Support converting EapSessionConfig to/from PersistableBundle

Bug: 163604823
Test: FrameworksVcnTests(add new tests)
Change-Id: Iac7077b4ca37dfc07055aac5b3a8118610a27999

core/java/android/net/vcn/persistablebundleutils/EapSessionConfigUtils.java

@@ -0,0 +1,112 @@
+/*
+ * Copyright (C) 2021 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 android.net.vcn.persistablebundleutils;
+
+import static com.android.internal.annotations.VisibleForTesting.Visibility;
+
+import android.annotation.NonNull;
+import android.net.eap.EapSessionConfig;
+import android.net.eap.EapSessionConfig.EapMethodConfig;
+import android.net.eap.EapSessionConfig.EapMsChapV2Config;
+import android.os.PersistableBundle;
+
+import com.android.internal.annotations.VisibleForTesting;
+import com.android.server.vcn.util.PersistableBundleUtils;
+
+import java.util.Objects;
+
+/**
+ * Provides utility methods to convert EapSessionConfig to/from PersistableBundle.
+ *
+ * @hide
+ */
+@VisibleForTesting(visibility = Visibility.PRIVATE)
+public final class EapSessionConfigUtils {
+    private static final String EAP_ID_KEY = "EAP_ID_KEY";
+    private static final String EAP_MSCHAP_V2_CONFIG_KEY = "EAP_MSCHAP_V2_CONFIG_KEY";
+
+    /** Serializes an EapSessionConfig to a PersistableBundle. */
+    @NonNull
+    public static PersistableBundle toPersistableBundle(@NonNull EapSessionConfig config) {
+        final PersistableBundle result = new PersistableBundle();
+
+        result.putPersistableBundle(
+                EAP_ID_KEY, PersistableBundleUtils.fromByteArray(config.getEapIdentity()));
+
+        if (config.getEapMsChapV2Config() != null) {
+            result.putPersistableBundle(
+                    EAP_MSCHAP_V2_CONFIG_KEY,
+                    EapMsChapV2ConfigUtils.toPersistableBundle(config.getEapMsChapV2Config()));
+        }
+
+        // TODO: Handle other EAP methods: EAP-SIM, EAP-AKA, EAP-AKA', EAP-TTLS.
+
+        return result;
+    }
+
+    /** Constructs an EapSessionConfig by deserializing a PersistableBundle. */
+    @NonNull
+    public static EapSessionConfig fromPersistableBundle(@NonNull PersistableBundle in) {
+        Objects.requireNonNull(in, "PersistableBundle was null");
+
+        final EapSessionConfig.Builder builder = new EapSessionConfig.Builder();
+
+        final PersistableBundle eapIdBundle = in.getPersistableBundle(EAP_ID_KEY);
+        Objects.requireNonNull(eapIdBundle, "EAP ID was null");
+        builder.setEapIdentity(PersistableBundleUtils.toByteArray(eapIdBundle));
+
+        final PersistableBundle msChapV2Bundle = in.getPersistableBundle(EAP_MSCHAP_V2_CONFIG_KEY);
+        if (msChapV2Bundle != null) {
+            EapMsChapV2ConfigUtils.setBuilderByReadingPersistableBundle(msChapV2Bundle, builder);
+        }
+
+        // TODO: Handle other EAP methods: EAP-SIM, EAP-AKA, EAP-AKA', EAP-TTLS.
+        return builder.build();
+    }
+
+    private static class EapMethodConfigUtils {
+        private static final String METHOD_TYPE = "METHOD_TYPE";
+
+        /** Serializes an EapMethodConfig to a PersistableBundle. */
+        @NonNull
+        public static PersistableBundle toPersistableBundle(@NonNull EapMethodConfig config) {
+            final PersistableBundle result = new PersistableBundle();
+            result.putInt(METHOD_TYPE, config.getMethodType());
+            return result;
+        }
+    }
+
+    private static final class EapMsChapV2ConfigUtils extends EapMethodConfigUtils {
+        private static final String USERNAME_KEY = "USERNAME_KEY";
+        private static final String PASSWORD_KEY = "PASSWORD_KEY";
+
+        @NonNull
+        public static PersistableBundle toPersistableBundle(@NonNull EapMsChapV2Config config) {
+            final PersistableBundle result = EapMethodConfigUtils.toPersistableBundle(config);
+            result.putString(USERNAME_KEY, config.getUsername());
+            result.putString(PASSWORD_KEY, config.getPassword());
+
+            return result;
+        }
+
+        public static void setBuilderByReadingPersistableBundle(
+                @NonNull PersistableBundle in, @NonNull EapSessionConfig.Builder builder) {
+            Objects.requireNonNull(in, "PersistableBundle was null");
+            builder.setEapMsChapV2Config(in.getString(USERNAME_KEY), in.getString(PASSWORD_KEY));
+        }
+    }
+}

tests/vcn/java/android/net/vcn/persistablebundleutils/EapSessionConfigUtilsTest.java

@@ -0,0 +1,57 @@
+/*
+ * Copyright (C) 2021 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 android.net.vcn.persistablebundleutils;
+
+import static org.junit.Assert.assertEquals;
+
+import android.net.eap.EapSessionConfig;
+import android.os.PersistableBundle;
+
+import androidx.test.filters.SmallTest;
+import androidx.test.runner.AndroidJUnit4;
+
+import org.junit.Test;
+import org.junit.runner.RunWith;
+
+import java.nio.charset.StandardCharsets;
+
+@RunWith(AndroidJUnit4.class)
+@SmallTest
+public class EapSessionConfigUtilsTest {
+    private static final byte[] EAP_ID = "test@android.net".getBytes(StandardCharsets.US_ASCII);
+    private static final String USERNAME = "username";
+    private static final String PASSWORD = "password";
+
+    private EapSessionConfig.Builder createBuilderWithId() {
+        return new EapSessionConfig.Builder().setEapIdentity(EAP_ID);
+    }
+
+    private static void verifyPersistableBundleEncodeDecodeIsLossless(EapSessionConfig config) {
+        final PersistableBundle bundle = EapSessionConfigUtils.toPersistableBundle(config);
+        final EapSessionConfig resultConfig = EapSessionConfigUtils.fromPersistableBundle(bundle);
+
+        assertEquals(config, resultConfig);
+    }
+
+    @Test
+    public void testSetEapMsChapV2EncodeDecodeIsLossless() throws Exception {
+        final EapSessionConfig config =
+                createBuilderWithId().setEapMsChapV2Config(USERNAME, PASSWORD).build();
+
+        verifyPersistableBundleEncodeDecodeIsLossless(config);
+    }
+}