org.argeo.util/src/org/argeo/util/security/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.security;
  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 import org.argeo.util.internal.UtilsException;
  28 import org.argeo.util.internal.StreamUtils;
  29
  30 /** Utilities around cryptographic digests */
  31 public class DigestUtils {
  32         private static Boolean debug = true;
  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 void main(String[] args) {
 112                 File file;
 113                 if (args.length > 0)
 114                         file = new File(args[0]);
 115                 else {
 116                         System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
 117                                         + "docs/guide/security/CryptoSpec.html#AppA)");
 118                         return;
 119                 }
 120
 121                 if (args.length > 1) {
 122                         String algorithm = args[1];
 123                         System.out.println(digest(algorithm, file));
 124                 } else {
 125                         String algorithm = "MD5";
 126                         System.out.println(algorithm + ": " + digest(algorithm, file));
 127                         algorithm = "SHA";
 128                         System.out.println(algorithm + ": " + digest(algorithm, file));
 129                         algorithm = "SHA-256";
 130                         System.out.println(algorithm + ": " + digest(algorithm, file));
 131                         algorithm = "SHA-512";
 132                         System.out.println(algorithm + ": " + digest(algorithm, file));
 133                 }
 134         }
 135
 136         final private static char[] hexArray = "0123456789ABCDEF".toCharArray();
 137
 138         /**
 139          * From
 140          * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
 141          * -a-hex-string-in-java
 142          */
 143         private static String encodeHexString(byte[] bytes) {
 144                 char[] hexChars = new char[bytes.length * 2];
 145                 for (int j = 0; j < bytes.length; j++) {
 146                         int v = bytes[j] & 0xFF;
 147                         hexChars[j * 2] = hexArray[v >>> 4];
 148                         hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 149                 }
 150                 return new String(hexChars);
 151         }
 152
 153 }