| /* |
| * 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_NONCE_MT; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_RAND; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_SELECTED_VERSION; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_VERSION_LIST; |
| 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.AtNonceMt; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtRandSim; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtSelectedVersion; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtVersionList; |
| |
| import java.nio.ByteBuffer; |
| |
| /** |
| * EapSimAttributeFactory is used for creating EAP-SIM attributes according to their type. |
| * |
| * @see <a href="https://tools.ietf.org/html/rfc4186">RFC 4186, Extensible Authentication |
| * Protocol for Subscriber Identity Modules (EAP-SIM)</a> |
| * @see <a href="https://www.iana.org/assignments/eap-numbers/eap-numbers.xhtml">EAP SIM/AKA |
| * Attributes</a> |
| */ |
| public class EapSimAttributeFactory extends EapSimAkaAttributeFactory { |
| private static EapSimAttributeFactory sInstance = new EapSimAttributeFactory(); |
| |
| private EapSimAttributeFactory() { |
| } |
| |
| public static EapSimAttributeFactory getInstance() { |
| return sInstance; |
| } |
| |
| /** |
| * Decodes a single EapSimAkaAttribute object from the given ByteBuffer. |
| * |
| * <p>Decoding logic is based on Attribute definitions in RFC 4186#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 |
| */ |
| public EapSimAkaAttribute getAttribute(ByteBuffer byteBuffer) throws |
| EapSimAkaInvalidAttributeException, EapSimAkaUnsupportedAttributeException { |
| int attributeType = Byte.toUnsignedInt(byteBuffer.get()); |
| |
| // Length is given as a multiple of 4x bytes (RFC 4186 Section 8.1) |
| int lengthInBytes = Byte.toUnsignedInt(byteBuffer.get()) * LENGTH_SCALING; |
| |
| switch (attributeType) { |
| // TODO(b/134670528): add case statements for all EAP-SIM attributes |
| case EAP_AT_VERSION_LIST: |
| return new AtVersionList(lengthInBytes, byteBuffer); |
| case EAP_AT_SELECTED_VERSION: |
| int selectedVersion = Short.toUnsignedInt(byteBuffer.getShort()); |
| return new AtSelectedVersion(lengthInBytes, selectedVersion); |
| case EAP_AT_NONCE_MT: |
| return new AtNonceMt(lengthInBytes, byteBuffer); |
| case EAP_AT_RAND: |
| return new AtRandSim(lengthInBytes, byteBuffer); |
| default: |
| return super.getAttribute(attributeType, lengthInBytes, byteBuffer); |
| } |
| } |
| } |