Code/Projects/PacketLevelSignatureExtractor/src/main/java/edu/uci/iotproject/SignatureGenerator.java

   1 package edu.uci.iotproject;
   2
   3 import static edu.uci.iotproject.analysis.UserAction.Type;
   4
   5 import edu.uci.iotproject.analysis.*;
   6 import edu.uci.iotproject.io.PrintWriterUtils;
   7 import edu.uci.iotproject.io.TriggerTimesFileReader;
   8 import edu.uci.iotproject.trafficreassembly.layer3.Conversation;
   9 import edu.uci.iotproject.trafficreassembly.layer3.TcpReassembler;
  10 import edu.uci.iotproject.util.PcapPacketUtils;
  11 import edu.uci.iotproject.util.PrintUtils;
  12 import org.apache.commons.math3.stat.clustering.Cluster;
  13 import org.apache.commons.math3.stat.clustering.DBSCANClusterer;
  14 import org.pcap4j.core.*;
  15 import org.pcap4j.packet.namednumber.DataLinkType;
  16
  17 import java.io.*;
  18 import java.net.UnknownHostException;
  19 import java.time.Duration;
  20 import java.time.Instant;
  21 import java.util.*;
  22 import java.util.concurrent.TimeoutException;
  23 import java.util.stream.Collectors;
  24 import java.util.stream.Stream;
  25
  26 /**
  27  * This is a system that reads PCAP files to compare
  28  * patterns of DNS hostnames, packet sequences, and packet
  29  * lengths with training data to determine certain events
  30  * or actions for smart home devices.
  31  *
  32  * @author Janus Varmarken
  33  * @author Rahmadi Trimananda (rtrimana@uci.edu)
  34  * @version 0.1
  35  */
  36 public class SignatureGenerator {
  37
  38     /**
  39      * If set to {@code true}, output written to the results file is also dumped to standard out.
  40      */
  41     private static boolean DUPLICATE_OUTPUT_TO_STD_OUT = true;
  42     /**
  43      * File name for logging.
  44      */
  45     private static String LOG_EXTENSION = "_signature-generation.log";
  46     /**
  47      * Directory for logging.
  48      */
  49     private static String LOG_DIRECTORY = "./";
  50     /**
  51      * Multiplier for cluster bounds.
  52      */
  53     private static float CLUSTER_BOUNDS_MULTIPLIER = 0.1f;
  54
  55     public static void main(String[] args) throws PcapNativeException, NotOpenException, EOFException,
  56             TimeoutException, UnknownHostException, IOException {
  57         // -------------------------------------------------------------------------------------------------------------
  58         // ------------ # Code for extracting traffic generated by a device within x seconds of a trigger # ------------
  59         if (args.length < 11) {
  60             String errMsg = String.format("SPECTO version 1.0\n" +
  61                             "Copyright (C) 2018-2019 Janus Varmarken and Rahmadi Trimananda.\n" +
  62                             "University of California, Irvine.\n" +
  63                             "All rights reserved.\n\n" +
  64                             "Usage: %s inputPcapFile outputPcapFile triggerTimesFile deviceIp" +
  65                             " onSignatureFile offSignatureFile onClusterAnalysisFile offClusterAnalysisFile epsilon" +
  66                             " deletedSequencesOn deletedSequencesOff" +
  67                             "\n  inputPcapFile: the target of the detection" +
  68                             "\n  outputPcapFile: the processed PCAP file through 15-second window filtering" +
  69                             "\n  triggerTimesFile: the trigger timestamps" +
  70                             "\n  deviceIp: the IP address of the device we want to generate a signature for" +
  71                             "\n  onSignatureFile: name of the ON signature file" +
  72                             "\n  offSignatureFile: name of the OFF signature file" +
  73                             "\n  onClusterAnalysisFile: name of the ON signature cluster analysis file" +
  74                             "\n  offClusterAnalysisFile: name of the OFF signature cluster analysis file" +
