diff --git a/core/java/android/net/IpSecAlgorithm.java b/core/java/android/net/IpSecAlgorithm.java
index c69a4d4c0b..d9ac981959 100644
--- a/core/java/android/net/IpSecAlgorithm.java
+++ b/core/java/android/net/IpSecAlgorithm.java
@@ -122,7 +122,7 @@ public final class IpSecAlgorithm implements Parcelable {
      * @param algorithm name of the algorithm.
      * @param key key padded to a multiple of 8 bits.
      */
-    public IpSecAlgorithm(@AlgorithmName String algorithm, @NonNull byte[] key) {
+    public IpSecAlgorithm(@NonNull @AlgorithmName String algorithm, @NonNull byte[] key) {
         this(algorithm, key, key.length * 8);
     }
 
@@ -137,7 +137,8 @@ public final class IpSecAlgorithm implements Parcelable {
      * @param key key padded to a multiple of 8 bits.
      * @param truncLenBits number of bits of output hash to use.
      */
-    public IpSecAlgorithm(@AlgorithmName String algorithm, @NonNull byte[] key, int truncLenBits) {
+    public IpSecAlgorithm(
+            @NonNull @AlgorithmName String algorithm, @NonNull byte[] key, int truncLenBits) {
         mName = algorithm;
         mKey = key.clone();
         mTruncLenBits = truncLenBits;
@@ -145,11 +146,13 @@ public final class IpSecAlgorithm implements Parcelable {
     }
 
     /** Get the algorithm name */
+    @NonNull
     public String getName() {
         return mName;
     }
 
     /** Get the key for this algorithm */
+    @NonNull
     public byte[] getKey() {
         return mKey.clone();
     }
@@ -263,6 +266,7 @@ public final class IpSecAlgorithm implements Parcelable {
     }
 
     @Override
+    @NonNull
     public String toString() {
         return new StringBuilder()
                 .append("{mName=")
diff --git a/core/java/android/net/IpSecManager.java b/core/java/android/net/IpSecManager.java
index cb4299ef69..4157845d61 100644
--- a/core/java/android/net/IpSecManager.java
+++ b/core/java/android/net/IpSecManager.java
@@ -253,8 +253,9 @@ public final class IpSecManager {
      * @throws {@link #ResourceUnavailableException} indicating that too many SPIs are
      *     currently allocated for this user
      */
-    public SecurityParameterIndex allocateSecurityParameterIndex(InetAddress destinationAddress)
-            throws ResourceUnavailableException {
+    @NonNull
+    public SecurityParameterIndex allocateSecurityParameterIndex(
+                @NonNull InetAddress destinationAddress) throws ResourceUnavailableException {
         try {
             return new SecurityParameterIndex(
                     mService,
@@ -280,8 +281,9 @@ public final class IpSecManager {
      * @throws {@link #SpiUnavailableException} indicating that the requested SPI could not be
      *     reserved
      */
+    @NonNull
     public SecurityParameterIndex allocateSecurityParameterIndex(
-            InetAddress destinationAddress, int requestedSpi)
+            @NonNull InetAddress destinationAddress, int requestedSpi)
             throws SpiUnavailableException, ResourceUnavailableException {
         if (requestedSpi == IpSecManager.INVALID_SECURITY_PARAMETER_INDEX) {
             throw new IllegalArgumentException("Requested SPI must be a valid (non-zero) SPI");
@@ -318,9 +320,8 @@ public final class IpSecManager {
      * @param transform a transport mode {@code IpSecTransform}
      * @throws IOException indicating that the transform could not be applied
      */
-    public void applyTransportModeTransform(
-            Socket socket, @PolicyDirection int direction, IpSecTransform transform)
-            throws IOException {
+    public void applyTransportModeTransform(@NonNull Socket socket,
+            @PolicyDirection int direction, @NonNull IpSecTransform transform) throws IOException {
         applyTransportModeTransform(socket.getFileDescriptor$(), direction, transform);
     }
 
