Date: Mon, 30 Aug 2004 16:20:25 GMT From: Ceri Davies <ceri@submonkey.net> To: freebsd-bugs@FreeBSD.org Subject: Re: bin/71147: sshd(8) will allow to log into a locked account Message-ID: <200408301620.i7UGKP9V077390@freefall.freebsd.org>
next in thread | raw e-mail | index | archive | help
The following reply was made to PR bin/71147; it has been noted by GNATS. From: Ceri Davies <ceri@submonkey.net> To: Yar Tikhiy <yar@comp.chem.msu.su> Cc: FreeBSD Gnats Submit <freebsd-gnats-submit@FreeBSD.org> Subject: Re: bin/71147: sshd(8) will allow to log into a locked account Date: Mon, 30 Aug 2004 17:16:02 +0100 On Mon, Aug 30, 2004 at 02:10:30PM +0000, Yar Tikhiy wrote: > The following reply was made to PR bin/71147; it has been noted by GNATS. > > From: Yar Tikhiy <yar@comp.chem.msu.su> > To: Gleb Smirnoff <glebius@freebsd.org> > Cc: FreeBSD-gnats-submit@freebsd.org, des@freebsd.org > Subject: Re: bin/71147: sshd(8) will allow to log into a locked account > Date: Mon, 30 Aug 2004 18:00:21 +0400 > > On Mon, Aug 30, 2004 at 05:50:14PM +0400, Gleb Smirnoff wrote: > > On Mon, Aug 30, 2004 at 04:52:54PM +0400, Yar Tikhiy wrote: > > Y> In FreeBSD (and other BSDs,) the well-known way to lock out > > Y> a user's account is setting the user's encrypted password to > > Y> an asterisk character, `*', in master.passwd. Arguably, one > > Y> can also lock out a user by just _prefixing_ the password field > > Y> value with `*'. Anyway, sshd(8) will ignore either lock > > Y> and allow the user to log in if he authenticates himself by > > Y> means other than the Unix password, e.g., using his public key. > > > > This is not a bug, it's a feature! Any ssh (not only Open) has the > > same behavior on any unix operating system. > > Has it? The sshd(8) manpage says a different thing! And I'll be > damned if the OpenSSH code doesn't check for OS-specific lock strings > in the password hash field. > > > I'm utilizing this feature since I use pubkey authentification. > > I'm afraid it's a dangerous feature to have. Personally, I like > the way described on the sshd(8) manpage: you set the password > field exactly to the dedicated value to lock out a user completely, > or you set it to a variant to just disable password-based auth for > him. In FreeBSD the dedicated value is `*' (or, perhaps, leading > `*', as I observed in some communities), while any other character in > front of a password hash or after it will effectively deny any password > since our hashes are fixed-length, so they can't be matched by > a string of a different length. This sounds like a reasonable workaround - this way everyone gets a way to do what they want. Ceri -- It is not tinfoil, it is my new skin. I am a robot.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?200408301620.i7UGKP9V077390>