1 @c Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
2 @c 2008, 2009, 2010 Free Software Foundation, Inc.
3 @c This is part of the GnuPG manual.
4 @c For copying conditions, see the file gnupg.texi.
10 @cindex GPG command options
11 @cindex command options
12 @cindex options, GPG command
15 @c Begin standard stuff
20 \- OpenPGP encryption and signing tool
37 @c Begin gpg2 hack stuff
42 \- OpenPGP encryption and signing tool
57 @c End gpg2 hack stuff
61 @command{@gpgname} is the OpenPGP part of the GNU Privacy Guard (GnuPG). It
62 is a tool to provide digital encryption and signing services using the
63 OpenPGP standard. @command{@gpgname} features complete key management and
64 all bells and whistles you can expect from a decent OpenPGP
68 Note that this version of GnuPG features all modern algorithms and
69 should thus be preferred over older GnuPG versions. If you are
70 looking for version 1 of GnuPG, you may find that version installed
71 under the name @command{gpg1}.
74 In contrast to the standalone command gpg from GnuPG 1.x, which
75 might be better suited for server and embedded platforms, the 2.x
76 version is commonly installed under the name @command{@gpgname} and
77 targeted to the desktop as it requires several other modules to be
83 @xref{Option Index}, for an index to @command{@gpgname}'s commands and options.
87 * GPG Commands:: List of all commands.
88 * GPG Options:: List of all options.
89 * GPG Configuration:: Configuration files.
90 * GPG Examples:: Some usage examples.
92 Developer information:
93 * Unattended Usage of GPG:: Using @command{gpg} from other programs.
96 @c * GPG Protocol:: The protocol the server mode uses.
99 @c *******************************************
100 @c *************** ****************
101 @c *************** COMMANDS ****************
102 @c *************** ****************
103 @c *******************************************
108 Commands are not distinguished from options except for the fact that
109 only one command is allowed.
111 @command{@gpgname} may be run with no commands, in which case it will
112 perform a reasonable action depending on the type of file it is given
113 as input (an encrypted message is decrypted, a signature is verified,
114 a file containing keys is listed).
116 Please remember that option as well as command parsing stops as soon as
117 a non-option is encountered, you can explicitly stop parsing by
118 using the special option @option{--}.
122 * General GPG Commands:: Commands not specific to the functionality.
123 * Operational GPG Commands:: Commands to select the type of operation.
124 * OpenPGP Key Management:: How to manage your keys.
128 @c *******************************************
129 @c ********** GENERAL COMMANDS *************
130 @c *******************************************
131 @node General GPG Commands
132 @subsection Commands not specific to the function
137 Print the program version and licensing information. Note that you
138 cannot abbreviate this command.
143 Print a usage message summarizing the most useful command line options.
144 Note that you cannot abbreviate this command.
148 Print warranty information.
151 @opindex dump-options
152 Print a list of all available options and commands. Note that you cannot
153 abbreviate this command.
157 @c *******************************************
158 @c ******** OPERATIONAL COMMANDS ***********
159 @c *******************************************
160 @node Operational GPG Commands
161 @subsection Commands to select the type of operation
169 Make a signature. This command may be combined with @option{--encrypt}
170 (for a signed and encrypted message), @option{--symmetric} (for a
171 signed and symmetrically encrypted message), or @option{--encrypt} and
172 @option{--symmetric} together (for a signed message that may be
173 decrypted via a secret key or a passphrase). The key to be used for
174 signing is chosen by default or can be set with the
175 @option{--local-user} and @option{--default-key} options.
179 Make a clear text signature. The content in a clear text signature is
180 readable without any special software. OpenPGP software is only needed
181 to verify the signature. Clear text signatures may modify end-of-line
182 whitespace for platform independence and are not intended to be
183 reversible. The key to be used for signing is chosen by default or
184 can be set with the @option{--local-user} and @option{--default-key}
191 Make a detached signature.
196 Encrypt data. This command may be combined with @option{--sign} (for a
197 signed and encrypted message), @option{--symmetric} (for a message that
198 may be decrypted via a secret key or a passphrase), or @option{--sign}
199 and @option{--symmetric} together (for a signed message that may be
200 decrypted via a secret key or a passphrase).
