path: root/man/man8/monkeysphere-server.8

.TH MONKEYSPHERE-SERVER "8" "June 2008" "monkeysphere" "User Commands"

.SH NAME

monkeysphere-server \- Monkeysphere server admin user interface

.SH SYNOPSIS

.B monkeysphere-server \fIsubcommand\fP [\fIargs\fP]

.SH DESCRIPTION

\fBMonkeysphere\fP is a framework to leverage the OpenPGP web of trust
for OpenSSH authentication.  OpenPGP keys are tracked via GnuPG, and
added to the authorized_keys and known_hosts files used by OpenSSH for
connection authentication.

\fBmonkeysphere-server\fP is the Monkeysphere server admin utility.

.SH SUBCOMMANDS

\fBmonkeysphere-server\fP takes various subcommands:
.TP
.B update-users [ACCOUNT]...
Rebuild the monkeysphere-controlled authorized_keys files.  For each
specified account, the user ID's listed in the account's
authorized_user_ids file are processed.  For each user ID, gpg will be
queried for keys associated with that user ID, optionally querying a
keyserver.  If an acceptable key is found (see KEY ACCEPTABILITY in
monkeysphere(5)), the key is added to the account's
monkeysphere-controlled authorized_keys file.  If the
RAW_AUTHORIZED_KEYS variable is set, then a separate authorized_keys
file (usually ~USER/.ssh/authorized_keys) is appended to the
monkeysphere-controlled authorized_keys file.  If no accounts are
specified, then all accounts on the system are processed.  `u' may be
used in place of `update-users'.
.TP
.B gen-key [HOSTNAME]
Generate a OpenPGP key for the host.  If HOSTNAME is not specified,
then the system fully-qualified domain name will be user.  An
alternate key bit length can be specified with the `-l' or `--length'
option (default 2048).  An expiration length can be specified with the
`-e' or `--expire' option (prompt otherwise).  The expiration format
is the same as that of \fBextend-key\fP, below.  A key revoker
fingerprint can be specified with the `-r' or `--revoker' option.  `g'
may be used in place of `gen-key'.
.TP
.B extend-key EXPIRE
Extend the validity of the OpenPGP key for the host until EXPIRE from
the present.  If EXPIRE is not specified, then the user will be
prompted for the extension term.  Expiration is specified like GnuPG
does:
.nf
         0 = key does not expire
      <n>  = key expires in n days
      <n>w = key expires in n weeks
      <n>m = key expires in n months
      <n>y = key expires in n years
.fi
`e' may be used in place of `extend-key'.
.TP
.B add-hostname HOSTNAME
Add a hostname user ID to the server host key.  `n+' may be used in
place of `add-hostname'.
.TP
.B revoke-hostname HOSTNAME
Revoke a hostname user ID from the server host key.  `n-' may be used
in place of `revoke-hostname'.
.TP
.B show-key
Output gpg information about host's OpenPGP key.  `s' may be used in
place of `show-key'.
.TP
.B publish-key
Publish the host's OpenPGP key to the keyserver.  `p' may be used in
place of `publish-key'.
.TP
.B diagnostics
Review the state of the server with respect to the MonkeySphere in
general and report on suggested changes.  Among other checks, this
includes making sure there is a valid host key, that the key is
published, that the sshd configuration points to the right place, and
that there are at least some valid identity certifiers.  `d' may be
used in place of `diagnostics'.
.TP
.B add-identity-certifier KEYID
Instruct system to trust user identity certifications made by KEYID.
Using the `-n' or `--domain' option allows you to indicate that you
only trust the given KEYID to make identifications within a specific
domain (e.g. "trust KEYID to certify user identities within the
@example.org domain").  A certifier trust level can be specified with
the `-t' or `--trust' option (possible values are `marginal' and
`full' (default is `full')).  A certifier trust depth can be specified
with the `-d' or `--depth' option (default is 1).  `c+' may be used in
place of `add-identity-certifier'.
.TP
.B remove-identity-certifier KEYID
Instruct system to ignore user identity certifications made by KEYID.
`c-' may be used in place of `remove-identity-certifier'.
.TP
.B list-identity-certifiers
List key IDs trusted by the system to certify user identities.  `c'
may be used in place of `list-identity-certifiers'.
.TP
.B gpg-authentication-cmd
Execute a gpg command on the gnupg-authentication keyring as the
monkeysphere user.  This takes a single command (multiple gpg
arguments need to be quoted).  Use this command with caution, as
modifying the gnupg-authentication keyring can affect ssh user
authentication.
.TP
.B help
Output a brief usage summary.  `h' or `?' may be used in place of
`help'.

