--- /dev/null
+package edu.uci.iotproject.detection;
+
+import edu.uci.iotproject.Conversation;
+import edu.uci.iotproject.TcpReassembler;
+import edu.uci.iotproject.analysis.TcpConversationUtils;
+import edu.uci.iotproject.io.PcapHandleReader;
+import edu.uci.iotproject.util.PrintUtils;
+import org.pcap4j.core.*;
+
+import java.time.ZoneId;
+import java.util.*;
+import java.util.stream.Collectors;
+
+import static edu.uci.iotproject.util.PcapPacketUtils.*;
+
+/**
+ * Searches a traffic trace for sequences of packets "belong to" a given cluster (in other words, attempts to classify
+ * traffic as pertaining to a given cluster).
+ *
+ * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
+ * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
+ */
+public class ClusterMatcher implements PacketListener {
+
+ // Test client
+ public static void main(String[] args) throws PcapNativeException, NotOpenException {
+
+// String path = "/scratch/July-2018"; // Rahmadi
+ String path = "/Users/varmarken/temp/UCI IoT Project/experiments"; // Janus
+ final String inputPcapFile = path + "/2018-07/dlink/dlink.wlan1.local.pcap";
+ final String signatureFile = path + "/2018-07/dlink/offSignature1.sig";
+
+ List<List<PcapPacket>> signature = PrintUtils.deserializeClustersFromFile(signatureFile);
+ ClusterMatcher clusterMatcher = new ClusterMatcher(signature, null,
+ (sig, match) -> System.out.println(
+ String.format("[ !!! SIGNATURE DETECTED AT %s !!! ]",
+ match.get(0).getTimestamp().atZone(ZoneId.of("America/Los_Angeles")))
+ )
+ );
+
+ PcapHandle handle;
+ try {
+ handle = Pcaps.openOffline(inputPcapFile, PcapHandle.TimestampPrecision.NANO);
+ } catch (PcapNativeException pne) {
+ handle = Pcaps.openOffline(inputPcapFile);
+ }
+ PcapHandleReader reader = new PcapHandleReader(handle, p -> true, clusterMatcher);
+ reader.readFromHandle();
+ clusterMatcher.performDetection();
+ }
+
+ /**
+ * The cluster that describes the sequence of packets that this {@link ClusterMatcher} is trying to detect in the
+ * observed traffic.
+ */
+ private final List<List<PcapPacket>> mCluster;
+
+ /**
+ * The ordered directions of packets in the sequences that make up {@link #mCluster}.
+ */
+ private final Conversation.Direction[] mClusterMemberDirections;
+
+ /**
+ * For reassembling the observed traffic into TCP connections.
+ */
+ private final TcpReassembler mTcpReassembler = new TcpReassembler();
+
+ /**
+ * IP of the router's WAN port (if analyzed traffic is captured at the ISP's point of view).
+ */
+ private final String mRouterWanIp;
+
+ private final ClusterMatchObserver[] mObservers;
+
+ /**
+ * Create a {@link ClusterMatcher}.
+ * @param cluster The cluster that traffic is matched against.
+ * @param routerWanIp The router's WAN IP if examining traffic captured at the ISP's point of view (used for
+ * determining the direction of packets).
+ * @param detectionObservers Client code that wants to get notified whenever the {@link ClusterMatcher} detects that
+ * (a subset of) the examined traffic is similar to the traffic that makes up
+ * {@code cluster}, i.e., when the examined traffic is classified as pertaining to
+ * {@code cluster}.
+ */
+ public ClusterMatcher(List<List<PcapPacket>> cluster, String routerWanIp, ClusterMatchObserver... detectionObservers) {
+ mCluster = Collections.unmodifiableList(Objects.requireNonNull(cluster, "cluster cannot be null"));
+ mObservers = Objects.requireNonNull(detectionObservers, "detectionObservers cannot be null");
+ if (mCluster.isEmpty() || mCluster.stream().anyMatch(inner -> inner.isEmpty())) {
+ throw new IllegalArgumentException("cluster is empty (or contains an empty inner List)");
+ }
+ if (mObservers.length == 0) {
+ throw new IllegalArgumentException("no detectionObservers provided");
+ }
+ mRouterWanIp = routerWanIp;
+ // Build the cluster members' direction sequence.
+ // Note: assumes that the provided cluster was captured within the local network (routerWanIp is set to null).
+ mClusterMemberDirections = getPacketDirections(mCluster.get(0), null);
+ /*
+ * Enforce restriction on cluster members: all representatives must exhibit the same direction pattern and
+ * contain the same number of packets. Note that this is a somewhat heavy operation, so it may be disabled later
+ * on in favor of performance. However, it is only run once (at instantiation), so the overhead may be warranted
+ * in order to ensure correctness, especially during the development/debugging phase.
+ */
+ if (mCluster.stream().
+ anyMatch(inner -> !Arrays.equals(mClusterMemberDirections, getPacketDirections(inner, null)))) {
+ throw new IllegalArgumentException(
+ "cluster members must contain the same number of packets and exhibit the same packet direction " +
+ "pattern"
+ );
+ }
+ }
+
+ @Override
+ public void gotPacket(PcapPacket packet) {
+ // Present packet to TCP reassembler so that it can be mapped to a connection (if it is a TCP packet).
+ mTcpReassembler.gotPacket(packet);
+ }
+
+ /**
+ * Get the cluster that describes the packet sequence that this {@link ClusterMatcher} is searching for.
+ * @return the cluster that describes the packet sequence that this {@link ClusterMatcher} is searching for.
+ */
+ public List<List<PcapPacket>> getCluster() {
+ return mCluster;
+ }
+
+ public void performDetection() {
+ /*
+ * Let's start out simple by building a version that only works for signatures that do not span across multiple
+ * TCP conversations...
+ */
+ for (Conversation c : mTcpReassembler.getTcpConversations()) {
+ if (c.isTls() && c.getTlsApplicationDataPackets().isEmpty() || !c.isTls() && c.getPackets().isEmpty()) {
+ // Skip empty conversations.
