io.github.dsheirer.module.decode.p25.phase1.message.P25P1Message;
 import io.github.dsheirer.module.decode.p25.phase1.message.hdu.HDUMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.hdu.HeaderData;
-import io.github.dsheirer.module.decode.p25.phase1.message.lc.IExtendedSourceMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.LinkControlWord;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.l3harris.LCHarrisReturnToControlChannel;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.l3harris.LCHarrisTalkerAliasComplete;
@@ -113,7 +112,7 @@ import io.github.dsheirer.module.decode.p25.phase1.message.pdu.packet.PacketMess
 import io.github.dsheirer.module.decode.p25.phase1.message.pdu.packet.sndcp.SNDCPPacketMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.pdu.response.ResponseMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.pdu.umbtc.isp.UMBTCTelephoneInterconnectRequestExplicitDialing;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.tsbk.Opcode;
 import io.github.dsheirer.module.decode.p25.phase1.message.tsbk.TSBKMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.tsbk.harris.osp.L3HarrisGroupRegroupExplicitEncryptionCommand;
@@ -190,6 +189,7 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
     private final P25P1NetworkConfigurationMonitor mNetworkConfigurationMonitor;
     private final Listener<ChannelEvent> mChannelEventListener;
     private P25TrafficChannelManager mTrafficChannelManager;
+    private ServiceOptions mCurrentServiceOptions;
 
     /**
      * Constructs an APCO-25 decoder state with an optional traffic channel manager.
@@ -316,10 +316,6 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
                     break;
             }
         }
-        else if(iMessage instanceof IExtendedSourceMessage esm && iMessage instanceof LinkControlWord lcw)
-        {
-            processLC(lcw, esm.getTimestamp(), esm.isTerminator());
-        }
         else if(iMessage instanceof MotorolaTalkerAliasComplete tac)
         {
             mTrafficChannelManager.getTalkerAliasManager().update(tac.getRadio(), tac.getAlias());
@@ -413,7 +409,6 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
         getIdentifierCollection().update(updated);
         DecodeEventType decodeEventType = getLCDecodeEventType(lcw);
 
-
         ServiceOptions serviceOptions = null;
 
         if(lcw instanceof IServiceOptionsProvider sop)
@@ -831,17 +826,31 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
         if(message.isValid() && message instanceof HDUMessage hdu)
         {
             HeaderData headerData = hdu.getHeaderData();
-            //Run the talkgroup through the patch group manager so we don't get a plain talkgroup in addition to the patch
-            Identifier talkgroup = mPatchGroupManager.update(headerData.getTalkgroup(), message.getTimestamp());
-            mTrafficChannelManager.processP1TrafficCurrentUser(getCurrentFrequency(), talkgroup, hdu.getTimestamp(), message.toString());
 
-            if(headerData.isEncryptedAudio())
+            if(headerData.isValid())
             {
-                broadcast(new DecoderStateEvent(this, Event.START, State.ENCRYPTED));
-            }
-            else
-            {
-                broadcast(new DecoderStateEvent(this, Event.START, State.CALL));
+                Identifier talkgroup = headerData.getTalkgroup();
+
+                //Run the talkgroup through the patch group manager so we don't get a plain talkgroup in addition to the patch
+                //Talkgroup value of zero indicates a unit-to-unit call, so don't attempt to update it as a patch group
+                if(headerData.getTalkgroup().getValue() > 0)
+                {
+                    talkgroup = mPatchGroupManager.update(talkgroup, message.getTimestamp());
+                }
+
+                Identifier<?> radio = getIdentifierCollection().getFromIdentifier();
+
+                mTrafficChannelManager.processP1TrafficCallStart(getCurrentFrequency(), talkgroup, radio,
+                        headerData.getEncryptionKey(), mCurrentServiceOptions, getCurrentChannel(), message.getTimestamp());
+
+                if(headerData.isEncryptedAudio())
+                {
+                    broadcast(new DecoderStateEvent(this, Event.START, State.ENCRYPTED));
+                }
+                else
+                {
+                    broadcast(new DecoderStateEvent(this, Event.START, State.CALL));
+                }
             }
         }
     }
@@ -862,6 +871,8 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
             if(lcw != null && lcw.isValid())
             {
                 processLC(lcw, message.getTimestamp(), false);
+                mTrafficChannelManager.processP1TrafficCurrentUserIdentifiers(getCurrentFrequency(),
+                        getIdentifierCollection().getIdentifiers(), message.getTimestamp(), ldu1.toString());
             }
         }
         else if(message instanceof LDU2Message ldu2)
@@ -917,7 +928,7 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
             getIdentifierCollection().remove(IdentifierClass.USER, Role.FROM);
         }
 
