1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
|
/*
* 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.ike.eap.message.simaka;
import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_NONCE_MT;
import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_RAND;
import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_SELECTED_VERSION;
import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.EAP_AT_VERSION_LIST;
import static com.android.ike.eap.message.simaka.EapSimAkaAttribute.LENGTH_SCALING;
import com.android.ike.eap.exceptions.simaka.EapSimAkaInvalidAttributeException;
import com.android.ike.eap.exceptions.simaka.EapSimAkaUnsupportedAttributeException;
import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtNonceMt;
import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtRandSim;
import com.android.ike.eap.message.simaka.EapSimAkaAttribute.AtSelectedVersion;
import com.android.ike.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);
}
}
}
|
