Define EAP_AT_KDF attribute for EAP-AKA'.

Bug: 142663198
Test: added AtKdfTest.
Test: atest FrameworksIkeTests
Change-Id: I6b9f6e1fe98c10f4a20f1525409a8340ccfaebdf

4 files changed, 121 insertions, 0 deletions

diff --git a/src/java/com/android/ike/eap/message/simaka/EapAkaPrimeAttributeFactory.java b/src/java/com/android/ike/eap/message/simaka/EapAkaPrimeAttributeFactory.java
index c33b9359..e9086d76 100644
--- a/src/java/com/android/ike/eap/message/simaka/EapAkaPrimeAttributeFactory.java
+++ b/src/java/com/android/ike/eap/message/simaka/EapAkaPrimeAttributeFactory.java
@@ -16,11 +16,13 @@
 
 package com.android.ike.eap.message.simaka;
 
+import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_KDF;
 import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_KDF_INPUT;
 import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.LENGTH_SCALING;
 
 import com.android.ike.eap.exceptions.simaka.EapSimAkaInvalidAttributeException;
 import com.android.ike.eap.exceptions.simaka.EapSimAkaUnsupportedAttributeException;
+import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtKdf;
 import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtKdfInput;
 
 import java.nio.ByteBuffer;
@@ -65,6 +67,8 @@ public class EapAkaPrimeAttributeFactory extends EapAkaAttributeFactory {
         switch (attributeType) {
             case EAP_AT_KDF_INPUT:
                 return new AtKdfInput(lengthInBytes, byteBuffer);
+            case EAP_AT_KDF:
+                return new AtKdf(lengthInBytes, byteBuffer);
             default:
                 return super.getAttribute(attributeType, lengthInBytes, byteBuffer);
         }
diff --git a/src/java/com/android/ike/eap/message/simaka/EapSimAkaAttribute.java b/src/java/com/android/ike/eap/message/simaka/EapSimAkaAttribute.java
index f265d17f..5b6f1726 100644
--- a/src/java/com/android/ike/eap/message/simaka/EapSimAkaAttribute.java
+++ b/src/java/com/android/ike/eap/message/simaka/EapSimAkaAttribute.java
@@ -68,6 +68,7 @@ public abstract class EapSimAkaAttribute {
     public static final int EAP_AT_NONCE_S = 21;
     public static final int EAP_AT_CLIENT_ERROR_CODE = 22;
     public static final int EAP_AT_KDF_INPUT = 23;
+    public static final int EAP_AT_KDF = 24;
 
     // EAP Skippable Attribute values defined by IANA
     // https://www.iana.org/assignments/eapsimaka-numbers/eapsimaka-numbers.xhtml
@@ -99,6 +100,7 @@ public abstract class EapSimAkaAttribute {
         EAP_ATTRIBUTE_STRING.put(EAP_AT_NONCE_S, "AT_NONCE_S");
         EAP_ATTRIBUTE_STRING.put(EAP_AT_CLIENT_ERROR_CODE, "AT_CLIENT_ERROR_CODE");
         EAP_ATTRIBUTE_STRING.put(EAP_AT_KDF_INPUT, "AT_KDF_INPUT");
+        EAP_ATTRIBUTE_STRING.put(EAP_AT_KDF, "AT_KDF");
 
