Date: Wed, 13 May 1998 16:06:49 -0700 (PDT)
From: Yuri Romanenko <yuri@CS.UCLA.EDU>
To: Roland Schemers <Roland.Schemers@Eng>
Subject: Re: can't compile the sample code for JCE1.2
In-Reply-To: <199805132259.PAA04232@crypto.eng.sun.com>
thanks for the fast response. Here's a segment that doesn't compile and
below is the complete program. It's hard to see what the loop should
contain... since 'i' isn't really used anywhere...
// Compare Alice and Bob
if (aliceLen != bobLen) {
throw new Exception("Alice and Bob have different lengths");
}
for (int i=0; i> 4);
int low = (b & 0x0f);
buf.append(hexChars[high]);
buf.append(hexChars[low]);
Thanks a lot for your help!!!
Yuri Romanenko
yuri@cs.ucla.edu
here's the whole program from the API_users_guide.html
======
/*
* Copyright 1993-1997 Sun Microsystems, Inc. 901 San Antonio Road,
* Palo Alto, California, 94303, U.S.A. All Rights Reserved.
*
* This software is the confidential and proprietary information of Sun
* Microsystems, Inc. ("Confidential Information"). You shall not
* disclose such Confidential Information and shall use it only in
* accordance with the terms of the license agreement you entered into
* with Sun.
*
* CopyrightVersion 1.2
*
*/
import java.io.*;
import java.math.BigInteger;
import java.security.*;
import java.security.spec.*;
import java.security.interfaces.*;
import javax.crypto.*;
import javax.crypto.spec.*;
import javax.crypto.interfaces.*;
import com.sun.crypto.provider.SunJCE;
/**
* This test utility executes the Diffie-Hellman key agreement protocol
* between 2 parties: Alice and Bob.
*
* By default, preconfigured parameters (1024 bit prime modulus and base
* generator used by SKIP) are used.
* If this program is called with the "-gen" option, a new set of
parameters
* (512 bit prime modulus and base generator) are created. (Parameter
* generation takes a very long time to complete!)
*/
public class DHKeyAgreement2 {
private DHKeyAgreement2() {}
public static void main(String argv[]) {
try {
String mode = "USE_SKIP_DH_PARAMS";
// Add JCE to the list of providers
SunJCE jce = new SunJCE();
Security.addProvider(jce);
DHKeyAgreement2 keyAgree = new DHKeyAgreement2();
if (argv.length > 1) {
keyAgree.usage();
throw new Exception("Wrong number of command options");
} else if (argv.length == 1) {
if (!(argv[0].equals("-gen"))) {
keyAgree.usage();
throw new Exception("Unrecognized flag: " + argv[0]);
}
mode = "GENERATE_DH_PARAMS";
}
keyAgree.run(mode);
} catch (Exception e) {
System.err.println("Error: " + e);
System.exit(1);
}
}
private void run(String mode) throws Exception {
DHParameterSpec dhSkipParamSpec;
if (mode.equals("GENERATE_DH_PARAMS")) {
// Some central authority creates new DH parameters
System.err.println
("Creating Diffie-Hellman parameters (takes VERY long)
...");
AlgorithmParameterGenerator paramGen
= AlgorithmParameterGenerator.getInstance("DH");
paramGen.init(512);
AlgorithmParameters params = paramGen.generateParameters();
dhSkipParamSpec = (DHParameterSpec)params.getParameterSpec
(DHParameterSpec.class);
} else {
// use some pre-generated, default DH parameters
System.err.println("Using SKIP Diffie-Hellman parameters");
dhSkipParamSpec = new DHParameterSpec(skip1024Modulus,
skip1024Base);
}
/*
* Alice creates her own DH key pair, using the DH parameters from
* above
*/
System.err.println("ALICE: Generate DH keypair ...");
KeyPairGenerator aliceKpairGen =
KeyPairGenerator.getInstance("DH");
aliceKpairGen.initialize(dhSkipParamSpec);
KeyPair aliceKpair = aliceKpairGen.generateKeyPair();
// Alice executes Phase1 of her version of the DH protocol
System.err.println("ALICE: Execute PHASE1 ...");
KeyAgreement aliceKeyAgree = KeyAgreement.getInstance("DH");
aliceKeyAgree.init(aliceKpair.getPrivate());
// Alice encodes her public key, and sends it over to Bob.
byte[] alicePubKeyEnc = aliceKpair.getPublic().getEncoded();
/*
* Let's turn over to Bob. Bob has received Alice's public key
* in encoded format.
