1 files changed, 77 insertions, 0 deletions
diff --git a/src/java/com/android/internal/net/eap/message/simaka/EapAkaPrimeAttributeFactory.java b/src/java/com/android/internal/net/eap/message/simaka/EapAkaPrimeAttributeFactory.java
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+/*
+ * 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.internal.net.eap.message.simaka;
+
+import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_KDF;
+import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_KDF_INPUT;
+import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.LENGTH_SCALING;
+
+import com.android.internal.net.eap.exceptions.simaka.EapSimAkaInvalidAttributeException;
+import com.android.internal.net.eap.exceptions.simaka.EapSimAkaUnsupportedAttributeException;
+import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtKdf;
+import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtKdfInput;
+
+import java.nio.ByteBuffer;
+
+/**
+ * EapAkaPrimeAttributeFactory is used for creating EAP-AKA' attributes according to their type.
+ *
+ * @see <a href="https://tools.ietf.org/html/rfc5448">RFC 5448, Improved Extensible Authentication
+ *     Protocol Method for 3rd Generation Authentication and Key Agreement (EAP-AKA')</a>
+ * @see <a href="https://www.iana.org/assignments/eap-numbers/eap-numbers.xhtml">EAP SIM/AKA
+ *     Attributes</a>
+ */
+public class EapAkaPrimeAttributeFactory extends EapAkaAttributeFactory {
+    private static EapAkaPrimeAttributeFactory sInstance = new EapAkaPrimeAttributeFactory();
+
+    private EapAkaPrimeAttributeFactory() {}
+
+    public static EapAkaPrimeAttributeFactory getInstance() {
+        return sInstance;
+    }
+
+    /**
+     * Decodes a single EapSimAkaAttribute object from the given ByteBuffer.
+     *
+     * <p>Decoding logic is based on Attribute definitions in RFC 5448#10.
+     *
+     * @param byteBuffer The ByteBuffer to parse the current attribute from
+     * @return The current EapSimAkaAttribute to be parsed, or EapSimAkaUnsupportedAttribute if the
+     *     given attributeType is skippable and unsupported
+     * @throws EapSimAkaInvalidAttributeException when a malformatted attribute is attempted to be
+     *     decoded
+     * @throws EapSimAkaUnsupportedAttributeException when an unsupported, unskippable Attribute is
+     *     attempted to be decoded
+     */
+    @Override
+    public EapSimAkaAttribute getAttribute(ByteBuffer byteBuffer)
+            throws EapSimAkaInvalidAttributeException, EapSimAkaUnsupportedAttributeException {
+        int attributeType = Byte.toUnsignedInt(byteBuffer.get());
+
+        // Length is given as a multiple of 4x bytes (RFC 4187#8.1)
+        int lengthInBytes = Byte.toUnsignedInt(byteBuffer.get()) * LENGTH_SCALING;
+
+        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);
+        }
+    }
+}