Terminate IKE SA when hard lifetime alarm fires

Bug: 147831323
Test: atest FrameworksIkeTests
Test: Manually test against Strongswan IKE server
Change-Id: I028846d5af8c198a804e07da2623bb2d68905778

4 files changed, 155 insertions, 19 deletions

diff --git a/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachine.java b/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachine.java
index 68133614..c64e83b7 100644
--- a/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachine.java
+++ b/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachine.java
@@ -90,6 +90,7 @@ import com.android.internal.net.ipsec.ike.IkeLocalRequestScheduler.ChildLocalReq
 import com.android.internal.net.ipsec.ike.IkeLocalRequestScheduler.IkeLocalRequest;
 import com.android.internal.net.ipsec.ike.IkeLocalRequestScheduler.LocalRequest;
 import com.android.internal.net.ipsec.ike.SaRecord.IkeSaRecord;
+import com.android.internal.net.ipsec.ike.SaRecord.SaLifetimeAlarmScheduler;
 import com.android.internal.net.ipsec.ike.crypto.IkeCipher;
 import com.android.internal.net.ipsec.ike.crypto.IkeMacIntegrity;
 import com.android.internal.net.ipsec.ike.crypto.IkeMacPrf;
@@ -1235,6 +1236,28 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
         return obtainMessage(CMD_ALARM_FIRED, mIkeSessionId, localRequestType, spiBundle);
     }
 
+    private SaLifetimeAlarmScheduler buildSaLifetimeAlarmScheduler(long remoteSpi) {
+        PendingIntent deleteSaIntent =
+                buildIkeAlarmIntent(
+                        mContext,
+                        ACTION_DELETE_IKE,
+                        getIntentIdentifier(remoteSpi),
+                        getIntentIkeSmMsg(CMD_LOCAL_REQUEST_DELETE_IKE, remoteSpi));
+        PendingIntent rekeySaIntent =
+                buildIkeAlarmIntent(
+                        mContext,
+                        ACTION_REKEY_IKE,
+                        getIntentIdentifier(remoteSpi),
+                        getIntentIkeSmMsg(CMD_LOCAL_REQUEST_REKEY_IKE, remoteSpi));
+
+        return new SaLifetimeAlarmScheduler(
+                mIkeSessionParams.getHardLifetimeMsInternal(),
+                mIkeSessionParams.getSoftLifetimeMsInternal(),
+                deleteSaIntent,
+                rekeySaIntent,
+                mAlarmManager);
+    }
+
     // Package private. Accessible to ChildSessionStateMachine
     static PendingIntent buildIkeAlarmIntent(
             Context context, String intentAction, String intentId, Message ikeSmMsg) {
@@ -1479,12 +1502,13 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
 
         protected void handleFiredAlarm(Message message) {
             switch (message.arg2) {
+                case CMD_LOCAL_REQUEST_DELETE_IKE:
+                    // IKE SA hits its hard lifetime
+                    enqueueIkeLocalRequest(message);
+                    return;
                 case CMD_LOCAL_REQUEST_DPD:
                     // IKE Session has not received any protectd IKE packet for the whole DPD delay
-                    long remoteIkeSpi = ((Bundle) message.obj).getLong(BUNDLE_KEY_IKE_REMOTE_SPI);
-                    sendMessage(
-                            CMD_LOCAL_REQUEST_DPD,
-                            new IkeLocalRequest(CMD_LOCAL_REQUEST_DPD, remoteIkeSpi));
+                    enqueueIkeLocalRequest(message);
 
                     // TODO(b/152442041): Cancel the scheduled DPD request if IKE Session starts any
                     // procedure before DPD get executed.
@@ -1494,6 +1518,11 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
             }
             // TODO: Handle delete and rekey IKE/Child SA
         }
+
+        private void enqueueIkeLocalRequest(Message message) {
+            long remoteIkeSpi = ((Bundle) message.obj).getLong(BUNDLE_KEY_IKE_REMOTE_SPI);
+            sendMessage(message.arg2, new IkeLocalRequest(message.arg2, remoteIkeSpi));
+        }
     }
 
