From owner-freebsd-questions  Mon Mar 24 10:18:36 2003
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id B5AF937B401
	for <questions@freebsd.org>; Mon, 24 Mar 2003 10:18:31 -0800 (PST)
Received: from login.kvalito.no (login.kvalito.no [213.151.136.2])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 381F643F3F
	for <questions@freebsd.org>; Mon, 24 Mar 2003 10:18:31 -0800 (PST)
	(envelope-from sigsegv@login.kvalito.no)
Received: by login.kvalito.no (Postfix, from userid 1166)
	id AE4EA1276E0; Mon, 24 Mar 2003 19:18:45 +0100 (CET)
To: blueeskimo@gmx.net
Subject: Re: Generating passwords
Cc: questions@freebsd.org, tony@idk.com
Message-Id: <20030324181845.AE4EA1276E0@login.kvalito.no>
Date: Mon, 24 Mar 2003 19:18:45 +0100 (CET)
From: sigsegv@login.kvalito.no (Jan-Espen Pettersen)
X-Spam-Status: No, hits=-9.7 required=5.0
	tests=EMAIL_ATTRIBUTION,QUOTED_EMAIL_TEXT
	autolearn=ham	version=2.50
X-Spam-Level: 
X-Spam-Checker-Version: SpamAssassin 2.50 (1.173-2003-02-20-exp)
Sender: owner-freebsd-questions@FreeBSD.ORG
Precedence: bulk
List-ID: <freebsd-questions.FreeBSD.ORG>
List-Archive: <http://docs.freebsd.org/mail/> (Web Archive)
List-Help: <mailto:majordomo@FreeBSD.ORG?subject=help> (List Instructions)
List-Subscribe: <mailto:majordomo@FreeBSD.ORG?subject=subscribe%20freebsd-questions>
List-Unsubscribe: <mailto:majordomo@FreeBSD.ORG?subject=unsubscribe%20freebsd-questions>
X-Loop: FreeBSD.ORG

On Monday 24 March 2003 07:24, you wrote:
> On Mon, 2003-03-24 at 00:04, Jan-Espen Pettersen wrote:
> > This C program will generate random passwords.
> > ...
> > int main()
> > {
> >  int min_lenght = 8;
> >  int max_lenght = 30;
> >  int a;
> >  long int b;
> >  char *c =
> > "-abcdefghijklmnopqrstuvwxyz-ABCDEFGHIJKLMNOPQRSTUVWXYZ---_/*+1234567890!
> >#---1234567890-"; char *d;
> >  long int e;
> >  srandomdev();
> >  e = random();
> >  e = min_lenght + (e % ((max_lenght - min_lenght) + 1));
> >  printf("lenght=%d\n", e);
> >  e++;
> >  d = (char *) malloc(e);
> >  e--;
> >  d[e] = 0;
> >  a = 0;
> >  while (a < e)
> >  {
> >   b = random();
> >   b = b % strlen(c);
> >   d[a] = c[b];
> >   a++;
> >  };
> >  printf("password=\"%s\"\n", d);
> > };
>
> I have a few issues with this code ..
> a) You never free() your malloc'ed memory
>
> b) You shouldn't call strlen(c) every time you iterate through the
> while() loop (since 'c' isn't changing). Set this length in a variable
> before the while loop, then make use of that variable. This could even
> be a #define, since the string is hard-coded.
>
> c) I'm not sure this is completely portable: d[e] = 0;
> Just in case, I'd suggest: d[e] = '\0';
>
> d) Combine these two lines:
> b = random();
> b = b % strlen(c);
> --> b = random() % len; // using 'len' variable as I mentioned before.
>
> e) You never return from main(). Some compilers will be very unhappy
> about this. Better to be explicit.
>
> f) You don't check the return value of malloc(). This should be a
> no-brainer. *Always* check the return value of malloc/calloc, no matter
> how little memory you are requesting.

Oops, sorry, that program was only a program I wrote relly fast for internal use only. for a very long while ago. I should have checked it for that type of warnings/errors/bad code. 


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