package com.twmacinta.util;
import java.io.*;
/**
* MD5InputStream, a subclass of FilterInputStream implementing MD5
* functionality on a stream.
* <p>
* Originally written by Santeri Paavolainen, Helsinki Finland 1996 <br>
* (c) Santeri Paavolainen, Helsinki Finland 1996 <br>
* Some changes Copyright (c) 2002 Timothy W Macinta <br>
* <p>
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* <p>
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
* <p>
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
* <p>
* See http://www.twmacinta.com/myjava/fast_md5.php for more information
* on this file.
* <p>
* Please note: I (Timothy Macinta) have put this code in the
* com.twmacinta.util package only because it came without a package. I
* was not the the original author of the code, although I did
* optimize it (substantially) and fix some bugs.
*
* @author Santeri Paavolainen <santtu@cs.hut.fi>
* @author Timothy W Macinta (twm@alum.mit.edu) (added main() method)
**/
public class MD5InputStream extends FilterInputStream {
/**
* MD5 context
*/
private MD5 md5;
/**
* Creates a MD5InputStream
* @param in The input stream
*/
public MD5InputStream (InputStream in) {
super(in);
md5 = new MD5();
}
/**
* Read a byte of data.
* @see java.io.FilterInputStream
*/
public int read() throws IOException {
int c = in.read();
if (c == -1)
return -1;
if ((c & ~0xff) != 0) {
System.out.println("MD5InputStream.read() got character with (c & ~0xff) != 0)!");
} else {
md5.Update(c);
}
return c;
}
/**
* Reads into an array of bytes.
*
* @see java.io.FilterInputStream
*/
public int read (byte bytes[], int offset, int length) throws IOException {
int r;
if ((r = in.read(bytes, offset, length)) == -1)
return r;
md5.Update(bytes, offset, r);
return r;
}
/**
* Returns array of bytes representing hash of the stream as
* finalized for the current state.
* @see MD5#Final
*/
public byte[] hash () {
return md5.Final();
}
public MD5 getMD5() {
return md5;
}
/**
* This method is here for testing purposes only - do not rely
* on it being here.
**/
public static void main(String[] arg) {
try {
////////////////////////////////////////////////////////////////
//
// usage: java com.twmacinta.util.MD5InputStream [--use-default-md5] [--no-native-lib] filename
//
/////////
// determine the filename to use and the MD5 impelementation to use
String filename = arg[arg.length-1];
boolean use_default_md5 = false;
boolean use_native_lib = true;
for (int i = 0; i < arg.length-1; i++) {
if (arg[i].equals("--use-default-md5")) {
use_default_md5 = true;
} else if (arg[i].equals("--no-native-lib")) {
use_native_lib = false;
}
}
// initialize common variables
byte[] buf = new byte[65536];
int num_read;
// Use the default MD5 implementation that comes with Java
if (use_default_md5) {
InputStream in = new BufferedInputStream(new FileInputStream(filename));
java.security.MessageDigest digest = java.security.MessageDigest.getInstance("MD5");
while ((num_read = in.read(buf)) != -1) {
digest.update(buf, 0, num_read);
}
System.out.println(MD5.asHex(digest.digest())+" "+filename);
in.close();
// Use the optimized MD5 implementation
} else {
// disable the native library search, if requested
if (!use_native_lib) {
MD5.initNativeLibrary(true);
}
// calculate the checksum
MD5InputStream in = new MD5InputStream(new BufferedInputStream(new FileInputStream(filename)));
while ((num_read = in.read(buf)) != -1);
System.out.println(MD5.asHex(in.hash())+" "+filename);
in.close();
}
} catch (Exception e) {
e.printStackTrace();
}
}
}