-        if(message instanceof TDULinkControlMessage tdulc)
+        if(message instanceof TDULCMessage tdulc)
         {
             LinkControlWord lcw = tdulc.getLinkControlWord();
 
@@ -1831,7 +1842,10 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
     {
         switch(lcw.getOpcode())
         {
-            //Calls in-progress on this channel
+            case SOURCE_ID_EXTENSION:
+                //Ignore - handled elsewhere
+                break;
+            //Calls getting ready to start or in-progress on this channel
             case GROUP_VOICE_CHANNEL_USER:
             case MOTOROLA_GROUP_REGROUP_VOICE_CHANNEL_USER:
             case TELEPHONE_INTERCONNECT_VOICE_CHANNEL_USER:
@@ -1839,7 +1853,9 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
             case UNIT_TO_UNIT_VOICE_CHANNEL_USER_EXTENDED:
                 if(isTerminator)
                 {
-                    closeCurrentCallEvent(timestamp, lcw.toString());
+                    mTrafficChannelManager.processP1TrafficCallEnd(getCurrentFrequency(), timestamp, lcw.toString());
+                    List<Identifier> updated = mPatchGroupManager.update(lcw.getIdentifiers(), timestamp);
+                    getIdentifierCollection().update(updated);
                 }
                 else
                 {
@@ -1941,11 +1957,6 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
                     getIdentifierCollection().update(frequencyID);
                 }
 
-                if(isTerminator)
-                {
-                    closeCurrentCallEvent(timestamp, lcw.toString());
-                }
-
                 mNetworkConfigurationMonitor.process(lcw);
                 break;
             case NETWORK_STATUS_BROADCAST_EXPLICIT:
@@ -2162,9 +2173,6 @@ public class P25P1DecoderState extends DecoderState implements IChannelEventList
                     closeCurrentCallEvent(timestamp, lcw.toString());
                 }
                 break;
-            case SOURCE_ID_EXTENSION:
-                //Ignore - handled elsewhere
-                break;
             default:
                 if(isTerminator)
                 {

src/main/java/io/github/dsheirer/module/decode/p25/phase1/P25P1MessageProcessor.java

@@ -19,10 +19,12 @@
 package io.github.dsheirer.module.decode.p25.phase1;
 
 import io.github.dsheirer.channel.IChannelDescriptor;
+import io.github.dsheirer.message.AbstractMessage;
 import io.github.dsheirer.message.IMessage;
 import io.github.dsheirer.module.decode.p25.P25FrequencyBandPreloadDataContent;
 import io.github.dsheirer.module.decode.p25.phase1.message.IFrequencyBand;
 import io.github.dsheirer.module.decode.p25.phase1.message.IFrequencyBandReceiver;
+import io.github.dsheirer.module.decode.p25.phase1.message.hdu.HDUMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.IExtendedSourceMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.LinkControlWord;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.l3harris.HarrisTalkerAliasAssembler;
@@ -30,7 +32,8 @@ import io.github.dsheirer.module.decode.p25.phase1.message.lc.l3harris.LCHarrisT
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.motorola.LCMotorolaTalkerAliasAssembler;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.standard.LCSourceIDExtension;
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU1Message;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU2Message;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import io.github.dsheirer.sample.Listener;
 import java.util.List;
 import java.util.Map;
@@ -59,9 +62,12 @@ public class P25P1MessageProcessor implements Listener<IMessage>
     private Map<Integer,IFrequencyBand> mFrequencyBandMap = new TreeMap<Integer,IFrequencyBand>();
 
     /**
-     * Temporary holding of an extended source link control message while it awaits the extension message to arrive.
+     * Temporary holding for an extended source link control message while it awaits the extension message to arrive.
      */
-    private IExtendedSourceMessage mExtendedSourceMessage;
+    private TDULCMessage mHeldTDULCMessage;
+    private HDUMessage mHeldHDUMessage;
+    private LDU1Message mHeldLDU1Message;
+    private LDU2Message mHeldLDU2Message;
 
