path: root/doc/tools.texi

@c Copyright (C) 2004 Free Software Foundation, Inc.
@c This is part of the GnuPG manual.
@c For copying conditions, see the file GnuPG.texi.

@node Helper Tools
@chapter Helper Tools

GnuPG comes with a couple of smaller tools:

@menu
* watchgnupg::            Read logs from a socket.
* addgnupghome::          Create .gnupg home directories.
* gpgconf::               Modify .gnupg home directories.
* gpgsm-gencert.sh::      Generate an X.509 certificate request.
* gpg-preset-passphrase:: Put a passphrase into the cache.
* gpg-connect-agent::     Communicate with a running agent.
* symcryptrun::           Call a simple symmetric encryption tool.
@end menu

@c
@c  WATCHGNUPG
@c
@node watchgnupg
@section Read logs from a socket

Most of the main utilities are able to write there log files to a
Unix Domain socket if configured that way.  @command{watchgnupg} is a simple
listener for such a socket.  It ameliorates the output with a time
stamp and makes sure that long lines are not interspersed with log
output from other utilities.

@noindent
@command{watchgnupg} is commonly invoked as

@samp{watchgnupg --force ~/.gnupg/S.log}

@noindent
This starts it on the current terminal for listening on the socket
@file{~/.gnupg/S.log}.  

@noindent
@command{watchgnupg} understands these options:

@table @gnupgtabopt

@item --force 
@opindex force
Delete an already existing socket file.

@item --verbose
@opindex verbose
Enable extra informational output.

@item --version
@opindex version
print version of the program and exit

@item --help
@opindex help
Display a brief help page and exit

@end table


@c
@c    ADDGNUPGHOME
@c
@node addgnupghome
@section Create .gnupg home directories.

If GnuPG is installed on a system with existing user accounts, it is
sometimes required to populate the GnuPG home directory with existing
files.  Especially a @file{trustlist.txt} and a keybox with some
initial certificates are often desired.  This scripts help to do this
by copying all files from @file{/etc/skel/.gnupg} to the home
directories of the accounts given on the command line.  It takes care
not to overwrite existing GnuPG home directories.

@noindent
@command{addgnupghome} is invoked by root as:

@samp{addgnupghome account1 account2 ... accountn}


@c
@c   GPGCONF
@c
@node gpgconf
@section Modify .gnupg home directories.

The @command{gpgconf} is a utility to automatically and reasonable
safely query and modify configuration files in the @file{.gnupg} home
directory.  It is designed not to be invoked manually by the user, but
automatically by graphical user interfaces (GUI).@footnote{Please note
that currently no locking is done, so concurrent access should be
avoided.  There are some precautions to avoid corruption with
concurrent usage, but results may be inconsistent and some changes may
get lost.  The stateless design makes it difficult to provide more
guarantees.}

@command{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
@command{gpgconf}.  @command{gpgconf} provides a generic and abstract
method to access the most important configuration options that can
feasibly be controlled via such a mechanism.

@command{gpgconf} can be used to gather and change the options
available in each component, and can also provide their default
values.  @command{gpgconf} will give detailed type information that
can be used to restrict the user's input without making an attempt to
commit the changes.

@command{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 @command{gpgconf} again.  Such a
program that uses @command{gpgconf} in this way will be called GUI
throughout this section.

@menu
* Invoking gpgconf::      List of all commands and options.
* Format conventions::    Formatting conventions relevant for all commands.
* Listing components::    List all gpgconf components.
* Listing options::       List all options of a component.
* Changing options::      Changing options of a component.
@end menu


@node Invoking gpgconf
@subsection Invoking gpgconf

One of the following commands must be given:

@table @gnupgtabopt
@item --list-components
List all components.  This is the default command used if none is
specified.

@item --list-options @var{component}
List all options of the component @var{component}.

@item --change-options @var{component}
Change the options of the component @var{component}.
@end table

The following options may be used:

@table @gnupgtabopt
@c FIXME: Not yet supported.
@c @item -o @var{file}
@c @itemx --output @var{file}
@c Use @var{file} as output file.