  75                             "\n  epsilon: epsilon value of the DBSCAN algorithm" +
  76                             "\n  deletedSequencesOn: sequences to be deleted from the final ON signature" +
  77                             " (please separate with commas, e.g., 0,1,2, or put '-1' if not needed)" +
  78                             "\n  deletedSequencesOff: sequences to be deleted from the final OFF signature" +
  79                             " (please separate with commas, e.g., 0,1,2, or put '-1' if not needed)",
  80                     SignatureGenerator.class.getSimpleName());
  81             System.out.println(errMsg);
  82             return;
  83         }
  84         boolean verbose = true;
  85         final String inputPcapFile = args[0];
  86         final String outputPcapFile = args[1];
  87         final String triggerTimesFile = args[2];
  88         final String deviceIp = args[3];
  89         final String onSignatureFile = args[4];
  90         final String offSignatureFile = args[5];
  91         final String onClusterAnalysisFile = args[6];
  92         final String offClusterAnalysisFile = args[7];
  93         final double eps = Double.parseDouble(args[8]);
  94         final String deletedSequencesOn = args[9];
  95         final String deletedSequencesOff = args[10];
  96         final String logFile = inputPcapFile + LOG_EXTENSION;
  97
  98         // Prepare file outputter.
  99         File outputFile = new File(logFile);
 100         outputFile.getParentFile().mkdirs();
 101         final PrintWriter resultsWriter = new PrintWriter(new FileWriter(outputFile));
 102
 103         // =========================================== TRAFFIC FILTERING ============================================
 104
 105         TriggerTimesFileReader ttfr = new TriggerTimesFileReader();
 106         List<Instant> triggerTimes = ttfr.readTriggerTimes(triggerTimesFile, false);
 107         // Tag each trigger with "ON" or "OFF", assuming that the first trigger is an "ON" and that they alternate.
 108         List<UserAction> userActions = new ArrayList<>();
 109         for (int i = 0; i < triggerTimes.size(); i++) {
 110             userActions.add(new UserAction(i % 2 == 0 ? Type.TOGGLE_ON : Type.TOGGLE_OFF, triggerTimes.get(i)));
 111         }
 112         TriggerTrafficExtractor tte = new TriggerTrafficExtractor(inputPcapFile, triggerTimes, deviceIp);
 113         final PcapDumper outputter = Pcaps.openDead(DataLinkType.EN10MB, 65536).dumpOpen(outputPcapFile);
 114         DnsMap dnsMap = new DnsMap();
 115         TcpReassembler tcpReassembler = new TcpReassembler();
 116         TrafficLabeler trafficLabeler = new TrafficLabeler(userActions);
 117         tte.performExtraction(pkt -> {
 118             try {
 119                 outputter.dump(pkt);
 120             } catch (NotOpenException e) {
 121                 e.printStackTrace();
 122             }
 123         }, dnsMap, tcpReassembler, trafficLabeler);
 124         outputter.flush();
 125         outputter.close();
 126
 127         if (tte.getPacketsIncludedCount() != trafficLabeler.getTotalPacketCount()) {
 128             // Sanity/debug check
 129             throw new AssertionError(String.format("mismatch between packet count in %s and %s",
 130                     TriggerTrafficExtractor.class.getSimpleName(), TrafficLabeler.class.getSimpleName()));
 131         }
 132
 133         // Extract all conversations present in the filtered trace.
 134         List<Conversation> allConversations = tcpReassembler.getTcpConversations();
 135         // Group conversations by hostname.
 136         Map<String, List<Conversation>> convsByHostname =
 137                 TcpConversationUtils.groupConversationsByHostname(allConversations, dnsMap);
 138         PrintWriterUtils.println("Grouped conversations by hostname.", resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 139         // For each hostname, count the frequencies of packet lengths exchanged with that hostname.
