Ubuntu Manpage: dirmngr - CRL and OCSP daemon

Provided by: dirmngr_2.1.11-6ubuntu2.1_amd64

NAME

       dirmngr - CRL and OCSP daemon

SYNOPSIS

       dirmngr [options] command [args]

DESCRIPTION

       Since  version  2.1  of  GnuPG, dirmngr takes care of accessing the OpenPGP keyservers.  As with previous
       versions it is also used as a server for managing and downloading certificate revocation lists (CRLs) for
       X.509 certificates, downloading X.509 certificates, and providing access to OCSP providers.   Dirmngr  is
       invoked internally by gpg, gpgsm, or via the gpg-connect-agent tool.

       For  historical  reasons  it  is  also  possible  to  start  dirmngr in a system daemon mode which uses a
       different directory layout.  However, this mode is deprecated and may eventually be removed.

COMMANDS

Commands are not distinguished from options except for the fact that only one command is allowed.

--version
Print the program version and licensing information. Note that you cannot abbreviate this
command.

--help, -h
Print a usage message summarizing the most useful command-line options. Not that you cannot
abbreviate this command.

--dump-options
Print a list of all available options and commands. Note that you cannot abbreviate this command.

--server
Run in server mode and wait for commands on the stdin. The default mode is to create a socket and
listen for commands there. This is only used for testing.

--daemon
Run in background daemon mode and listen for commands on a socket. Note that this also changes
the default home directory and enables the internal certificate validation code. This mode is
deprecated.

--list-crls
List the contents of the CRL cache on stdout. This is probably only useful for debugging purposes.

--load-crl file
This command requires a filename as additional argument, and it will make Dirmngr try to import
the CRL in file into it's cache. Note, that this is only possible if Dirmngr is able to retrieve
the CA's certificate directly by its own means. In general it is better to use gpgsm's --call-
dirmngr loadcrl filename command so that gpgsm can help dirmngr.

--fetch-crl url
This command requires an URL as additional argument, and it will make dirmngr try to retrieve an
import the CRL from that url into it's cache. This is mainly useful for debugging purposes. The
dirmngr-client provides the same feature for a running dirmngr.

--shutdown
This commands shuts down an running instance of Dirmngr. This command has currently no effect.

--flush
This command removes all CRLs from Dirmngr's cache. Client requests will thus trigger reading of
fresh CRLs.

OPTIONS

--options file
Reads configuration from file instead of from the default per-user configuration file. The
default configuration file is named ‘dirmngr.conf’ and expected in the home directory.

--homedir dir
Set the name of the home directory to dir. This option is only effective when used on the command
line. The default depends on the running mode:

With --daemon given on the commandline
the directory named ‘/etc/gnupg2’ is used for configuration files and ‘/var/cache/gnupg2’
for cached CRLs.

Without --daemon given on the commandline
the directory named ‘.gnupg’ directly below the home directory of the user unless the
environment variable GNUPGHOME has been set in which case its value will be used. All kind
of data is stored below this directory.

-v

--verbose
Outputs additional information while running. You can increase the verbosity by giving several
verbose commands to dirmngr, such as -vv.

--log-file file
Append all logging output to file. This is very helpful in seeing what the agent actually does.

--debug-level level
Select the debug level for investigating problems. level may be a numeric value or by a keyword:

none No debugging at all. A value of less than 1 may be used instead of the keyword.

basic Some basic debug messages. A value between 1 and 2 may be used instead of the keyword.

advanced
More verbose debug messages. A value between 3 and 5 may be used instead of the keyword.

expert Even more detailed messages. A value between 6 and 8 may be used instead of the keyword.

guru All of the debug messages you can get. A value greater than 8 may be used instead of the
keyword. The creation of hash tracing files is only enabled if the keyword is used.

How these messages are mapped to the actual debugging flags is not specified and may change with newer
releases of this program. They are however carefully selected to best aid in debugging.

--debug flags
This option is only useful for debugging and the behaviour may change at any time without notice.
FLAGS are bit encoded and may be given in usual C-Syntax.

--debug-all
Same as --debug=0xffffffff

--gnutls-debug level
Enable debugging of GNUTLS at level.

--debug-wait n
When running in server mode, wait n seconds before entering the actual processing loop and print
the pid. This gives time to attach a debugger.

-s

--sh

-c

--csh Format the info output in daemon mode for use with the standard Bourne shell respective the C-
shell . The default ist to guess it based on the environment variable SHELL which is in almost all
cases sufficient.

--force
Enabling this option forces loading of expired CRLs; this is only useful for debugging.

--use-tor
This option switches Dirmngr and thus GnuPG into ``Tor mode'' to route all network access via Tor
(an anonymity network). WARNING: As of now this still leaks the DNS queries; e.g. to lookup the
hosts in a keyserver pool. Certain other features are disabled if this mode is active.