* He instantiates a DH public key from the encoded key material.
*/
KeyFactory bobKeyFac = KeyFactory.getInstance("DH");
X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec
(alicePubKeyEnc);
PublicKey alicePubKey = bobKeyFac.generatePublic(x509KeySpec);
/*
* Bob gets the DH parameters associated with Alice's public key.
* He must use the same parameters when he generates his own key
* pair.
*/
DHParameterSpec dhParamSpec =
((DHPublicKey)alicePubKey).getParams();
// Bob creates his own DH key pair
System.err.println("BOB: Generate DH keypair ...");
KeyPairGenerator bobKpairGen = KeyPairGenerator.getInstance("DH");
bobKpairGen.initialize(dhParamSpec);
KeyPair bobKpair = bobKpairGen.generateKeyPair();
// Bob executes Phase1 of his version of the DH protocol
System.err.println("BOB: Execute PHASE1 ...");
KeyAgreement bobKeyAgree = KeyAgreement.getInstance("DH");
bobKeyAgree.init(bobKpair.getPrivate());
// Bob encodes his public key, and sends it over to Alice.
byte[] bobPubKeyEnc = bobKpair.getPublic().getEncoded();
/*
* Alice uses Bob's public key for Phase2 of her version of the DH
* protocol.
* Before she can do so, she has to instanticate a DH public key
* from Bob's encoded key material.
*/
KeyFactory aliceKeyFac = KeyFactory.getInstance("DH");
x509KeySpec = new X509EncodedKeySpec(bobPubKeyEnc);
PublicKey bobPubKey = aliceKeyFac.generatePublic(x509KeySpec);
System.err.println("ALICE: Execute PHASE2 ...");
aliceKeyAgree.doPhase(bobPubKey, true);
/*
* Bob uses Alice's public key for Phase2 of his version of the DH
* protocol.
*/
System.err.println("BOB: Execute PHASE2 ...");
bobKeyAgree.doPhase(alicePubKey, true);
/*
* At this stage, both Alice and Bob have completed the DH key
* agreement protocol.
* Each generates the (same) shared secret.
*/
byte[] aliceSharedSecret = aliceKeyAgree.generateSecret();
int aliceLen = aliceSharedSecret.length;
byte[] bobSharedSecret = new byte[aliceLen];
int bobLen;
try {
// provide output buffer that is too short
bobLen = bobKeyAgree.generateSecret(bobSharedSecret, 1);
} catch (ShortBufferException e) {
System.out.println(e.getMessage());
}
// provide output buffer of required size
bobLen = bobKeyAgree.generateSecret(bobSharedSecret, 0);
System.out.println("Alice secret: " +
toHexString(aliceSharedSecret));
System.out.println("Bob secret: " + toHexString(bobSharedSecret));
if (aliceLen != bobLen) {
throw new Exception("Shared secrets have different lengths");
}
for (int i=0; i> 4);
int low = (b & 0x0f);
buf.append(hexChars[high]);
buf.append(hexChars[low]);
}
/*
* Converts a byte array to hex string
*/
private String toHexString(byte[] block) {
StringBuffer buf = new StringBuffer();
int len = block.length;
for (int i = 0; i < len; i++) {
byte2hex(block[i], buf);
if (i < len-1) {
buf.append(":");
}
}
return buf.toString();
}
/*
* Prints the usage of this test.
