util/DigestUtils.java

   1 /*
   2  * Copyright (C) 2007-2012 Argeo GmbH
   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 package org.argeo.util;
  17
  18 import java.io.File;
  19 import java.io.FileInputStream;
  20 import java.io.IOException;
  21 import java.io.InputStream;
  22 import java.nio.ByteBuffer;
  23 import java.nio.channels.FileChannel;
  24 import java.security.MessageDigest;
  25 import java.security.NoSuchAlgorithmException;
  26
  27 /** Utilities around cryptographic digests */
  28 public class DigestUtils {
  29         private static Boolean debug = true;
  30         // TODO: make it writable
  31         private final static Integer byteBufferCapacity = 100 * 1024;// 100 KB
  32
  33         public static String digest(String algorithm, byte[] bytes) {
  34                 try {
  35                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  36                         digest.update(bytes);
  37                         byte[] checksum = digest.digest();
  38                         String res = encodeHexString(checksum);
  39                         return res;
  40                 } catch (Exception e) {
  41                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  42                 }
  43         }
  44
  45         public static String digest(String algorithm, InputStream in) {
  46                 try {
  47                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  48                         // ReadableByteChannel channel = Channels.newChannel(in);
  49                         // ByteBuffer bb = ByteBuffer.allocateDirect(byteBufferCapacity);
  50                         // while (channel.read(bb) > 0)
  51                         // digest.update(bb);
  52                         byte[] buffer = new byte[byteBufferCapacity];
  53                         int read = 0;
  54                         while ((read = in.read(buffer)) > 0) {
  55                                 digest.update(buffer, 0, read);
  56                         }
  57
  58                         byte[] checksum = digest.digest();
  59                         String res = encodeHexString(checksum);
  60                         return res;
  61                 } catch (Exception e) {
  62                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  63                 } finally {
  64                         StreamUtils.closeQuietly(in);
  65                 }
  66         }
  67
  68         public static String digest(String algorithm, File file) {
  69                 FileInputStream fis = null;
  70                 FileChannel fc = null;
  71                 try {
  72                         fis = new FileInputStream(file);
  73                         fc = fis.getChannel();
  74
  75                         // Get the file's size and then map it into memory
  76                         int sz = (int) fc.size();
  77                         ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);
  78                         return digest(algorithm, bb);
  79                 } catch (IOException e) {
  80                         throw new UtilsException("Cannot digest " + file + " with algorithm " + algorithm, e);
  81                 } finally {
  82                         StreamUtils.closeQuietly(fis);
  83                         if (fc.isOpen())
  84                                 try {
  85                                         fc.close();
  86                                 } catch (IOException e) {
  87                                         // silent
  88                                 }
  89                 }
  90         }
  91
  92         protected static String digest(String algorithm, ByteBuffer bb) {
  93                 long begin = System.currentTimeMillis();
  94                 try {
  95                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  96                         digest.update(bb);
  97                         byte[] checksum = digest.digest();
  98                         String res = encodeHexString(checksum);
  99                         long end = System.currentTimeMillis();
 100                         if (debug)
 101                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 102                         return res;
 103                 } catch (NoSuchAlgorithmException e) {
 104                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
 105                 }
 106         }
 107
 108         public static void main(String[] args) {
 109                 File file;
 110                 if (args.length > 0)
 111                         file = new File(args[0]);
 112                 else {
 113                         System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
 114                                         + "docs/guide/security/CryptoSpec.html#AppA)");
 115                         return;
 116                 }
 117
 118                 if (args.length > 1) {
 119                         String algorithm = args[1];
 120                         System.out.println(digest(algorithm, file));
 121                 } else {
 122                         String algorithm = "MD5";
 123                         System.out.println(algorithm + ": " + digest(algorithm, file));
 124                         algorithm = "SHA";
 125                         System.out.println(algorithm + ": " + digest(algorithm, file));
 126                         algorithm = "SHA-256";
 127                         System.out.println(algorithm + ": " + digest(algorithm, file));
 128                         algorithm = "SHA-512";
 129                         System.out.println(algorithm + ": " + digest(algorithm, file));
 130                 }
 131         }
 132
 133         final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
 134
 135         /**
 136          * From
 137          * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
 138          * -a-hex-string-in-java
 139          */
 140         private static String encodeHexString(byte[] bytes) {
 141                 char[] hexChars = new char[bytes.length * 2];
 142                 for (int j = 0; j < bytes.length; j++) {
 143                         int v = bytes[j] & 0xFF;
 144                         hexChars[j * 2] = hexArray[v >>> 4];
 145                         hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 146                 }
 147                 return new String(hexChars);
 148         }
 149
 150 }