Re: passwd character limitations

[Peter Cordes <peter@llama.nslug.ns.ca>]

On Fri, Oct 31, 2003 at 06:41:20PM -0500, Michael Stone wrote:
> >I'm looking for a list of characters that are not allowable (or that
> >cause problems) for passwords if any under a standard Debian GNU/Linux
> >install (using md5).  
> 
> AFAIK, there aren't any. You may run into limitations in particular
> programs,

 Like that most programs expect the password to be typed on a cooked tty, so
these are treated specially:

intr = ^C; quit = ^\; erase = ^?; kill = ^U; eof = ^D; eol = <undef>;
eol2 = <undef>; start = ^Q; stop = ^S; susp = ^Z; rprnt = ^R; werase = ^W;
(run stty -a to check your terminal settings).

 You might need to use a specially-written ssh client to log in if you do
anything too weird.  If you mess up root's password, you might have some
real trouble if ssh won't let you log in a root, because su(1), getty(8) and
login(1) all use cooked ttys.  (Maybe you could stty raw < /dev/pts/x,
from another session, type your password, and then  stty cooked < /dev/pts/x.)

> but there shouldn't be any limits on the input to the hash
> function whose output is stored in the shadow file.[0]

-- 
#define X(x,y) x##y
Peter Cordes ;  e-mail: X(peter@cor , des.ca)

"The gods confound the man who first found out how to distinguish the hours!
 Confound him, too, who in this place set up a sundial, to cut and hack
 my day so wretchedly into small pieces!" -- Plautus, 200 BC