     /**
      * Motorola talker alias assembler for link control header and data blocks.
@@ -103,120 +109,200 @@ public class P25P1MessageProcessor implements Listener<IMessage>
     @Override
     public void receive(IMessage message)
     {
-        //Optional message created during processing that should be sent after the current argument is sent.
-        IMessage additionalMessageToSend = null;
-
         if(message.isValid())
         {
             //Reassemble extended source link control messages.
-            if(message instanceof LDU1Message ldu)
+            if(message instanceof LDU1Message ldu1)
             {
-                if(ldu.getLinkControlWord() instanceof IExtendedSourceMessage extendedSourceMessage)
+                LinkControlWord lcw = ldu1.getLinkControlWord();;
+
+                if(lcw instanceof IExtendedSourceMessage esm)
                 {
-                    additionalMessageToSend = reassembleLC(extendedSourceMessage);
+                    if(lcw instanceof LCSourceIDExtension extension)
+                    {
+                        processSourceIDExtension(extension);
+                    }
+                    else if(esm.isExtensionRequired())
+                    {
+                        processSourceIDExtension(null);
+                        mHeldLDU1Message = ldu1;
+                        return;
+                    }
                 }
-                else if(ldu.getLinkControlWord() instanceof LCHarrisTalkerAliasBase harrisTalkerAlias)
+                else if(lcw instanceof LCHarrisTalkerAliasBase harrisTalkerAlias)
                 {
                     //Send the LCW to the harris talker alias assembler
-                    additionalMessageToSend = mHarrisTalkerAliasAssembler.process(harrisTalkerAlias, ldu.getTimestamp());
+                    dispatch(mHarrisTalkerAliasAssembler.process(harrisTalkerAlias, ldu1.getTimestamp()));
+                }
+
+                //Flush any held messages
+                processSourceIDExtension(null);
+
+                dispatch(ldu1);
+            }
+            else if(message instanceof LDU2Message ldu2)
+            {
+                //If we held onto an LDU1 awaiting a source ID extension, then also hold onto this LDU2 and flush them in sequence.
+                if(mHeldLDU1Message != null)
+                {
+                    mHeldLDU2Message = ldu2;
+                }
+                else
+                {
+                    dispatch(ldu2);
                 }
             }
-            else if(message instanceof TDULinkControlMessage tdu)
+            else if(message instanceof TDULCMessage tdulc)
             {
-                LinkControlWord lcw = tdu.getLinkControlWord();
+                LinkControlWord lcw = tdulc.getLinkControlWord();
 
-                if(lcw instanceof IExtendedSourceMessage extendedSourceMessage)
+                if(lcw instanceof IExtendedSourceMessage esm)
                 {
-                    additionalMessageToSend = reassembleLC(extendedSourceMessage);
+                    if(lcw instanceof LCSourceIDExtension sourceIDExtension)
+                    {
+                        processSourceIDExtension(sourceIDExtension);
+                    }
+                    else if(esm.isExtensionRequired())
+                    {
+                        processSourceIDExtension(null);
+                        mHeldTDULCMessage = tdulc;
+                        return;
+                    }
                 }
+
                 //Motorola carries the talker alias in the TDULC
                 else if(mMotorolaTalkerAliasAssembler.add(lcw, message.getTimestamp()))
                 {
-                    additionalMessageToSend = mMotorolaTalkerAliasAssembler.assemble();
+                    dispatch(mMotorolaTalkerAliasAssembler.assemble());
                 }
 
