Decode KE payload

This commits:
- Create IkeKePayload class and add a
  constructor for decoding and validating.
- Add IkeKePayloadTest
- Add MessageTestUtil containing commonly used method for
  test files.

Bug: 112044006
Test: FrameworksIkeTests IkeKePayloadTest
Change-Id: Id82cdf8005a4cb5cc3e89e74db7449b22c153e17

3 files changed, 112 insertions, 18 deletions

diff --git a/tests/iketests/src/java/com/android/ike/ikev2/message/IkeKePayloadTest.java b/tests/iketests/src/java/com/android/ike/ikev2/message/IkeKePayloadTest.java
new file mode 100644
index 00000000..cc912218
--- /dev/null
+++ b/tests/iketests/src/java/com/android/ike/ikev2/message/IkeKePayloadTest.java
@@ -0,0 +1,75 @@
+/*
+ * Copyright (C) 2018 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.ikev2.message;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.fail;
+
+import com.android.ike.ikev2.exceptions.InvalidSyntaxException;
+
+import org.junit.Test;
+
+public final class IkeKePayloadTest {
+    private static final String KE_PAYLOAD_RAW_PACKET =
+            "00020000b4a2faf4bb54878ae21d638512ece55d9236fc50"
+                    + "46ab6cef82220f421f3ce6361faf36564ecb6d28798a94aa"
+                    + "d7b2b4b603ddeaaa5630adb9ece8ac37534036040610ebdd"
+                    + "92f46bef84f0be7db860351843858f8acf87056e272377f7"
+                    + "0c9f2d81e29c7b0ce4f291a3a72476bb0b278fd4b7b0a4c2"
+                    + "6bbeb08214c7071376079587";
+
+    private static final boolean CRITICAL_BIT = false;
+    @IkeKePayload.DhGroup
+    private static final int EXPECTED_DH_GROUP = IkeKePayload.DH_GROUP_1024_BIT_MODP;
+
+    private static final String KEY_EXCHANGE_DATA_RAW_PACKET =
+            "b4a2faf4bb54878ae21d638512ece55d9236fc5046ab6cef"
+                    + "82220f421f3ce6361faf36564ecb6d28798a94aad7b2b4b6"
+                    + "03ddeaaa5630adb9ece8ac37534036040610ebdd92f46bef"
+                    + "84f0be7db860351843858f8acf87056e272377f70c9f2d81"
+                    + "e29c7b0ce4f291a3a72476bb0b278fd4b7b0a4c26bbeb082"
+                    + "14c7071376079587";
+
+    @Test
+    public void testDecodeIkeKePayload() throws Exception {
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(KE_PAYLOAD_RAW_PACKET);
+
+        IkeKePayload payload = new IkeKePayload(CRITICAL_BIT, inputPacket);
+
+        assertEquals(EXPECTED_DH_GROUP, payload.dhGroup);
+
+        byte[] keyExchangeData = MessageTestUtil.hexStringToByteArray(KEY_EXCHANGE_DATA_RAW_PACKET);
+        assertEquals(keyExchangeData.length, payload.keyExchangeData.length);
+        for (int i = 0; i < keyExchangeData.length; i++) {
+            assertEquals(keyExchangeData[i], payload.keyExchangeData[i]);
+        }
+    }
+
+    @Test
+    public void testDecodeIkeKePayloadWithInvalidKeData() throws Exception {
+        // Cut bytes of KE data from original KE payload
+        String badKeyPayloadPacket =
+                KE_PAYLOAD_RAW_PACKET.substring(0, KE_PAYLOAD_RAW_PACKET.length() - 2);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(badKeyPayloadPacket);
+
+        try {
+            IkeKePayload payload = new IkeKePayload(CRITICAL_BIT, inputPacket);
+            fail("Expected InvalidSyntaxException: KE data length doesn't match its DH group type");
+        } catch (InvalidSyntaxException expected) {
+        }
+    }
+}
diff --git a/tests/iketests/src/java/com/android/ike/ikev2/message/IkeMessageTest.java b/tests/iketests/src/java/com/android/ike/ikev2/message/IkeMessageTest.java
index 6ca8fdc3..1177d964 100644
--- a/tests/iketests/src/java/com/android/ike/ikev2/message/IkeMessageTest.java
+++ b/tests/iketests/src/java/com/android/ike/ikev2/message/IkeMessageTest.java
@@ -100,7 +100,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testDecodeIkeHeader() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         IkeHeader header = new IkeHeader(inputPacket);
 