     /**
@@ -2660,7 +2689,8 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
                                 mIkePrf,
                                 mIkeIntegrity == null ? 0 : mIkeIntegrity.getKeyLength(),
                                 mIkeCipher.getKeyLength(),
-                                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE));
+                                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE),
+                                buildSaLifetimeAlarmScheduler(mRemoteIkeSpiResource.getSpi()));
 
                 addIkeSaRecord(mCurrentIkeSaRecord);
                 ikeInitSuccess = true;
@@ -3805,6 +3835,10 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
                 newPrf = IkeMacPrf.create(respProposal.saProposal.getPrfTransforms()[0]);
 
                 // Build new SaRecord
+                long remoteSpi =
+                        isLocalInit
+                                ? respProposal.getIkeSpiResource().getSpi()
+                                : reqProposal.getIkeSpiResource().getSpi();
                 IkeSaRecord newSaRecord =
                         IkeSaRecord.makeRekeyedIkeSaRecord(
                                 mCurrentIkeSaRecord,
@@ -3817,8 +3851,8 @@ public class IkeSessionStateMachine extends AbstractSessionStateMachine {
                                 newIntegrity == null ? 0 : newIntegrity.getKeyLength(),
                                 newCipher.getKeyLength(),
                                 isLocalInit,
-                                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE));
-
+                                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE),
+                                buildSaLifetimeAlarmScheduler(remoteSpi));
                 addIkeSaRecord(newSaRecord);
 
                 mIkeCipher = newCipher;
diff --git a/src/java/com/android/internal/net/ipsec/ike/SaRecord.java b/src/java/com/android/internal/net/ipsec/ike/SaRecord.java
index ca8f4757..25cc740c 100644
--- a/src/java/com/android/internal/net/ipsec/ike/SaRecord.java
+++ b/src/java/com/android/internal/net/ipsec/ike/SaRecord.java
@@ -18,6 +18,8 @@ package com.android.internal.net.ipsec.ike;
 import static android.net.ipsec.ike.IkeManager.getIkeLog;
 
 import android.annotation.Nullable;
+import android.app.AlarmManager;
+import android.app.PendingIntent;
 import android.content.Context;
 import android.net.IpSecManager;
 import android.net.IpSecManager.ResourceUnavailableException;
@@ -25,6 +27,7 @@ import android.net.IpSecManager.SecurityParameterIndex;
 import android.net.IpSecManager.SpiUnavailableException;
 import android.net.IpSecManager.UdpEncapsulationSocket;
 import android.net.IpSecTransform;
+import android.os.SystemClock;
 import android.util.CloseGuard;
 
 import com.android.internal.annotations.VisibleForTesting;
@@ -79,6 +82,9 @@ public abstract class SaRecord implements AutoCloseable {
     private final byte[] mSkEi;
     private final byte[] mSkEr;
 
+    private final SaLifetimeAlarmScheduler mSaLifetimeAlarmScheduler;
+
+    // TODO(b/149058810): Use AlarmManager and PendingIntent to schedule rekey
     private final LocalRequest mFutureRekeyEvent;
 
     private final CloseGuard mCloseGuard = new CloseGuard();
@@ -92,7 +98,8 @@ public abstract class SaRecord implements AutoCloseable {
             byte[] skAr,
             byte[] skEi,
             byte[] skEr,
-            LocalRequest futureRekeyEvent) {
+            LocalRequest futureRekeyEvent,
+            SaLifetimeAlarmScheduler saLifetimeAlarmScheduler) {
         isLocalInit = localInit;
         nonceInitiator = nonceInit;
         nonceResponder = nonceResp;
@@ -107,6 +114,15 @@ public abstract class SaRecord implements AutoCloseable {
         logKey("SK_ei", skEi);
         logKey("SK_er", skEr);
 
