4.3 Configuration files

There are a few configuration files to control certain aspects of gpgsm's operation. Unless noted, they are expected in the current home directory (see option –homedir).

gpgsm.conf

This is the standard configuration file read by gpgsm on startup. It may contain any valid long option; the leading two dashes may not be entered and the option may not be abbreviated. This default name may be changed on the command line (see option –options).

policies.txt

This is a list of allowed CA policies. This file should list the object identifiers of the policies line by line. Empty lines and lines starting with a hash mark are ignored. Policies missing in this file and not marked as critical in the certificate will print only a warning; certificates with policies marked as critical and not listed in this file will fail the signature verification.

For example, to allow only the policy 2.289.9.9, the file should look like this:

          # Allowed policies
          2.289.9.9

qualified.txt

This is the list of root certificates used for qualified certificates. They are defined as certificates capable of creating legally binding signatures in the same way as handwritten signatures are. Comments start with a hash mark and empty lines are ignored. Lines do have a length limit but this is not a serious limitation as the format of the entries is fixed and checked by gpgsm: A non-comment line starts with optional whitespace, followed by exactly 40 hex character, white space and a lowercased 2 letter country code. Additional data delimited with by a white space is current ignored but might late be used for other purposes.

Note that even if a certificate is listed in this file, this does not mean that the certificate is trusted; in general the certificates listed in this file need to be listed also in trustlist.txt.

This is a global file an installed in the data directory (e.g. /usr/share/gnupg/qualified.txt). GnuPG installs a suitable file with root certificates as used in Germany. As new Root-CA certificates may be issued over time, these entries may need to be updated; new distributions of this software should come with an updated list but it is still the responsibility of the Administrator to check that this list is correct.

Everytime gpgsm uses a certificate for signing or verification this file will be consulted to check whether the certificate under question has ultimately been issued by one of these CAs. If this is the case the user will be informed that the verified signature represents a legally binding (“qualified”) signature. When creating a signature using such a certificate an extra prompt will be issued to let the user confirm that such a legally binding signature shall really be created.

Because this software has not yet been approved for use with such certificates, appropriate notices will be shown to indicate this fact.

help.txt

This is plain text file with a few help entries used with pinentry as well as a large list of help items for gpg and gpgsm. The standard file has English help texts; to install localized versions use filenames like help.LL.txt with LL denoting the locale. GnuPG comes with a set of predefined help files in the data directory (e.g. /usr/share/gnupg/help.de.txt) and allows overriding of any help item by help files stored in the system configuration directory (e.g. /etc/gnupg/help.de.txt). For a reference of the help file's syntax, please see the installed help.txt file.

com-certs.pem

This file is a collection of common certificates used to populated a newly created pubring.kbx. An administrator may replace this file with a custom one. The format is a concatenation of PEM encoded X.509 certificates. This global file is installed in the data directory (e.g. /usr/share/gnupg/qualified.txt).

Note that on larger installations, it is useful to put predefined files into the directory /etc/skel/.gnupg/ so that newly created users start up with a working configuration. For existing users the a small helper script is provided to create these files (see addgnupghome).

For internal purposes gpgsm creates and maintaines a few other files; they all live in in the current home directory (see option –homedir). Only gpgsm may modify these files.

pubring.kbx

This a database file storing the certificates as well as meta information. For debugging purposes the tool kbxutil may be used to show the internal structure of this file.

random_seed

This content of this file is used to maintain the internal state of the random number generator accross invocations. The same file is used by other programs of this software too.

S.gpg-agent

If this file exists and the environment variable GPG_AGENT_INFO is not set, gpgsm will first try to connect to this socket for accessing gpg-agent before starting a new gpg-agent instance. Under Windows this socket (which in reality be a plain file describing a regular TCP litening port) is the standard way of connecting the gpg-agent.