         EAP_ATTRIBUTE_STRING.put(EAP_AT_IV, "AT_IV");
         EAP_ATTRIBUTE_STRING.put(EAP_AT_ENCR_DATA, "AT_ENCR_DATA");
@@ -1085,4 +1087,38 @@ public abstract class EapSimAkaAttribute {
             addPadding(bytesUsed, byteBuffer);
         }
     }
+
+    /**
+     * AdKdf represents the AT_KDF attribute defined in RFC 5448#3.2
+     */
+    public static class AtKdf extends EapSimAkaAttribute {
+        private static final int ATTR_LENGTH = MIN_ATTR_LENGTH;
+
+        public final int kdf;
+
+        public AtKdf(int lengthInBytes, ByteBuffer buffer)
+                throws EapSimAkaInvalidAttributeException {
+            super(EAP_AT_KDF, lengthInBytes);
+
+            if (lengthInBytes != ATTR_LENGTH) {
+                throw new EapSimAkaInvalidAttributeException("AtKdf length must be 4B");
+            }
+
+            kdf = Short.toUnsignedInt(buffer.getShort());
+        }
+
+        @VisibleForTesting
+        public AtKdf(int kdf) throws EapSimAkaInvalidAttributeException {
+            super(EAP_AT_KDF, ATTR_LENGTH);
+
+            this.kdf = kdf;
+        }
+
+        @Override
+        public void encode(ByteBuffer byteBuffer) {
+            encodeAttributeHeader(byteBuffer);
+
+            byteBuffer.putShort((short) kdf);
+        }
+    }
 }
diff --git a/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/AtKdfTest.java b/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/AtKdfTest.java
new file mode 100644
index 00000000..0a1209c8
--- /dev/null
+++ b/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/AtKdfTest.java
@@ -0,0 +1,78 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.ike.eap.message.simaka.attributes;
+
+import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_KDF;
+import static com.android.ike.eap.message.simaka.attributes.EapTestAttributeDefinitions.AT_KDF;
+import static com.android.ike.eap.message.simaka.attributes.EapTestAttributeDefinitions.AT_KDF_INVALID_LENGTH;
+import static com.android.ike.eap.message.simaka.attributes.EapTestAttributeDefinitions.KDF_VERSION;
+
+import static org.junit.Assert.assertArrayEquals;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.fail;
+
+import com.android.ike.eap.exceptions.simaka.EapSimAkaInvalidAttributeException;
+import com.android.ike.eap.message.simaka.EapAkaPrimeAttributeFactory;
+import com.android.ike.eap.message.simaka.EapSimAkaAttribute;
+import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtKdf;
+
+import org.junit.Before;
+import org.junit.Test;
+
+import java.nio.ByteBuffer;
+
+public class AtKdfTest {
+    private EapAkaPrimeAttributeFactory mAttributeFactory;
+
+    @Before
+    public void setUp() {
+        mAttributeFactory = EapAkaPrimeAttributeFactory.getInstance();
+    }
+
+    @Test
+    public void testDecode() throws Exception {
+        ByteBuffer input = ByteBuffer.wrap(AT_KDF);
+        EapSimAkaAttribute result = mAttributeFactory.getAttribute(input);
+
+        assertFalse(input.hasRemaining());
+        AtKdf atKdf = (AtKdf) result;
+        assertEquals(EAP_AT_KDF, atKdf.attributeType);
+        assertEquals(AT_KDF.length, atKdf.lengthInBytes);
+        assertEquals(KDF_VERSION, atKdf.kdf);
+    }
+
+    @Test
+    public void testDecodeInvalidLength() throws Exception {
+        ByteBuffer input = ByteBuffer.wrap(AT_KDF_INVALID_LENGTH);
+        try {
+            mAttributeFactory.getAttribute(input);
+            fail("Expected EapSimAkaInvalidAttributeException for invalid length");
+        } catch (EapSimAkaInvalidAttributeException expected) {
+        }
+    }
+
+    @Test
+    public void testEncode() throws Exception {
+        AtKdf atKdf = new AtKdf(KDF_VERSION);
+        ByteBuffer result = ByteBuffer.allocate(AT_KDF.length);
+
+        atKdf.encode(result);
+        assertArrayEquals(AT_KDF, result.array());
+        assertFalse(result.hasRemaining());
+    }
+}
diff --git a/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/EapTestAttributeDefinitions.java b/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/EapTestAttributeDefinitions.java
index ba30724c..b9007131 100644
--- a/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/EapTestAttributeDefinitions.java
+++ b/tests/iketests/src/java/com/android/ike/eap/message/simaka/attributes/EapTestAttributeDefinitions.java
@@ -80,6 +80,8 @@ public class EapTestAttributeDefinitions {
     public static final byte[] AT_KDF_INPUT =
             hexStringToByteArray("1704000B" + NETWORK_NAME_HEX + "00");
     public static final byte[] AT_KDF_INPUT_EMPTY_NETWORK_NAME = hexStringToByteArray("17010000");
+    public static final int KDF_VERSION = 1;
+    public static final byte[] AT_KDF = hexStringToByteArray("18010001");
 
     public static final byte[] AT_VERSION_LIST_INVALID_LENGTH = hexStringToByteArray("0F020003");
     public static final byte[] AT_SELECTED_VERSION_INVALID_LENGTH =
@@ -110,4 +112,5 @@ public class EapTestAttributeDefinitions {
     public static final byte[] AT_RES_LONG_RES =
             hexStringToByteArray("0306008800112233445566778899AABBCCDDEEFF11000000");
     public static final byte[] AT_AUTS_INVALID_LENGTH = hexStringToByteArray("03010000");
+    public static final byte[] AT_KDF_INVALID_LENGTH = hexStringToByteArray("18020001");
 }