@@ -353,9 +354,8 @@ public final class IpSecManager {
      * @param transform a transport mode {@code IpSecTransform}
      * @throws IOException indicating that the transform could not be applied
      */
-    public void applyTransportModeTransform(
-            DatagramSocket socket, @PolicyDirection int direction, IpSecTransform transform)
-            throws IOException {
+    public void applyTransportModeTransform(@NonNull DatagramSocket socket,
+            @PolicyDirection int direction, @NonNull IpSecTransform transform) throws IOException {
         applyTransportModeTransform(socket.getFileDescriptor$(), direction, transform);
     }
 
@@ -388,9 +388,8 @@ public final class IpSecManager {
      * @param transform a transport mode {@code IpSecTransform}
      * @throws IOException indicating that the transform could not be applied
      */
-    public void applyTransportModeTransform(
-            FileDescriptor socket, @PolicyDirection int direction, IpSecTransform transform)
-            throws IOException {
+    public void applyTransportModeTransform(@NonNull FileDescriptor socket,
+            @PolicyDirection int direction, @NonNull IpSecTransform transform) throws IOException {
         // We dup() the FileDescriptor here because if we don't, then the ParcelFileDescriptor()
         // constructor takes control and closes the user's FD when we exit the method.
         try (ParcelFileDescriptor pfd = ParcelFileDescriptor.dup(socket)) {
@@ -413,8 +412,7 @@ public final class IpSecManager {
      * @param socket a socket that previously had a transform applied to it
      * @throws IOException indicating that the transform could not be removed from the socket
      */
-    public void removeTransportModeTransforms(Socket socket)
-            throws IOException {
+    public void removeTransportModeTransforms(@NonNull Socket socket) throws IOException {
         removeTransportModeTransforms(socket.getFileDescriptor$());
     }
 
@@ -431,8 +429,7 @@ public final class IpSecManager {
      * @param socket a socket that previously had a transform applied to it
      * @throws IOException indicating that the transform could not be removed from the socket
      */
-    public void removeTransportModeTransforms(DatagramSocket socket)
-            throws IOException {
+    public void removeTransportModeTransforms(@NonNull DatagramSocket socket) throws IOException {
         removeTransportModeTransforms(socket.getFileDescriptor$());
     }
 
@@ -449,8 +446,7 @@ public final class IpSecManager {
      * @param socket a socket that previously had a transform applied to it
      * @throws IOException indicating that the transform could not be removed from the socket
      */
-    public void removeTransportModeTransforms(FileDescriptor socket)
-            throws IOException {
+    public void removeTransportModeTransforms(@NonNull FileDescriptor socket) throws IOException {
         try (ParcelFileDescriptor pfd = ParcelFileDescriptor.dup(socket)) {
             mService.removeTransportModeTransforms(pfd);
         } catch (RemoteException e) {
@@ -588,6 +584,7 @@ public final class IpSecManager {
     // safely usable for Encapsulation without allowing a user to possibly unbind from/close
     // the port, which could potentially impact the traffic of the next user who binds to that
     // socket.
+    @NonNull
     public UdpEncapsulationSocket openUdpEncapsulationSocket(int port)
             throws IOException, ResourceUnavailableException {
         /*
@@ -617,6 +614,7 @@ public final class IpSecManager {
     // safely usable for Encapsulation without allowing a user to possibly unbind from/close
     // the port, which could potentially impact the traffic of the next user who binds to that
     // socket.
+    @NonNull
     public UdpEncapsulationSocket openUdpEncapsulationSocket()
             throws IOException, ResourceUnavailableException {
         return new UdpEncapsulationSocket(mService, 0);
@@ -645,6 +643,7 @@ public final class IpSecManager {
         private int mResourceId = INVALID_RESOURCE_ID;
 