@item -v
@itemx --verbose
Outputs additional information while running.  Specifically, this
extends numerical field values by human-readable descriptions.

@c FIXME: Not yet supported.
@c @item -n
@c @itemx --dry-run
@c Do not actually change anything.  Useful together with
@c @code{--change-options} for testing purposes.

@item -r
@itemx --runtime
Only used together with @code{--change-options}.  If one of the
modified options can be changed in a running daemon process, signal
the running daemon to ask it to reparse its configuration file after
changing.

This means that 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.
@end table


@node Format conventions
@subsection Format conventions

Some lines in the output of @command{gpgconf} contain a list of
colon-separated fields.  The following conventions apply:

@itemize @bullet
@item
The GUI program is required to strip off trailing newline and/or
carriage return characters from the output.

@item
@command{gpgconf} will never leave out fields.  If a certain version
provides a certain field, this field will always be present in all
@command{gpgconf} versions from that time on.

@item
Future versions of @command{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.

@item
Not all fields are defined under all conditions.  You are required to
ignore the content of undefined fields.
@end itemize

There are several standard types for the content of a field:

@table @asis
@item verbatim
Some fields contain strings that are not escaped in any way.  Such
fields are described to be used @emph{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.

@item percent-escaped
Some fields contain strings that are described to be
@emph{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 @code{%XY} by the byte
that has the hexadecimal value @code{XY}.  @code{X} and @code{Y} are
from the set @code{0-9a-f}.

@item localised
Some fields contain strings that are described to be @emph{localised}.
Such strings are translated to the active language and formatted in
the active character set.

@item @w{unsigned number}
Some fields contain an @emph{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 (if the verbose option is used).  You should ignore everything
in the field that follows the number.

@item @w{signed number}
Some fields contain a @emph{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 (if
the verbose option is used).  You should ignore everything in the
field that follows the number.

@item option
Some fields contain an @emph{option} argument.  The format of an
option argument depends on the type of the option and on some flags:

@table @asis
@item no argument
The simplest case is that the option does not take an argument at all
(@var{type} @code{0}).  Then the option argument is an unsigned number
that specifies how often the option occurs.  If the @code{list} flag
is not set, then the only valid number is @code{1}.  Options that do
not take an argument never have the @code{default} or @code{optional
arg} flag set.

@item number
If the option takes a number argument (@var{alt-type} is @code{2} or
@code{3}), and it can only occur once (@code{list} flag is not set),
then the option argument is either empty (only allowed if the argument
is optional), 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 @var{alt-type}).

@item number list
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.

@item string
If the option takes a string argument (@var{alt-type} is 1), and it
can only occur once (@code{list} flag is not set) then the option
argument is either empty (only allowed if the argument is optional),
or it starts with a double quote character (@code{"}) 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.

@item string list
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 string arguments as described above.
@end table
@end table

The active language and character set are currently determined from
the locale environment of the @command{gpgconf} program.

@c FIXME: Document the active language and active character set.  Allow
@c to change it via the command line?


@node Listing components
@subsection Listing components

The command @code{--list-components} will list all components that can
be configured with @command{gpgconf}.  Usually, one component will
correspond to one GnuPG-related program and contain the options of
that programs configuration file that can be modified using
@command{gpgconf}.  However, this is not necessarily the case.  A
component might also be a group of selected options from several
programs, or contain entirely virtual options that have a special
effect rather than changing exactly one option in one configuration
file.

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 command argument @code{--list-components} lists all available
components, one per line.  The format of each line is:

@code{@var{name}:@var{description}}

@table @var
@item name
This field contains a name tag of the component.  The name tag is used
to specify the component in all communication with @command{gpgconf}.
The name tag is to be used @emph{verbatim}.  It is thus not in any
escaped format.

@item description
The @emph{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 @emph{percent-escaped} and
@emph{localized}.
@end table

Example:
@example
$ gpgconf --list-components
gpg:GPG for OpenPGP
gpg-agent:GPG Agent
scdaemon:Smartcard Daemon
gpgsm:GPG for S/MIME
dirmngr:Directory Manager
@end example


@node Listing options
@subsection Listing options

Every component contains one or more options.  Options may be gathered
into option groups to allow the GUI to give visual hints to the user
about which options are related.

