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