.TH KEYFS 4
.SH NAME
keyfs, warning \- authentication database files
.SH SYNOPSIS
.B auth/keyfs
[
.B -p
]
[
.B -w
.RB [ np ]
]
[
.BI -m mntpt
]
[
.I keyfile
]
.PP
.B auth/warning
[
.B -n
]
[
.B -p
]
.SH DESCRIPTION
.I Keyfs
serves a two-level file tree for manipulating authentication information.
It runs on the machine providing authentication service for the local
Plan 9 network, which may be a dedicated authentication server or
a CPU server.
The programs described in
.IR auth (8)
use
.I keyfs
as their interface to the authentication database.
.PP
.I Keyfs
reads and decrypts file
.I keyfile
(default
.BR /adm/keys )
using the DES key,
which is by default read from
.B #r/nvram
(see
.IR rtc (3)).
With option
.BR -p ,
.I keyfs
prompts for a password from which the key is derived.
.I Keyfile
holds a 41-byte record for each user in the database.
Each record is encrypted separately
and contains the user's name,
DES key,
status,
host status,
and expiration date.
The name is a
null-terminated
.SM UTF
string
.B NAMELEN
bytes long.
The status is a byte containing
binary 0 if the account is enabled,
1 if it is disabled.
Host status is a byte containing
binary 1 if the user is a host,
0 otherwise.
The expiration date is four-byte little-endian integer
which represents the time in seconds since the epoch
(see
.IR date (1))
at which the account will expire.
If any changes are made to the database that affect the information stored in
.IR keyfile ,
a new version of the file is written.
.PP
There are two authentication databases,
one for Plan 9 user information,
and one for SecureNet user information.
A user need not be installed in both databases
but must be installed in the Plan 9 database to connect to a Plan 9 server.
.PP
.I Keyfs
serves an interpretation of the
.I keyfile
in the file tree rooted at
.I mntpt
(default
.BR /mnt/keys ).
Each user
.I user
in
.I keyfile
is represented as the directory
.IR mntpt / user .
.PP
Making a new directory in
.I mntpt
creates a new user entry in the database.
Removing a directory removes the user entry,
and renaming it changes the name in the entry.
Such changes are reflected immediately in
.IR keyfile .
.I Keyfs
does not allow duplicate names when creating or renaming user entries.
.PP
All files in the user directories except for
.B key
contain
.SM UTF
strings with a trailing newline when read,
and should be written as
.SM UTF
strings with or without a trailing newline.
.B Key
contains the
.BR DESKEYLEN -byte
encryption key for the user.
.PP
The following files appear in the user directories.
.TF expire
.TP
.B key
The authentication key for the user.
If the user's account is disabled or expired,
reading this file returns an error.
Writing
.I key
changes the key in the database.
.TP
.B log
The number of consecutive failed authentication attempts for the user.
Writing the string
.B bad
increments this number; writing
.B good
resets it to 0.
This number is not stored in
.IR keyfile ,
and is initialized to 0 when
.I keyfs
starts.
If the number reaches a multiple of ten,
the account gets into purgatory
for as many seconds as the 
number is.
When in purgatory, the
.BR key
file can't be read, the number increases
further in case of failed authentication attempts.
.TP
.B status
The current status of the account, either
.B ok
or
.BR disabled .
Writing
.B ok
enables the account;
writing
.B disabled
disables it.
.TP
.B expire
The expiration time for the account.
When read, it contains either the string
.B never
or the time in seconds since the epoch
that the account will expire.
When written with strings of the same form,
it sets the expiration date for the user.
If the expiration date is reached,
the account is not disabled,
but
.I key
cannot be read without an error.
.PD
.PP
If the
.B -w
option is on,
.I keyfs
runs the command
.I warning
once every 24 hours to mail people about expiring keys.
Warnings are sent 14 days and 7 days prior to expiration.
The argument to
.BR -w ,
either
.B p
or
.BR n ,
is passed to
.I warning
to restrict the warnings to
the Plan 9 or SecureNet database.
The default for
.I keyfs
is not to call
.I warning
at all;
.I warning's
own default is to warn about both.
The files
.B /adm/netkeys.who
and
.B /adm/keys.who
are used to find the mail addresses to send to.
The first word on each line identifies
a user.
Any subsequent strings on the line delimited '<' and '>' are considered mail
addresses to send warnings to.
If multiple lines match a user, the last in the file is used.
.B Changeuser
(see
.IR auth (8))
adds lines to these files.
.SH FILES
.TF /adm/netkeys.who
.TP
.B /adm/keys
Encrypted key file for the Plan 9 database.
.TP
.B /adm/netkeys
Encrypted key file for the SecureNet database.
.TP
.B /adm/keys.who
List of users in the Plan 9 database.
.TP
.B /adm/netkeys.who
List of users in  the SecureNet database.
.TP
.B #r/nvram
The non-volatile RAM on the server, which holds the key used
to decrypt key files.
.SH SOURCE
.B /sys/src/cmd/auth/keyfs.c
.br
.B /sys/src/cmd/auth/warning.c
.SH "SEE ALSO"
.IR authsrv (6),
.IR namespace (6),
.IR auth (8)