The command argument @code{@w{--list-options @var{component}}} lists
all options (and the groups they belong to) in the component
@var{component}, one per line.  @var{component} must be the string in
the field @var{name} in the output of the @code{--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.  There does not need to be any group (and in
this case the output will stop after the last non-grouped option).

The format of each line is:

@code{@var{name}:@var{flags}:@var{level}:@var{description}:@var{type}:@var{alt-type}:@var{argname}:@var{default}:@var{argdef}:@var{value}}

@table @var
@item 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
@command{gpgconf}.  The name tag is to be used @emph{verbatim}.  It is
thus not in any escaped format.

@item flags
The flags field contains an @emph{unsigned number}.  Its value is the
OR-wise combination of the following flag values:

@table @code
@item group (1)
If this flag is set, this is a line describing a group and not an
option.
@end table

The following flag values are only defined for options (that is, if
the @code{group} flag is not used).

@table @code
@item optional arg (2)
If this flag is set, the argument is optional.  This is never set for
@var{type} @code{0} (none) options.

@item list (4)
If this flag is set, the option can be given multiple times.

@item runtime (8)
If this flag is set, the option can be changed at runtime.

@item default (16)
If this flag is set, a default value is available.

@item default desc (32)
If this flag is set, a (runtime) default is available.  This and the
@code{default} flag are mutually exclusive.

@item no arg desc (64)
If this flag is set, and the @code{optional arg} flag is set, then the
option has a special meaning if no argument is given.
@end table

@item level
This field is defined for options and for groups.  It contains an
@emph{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):

@table @code
@item basic (0)
This option should always be offered to the user.

@item advanced (1)
This option may be offered to advanced users.

@item expert (2)
This option should only be offered to expert users.

@item invisible (3)
This option should normally never be displayed, not even to expert
users.

@item internal (4)
This option is for internal use only.  Ignore it.
@end table

The level of a group will always be the lowest level of all options it
contains.

@item description
This field is defined for options and groups.  The @emph{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 @emph{percent-escaped} and @emph{localized}.

@item type
This field is only defined for options.  It contains an @emph{unsigned
number} that specifies the type of the option's argument, if any.  The
following types are defined:

Basic types:

@table @code
@item none (0)
No argument allowed.

@item string (1)
An @emph{unformatted string}.

@item int32 (2)
A @emph{signed number}.

@item uint32 (3)
An @emph{unsigned number}.
@end table

Complex types:

@table @code
@item pathname (32)
A @emph{string} that describes the pathname of a file.  The file does
not necessarily need to exist.

@item ldap server (33)
A @emph{string} that describes an LDAP server in the format:

@code{@var{hostname}:@var{port}:@var{username}:@var{password}:@var{base_dn}}
@end table

More types will be added in the future.  Please see the @var{alt-type}
field for information on how to cope with unknown types.

@item alt-type
This field is identical to @var{type}, except that only the types
@code{0} to @code{31} are allowed.  The GUI is expected to present the
user the option in the format specified by @var{type}.  But if the
argument type @var{type} is not supported by the GUI, it can still
display the option in the more generic basic type @var{alt-type}.  The
GUI must support all the defined basic types to be able to display all
options.  More basic types may be added in future versions.  If the
GUI encounters a basic type it doesn't support, it should report an
error and abort the operation.

@item argname
This field is only defined for options with an argument type
@var{type} that is not @code{0}.  In this case it may contain a
@emph{percent-escaped} and @emph{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.

@item default
This field is defined only for options.  Its format is that of an
@emph{option argument} (@xref{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.

@item argdef
This field is defined only for options for which the @code{optional
arg} flag is set.  If the @code{no arg desc} flag is not set, its
format is that of an @emph{option argument} (@xref{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.  If the @code{no arg desc} flag is set, the field is
either empty or contains a description of the effect of this option if
no argument is given.  Note that this field is also meaningful if the
option itself does not take a real argument.