+ continue;
+ }
+ for (List<PcapPacket> signatureSequence : mCluster) {
+ if (isTlsSequence(signatureSequence) != c.isTls()) {
+ // We consider it a mismatch if one is a TLS application data sequence and the other is not.
+ continue;
+ }
+ // Fetch set of packets to examine based on TLS or not.
+ List<PcapPacket> cPkts = c.isTls() ? c.getTlsApplicationDataPackets() : c.getPackets();
+ /*
+ * Note: we embed the attempt to detect the signature sequence in a loop in order to capture those cases
+ * where the same signature sequence appears multiple times in one Conversation.
+ *
+ * Note: as the cluster can be made up of identical sequences, we must keep track of whether we detected
+ * a match and, if so, break the inner for-each loop in order to prevent raising an alarm for each
+ * cluster-member (prevent duplicate detections of the same event). However, a negative side-effect of
+ * this is that, in doing so, we will also skip searching for subsequent different cluster members in
+ * the current conversation if the current cluster member is a match.
+ *
+ * Note: since we expect all sequences that together make up the signature to exhibit the same direction
+ * pattern, we can simply pass the precomputed direction array for the signature sequence so that it
+ * won't have to be recomputed internally in each call to findSubsequenceInSequence().
+ */
+ Optional<List<PcapPacket>> match;
+ boolean matchFound = false;
+ while ((match = findSubsequenceInSequence(signatureSequence, cPkts, mClusterMemberDirections, null)).
+ isPresent()) {
+ matchFound = true;
+ List<PcapPacket> matchSeq = match.get();
+ // Notify observers about the match.
+ Arrays.stream(mObservers).forEach(o -> o.onMatch(ClusterMatcher.this, matchSeq));
+ /*
+ * Get the index in cPkts of the last packet in the sequence of packets that matches the searched
+ * signature sequence.
+ */
+ int matchSeqEndIdx = cPkts.indexOf(matchSeq.get(matchSeq.size()-1));
+ // We restart the search for the signature sequence immediately after that index, so truncate cPkts.
+ cPkts = cPkts.stream().skip(matchSeqEndIdx + 1).collect(Collectors.toList());
+ }
+ if (matchFound) {
+ // Break inner for-each loop in order to avoid duplicate detection of same event (see comment above)
+ break;
+ }
+ }
+ /*
+ * TODO:
+ * if no item in cluster matches, also perform a distance-based matching to cover those cases where we did
+ * not manage to capture every single mutation of the sequence during training.
+ *
+ * Need to compute average/centroid of cluster to do so...? Compute within-cluster variance, then check if
+ * distance between input conversation and cluster average/centroid is smaller than or equal to the computed
+ * variance?
+ */
+ }
+ }
+
+ /**
+ * Checks if {@code sequence} is a sequence of TLS packets. Note: the current implementation relies on inspection
+ * of the port numbers when deciding between TLS vs. non-TLS. Therefore, only the first packet of {@code sequence}
+ * is examined as it is assumed that all packets in {@code sequence} pertain to the same {@link Conversation} and
+ * hence share the same set of two src/dst port numbers (albeit possibly alternating between which one is the src
+ * and which one is the dst, as packets in {@code sequence} may be in alternating directions).
+ * @param sequence The sequence of packets for which it is to be determined if it is a sequence of TLS packets or
+ * non-TLS packets.
+ * @return {@code true} if {@code sequence} is a sequence of TLS packets, {@code false} otherwise.
+ */
+ private boolean isTlsSequence(List<PcapPacket> sequence) {
+ // NOTE: Assumes ALL packets in sequence pertain to the same TCP connection!
+ PcapPacket firstPkt = sequence.get(0);
+ int srcPort = getSourcePort(firstPkt);
+ int dstPort = getDestinationPort(firstPkt);
+ return TcpConversationUtils.isTlsPort(srcPort) || TcpConversationUtils.isTlsPort(dstPort);
+ }
+
+ /**
+ * Examine if a given sequence of packets ({@code sequence}) contains a given shorter sequence of packets
+ * ({@code subsequence}). Note: the current implementation actually searches for a substring as it does not allow
+ * for interleaving packets in {@code sequence} that are not in {@code subsequence}; for example, if
+ * {@code subsequence} consists of packet lengths [2, 3, 5] and {@code sequence} consists of packet lengths
+ * [2, 3, 4, 5], the result will be that there is no match (because of the interleaving 4). If we are to allow
+ * interleaving packets, we need a modified version of
+ * <a href="https://stackoverflow.com/a/20545604/1214974">this</a>.
+ *
+ * @param subsequence The sequence to search for.
+ * @param sequence The sequence to search.
+ * @param subsequenceDirections The directions of packets in {@code subsequence} such that for all {@code i},
+ * {@code subsequenceDirections[i]} is the direction of the packet returned by
+ * {@code subsequence.get(i)}. May be set to {@code null}, in which this call will
+ * internally compute the packet directions.
+ * @param sequenceDirections The directions of packets in {@code sequence} such that for all {@code i},
+ * {@code sequenceDirections[i]} is the direction of the packet returned by
+ * {@code sequence.get(i)}. May be set to {@code null}, in which this call will internally
+ * compute the packet directions.
+ *
+ * @return An {@link Optional} containing the part of {@code sequence} that matches {@code subsequence}, or an empty
+ * {@link Optional} if no part of {@code sequence} matches {@code subsequence}.
+ */
+ private Optional<List<PcapPacket>> findSubsequenceInSequence(List<PcapPacket> subsequence,
+ List<PcapPacket> sequence,
+ Conversation.Direction[] subsequenceDirections,
+ Conversation.Direction[] sequenceDirections) {
+ if (sequence.size() < subsequence.size()) {
+ // If subsequence is longer, it cannot be contained in sequence.
+ return Optional.empty();
+ }
+ if (isTlsSequence(subsequence) != isTlsSequence(sequence)) {
+ // We consider it a mismatch if one is a TLS application data sequence and the other is not.
+ return Optional.empty();
+ }
+ // If packet directions have not been precomputed by calling code, we need to construct them.