         /** Get the underlying SPI held by this object. */
+        @NonNull
         public String getInterfaceName() {
             return mInterfaceName;
         }
@@ -659,7 +658,7 @@ public final class IpSecManager {
          * @hide
          */
         @SystemApi
-        public void addAddress(LinkAddress address) throws IOException {
+        public void addAddress(@NonNull LinkAddress address) throws IOException {
             try {
                 mService.addAddressToTunnelInterface(mResourceId, address);
             } catch (RemoteException e) {
@@ -676,7 +675,7 @@ public final class IpSecManager {
          * @hide
          */
         @SystemApi
-        public void removeAddress(LinkAddress address) throws IOException {
+        public void removeAddress(@NonNull LinkAddress address) throws IOException {
             try {
                 mService.removeAddressFromTunnelInterface(mResourceId, address);
             } catch (RemoteException e) {
@@ -768,6 +767,7 @@ public final class IpSecManager {
      * @hide
      */
     @SystemApi
+    @NonNull
     @RequiresPermission(android.Manifest.permission.NETWORK_STACK)
     public IpSecTunnelInterface createIpSecTunnelInterface(@NonNull InetAddress localAddress,
             @NonNull InetAddress remoteAddress, @NonNull Network underlyingNetwork)
@@ -794,8 +794,8 @@ public final class IpSecManager {
      */
     @SystemApi
     @RequiresPermission(android.Manifest.permission.NETWORK_STACK)
-    public void applyTunnelModeTransform(IpSecTunnelInterface tunnel,
-            @PolicyDirection int direction, IpSecTransform transform) throws IOException {
+    public void applyTunnelModeTransform(@NonNull IpSecTunnelInterface tunnel,
+            @PolicyDirection int direction, @NonNull IpSecTransform transform) throws IOException {
         try {
             mService.applyTunnelModeTransform(
                     tunnel.getResourceId(), direction, transform.getResourceId());
diff --git a/core/java/android/net/IpSecTransform.java b/core/java/android/net/IpSecTransform.java
index 60e96f9434..cf58647bbb 100644
--- a/core/java/android/net/IpSecTransform.java
+++ b/core/java/android/net/IpSecTransform.java
@@ -350,6 +350,7 @@ public final class IpSecTransform implements AutoCloseable {
          *
          * @param algo {@link IpSecAlgorithm} specifying the encryption to be applied.
          */
+        @NonNull
         public IpSecTransform.Builder setEncryption(@NonNull IpSecAlgorithm algo) {
             // TODO: throw IllegalArgumentException if algo is not an encryption algorithm.
             Preconditions.checkNotNull(algo);
@@ -364,6 +365,7 @@ public final class IpSecTransform implements AutoCloseable {
          *
          * @param algo {@link IpSecAlgorithm} specifying the authentication to be applied.
          */
+        @NonNull
         public IpSecTransform.Builder setAuthentication(@NonNull IpSecAlgorithm algo) {
             // TODO: throw IllegalArgumentException if algo is not an authentication algorithm.
             Preconditions.checkNotNull(algo);
@@ -384,6 +386,7 @@ public final class IpSecTransform implements AutoCloseable {
          * @param algo {@link IpSecAlgorithm} specifying the authenticated encryption algorithm to
          *     be applied.
          */
+        @NonNull
         public IpSecTransform.Builder setAuthenticatedEncryption(@NonNull IpSecAlgorithm algo) {
             Preconditions.checkNotNull(algo);
             mConfig.setAuthenticatedEncryption(algo);
@@ -403,6 +406,7 @@ public final class IpSecTransform implements AutoCloseable {
          * @param remotePort the UDP port number of the remote host that will send and receive
          *     encapsulated traffic. In the case of IKEv2, this should be port 4500.
          */
+        @NonNull
         public IpSecTransform.Builder setIpv4Encapsulation(
                 @NonNull IpSecManager.UdpEncapsulationSocket localSocket, int remotePort) {
             Preconditions.checkNotNull(localSocket);
@@ -436,6 +440,7 @@ public final class IpSecTransform implements AutoCloseable {
          *     collides with an existing transform
          * @throws IOException indicating other errors
          */
+        @NonNull
         public IpSecTransform buildTransportModeTransform(
                 @NonNull InetAddress sourceAddress,
                 @NonNull IpSecManager.SecurityParameterIndex spi)
@@ -472,6 +477,7 @@ public final class IpSecTransform implements AutoCloseable {
          * @hide
          */
         @SystemApi
+        @NonNull
         @RequiresPermission(android.Manifest.permission.NETWORK_STACK)
         public IpSecTransform buildTunnelModeTransform(
                 @NonNull InetAddress sourceAddress,