These four programs all operate on the normal and shadow password and
group files:
/etc/passwd , /etc/group , /etc/shadow , and /etc/gshadow .
pwconv
creates shadow from passwd and an optionally existing shadow .
pwunconv
creates passwd from passwd and shadow and then removes shadow .
grpconv
creates gshadow from group and an optionally existing gshadow .
grpunconv
creates group from group and gshadow and then removes gshadow .
Each program acquires the necessary locks before conversion.
pwconv and grpconv
are similiar. First, entries in the shadowed file which don't exist
in the main file are removed. Then, shadowed entries which don't have
`x' as the password in the main file are updated. Any missing
shadowed entries are added. Finally, passwords in the main file are
replaced with `x'. These programs can be used for initial conversion
as well to update the shadowed file if the main file is edited by
hand.
pwconv
will use the values of
PASS_MIN_DAYS , PASS_MAX_DAYS , and PASS_WARN_AGE
from
/etc/login.defs
when adding new entries to
/etc/shadow .
Likewise, pwunconv and grpunconv
are similiar. Passwords in the main file are updated from the
shadowed file. Entries which exist in the main file but not in the
shadowed file are left alone. Finally, the shadowed file is removed.
Some password aging information is lost by
pwunconv .
It will convert what it can.