org.argeo.util/src/org/argeo/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         public final static String SHA1 = "SHA1";
  33
  34         private static Boolean debug = false;
  35         // TODO: make it writable
  36         private final static Integer byteBufferCapacity = 100 * 1024;// 100 KB
  37
  38         public static byte[] sha1(byte[] bytes) {
  39                 try {
  40                         MessageDigest digest = MessageDigest.getInstance(SHA1);
  41                         digest.update(bytes);
  42                         byte[] checksum = digest.digest();
  43                         return checksum;
  44                 } catch (Exception e) {
  45                         throw new UtilsException("Cannot SHA1 digest", e);
  46                 }
  47         }
  48
  49         public static String digest(String algorithm, byte[] bytes) {
  50                 try {
  51                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  52                         digest.update(bytes);
  53                         byte[] checksum = digest.digest();
  54                         String res = encodeHexString(checksum);
  55                         return res;
  56                 } catch (Exception e) {
  57                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  58                 }
  59         }
  60
  61         public static String digest(String algorithm, InputStream in) {
  62                 try {
  63                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  64                         // ReadableByteChannel channel = Channels.newChannel(in);
  65                         // ByteBuffer bb = ByteBuffer.allocateDirect(byteBufferCapacity);
  66                         // while (channel.read(bb) > 0)
  67                         // digest.update(bb);
  68                         byte[] buffer = new byte[byteBufferCapacity];
  69                         int read = 0;
  70                         while ((read = in.read(buffer)) > 0) {
  71                                 digest.update(buffer, 0, read);
  72                         }
  73
  74                         byte[] checksum = digest.digest();
  75                         String res = encodeHexString(checksum);
  76                         return res;
  77                 } catch (Exception e) {
  78                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
  79                 } finally {
  80                         StreamUtils.closeQuietly(in);
  81                 }
  82         }
  83
  84         public static String digest(String algorithm, File file) {
  85                 FileInputStream fis = null;
  86                 FileChannel fc = null;
  87                 try {
  88                         fis = new FileInputStream(file);
  89                         fc = fis.getChannel();
  90
  91                         // Get the file's size and then map it into memory
  92                         int sz = (int) fc.size();
  93                         ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);
  94                         return digest(algorithm, bb);
  95                 } catch (IOException e) {
  96                         throw new UtilsException("Cannot digest " + file + " with algorithm " + algorithm, e);
  97                 } finally {
  98                         StreamUtils.closeQuietly(fis);
  99                         if (fc.isOpen())
 100                                 try {
 101                                         fc.close();
 102                                 } catch (IOException e) {
 103                                         // silent
 104                                 }
 105                 }
 106         }
 107
 108         protected static String digest(String algorithm, ByteBuffer bb) {
 109                 long begin = System.currentTimeMillis();
 110                 try {
 111                         MessageDigest digest = MessageDigest.getInstance(algorithm);
 112                         digest.update(bb);
 113                         byte[] checksum = digest.digest();
 114                         String res = encodeHexString(checksum);
 115                         long end = System.currentTimeMillis();
 116                         if (debug)
 117                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 118                         return res;
 119                 } catch (NoSuchAlgorithmException e) {
 120                         throw new UtilsException("Cannot digest with algorithm " + algorithm, e);
 121                 }
 122         }
 123
 124         public static String sha1hex(Path path) {
 125                 return digest(SHA1, path, byteBufferCapacity);
 126         }
 127
 128         public static String digest(String algorithm, Path path, long bufferSize) {
 129                 byte[] digest = digestRaw(algorithm, path, bufferSize);
 130                 return encodeHexString(digest);
 131         }
 132
 133         public static byte[] digestRaw(String algorithm, Path file, long bufferSize) {
 134                 long begin = System.currentTimeMillis();
 135                 try {
 136                         MessageDigest md = MessageDigest.getInstance(algorithm);
 137                         FileChannel fc = FileChannel.open(file);
 138                         long fileSize = Files.size(file);
 139                         if (fileSize <= bufferSize) {
 140                                 ByteBuffer bb = fc.map(MapMode.READ_ONLY, 0, fileSize);
 141                                 md.update(bb);
 142                         } else {
 143                                 long lastCycle = (fileSize / bufferSize) - 1;
 144                                 long position = 0;
 145                                 for (int i = 0; i <= lastCycle; i++) {
 146                                         ByteBuffer bb;
 147                                         if (i != lastCycle) {
 148                                                 bb = fc.map(MapMode.READ_ONLY, position, bufferSize);
 149                                                 position = position + bufferSize;
 150                                         } else {
 151                                                 bb = fc.map(MapMode.READ_ONLY, position, fileSize - position);
 152                                                 position = fileSize;
 153                                         }
 154                                         md.update(bb);
 155                                 }
 156                         }
 157                         long end = System.currentTimeMillis();
 158                         if (debug)
 159                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 160                         return md.digest();
 161                 } catch (Exception e) {
 162                         throw new UtilsException("Cannot digest " + file + "  with algorithm " + algorithm, e);
 163                 }
 164         }
 165
 166         public static void main(String[] args) {
 167                 File file;
 168                 if (args.length > 0)
 169                         file = new File(args[0]);
 170                 else {
 171                         System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
 172                                         + "docs/guide/security/CryptoSpec.html#AppA)");
 173                         return;
 174                 }
 175
 176                 if (args.length > 1) {
 177                         String algorithm = args[1];
 178                         System.out.println(digest(algorithm, file));
 179                 } else {
 180                         String algorithm = "MD5";
 181                         System.out.println(algorithm + ": " + digest(algorithm, file));
 182                         algorithm = "SHA";
 183                         System.out.println(algorithm + ": " + digest(algorithm, file));
 184                         System.out.println(algorithm + ": " + sha1hex(file.toPath()));
 185                         algorithm = "SHA-256";
 186                         System.out.println(algorithm + ": " + digest(algorithm, file));
 187                         algorithm = "SHA-512";
 188                         System.out.println(algorithm + ": " + digest(algorithm, file));
 189                 }
 190         }
 191
 192         final private static char[] hexArray = "0123456789abcdef".toCharArray();
 193
 194         /**
 195          * From
 196          * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
 197          * -a-hex-string-in-java
 198          */
 199         public static String encodeHexString(byte[] bytes) {
 200                 char[] hexChars = new char[bytes.length * 2];
 201                 for (int j = 0; j < bytes.length; j++) {
 202                         int v = bytes[j] & 0xFF;
 203                         hexChars[j * 2] = hexArray[v >>> 4];
 204                         hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 205                 }
 206                 return new String(hexChars);
 207         }
 208
 209 }