.\" $OpenBSD: skey.5,v 1.6 2007/05/31 19:19:37 jmc Exp $
.\"
.\" Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" Sponsored in part by the Defense Advanced Research Projects
.\" Agency (DARPA) and Air Force Research Laboratory, Air Force
.\" Materiel Command, USAF, under agreement number F39502-99-1-0512.
.\"
.Dd $Mdocdate: May 31 2007 $
.Dt SKEY 5
.Os
.Sh NAME
.Nm skey
.Nd one-time password user database
.Sh DESCRIPTION
The
.Pa /etc/skey
directory contains user records for the S/Key one-time password authentication
system.
.Pp
Records take the form of files within
.Pa /etc/skey
where each file is named for the user whose record it contains.
For example,
.Pa /etc/skey/root
would hold root's S/Key record.
.Pp
The mode for
.Pa /etc/skey
should be 01730 and it should be owned by root and group auth.
Individual records within
.Pa /etc/skey
should be owned by the user they describe and be mode 0600.
To access S/Key records, a process must run as group auth.
.Pp
Each record consists of five lines:
.Bl -enum
.It
The name of the user the record describes.
This should be the same as the name of the file.
.It
The hash type used for this entry;
one of md4, md5, sha1, or rmd160.
The default is md5.
.It
The sequence number.
This is a decimal number between one and one thousand.
Each time the user authenticates via S/Key this number is decremented by one.
.It
A seed used along with the sequence number and the six S/Key words to
compute the value.
.It
The value expected from the crunching of the user's seed, sequence number
and the six S/Key words.
When the result matches this value, authentication is considered to have
been successful.
.El
.Sh FILES
.Bl -tag -width /etc/skey -compact
.It Pa /etc/skey
.El
.Sh EXAMPLES
Here is a sample
.Pa /etc/skey
file for root:
.Bd -literal -offset indent
root
md5
99
obsd36521
1f4359a3764b675d
.Ed
.Sh SEE ALSO
.Xr skey 1 ,
.Xr skeyinit 1 ,
.Xr skey 3