+        mSaLifetimeAlarmScheduler = saLifetimeAlarmScheduler;
+
+        // TODO(b/147831323): Remove this condition check after we pass in a real
+        // saLifetimeAlarmScheduler to ChildSaRecord
+        if (mSaLifetimeAlarmScheduler != null) {
+            mSaLifetimeAlarmScheduler.scheduleLifetimeExpiryAlarm(getTag());
+        }
+
+        // TODO(b/149058810): Use alarmManager to schedule rekey event and remove mFutureRekeyEvent
         mFutureRekeyEvent = futureRekeyEvent;
 
         mCloseGuard.open("close");
@@ -168,6 +184,12 @@ public abstract class SaRecord implements AutoCloseable {
     @Override
     public void close() {
         mFutureRekeyEvent.cancel();
+
+        // TODO(b/147831323): Remove this condition check after we pass in a real
+        // saLifetimeAlarmScheduler to ChildSaRecord
+        if (mSaLifetimeAlarmScheduler != null) {
+            mSaLifetimeAlarmScheduler.cancelLifetimeExpiryAlarm(getTag());
+        }
     }
 
     /** Package private */
@@ -323,7 +345,8 @@ public abstract class SaRecord implements AutoCloseable {
                     skEr,
                     skPi,
                     skPr,
-                    ikeSaRecordConfig.futureRekeyEvent);
+                    ikeSaRecordConfig.futureRekeyEvent,
+                    ikeSaRecordConfig.saLifetimeAlarmScheduler);
         }
 
         @Override
@@ -514,6 +537,52 @@ public abstract class SaRecord implements AutoCloseable {
         }
     }
 
+    /** This class provides methods to schedule and cancel SA lifetime expiry alarm */
+    static class SaLifetimeAlarmScheduler {
+        private final long mDeleteDelayMs;
+        private final long mRekeyDelayMs;
+        private final PendingIntent mDeleteSaIntent;
+        private final PendingIntent mRekeySaIntent;
+        private final AlarmManager mAlarmManager;
+
+        SaLifetimeAlarmScheduler(
+                long deleteDelayMs,
+                long rekeyDelayMs,
+                PendingIntent deleteSaIntent,
+                PendingIntent rekeySaIntent,
+                AlarmManager alarmManager) {
+            mDeleteDelayMs = deleteDelayMs;
+            mRekeyDelayMs = rekeyDelayMs;
+            mAlarmManager = alarmManager;
+            mDeleteSaIntent = deleteSaIntent;
+            mRekeySaIntent = rekeySaIntent;
+        }
+
+        public void scheduleLifetimeExpiryAlarm(String tag) {
+            // Hard lifetime expiry alarm needs to be "setExact" considering the hard lifetime
+            // minimum value is 5 minutes and the inexact alarm might cause at most 75% of the
+            // scheduled interval delay because batching alarms. It is not necessay to wake up the
+            // alarm during doze mode because even the SA expires at that time, the device can not
+            // get access to network and won't expose more vulnerabilities.
+            mAlarmManager.setExact(
+                    AlarmManager.ELAPSED_REALTIME_WAKEUP,
+                    SystemClock.elapsedRealtime() + mDeleteDelayMs,
+                    mDeleteSaIntent);
+            getIkeLog().d(tag, "Hard lifetime expiry alarm set for " + mDeleteDelayMs + "ms");
+
+            // TODO: Schedule alarm for rekey
+        }
+
+        public void cancelLifetimeExpiryAlarm(String tag) {
+            mAlarmManager.cancel(mDeleteSaIntent);
+            mAlarmManager.cancel(mRekeySaIntent);
+            mDeleteSaIntent.cancel();
+            mRekeySaIntent.cancel();
+
+            getIkeLog().d(tag, "Hard and soft lifetime alarm cancelled");
+        }
+    }
+
     /** Package private class to group parameters for building a ChildSaRecord. */
     @VisibleForTesting
     static final class ChildSaRecordConfig {
@@ -599,8 +668,18 @@ public abstract class SaRecord implements AutoCloseable {
                 byte[] skEr,
                 byte[] skPi,
                 byte[] skPr,
-                LocalRequest futureRekeyEvent) {
-            super(localInit, nonceInit, nonceResp, skAi, skAr, skEi, skEr, futureRekeyEvent);
+                LocalRequest futureRekeyEvent,
+                SaLifetimeAlarmScheduler saLifetimeAlarmScheduler) {
+            super(
+                    localInit,
+                    nonceInit,
+                    nonceResp,
+                    skAi,
+                    skAr,
+                    skEi,
+                    skEr,
+                    futureRekeyEvent,
+                    saLifetimeAlarmScheduler);
 
