-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.*;
-
-/**
- * TODO add class documentation.
- *
- * @author Janus Varmarken {@literal <jvarmark@uci.edu>}
- * @author Rahmadi Trimananda {@literal <rtrimana@uci.edu>}
- */
-public class SignatureDetector 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.serializeClustersFromFile(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")))
- )
- );
-
- PcapHandle handle;
- try {
- handle = Pcaps.openOffline(inputPcapFile, PcapHandle.TimestampPrecision.NANO);
- } catch (PcapNativeException pne) {
- handle = Pcaps.openOffline(inputPcapFile);
- }
- PcapHandleReader reader = new PcapHandleReader(handle, p -> true, signatureDetector);
- reader.readFromHandle();
- signatureDetector.performDetection();
- }
-
- /**
- * The signature that this {@link SignatureDetector} is trying to detect in the observed traffic.
- */
- private final List<List<PcapPacket>> mSignature;
-
- /**
- * The directions of packets in the sequences that make up {@link #mSignature}.
- */
- private final Conversation.Direction[] mSignatureDirections;
-
- /**
- * 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 Observer[] mObservers;
-
- 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)");
- }
- if (mObservers.length == 0) {
- throw new IllegalArgumentException("no detectionObservers provided");
- }
- 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"
- );
- }
- }
-
- @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);
- }
-
-
-// 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?
-// */
-// }
-// }
-
-
- 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;
- }
- // 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();
-//
-// }
-
- 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 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);
-
- void onSignatureDetected(List<List<PcapPacket>> signature, List<PcapPacket> match);
- }
-
-}