annotate src/com/tmate/hgkit/ll/DigestHelper.java @ 13:df8c67f3006a

Basic manifest parsing to analyze what's in there
author Artem Tikhomirov <tikhomirov.artem@gmail.com>
date Sun, 26 Dec 2010 03:21:17 +0100
parents d6d2a630f4a6
children 571e1b2cc3f7
rev   line source
9
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
1 /**
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
2 * Copyright (c) 2010 Artem Tikhomirov
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
3 */
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
4 package com.tmate.hgkit.ll;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
5
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
6 import java.io.IOException;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
7 import java.io.InputStream;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
8 import java.security.MessageDigest;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
9 import java.security.NoSuchAlgorithmException;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
10
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
11 /**
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
12 *
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
13 * @author artem
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
14 */
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
15 public class DigestHelper {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
16 private MessageDigest sha1;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
17
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
18 public DigestHelper() {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
19 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
20
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
21 private MessageDigest getSHA1() {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
22 if (sha1 == null) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
23 try {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
24 sha1 = MessageDigest.getInstance("SHA-1");
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
25 } catch (NoSuchAlgorithmException ex) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
26 // could hardly happen, JDK from Sun always has sha1.
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
27 ex.printStackTrace(); // FIXME log error
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
28 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
29 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
30 return sha1;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
31 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
32
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
33 // XXX perhaps, digest functions should throw an exception, as it's caller responsibility to deal with eof, etc
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
34 public String sha1(byte[] data) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
35 MessageDigest alg = getSHA1();
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
36 byte[] digest = alg.digest(data);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
37 assert digest.length == 20;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
38 return toHexString(digest, 0, 20);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
39 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
40
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
41 public byte[] sha1(InputStream is /*ByteBuffer*/) throws IOException {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
42 MessageDigest alg = getSHA1();
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
43 byte[] buf = new byte[1024];
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
44 int c;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
45 while ((c = is.read(buf)) != -1) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
46 alg.update(buf, 0, c);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
47 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
48 byte[] digest = alg.digest();
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
49 return digest;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
50 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
51
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
52 public String toHexString(byte[] data, final int offset, final int count) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
53 char[] result = new char[count << 1];
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
54 final String hexDigits = "0123456789abcdef";
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
55 final int end = offset+count;
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
56 for (int i = offset, j = 0; i < end; i++) {
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
57 result[j++] = hexDigits.charAt((data[i] >>> 4) & 0x0F);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
58 result[j++] = hexDigits.charAt(data[i] & 0x0F);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
59 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
60 return new String(result);
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
61 }
d6d2a630f4a6 Access to underlaying file data wrapped into own Access object, implemented with FileChannel and ByteBuffer
Artem Tikhomirov <tikhomirov.artem@gmail.com>
parents:
diff changeset
62 }