+ if (subsequenceDirections == null) {
+ subsequenceDirections = getPacketDirections(subsequence, mRouterWanIp);
+ }
+ if (sequenceDirections == null) {
+ sequenceDirections = getPacketDirections(sequence, mRouterWanIp);
+ }
+ int subseqIdx = 0;
+ int seqIdx = 0;
+ while (seqIdx < sequence.size()) {
+ PcapPacket subseqPkt = subsequence.get(subseqIdx);
+ PcapPacket seqPkt = sequence.get(seqIdx);
+ // We only have a match if packet lengths and directions match.
+ if (subseqPkt.getOriginalLength() == seqPkt.getOriginalLength() &&
+ subsequenceDirections[subseqIdx] == sequenceDirections[seqIdx]) {
+ // A match; advance both indices to consider next packet in subsequence vs. next packet in sequence.
+ subseqIdx++;
+ seqIdx++;
+ if (subseqIdx == subsequence.size()) {
+ // We managed to match the entire subsequence in sequence.
+ // Return the sublist of sequence that matches subsequence.
+ /*
+ * TODO:
+ * ASSUMES THE BACKING LIST (i.e., 'sequence') IS _NOT_ STRUCTURALLY MODIFIED, hence may not work
+ * for live traces!
+ */
+ return Optional.of(sequence.subList(seqIdx - subsequence.size(), seqIdx));
+ }
+ } else {
+ // Mismatch.
+ if (subseqIdx > 0) {
+ /*
+ * If we managed to match parts of subsequence, we restart the search for subsequence in sequence at
+ * the index of sequence where the current mismatch occurred. I.e., we must reset subseqIdx, but
+ * leave seqIdx untouched.
+ */
+ subseqIdx = 0;
+ } else {
+ /*
+ * First packet of subsequence didn't match packet at seqIdx of sequence, so we move forward in
+ * sequence, i.e., we continue the search for subsequence in sequence starting at index seqIdx+1 of
+ * sequence.
+ */
+ seqIdx++;
+ }
+ }
+ }
+ return Optional.empty();
+ }
+
+ /**
+ * Given a {@code List<PcapPacket>}, generate a {@code Conversation.Direction[]} such that each entry in the
+ * resulting {@code Conversation.Direction[]} specifies the direction of the {@link PcapPacket} at the corresponding
+ * index in the input list.
+ * @param packets The list of packets for which to construct a corresponding array of packet directions.
+ * @param routerWanIp The IP of the router's WAN port. This is used for determining the direction of packets when
+ * the traffic is captured just outside the local network (at the ISP side of the router). Set to
+ * {@code null} if {@code packets} stem from traffic captured within the local network.
+ * @return A {@code Conversation.Direction[]} specifying the direction of the {@link PcapPacket} at the
+ * corresponding index in {@code packets}.
+ */
+ private static Conversation.Direction[] getPacketDirections(List<PcapPacket> packets, String routerWanIp) {
+ Conversation.Direction[] directions = new Conversation.Direction[packets.size()];
+ for (int i = 0; i < packets.size(); i++) {
+ PcapPacket pkt = packets.get(i);
+ if (getSourceIp(pkt).equals(getDestinationIp(pkt))) {
+ // Sanity check: we shouldn't be processing loopback traffic
+ throw new AssertionError("loopback traffic detected");
+ }
+ if (isSrcIpLocal(pkt) || getSourceIp(pkt).equals(routerWanIp)) {
+ directions[i] = Conversation.Direction.CLIENT_TO_SERVER;
+ } else if (isDstIpLocal(pkt) || getDestinationIp(pkt).equals(routerWanIp)) {
+ directions[i] = Conversation.Direction.SERVER_TO_CLIENT;
+ } else {
+ throw new IllegalArgumentException("no local IP or router WAN port IP found, can't detect direction");
+ }
+ }
+ return directions;
+ }
+
+ /**
+ * Interface used by client code to register for receiving a notification whenever the {@link ClusterMatcher}
+ * detects traffic that is similar to the traffic that makes up the cluster returned by
+ * {@link ClusterMatcher#getCluster()}.
+ */
+ interface ClusterMatchObserver {
+ /**
+ * Callback that is invoked whenever a sequence that is similar to a sequence associated with the cluster (i.e.,
+ * a sequence is a member of the cluster) is detected in the traffic that the associated {@link ClusterMatcher}
+ * observes.
+ * @param clusterMatcher The {@link ClusterMatcher} that detected a match (classified traffic as pertaining to
+ * its associated cluster).
+ * @param match The traffic that was deemed to match the cluster associated with {@code clusterMatcher}.
+ */
+ void onMatch(ClusterMatcher clusterMatcher, List<PcapPacket> match);
+ }
+
+}
package edu.uci.iotproject.detection;
-import edu.uci.iotproject.Conversation;
-import edu.uci.iotproject.TcpReassembler;
-import edu.uci.iotproject.analysis.TcpConversationUtils;
+import edu.uci.iotproject.analysis.TriggerTrafficExtractor;
+import edu.uci.iotproject.analysis.UserAction;
import edu.uci.iotproject.io.PcapHandleReader;
import edu.uci.iotproject.util.PrintUtils;
+import org.jgrapht.GraphPath;
+import org.jgrapht.alg.shortestpath.DijkstraShortestPath;
+import org.jgrapht.graph.DefaultWeightedEdge;
+import org.jgrapht.graph.SimpleDirectedWeightedGraph;
import org.pcap4j.core.*;
+import java.time.Duration;
import java.time.ZoneId;
+import java.time.format.DateTimeFormatter;
+import java.time.format.FormatStyle;
import java.util.*;
-import java.util.stream.Collectors;
-
-import static edu.uci.iotproject.util.PcapPacketUtils.*;
+import java.util.function.Consumer;
/**
- * TODO add class documentation.
+ * Detects an event signature that spans one or multiple TCP connections.