 140         final Map<String, Map<Integer, Integer>> pktLenFreqsByHostname = new HashMap<>();
 141         convsByHostname.forEach((host, convs) -> pktLenFreqsByHostname.put(host,
 142                 TcpConversationUtils.countPacketLengthFrequencies(convs)));
 143         PrintWriterUtils.println("Counted frequencies of packet lengths exchanged with each hostname.",
 144                 resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 145         // For each hostname, count the frequencies of packet sequences (i.e., count how many
 146         // conversations exchange a sequence of packets of some specific lengths).
 147         final Map<String, Map<String, Integer>> pktSeqFreqsByHostname = new HashMap<>();
 148         convsByHostname.forEach((host, convs) -> pktSeqFreqsByHostname.put(host,
 149                 TcpConversationUtils.countPacketSequenceFrequencies(convs)));
 150         PrintWriterUtils.println("Counted frequencies of packet sequences exchanged with each hostname.",
 151                 resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 152         // For each hostname, count frequencies of packet pairs exchanged
 153         // with that hostname across all conversations
 154         final Map<String, Map<String, Integer>> pktPairFreqsByHostname =
 155                 TcpConversationUtils.countPacketPairFrequenciesByHostname(allConversations, dnsMap);
 156         PrintWriterUtils.println("Counted frequencies of packet pairs per hostname.",
 157                 resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 158         // For each user action, reassemble the set of TCP connections occurring shortly after
 159         final Map<UserAction, List<Conversation>> userActionToConversations =
 160                 trafficLabeler.getLabeledReassembledTcpTraffic();
 161         final Map<UserAction, Map<String, List<Conversation>>> userActionsToConvsByHostname =
 162                 trafficLabeler.getLabeledReassembledTcpTraffic(dnsMap);
 163         PrintWriterUtils.println("Reassembled TCP conversations occurring shortly after each user event.",
 164                 resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 165
 166         /*
 167          * NOTE: no need to generate these more complex on/off maps that also contain mappings from hostname and
 168          * sequence identifiers as we do not care about hostnames and sequences during clustering.
 169          * We can simply use the UserAction->List<Conversation> map to generate ON/OFF groupings of conversations.
 170          */
 171         // Contains all ON events: hostname -> sequence identifier -> list of conversations with that sequence
 172         Map<String, Map<String, List<Conversation>>> ons = new HashMap<>();
 173         // Contains all OFF events: hostname -> sequence identifier -> list of conversations with that sequence
 174         Map<String, Map<String, List<Conversation>>> offs = new HashMap<>();
 175         userActionsToConvsByHostname.forEach((ua, hostnameToConvs) -> {
 176             Map<String, Map<String, List<Conversation>>> outer = ua.getType() == Type.TOGGLE_ON ? ons : offs;
 177             hostnameToConvs.forEach((host, convs) -> {
 178                 Map<String, List<Conversation>> seqsToConvs = TcpConversationUtils.
 179                         groupConversationsByPacketSequence(convs, verbose);
 180                 outer.merge(host, seqsToConvs, (oldMap, newMap) -> {
 181                     newMap.forEach((sequence, cs) -> oldMap.merge(sequence, cs, (list1, list2) -> {
 182                         list1.addAll(list2);
 183                         return list1;
 184                     }));
 185                     return oldMap;
 186                 });
 187             });
 188         });
 189
 190         // ============================================== PAIR CLUSTERING ============================================
 191         // TODO: No need to use the more convoluted on/off maps; Can simply use the UserAction->List<Conversation> map
 192         // TODO: when don't care about hostnames and sequences (see comment earlier).
 193         // ===========================================================================================================
 194         List<Conversation> onConversations = userActionToConversations.entrySet().stream().
 195                 filter(e -> e.getKey().getType() == Type.TOGGLE_ON). // drop all OFF events from stream
 196                 map(e -> e.getValue()). // no longer interested in the UserActions
 197                 flatMap(List::stream). // flatten List<List<T>> to a List<T>
 198                 collect(Collectors.toList());
 199         List<Conversation> offConversations = userActionToConversations.entrySet().stream().
 200                 filter(e -> e.getKey().getType() == Type.TOGGLE_OFF).
