DigestUtils.java

   1 package org.argeo.util;
   2
   3 import java.io.File;
   4 import java.io.FileInputStream;
   5 import java.io.IOException;
   6 import java.io.InputStream;
   7 import java.nio.ByteBuffer;
   8 import java.nio.channels.FileChannel;
   9 import java.nio.channels.FileChannel.MapMode;
  10 import java.nio.file.Files;
  11 import java.nio.file.Path;
  12 import java.security.MessageDigest;
  13 import java.security.NoSuchAlgorithmException;
  14
  15 /** Utilities around cryptographic digests */
  16 public class DigestUtils {
  17         public final static String MD5 = "MD5";
  18         public final static String SHA1 = "SHA1";
  19         public final static String SHA256 = "SHA-256";
  20         public final static String SHA512 = "SHA-512";
  21
  22         private static Boolean debug = false;
  23         // TODO: make it configurable
  24         private final static Integer byteBufferCapacity = 100 * 1024;// 100 KB
  25
  26         public static byte[] sha1(byte[] bytes) {
  27                 try {
  28                         MessageDigest digest = MessageDigest.getInstance(SHA1);
  29                         digest.update(bytes);
  30                         byte[] checksum = digest.digest();
  31                         return checksum;
  32                 } catch (NoSuchAlgorithmException e) {
  33                         throw new IllegalArgumentException(e);
  34                 }
  35         }
  36
  37         public static String digest(String algorithm, byte[] bytes) {
  38                 try {
  39                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  40                         digest.update(bytes);
  41                         byte[] checksum = digest.digest();
  42                         String res = encodeHexString(checksum);
  43                         return res;
  44                 } catch (NoSuchAlgorithmException e) {
  45                         throw new IllegalArgumentException("Cannot digest with algorithm " + algorithm, e);
  46                 }
  47         }
  48
  49         public static String digest(String algorithm, InputStream in) {
  50                 try {
  51                         MessageDigest digest = MessageDigest.getInstance(algorithm);
  52                         // ReadableByteChannel channel = Channels.newChannel(in);
  53                         // ByteBuffer bb = ByteBuffer.allocateDirect(byteBufferCapacity);
  54                         // while (channel.read(bb) > 0)
  55                         // digest.update(bb);
  56                         byte[] buffer = new byte[byteBufferCapacity];
  57                         int read = 0;
  58                         while ((read = in.read(buffer)) > 0) {
  59                                 digest.update(buffer, 0, read);
  60                         }
  61
  62                         byte[] checksum = digest.digest();
  63                         String res = encodeHexString(checksum);
  64                         return res;
  65                 } catch (NoSuchAlgorithmException e) {
  66                         throw new IllegalArgumentException("Cannot digest with algorithm " + algorithm, e);
  67                 } catch (IOException e) {
  68                         throw new RuntimeException(e);
  69                 } finally {
  70                         StreamUtils.closeQuietly(in);
  71                 }
  72         }
  73
  74         public static String digest(String algorithm, File file) {
  75                 FileInputStream fis = null;
  76                 FileChannel fc = null;
  77                 try {
  78                         fis = new FileInputStream(file);
  79                         fc = fis.getChannel();
  80
  81                         // Get the file's size and then map it into memory
  82                         int sz = (int) fc.size();
  83                         ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, sz);
  84                         return digest(algorithm, bb);
  85                 } catch (IOException e) {
  86                         throw new IllegalArgumentException("Cannot digest " + file + " with algorithm " + algorithm, e);
  87                 } finally {
  88                         StreamUtils.closeQuietly(fis);
  89                         if (fc.isOpen())
  90                                 try {
  91                                         fc.close();
  92                                 } catch (IOException e) {
  93                                         // silent
  94                                 }
  95                 }
  96         }
  97
  98         protected static String digest(String algorithm, ByteBuffer bb) {
  99                 long begin = System.currentTimeMillis();
 100                 try {
 101                         MessageDigest digest = MessageDigest.getInstance(algorithm);
 102                         digest.update(bb);
 103                         byte[] checksum = digest.digest();
 104                         String res = encodeHexString(checksum);
 105                         long end = System.currentTimeMillis();
