1/*
2 * Copyright (C) 2015 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package android.security.keymaster;
18
19import android.os.Parcel;
20import android.os.Parcelable;
21import android.os.ParcelFormatException;
22
23/**
24 * Base class for the Java side of a Keymaster tagged argument.
25 * <p>
26 * Serialization code for this and subclasses must be kept in sync with system/security/keystore
27 * and with hardware/libhardware/include/hardware/keymaster_defs.h
28 * @hide
29 */
30abstract class KeymasterArgument implements Parcelable {
31    public final int tag;
32
33    public static final Parcelable.Creator<KeymasterArgument> CREATOR = new
34            Parcelable.Creator<KeymasterArgument>() {
35                @Override
36                public KeymasterArgument createFromParcel(Parcel in) {
37                    final int pos = in.dataPosition();
38                    final int tag = in.readInt();
39                    switch (KeymasterDefs.getTagType(tag)) {
40                        case KeymasterDefs.KM_ENUM:
41                        case KeymasterDefs.KM_ENUM_REP:
42                        case KeymasterDefs.KM_UINT:
43                        case KeymasterDefs.KM_UINT_REP:
44                            return new KeymasterIntArgument(tag, in);
45                        case KeymasterDefs.KM_ULONG:
46                        case KeymasterDefs.KM_ULONG_REP:
47                            return new KeymasterLongArgument(tag, in);
48                        case KeymasterDefs.KM_DATE:
49                            return new KeymasterDateArgument(tag, in);
50                        case KeymasterDefs.KM_BYTES:
51                        case KeymasterDefs.KM_BIGNUM:
52                            return new KeymasterBlobArgument(tag, in);
53                        case KeymasterDefs.KM_BOOL:
54                            return new KeymasterBooleanArgument(tag, in);
55                        default:
56                            throw new ParcelFormatException("Bad tag: " + tag + " at " + pos);
57                    }
58                }
59
60                @Override
61                public KeymasterArgument[] newArray(int size) {
62                    return new KeymasterArgument[size];
63                }
64            };
65
66    protected KeymasterArgument(int tag) {
67        this.tag = tag;
68    }
69
70    /**
71     * Writes the value of this argument, if any, to the provided parcel.
72     */
73    public abstract void writeValue(Parcel out);
74
75    @Override
76    public int describeContents() {
77        return 0;
78    }
79
80    @Override
81    public void writeToParcel(Parcel out, int flags) {
82        out.writeInt(tag);
83        writeValue(out);
84    }
85}
86