         assertEquals(IKE_MSG_LENGTH, inputPacket.length);
@@ -122,7 +122,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testDecodeIkeMessage() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         IkeHeader header = new IkeHeader(inputPacket);
         IkeMessage message = IkeMessage.decode(header, inputPacket);
         assertEquals(SUPPORTED_PAYLOAD_LIST.length, message.ikePayloadList.size());
@@ -133,7 +133,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testDecodeMessageWithUnsupportedUncriticalPayload() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         // Set first payload unsupported uncritical
         inputPacket[FIRST_PAYLOAD_TYPE_POSITION] = (byte) 0xff;
         IkeHeader header = new IkeHeader(inputPacket);
@@ -146,7 +146,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testThrowInvalidMajorVersionException() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         // Set major version 3.
         inputPacket[VERSION_POSITION] = (byte) 0x30;
         // Set Exchange type 0
@@ -164,7 +164,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testThrowInvalidSyntaxException() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         // Set Exchange type 0
         inputPacket[EXCHANGE_TYPE_POSITION] = (byte) 0x00;
         IkeHeader header = new IkeHeader(inputPacket);
@@ -177,7 +177,7 @@ public final class IkeMessageTest {
 
     @Test
     public void testThrowUnsupportedCriticalPayloadException() throws Exception {
-        byte[] inputPacket = hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
+        byte[] inputPacket = MessageTestUtil.hexStringToByteArray(IKE_SA_INIT_RAW_PACKET);
         // Set first payload unsupported critical
         inputPacket[FIRST_PAYLOAD_TYPE_POSITION] = (byte) 0xff;
         inputPacket[IkeHeader.IKE_HEADER_LENGTH + PAYLOAD_CRITICAL_BIT_POSITION] = (byte) 0x80;
@@ -193,18 +193,6 @@ public final class IkeMessageTest {
         }
     }
 
-    private byte[] hexStringToByteArray(String s) {
-        int len = s.length();
-        byte[] data = new byte[len / 2];
-        for (int i = 0; i < len; i += 2) {
-            data[i / 2] =
-                    (byte)
-                            ((Character.digit(s.charAt(i), 16) << 4)
-                                    + Character.digit(s.charAt(i + 1), 16));
-        }
-        return data;
-    }
-
     private boolean support(int payloadType) {
         return (payloadType == IkePayload.PAYLOAD_TYPE_SA
                 || payloadType == IkePayload.PAYLOAD_TYPE_KE
diff --git a/tests/iketests/src/java/com/android/ike/ikev2/message/MessageTestUtil.java b/tests/iketests/src/java/com/android/ike/ikev2/message/MessageTestUtil.java
new file mode 100644
index 00000000..b9544a87
--- /dev/null
+++ b/tests/iketests/src/java/com/android/ike/ikev2/message/MessageTestUtil.java
@@ -0,0 +1,31 @@
+/*
+ * Copyright (C) 2018 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.ikev2.message;
+
+public final class MessageTestUtil {
+    static byte[] hexStringToByteArray(String s) {
+        int len = s.length();
+        byte[] data = new byte[len / 2];
+        for (int i = 0; i < len; i += 2) {
+            data[i / 2] =
+                    (byte)
+                            ((Character.digit(s.charAt(i), 16) << 4)
+                                    + Character.digit(s.charAt(i + 1), 16));
+        }
+        return data;
+    }
+}