 106                         if (debug)
 107                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 108                         return res;
 109                 } catch (NoSuchAlgorithmException e) {
 110                         throw new IllegalArgumentException("Cannot digest with algorithm " + algorithm, e);
 111                 }
 112         }
 113
 114         public static String sha1hex(Path path) {
 115                 return digest(SHA1, path, byteBufferCapacity);
 116         }
 117
 118         public static String digest(String algorithm, Path path, long bufferSize) {
 119                 byte[] digest = digestRaw(algorithm, path, bufferSize);
 120                 return encodeHexString(digest);
 121         }
 122
 123         public static byte[] digestRaw(String algorithm, Path file, long bufferSize) {
 124                 long begin = System.currentTimeMillis();
 125                 try {
 126                         MessageDigest md = MessageDigest.getInstance(algorithm);
 127                         FileChannel fc = FileChannel.open(file);
 128                         long fileSize = Files.size(file);
 129                         if (fileSize <= bufferSize) {
 130                                 ByteBuffer bb = fc.map(MapMode.READ_ONLY, 0, fileSize);
 131                                 md.update(bb);
 132                         } else {
 133                                 long lastCycle = (fileSize / bufferSize) - 1;
 134                                 long position = 0;
 135                                 for (int i = 0; i <= lastCycle; i++) {
 136                                         ByteBuffer bb;
 137                                         if (i != lastCycle) {
 138                                                 bb = fc.map(MapMode.READ_ONLY, position, bufferSize);
 139                                                 position = position + bufferSize;
 140                                         } else {
 141                                                 bb = fc.map(MapMode.READ_ONLY, position, fileSize - position);
 142                                                 position = fileSize;
 143                                         }
 144                                         md.update(bb);
 145                                 }
 146                         }
 147                         long end = System.currentTimeMillis();
 148                         if (debug)
 149                                 System.out.println((end - begin) + " ms / " + ((end - begin) / 1000) + " s");
 150                         return md.digest();
 151                 } catch (NoSuchAlgorithmException e) {
 152                         throw new IllegalArgumentException("Cannot digest " + file + "  with algorithm " + algorithm, e);
 153                 } catch (IOException e) {
 154                         throw new RuntimeException("Cannot digest " + file + "  with algorithm " + algorithm, e);
 155                 }
 156         }
 157
 158         public static void main(String[] args) {
 159                 File file;
 160                 if (args.length > 0)
 161                         file = new File(args[0]);
 162                 else {
 163                         System.err.println("Usage: <file> [<algorithm>]" + " (see http://java.sun.com/j2se/1.5.0/"
 164                                         + "docs/guide/security/CryptoSpec.html#AppA)");
 165                         return;
 166                 }
 167
 168                 if (args.length > 1) {
 169                         String algorithm = args[1];
 170                         System.out.println(digest(algorithm, file));
 171                 } else {
 172                         String algorithm = "MD5";
 173                         System.out.println(algorithm + ": " + digest(algorithm, file));
 174                         algorithm = "SHA";
 175                         System.out.println(algorithm + ": " + digest(algorithm, file));
 176                         System.out.println(algorithm + ": " + sha1hex(file.toPath()));
 177                         algorithm = "SHA-256";
 178                         System.out.println(algorithm + ": " + digest(algorithm, file));
 179                         algorithm = "SHA-512";
 180                         System.out.println(algorithm + ": " + digest(algorithm, file));
 181                 }
 182         }
 183
 184         final private static char[] hexArray = "0123456789abcdef".toCharArray();
 185
 186         /**
 187          * From
 188          * http://stackoverflow.com/questions/9655181/how-to-convert-a-byte-array-to
 189          * -a-hex-string-in-java
 190          */
 191         public static String encodeHexString(byte[] bytes) {
 192                 char[] hexChars = new char[bytes.length * 2];
 193                 for (int j = 0; j < bytes.length; j++) {
 194                         int v = bytes[j] & 0xFF;
 195                         hexChars[j * 2] = hexArray[v >>> 4];
 196                         hexChars[j * 2 + 1] = hexArray[v & 0x0F];
 197                 }
 198                 return new String(hexChars);
 199         }
 200
 201 }