*
* @author Janus Varmarken {@literal <jvarmark@uci.edu>}
* @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
*/
-public class SignatureDetector implements PacketListener {
+public class SignatureDetector implements PacketListener, ClusterMatcher.ClusterMatchObserver {
// Test client
public static void main(String[] args) throws PcapNativeException, NotOpenException {
-
-// String path = "/scratch/July-2018"; // Rahmadi
+ // String path = "/scratch/July-2018"; // Rahmadi
String path = "/Users/varmarken/temp/UCI IoT Project/experiments"; // Janus
+
+ // Kwikset Doorlock Sep 12 experiment
+ final String inputPcapFile = path + "/2018-08/kwikset-doorlock/kwikset3.wlan1.local.pcap";
+ // Kwikset Doorlock PHONE signatures
+ final String onSignatureFile = path + "/2018-08/kwikset-doorlock/onSignature-Kwikset-Doorlock-phone.sig";
+ final String offSignatureFile = path + "/2018-08/kwikset-doorlock/offSignature-Kwikset-Doorlock-phone.sig";
+
+ /*
+ // D-Link Plug experiment
final String inputPcapFile = path + "/2018-07/dlink/dlink.wlan1.local.pcap";
- final String signatureFile = path + "/2018-07/dlink/offSignature1.sig";
+ // D-Link Plug DEVICE signatures
+ final String onSignatureFile = path + "/2018-07/dlink/onSignature-DLink-Plug-device.sig";
+ final String offSignatureFile = path + "/2018-07/dlink/offSignature-DLink-Plug-device.sig";
+ // D-Link Plug PHONE signatures
+ final String onSignatureFile = path + "/2018-07/dlink/onSignature-DLink-Plug-phone.sig";
+ final String offSignatureFile = path + "/2018-07/dlink/offSignature-DLink-Plug-phone.sig";
+ */
+
+ /*
+ // D-Link Siren experiment
+ final String inputPcapFile = path + "/2018-08/dlink-siren/dlink-siren.wlan1.local.pcap";
+ // D-Link Siren DEVICE signatures
+ final String onSignatureFile = path + "/2018-08/dlink-siren/onSignature-DLink-Siren-device.sig";
+ final String offSignatureFile = path + "/2018-08/dlink-siren/offSignature-DLink-Siren-device.sig";
+ // D-Link Siren PHONE signatures
+ final String onSignatureFile = path + "/2018-08/dlink-siren/onSignature-DLink-Siren-phone.sig";
+ final String offSignatureFile = path + "/2018-08/dlink-siren/offSignature-DLink-Siren-phone.sig";
+ */
+
+ List<List<List<PcapPacket>>> onSignature = PrintUtils.deserializeSignatureFromFile(onSignatureFile);
+ List<List<List<PcapPacket>>> offSignature = PrintUtils.deserializeSignatureFromFile(offSignatureFile);
- List<List<PcapPacket>> signature = PrintUtils.deserializeClustersFromFile(signatureFile);
- SignatureDetector signatureDetector = new SignatureDetector(signature, null,
- (sig, match) -> System.out.println(
- String.format("[ !!! SIGNATURE DETECTED AT %s !!! ]",
- match.get(0).getTimestamp().atZone(ZoneId.of("America/Los_Angeles")))
- )
- );
+ SignatureDetector onDetector = new SignatureDetector(onSignature, null);
+ SignatureDetector offDetector = new SignatureDetector(offSignature, null);
+
+ final DateTimeFormatter dateTimeFormatter = DateTimeFormatter.ofLocalizedDateTime(FormatStyle.MEDIUM).
+ withLocale(Locale.US).withZone(ZoneId.of("America/Los_Angeles"));
+
+ // Outputs information about a detected event to std.out
+ final Consumer<UserAction> outputter = ua -> {
+ String eventDescription;
+ switch (ua.getType()) {
+ case TOGGLE_ON:
+ eventDescription = "ON";
+ break;
+ case TOGGLE_OFF:
+ eventDescription = "OFF";
+ break;
+ default:
+ throw new AssertionError("unhandled event type");
+ }
+ String output = String.format("[ !!! %s SIGNATURE DETECTED at %s !!! ]",
+ eventDescription, dateTimeFormatter.format(ua.getTimestamp()));
+ System.out.println(output);
+ };
+
+ // Let's create observers that construct a UserAction representing the detected event.
+ final List<UserAction> detectedEvents = new ArrayList<>();
+ onDetector.addObserver((searched, match) -> {
+ PcapPacket firstPkt = match.get(0).get(0);
+ detectedEvents.add(new UserAction(UserAction.Type.TOGGLE_ON, firstPkt.getTimestamp()));
+ });
+ offDetector.addObserver((searched, match) -> {
+ PcapPacket firstPkt = match.get(0).get(0);
+ detectedEvents.add(new UserAction(UserAction.Type.TOGGLE_OFF, firstPkt.getTimestamp()));
+ });
PcapHandle handle;
try {
} catch (PcapNativeException pne) {
handle = Pcaps.openOffline(inputPcapFile);
}
- PcapHandleReader reader = new PcapHandleReader(handle, p -> true, signatureDetector);
+ PcapHandleReader reader = new PcapHandleReader(handle, p -> true, onDetector, offDetector);
reader.readFromHandle();
- signatureDetector.performDetection();
+
+ // TODO: need a better way of triggering detection than this...
+ onDetector.mClusterMatchers.forEach(cm -> cm.performDetection());
+ offDetector.mClusterMatchers.forEach(cm -> cm.performDetection());
+
+ // Sort the list of detected events by timestamp to make it easier to compare it line-by-line with the trigger
+ // times file.
+ Collections.sort(detectedEvents, Comparator.comparing(UserAction::getTimestamp));
+ // Output the detected events
+ detectedEvents.forEach(outputter);
}
/**
- * The signature that this {@link SignatureDetector} is trying to detect in the observed traffic.
+ * The signature that this {@link SignatureDetector} is searching for.
*/
- private final List<List<PcapPacket>> mSignature;
+ private final List<List<List<PcapPacket>>> mSignature;
/**
- * The directions of packets in the sequences that make up {@link #mSignature}.
+ * The {@link ClusterMatcher}s in charge of detecting each individual sequence of packets that together make up the
+ * the signature.
*/
- private final Conversation.Direction[] mSignatureDirections;
+ private final List<ClusterMatcher> mClusterMatchers;
/**
- * For reassembling the observed traffic into TCP connections.