-                //Harris carries the talker alias in the LDU voice messages, so reset the assembler on TDULC.
+                //Harris carries the talker alias in the LDU1 link control messages, so reset the assembler on TDULC.
                 mHarrisTalkerAliasAssembler.reset();
+
+                dispatch(tdulc);
             }
-
-            //Insert frequency band identifier update messages into channel-type messages */
-            if(message instanceof IFrequencyBandReceiver)
+            else if(message instanceof HDUMessage hdu && mHeldTDULCMessage != null)
             {
-                IFrequencyBandReceiver receiver = (IFrequencyBandReceiver)message;
-
-                List<IChannelDescriptor> channels = receiver.getChannels();
-
-                for(IChannelDescriptor channel : channels)
-                {
-                    int[] frequencyBandIdentifiers = channel.getFrequencyBandIdentifiers();
-
-                    for(int id : frequencyBandIdentifiers)
-                    {
-                        if(mFrequencyBandMap.containsKey(id))
-                        {
-                            channel.setFrequencyBand(mFrequencyBandMap.get(id));
-                        }
-                    }
-                }
+                //If the last TDULC message was held because it needs an extension that can arrive in the first LDU1,
+                //hold onto the intermediate HDU message and send everything (TDU, HDU, LDU) in correct sequence.
+                mHeldHDUMessage = hdu;
             }
-
-            //Store band identifiers so that they can be injected into channel type messages
-            if(message instanceof IFrequencyBand)
+            else
             {
-                IFrequencyBand bandIdentifier = (IFrequencyBand)message;
-
-                //Only store the frequency band if it's new so we don't hold on to more than one instance of the
-                //frequency band message.  Otherwise, we'll hold on to several instances of each message as they get
-                //injected into other messages with channel information.
-                if(!mFrequencyBandMap.containsKey(bandIdentifier.getIdentifier()))
-                {
-                    mFrequencyBandMap.put(bandIdentifier.getIdentifier(), bandIdentifier);
-                }
-            }
-        }
-
-        if(mMessageListener != null)
-        {
-            if(message != null)
-            {
-                mMessageListener.receive(message);
-            }
-
-            if(additionalMessageToSend != null)
-            {
-                mMessageListener.receive(additionalMessageToSend);
+                //flush any held messages
+                processSourceIDExtension(null);
+                dispatch(message);
             }
         }
     }
 
     /**
-     * Processes link control words to reassemble source ID extension messages.
-     * @param lcw to process
-     * @return reassembled link control or null if the original lcw is a receiver (which we hold onto and send later)
+     * Processes the source extension message and attaches it to any held TDULC or LDU1 with LC messages and flushes any
+     * held messages.
+     * @param extension to attach to held message(s) or null extension to flush all held messages.
      */
-    private IMessage reassembleLC(IExtendedSourceMessage lcw)
+    private void processSourceIDExtension(LCSourceIDExtension extension)
     {
-        IMessage toReturn = null;
-
-        if(lcw instanceof IExtendedSourceMessage extendedSourceMessage && extendedSourceMessage.isExtensionRequired())
+        if(mHeldTDULCMessage != null && mHeldTDULCMessage.getLinkControlWord() instanceof IExtendedSourceMessage esm)
         {
-            mExtendedSourceMessage = extendedSourceMessage;
-        }
-        else if(lcw instanceof LCSourceIDExtension sie && mExtendedSourceMessage != null)
-        {
-            mExtendedSourceMessage.setSourceIDExtension(sie);
-            toReturn = mExtendedSourceMessage;
-            mExtendedSourceMessage = null;
-        }
-        else
-        {
-            //The source extension message should always immediately follow the message that is being extended, so if
-            //we get a message that is not an extended message or the extension, then we've missed the extension and we
-            //should nullify any extended message that's waiting for the extension.
-            mExtendedSourceMessage = null;
+            esm.setSourceIDExtension(extension);
+            dispatch(mHeldTDULCMessage);
+            mHeldTDULCMessage = null;
+            dispatch(mHeldHDUMessage);
+            mHeldHDUMessage = null;
         }
 
