1 /*
2  * Copyright (C) 2009 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.certinstaller;
18 
19 import android.util.Log;
20 
21 import java.io.ByteArrayInputStream;
22 import java.io.ByteArrayOutputStream;
23 import java.io.File;
24 import java.io.FileInputStream;
25 import java.io.ObjectInputStream;
26 import java.io.ObjectOutputStream;
27 import java.security.MessageDigest;
28 import java.security.NoSuchAlgorithmException;
29 
30 class Util {
31     private static final String TAG = "certinstaller.Util";
32 
toBytes(Object object)33     static byte[] toBytes(Object object) {
34         ByteArrayOutputStream baos = new ByteArrayOutputStream();
35         try {
36             ObjectOutputStream os = new ObjectOutputStream(baos);
37             os.writeObject(object);
38             os.close();
39         } catch (Exception e) {
40             Log.w(TAG, "toBytes(): " + e + ": " + object);
41         }
42         return baos.toByteArray();
43     }
44 
fromBytes(byte[] bytes)45     static <T> T fromBytes(byte[] bytes) {
46         if (bytes == null) return null;
47         try {
48             ObjectInputStream is =
49                     new ObjectInputStream(new ByteArrayInputStream(bytes));
50             return (T) is.readObject();
51         } catch (Exception e) {
52             Log.w(TAG, "fromBytes(): " + e);
53             return null;
54         }
55     }
56 
toMd5(byte[] bytes)57     static String toMd5(byte[] bytes) {
58         try {
59             MessageDigest algorithm = MessageDigest.getInstance("MD5");
60             algorithm.reset();
61             algorithm.update(bytes);
62             return toHexString(algorithm.digest(), "");
63         } catch(NoSuchAlgorithmException e){
64             // should not occur
65             Log.w(TAG, "toMd5(): " + e);
66             throw new RuntimeException(e);
67         }
68     }
69 
toHexString(byte[] bytes, String separator)70     private static String toHexString(byte[] bytes, String separator) {
71         StringBuilder hexString = new StringBuilder();
72         for (byte b : bytes) {
73             hexString.append(Integer.toHexString(0xFF & b)).append(separator);
74         }
75         return hexString.toString();
76     }
77 
readFile(File file)78     static byte[] readFile(File file) {
79         try {
80             byte[] data = new byte[(int) file.length()];
81             FileInputStream fis = new FileInputStream(file);
82             fis.read(data);
83             fis.close();
84             return data;
85         } catch (Exception e) {
86             Log.w(TAG, "cert file read error: " + e);
87             return null;
88         }
89     }
90 
deleteFile(File file)91     static boolean deleteFile(File file) {
92         if ((file != null) && !file.delete()) {
93             Log.w(TAG, "cannot delete cert: " + file);
94             return false;
95         } else {
96             return true;
97         }
98     }
99 
Util()100     private Util() {
101     }
102 }
103