.\"	$OpenBSD: skeyinit.1,v 1.42 2022/02/06 00:29:03 jsg Exp $
.\"	$NetBSD: skeyinit.1,v 1.4 1995/07/07 22:24:09 jtc Exp $
.\"	@(#)skeyinit.1	1.1 	10/28/93
.\"
.Dd $Mdocdate: February 6 2022 $
.Dt SKEYINIT 1
.Os
.Sh NAME
.Nm skeyinit
.Nd change password or add user to S/Key authentication system
.Sh SYNOPSIS
.Nm skeyinit
.Bk -words
.Op Fl DErsx
.Op Fl a Ar auth-type
.Op Fl n Ar count
.Op Fl md5 | rmd160 | sha1
.Op Ar user
.Ek
.Sh DESCRIPTION
.Nm
initializes the system so you can use S/Key one-time passwords to log in.
The program will ask you to enter a secret passphrase which is used by
.Xr skey 1
to generate one-time passwords:
enter a phrase of several words in response.
After the S/Key database
has been updated you can log in using either your regular password
or using S/Key one-time passwords.
.Pp
.Nm
requires you to type a secret passphrase, so it should be used
only on a secure terminal.
For example, on the console of a
workstation or over an encrypted network session.
If you are using
.Nm
while logged in over an untrusted network, follow the instructions
given below with the
.Fl s
option.
.Pp
Before initializing an S/Key entry, the user must authenticate
using either a standard password or an S/Key challenge.
To use a one-time password for initial authentication,
.Ic skeyinit -a skey
can be used.
The user will then be presented with the standard
S/Key challenge and allowed to proceed if it is correct.
.Pp
.Nm
prints a sequence number and a one-time password.
This password can't be used to log in; one-time passwords should be
generated using
.Xr skey 1
first.
The one-time password printed by
.Nm
can be used to verify if the right passphrase has been given to
.Xr skey 1 .
The one-time password with the corresponding sequence number printed by
.Xr skey 1
should match the one printed by
.Nm .
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl a Ar auth-type
Before an S/Key entry can be initialised,
the user must authenticate themselves to the system.
This option allows the authentication type to be specified, such as
.Dq passwd
or
.Dq skey .
.It Fl D
Disables access to the S/Key database.
Only the superuser may use the
.Fl D
option.
.It Fl E
Enables access to the S/Key database.
Only the superuser may use the
.Fl E
option.
.It Fl md5 | rmd160 | sha1
Selects the hash algorithm:
MD5, RMD-160 (160-bit Ripe Message Digest),
or SHA1 (NIST Secure Hash Algorithm Revision 1).
.It Fl n Ar count
Start the
.Nm skey
sequence at
.Ar count
(default is 100).
.It Fl r
Removes the user's S/Key entry.
.It Fl s
Secure mode.
The user is expected to have already used a secure
machine to generate the first one-time password.
Without the
.Fl s
option the system will assume you are directly connected over secure
communications and prompt you for your secret passphrase.
The
.Fl s
option also allows one to set the seed and count for complete
control of the parameters.
.Pp
When the
.Fl s
option is specified,
.Nm
will try to authenticate the user via S/Key, instead of the default listed in
.Pa /etc/login.conf .
If a user has no entry in the S/Key database, an alternate authentication
type must be specified via the
.Fl a
option
(see above).
Entering a password or passphrase in plain text
defeats the purpose of using
.Dq secure
mode.
.Pp
You can use
.Ic skeyinit -s
in combination with the
.Nm skey
command to set the seed and count if you do not like the defaults.
To do this run
.Ic skeyinit -s
in one window and put in your count and seed, then run
.Xr skey 1
in another window to generate the correct 6 English words for that
count and seed.
You can then "cut-and-paste" or type the words into the
.Nm
window.
.It Fl x
Displays one-time passwords in hexadecimal instead of ASCII.
.It Ar user
The username to be changed/added.
By default the current user is operated on.
.El
.Sh FILES
.Bl -tag -width /etc/login.conf -compact
.It Pa /etc/login.conf
file containing authentication types
.It Pa /etc/skey
directory containing user entries for S/Key
.El
.Sh EXAMPLES
.Bd -literal
$ skeyinit
Password: \*(Ltenter your regular password here\*(Gt
[Updating user with md5]
Old seed: [md5] host12377
Enter new secret passphrase: \*(Lttype a new passphrase here\*(Gt
Again secret passphrase: \*(Ltagain\*(Gt
ID user skey is otp-md5 100 host12378
Next login password: CITE BREW IDLE CAIN ROD DOME
$ otp-md5 -n 3 100 host12378
Enter secret passphrase: \*(Lttype your passphrase here\*(Gt
98: WERE TUG EDDY GEAR GILL TEE
99: NEAR HA TILT FIN LONG SNOW
100: CITE BREW IDLE CAIN ROD DOME
.Ed
.Pp
The one-time password for the next login will have sequence number 99.
.Sh DIAGNOSTICS
.Bl -tag -compact -width "skey disabled"
.It "skey disabled"
.Pa /etc/skey
does not exist or is not accessible by the user.
The superuser may enable
.Nm
via the
.Fl E
flag.
.El
.Sh SEE ALSO
.Xr skey 1 ,
.Xr skeyaudit 1 ,
.Xr skeyinfo 1 ,
.Xr skey 5 ,
.Xr skeyprune 8
.Sh AUTHORS
.An Phil Karn
.An Neil M. Haller
.An John S. Walden
.An Scott Chasin
.An Todd Miller