| /* |
| * 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_ANY_ID_REQ; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_CLIENT_ERROR_CODE; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_COUNTER; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_COUNTER_TOO_SMALL; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_FULLAUTH_ID_REQ; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_IDENTITY; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_MAC; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_NONCE_S; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_NOTIFICATION; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_PADDING; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EAP_AT_PERMANENT_ID_REQ; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.LENGTH_SCALING; |
| import static com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.SKIPPABLE_ATTRIBUTE_RANGE_START; |
| |
| import com.android.internal.annotations.VisibleForTesting; |
| 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.AtAnyIdReq; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtClientErrorCode; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtCounter; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtCounterTooSmall; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtFullauthIdReq; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtIdentity; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtMac; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtNonceS; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtNotification; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtPadding; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.AtPermanentIdReq; |
| import com.android.internal.net.eap.message.simaka.EapSimAkaAttribute.EapSimAkaUnsupportedAttribute; |
| |
| import java.nio.ByteBuffer; |
| |
| /** |
| * EapSimAkaAttributeFactory is used for creating EapSimAkaAttributes 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://tools.ietf.org/html/rfc4187">RFC 4187, Extensible Authentication |
| * Protocol for 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 abstract class EapSimAkaAttributeFactory { |
| /** |
| * Decodes a single EapSimAkaAttribute object from the given ByteBuffer. |
| * |
| * <p>Decoding logic is based on Attribute definitions in RFC 4186#10 and RFC 4187#10. |
| * |
| * @param attributeType the attribute type to be decoded |
| * @param lengthInBytes the length in bytes of the attribute to be decoded |
| * @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 |
| */ |
| EapSimAkaAttribute getAttribute(int attributeType, int lengthInBytes, ByteBuffer byteBuffer) |
| throws EapSimAkaInvalidAttributeException, EapSimAkaUnsupportedAttributeException { |
| switch (attributeType) { |
| // TODO(b/139482157): define optional shared attributes |
| case EAP_AT_PERMANENT_ID_REQ: |
| return new AtPermanentIdReq(lengthInBytes, byteBuffer); |
| case EAP_AT_ANY_ID_REQ: |
| return new AtAnyIdReq(lengthInBytes, byteBuffer); |
| case EAP_AT_FULLAUTH_ID_REQ: |
| return new AtFullauthIdReq(lengthInBytes, byteBuffer); |
| case EAP_AT_IDENTITY: |
| return new AtIdentity(lengthInBytes, byteBuffer); |
| case EAP_AT_PADDING: |
| return new AtPadding(lengthInBytes, byteBuffer); |
| case EAP_AT_MAC: |
| return new AtMac(lengthInBytes, byteBuffer); |
| case EAP_AT_COUNTER: |
| return new AtCounter(lengthInBytes, byteBuffer); |
| case EAP_AT_COUNTER_TOO_SMALL: |
| return new AtCounterTooSmall(lengthInBytes, byteBuffer); |
| case EAP_AT_NONCE_S: |
| return new AtNonceS(lengthInBytes, byteBuffer); |
| case EAP_AT_NOTIFICATION: |
| return new AtNotification(lengthInBytes, byteBuffer); |
| case EAP_AT_CLIENT_ERROR_CODE: |
| int errorCode = Short.toUnsignedInt(byteBuffer.getShort()); |
| return new AtClientErrorCode(lengthInBytes, errorCode); |
| default: |
| if (attributeType >= SKIPPABLE_ATTRIBUTE_RANGE_START) { |
| return new EapSimAkaUnsupportedAttribute( |
| attributeType, lengthInBytes, byteBuffer); |
| } |
| |
| throw new EapSimAkaUnsupportedAttributeException( |
| "Unexpected EAP Attribute=" + attributeType); |
| } |
| } |
| |
| /** |
| * This method exists only for testing. |
| * |
| * <p>It follows the attributeFactory.getAttribute(ByteBuffer) pattern used by |
| * EapSimAttributeFactory and EapAkaAttributeFactory. |
| */ |
| @VisibleForTesting |
| 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; |
| return getAttribute(attributeType, lengthInBytes, byteBuffer); |
| } |
| } |