@item value
This field is defined only for options.  Its format is that of an
@emph{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.
@end table


@node Changing options
@subsection Changing options

The command @w{@code{--change-options @var{component}}} will attempt
to change the options of the component @var{component} to the
specified values.  @var{component} must be the string in the field
@var{name} in the output of the @code{--list-components} command.  You
have to provide the options that shall be changed in the following
format on standard input:

@code{@var{name}:@var{flags}:@var{new-value}}

@table @var
@item name
This is the name of the option to change.  @var{name} must be the
string in the field @var{name} in the output of the
@code{--list-options} command.

@item flags
The flags field contains an @emph{unsigned number}.  Its value is the
OR-wise combination of the following flag values:

@table @code
@item default (16)
If this flag is set, the option is deleted and the default value is
used instead (if applicable).
@end table

@item new-value
The new value for the option.  This field is only defined if the
@code{default} flag is not set.  The format is that of an @emph{option
argument}.  If it is empty (or the field is omitted), the default
argument is used (only allowed if the argument is optional for this
option).  Otherwise, the option will be set to the specified value.
@end table

Examples:

To set the force option, which is of basic type @code{none (0)}:

@example
$ echo 'force:0:1' | gpgconf --change-options dirmngr
@end example

To delete the force option:

@example
$ echo 'force:16:' | gpgconf --change-options dirmngr
@end example

The @code{--runtime} option can influence when the changes take
effect.

@c
@c    GPGSM-GENCERT.SH
@c
@node gpgsm-gencert.sh
@section Generate an X.509 certificate request

This is a simple tool to interactivly generate a certificate request
whicl will be printed to stdout.

@noindent
@command{gpgsm-gencert.sh} is invoked as:

@samp{gpgsm-cencert.sh}



@c
@c   GPG-PRESET-PASSPHRASE
@c
@node gpg-preset-passphrase
@section Put a passphrase into the cache.

The @command{gpg-preset-passphrase} is a utility to seed the internal
cache of a running @command{gpg-agent} with passphrases.  It is mainly
useful for unattended machines, where the usual @command{pinentry} tool
may not be used and the passphrases for the to be used keys are given at
machine startup.

Passphrases set with this utility don't expire unless the
@option{--forget} option is used to explicitly clear them from the cache
--- or @command{gpg-agent} is either restarted or reloaded (by sending a
SIGHUP to it).  It is necessary to allow this passphrase presetting by
starting @command{gpg-agent} with the
@option{--allow-preset-passphrase}.

@menu
* Invoking gpg-preset-passphrase::   List of all commands and options.
@end menu


@node Invoking gpg-preset-passphrase
@subsection List of all commands and options.

@noindent
@command{gpg-preset-passphrase} is invoked this way:

@example
gpg-preset-passphrase [options] [command] @var{keygrip}
@end example

@var{keygrip} is a 40 character string of hexadecimal characters
identifying the key for which the passphrase should be set or cleared.
This keygrip is listed along with the key when running the command:
@code{gpgsm --dump-secret-keys}. One of the following command options
must be given:

@table @gnupgtabopt
@item --preset
Preset a passphrase. This is what you usually will
use. @command{gpg-preset-passphrase} will then read the passphrase from
@code{stdin}.

@item --forget
Flush the passphrase for the given keygrip from the cache.

@end table

@noindent
The following additional options may be used:

@table @gnupgtabopt
@item -v
@itemx --verbose
@opindex verbose
Output additional information while running.  

@item -P @var{string}
@itemx --passphrase @var{string}
@opindex passphrase
Instead of reading the passphrase from @code{stdin}, use the supplied
@var{string} as passphrase.  Note that this makes the passphrase visible
for other users.
@end table





@c
@c   GPG-CONNECT-AGENT
@c
@node gpg-connect-agent
@section Communicate with a runnig agent.

The @command{gpg-connect-agent} is a utility to communicate with a
running @command{gpg-agent}.  It is useful to check out the commands
gpg-agent provides using the Assuan interface.  It might also be useful
for scripting simple applications.  Inputis expected at stdin and out
put gets printed to stdout.

