.\" $OpenBSD: skey.5,v 1.2 2003/01/23 08:58:47 jmc Exp $
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.\" Copyright (c) 2002 Todd C. Miller <Todd.Miller@courtesan.com>
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.Dd May 16, 2002
.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 EXAMPLES
Here is a sample
.Pa /etc/skey
file for root:
.Bd -literal -offset indent
root
md5
99
obsd36521
1f4359a3764b675d
.Ed
.Sh FILES
.Bl -tag -width /etc/skey -compact
.It Pa /etc/skey
.El
.Sh SEE ALSO
.Xr skey 1 ,
.Xr skeyinit 1 ,
.Xr skey 3