--keyserver name
Use name as your keyserver. This is the server that gpg communicates with to receive keys, send
keys, and search for keys. The format of the name is a URI: `scheme:[//]keyservername[:port]' The
scheme is the type of keyserver: "hkp" for the HTTP (or compatible) keyservers, "ldap" for the
LDAP keyservers, or "mailto" for the Graff email keyserver. Note that your particular installation
of GnuPG may have other keyserver types available as well. Keyserver schemes are case-insensitive.
After the keyserver name, optional keyserver configuration options may be provided. These are the
same as the --keyserver-options of gpg, but apply only to this particular keyserver.

Most keyservers synchronize with each other, so there is generally no need to send keys to more
than one server. The keyserver hkp://keys.gnupg.net uses round robin DNS to give a different
keyserver each time you use it.

If exactly two keyservers are configured and only one is a Tor hidden service (.onion), Dirmngr
selects the keyserver to use depending on whether Tor is locally running or not. The check for a
running Tor is done for each new connection.

--nameserver ipaddr
In ``Tor mode'' Dirmngr uses a public resolver via Tor to resolve DNS names. If the default
public resolver, which is 8.8.8.8, shall not be used a different one can be given using this
option. Note that a numerical IP address must be given (IPv6 or IPv4) and that no error checking
is done for ipaddr. DNS queries in Tor mode do only work if GnuPG as been build with ADNS
support.

--disable-ldap
Entirely disables the use of LDAP.

--disable-http
Entirely disables the use of HTTP.

--ignore-http-dp
When looking for the location of a CRL, the to be tested certificate usually contains so called
CRL Distribution Point (DP) entries which are URLs describing the way to access the CRL. The
first found DP entry is used. With this option all entries using the HTTP scheme are ignored when
looking for a suitable DP.

--ignore-ldap-dp
This is similar to --ignore-http-dp but ignores entries using the LDAP scheme. Both options may
be combined resulting in ignoring DPs entirely.

--ignore-ocsp-service-url
Ignore all OCSP URLs contained in the certificate. The effect is to force the use of the default
responder.

--honor-http-proxy
If the environment variable ‘http_proxy’ has been set, use its value to access HTTP servers.

--http-proxy host[:port]
Use host and port to access HTTP servers. The use of this option overrides the environment
variable ‘http_proxy’ regardless whether --honor-http-proxy has been set.

--ldap-proxy host[:port]
Use host and port to connect to LDAP servers. If port is ommitted, port 389 (standard LDAP port)
is used. This overrides any specified host and port part in a LDAP URL and will also be used if
host and port have been ommitted from the URL.

--only-ldap-proxy
Never use anything else but the LDAP "proxy" as configured with --ldap-proxy. Usually dirmngr
tries to use other configured LDAP server if the connection using the "proxy" failed.

--ldapserverlist-file file
Read the list of LDAP servers to consult for CRLs and certificates from file instead of the
default per-user ldap server list file. The default value for file is ‘dirmngr_ldapservers.conf’
or ‘ldapservers.conf’ when running in --daemon mode.

This server list file contains one LDAP server per line in the format

hostname:port:username:password:base_dn

Lines starting with a '#' are comments.

Note that as usual all strings entered are expected to be UTF-8 encoded. Obviously this will lead
to problems if the password has orginally been encoded as Latin-1. There is no other solution
here than to put such a password in the binary encoding into the file (i.e. non-ascii characters
won't show up readable). ([The gpgconf tool might be helpful for frontends as it allows to edit
this configuration file using percent escaped strings.])

--ldaptimeout secs
Specify the number of seconds to wait for an LDAP query before timing out. The default is
currently 100 seconds. 0 will never timeout.

--add-servers
This options makes dirmngr add any servers it discovers when validating certificates against CRLs
to the internal list of servers to consult for certificates and CRLs.

This options is useful when trying to validate a certificate that has a CRL distribution point
that points to a server that is not already listed in the ldapserverlist. Dirmngr will always go
to this server and try to download the CRL, but chances are high that the certificate used to sign
the CRL is located on the same server. So if dirmngr doesn't add that new server to list, it will
often not be able to verify the signature of the CRL unless the --add-servers option is used.

Note: The current version of dirmngr has this option disabled by default.

--allow-ocsp
This option enables OCSP support if requested by the client.

OCSP requests are rejected by default because they may violate the privacy of the user; for
example it is possible to track the time when a user is reading a mail.

--ocsp-responder url
Use url as the default OCSP Responder if the certificate does not contain information about an
assigned responder. Note, that --ocsp-signer must also be set to a valid certificate.

--ocsp-signer fpr|file
Use the certificate with the fingerprint fpr to check the responses of the default OCSP Responder.
Alternativly a filename can be given in which case the respinse is expected to be signed by one of
the certificates described in that file. Any argument which contains a slash, dot or tilde is
considered a filename. Usual filename expansion takes place: A tilde at the start followed by a
slash is replaced by the content of ‘HOME’, no slash at start describes a relative filename which
will be searched at the home directory. To make sure that the file is searched in the home
directory, either prepend the name with "./" or use a name which contains a dot.

