1 /*
2  * Copyright (C) 2018 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 package com.android.server.wifi.hotspot2;
18 
19 import android.util.Log;
20 
21 import java.io.File;
22 import java.io.FileInputStream;
23 import java.io.IOException;
24 import java.security.cert.Certificate;
25 import java.security.cert.CertificateException;
26 import java.security.cert.CertificateFactory;
27 import java.security.cert.X509Certificate;
28 import java.util.HashSet;
29 import java.util.Set;
30 
31 /**
32  * Provides static method to build certificate set from cert files
33  */
34 public class WfaCertBuilder {
35 
36     private static final String TAG = "PasspointWfaCertBuilder";
37 
38     /**
39      * Returns a set of X509 Certificates from a set of WFA cert files
40      * @param directory the location where the cert files are stored
41      * @return Set<X509Certificate> certificates obtained from the files
42      */
loadCertsFromDisk(String directory)43     public static Set<X509Certificate> loadCertsFromDisk(String directory) {
44         Set<X509Certificate> certs = new HashSet<>();
45         try {
46             File certDir = new File(directory);
47             File[] certFiles = certDir.listFiles();
48             if (certFiles == null || certFiles.length <= 0) {
49                 return certs;
50             }
51             CertificateFactory certFactory = CertificateFactory.getInstance("X.509");
52             for (File certFile : certFiles) {
53                 FileInputStream fis = new FileInputStream(certFile);
54                 Certificate cert = certFactory.generateCertificate(fis);
55                 if (cert instanceof X509Certificate) {
56                     certs.add((X509Certificate) cert);
57                 }
58                 fis.close();
59             }
60         } catch (CertificateException | IOException | SecurityException e) {
61             Log.e(TAG, "Unable to read cert " + e.getMessage());
62         }
63         return certs;
64     }
65 }
66