 201                 map(e -> e.getValue()).
 202                 flatMap(List::stream).
 203                 collect(Collectors.toList());
 204         //Collections.sort(onConversations, (c1, c2) -> c1.getPackets().)
 205
 206         List<PcapPacketPair> onPairs = onConversations.stream().
 207                 map(c -> c.isTls() ? TcpConversationUtils.extractTlsAppDataPacketPairs(c) :
 208                         TcpConversationUtils.extractPacketPairs(c)).
 209                 flatMap(List::stream). // flatten List<List<>> to List<>
 210                 collect(Collectors.toList());
 211         List<PcapPacketPair> offPairs = offConversations.stream().
 212                 map(c -> c.isTls() ? TcpConversationUtils.extractTlsAppDataPacketPairs(c) :
 213                         TcpConversationUtils.extractPacketPairs(c)).
 214                 flatMap(List::stream). // flatten List<List<>> to List<>
 215                 collect(Collectors.toList());
 216         // Note: need to update the DnsMap of all PcapPacketPairs if we want to use the IP/hostname-sensitive distance.
 217         Stream.concat(Stream.of(onPairs), Stream.of(offPairs)).flatMap(List::stream).forEach(p -> p.setDnsMap(dnsMap));
 218         // Perform clustering on conversation logged as part of all ON events.
 219         // Calculate number of events per type (only ON/only OFF), which means half of the number of all timestamps.
 220         int numberOfEventsPerType = triggerTimes.size() / 2;
 221         int lowerBound = numberOfEventsPerType - (int)(numberOfEventsPerType * CLUSTER_BOUNDS_MULTIPLIER);
 222         int upperBound = numberOfEventsPerType + (int)(numberOfEventsPerType * CLUSTER_BOUNDS_MULTIPLIER);
 223         int minPts = lowerBound;
 224         DBSCANClusterer<PcapPacketPair> onClusterer = new DBSCANClusterer<>(eps, minPts);
 225         List<Cluster<PcapPacketPair>> onClusters = onClusterer.cluster(onPairs);
 226         // Perform clustering on conversation logged as part of all OFF events.
 227         DBSCANClusterer<PcapPacketPair> offClusterer = new DBSCANClusterer<>(eps, minPts);
 228         List<Cluster<PcapPacketPair>> offClusters = offClusterer.cluster(offPairs);
 229         // Sort the conversations as reference
 230         List<Conversation> sortedAllConversation = TcpConversationUtils.sortConversationList(allConversations);
 231         // Output clusters
 232         PrintWriterUtils.println("========================================", resultsWriter,
 233                 DUPLICATE_OUTPUT_TO_STD_OUT);
 234         PrintWriterUtils.println("       Clustering results for ON        ", resultsWriter,
 235                 DUPLICATE_OUTPUT_TO_STD_OUT);
 236         PrintWriterUtils.println("       Number of clusters: " + onClusters.size(), resultsWriter,
 237                 DUPLICATE_OUTPUT_TO_STD_OUT);
 238         int count = 0;
 239         List<List<List<PcapPacket>>> ppListOfListReadOn = new ArrayList<>();
 240         List<List<List<PcapPacket>>> ppListOfListListOn = new ArrayList<>();
 241         List<List<List<PcapPacket>>> corePointRangeSignatureOn = new ArrayList<>();
 242         for (Cluster<PcapPacketPair> c : onClusters) {
 243             PrintWriterUtils.println(String.format("<<< Cluster #%02d (%03d points) >>>", ++count, c.getPoints().size()),
 244                     resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 245             PrintWriterUtils.println(PrintUtils.toSummaryString(c), resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 246             if(c.getPoints().size() > lowerBound && c.getPoints().size() < upperBound) {
 247                 // Print to file
 248                 List<List<PcapPacket>> ppListOfList = PcapPacketUtils.clusterToListOfPcapPackets(c);
 249                 // Check for overlaps and decide whether to do range-based or conservative checking
 250                 corePointRangeSignatureOn.add(PcapPacketUtils.extractRangeCorePoints(ppListOfList, eps, minPts));