+ * For each {@code i} ({@code i >= 0 && i < pendingMatches.length}), {@code pendingMatches[i]} holds the matches
+ * found by the {@link ClusterMatcher} at {@code mClusterMatchers.get(i)} that have yet to be "consumed", i.e.,
+ * have yet to be included in a signature detected by this {@link SignatureDetector} (a signature can be encompassed
+ * of multiple packet sequences occurring shortly after one another on multiple connections).
*/
- private final TcpReassembler mTcpReassembler = new TcpReassembler();
+ private final List<List<PcapPacket>>[] pendingMatches;
/**
- * IP of the router's WAN port (if analyzed traffic is captured at the ISP's point of view).
+ * Maps a {@link ClusterMatcher} to its corresponding index in {@link #pendingMatches}.
*/
- private final String mRouterWanIp;
+ private final Map<ClusterMatcher, Integer> mClusterMatcherIds;
- private final Observer[] mObservers;
+ private final List<SignatureDetectionObserver> mObservers = new ArrayList<>();
- public SignatureDetector(List<List<PcapPacket>> signature, String routerWanIp, Observer... detectionObservers) {
- mSignature = Collections.unmodifiableList(Objects.requireNonNull(signature, "signature cannot be null"));
- mObservers = Objects.requireNonNull(detectionObservers, "detectionObservers cannot be null");
- if (mSignature.isEmpty() || mSignature.stream().anyMatch(inner -> inner.isEmpty())) {
- throw new IllegalArgumentException("signature is empty (or contains empty inner List)");
+ public SignatureDetector(List<List<List<PcapPacket>>> searchedSignature, String routerWanIp) {
+ // note: doesn't protect inner lists from changes :'(
+ mSignature = Collections.unmodifiableList(searchedSignature);
+ // Generate corresponding/appropriate ClusterMatchers based on the provided signature
+ List<ClusterMatcher> clusterMatchers = new ArrayList<>();
+ for (List<List<PcapPacket>> cluster : mSignature) {
+ clusterMatchers.add(new ClusterMatcher(cluster, routerWanIp, this));
}
- if (mObservers.length == 0) {
- throw new IllegalArgumentException("no detectionObservers provided");
+ mClusterMatchers = Collections.unmodifiableList(clusterMatchers);
+
+ // < exploratory >
+ pendingMatches = new List[mClusterMatchers.size()];
+ for (int i = 0; i < pendingMatches.length; i++) {
+ pendingMatches[i] = new ArrayList<>();
}
- mRouterWanIp = routerWanIp;
- // Build the signature's direction sequence.
- // Note: assumes that the provided signature was captured within the local network (routerWanIp is set to null).
- mSignatureDirections = getPacketDirections(mSignature.get(0), null);
- /*
- * Enforce restriction on cluster/signature members: all representatives must exhibit the same direction pattern
- * and contain the same number of packets. Note that this is a somewhat heavy operation, so it may be disabled
- * later on in favor of performance. However, it is only run once (at instantiation), so the overhead may be
- * warranted in order to ensure correctness, especially during the development/debugging phase.
- */
- if (mSignature.stream().
- anyMatch(inner -> !Arrays.equals(mSignatureDirections, getPacketDirections(inner, null)))) {
- throw new IllegalArgumentException(
- "signature members must contain the same number of packets and exhibit the same packet direction " +
- "pattern"
- );
+ Map<ClusterMatcher, Integer> clusterMatcherIds = new HashMap<>();
+ for (int i = 0; i < mClusterMatchers.size(); i++) {
+ clusterMatcherIds.put(mClusterMatchers.get(i), i);
}
+ mClusterMatcherIds = Collections.unmodifiableMap(clusterMatcherIds);
+ }
+
+ public void addObserver(SignatureDetectionObserver observer) {
+ mObservers.add(observer);
+ }
+
+ public boolean removeObserver(SignatureDetectionObserver observer) {
+ return mObservers.remove(observer);
}
@Override
public void gotPacket(PcapPacket packet) {
- // Present packet to TCP reassembler so that it can be mapped to a connection (if it is a TCP packet).
- mTcpReassembler.gotPacket(packet);
+ // simply delegate packet reception to all ClusterMatchers.
+ mClusterMatchers.forEach(cm -> cm.gotPacket(packet));
}
+ @Override
+ public void onMatch(ClusterMatcher clusterMatcher, List<PcapPacket> match) {
+ // Add the match at the corresponding index
+ pendingMatches[mClusterMatcherIds.get(clusterMatcher)].add(match);
+ checkSignatureMatch();
+ }
-// public void performDetection() {
-// // Let's start out simple by building a version that only works for signatures that do not span across multiple
-// // TCP conversations...
-// for (Conversation c : mTcpReassembler.getTcpConversations()) {
-// for (List<PcapPacket> sequence : mSignature) {
-// boolean matchFound = isSequenceInConversation(sequence, c);
-// if (matchFound) {
-// for (Observer obs : mObservers) {
-// obs.onSequenceDetected(sequence, c);
-// }
-// // Found signature in current conversation, so break inner loop and continue with next conversation.
-// // TODO: signature can be present more than once in Conversation...
-// break;
-// }
-// }
-// /*
-// * TODO:
-// * if no item in cluster matches, also perform a distance-based matching to cover those cases where we did
-// * not manage to capture every single mutation of the sequence during training.
-// *
-// * Need to compute average/centroid of cluster to do so...? Compute within-cluster variance, then check if
-// * distance between input conversation and cluster average/centroid is smaller than or equal to the computed
-// * variance?
-// */
-// }
-// }
-
+ private void checkSignatureMatch() {
+ // << Graph-based approach using Balint's idea. >>
+ // This implementation assumes that the packets in the inner lists (the sequences) are ordered by asc timestamp.
- public void performDetection() {
- /*
- * Let's start out simple by building a version that only works for signatures that do not span across multiple
- * TCP conversations...
- */
- for (Conversation c : mTcpReassembler.getTcpConversations()) {
- if (c.isTls() && c.getTlsApplicationDataPackets().isEmpty() || !c.isTls() && c.getPackets().isEmpty()) {
- // Skip empty conversations.
