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.nio.channels.FileChannel.MapMode;
  25 import java.nio.file.Files;
  26 import java.nio.file.Path;
  27 import java.security.MessageDigest;
  28 import java.security.NoSuchAlgorithmException;
  29
  30 /** Utilities around cryptographic digests */
  31 public class DigestUtils {
  32         private static Boolean debug = false;
  33         // TODO: make it writable
  34         private final static Integer byteBufferCapacity = 100 * 1024;// 100 KB
  35
  36         public static String digest(String algorithm, byte[] bytes) {
  37                 try {
  38                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  39                         digest.update(bytes);
  40                         byte[] checksum = digest.digest();
  41                         String res = encodeHexString(checksum);
  42                         return res;
  43                 } catch (Exception e) {
  44                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  45                 }
  46         }
  47
  48         public static String digest(String algorithm, InputStream in) {
  49                 try {
  50                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  51                         // ReadableByteChannel channel = Channels.newChannel(in);
  52                         // ByteBuffer bb = ByteBuffer.allocateDirect(byteBufferCapacity);
  53                         // while (channel.read(bb) > 0)
  54                         // digest.update(bb);
  55                         byte[] buffer = new byte[byteBufferCapacity];
  56                         int read = 0;
  57                         while ((read = in.read(buffer)) > 0) {
  58                                 digest.update(buffer, 0, read);
  59                         }
  60
  61                         byte[] checksum = digest.digest();
  62                         String res = encodeHexString(checksum);
  63                         return res;
  64                 } catch (Exception e) {
  65                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  66                 } finally {
  67                         StreamUtils.closeQuietly(in);
  68                 }
  69         }
  70
  71         public static String digest(String algorithm, File file) {
  72                 FileInputStream fis = null;
  73                 FileChannel fc = null;
  74                 try {
  75                         fis = new FileInputStream(file);
  76                         fc = fis.getChannel();
  77
  78                         // Get the file's size and then map it into memory
  79                         int sz = (int) fc.size();
  80                         ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);
  81                         return digest(algorithm, bb);
  82                 } catch (IOException e) {
  83                         throw new UtilsException("Cannot digest " + file + " with algorithm " + algorithm, e);
  84                 } finally {
  85                         StreamUtils.closeQuietly(fis);
  86                         if (fc.isOpen())
  87                                 try {
  88                                         fc.close();
  89                                 } catch (IOException e) {
  90                                         // silent
  91                                 }
  92                 }
  93         }
  94
  95         protected static String digest(String algorithm, ByteBuffer bb) {
  96                 long begin = System.currentTimeMillis();
  97                 try {
  98                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  99                         digest.update(bb);
 100                         byte[] checksum = digest.digest();
 101                         String res = encodeHexString(checksum);
 102                         long end = System.currentTimeMillis();
 103                         if (debug)
 104                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 105                         return res;
 106                 } catch (NoSuchAlgorithmException e) {
 107                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
 108                 }
 109         }
 110
 111         public static byte[] digestRaw(String algorithm, Path file, long bufferSize) {
 112                 long begin = System.currentTimeMillis();
 113                 try {
 114                         MessageDigest md = MessageDigest.getInstance(algorithm);
 115                         FileChannel fc = FileChannel.open(file);
 116                         long fileSize = Files.size(file);
 117                         if (fileSize <= bufferSize) {
 118                                 ByteBuffer bb = fc.map(MapMode.READ_ONLY, 0, fileSize);
 119                                 md.update(bb);
 120                         } else {
 121                                 long lastCycle = (fileSize / bufferSize) - 1;
 122                                 long position = 0;
 123                                 for (int i = 0; i <= lastCycle; i++) {
 124                                         ByteBuffer bb;
 125                                         if (i != lastCycle) {
 126                                                 bb = fc.map(MapMode.READ_ONLY, position, bufferSize);
 127                                                 position = position + bufferSize;
 128                                         } else {
 129                                                 bb = fc.map(MapMode.READ_ONLY, position, fileSize - bufferSize);
 130                                                 position = fileSize;
 131                                         }
 132                                         md.update(bb);
 133                                 }
 134                         }
 135                         long end = System.currentTimeMillis();
 136                         if (debug)
 137                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 138                         return md.digest();
 139                 } catch (Exception e) {
 140                         throw new UtilsException("Cannot digest " + file + "  with algorithm " + algorithm, e);
 141                 }
 142         }
 143
 144         public static void main(String[] args) {
 145                 File file;
 146                 if (args.length > 0)
 147                         file = new File(args[0]);
 148                 else {
 149                         System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
 150                                         + "docs/guide/security/CryptoSpec.html#AppA)");
 151                         return;
 152                 }
 153
 154                 if (args.length > 1) {
 155                         String algorithm = args[1];
 156                         System.out.println(digest(algorithm, file));
 157                 } else {
 158                         String algorithm = "MD5";
 159                         System.out.println(algorithm + ": " + digest(algorithm, file));
 160                         algorithm = "SHA";
 161                         System.out.println(algorithm + ": " + digest(algorithm, file));
 162                         algorithm = "SHA-256";
 163                         System.out.println(algorithm + ": " + digest(algorithm, file));
 164                         algorithm = "SHA-512";
 165                         System.out.println(algorithm + ": " + digest(algorithm, file));
 166                 }
 167         }
 168
 169         final private static char[] hexArray = "0123456789abcdef".toCharArray();
 170
 171         /**
 172          * From
 173          * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
 174          * -a-hex-string-in-java
 175          */
 176         public static String encodeHexString(byte[] bytes) {
 177                 char[] hexChars = new char[bytes.length * 2];
 178                 for (int j = 0; j < bytes.length; j++) {
 179                         int v = bytes[j] & 0xFF;
 180                         hexChars[j * 2] = hexArray[v >>> 4];
 181                         hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 182                 }
 183                 return new String(hexChars);
 184         }
 185
 186 }