tribble.security
Class StreamDigest

java.lang.Object
  tribble.security.StreamDigest

public class StreamDigest

extends java.lang.Object

Simple cryptographic file digest generator. Reads an input stream and produces a cryptographic message digest from its byte contents.

Since:

2001-05-06

Version:

$Revision: 1.3 $ $Date: 2003/03/22 14:34:01 $

Author:

David R. Tribble, david@tribble.com.
Copyright ©2001 by David R. Tribble, all rights reserved.
Permission is granted to freely use and distribute this source code provided that the original copyright and authorship notices remain intact.

Field Summary

static int	BLKSIZE Input block size (in bytes).
static java.lang.String	CLASS_NAME This class name.
static java.lang.String	DFL_ALG Default message digest algorithm ("MD5").
protected java.lang.String	m_alg Message digest algorithm.
protected java.security.MessageDigest	m_dig Cryptographic message digest engine.
protected java.io.InputStream	m_in Byte input stream.

Constructor Summary

StreamDigest()
Default constructor.

StreamDigest(java.io.InputStream in)
Constructor.

StreamDigest(java.io.InputStream in, java.lang.String alg)
Constructor.

Method Summary

void	close() Closes the input stream.
java.lang.String	digest() Reads the contents of the input stream, producing a cryptographic message digest, and returning it as a printable text string.
java.lang.String	getAlgorithm() Retrieves the cryptographic message digest algorithm to use.
java.io.InputStream	getInput() Retrieves the input stream from which to read bytes.
static void	main(java.lang.String[] args) Runs this class as a program.
protected static void	run(java.lang.String[] args) Runs this class as a program.
void	setAlgorithm(java.lang.String alg) Establishes the cryptographic message digest algorithm to use.
void	setInput(java.io.InputStream in) Establishes the input stream from which to read bytes.
protected static void	usage() Displays a program usage message, then punts.

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_NAME

public static final java.lang.String CLASS_NAME

This class name.

DFL_ALG

public static final java.lang.String DFL_ALG

Default message digest algorithm ("MD5").

See Also:

Constant Field Values

BLKSIZE

public static final int BLKSIZE

Input block size (in bytes).

See Also:

Constant Field Values

m_in

protected java.io.InputStream m_in

Byte input stream.

m_alg

protected java.lang.String m_alg

Message digest algorithm.

m_dig

protected java.security.MessageDigest m_dig

Cryptographic message digest engine.

Constructor Detail

StreamDigest

public StreamDigest()

Default constructor.

Since:

1.1, 2001-05-06

StreamDigest

public StreamDigest(java.io.InputStream in)

Constructor. Establishes the input stream.

Parameters:

in - The input stream from which to read bytes.

Since:

1.1, 2001-05-06

StreamDigest

public StreamDigest(java.io.InputStream in,
                    java.lang.String alg)
             throws java.security.NoSuchAlgorithmException

Constructor. Establishes the input stream and the cryptographic message digest algorithm to use.

Parameters:

in - The input stream from which to read bytes.

alg - The cryptographic message digest algorithm to use.

Throws:

java.security.NoSuchAlgorithmException - Thrown if alg does not specify a supported digest algorithm.

Since:

1.1, 2001-05-06

Method Detail

main

public static void main(java.lang.String[] args)
                 throws java.lang.Exception

Runs this class as a program.

Parameters:

args - The command line arguments.

Throws:

java.lang.Exception

Since:

1.1, 2001-05-06

setAlgorithm

public void setAlgorithm(java.lang.String alg)
                  throws java.security.NoSuchAlgorithmException

Establishes the cryptographic message digest algorithm to use.

Parameters:

alg - The cryptographic message digest algorithm to use.

Throws:

java.security.NoSuchAlgorithmException - Thrown if alg does not specify a supported digest algorithm.

Since:

1.1, 2001-05-06

getAlgorithm

public java.lang.String getAlgorithm()

Retrieves the cryptographic message digest algorithm to use.

Returns:

The cryptographic message digest algorithm to use.

Since:

1.1, 2001-05-06

setInput

public void setInput(java.io.InputStream in)

Establishes the input stream from which to read bytes.

Parameters:

in - The input stream from which to read bytes.

Since:

1.1, 2001-05-06

getInput

public java.io.InputStream getInput()

Retrieves the input stream from which to read bytes.

Returns:

The input stream from which to read bytes.

Since:

1.1, 2001-05-06

close

public void close()

Closes the input stream.

Since:

1.1, 2001-05-06

digest

public java.lang.String digest()
                        throws java.io.IOException,
                               java.security.NoSuchAlgorithmException

Reads the contents of the input stream, producing a cryptographic message digest, and returning it as a printable text string.

Returns:

The resulting cryptographic message digest as a printable string of hex digits.

Throws:

java.io.IOException - Thrown if an I/O error occurs.

java.security.NoSuchAlgorithmException - Thrown if an unsupported digest algorithm is used.

Since:

1.1, 2001-05-06

usage

protected static void usage()

Displays a program usage message, then punts.

Reads the contents of one of more files, computing a cryptographic message digest, and writes the resulting digest for each one to the standard output.

Usage

    java tribble.security.StreamDigest file...
 

If file is "-", input is read from the standard input.

Since:

1.1, 2001-05-06

run

protected static void run(java.lang.String[] args)
                   throws java.io.IOException,
                          java.security.NoSuchAlgorithmException

Runs this class as a program.

Reads the contents of one of more files, computing a cryptographic message digest, and writes the resulting digest for each one to the standard output.

Usage
See usage().

Parameters:

args - The command line arguments.

Throws:

java.io.IOException

java.security.NoSuchAlgorithmException

Since:

1.1, 2001-05-06