============ GPG Conf ============ CONCEPT ======= gpgconf provides access to the configuration of one or more components of the GnuPG system. These components correspond more or less to the programs that exist in the GnuPG framework, like GnuPG, GPGSM, DirMngr, etc. But this is not a strict one-to-one relationship. Not all configuration options are available through GPGConf. GPGConf provides a generic and abstract method to access the most important configuration options that can feasibly be controlled via such a mechanism. GPGConf can be used to gather and change the options available in each component, and can also provide their default values. GPGConf will give detailed type information that can be used to restrict the user's input without making an attempt to commit the changes. GPGConf provides the backend of a configuration editor. The configuration editor would usually be a graphical user interface program, that allows to display the current options, their default values, and allows the user to make changes to the options. These changes can then be made active with GPGConf again. Such a program that uses GPGConf in this way will be called 'GUI' throughout this document. Format Conventions ================== Some lines in the output of GPGConf contain a list of colon-separated fields. The following conventions apply: The GUI program is required to strip off trailing newline and/or carriage return characters from the output. GPGConf will never leave out fields. If a certain version documents a certain field, this field will always be present in all GPGConf versions from that time on. Future versions of GPGConf might append fields to the list. New fields will always be separated from the previously last field by a colon separator. The GUI should be prepared to parse the last field it knows about up until a colon or end of line. Not all fields are defined under all conditions. You are required to ignore the content of undefined fields. Some fields contain strings that are not escaped in any way. Such fields are described to be used "verbatim". These fields will never contain a colon character (for obvious reasons). No de-escaping or other formatting is required to use the field content. This is for easy parsing of the output, when it is known that the content can never contain any special characters. Some fields contain strings that are described to be "percent-escaped". Such strings need to be de-escaped before their content can be presented to the user. A percent-escaped string is de-escaped by replacing all occurences of %XY by the byte that has the hexadecimal value XY. X and Y are from the set { '0'..'9', 'a'..'f' }. Some fields contain strings that are described to be "localised". Such strings are translated to the active language and formatted in the active character set. Some fields contain an unsigned number. This number will always fit into a 32-bit unsigned integer variable. The number may be followed by a space, followed by a human readable description of that value. You should ignore everything in the field that follows the number. Some fields contain a signed number. This number will always fit into a 32-bit signed integer variable. The number may be followed by a space, followed by a human readable description of that value. You should ignore everything in the field that follows the number. Some fields contain an option argument. The format of an option argument depends on the type of the option and on some flags: The simplest case is that the option does not take an argument at all (TYPE is 0). Then the option argument is either empty if the option is not set, or an unsigned number that specifies how often the option occurs. If the LIST flag is not set, then the only valid number is 1. If the option takes a number argument (ALT-TYPE is 2 or 3), and it can only occur once (LIST flag is not set), then the option argument is either empty if the option is not set, or it is a number. A number is a string that begins with an optional minus character, followed by one or more digits. The number must fit into an integer variable (unsigned or signed, depending on ALT-TYPE). If the option takes a number argument and it can occur more than once, then the option argument is either empty, or it is a comma-separated list of numbers as described above. If the option takes a string argument (ALT-TYPE is 1), and it can only occur once (LIST flag is not set) then the option argument is either empty if the option is not set, or it starts with a double quote character (") followed by a percent-escaped string that is the argument value. Note that there is only a leading double quote character, no trailing one. The double quote character is only needed to be able to differentiate between no value and the empty string as value. If the option takes a string argument and it can occur more than once, then the option argument is either empty or it starts with a double quote character (") followed by a comma-separated list of percent-escaped strings. Obviously any commas in the individual strings must be percent-escaped. FIXME: Document the active language and active character set. Allow to change it via the command line? Components ========== A component is a set of configuration options that semantically belong together. Furthermore, several changes to a component can be made in an atomic way with a single operation. The GUI could for example provide a menu with one entry for each component, or a window with one tabulator sheet per component. The following interface is provided to list the available components: Command --list-components ------------------------- Outputs a list of all components available, one per line. The format of each line is: NAME:DESCRIPTION NAME This field contains a name tag of the component. The name tag is