hashmac.java

JAVA的加密源程序

/*
Christoforos Pirillos @ Villanova University - May 1999
based on code from the book "Java Network Programming" by Hughes
*/

package encryption;

/** Message Authentication Code. It takes an existing hash algorithm and
encryption algorithm and combines them to form a MAC*/

public class HashMAC extends Hash {

protected Hash h;
protected Cipher c;

public HashMAC (Hash h, Cipher c) {
	this.h = h;
	this.c = c;
}

public byte[] digest (byte[] text, int off, int len) {
	byte[] hash = h.digest (text, off, len);
	return c.encipher (hash, 0, Math.min (hash.length,
c.blockSize()));
}

public int digestSize () {
	return c.blockSize();
}

}