goldengate.common.digest
Class MD5

java.lang.Object
  goldengate.common.digest.MD5

public class MD5
extends Object

Fast implementation of RSA's MD5 hash generator in Java JDK Beta-2 or higher.

Originally written by Santeri Paavolainen, Helsinki Finland 1996.
(c) Santeri Paavolainen, Helsinki Finland 1996
Many changes Copyright (c) 2002 - 2005 Timothy W Macinta

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.

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.

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.

See http://www.twmacinta.com/myjava/fast_md5.php for more information on this file and the related files.

This was originally a rather straight re-implementation of the reference implementation given in RFC1321 by RSA. It passes the MD5 test suite as defined in RFC1321.

Many optimizations made by Timothy W Macinta. Reduced time to checksum a test file in Java alone to roughly half the time taken compared with java.security.MessageDigest (within an intepretter). Also added an optional native method to reduce the time even further. See http://www.twmacinta.com/myjava/fast_md5.php for further information on the time improvements achieved.

Some bug fixes also made by Timothy W Macinta.

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.

This Java class has been derived from the RSA Data Security, Inc. MD5 Message-Digest Algorithm and its reference implementation.

This class will attempt to use a native method to quickly compute checksums when the appropriate native library is available. On Linux, this library should be named "MD5.so" and on Windows it should be named "MD5.dll". The code will attempt to locate the library in the following locations in the order given:

1. The path specified by the system property "com.twmacinta.util.MD5.NATIVE_LIB_FILE" (be sure to include "MD5.so" or "MD5.dll" as appropriate at the end of the path).
2. A platform specific directory beneath the "lib/arch/" directory. On Linux for x86, this is "lib/arch/linux_x86/". On Windows for x86, this is "lib/arch/win32_x86/".
3. Within the "lib/" directory.
4. Within the current directory.

If the library is not found, the code will fall back to the default (slower) Java code.

As a side effect of having the code search for the native library, SecurityExceptions might be thrown on JVMs that have a restrictive SecurityManager. The initialization code attempts to silently discard these exceptions and continue, but many SecurityManagers will attempt to notify the user directly of all SecurityExceptions thrown. Consequently, the code has provisions for skipping the search for the native library. Any of these provisions may be used to skip the search as long as they are performed before the first instance of a com.twmacinta.util.MD5 object is constructed (note that the convenience stream objects will implicitly create an MD5 object).

The first option is to set the system property "com.twmacinta.util.MD5.NO_NATIVE_LIB" to "true" or "1". Unfortunately, SecurityManagers may also choose to disallow system property setting, so this won't be of use in all cases.

The second option is to call com.twmacinta.util.MD5.initNativeLibrary(true) before any MD5 objects are constructed.

Author:

Santeri Paavolainen , Timothy W Macinta (twm@alum.mit.edu) (optimizations and bug fixes), Frederic Bregier Bregier (add NIO support and dynamic library path loading)

Constructor Summary

MD5()
Class constructor

MD5(Object ob)
Initialize class, and update hash with ob.toString()

Method Summary

static byte[]	asByte(String buf) Turns String into array of bytes representing each couple of unsigned hex number as one byte.
String	asHex() Returns 32-character hex representation of this objects hash
static String	asHex(byte[] hash) Turns array of bytes into string representing each byte as unsigned hex number.
static boolean	equalPasswd(byte[] pwd, byte[] cryptPwd)
static boolean	equalPasswd(String pwd, String cryptPwd)
byte[]	Final() Returns array of bytes (16 bytes) representing hash as of the current state of this object.
static byte[]	getHash(File f) Calculates and returns the hash of the contents of the given file.
static byte[]	getHash(InputStream stream) Calculates and returns the hash of the contents of the given stream.
static byte[]	getHashNio(File f) Calculates and returns the hash of the contents of the given file using Nio file access.
static boolean	hashesEqual(byte[] hash1, byte[] hash2) Test if both hashes are equal
void	Init() Initialize MD5 internal state (object can be reused just by calling Init() after every Final()
static boolean	initNativeLibrary(boolean disallow_lib_loading) Disable lib loading (True) or enable it (false)
static boolean	initNativeLibrary(String libpath) Initialize the Native Library from path
static void	main(String[] argv) Test function
static byte[]	passwdCrypt(byte[] bpwd) Crypt a password
static String	passwdCrypt(String pwd) Crypt a password
void	Update(byte b) Updates hash with a single byte
void	Update(byte[] buffer) Updates hash with given array of bytes
void	Update(byte[] buffer, int length) Plain update, updates this object
void	Update(byte[] buffer, int offset, int length) Plain update, updates this object
void	Update(org.jboss.netty.buffer.ChannelBuffer buffer) Updates hash with given ChannelBuffer (from Netty)
void	Update(int i) Update buffer with a single integer (only & 0xff part is used, as a byte)
void	Update(goldengate.common.digest.MD5State stat, byte[] buffer, int offset, int length) Updates hash with the bytebuffer given (using at maximum length bytes from that buffer)
void	Update(String s) Update buffer with given string.
void	Update(String s, String charset_name) Update buffer with given string using the given encoding.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

MD5

public MD5()

Class constructor

MD5

public MD5(Object ob)

Initialize class, and update hash with ob.toString()

Parameters:

ob - Object, ob.toString() is used to update hash after initialization

Method Detail

Init

public void Init()