 251                 ppListOfListListOn.add(ppListOfList);
 252             }
 253         }
 254         PrintWriterUtils.println("========================================", resultsWriter,
 255                 DUPLICATE_OUTPUT_TO_STD_OUT);
 256         PrintWriterUtils.println("       Clustering results for OFF        ", resultsWriter,
 257                 DUPLICATE_OUTPUT_TO_STD_OUT);
 258         PrintWriterUtils.println("       Number of clusters: " + offClusters.size(), resultsWriter,
 259                 DUPLICATE_OUTPUT_TO_STD_OUT);
 260         count = 0;
 261         List<List<List<PcapPacket>>> ppListOfListReadOff = new ArrayList<>();
 262         List<List<List<PcapPacket>>> ppListOfListListOff = new ArrayList<>();
 263         List<List<List<PcapPacket>>> corePointRangeSignatureOff = new ArrayList<>();
 264         for (Cluster<PcapPacketPair> c : offClusters) {
 265             PrintWriterUtils.println(String.format("<<< Cluster #%03d (%06d points) >>>", ++count, c.getPoints().size()),
 266                     resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 267             PrintWriterUtils.println(PrintUtils.toSummaryString(c), resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 268             if(c.getPoints().size() > lowerBound && c.getPoints().size() < upperBound) {
 269                 // Print to file
 270                 List<List<PcapPacket>> ppListOfList = PcapPacketUtils.clusterToListOfPcapPackets(c);
 271                 // Check for overlaps and decide whether to do range-based or conservative checking
 272                 corePointRangeSignatureOff.add(PcapPacketUtils.extractRangeCorePoints(ppListOfList, eps, minPts));
 273                 ppListOfListListOff.add(ppListOfList);
 274             }
 275         }
 276
 277         // =========================================== SIGNATURE CREATION ===========================================
 278         // Concatenate
 279         ppListOfListListOn = PcapPacketUtils.concatSequences(ppListOfListListOn, sortedAllConversation);
 280         // Remove sequences in the list that have overlap
 281         StringTokenizer stringTokenizerOn = new StringTokenizer(deletedSequencesOn, ",");
 282         while(stringTokenizerOn.hasMoreTokens()) {
 283             int sequenceToDelete = Integer.parseInt(stringTokenizerOn.nextToken());
 284             if (sequenceToDelete == -1) { // '-1' means there is no removal
 285                 break;
 286             }
 287             PcapPacketUtils.removeSequenceFromSignature(ppListOfListListOn, sequenceToDelete);
 288         }
 289         PrintWriterUtils.println("ON Sequences: ", resultsWriter,
 290                 DUPLICATE_OUTPUT_TO_STD_OUT);
 291         for(List<List<PcapPacket>> listOfList : ppListOfListListOn) {
 292             PrintWriterUtils.println(listOfList.get(0).get(0).length() + "...", resultsWriter,
 293                     DUPLICATE_OUTPUT_TO_STD_OUT);
 294         }
 295         ppListOfListListOn = PcapPacketUtils.sortSequences(ppListOfListListOn);
 296         PrintWriterUtils.println("Concatenated and sorted ON signature sequences...", resultsWriter,
 297                 DUPLICATE_OUTPUT_TO_STD_OUT);
 298
 299         // Concatenate
 300         ppListOfListListOff = PcapPacketUtils.concatSequences(ppListOfListListOff, sortedAllConversation);
 301         // Remove sequences in the list that have overlap
 302         StringTokenizer stringTokenizerOff = new StringTokenizer(deletedSequencesOff, ",");
 303         while(stringTokenizerOff.hasMoreTokens()) {
 304             int sequenceToDelete = Integer.parseInt(stringTokenizerOff.nextToken());
 305             if (sequenceToDelete == -1) { // '-1' means there is no removal
 306                 break;
 307             }
 308             PcapPacketUtils.removeSequenceFromSignature(ppListOfListListOff, sequenceToDelete);
