-Update the monkeysphere authorized_keys file. For each user ID in the
-user's authorized_user_ids file, gpg will be queried for keys
-associated with that user ID, querying a keyserver if specified. If a
-key is found, it will be converted to an ssh key, and any matching ssh
-keys will be removed from the user's authorized_keys file. If the
-found key is acceptable (see KEY ACCEPTABILITY), then the key will be
-updated and re-added to the authorized_keys file. If no gpg key is
-found for the user ID, then nothing is done. `a' may be used in place
-of `update-authorized_keys'.
-.TP
-.B gen-subkey KEYID
-Generate an `a` capable subkey. For the primary key with the
-specified key ID, generate a subkey with "authentication" capability
-that can be used for MonkeySphere transactions. `g' may be used in
-place of `gen-subkey'.
+Update the authorized_keys file for the user executing the command
+(see MONKEYSPHERE_AUTHORIZED_KEYS in ENVIRONMENT, below). First all
+monkeysphere keys are cleared from the authorized_keys file. Then, or
+each user ID in the user's authorized_user_ids file, 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
+.BR monkeysphere (7)),
+the key is added to the user's authorized_keys file.
+If a key is found but is unacceptable for the user ID, any matching
+keys are removed from the user's authorized_keys file. If no gpg key
+is found for the user ID, nothing is done. This subcommand will exit
+with a status of 0 if at least one acceptable key was found for a user
+ID, 1 if no matching keys were found at all, and 2 if matching keys
+were found but none were acceptable. `a' may be used in place of
+`update-authorized_keys'.
+.TP
+.B import-subkey FILE [KEYID]
+Import an existing ssh RSA key as an authentication subkey for a
+private key in your GnuPG keyring. KEYID is the key ID for the
+primary key for which the subkey with "authentication" capability will
+be imported. If no key ID is specified, but only one key exists in
+the secret keyring, that key will be used. `i' may be used in place
+of `import-subkey'.
+.TP
+.B gen-subkey [KEYID]
+Generate an authentication subkey for a private key in your GnuPG
+keyring. KEYID is the key ID for the primary key for which the subkey
+with "authentication" capability will be generated. If no key ID is
+specified, but only one key exists in the secret keyring, that key
+will be used. The length of the generated key can be specified with
+the `--length` or `-l` option. `g' may be used in place of
+`gen-subkey'.
+.TP
+.B ssh-proxycommand
+An ssh ProxyCommand that can be used to trigger a monkeysphere update
+of the ssh known_hosts file for a host that is being connected to with
+ssh. This works by updating the known_hosts file for the host first,
+before an attempted connection to the host is made. Once the
+known_hosts file has been updated, a TCP connection to the host is
+made by exec'ing netcat(1). Regular ssh communication is then done
+over this netcat TCP connection (see ProxyCommand in ssh_config(5) for
+more info).
+
+This command is meant to be run as the ssh "ProxyCommand". This can
+either be done by specifying the proxy command on the command line:
+
+.B ssh -o ProxyCommand="monkeysphere ssh-proxycommand %h %p" ...
+
+or by adding the following line to your ~/.ssh/config script:
+
+.B ProxyCommand monkeysphere ssh-proxycommand %h %p
+
+The script can easily be incorporated into other ProxyCommand scripts
+by calling it with the "--no-connect" option, i.e.:
+
+.B monkeysphere ssh-proxycommand --no-connect "$HOST" "$PORT"
+
+This will run everything except the final exec of netcat to make the
+TCP connection to the host. In this way this command can be added to
+another proxy command that does other stuff, and then makes the
+connection to the host itself.
+
+KEYSERVER CHECKING:
+The proxy command has a fairly nuanced policy for when keyservers are
+queried when processing a host. If the host userID is not found in
+either the user's keyring or in the known_hosts file, then the
+keyserver is queried for the host userID. If the host userID is found
+in the user's keyring, then the keyserver is not checked. This
+assumes that the keyring is kept up-to-date, in a cronjob or the like,
+so that revocations are properly handled. If the host userID is not
+found in the user's keyring, but the host is listed in the known_hosts
+file, then the keyserver is not checked. This last policy might
+change in the future, possibly by adding a deferred check, so that
+hosts that go from non-monkeysphere-enabled to monkeysphere-enabled
+will be properly checked.
+
+Setting the CHECK_KEYSERVER variable in the config file or the
+MONKEYSPHERE_CHECK_KEYSERVER environment variable to either `true' or
+`false' will override the keyserver-checking policy defined above and
+either always or never check the keyserver for host key updates.
+
+.TP
+.B subkey-to-ssh-agent [ssh-add arguments]
+Push all authentication-capable subkeys in your GnuPG secret keyring
+into your running ssh-agent. Additional arguments are passed through
+to
+.BR ssh-add (1).
+For example, to remove the authentication subkeys, pass an additional
+`-d' argument. To require confirmation on each use of the key, pass
+`-c'. `s' may be used in place of `subkey-to-ssh-agent'.