             mInitiatorSpiResource = initSpi;
             mResponderSpiResource = respSpi;
@@ -632,7 +711,8 @@ public abstract class SaRecord implements AutoCloseable {
                 IkeMacPrf prf,
                 int integrityKeyLength,
                 int encryptionKeyLength,
-                LocalRequest futureRekeyEvent)
+                LocalRequest futureRekeyEvent,
+                SaLifetimeAlarmScheduler saLifetimeAlarmScheduler)
                 throws GeneralSecurityException {
             return sSaRecordHelper.makeFirstIkeSaRecord(
                     initRequest,
@@ -644,7 +724,8 @@ public abstract class SaRecord implements AutoCloseable {
                             integrityKeyLength,
                             encryptionKeyLength,
                             true /*isLocalInit*/,
-                            futureRekeyEvent));
+                            futureRekeyEvent,
+                            saLifetimeAlarmScheduler));
         }
 
         /** Package private */
@@ -659,7 +740,8 @@ public abstract class SaRecord implements AutoCloseable {
                 int integrityKeyLength,
                 int encryptionKeyLength,
                 boolean isLocalInit,
-                LocalRequest futureRekeyEvent)
+                LocalRequest futureRekeyEvent,
+                SaLifetimeAlarmScheduler saLifetimeAlarmScheduler)
                 throws GeneralSecurityException {
             return sSaRecordHelper.makeRekeyedIkeSaRecord(
                     oldSaRecord,
@@ -673,7 +755,8 @@ public abstract class SaRecord implements AutoCloseable {
                             integrityKeyLength,
                             encryptionKeyLength,
                             isLocalInit,
-                            futureRekeyEvent));
+                            futureRekeyEvent,
+                            saLifetimeAlarmScheduler));
         }
 
         private void logKey(String type, byte[] key) {
@@ -852,6 +935,7 @@ public abstract class SaRecord implements AutoCloseable {
         public final int encryptionKeyLength;
         public final boolean isLocalInit;
         public final LocalRequest futureRekeyEvent;
+        public final SaLifetimeAlarmScheduler saLifetimeAlarmScheduler;
 
         IkeSaRecordConfig(
                 IkeSecurityParameterIndex initSpi,
@@ -860,7 +944,8 @@ public abstract class SaRecord implements AutoCloseable {
                 int integrityKeyLength,
                 int encryptionKeyLength,
                 boolean isLocalInit,
-                LocalRequest futureRekeyEvent) {
+                LocalRequest futureRekeyEvent,
+                SaLifetimeAlarmScheduler saLifetimeAlarmScheduler) {
             this.initSpi = initSpi;
             this.respSpi = respSpi;
             this.prf = prf;
@@ -868,6 +953,7 @@ public abstract class SaRecord implements AutoCloseable {
             this.encryptionKeyLength = encryptionKeyLength;
             this.isLocalInit = isLocalInit;
             this.futureRekeyEvent = futureRekeyEvent;
+            this.saLifetimeAlarmScheduler = saLifetimeAlarmScheduler;
         }
     }
 