 309         }
 310         PrintWriterUtils.println("OFF Sequences: ", resultsWriter,
 311                 DUPLICATE_OUTPUT_TO_STD_OUT);
 312         for(List<List<PcapPacket>> listOfList : ppListOfListListOff) {
 313             PrintWriterUtils.println(listOfList.get(0).get(0).length() + "...", resultsWriter,
 314                     DUPLICATE_OUTPUT_TO_STD_OUT);
 315         }
 316         ppListOfListListOff = PcapPacketUtils.sortSequences(ppListOfListListOff);
 317         PrintWriterUtils.println("Concatenated and sorted OFF signature sequences...", resultsWriter,
 318                 DUPLICATE_OUTPUT_TO_STD_OUT);
 319
 320         // Write the signatures into the screen
 321         PrintWriterUtils.println("========================================", resultsWriter,
 322                 DUPLICATE_OUTPUT_TO_STD_OUT);
 323         PrintWriterUtils.println("              ON Signature              ", resultsWriter,
 324                 DUPLICATE_OUTPUT_TO_STD_OUT);
 325         PrintWriterUtils.println("========================================", resultsWriter,
 326                 DUPLICATE_OUTPUT_TO_STD_OUT);
 327         PcapPacketUtils.printSignatures(ppListOfListListOn, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 328         PrintWriterUtils.println("========================================", resultsWriter,
 329                 DUPLICATE_OUTPUT_TO_STD_OUT);
 330         PrintWriterUtils.println("              OFF Signature             ", resultsWriter,
 331                 DUPLICATE_OUTPUT_TO_STD_OUT);
 332         PrintWriterUtils.println("========================================", resultsWriter,
 333                 DUPLICATE_OUTPUT_TO_STD_OUT);
 334         PcapPacketUtils.printSignatures(ppListOfListListOff, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 335         // Clean signatures from null elements
 336         PcapPacketUtils.cleanSignature(ppListOfListListOn);
 337         PcapPacketUtils.cleanSignature(ppListOfListListOff);
 338         // Printing signatures into files
 339         PrintUtils.serializeIntoFile(onSignatureFile, ppListOfListListOn);
 340         PrintUtils.serializeIntoFile(offSignatureFile, ppListOfListListOff);
 341         // Printing cluster analyses into files
 342         PrintUtils.serializeIntoFile(onClusterAnalysisFile, corePointRangeSignatureOn);
 343         PrintUtils.serializeIntoFile(offClusterAnalysisFile, corePointRangeSignatureOff);
 344
 345         // =========================================== SIGNATURE DURATIONS =============================================
 346         List<Instant> firstSignatureTimestamps = new ArrayList<>();
 347         List<Instant> lastSignatureTimestamps = new ArrayList<>();
 348         if (!ppListOfListListOn.isEmpty()) {
 349             List<List<PcapPacket>> firstListOnSign = ppListOfListListOn.get(0);
 350             List<List<PcapPacket>> lastListOnSign = ppListOfListListOn.get(ppListOfListListOn.size() - 1);
 351             // Load ON signature first and last packet's timestamps
 352             for (List<PcapPacket> list : firstListOnSign) {
 353                 // Get timestamp Instant from the last packet
 354                 firstSignatureTimestamps.add(list.get(0).getTimestamp());
 355             }
 356             for (List<PcapPacket> list : lastListOnSign) {
 357                 // Get timestamp Instant from the last packet
 358                 int lastPacketIndex = list.size() - 1;
 359                 lastSignatureTimestamps.add(list.get(lastPacketIndex).getTimestamp());
 360             }
 361         }
 362
 363         if (!ppListOfListListOff.isEmpty()) {
 364             List<List<PcapPacket>> firstListOffSign = ppListOfListListOff.get(0);
 365             List<List<PcapPacket>> lastListOffSign = ppListOfListListOff.get(ppListOfListListOff.size() - 1);
 366             // Load OFF signature first and last packet's timestamps