- continue;
- }
- for (List<PcapPacket> signatureSequence : mSignature) {
- if (isTlsSequence(signatureSequence) != c.isTls()) {
- // We consider it a mismatch if one is a TLS application data sequence and the other is not.
- continue;
+ // There cannot be a signature match until each ClusterMatcher has found a match of its respective sequence.
+ if (Arrays.stream(pendingMatches).noneMatch(l -> l.isEmpty())) {
+ // Construct the DAG
+ final SimpleDirectedWeightedGraph<Vertex, DefaultWeightedEdge> graph =
+ new SimpleDirectedWeightedGraph<>(DefaultWeightedEdge.class);
+ // Add a vertex for each match found by all ClusterMatchers
+ // And maintain an array to keep track of what cluster matcher each vertex corresponds to
+ final List<Vertex>[] vertices = new List[pendingMatches.length];
+ for (int i = 0; i < pendingMatches.length; i++) {
+ vertices[i] = new ArrayList<>();
+ for (List<PcapPacket> sequence : pendingMatches[i]) {
+ Vertex v = new Vertex(sequence);
+ vertices[i].add(v); // retain reference for later when we are to add edges
+ graph.addVertex(v); // add to vertex to graph
}
- // Fetch set of packets to examine based on TLS or not.
- List<PcapPacket> cPkts = c.isTls() ? c.getTlsApplicationDataPackets() : c.getPackets();
- /*
- * Note: we embed the attempt to detect the signature sequence in a loop in order to capture those cases
- * where the same signature sequence appears multiple times in one Conversation.
- *
- * Note: as the cluster can be made up of identical sequences, we must keep track of whether we detected
- * a match and, if so, break the inner for-each loop in order to prevent raising an alarm for each
- * cluster-member (prevent duplicate detections of the same event). However, a negative side-effect of
- * this is that, in doing so, we will also skip searching for subsequent different cluster members in
- * the current conversation if the current cluster member is a match.
- *
- * Note: since we expect all sequences that together make up the signature to exhibit the same direction
- * pattern, we can simply pass the precomputed direction array for the signature sequence so that it
- * won't have to be recomputed internally in each call to findSubsequenceInSequence().
- */
- Optional<List<PcapPacket>> match;
- boolean matchFound = false;
- while ((match = findSubsequenceInSequence(signatureSequence, cPkts, mSignatureDirections, null)).
- isPresent()) {
- matchFound = true;
- List<PcapPacket> matchSeq = match.get();
- // Notify observers about the match.
- Arrays.stream(mObservers).forEach(o -> o.onSignatureDetected(mSignature, matchSeq));
- /*
- * Get the index in cPkts of the last packet in the sequence of packets that matches the searched
- * signature sequence.
- */
- int matchSeqEndIdx = cPkts.indexOf(matchSeq.get(matchSeq.size()-1));
- // We restart the search for the signature sequence immediately after that index, so truncate cPkts.
- cPkts = cPkts.stream().skip(matchSeqEndIdx + 1).collect(Collectors.toList());
- }
- if (matchFound) {
- // Break inner for-each loop in order to avoid duplicate detection of same event (see comment above)
- break;
- }
-
-
-// match.ifPresent(ps -> Arrays.stream(mObservers).forEach(o -> o.onSignatureDetected(mSignature, ps)));
-// if (match.isPresent()) {
-// /*
-// * We found an element in the signature cluster that was present in conversation, so no need to scan
-// * conversation for remaining members of signature cluster (in fact, we'd be getting duplicate
-// * output in those cases where the cluster is made up of identical sequences if we did not stop the
-// * search here).
-// *
-// * TODO:
-// * How do we handle those cases where the conversation matches the signature more than once (for
-// * example, the long-lived connections used for sending the trigger from the cloud)?
-// */
-// break;
-// }
}
- }
- }
-
-// /**
-// * Examine if a {@link Conversation} contains a given sequence of packets. Note: the current implementation actually
-// * searches for a substring as it does not allow for interleaved packets in {@code c} that are not in
-// * {@code sequence}; for example, if {@code sequence} consists of packet lengths [2, 3, 5] and {@code c} consists of
-// * packet lengths [2, 3, 4, 5], the result will be {@code false}. If we are to allow interleaved packets, we need
-// * a modified version of <a href="https://stackoverflow.com/a/20545604/1214974">this</a>.
-// * @param sequence The sequence to look for.
-// * @param c The {@link Conversation} to search for {@code sequence} in.
-// * @return {@code true} if {@code c} contains {@code sequence}, {@code false} otherwise.
-// */
-// private boolean isSequenceInConversation(List<PcapPacket> sequence, Conversation c) {
-// // TODO add offset argument to allow looking for sequence starting later in Conversation.
-// // The packets we match against differ depending on whether the signature is a TLS or non-TLS signature.
-// boolean tlsSequence = isTlsSequence(sequence);
-// if (tlsSequence && !c.isTls()) {
-// // If we're looking for a TLS signature and this conversation does not appear to be a TLS conversation, we
-// // are done. Note: this assumes that they do NOT start performing TLS on new ports that are not captured in
-// // Conversation.isTls()
-// return false;
-// }
-// // Based on TLS or non-TLS signature, fetch the corresponding list of packets to match against.
-// List<PcapPacket> packets = tlsSequence ? c.getTlsApplicationDataPackets() : c.getPackets();
-// // If sequence is longer than the conversation, it can obviously not be contained in the conversation.
-// if (packets.size() < sequence.size()) {
-// return false;
-// }
-// /*
-// * Generate packet direction array for c. We have already generated the packet direction array for sequence as
-// * part of the constructor (mSignatureDirections).
-// */
-// Conversation.Direction[] cDirections = getPacketDirections(packets, mRouterWanIp);
-// int seqIdx = 0;
-// int convIdx = 0;
-// while (convIdx < packets.size()) {
-// PcapPacket seqPkt = sequence.get(seqIdx);
-// PcapPacket convPkt = packets.get(convIdx);
-// // We only have a match if packet lengths and directions match.
-// if (convPkt.getOriginalLength() == seqPkt.getOriginalLength() &&
-// mSignatureDirections[seqIdx] == cDirections[convIdx]) {
-// // A match, advance both indices to consider next packet in sequence vs. next packet in conversation
-// seqIdx++;
-// convIdx++;
-// if (seqIdx == sequence.size()) {
-// // we managed to match the full sequence in the conversation.
