Utils.java revision cee5bfdf119104b8ebce56d54dfcdcca1f537075 
1/*
2 * Copyright (C) 2014 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 com.android.verity;
18
19import java.lang.reflect.Constructor;
20import java.io.File;
21import java.io.FileInputStream;
22import java.io.FileOutputStream;
23import java.io.IOException;
24import java.security.PrivateKey;
25import java.security.PublicKey;
26import java.security.KeyFactory;
27import java.security.Provider;
28import java.security.Security;
29import java.security.Signature;
30import java.security.spec.X509EncodedKeySpec;
31import java.security.spec.PKCS8EncodedKeySpec;
32
33import org.bouncycastle.util.encoders.Base64;
34
35public class Utils {
36
37    private static void loadProviderIfNecessary(String providerClassName) {
38        if (providerClassName == null) {
39            return;
40        }
41
42        final Class<?> klass;
43        try {
44            final ClassLoader sysLoader = ClassLoader.getSystemClassLoader();
45            if (sysLoader != null) {
46                klass = sysLoader.loadClass(providerClassName);
47            } else {
48                klass = Class.forName(providerClassName);
49            }
50        } catch (ClassNotFoundException e) {
51            e.printStackTrace();
52            System.exit(1);
53            return;
54        }
55
56        Constructor<?> constructor = null;
57        for (Constructor<?> c : klass.getConstructors()) {
58            if (c.getParameterTypes().length == 0) {
59                constructor = c;
60                break;
61            }
62        }
63        if (constructor == null) {
64            System.err.println("No zero-arg constructor found for " + providerClassName);
65            System.exit(1);
66            return;
67        }
68
69        final Object o;
70        try {
71            o = constructor.newInstance();
72        } catch (Exception e) {
73            e.printStackTrace();
74            System.exit(1);
75            return;
76        }
77        if (!(o instanceof Provider)) {
78            System.err.println("Not a Provider class: " + providerClassName);
79            System.exit(1);
80        }
81
82        Security.insertProviderAt((Provider) o, 1);
83    }
84
85    static byte[] pemToDer(String pem) throws Exception {
86        pem = pem.replaceAll("^-.*", "");
87        String base64_der = pem.replaceAll("-.*$", "");
88        return Base64.decode(base64_der);
89    }
90
91    static PrivateKey loadDERPrivateKey(byte[] der) throws Exception {
92        PKCS8EncodedKeySpec keySpec = new PKCS8EncodedKeySpec(der);
93        KeyFactory keyFactory = KeyFactory.getInstance("RSA");
94        return (PrivateKey) keyFactory.generatePrivate(keySpec);
95    }
96
97    static PrivateKey loadPEMPrivateKey(byte[] pem) throws Exception {
98        byte[] der = pemToDer(new String(pem));
99        return loadDERPrivateKey(der);
100    }
101
102    static PrivateKey loadPEMPrivateKeyFromFile(String keyFname) throws Exception {
103        return loadPEMPrivateKey(read(keyFname));
104    }
105
106    static PrivateKey loadDERPrivateKeyFromFile(String keyFname) throws Exception {
107        return loadDERPrivateKey(read(keyFname));
108    }
109
110    static PublicKey loadDERPublicKey(byte[] der) throws Exception {
111        X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(der);
112        KeyFactory factory = KeyFactory.getInstance("RSA");
113        return factory.generatePublic(publicKeySpec);
114    }
115
116    static PublicKey loadPEMPublicKey(byte[] pem) throws Exception {
117        byte[] der = pemToDer(new String(pem));
118        X509EncodedKeySpec publicKeySpec = new X509EncodedKeySpec(der);
119        KeyFactory factory = KeyFactory.getInstance("RSA");
120        return factory.generatePublic(publicKeySpec);
121    }
122
123    static PublicKey loadPEMPublicKeyFromFile(String keyFname) throws Exception {
124        return loadPEMPublicKey(read(keyFname));
125    }
126
127    static PublicKey loadDERPublicKeyFromFile(String keyFname) throws Exception {
128        return loadDERPublicKey(read(keyFname));
129    }
130
131    static byte[] sign(PrivateKey privateKey, byte[] input) throws Exception {
132        Signature signer = Signature.getInstance("SHA1withRSA");
133        signer.initSign(privateKey);
134        signer.update(input);
135        return signer.sign();
136    }
137
138    static byte[] read(String fname) throws Exception {
139        long offset = 0;
140        File f = new File(fname);
141        long length = f.length();
142        byte[] image = new byte[(int)length];
143        FileInputStream fis = new FileInputStream(f);
144        while (offset < length) {
145            offset += fis.read(image, (int)offset, (int)(length - offset));
146        }
147        fis.close();
148        return image;
149    }
150
151    static void write(byte[] data, String fname) throws Exception{
152        FileOutputStream out = new FileOutputStream(fname);
153        out.write(data);
154        out.close();
155    }
156}