1 /*
2  * Copyright (C) 2017 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 /*
17  * Copyright (c) 2015-2017, The Linux Foundation.
18  */
19 
20 /*
21  * Copyright 2010 Giesecke & Devrient GmbH.
22  *
23  * Licensed under the Apache License, Version 2.0 (the "License");
24  * you may not use this file except in compliance with the License.
25  * You may obtain a copy of the License at
26  *
27  *      http://www.apache.org/licenses/LICENSE-2.0
28  *
29  * Unless required by applicable law or agreed to in writing, software
30  * distributed under the License is distributed on an "AS IS" BASIS,
31  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
32  * See the License for the specific language governing permissions and
33  * limitations under the License.
34  */
35 
36 package com.android.se.security.ara;
37 
38 import com.android.se.Channel;
39 import com.android.se.security.CommandApdu;
40 import com.android.se.security.ResponseApdu;
41 import com.android.se.security.gpac.BerTlv;
42 import com.android.se.security.gpac.ParserException;
43 import com.android.se.security.gpac.Response_DO_Factory;
44 import com.android.se.security.gpac.Response_RefreshTag_DO;
45 
46 import java.io.ByteArrayOutputStream;
47 import java.io.IOException;
48 import java.security.AccessControlException;
49 
50 /** Reads the ARA Rules from the Secure Element */
51 public class AccessRuleApplet {
52     private static final int MAX_LEN = 0x00;
53     private static final CommandApdu GET_ALL_CMD = new CommandApdu(0x80, 0xCA, 0xFF, 0x40, MAX_LEN);
54     // MAX_LEN should be adapted by OEM, this is a defensive value since some devices/modems have
55     // problems with Le=0x00 or 0xFF.
56     private static final CommandApdu GET_NEXT_CMD = new CommandApdu(0x80, 0xCA, 0xFF, 0x60,
57             MAX_LEN);
58     private static final CommandApdu GET_REFRESH_TAG = new CommandApdu(0x80, 0xCA, 0xDF, 0x20,
59             MAX_LEN);
60     private final String mTag = "SecureElement-AccessRuleApplet";
61     private Channel mChannel = null;
62 
AccessRuleApplet(Channel channel)63     public AccessRuleApplet(Channel channel) {
64         mChannel = channel;
65     }
66 
67     /** Reads all the access rules from the secure element */
readAllAccessRules()68     public byte[] readAllAccessRules() throws AccessControlException, IOException {
69         ByteArrayOutputStream stream = new ByteArrayOutputStream();
70         int overallLen = 0;
71 
72         // send GET DATA (specific)
73         CommandApdu apdu = (CommandApdu) GET_ALL_CMD.clone();
74         ResponseApdu response = send(apdu);
75 
76         // OK
77         if (response.isStatus(0x9000)) {
78             // check if more data has to be fetched
79             BerTlv tempTlv = null;
80             try {
81                 tempTlv = BerTlv.decode(response.getData(), 0, false);
82             } catch (ParserException e) {
83                 throw new AccessControlException(
84                         "GET DATA (all) not successfull. Tlv encoding wrong.");
85             }
86 
87             // the first data block contain the length of the TLV + Tag bytes + length bytes.
88             overallLen = tempTlv.getValueLength() + tempTlv.getValueIndex();
89 
90             try {
91                 stream.write(response.getData());
92             } catch (IOException e) {
93                 throw new AccessControlException("GET DATA (all) IO problem. " + e.getMessage());
94             }
95 
96             int le;
97             // send subsequent GET DATA (next) commands
98             while (stream.size() < overallLen) {
99                 le = overallLen - stream.size();
100 
101                 if (le > MAX_LEN) {
102                     le = MAX_LEN;
103                 }
104                 // send GET DATA (next)
105                 apdu = (CommandApdu) GET_NEXT_CMD.clone();
106                 apdu.setLe(le);
107 
108                 response = send(apdu);
109                 // OK
110                 if (response.isStatus(0x9000)) {
111                     try {
112                         stream.write(response.getData());
113                     } catch (IOException e) {
114                         throw new AccessControlException("GET DATA (next) IO problem. "
115                                 + e.getMessage());
116                     }
117                 } else {
118                     throw new AccessControlException("GET DATA (next) not successfull, SW1SW2="
119                             + response.getSW1SW2());
120                 }
121             }
122             return stream.toByteArray();
123             // referenced data not found
124         } else if (response.isStatus(0x6A88)) {
125             return null;
126         } else {
127             throw new AccessControlException("GET DATA (all) not successfull. SW1SW2="
128                     + response.getSW1SW2());
129         }
130     }
131 
132     /** Fetches the Refresh Tag from the Secure Element */
readRefreshTag()133     public byte[] readRefreshTag() throws AccessControlException, IOException {
134         CommandApdu apdu = (CommandApdu) GET_REFRESH_TAG.clone();
135         ResponseApdu response = send(apdu);
136         // OK
137         if (response.isStatus(0x9000)) {
138             // check if more data has to be fetched
139             BerTlv tempTlv = null;
140             Response_RefreshTag_DO refreshDo;
141             try {
142                 tempTlv = Response_DO_Factory.createDO(response.getData());
143                 if (tempTlv instanceof Response_RefreshTag_DO) {
144                     refreshDo = (Response_RefreshTag_DO) tempTlv;
145                     return refreshDo.getRefreshTagArray();
146                 } else {
147                     throw new AccessControlException("GET REFRESH TAG returned invalid Tlv.");
148                 }
149             } catch (ParserException e) {
150                 throw new AccessControlException(
151                         "GET REFRESH TAG not successfull. Tlv encoding wrong.");
152             }
153         }
154         throw new AccessControlException("GET REFRESH TAG not successfull.");
155     }
156 
send(CommandApdu cmdApdu)157     private ResponseApdu send(CommandApdu cmdApdu) throws IOException {
158         byte[] response = mChannel.transmit(cmdApdu.toBytes());
159         return new ResponseApdu(response);
160     }
161 }
162