@@ -899,7 +985,19 @@ public abstract class SaRecord implements AutoCloseable {
                 IpSecTransform inTransform,
                 IpSecTransform outTransform,
                 ChildLocalRequest futureRekeyEvent) {
-            super(localInit, nonceInit, nonceResp, skAi, skAr, skEi, skEr, futureRekeyEvent);
+            super(
+                    localInit,
+                    nonceInit,
+                    nonceResp,
+                    skAi,
+                    skAr,
+                    skEi,
+                    skEr,
+                    futureRekeyEvent,
+                    null /*saLifetimeAlarmScheduler*/);
+
+            // TODO(b/147831323): Build a saLifetimeAlarmScheduler in ChildSessionStateMachine and
+            // pass it to ChildSaRecord
 
             mInboundSpi = inSpi;
             mOutboundSpi = outSpi;
diff --git a/tests/iketests/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachineTest.java b/tests/iketests/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachineTest.java
index 119cf2ab..5f25cbae 100644
--- a/tests/iketests/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachineTest.java
+++ b/tests/iketests/src/java/com/android/internal/net/ipsec/ike/IkeSessionStateMachineTest.java
@@ -107,6 +107,7 @@ import com.android.internal.net.ipsec.ike.IkeSessionStateMachine.ReceivedIkePack
 import com.android.internal.net.ipsec.ike.SaRecord.ISaRecordHelper;
 import com.android.internal.net.ipsec.ike.SaRecord.IkeSaRecord;
 import com.android.internal.net.ipsec.ike.SaRecord.IkeSaRecordConfig;
+import com.android.internal.net.ipsec.ike.SaRecord.SaLifetimeAlarmScheduler;
 import com.android.internal.net.ipsec.ike.SaRecord.SaRecordHelper;
 import com.android.internal.net.ipsec.ike.crypto.IkeCipher;
 import com.android.internal.net.ipsec.ike.crypto.IkeMacIntegrity;
@@ -638,7 +639,8 @@ public final class IkeSessionStateMachineTest {
                 new byte[KEY_LEN_IKE_ENCR],
                 TestUtils.hexStringToByteArray(PRF_KEY_INIT_HEX_STRING),
                 TestUtils.hexStringToByteArray(PRF_KEY_RESP_HEX_STRING),
-                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE));
+                new IkeLocalRequest(CMD_LOCAL_REQUEST_REKEY_IKE),
+                mock(SaLifetimeAlarmScheduler.class));
     }
 
     @Before
diff --git a/tests/iketests/src/java/com/android/internal/net/ipsec/ike/SaRecordTest.java b/tests/iketests/src/java/com/android/internal/net/ipsec/ike/SaRecordTest.java
index 869c5636..97704701 100644
--- a/tests/iketests/src/java/com/android/internal/net/ipsec/ike/SaRecordTest.java
+++ b/tests/iketests/src/java/com/android/internal/net/ipsec/ike/SaRecordTest.java
@@ -45,6 +45,7 @@ import com.android.internal.net.ipsec.ike.SaRecord.IIpSecTransformHelper;
 import com.android.internal.net.ipsec.ike.SaRecord.IkeSaRecord;
 import com.android.internal.net.ipsec.ike.SaRecord.IkeSaRecordConfig;
 import com.android.internal.net.ipsec.ike.SaRecord.IpSecTransformHelper;
+import com.android.internal.net.ipsec.ike.SaRecord.SaLifetimeAlarmScheduler;
 import com.android.internal.net.ipsec.ike.SaRecord.SaRecordHelper;
 import com.android.internal.net.ipsec.ike.crypto.IkeCipher;
 import com.android.internal.net.ipsec.ike.crypto.IkeMacIntegrity;
@@ -184,7 +185,8 @@ public final class SaRecordTest {
                         IKE_AUTH_ALGO_KEY_LEN,
                         IKE_ENCR_ALGO_KEY_LEN,
                         true /*isLocalInit*/,
-                        mMockFutureRekeyIkeEvent);
+                        mMockFutureRekeyIkeEvent,
+                        mock(SaLifetimeAlarmScheduler.class));
 
         int keyMaterialLen =
                 IKE_SK_D_KEY_LEN