From owner-freebsd-hackers  Sun Sep 27 15:44:04 1998
Return-Path: <owner-freebsd-hackers@FreeBSD.ORG>
Received: (from majordom@localhost)
          by hub.freebsd.org (8.8.8/8.8.8) id PAA03013
          for freebsd-hackers-outgoing; Sun, 27 Sep 1998 15:44:04 -0700 (PDT)
          (envelope-from owner-freebsd-hackers@FreeBSD.ORG)
Received: from ns1.yes.no (ns1.yes.no [195.119.24.10])
          by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id PAA02944
          for <freebsd-hackers@FreeBSD.ORG>; Sun, 27 Sep 1998 15:43:44 -0700 (PDT)
          (envelope-from eivind@bitbox.follo.net)
Received: from bitbox.follo.net (bitbox.follo.net [195.204.143.218])
	by ns1.yes.no (8.9.1a/8.9.1) with ESMTP id AAA08882;
	Mon, 28 Sep 1998 00:43:26 +0200 (CEST)
Received: (from eivind@localhost)
	by bitbox.follo.net (8.8.8/8.8.6) id AAA21319;
	Mon, 28 Sep 1998 00:43:26 +0200 (MET DST)
Message-ID: <19980928004325.25164@follo.net>
Date: Mon, 28 Sep 1998 00:43:25 +0200
From: Eivind Eklund <eivind@yes.no>
To: kim dong chun <mindmap@netian.com>, freebsd-hackers@FreeBSD.ORG
Subject: Re: your mail
References: <199809272149.GAA25116@mail.netian.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
X-Mailer: Mutt 0.89.1i
In-Reply-To: <199809272149.GAA25116@mail.netian.com>; from kim dong chun on Mon, Sep 28, 1998 at 06:49:12AM +0900
Sender: owner-freebsd-hackers@FreeBSD.ORG
Precedence: bulk
X-Loop: FreeBSD.ORG

On Mon, Sep 28, 1998 at 06:49:12AM +0900, kim dong chun wrote:
> Hello!
> 
> My name is dong chun kim.
> 
> I want crack file that is mp3play.ocx 
> 
> Help me... ! 
> 
> Can You?

Yes.  Here is pseudo-code for how to do this:

filesize = (Get the size of the file)
bufferA = malloc(filesize);
BufferB = malloc(filesize);
read-your-file-into-bufferA
rnd = fopen("/dev/random", "r");
/* Optimize for the case where bufferA already contain good data - a
   do-while would be a few cycles faster on average, but not for the
   simple case */
memcpy(bufferB, bufferA, filesize);
while (bufferB does not contain a program doing what you want) {
	memcpy(bufferB, bufferA, filesize);
	for (i=0; i<filesize; i++) {
		bufferB[i] ^= getchar(rnd);
	}
}

... and you're done!  Now, you just have to write the evaluation
function.

Eivind.

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message