Name

mandos-clients.conf — Configuration file for the Mandos server

Synopsis

/etc/mandos/clients.conf

DESCRIPTION

The file /etc/mandos/clients.conf is a configuration file for mandos(8), read by it at startup. The file needs to list all clients that should be able to use the service. All clients listed will be regarded as valid, even if a client was declared invalid in a previous run of the server.

The format starts with a [section header] which is either [DEFAULT] or [client name]. The client name can be anything, and is not tied to a host name. Following the section header is any number of “option=value” entries, with continuations in the style of RFC 822. “option: value” is also accepted. Note that leading whitespace is removed from values. Values can contain format strings which refer to other values in the same section, or values in the “DEFAULT” section (see the section called “EXPANSION”). Lines beginning with “#” or “;” are ignored and may be used to provide comments.

OPTIONS

Note: all option values are subject to start time expansion, see the section called “EXPANSION”.

Unknown options are ignored. The used options are as follows:

timeout = TIME

This option is optional.

The timeout is how long the server will wait (for either a successful checker run or a client receiving its secret) until a client is considered invalid - that is, ineligible to get the data this server holds. By default Mandos will use 1 hour.

The TIME is specified as a space-separated number of values, each of which is a number and a one-character suffix. The suffix must be one of “d”, “s”, “m”, “h”, and “w” for days, seconds, minutes, hours, and weeks, respectively. The values are added together to give the total time value, so all of “330s”, “110s 110s 110s”, and “5m 30s” will give a value of five minutes and thirty seconds.

interval = TIME

This option is optional.

How often to run the checker to confirm that a client is still up. Note: a new checker will not be started if an old one is still running. The server will wait for a checker to complete until the above “timeout” occurs, at which time the client will be marked invalid, and any running checker killed. The default interval is 5 minutes.

The format of TIME is the same as for timeout above.

checker = COMMAND

This option is optional.

This option allows you to override the default shell command that the server will use to check if the client is still up. Any output of the command will be ignored, only the exit code is checked: If the exit code of the command is zero, the client is considered up. The command will be run using “/bin/sh -c”, so PATH will be searched. The default value for the checker command is “fping -q -- %%(host)s”.

In addition to normal start time expansion, this option will also be subject to runtime expansion; see the section called “EXPANSION”.

fingerprint = HEXSTRING

This option is required.

This option sets the OpenPGP fingerprint that identifies the public key that clients authenticate themselves with through TLS. The string needs to be in hexidecimal form, but spaces or upper/lower case are not significant.

secret = BASE64_ENCODED_DATA

If this option is not specified, the secfile option is required to be present.

If present, this option must be set to a string of base64-encoded binary data. It will be decoded and sent to the client matching the above fingerprint. This should, of course, be OpenPGP encrypted data, decryptable only by the client. The program mandos-keygen(8) can, using its --password option, be used to generate this, if desired.

Note: this value of this option will probably be very long. A useful feature to avoid having unreadably-long lines is that a line beginning with white space adds to the value of the previous line, RFC 822-style.

secfile = FILENAME

This option is only used if secret is not specified, in which case this option is required.

Similar to the secret, except the secret data is in an external file. The contents of the file should not be base64-encoded, but will be sent to clients verbatim.

File names of the form ~user/foo/bar and $ENVVAR/foo/bar are supported.

host = STRING

This option is optional, but highly recommended unless the checker option is modified to a non-standard value without “%%(host)s” in it.

Host name for this client. This is not used by the server directly, but can be, and is by default, used by the checker. See the checker option.

EXPANSION

There are two forms of expansion: Start time expansion and runtime expansion.

START TIME EXPANSION

Any string in an option value of the form “%(foo)s” will be replaced by the value of the option foo either in the same section, or, if it does not exist there, the [DEFAULT] section. This is done at start time, when the configuration file is read.

Note that this means that, in order to include an actual percent character (“%”) in an option value, two percent characters in a row (“%%”) must be entered.

RUNTIME EXPANSION

This is currently only done for the checker option.

Any string in an option value of the form “%%(foo)s” will be replaced by the value of the attribute foo of the internal “Client” object. See the source code for details, and let the authors know of any attributes that are useful so they may be preserved to any new versions of this software.

Note that this means that, in order to include an actual percent character (“%”) in a checker option, four percent characters in a row (“%%%%”) must be entered. Also, a bad format here will lead to an immediate but silent run-time fatal exit; debug mode is needed to expose an error of this kind.

FILES

The file described here is /etc/mandos/clients.conf

BUGS

The format for specifying times for timeout and interval is not very good.

The difference between %%(foo)s and %(foo)s is obscure.

EXAMPLE

[DEFAULT]
timeout = 1h
interval = 5m
checker = fping -q -- %%(host)s

# Client "foo"
[foo]
fingerprint =  7788 2722 5BA7 DE53 9C5A  7CFA 59CF F7CD BD9A 5920
secret =
        hQIOA6QdEjBs2L/HEAf/TCyrDe5Xnm9esa+Pb/vWF9CUqfn4srzVgSu234
        REJMVv7lBSrPE2132Lmd2gqF1HeLKDJRSVxJpt6xoWOChGHg+TMyXDxK+N
        Xl89vGvdU1XfhKkVm9MDLOgT5ECDPysDGHFPDhqHOSu3Kaw2DWMV/iH9vz
        3Z20erVNbdcvyBnuojcoWO/6yfB5EQO0BXp7kcyy00USA3CjD5FGZdoQGI
        Tb8A/ar0tVA5crSQmaSotm6KmNLhrFnZ5BxX+TiE+eTUTqSloWRY6VAvqW
        QHC7OASxK5E6RXPBuFH5IohUA2Qbk5AHt99pYvsIPX88j2rWauOokoiKZo
        t/9leJ8VxO5l3wf/U64IH8bkPIoWmWZfd/nqh4uwGNbCgKMyT+AnvH7kMJ
        3i7DivfWl2mKLV0PyPHUNva0VQxX6yYjcOhj1R6fCr/at8/NSLe2OhLchz
        dC+Ls9h+kvJXgF8Sisv+Wk/1RadPLFmraRlqvJwt6Ww21LpiXqXHV2mIgq
        WnR98YgSvUi3TJHrUQiNc9YyBzuRo0AjgG2C9qiE3FM+Y28+iQ/sR3+bFs
        zYuZKVTObqiIslwXu7imO0cvvFRgJF/6u3HNFQ4LUTGhiM3FQmC6NNlF3/
        vJM2hwRDMcJqDd54Twx90Wh+tYz0z7QMsK4ANXWHHWHR0JchnLWmenzbtW
        5MHdW9AYsNJZAQSOpirE4Xi31CSlWAi9KV+cUCmWF5zOFy1x23P6PjdaRm
        4T2zw4dxS5NswXWU0sVEXxjs6PYxuIiCTL7vdpx8QjBkrPWDrAbcMyBr2O
        QlnHIvPzEArRQLo=
host = foo.example.org
interval = 1m

# Client "bar"
[bar]
fingerprint = 3e393aeaefb84c7e89e2f547b3a107558fca3a27
secfile = /etc/mandos/bar-secret
timeout = 15m

SEE ALSO

mandos-keygen(8), mandos.conf(5), mandos(8)