-        return toReturn;
+        if(mHeldLDU1Message != null && mHeldLDU1Message.getLinkControlWord() instanceof IExtendedSourceMessage esm)
+        {
+            esm.setSourceIDExtension(extension);
+            dispatch(mHeldLDU1Message);
+            mHeldLDU1Message = null;
+            dispatch(mHeldLDU2Message);
+            mHeldLDU2Message = null;
+        }
+    }
+
+    /**
+     * Post-process the message for frequency band details.
+     * @param message to post process and dispatch
+     */
+    private void dispatch(IMessage message)
+    {
+        if(message == null)
+        {
+            return;
+        }
+
+        processForFrequencyBands(message);
+
+        //Also process the link control messages for frequency bands.
+        if(message instanceof LDU1Message ldu1)
+        {
+            processForFrequencyBands(ldu1.getLinkControlWord());
+        }
+        else if(message instanceof TDULCMessage tdulc)
+        {
+            processForFrequencyBands(tdulc.getLinkControlWord());
+        }
+
+        if(mMessageListener != null)
+        {
+            mMessageListener.receive(message);
+        }
+    }
+
+    /**
+     * Captures IDEN_UPDATE messages and attaches them to messages with channel descriptors.
+     * @param message to process for frequency band assembly.
+     */
+    private void processForFrequencyBands(IMessage message)
+    {
+        if(message instanceof AbstractMessage am)
+        {
+            processForFrequencyBands(am);
+        }
+    }
+
+    /**
+     * Captures IDEN_UPDATE messages and attaches them to messages with channel descriptors.
+     * @param message to process for frequency band assembly.
+     */
+    private void processForFrequencyBands(AbstractMessage message)
+    {
+        //Insert frequency band identifier update messages into channel-type messages */
+        if(message instanceof IFrequencyBandReceiver)
+        {
+            IFrequencyBandReceiver receiver = (IFrequencyBandReceiver)message;
+
+            List<IChannelDescriptor> channels = receiver.getChannels();
+
+            for(IChannelDescriptor channel : channels)
+            {
+                int[] frequencyBandIdentifiers = channel.getFrequencyBandIdentifiers();
+
+                for(int id : frequencyBandIdentifiers)
+                {
+                    if(mFrequencyBandMap.containsKey(id))
+                    {
+                        channel.setFrequencyBand(mFrequencyBandMap.get(id));
+                    }
+                }
+            }
+        }
+
+        //Store band identifiers so that they can be injected into channel type messages
+        if(message instanceof IFrequencyBand)
+        {
+            IFrequencyBand bandIdentifier = (IFrequencyBand)message;
+
+            //Only store the frequency band if it's new so we don't hold on to more than one instance of the
+            //frequency band message.  Otherwise, we'll hold on to several instances of each message as they get
+            //injected into other messages with channel information.
+            if(!mFrequencyBandMap.containsKey(bandIdentifier.getIdentifier()))
+            {
+                mFrequencyBandMap.put(bandIdentifier.getIdentifier(), bandIdentifier);
+            }
+        }
     }
 
     /**

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/P25MessageFactory.java

@@ -23,7 +23,7 @@ import io.github.dsheirer.module.decode.p25.phase1.P25P1DataUnitID;
 import io.github.dsheirer.module.decode.p25.phase1.message.hdu.HDUMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU1Message;
 import io.github.dsheirer.module.decode.p25.phase1.message.ldu.LDU2Message;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDUMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.vselp.VSELP1Message;
 import io.github.dsheirer.module.decode.p25.phase1.message.vselp.VSELP2Message;
@@ -65,7 +65,7 @@ public class P25MessageFactory
             case TERMINATOR_DATA_UNIT:
                 return new TDUMessage(message, nac, timestamp);
             case TERMINATOR_DATA_UNIT_LINK_CONTROL:
-                return new TDULinkControlMessage(message, nac, timestamp);
+                return new TDULCMessage(message, nac, timestamp);
             case TRUNKING_SIGNALING_BLOCK_1:
             case TRUNKING_SIGNALING_BLOCK_2:
             case TRUNKING_SIGNALING_BLOCK_3:

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/filter/TerminatorMessageFilter.java

@@ -1,6 +1,6 @@
 /*
  * *****************************************************************************
- * Copyright (C) 2014-2023 Dennis Sheirer
+ * Copyright (C) 2014-2024 Dennis Sheirer
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -23,7 +23,7 @@ import io.github.dsheirer.filter.Filter;
 import io.github.dsheirer.filter.FilterElement;
 import io.github.dsheirer.message.IMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.LinkControlOpcode;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import java.util.Collection;
 import java.util.function.Function;
 
@@ -63,7 +63,7 @@ public class TerminatorMessageFilter extends Filter<IMessage, LinkControlOpcode>
         @Override
         public LinkControlOpcode apply(IMessage message)
         {
-            if(message instanceof TDULinkControlMessage tdulc)
+            if(message instanceof TDULCMessage tdulc)
             {
                 return tdulc.getLinkControlWord().getOpcode();
             }

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/filter/TerminatorMessageFilterSet.java

@@ -1,6 +1,6 @@
 /*
  * *****************************************************************************
- * Copyright (C) 2014-2023 Dennis Sheirer
+ * Copyright (C) 2014-2024 Dennis Sheirer
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -22,7 +22,7 @@ package io.github.dsheirer.module.decode.p25.phase1.message.filter;
 import io.github.dsheirer.filter.FilterSet;
 import io.github.dsheirer.message.IMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.lc.LinkControlOpcode;
-import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULinkControlMessage;
+import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDULCMessage;
 import io.github.dsheirer.module.decode.p25.phase1.message.tdu.TDUMessage;
 import java.util.ArrayList;
 import java.util.List;
@@ -59,6 +59,6 @@ public class TerminatorMessageFilterSet extends FilterSet<IMessage>
     @Override
     public boolean canProcess(IMessage message)
     {
-        return (message instanceof TDUMessage || message instanceof TDULinkControlMessage) && super.canProcess(message);
+        return (message instanceof TDUMessage || message instanceof TDULCMessage) && super.canProcess(message);
     }
 }