205 Encrypt with a symmetric cipher using a passphrase. The default
206 symmetric cipher used is @value{GPGSYMENCALGO}, but may be chosen with the
207 @option{--cipher-algo} option. This command may be combined with
208 @option{--sign} (for a signed and symmetrically encrypted message),
209 @option{--encrypt} (for a message that may be decrypted via a secret key
210 or a passphrase), or @option{--sign} and @option{--encrypt} together
211 (for a signed message that may be decrypted via a secret key or a
216 Store only (make a simple literal data packet).
221 Decrypt the file given on the command line (or STDIN if no file
222 is specified) and write it to STDOUT (or the file specified with
223 @option{--output}). If the decrypted file is signed, the signature is also
224 verified. This command differs from the default operation, as it never
225 writes to the filename which is included in the file and it rejects
226 files which don't begin with an encrypted message.
230 Assume that the first argument is a signed file and verify it without
231 generating any output. With no arguments, the signature packet is
232 read from STDIN. If only a one argument is given, it is expected to
233 be a complete signature.
235 With more than 1 argument, the first should be a detached signature
236 and the remaining files make up the the signed data. To read the signed
237 data from STDIN, use @samp{-} as the second filename. For security
238 reasons a detached signature cannot read the signed material from
239 STDIN without denoting it in the above way.
241 Note: If the option @option{--batch} is not used, @command{@gpgname}
242 may assume that a single argument is a file with a detached signature
243 and it will try to find a matching data file by stripping certain
244 suffixes. Using this historical feature to verify a detached
245 signature is strongly discouraged; always specify the data file too.
247 Note: When verifying a cleartext signature, @command{gpg} verifies
248 only what makes up the cleartext signed data and not any extra data
249 outside of the cleartext signature or header lines following directly
250 the dash marker line. The option @code{--output} may be used to write
251 out the actual signed data; but there are other pitfalls with this
252 format as well. It is suggested to avoid cleartext signatures in
253 favor of detached signatures.
257 This modifies certain other commands to accept multiple files for
258 processing on the command line or read from STDIN with each filename on
259 a separate line. This allows for many files to be processed at
260 once. @option{--multifile} may currently be used along with
261 @option{--verify}, @option{--encrypt}, and @option{--decrypt}. Note that
262 @option{--multifile --verify} may not be used with detached signatures.
265 @opindex verify-files
266 Identical to @option{--multifile --verify}.
268 @item --encrypt-files
269 @opindex encrypt-files
270 Identical to @option{--multifile --encrypt}.
272 @item --decrypt-files
273 @opindex decrypt-files
274 Identical to @option{--multifile --decrypt}.
278 @itemx --list-public-keys
280 List all keys from the public keyrings, or just the keys given on the
283 Avoid using the output of this command in scripts or other programs as
284 it is likely to change as GnuPG changes. See @option{--with-colons}
285 for a machine-parseable key listing command that is appropriate for
286 use in scripts and other programs. Never use the regular output for
287 scripts --- it is only for human consumption.
289 @item --list-secret-keys
291 @opindex list-secret-keys
292 List all keys from the secret keyrings, or just the ones given on the
293 command line. A @code{#} after the letters @code{sec} means that the
294 secret key is not usable (for example, if it was created via
295 @option{--export-secret-subkeys}). See also @option{--list-keys}.
299 Same as @option{--list-keys}, but the signatures are listed too.
300 This command has the same effect as
301 using @option{--list-keys} with @option{--with-sig-list}.
