dirmngr Man page

DIRMNGR(8) GNU Privacy Guard 2.1 DIRMNGR(8)

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 dirm‐
ngr.

–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 configura‐
tion 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 see‐
ing 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). WARN‐
ING: As of now this still leaks the DNS queries; e.g. to lookup
the hosts in a keyserver pool. Certain other features are dis‐
abled if this mode is active.

–keyserver name
Use name as your keyserver. This is the server that gpg commu‐
nicates with to receive keys, send keys, and search for keys.
The format of the name is a URI: `scheme:[//]keyserver‐
name[: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 par‐
ticular 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 gener‐
ally 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 cer‐
tificate 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’ regard‐
less whether –honor-http-proxy has been set.

–ldap-proxy host[:port] Use host and port to connect to LDAP servers. If port is ommit‐
ted, 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 certifi‐
cates 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 solu‐
tion here than to put such a password in the binary encoding
into the file (i.e. non-ascii characters won’t show up read‐
able). ([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 file‐
name 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 cer‐
tificates. 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 direc‐
tory 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 appli‐
cations making use of dirmngr. It is expected that each of
these certificate files contain exactly one DER encoded certifi‐
cate in a file with the suffix ‘.crt’ or ‘.der’. dirmngr reads
those certificates on startup and when given a SIGHUP. Certifi‐
cates 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 cer‐
tificates 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 pre‐
loaded 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 reinitial‐
ized 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.

SEE ALSO

gpgsm(1), dirmngr-client

The full documentation for this tool is maintained as a Texinfo manual.
If GnuPG and the info program are properly installed at your site, the
command

info gnupg

should give you access to the complete manual including a menu struc‐
ture and an index.

GnuPG 2.1.11 2016-01-21 DIRMNGR(8)