If a response has been signed by a certificate described by these fingerprints no further check
upon the validity of this certificate is done.

The format of the FILE is a list of SHA-1 fingerprint, one per line with optional colons between
the bytes. Empty lines and lines prefix with a hash mark are ignored.

--ocsp-max-clock-skew n
The number of seconds a skew between the OCSP responder and them local clock is accepted. Default
is 600 (20 minutes).

--ocsp-max-period n
Seconds a response is at maximum considered valid after the time given in the thisUpdate field.
Default is 7776000 (90 days).

--ocsp-current-period n
The number of seconds an OCSP response is considered valid after the time given in the NEXT_UPDATE
datum. Default is 10800 (3 hours).

--max-replies n
Do not return more that n items in one query. The default is 10.

--ignore-cert-extension oid
Add oid to the list of ignored certificate extensions. The oid is expected to be in dotted
decimal form, like 2.5.29.3. This option may be used more than once. Critical flagged
certificate extensions matching one of the OIDs in the list are treated as if they are actually
handled and thus the certificate won't be rejected due to an unknown critical extension. Use this
option with care because extensions are usually flagged as critical for a reason.

--hkp-cacert file
Use the root certificates in file for verification of the TLS certificates used with hkps
(keyserver access over TLS). If the file is in PEM format a suffix of .pem is expected for file.
This option may be given multiple times to add more root certificates. Tilde expansion is
supported.

EXAMPLES

       Here is an example on how to show dirmngr's internal table of OpenPGP keyserver addresses.  The output is
       intended for debugging purposes and not part of a defined API.

           gpg-connect-agent --dirmngr 'keyserver --hosttable' /bye

       To inhibit the use of a particular host you have noticed in one of the keyserver pools, you may use

          gpg-connect-agent --dirmngr 'keyserver --dead pgpkeys.bnd.de' /bye

       The description of the keyserver command can be printed using

          gpg-connect-agent --dirmngr 'help keyserver' /bye

FILES

Dirmngr makes use of several directories when running in daemon mode:

~/.gnupg

/etc/gnupg
The first is the standard home directory for all configuration files. In the deprecated system
daemon mode the second directory is used instead.

/etc/gnupg/trusted-certs
This directory should be filled with certificates of Root CAs you are trusting in checking the
CRLs and signing OCSP Reponses.

Usually these are the same certificates you use with the applications making use of dirmngr. It
is expected that each of these certificate files contain exactly one DER encoded certificate in a
file with the suffix ‘.crt’ or ‘.der’. dirmngr reads those certificates on startup and when given
a SIGHUP. Certificates which are not readable or do not make up a proper X.509 certificate are
ignored; see the log file for details.

Applications using dirmngr (e.g. gpgsm) can request these certificates to complete a trust chain
in the same way as with the extra-certs directory (see below).

Note that for OCSP responses the certificate specified using the option --ocsp-signer is always
considered valid to sign OCSP requests.

/etc/gnupg/extra-certs
This directory may contain extra certificates which are preloaded into the interal cache on
startup. Applications using dirmngr (e.g. gpgsm) can request cached certificates to complete a
trust chain. This is convenient in cases you have a couple intermediate CA certificates or
certificates ususally used to sign OCSP reponses. These certificates are first tried before going
out to the net to look for them. These certificates must also be DER encoded and suffixed with
‘.crt’ or ‘.der’.

/var/run/gnupg2
This directory is only used in the deprecated system daemon mode. It keeps the socket file for
accessing dirmngr services. The name of the socket file will be ‘S.dirmngr’. Make sure that this
directory has the proper permissions to let dirmngr create the socket file and that eligible users
may read and write to that socket.

~/.gnupg/crls.d

/var/cache/gnupg2/crls.d
The first directory is used to store cached CRLs. The ‘crls.d’ part will be created by dirmngr if
it does not exists but you need to make sure that the upper directory exists. The second
directory is used instead in the deprecated systems daemon mode.

SIGNALS

       A  running  dirmngr  may  be  controlled  by signals, i.e. using the kill command to send a signal to the
       process.

       Here is a list of supported signals:

       SIGHUP This signals flushes all internally cached CRLs as well as  any  cached  certificates.   Then  the
              certificate  cache  is  reinitialized  as  on startup.  Options are re-read from the configuration
              file.  Instead of sending this signal it is better to use
         gpgconf --reload dirmngr

       SIGTERM
              Shuts down the process but waits until all current requests are fulfilled.   If  the  process  has
              received  3  of  these signals and requests are still pending, a shutdown is forced.  You may also
              use
         gpgconf --kill dirmngr
       instead of this signal

       SIGINT Shuts down the process immediately.

       SIGUSR1
              This prints some caching statistics to the log file.