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/hdu/HeaderData.java

@@ -1,23 +1,20 @@
 /*
+ * *****************************************************************************
+ * Copyright (C) 2014-2024 Dennis Sheirer
  *
- *  * ******************************************************************************
- *  * Copyright (C) 2014-2019 Dennis Sheirer
- *  *
- *  * This program is free software: you can redistribute it and/or modify
- *  * it under the terms of the GNU General Public License as published by
- *  * the Free Software Foundation, either version 3 of the License, or
- *  * (at your option) any later version.
- *  *
- *  * This program is distributed in the hope that it will be useful,
- *  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  * GNU General Public License for more details.
- *  *
- *  * You should have received a copy of the GNU General Public License
- *  * along with this program.  If not, see <http://www.gnu.org/licenses/>
- *  * *****************************************************************************
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
  *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * ****************************************************************************
  */
 
 package io.github.dsheirer.module.decode.p25.phase1.message.hdu;
@@ -25,11 +22,11 @@ package io.github.dsheirer.module.decode.p25.phase1.message.hdu;
 import io.github.dsheirer.bits.BinaryMessage;
 import io.github.dsheirer.identifier.Identifier;
 import io.github.dsheirer.identifier.encryption.EncryptionKeyIdentifier;
+import io.github.dsheirer.identifier.talkgroup.TalkgroupIdentifier;
 import io.github.dsheirer.module.decode.p25.identifier.encryption.APCO25EncryptionKey;
 import io.github.dsheirer.module.decode.p25.identifier.talkgroup.APCO25Talkgroup;
 import io.github.dsheirer.module.decode.p25.reference.Encryption;
 import io.github.dsheirer.module.decode.p25.reference.Vendor;
-
 import java.util.ArrayList;
 import java.util.List;
 
@@ -49,8 +46,8 @@ public class HeaderData
 
     private boolean mValid = true;
     private BinaryMessage mMessage;
-    private Identifier mEncryptionKey;
-    private Identifier mTalkgroup;
+    private EncryptionKeyIdentifier mEncryptionKey;
+    private TalkgroupIdentifier mTalkgroup;
     private List<Identifier> mIdentifiers;
 
     public HeaderData(BinaryMessage message)
@@ -129,9 +126,9 @@ public class HeaderData
         return Vendor.fromValue(getMessage().getInt(VENDOR_ID));
     }
 
-    public Identifier getEncryptionKey()
+    public EncryptionKeyIdentifier getEncryptionKey()
     {
-        if(mEncryptionKey == null && isEncryptedAudio())
+        if(mEncryptionKey == null)
         {
             mEncryptionKey = EncryptionKeyIdentifier.create(APCO25EncryptionKey.create(getMessage().getInt(ALGORITHM_ID),
                 getMessage().getInt(KEY_ID)));
@@ -150,7 +147,7 @@ public class HeaderData
         return getEncryption() != Encryption.UNENCRYPTED;
     }
 
-    public Identifier getTalkgroup()
+    public TalkgroupIdentifier getTalkgroup()
     {
         if(mTalkgroup == null)
         {

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/lc/standard/LCCallTermination.java

@@ -32,7 +32,8 @@ import java.util.List;
  */
 public class LCCallTermination extends LinkControlWord
 {
-    private static final int MOTOROLA_SYSTEM_CONTROLLER = 0xFFFFFD;
+    private static final int MOTOROLA_SYSTEM_CONTROLLER_1 = 0xFFFFFD;
+    private static final int MOTOROLA_SYSTEM_CONTROLLER_2 = 0xFFFFFF;
     private static final int HARRIS_SYSTEM_CONTROLLER = 0;
     private static final IntField ADDRESS = IntField.length24(OCTET_6_BIT_48);
     private Identifier mAddress;
@@ -75,7 +76,7 @@ public class LCCallTermination extends LinkControlWord
     public boolean isNetworkCommandedTeardown()
     {
         int address = getInt(ADDRESS);
-        return address == MOTOROLA_SYSTEM_CONTROLLER || address == HARRIS_SYSTEM_CONTROLLER;
+        return address == MOTOROLA_SYSTEM_CONTROLLER_1 || address == MOTOROLA_SYSTEM_CONTROLLER_2 || address == HARRIS_SYSTEM_CONTROLLER;
     }
 
