Ubuntu Manpage: monkeysphere - Monkeysphere client user interface

NAME

       monkeysphere - Monkeysphere client user interface

SYNOPSIS

       monkeysphere subcommand [args]

DESCRIPTION

       Monkeysphere  is  a  framework  to  leverage  the  OpenPGP  web  of  trust  for OpenSSH and TLS key-based
       authentication.  OpenPGP keys are tracked via GnuPG, and added to  the  authorized_keys  and  known_hosts
       files used by OpenSSH for connection authentication.  Monkeysphere can also be used by a validation agent
       to validate TLS connections (e.g. https).

       monkeysphere is the Monkeysphere client utility.

SUBCOMMANDS

monkeysphere takes various subcommands:

update-known_hosts [HOST]...
Update the known_hosts file. For each specified host, gpg will be queried for a key associated
with the host URI (see HOST IDENTIFICATION in monkeysphere(7)), optionally querying a keyserver.
If an acceptable key is found for the host (see KEY ACCEPTABILITY in monkeysphere(7)), the key is
added to the user's known_hosts file. If a key is found but is unacceptable for the host, any
matching keys are removed from the user's known_hosts file. If no gpg key is found for the host,
nothing is done. If no hosts are specified, all hosts listed in the known_hosts file will be
processed. This subcommand will exit with a status of 0 if at least one acceptable key was found
for a specified host, 1 if no matching keys were found at all, and 2 if matching keys were found
but none were acceptable. `k' may be used in place of `update-known_hosts'.

update-authorized_keys
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, for 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 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'.

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'.

ssh-proxycommand [--no-connect] HOST [PORT]
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:

ssh -o ProxyCommand="monkeysphere ssh-proxycommand %h %p" ...

or by adding the following line to your ~/.ssh/config script:

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.:

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. For example, in ~/.ssh/config:

ProxyCommand sh -c 'monkeysphere ssh-proxycommand --no-connect %h %p ; ssh -W %h:%p
jumphost.example.net'

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.

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 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'. The MONKEYSPHERE_SUBKEYS_FOR_AGENT environment can be used to specify the full fingerprints
of specific keys to add to the agent (space separated), instead of adding them all. `s' may be
used in place of `subkey-to-ssh-agent'.

keys-for-userid USERID
Output to stdout all acceptable keys for a given user ID. `u' may be used in place of
`keys-for-userid'.

sshfprs-for-userid USERID
Output the ssh fingerprints of acceptable keys for a given user ID.

version
Show the monkeysphere version number. `v' may be used in place of `version'.

help Output a brief usage summary. `h' or `?' may be used in place of `help'.

ENVIRONMENT

       The following environment variables will override those specified in the monkeysphere.conf  configuration
       file (defaults in parentheses):

       MONKEYSPHERE_LOG_LEVEL
              Set  the log level.  Can be SILENT, ERROR, INFO, VERBOSE, DEBUG, in increasing order of verbosity.
              (INFO)

       MONKEYSPHERE_GNUPGHOME, GNUPGHOME
              GnuPG home directory. (~/.gnupg)

       MONKEYSPHERE_KEYSERVER
              OpenPGP keyserver to use. (pool.sks-keyservers.net)

       MONKEYSPHERE_CHECK_KEYSERVER
              Whether or not to check keyserver when making gpg queries. (true)

       MONKEYSPHERE_KNOWN_HOSTS
              Path to ssh known_hosts file. (~/.ssh/known_hosts)

       MONKEYSPHERE_HASH_KNOWN_HOSTS
              Whether or not to hash to the known_hosts file entries. (false)

       MONKEYSPHERE_AUTHORIZED_KEYS
              Path to ssh authorized_keys file. (~/.ssh/authorized_keys)

       MONKEYSPHERE_PROMPT
              If set to `false', never prompt the user for confirmation. (true)

       MONKEYSPHERE_STRICT_MODES
              If  set  to  `false',  ignore  too-loose  permissions   on   known_hosts,   authorized_keys,   and
              authorized_user_ids  files.  NOTE: setting this to false may expose you to abuse by other users on
              the system. (true)

       MONKEYSPHERE_SUBKEYS_FOR_AGENT
              A space-separated list of authentication-capable subkeys to add to the ssh agent  with  subkey-to-
              ssh-agent.

FILES

       ~/.monkeysphere/monkeysphere.conf
              User monkeysphere config file.

       /etc/monkeysphere/monkeysphere.conf
              System-wide monkeysphere config file.

       ~/.monkeysphere/authorized_user_ids
              A  list  of  OpenPGP  user  IDs,  one  per  line.   OpenPGP  keys with an exactly-matching User ID
              (calculated valid by the designated identity  certifiers),  will  have  any  valid  authorization-
              capable keys or subkeys added to the given user's authorized_keys file.

AUTHOR

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