1 /*
2  * Copyright (C) 2008 The Android Open Source Project
3  *
4  * Licensed under the Eclipse Public License, Version 1.0 (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.eclipse.org/org/documents/epl-v10.php
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.ide.eclipse.adt.internal.utils;
18 
19 import java.util.Locale;
20 import java.security.MessageDigest;
21 import java.security.NoSuchAlgorithmException;
22 import java.security.cert.Certificate;
23 import java.security.cert.CertificateEncodingException;
24 
25 public class FingerprintUtils {
26 
27     /**
28      * Returns the {@link Certificate} fingerprint as returned by <code>keytool</code>.
29      *
30      * @param certificate
31      * @param hashAlgorithm
32      */
getFingerprint(Certificate cert, String hashAlgorithm)33     public static String getFingerprint(Certificate cert, String hashAlgorithm) {
34         if (cert == null) {
35             return null;
36         }
37         try {
38             MessageDigest digest = MessageDigest.getInstance(hashAlgorithm);
39             return toHexadecimalString(digest.digest(cert.getEncoded()));
40         } catch(NoSuchAlgorithmException e) {
41             // ignore
42         } catch(CertificateEncodingException e) {
43             // ignore
44         }
45         return null;
46     }
47 
toHexadecimalString(byte[] value)48     private static String toHexadecimalString(byte[] value) {
49         StringBuffer sb = new StringBuffer();
50         int len = value.length;
51         for (int i = 0; i < len; i++) {
52             int num = ((int) value[i]) & 0xff;
53             if (num < 0x10) {
54                 sb.append('0');
55             }
56             sb.append(Integer.toHexString(num));
57             if (i < len - 1) {
58                 sb.append(':');
59             }
60         }
61         return sb.toString().toUpperCase(Locale.US);
62     }
63 }