 367             for (List<PcapPacket> list : firstListOffSign) {
 368                 // Get timestamp Instant from the last packet
 369                 firstSignatureTimestamps.add(list.get(0).getTimestamp());
 370             }
 371             for (List<PcapPacket> list : lastListOffSign) {
 372                 // Get timestamp Instant from the last packet
 373                 int lastPacketIndex = list.size() - 1;
 374                 lastSignatureTimestamps.add(list.get(lastPacketIndex).getTimestamp());
 375             }
 376         }
 377         // Sort the timestamps
 378         firstSignatureTimestamps.sort(Comparator.comparing(Instant::toEpochMilli));
 379         lastSignatureTimestamps.sort(Comparator.comparing(Instant::toEpochMilli));
 380
 381         Iterator<Instant> iterFirst = firstSignatureTimestamps.iterator();
 382         Iterator<Instant> iterLast = lastSignatureTimestamps.iterator();
 383         long duration;
 384         long maxDuration = Long.MIN_VALUE;
 385         PrintWriterUtils.println("========================================", resultsWriter,
 386                 DUPLICATE_OUTPUT_TO_STD_OUT);
 387         PrintWriterUtils.println("           Signature Durations          ", resultsWriter,
 388                 DUPLICATE_OUTPUT_TO_STD_OUT);
 389         PrintWriterUtils.println("========================================", resultsWriter,
 390                 DUPLICATE_OUTPUT_TO_STD_OUT);
 391         while (iterFirst.hasNext() && iterLast.hasNext()) {
 392             Instant firstInst = iterFirst.next();
 393             Instant lastInst = iterLast.next();
 394             Duration dur = Duration.between(firstInst, lastInst);
 395             duration = dur.toMillis();
 396             // Check duration --- should be below 15 seconds
 397             if (duration > TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS) {
 398                 while (duration > TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS && iterFirst.hasNext()) {
 399                     // that means we have to move to the next trigger
 400                     firstInst = iterFirst.next();
 401                     dur = Duration.between(firstInst, lastInst);
 402                     duration = dur.toMillis();
 403                 }
 404             } else { // Below 0/Negative --- that means we have to move to the next signature
 405                 while (duration < 0 && iterLast.hasNext()) {
 406                     // that means we have to move to the next trigger
 407                     lastInst = iterLast.next();
 408                     dur = Duration.between(firstInst, lastInst);
 409                     duration = dur.toMillis();
 410                 }
 411             }
 412             PrintWriterUtils.println(duration, resultsWriter, DUPLICATE_OUTPUT_TO_STD_OUT);
 413             // Update duration if this bigger than the max value and still less than the window inclusion time
 414             maxDuration = maxDuration < duration && duration <= TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS ?
 415                     duration : maxDuration;
 416         }
 417         // Just assign the value 0 if there is no signature
 418         if (maxDuration == Long.MIN_VALUE) {
 419             maxDuration = 0;
 420         }
 421         PrintWriterUtils.println("========================================", resultsWriter,
 422                 DUPLICATE_OUTPUT_TO_STD_OUT);
 423         PrintWriterUtils.println("Max signature duration: " + maxDuration, resultsWriter,
 424                 DUPLICATE_OUTPUT_TO_STD_OUT);
 425         PrintWriterUtils.println("========================================", resultsWriter,
 426                 DUPLICATE_OUTPUT_TO_STD_OUT);
 427         resultsWriter.flush();
 428         resultsWriter.close();
 429         // ==========================================================================================================
 430     }
 431 }