303 For each signature listed, there are several flags in between the "sig"
304 tag and keyid. These flags give additional information about each
305 signature. From left to right, they are the numbers 1-3 for certificate
306 check level (see @option{--ask-cert-level}), "L" for a local or
307 non-exportable signature (see @option{--lsign-key}), "R" for a
308 nonRevocable signature (see the @option{--edit-key} command "nrsign"),
309 "P" for a signature that contains a policy URL (see
310 @option{--cert-policy-url}), "N" for a signature that contains a
311 notation (see @option{--cert-notation}), "X" for an eXpired signature
312 (see @option{--ask-cert-expire}), and the numbers 1-9 or "T" for 10 and
313 above to indicate trust signature levels (see the @option{--edit-key}
318 Same as @option{--list-sigs}, but the signatures are verified. Note
319 that for performance reasons the revocation status of a signing key is
321 This command has the same effect as
322 using @option{--list-keys} with @option{--with-sig-check}.
324 The status of the verification is indicated by a flag directly following
325 the "sig" tag (and thus before the flags described above for
326 @option{--list-sigs}). A "!" indicates that the signature has been
327 successfully verified, a "-" denotes a bad signature and a "%" is used
328 if an error occurred while checking the signature (e.g. a non supported
333 Locate the keys given as arguments. This command basically uses the
334 same algorithm as used when locating keys for encryption or signing and
335 may thus be used to see what keys @command{@gpgname} might use. In
336 particular external methods as defined by @option{--auto-key-locate} may
337 be used to locate a key. Only public keys are listed.
341 List all keys (or the specified ones) along with their
342 fingerprints. This is the same output as @option{--list-keys} but with
343 the additional output of a line with the fingerprint. May also be
344 combined with @option{--list-sigs} or @option{--check-sigs}. If this
345 command is given twice, the fingerprints of all secondary keys are
346 listed too. This command also forces pretty printing of fingerprints
347 if the keyid format has been set to "none".
350 @opindex list-packets
351 List only the sequence of packets. This command is only useful for
352 debugging. When used with option @option{--verbose} the actual MPI
353 values are dumped and not only their lengths. Note that the output of
354 this command may change with new releases.
359 Present a menu to work with a smartcard. The subcommand "help" provides
360 an overview on available commands. For a detailed description, please
361 see the Card HOWTO at
362 https://gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .
366 Show the content of the smart card.
370 Present a menu to allow changing the PIN of a smartcard. This
371 functionality is also available as the subcommand "passwd" with the
372 @option{--card-edit} command.
374 @item --delete-keys @code{name}
375 @itemx --delete-keys @code{name}
376 Remove key from the public keyring. In batch mode either @option{--yes} is
377 required or the key must be specified by fingerprint. This is a
378 safeguard against accidental deletion of multiple keys.
380 @item --delete-secret-keys @code{name}
381 @opindex delete-secret-keys
382 Remove key from the secret keyring. In batch mode the key must be
383 specified by fingerprint. The option @option{--yes} can be used to
384 advice gpg-agent not to request a confirmation. This extra
385 pre-caution is done because @command{gpg} can't be sure that the
386 secret key (as controlled by gpg-agent) is only used for the given
390 @item --delete-secret-and-public-key @code{name}
391 @opindex delete-secret-and-public-key
392 Same as @option{--delete-key}, but if a secret key exists, it will be
393 removed first. In batch mode the key must be specified by fingerprint.
394 The option @option{--yes} can be used to advice gpg-agent not to
395 request a confirmation.
399 Either export all keys from all keyrings (default keyrings and those
400 registered via option @option{--keyring}), or if at least one name is given,
401 those of the given name. The exported keys are written to STDOUT or to the
402 file given with option @option{--output}. Use together with
403 @option{--armor} to mail those keys.
405 @item --send-keys @code{key IDs}
407 Similar to @option{--export} but sends the keys to a keyserver.
408 Fingerprints may be used instead of key IDs. Option @option{--keyserver}
409 must be used to give the name of this keyserver. Don't send your
410 complete keyring to a keyserver --- select only those keys which are new
411 or changed by you. If no key IDs are given, @command{gpg} does nothing.