-// return true;
-// }
-// } else {
-// // Mismatch.
-// if (seqIdx > 0) {
-// /*
-// * If we managed to match parts of sequence, we restart the search for sequence in c at the index of
-// * c where the current mismatch occurred. I.e., we must reset seqIdx, but leave convIdx untouched.
-// */
-// seqIdx = 0;
-// } else {
-// /*
-// * First packet of sequence didn't match packet at convIdx of conversation, so we move forward in
-// * conversation, i.e., we continue the search for sequence in c starting at index convIdx+1 of c.
-// */
-// convIdx++;
-// }
-// }
-// }
-// return false;
-// }
-
- private boolean isTlsSequence(List<PcapPacket> sequence) {
- // NOTE: Assumes ALL packets in sequence pertain to the same TCP connection!
- PcapPacket firstPkt = sequence.get(0);
- int srcPort = getSourcePort(firstPkt);
- int dstPort = getDestinationPort(firstPkt);
- return TcpConversationUtils.isTlsPort(srcPort) || TcpConversationUtils.isTlsPort(dstPort);
- }
-
-// private List<PcapPacket> findeSequenceInConversation(List<PcapPacket> sequence, Conversation conv, int offset) {
-// if (isTlsSequence(sequence) != conv.isTls()) {
-// // We consider it a mismatch if one is a TLS Application Data sequence and the other is not.
-// return null;
-// }
-// List<PcapPacket> convPackets = conv.isTls() ? conv.getTlsApplicationDataPackets() : conv.getPackets();
+ // Add dummy source and sink vertices to facilitate search.
+ final Vertex source = new Vertex(null);
+ final Vertex sink = new Vertex(null);
+ graph.addVertex(source);
+ graph.addVertex(sink);
+ // The source is connected to all vertices that wrap the sequences detected by ClusterMatcher at index 0.
+ // Note: zero cost edges as this is just a dummy link to facilitate search from a common start node.
+ for (Vertex v : vertices[0]) {
+ DefaultWeightedEdge edge = graph.addEdge(source, v);
+ graph.setEdgeWeight(edge, 0.0);
+ }
+ // Similarly, all vertices that wrap the sequences detected by the last ClusterMatcher of the signature
+ // are connected to the sink node.
+ for (Vertex v : vertices[vertices.length-1]) {
+ DefaultWeightedEdge edge = graph.addEdge(v, sink);
+ graph.setEdgeWeight(edge, 0.0);
+ }
+ // Now link sequences detected by ClusterMatcher at index i to sequences detected by ClusterMatcher at index
+ // i+1 if they obey the timestamp constraint (i.e., that the latter is later in time than the former).
+ for (int i = 0; i < vertices.length; i++) {
+ int j = i + 1;
+ if (j < vertices.length) {
+ for (Vertex iv : vertices[i]) {
+ PcapPacket ivLast = iv.sequence.get(iv.sequence.size()-1);
+ for (Vertex jv : vertices[j]) {
+ PcapPacket jvFirst = jv.sequence.get(jv.sequence.size()-1);
+ if (ivLast.getTimestamp().isBefore(jvFirst.getTimestamp())) {
+ DefaultWeightedEdge edge = graph.addEdge(iv, jv);
+ // The weight is the duration of the i'th sequence plus the duration between the i'th
+ // and i+1'th sequence.
+ Duration d = Duration.
+ between(iv.sequence.get(0).getTimestamp(), jvFirst.getTimestamp());
+ // Unfortunately weights are double values, so must convert from long to double.
+ // TODO: need nano second precision? If so, use d.toNanos().
+ // TODO: risk of overflow when converting from long to double..?
+ graph.setEdgeWeight(edge, Long.valueOf(d.toMillis()).doubleValue());
+ }
+ // Alternative version if we cannot assume that sequences are ordered by timestamp:
+// if (iv.sequence.stream().max(Comparator.comparing(PcapPacket::getTimestamp)).get()
+// .getTimestamp().isBefore(jv.sequence.stream().min(
+// Comparator.comparing(PcapPacket::getTimestamp)).get().getTimestamp())) {
//
-// }
-
- private Optional<List<PcapPacket>> findSubsequenceInSequence(List<PcapPacket> subsequence,
- List<PcapPacket> sequence,
- Conversation.Direction[] subsequenceDirections,
- Conversation.Direction[] sequenceDirections) {
- if (sequence.size() < subsequence.size()) {
- // If subsequence is longer, it cannot be contained in sequence.
- return Optional.empty();
- }
- if (isTlsSequence(subsequence) != isTlsSequence(sequence)) {
- // We consider it a mismatch if one is a TLS application data sequence and the other is not.
- return Optional.empty();
- }
- // If packet directions have not been precomputed by calling code, we need to construct them.
- if (subsequenceDirections == null) {
- subsequenceDirections = getPacketDirections(subsequence, mRouterWanIp);
- }
- if (sequenceDirections == null) {
- sequenceDirections = getPacketDirections(sequence, mRouterWanIp);
- }
- int subseqIdx = 0;
- int seqIdx = 0;
- while (seqIdx < sequence.size()) {
- PcapPacket subseqPkt = subsequence.get(subseqIdx);
- PcapPacket seqPkt = sequence.get(seqIdx);
- // We only have a match if packet lengths and directions match.
- if (subseqPkt.getOriginalLength() == seqPkt.getOriginalLength() &&
- subsequenceDirections[subseqIdx] == sequenceDirections[seqIdx]) {
- // A match; advance both indices to consider next packet in subsequence vs. next packet in sequence.
- subseqIdx++;
- seqIdx++;
- if (subseqIdx == subsequence.size()) {
- // We managed to match the entire subsequence in sequence.
- // Return the sublist of sequence that matches subsequence.
- /*
- * TODO:
- * ASSUMES THE BACKING LIST (i.e., 'sequence') IS _NOT_ STRUCTURALLY MODIFIED, hence may not work
- * for live traces!
