shithub: purgatorio

ref: efd1615c5741a6898853fefc24b1cbcb734e5477
dir: /man/4/keyfs/

View raw version
.TH KEYFS 4
.SH NAME
keyfs \- encrypted key storage
.SH SYNOPSIS
.B auth/keyfs
[
.B -D
]
[
.BI -m " mountpoint"
] [
.BI -n " nvram"
] [
.I keyfile
]
.SH DESCRIPTION
.I Keyfs
serves a two-level name space for storing authentication data, specifically
the status and secrets of each user to whom
.IR logind (8)
can issue a certificate.
The data is stored in
.I keyfile
(default:
.BR /keydb/keys ),
encrypted by a master key using AES
(see
.IR keyring-crypt (2)).
.I Keyfs
should be started only on the machine acting as authentication server (signer),
before a listener is started for
.IR signer (8).
Note that
.I signer
and
.I keyfs
must share the name space.
Furthermore, no other application except the console should see that name space.
.PP
.I Keyfs
prompts for the master key, reads and decrypts
.IR keyfile ,
and serves files representing the contents at
.I mountpoint
in the name space (default:
.BR /mnt/keys ).
.PP
Each
.I user
in
.I keyfile
is represented by a directory
.IB mountpoint / user.
Each such directory has the following files:
.TF status
.TP
.B log
A count of the number of failed authentications.
Writing
.B bad
to the file increments the count; writing
.B good
resets it to 0.
When the count reaches some implementation-defined limit,
the account status is set to
.B disabled
(see the
.B status
file below).
.TP
.B expire
The time in seconds since the epoch when the account will expire,
or the text
.B never
if it has no expiration time.
The string
.B never
or a number can be written to the file to set a new expiry time.
.TP
.B secret
The secret (supposedly) known only to the user and the authentication service.
A secret is any sequence of bytes between 0 and 255 bytes long;
it is initially empty.
The length of the file returned by
.IR sys-stat (2)
is the length of the secret.
If the account has expired or is disabled, an attempt to read the file
will give an error.
.TP
.B status
The current status of the user's account, either
.B ok
or
.BR disabled .
Either string can be written to the file to change the state accordingly.
.PD
.PP
To add a new account, make a directory with that name in
.IR mountpoint .
It must not already exist.
To remove an account, remove the corresponding directory;
to rename an account, rename the directory.
.PP
All changes made via file system operations in
.I mountpoint
result in appropriate changes to
.IR keyfile .
.PD
.PP
If the
.B -n
option is given, instead of prompting for the master key,
.I keyfs
will read it from the file
.IR nvram .
Obviously that file should be well-protected from ordinary observers.
.PP
The
.B -D
option enables tracing of the file service protocol, for debugging.
.SH SOURCE
.B /appl/cmd/auth/keyfs.b
.SH SEE ALSO
.IR changelogin (8),
.IR logind (8),
.IR signer (8)