*/
private void usage() {
System.err.print("DHKeyAgreement usage: ");
System.err.println("[-gen]");
}
// The 1024 bit Diffie-Hellman modulus values used by SKIP
private static final byte skip1024ModulusBytes[] = {
(byte)0xF4, (byte)0x88, (byte)0xFD, (byte)0x58,
(byte)0x4E, (byte)0x49, (byte)0xDB, (byte)0xCD,
(byte)0x20, (byte)0xB4, (byte)0x9D, (byte)0xE4,
(byte)0x91, (byte)0x07, (byte)0x36, (byte)0x6B,
(byte)0x33, (byte)0x6C, (byte)0x38, (byte)0x0D,
(byte)0x45, (byte)0x1D, (byte)0x0F, (byte)0x7C,
(byte)0x88, (byte)0xB3, (byte)0x1C, (byte)0x7C,
(byte)0x5B, (byte)0x2D, (byte)0x8E, (byte)0xF6,
(byte)0xF3, (byte)0xC9, (byte)0x23, (byte)0xC0,
(byte)0x43, (byte)0xF0, (byte)0xA5, (byte)0x5B,
(byte)0x18, (byte)0x8D, (byte)0x8E, (byte)0xBB,
(byte)0x55, (byte)0x8C, (byte)0xB8, (byte)0x5D,
(byte)0x38, (byte)0xD3, (byte)0x34, (byte)0xFD,
(byte)0x7C, (byte)0x17, (byte)0x57, (byte)0x43,
(byte)0xA3, (byte)0x1D, (byte)0x18, (byte)0x6C,
(byte)0xDE, (byte)0x33, (byte)0x21, (byte)0x2C,
(byte)0xB5, (byte)0x2A, (byte)0xFF, (byte)0x3C,
(byte)0xE1, (byte)0xB1, (byte)0x29, (byte)0x40,
(byte)0x18, (byte)0x11, (byte)0x8D, (byte)0x7C,
(byte)0x84, (byte)0xA7, (byte)0x0A, (byte)0x72,
(byte)0xD6, (byte)0x86, (byte)0xC4, (byte)0x03,
(byte)0x19, (byte)0xC8, (byte)0x07, (byte)0x29,
(byte)0x7A, (byte)0xCA, (byte)0x95, (byte)0x0C,
(byte)0xD9, (byte)0x96, (byte)0x9F, (byte)0xAB,
(byte)0xD0, (byte)0x0A, (byte)0x50, (byte)0x9B,
(byte)0x02, (byte)0x46, (byte)0xD3, (byte)0x08,
(byte)0x3D, (byte)0x66, (byte)0xA4, (byte)0x5D,
(byte)0x41, (byte)0x9F, (byte)0x9C, (byte)0x7C,
(byte)0xBD, (byte)0x89, (byte)0x4B, (byte)0x22,
(byte)0x19, (byte)0x26, (byte)0xBA, (byte)0xAB,
(byte)0xA2, (byte)0x5E, (byte)0xC3, (byte)0x55,
(byte)0xE9, (byte)0x2F, (byte)0x78, (byte)0xC7
};
// The SKIP 1024 bit modulus
private static final BigInteger skip1024Modulus
= new BigInteger(1, skip1024ModulusBytes);
// The base used with the SKIP 1024 bit modulus
private static final BigInteger skip1024Base = BigInteger.valueOf(2);
}
=====
On Wed, 13 May 1998, Roland Schemers wrote:
> I don't have the code handy but it certainly looks like it should be:
>
> for (int i=0; i < 4; i++)
>
> If there is already an i++ within the for statement/block then it
> should be:
>
> for (int i=0; i < 4;)
>
> roland
>
> > Date: Wed, 13 May 1998 15:51:50 -0700 (PDT)
> > From: Yuri Romanenko <yuri@CS.UCLA.EDU>
> > To: java-security@web2.javasoft.com
> > Subject: can't compile the sample code for JCE1.2
> > MIME-Version: 1.0
> >
> > Hi,
> >
> > I am grad student at UCLA and enrolled in the computer security class.
> > We've been trying to evaluate JCE and apparently we can't compile the
> > sample code for Diffie-Hellman key exchange listed in
> > API_users_guide.html. It complains about the following line:
> >
> > DHKeyAgreement2.java:181: ';' expected.
> > for (int i=0; i> 4);
> > ^
> > 1 error
> >
> > Clearly this "for" loop has a problem. Please check it out and let me
> > know ASAP. Thanks!!
> >
> >
> > Yuri Romanenko
> > yuri@cs.ucla.edu
> >
> >
>
>