- */
- return Optional.of(sequence.subList(seqIdx - subsequence.size(), seqIdx));
+// }
+ }
+ }
}
- } else {
- // Mismatch.
- if (subseqIdx > 0) {
- /*
- * If we managed to match parts of subsequence, we restart the search for subsequence in sequence at
- * the index of sequence where the current mismatch occurred. I.e., we must reset subseqIdx, but
- * leave seqIdx untouched.
- */
- subseqIdx = 0;
- } else {
- /*
- * First packet of subsequence didn't match packet at seqIdx of sequence, so we move forward in
- * sequence, i.e., we continue the search for subsequence in sequence starting at index seqIdx+1 of
- * sequence.
- */
- seqIdx++;
+ }
+ // Graph construction complete, run shortest-path to find a (potential) signature match.
+ DijkstraShortestPath<Vertex, DefaultWeightedEdge> dijkstra = new DijkstraShortestPath<>(graph);
+ GraphPath<Vertex, DefaultWeightedEdge> shortestPath = dijkstra.getPath(source, sink);
+ if (shortestPath != null) {
+ // The total weight is the duration between the first packet of the first sequence and the last packet
+ // of the last sequence, so we simply have to compare the weight against the timeframe that we allow
+ // the signature to span. For now we just use the inclusion window we defined for training purposes.
+ // Note however, that we must convert back from double to long as the weight is stored as a double in
+ // JGraphT's API.
+ if (((long)shortestPath.getWeight()) < TriggerTrafficExtractor.INCLUSION_WINDOW_MILLIS) {
+ // There's a signature match!
+ // Extract the match from the vertices
+ List<List<PcapPacket>> signatureMatch = new ArrayList<>();
+ for(Vertex v : shortestPath.getVertexList()) {
+ if (v == source || v == sink) {
+ // Skip the dummy source and sink nodes.
+ continue;
+ }
+ signatureMatch.add(v.sequence);
+ // As there is a one-to-one correspondence between vertices[] and pendingMatches[], we know that
+ // the sequence we've "consumed" for index i of the matched signature is also at index i in
+ // pendingMatches. We must remove it from pendingMatches so that we don't use it to construct
+ // another signature match in a later call.
+ pendingMatches[signatureMatch.size()-1].remove(v.sequence);
+ }
+ // Declare success: notify observers
+ mObservers.forEach(obs -> obs.onSignatureDetected(mSignature,
+ Collections.unmodifiableList(signatureMatch)));
}
}
}
- return Optional.empty();
}
/**
- * Given a {@code List<PcapPacket>}, generate a {@code Conversation.Direction[]} such that each entry in the
- * resulting {@code Conversation.Direction[]} specifies the direction of the {@link PcapPacket} at the corresponding
- * index in the input list.
- * @param packets The list of packets for which to construct a corresponding array of packet directions.
- * @param routerWanIp The IP of the router's WAN port. This is used for determining the direction of packets when
- * the traffic is captured just outside the local network (at the ISP side of the router). Set to
- * {@code null} if {@code packets} stem from traffic captured within the local network.
- * @return A {@code Conversation.Direction[]} specifying the direction of the {@link PcapPacket} at the
- * corresponding index in {@code packets}.
+ * Used for registering for notifications of signatures detected by a {@link SignatureDetector}.
*/
- private static Conversation.Direction[] getPacketDirections(List<PcapPacket> packets, String routerWanIp) {
- Conversation.Direction[] directions = new Conversation.Direction[packets.size()];
- for (int i = 0; i < packets.size(); i++) {
- PcapPacket pkt = packets.get(i);
- if (getSourceIp(pkt).equals(getDestinationIp(pkt))) {
- // Sanity check: we shouldn't be processing loopback traffic
- throw new AssertionError("loopback traffic detected");
- }
- if (isSrcIpLocal(pkt) || getSourceIp(pkt).equals(routerWanIp)) {
- directions[i] = Conversation.Direction.CLIENT_TO_SERVER;
- } else if (isDstIpLocal(pkt) || getDestinationIp(pkt).equals(routerWanIp)) {
- directions[i] = Conversation.Direction.SERVER_TO_CLIENT;
- } else {
- throw new IllegalArgumentException("no local IP or router WAN port IP found, can't detect direction");
- }
- }
- return directions;
- }
-
- interface Observer {
-// /**
-// * Callback that is invoked when a sequence associated with the signature/cluster (i.e., the sequence is a
-// * member of the cluster that makes up the signature) is detected in a {@link Conversation}.
-// * @param sequence The sequence that was detected in {@code conversation}.
-// * @param conversation The {@link Conversation} that {@code sequence} was detected in.
-// */
-// void onSequenceDetected(List<PcapPacket> sequence, Conversation conversation);
+ interface SignatureDetectionObserver {
- void onSignatureDetected(List<List<PcapPacket>> signature, List<PcapPacket> match);
+ /**
+ * Invoked when the {@link SignatureDetector} detects the presence of a signature in the traffic that it's
+ * examining.
+ * @param searchedSignature The signature that the {@link SignatureDetector} reporting the match is searching
+ * for.
+ * @param matchingTraffic The actual traffic trace that matches the searched signature.
+ */
+ void onSignatureDetected(List<List<List<PcapPacket>>> searchedSignature,
+ List<List<PcapPacket>> matchingTraffic);
}
+ /**
+ * Encapsulates a {@code List<PcapPacket>} so as to allow the list to be used as a vertex in a graph while avoiding
+ * the expensive {@link AbstractList#equals(Object)} calls when adding vertices to the graph.
+ * Using this wrapper makes the incurred {@code equals(Object)} calls delegate to {@link Object#equals(Object)}
+ * instead of {@link AbstractList#equals(Object)}. The net effect is a faster implementation, but the graph will not
+ * recognize two lists that contain the same items--from a value and not reference point of view--as the same
+ * vertex. However, this is fine for our purposes -- in fact restricting it to reference equality seems more
+ * appropriate.
+ */
+ private static class Vertex {
+ private final List<PcapPacket> sequence;
+ private Vertex(List<PcapPacket> wrappedSequence) {
+ sequence = wrappedSequence;
+ }
+ }
}
projects / pingpong.git / commitdiff