/etc/shadow

[The Beach Bum]

In article <1337 at tmpmbx.UUCP>, pengo at tmpmbx.UUCP (Hans H. Huebner) writes:
> Hello,
> 
> developers interested in a library which confirms to the AT&T shadow password
> file scheme as described by Dennis, send me a short note.  I have hacked
> together what Dennis specified in his earlier note, but I can't guarantee
> that it works *exactly* the same way AT&T does it.
> 
> If there's enough interest, I'll post the stuff to rsalz and alt.sources as
> soon as I have the manual pages finished.

I got impatient.  Attached is my clone which I'll be including in the soon
to be released login clone.  The routines were all very simple, I didn't
see any point in holding out ...

This was all written straight off of Dennis' article.  You may do with it
as you please.  So much for security by obscurity [ Thanks James ... ]
It is as simple minded as possible, your suggestions, as always, are
more than welcome.

- John.
--
#! /bin/sh
# This is a shell archive, meaning:
# 1. Remove everything above the #! /bin/sh line.
# 2. Save the resulting text in a file.
# 3. Execute the file with /bin/sh (not csh) to create:
#	shadow.c
#	shadow.h
# This archive created: Fri Nov 18 00:07:19 1988
export PATH; PATH=/bin:/usr/bin:$PATH
if test -f 'shadow.c'
then
	echo shar: "will not over-write existing file 'shadow.c'"
else
cat << \SHAR_EOF > 'shadow.c'
#include "shadow.h"
#include <stdio.h>
#include <string.h>

static	FILE	*shadow;

void	setspent ()
{
	if (shadow)
		rewind (shadow);
	else
		shadow = fopen (SHADOW, "r");
}

void	endspent ()
{
	if (shadow)
		fclose (shadow);
}

struct	spwd	*fgetspent (fp)
FILE	*fp;
{
	static	struct	spwd	spwd;
	static	char	name[32];
	static	char	pass[32];
	char	buf[BUFSIZ];
	char	*cp;
	int	atoi ();
	long	atol ();

	if (! fp)
		return (0);

	if (fgets (buf, BUFSIZ, fp) == (char *) 0)
		return (0);

	if ((cp = strtok (buf, ":")) && *cp)
		strcpy (name, cp);
	else
		return (0);

	if ((cp = strtok ((char *) 0, ":")) && *cp)
		strcpy (pass, cp);
	else
		return (0);

	if ((cp = strtok ((char *) 0, ":")) && *cp)
		spwd.sp_lstchg = atol (cp);
	else
		return (0);

	if ((cp = strtok ((char *) 0, ":")) && *cp)
		spwd.sp_min = atoi (cp);
	else
		return (0);

	if ((cp = strtok ((char *) 0, ":")) && *cp)
		spwd.sp_max = atoi (cp);
	else
		return (0);

	spwd.sp_namp = name;
	spwd.sp_pwdp = pass;

	return (&spwd);
}

struct	spwd	*getspent ()
{
	return (fgetspent (shadow));
}

struct	spwd	*getspnam (name)
char	*name;
{
	struct	spwd	*spwd;

	setspent ();

	while ((spwd = getspent ()) != (struct spwd *) 0) {
		if (strcmp (name, spwd->sp_namp) == 0)
			return (spwd);
	}
	return (0);
}

int	putspent (spwd, fp)
struct	spwd	*spwd;
FILE	*fp;
{
	if (! fp)
		return (0);

	return (fprintf (fp, "%s:%s:%ld:%d:%d\n",
			spwd->sp_namp, spwd->sp_pwdp,
			spwd->sp_lstchg, spwd->sp_min, spwd->sp_max) > 0);
}
SHAR_EOF
fi
if test -f 'shadow.h'
then
	echo shar: "will not over-write existing file 'shadow.h'"
else
cat << \SHAR_EOF > 'shadow.h'
/*
 * This information is not derived from AT&T licensed sources.  Posted
 * to the USENET 11/88.
 */

/*
 * Shadow password security file structure.
 */

struct	spwd {
	char	*sp_namp;	/* login name */
	char	*sp_pwdp;	/* encrypted password */
	long	sp_lstchg;	/* date of last change */
	int	sp_max;		/* maximum number of days between changes */
	int	sp_min;		/* minimum number of days between changes */
};

/*
 * Shadow password security file functions.
 */

struct	spwd	*getspent ();
struct	spwd	*getspnam ();
void	setspent ();
void	endspent ();
struct	spwd	*fgetspent ();
int	putspent ();

#define  SHADOW "/etc/shadow"
SHAR_EOF
fi
exit 0
#	End of shell archive
-- 
John F. Haugh II                        +----------Quote of the Week:----------
VoiceNet: (214) 250-3311   Data: -6272  | "Okay, so maybe Berkeley is in north-
InterNet: jfh at rpp386.Dallas.TX.US       |   ern California." -- Henry Spencer
UucpNet : <backbone>!killer!rpp386!jfh  +--------------------------------------