Initialize MD5 internal state (object can be reused just by calling Init() after every Final()

Update

public void Update(goldengate.common.digest.MD5State stat,
                   byte[] buffer,
                   int offset,
                   int length)

Updates hash with the bytebuffer given (using at maximum length bytes from that buffer)

Parameters:

stat - Which state is updated

buffer - Array of bytes to be hashed

offset - Offset to buffer array

length - Use at maximum `length' bytes (absolute maximum is buffer.length)

Update

public void Update(byte[] buffer,
                   int offset,
                   int length)

Plain update, updates this object

Parameters:

buffer -

offset -

length -

Update

public void Update(byte[] buffer,
                   int length)

Plain update, updates this object

Parameters:

buffer -

length -

Update

public void Update(byte[] buffer)

Updates hash with given array of bytes

Parameters:

buffer - Array of bytes to use for updating the hash

Update

public void Update(byte b)

Updates hash with a single byte

Parameters:

b - Single byte to update the hash

Update

public void Update(String s)

Update buffer with given string. Note that because the version of the s.getBytes() method without parameters is used to convert the string to a byte array, the results of this method may be different on different platforms. The s.getBytes() method converts the string into a byte array using the current platform's default character set and may therefore have different results on platforms with different default character sets. If a version that works consistently across platforms with different default character sets is desired, use the overloaded version of the Update() method which takes a string and a character encoding.

Parameters:

s - String to be update to hash (is used as s.getBytes())

Update

public void Update(String s,
                   String charset_name)
            throws UnsupportedEncodingException

Update buffer with given string using the given encoding. If the given encoding is null, the encoding "ISO8859_1" is used.

Parameters:

s - String to be update to hash (is used as s.getBytes(charset_name))

charset_name - The character set to use to convert s to a byte array, or null if the "ISO8859_1" character set is desired.

Throws:

UnsupportedEncodingException - If the named charset is not supported.

Update

public void Update(int i)

Update buffer with a single integer (only & 0xff part is used, as a byte)

Parameters:

i - Integer value, which is then converted to byte as i & 0xff

Update

public void Update(org.jboss.netty.buffer.ChannelBuffer buffer)

Updates hash with given ChannelBuffer (from Netty)

Parameters:

buffer - ChannelBuffer to use for updating the hash and this buffer will not be changed

Final

public byte[] Final()

Returns array of bytes (16 bytes) representing hash as of the current state of this object. Note: getting a hash does not invalidate the hash object, it only creates a copy of the real state which is finalized.

Returns:

Array of 16 bytes, the hash of all updated bytes

asHex

public static final String asHex(byte[] hash)

Turns array of bytes into string representing each byte as unsigned hex number.

Parameters:

hash - Array of bytes to convert to hex-string

Returns:

Generated hex string

asByte

public static final byte[] asByte(String buf)

Turns String into array of bytes representing each couple of unsigned hex number as one byte.

Parameters:

buf - hex string

Returns:

Array of bytes converted from hex-string

asHex

public String asHex()

Returns 32-character hex representation of this objects hash

Returns:

String of this object's hash

initNativeLibrary

public static final boolean initNativeLibrary(boolean disallow_lib_loading)

Disable lib loading (True) or enable it (false)

Parameters:

disallow_lib_loading -

Returns:

True if the native Library is loaded, else False

initNativeLibrary

public static final boolean initNativeLibrary(String libpath)

Initialize the Native Library from path

Parameters:

libpath -

Returns:

True if the native Library is loaded, else False

getHash

public static byte[] getHash(File f)
                      throws IOException

Calculates and returns the hash of the contents of the given file.

Parameters:

f - FileInterface to hash

Returns:

the hash from the given file

Throws:

IOException

getHashNio

public static byte[] getHashNio(File f)
                         throws IOException

Calculates and returns the hash of the contents of the given file using Nio file access.

Parameters:

f - for the FileInterface

Returns:

the hash from the FileInterface with NIO access

Throws:

IOException

getHash

public static byte[] getHash(InputStream stream)
                      throws IOException

Calculates and returns the hash of the contents of the given stream.

Parameters:

stream - Stream to hash

Returns:

the hash from the given stream

Throws:

IOException

hashesEqual

public static boolean hashesEqual(byte[] hash1,
                                  byte[] hash2)

Test if both hashes are equal

Parameters:

hash1 -

hash2 -

Returns:

true iff the first 16 bytes of both hash1 and hash2 are equal; both hash1 and hash2 are null; or either hash array is less than 16 bytes in length and their lengths and all of their bytes are equal.

passwdCrypt

public static final String passwdCrypt(String pwd)

Crypt a password

Parameters:

pwd - to crypt

Returns:

the crypted password

passwdCrypt

public static final byte[] passwdCrypt(byte[] bpwd)

Crypt a password

Parameters:

bpwd - to crypt

Returns:

the crypted password

equalPasswd

public static final boolean equalPasswd(String pwd,
                                        String cryptPwd)

Parameters:

pwd -

cryptPwd -

Returns:

True if the pwd is comparable with the cryptPwd

equalPasswd

public static final boolean equalPasswd(byte[] pwd,
                                        byte[] cryptPwd)

Parameters:

pwd -

cryptPwd -

Returns:

True if the pwd is comparable with the cryptPwd

main

public static void main(String[] argv)

Test function

Parameters:

argv - with 2 arguments as filename to hash and full path to the Native Library