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/* From http://java.sun.com/docs/books/tutorial/index.html */
/*
* Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* -Redistribution of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* -Redistribution in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of Sun Microsystems, Inc. or the names of contributors may
* be used to endorse or promote products derived from this software without
* specific prior written permission.
*
* This software is provided "AS IS," without a warranty of any kind. ALL
* EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING
* ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE
* OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN")
* AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE
* AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS
* DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST
* REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL,
* INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY
* OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE,
* EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
*
* You acknowledge that this software is not designed, licensed or intended
* for use in the design, construction, operation or maintenance of any
* nuclear facility.
*/
import java.io.FileInputStream;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.SecureRandom;
import java.security.Signature;
public class testSig {
public static void main(String[] args) {
/* Test generating and verifying a DSA signature */
try {
/* generate a key pair */
KeyPairGenerator keyGen = KeyPairGenerator.getInstance("DSA");
keyGen.initialize(1024, new SecureRandom());
KeyPair pair = keyGen.generateKeyPair();
/*
* create a Signature object to use for signing and verifying
*/
Signature dsa = Signature.getInstance("SHA/DSA");
/* initialize the Signature object for signing */
PrivateKey priv = pair.getPrivate();
dsa.initSign(priv);
/* Update and sign the data */
FileInputStream fis = new FileInputStream(args[0]);
byte b;
while (fis.available() != 0) {
b = (byte) fis.read();
dsa.update(b);
}
;
fis.close();
/*
* Now that all the data to be signed has been read in, sign it
*/
byte[] sig = dsa.sign();
/* Verify the signature */
/* Initialize the Signature object for verification */
PublicKey pub = pair.getPublic();
dsa.initVerify(pub);
/* Update and verify the data */
fis = new FileInputStream(args[0]);
while (fis.available() != 0) {
b = (byte) fis.read();
dsa.update(b);
}
;
fis.close();
boolean verifies = dsa.verify(sig);
System.out.println("signature verifies: " + verifies);
} catch (Exception e) {
System.err.println("Caught exception " + e.toString());
}
}
}
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