.SH SETUP

In order to start using the monkeysphere, you must first generate an
OpenPGP key for the server and convert that key to an ssh key that can
be used by ssh for host authentication.  This can be done with the
\fBgen-key\fP subcommand:

$ monkeysphere-server gen-key

To enable host verification via the monkeysphere, you must then
publish the host's key to the Web of Trust using the \fBpublish-key\fP
command to push the key to a keyserver.  You must also modify the
sshd_config on the server to tell sshd where the new server host key
is located:

HostKey /var/lib/monkeysphere/ssh_host_rsa_key

In order for users logging into the system to be able to verify the
host via the monkeysphere, at least one person (e.g. a server admin)
will need to sign the host's key.  This is done using standard key
signing techniquies, usually by pulling the key from the keyserver,
signing the key, and re-publishing the signature.  Once that is done,
users logging into the host will be able to certify the host's key via
the signature of the host admin.

If the server will also handle user authentication through
monkeysphere-generated authorized_keys files, the server must be told
which keys will act as user certifiers.  This is done with the
\fBadd-certifier\fP command:

$ monkeysphere-server add-certifier KEYID

where KEYID is the key ID of the server admin, or whoever's signature
will be certifying users to the system.  Certifiers can be removed
with the \fBremove-certifier\fP command, and listed with the
\fBlist-certifiers\fP command.

Remote user's will then be granted access to a local user account
based on the appropriately signed and valid keys associated with user
IDs listed in the authorized_user_ids file of the local user.  By
default, the authorized_user_ids file for local users is found in
~/.config/monkeysphere/authorized_user_ids.  This can be changed in
the monkeysphere-server.conf file.

The \fBupdate-users\fP command can then be used to generate
authorized_keys file for local users based on the authorized user IDs
listed in the various local user's authorized_user_ids file:

$ monkeysphere-server update-users USER

Not specifying a specific user will cause all users on the system to
updated.  sshd can then use these monkeysphere generated
authorized_keys files to grant access to user accounts for remote
users.  You must also tell sshd to look at the monkeysphere-generated
authorized_keys file for user authentication by setting the following
in the sshd_config:

AuthorizedKeysFile /var/lib/monkeysphere/authorized_keys/%u

It is recommended to add "monkeysphere-server update-users" to a
system crontab, so that user keys are kept up-to-date, and key
revocations and expirations can be processed in a timely manor.

.SH ENVIRONMENT

The following environment variables will override those specified in
the monkeysphere-server.conf configuration file (defaults in
parentheses):
.TP
MONKEYSPHERE_LOG_LEVEL
Set the log level.  Can be SILENT, ERROR, INFO, VERBOSE, DEBUG, in
increasing order of verbosity.
.TP
MONKEYSPHERE_KEYSERVER
OpenPGP keyserver to use (subkeys.pgp.net).
.TP
MONKEYSPHERE_AUTHORIZED_USER_IDS
Path to user authorized_user_ids file
(%h/.config/monkeysphere/authorized_user_ids).
.TP
MONKEYSPHERE_RAW_AUTHORIZED_KEYS
Path to user-controlled authorized_keys file.  `-' means not to add
user-controlled file (%h/.ssh/authorized_keys).
.TP
MONKEYSPHERE_MONKEYSPHERE_USER
User to control authentication keychain (monkeysphere).

.SH FILES

.TP
/etc/monkeysphere/monkeysphere-server.conf
System monkeysphere-server config file.
.TP
/etc/monkeysphere/monkeysphere.conf
System-wide monkeysphere config file.
.TP
/var/lib/monkeysphere/authorized_keys/USER
Monkeysphere-generated user authorized_keys files.
.TP
/var/lib/monkeysphere/ssh_host_rsa_key
Copy of the host's private key in ssh format, suitable for use by
sshd.
.TP
/var/lib/monkeysphere/gnupg-host
Monkeysphere host GNUPG home directory.
.TP
/var/lib/monkeysphere/gnupg-authentication
Monkeysphere authentication GNUPG home directory.

.SH AUTHOR

Written by Jameson Rollins <jrollins@fifthhorseman.net>, Daniel Kahn
Gillmor <dkg@fifthhorseman.net>

.SH SEE ALSO

.BR monkeysphere (1),
.BR monkeysphere (5),
.BR gpg (1),
.BR ssh (1)