used to specify the component in all communication with GPGConf. The name tag is to be used verbatim. It is not in any escaped format. DESCRIPTION The string in this field contains a human-readable description of the component. It can be displayed to the user of the GUI for informational purposes. It is percent-escaped and localized. Example: $ gpgconf --list-components gpg-agent:GPG Agent dirmngr:CRL Manager OPTIONS ======= Every component contains one or more options. Options may belong to a group. The following command lists all options and the groups they belong to: Command --list-options COMPONENT -------------------------------- Lists all options (and the groups they belong to) in the component COMPONENT. COMPONENT is the string in the field NAME in the output of the --list-components command. There is one line for each option and each group. First come all options that are not in any group. Then comes a line describing a group. Then come all options that belong into each group. Then comes the next group and so on. The format of each line is: NAME:FLAGS:LEVEL:DESCRIPTION:TYPE:ALT-TYPE:ARGNAME:DEFAULT:VALUE NAME This field contains a name tag for the group or option. The name tag is used to specify the group or option in all communication with GPGConf. The name tag is to be used verbatim. It is not in any escaped format. FLAGS The flags field contains an unsigned number. Its value is the OR-wise combination of the following flag values: 1 group If this flag is set, this is a line describing a group and not an option. O 2 optional arg If this flag is set, the argument is optional. O 4 list If this flag is set, the option can be given multiple times. O 8 runtime If this flag is set, the option can be changed at runtime. Flags marked with a 'O' are only defined for options (ie, if the GROUP flag is not set). LEVEL This field is defined for options and for groups. It contains an unsigned number that specifies the expert level under which this group or option should be displayed. The following expert levels are defined for options (they have analogous meaning for groups): 0 basic This option should always be offered to the user. 1 advanced This option may be offered to advanced users. 2 expert This option should only be offered to expert users. 3 invisible This option should normally never be displayed, not even to expert users. 4 internal This option is for internal use only. Ignore it. The level of a group will always be the lowest level of all options it contains. DESCRIPTION This field is defined for options and groups. The string in this field contains a human-readable description of the option or group. It can be displayed to the user of the GUI for informational purposes. It is percent-escaped and localized. TYPE This field is only defined for options. It contains an unsigned number that specifies the type of the option's argument, if any. The following types are defined: 0 none No argument allowed. 1 string An unformatted string. 2 int32 A signed integer number. 3 uint32 An unsigned integer number. 4 pathname A string that describes the pathname of a file. The file does not necessarily need to exist. 5 ldap server A string that describes an LDAP server in the format HOSTNAME:PORT:USERNAME:PASSWORD:BASE_DN. More types will be added in the future. Please see the ALT-TYPE field for information on how to cope with unknown types. ALT-TYPE This field is identical to TYPE, except that only the types 0 to 3 are allowed. The GUI is expected to present the user the option in the format specified by TYPE. But if the argument type TYPE is not supported by the GUI, it can still display the option in the more generic basic type ALT-TYPE. The GUI must support the basic types 0 to 3 to be able to display all options. ARGNAME This field is only defined for options with an argument type TYPE that is not 0. In this case it may contain a percent-escaped and localised string that gives a short name for the argument. The field may also be empty, though, in which case a short name is not known. DEFAULT This field is defined only for options. Its format is that of an option argument (see section Format Conventions for details). If the default value is empty, then no default is known. Otherwise, the value specifies the default value for this option. Note that this field is also meaningful if the option itself does not take a real argument. VALUE This field is defined only for options. Its format is that of an option argument. If it is empty, then the option is not explicitely set in the current configuration, and the default applies (if any). Otherwise, it contains the current value of the option. Note that this field is also meaningful if the option itself does not take a real argument. CHANGING OPTIONS ================ To change the options for a component, you must provide them in the following format: NAME:NEW-VALUE NAME This is the name of the option to change. NEW-VALUE The new value for the option. The format is that of an option argument. If it is empty (or the field is omitted), the option will be deleted, so that the default value is used. Otherwise, the option will be set to the specified value. Option --runtime ---------------- If this option is set, the changes will take effect at run-time, as far as this is possible. Otherwise, they will take effect at the next start of the respective backend programs. BACKENDS ======== Backends should support the following commands: Command --gpgconf-list ---------------------- List the location of the configuration file, and all default values of all options. The location of the configuration file must be an absolute pathname. Example: $ dirmngr --gpgconf-list gpgconf-config-file:/mnt/marcus/.gnupg/dirmngr.conf ldapservers-file:/mnt/marcus/.gnupg/dirmngr_ldapservers.conf add-servers: max-replies:10