It is very similar to running @command{gpg-agent} in server mode; but
here we connect to a running instance.

@menu
* Invoking gpg-connect-agent::   List of all commands and options.
@end menu


@node Invoking gpg-connect-agent
@subsection List of all commands and options.

@noindent
@command{gpg-connect-agent} is invoked this way:

@example
gpg-connect-agent [options]
@end example

@noindent
The following options may be used:

@table @gnupgtabopt
@item -v
@itemx --verbose
@opindex verbose
Output additional information while running.  

@item -q
@item --quiet
@opindex q
@opindex quiet
Try to be as quiet as possible.

@item --homedir @var{dir}
@opindex homedir
Set the name of the home directory to @var{dir}. If his option is not
used, the home directory defaults to @file{~/.gnupg}.  It is only
recognized when given on the command line.  It also overrides any home
directory stated through the environment variable @env{GNUPGHOME} or
(on W32 systems) by means on the Registry entry
@var{HKCU\Software\GNU\GnuPG:HomeDir}.


@item -S
@itemx --raw-socket @var{name}
@opindex S        
@opindex raw-socket
Connect to socket @var{name} assuming this is an Assuan style server.
Do not run any special initializations or environment checks.  This may
be used to directly connect to any Assuan style socket server.


@end table

@c
@c   SYMCRYPTRUN
@c
@node symcryptrun
@section Call a simple symmetric encryption tool.

Sometimes simple encryption tools are already in use for a long time and
there might be a desire to integrate them into the GnuPG framework.  The
protocols and encryption methods might be non-standard or not even
properly documented, so that a full-fledged encryption tool with an
interface like gpg is not doable.  @command{symcryptrun} provides a
solution: It operates by calling the external encryption/decryption
module and provides a passphrase for a key using the standard
@command{pinentry} based mechanism through @command{gpg-agent}.

Note, that @command{symcryptrun} is only available if GnuPG has been
configured with @samp{--enable-symcryptrun} at build time.

@menu
* Invoking symcryptrun::   List of all commands and options.
@end menu


@node Invoking symcryptrun
@subsection List of all commands and options.

@noindent
@command{symcryptrun} is invoked this way:

@example
symcryptrun --class CLASS --program PROGRAM --keyfile KEYFILE 
   [--decrypt | --encrypt] [inputfile]
@end example

For encryption, the plain text must be provided on STDIN or as the
argument @var{inputfile}, and the ciphertext will be output to STDOUT.
For decryption vice versa.

@var{CLASS} describes the calling conventions of the external tool.
Currently it must be given as @samp{confucius}.  @var{PROGRAM} is the
the full filename of that external tool.
 
For the class @samp{confucius} the option @option{--keyfile} is
required; @var{keyfile} is the name of a file containing the secret key,
which may be protected by a passphrase.  For detailed calling
conventions, see the source code.
 
@noindent
Note, that @command{gpg-agent} must be running before starting
@command{symcryptrun}.

@noindent
The following additional options may be used:

@table @gnupgtabopt
@item -v
@itemx --verbose
@opindex verbose
Output additional information while running.  

@item -q
@item --quiet
@opindex q
@opindex quiet
Try to be as quiet as possible.

@item --homedir @var{dir}
@opindex homedir
Set the name of the home directory to @var{dir}. If his option is not
used, the home directory defaults to @file{~/.gnupg}.  It is only
recognized when given on the command line.  It also overrides any home
directory stated through the environment variable @env{GNUPGHOME} or
(on W32 systems) by means on the Registry entry
@var{HKCU\Software\GNU\GnuPG:HomeDir}.

@item --log-file @var{file}
@opindex log-file
Append all logging output to @var{file}.  Default is to write logging
informaton to STDERR.

@end table

@noindent
The possible exit status codes of @command{symcryptrun} are:

@table @code
@item 0 
        Success.
@item 1 
        Some error occured.
@item 2 
        No valid passphrase was provided.
@item 3 
        The operation was canceled by the user.

@end table