     /**

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/ldu/EncryptionSyncParameters.java

@@ -1,23 +1,20 @@
 /*
+ * *****************************************************************************
+ * Copyright (C) 2014-2024 Dennis Sheirer
  *
- *  * ******************************************************************************
- *  * Copyright (C) 2014-2019 Dennis Sheirer
- *  *
- *  * This program is free software: you can redistribute it and/or modify
- *  * it under the terms of the GNU General Public License as published by
- *  * the Free Software Foundation, either version 3 of the License, or
- *  * (at your option) any later version.
- *  *
- *  * This program is distributed in the hope that it will be useful,
- *  * but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  * GNU General Public License for more details.
- *  *
- *  * You should have received a copy of the GNU General Public License
- *  * along with this program.  If not, see <http://www.gnu.org/licenses/>
- *  * *****************************************************************************
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
  *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
  *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>
+ * ****************************************************************************
  */
 
 package io.github.dsheirer.module.decode.p25.phase1.message.ldu;
@@ -27,7 +24,7 @@ import io.github.dsheirer.bits.BinaryMessage;
 import io.github.dsheirer.identifier.Identifier;
 import io.github.dsheirer.identifier.encryption.EncryptionKeyIdentifier;
 import io.github.dsheirer.module.decode.p25.identifier.encryption.APCO25EncryptionKey;
-
+import io.github.dsheirer.module.decode.p25.reference.Encryption;
 import java.util.ArrayList;
 import java.util.List;
 
@@ -36,6 +33,7 @@ import java.util.List;
  */
 public class EncryptionSyncParameters implements IEncryptionSyncParameters
 {
+    private static final String EMPTY_MESSAGE_INDICATOR = "000000000000000000";
     private static final int[] MESSAGE_INDICATOR_1 = {0, 1, 2, 3, 4, 5, 6, 7};
     private static final int[] MESSAGE_INDICATOR_2 = {8, 9, 10, 11, 12, 13, 14, 15};
     private static final int[] MESSAGE_INDICATOR_3 = {16, 17, 18, 19, 20, 21, 22, 23};
@@ -134,8 +132,16 @@ public class EncryptionSyncParameters implements IEncryptionSyncParameters
     {
         if(mEncryptionKey == null)
         {
-            mEncryptionKey = EncryptionKeyIdentifier.create(APCO25EncryptionKey.create(getMessage().getInt(ALGORITHM_ID),
-                getMessage().getInt(KEY_ID)));
+            int algorithm = getMessage().getInt(ALGORITHM_ID);
+            int key = getMessage().getInt(KEY_ID);
+
+            //Detect when algorithm, key and MI are all zeros and override algorithm to set as unencrypted.
+            if(algorithm == 0 && key == 0 && getMessageIndicator().contains(EMPTY_MESSAGE_INDICATOR))
+            {
+                algorithm = Encryption.UNENCRYPTED.getValue(); //0x80
+            }
+
+            mEncryptionKey = EncryptionKeyIdentifier.create(APCO25EncryptionKey.create(algorithm, key));
         }
 
         return mEncryptionKey;

src/main/java/io/github/dsheirer/module/decode/p25/phase1/message/tdu/TDULCMessage.java

@@ -31,7 +31,7 @@ import io.github.dsheirer.module.decode.p25.phase1.message.lc.LinkControlWordFac
 import java.util.Collections;
 import java.util.List;
 
-public class TDULinkControlMessage extends P25P1Message implements IFrequencyBandReceiver
+public class TDULCMessage extends P25P1Message implements IFrequencyBandReceiver
 {
     public static final int[] LC_HEX_0 = {0, 1, 2, 3, 4, 5};
     public static final int[] LC_HEX_1 = {6, 7, 8, 9, 10, 11};
@@ -63,7 +63,7 @@ public class TDULinkControlMessage extends P25P1Message implements IFrequencyBan
 
     private LinkControlWord mLinkControlWord;
 
-    public TDULinkControlMessage(CorrectedBinaryMessage message, int nac, long timestamp)
+    public TDULCMessage(CorrectedBinaryMessage message, int nac, long timestamp)
     {
         super(message, nac, timestamp);
     }