/*

** Copyright 1998 - 1999 Double Precision, Inc.  See COPYING for

** distribution information.

*/

#if	HAVE_CONFIG_H

#include	"config.h"

#endif

#include	<sys/types.h>

#if	HAVE_UNISTD_H

#include	<unistd.h>

#endif

#include	<stdio.h>

#include	<stdlib.h>

#include	<grp.h>

#include	<pwd.h>

#include	<errno.h>

#include	"auth.h"

static const char rcsid[]="$Id: changeuidgid.c,v 1.1 2000/04/13 17:55:05 bruce Exp $";

void authchangegroup(gid_t gid)

{

	if ( setgid(gid))

	{

		perror("setgid");

		authexit(1);

	}

#if HAVE_SETGROUPS

	if ( getuid() == 0 && setgroups(1, &gid) )

	{

		perror("setgroups");

		authexit(1);

	}

#endif

}

void authchangeuidgid(uid_t uid, gid_t gid)

{

	authchangegroup(gid);

	if ( setuid(uid))

	{

		perror("setuid");

		authexit(1);

	}

}

void authchangeusername(const char *uname, const gid_t *forcegrp)

{

struct passwd *pw;

uid_t	changeuid;

gid_t	changegid;

/* uname might be a pointer returned from a previous called to getpw(),

** and libc has a problem getting it back.

*/

char	*p=malloc(strlen(uname)+1);

	if (!p)

	{

		perror("malloc");

		authexit(1);

	}

	strcpy(p, uname);

	errno=ENOENT;

	if ((pw=getpwnam(p)) == 0)

	{

		free(p);

		perror("getpwnam");

		authexit(1);

	}

	free(p);

	changeuid=pw->pw_uid;

	if ( !forcegrp )	forcegrp= &pw->pw_gid;

	changegid= *forcegrp;

	if ( setgid( changegid ))

	{

		perror("setgid");

		authexit(1);

	}

#if HAVE_INITGROUPS

	if ( getuid() == 0 && initgroups(pw->pw_name, changegid) )

	{

		perror("initgroups");

		authexit(1);

	}

#else

#if HAVE_SETGROUPS

	if ( getuid() == 0 && setgroups(1, &changegid) )

	{

		perror("setgroups");

		authexit(1);

	}

#endif

#endif

	if (setuid(changeuid))

	{

		perror("setuid");

		authexit(1);

	}

}