413 @item --export-secret-keys
414 @itemx --export-secret-subkeys
415 @opindex export-secret-keys
416 @opindex export-secret-subkeys
417 Same as @option{--export}, but exports the secret keys instead. The
418 exported keys are written to STDOUT or to the file given with option
419 @option{--output}. This command is often used along with the option
420 @option{--armor} to allow easy printing of the key for paper backup;
421 however the external tool @command{paperkey} does a better job for
422 creating backups on paper. Note that exporting a secret key can be a
423 security risk if the exported keys are sent over an insecure channel.
425 The second form of the command has the special property to render the
426 secret part of the primary key useless; this is a GNU extension to
427 OpenPGP and other implementations can not be expected to successfully
428 import such a key. Its intended use is to generated a full key with
429 an additional signing subkey on a dedicated machine and then using
430 this command to export the key without the primary key to the main
433 GnuPG may ask you to enter the passphrase for the key. This is
434 required because the internal protection method of the secret key is
435 different from the one specified by the OpenPGP protocol.
437 @item --export-ssh-key
438 @opindex export-ssh-key
439 This command is used to export a key in the OpenSSH public key format.
440 It requires the specification of one key by the usual means and
441 exports the latest valid subkey which has an authentication capability
442 to STDOUT or to the file given with option @option{--output}. That
443 output can directly be added to ssh's @file{authorized_key} file.
445 By specifying the key to export using a key ID or a fingerprint
446 suffixed with an exclamation mark (!), a specific subkey or the
447 primary key can be exported. This does not even require that the key
448 has the authentication capability flag set.
453 Import/merge keys. This adds the given keys to the
454 keyring. The fast version is currently just a synonym.
456 There are a few other options which control how this command works.
457 Most notable here is the @option{--import-options merge-only} option
458 which does not insert new keys but does only the merging of new
459 signatures, user-IDs and subkeys.
461 @item --recv-keys @code{key IDs}
463 Import the keys with the given key IDs from a keyserver. Option
464 @option{--keyserver} must be used to give the name of this keyserver.
467 @opindex refresh-keys
468 Request updates from a keyserver for keys that already exist on the
469 local keyring. This is useful for updating a key with the latest
470 signatures, user IDs, etc. Calling this with no arguments will refresh
471 the entire keyring. Option @option{--keyserver} must be used to give the
472 name of the keyserver for all keys that do not have preferred keyservers
473 set (see @option{--keyserver-options honor-keyserver-url}).
475 @item --search-keys @code{names}
477 Search the keyserver for the given names. Multiple names given here will
478 be joined together to create the search string for the keyserver.
479 Option @option{--keyserver} must be used to give the name of this
480 keyserver. Keyservers that support different search methods allow using
481 the syntax specified in "How to specify a user ID" below. Note that
482 different keyserver types support different search methods. Currently
483 only LDAP supports them all.
485 @item --fetch-keys @code{URIs}
487 Retrieve keys located at the specified URIs. Note that different
488 installations of GnuPG may support different protocols (HTTP, FTP,
489 LDAP, etc.). When using HTTPS the system provided root certificates
490 are used by this command.
492 @item --update-trustdb
493 @opindex update-trustdb
494 Do trust database maintenance. This command iterates over all keys and
495 builds the Web of Trust. This is an interactive command because it may
496 have to ask for the "ownertrust" values for keys. The user has to give
497 an estimation of how far she trusts the owner of the displayed key to
498 correctly certify (sign) other keys. GnuPG only asks for the ownertrust
499 value if it has not yet been assigned to a key. Using the
500 @option{--edit-key} menu, the assigned value can be changed at any time.
502 @item --check-trustdb
503 @opindex check-trustdb
504 Do trust database maintenance without user interaction. From time to
505 time the trust database must be updated so that expired keys or
506 signatures and the resulting changes in the Web of Trust can be
507 tracked. Normally, GnuPG will calculate when this is required and do it
508 automatically unless @option{--no-auto-check-trustdb} is set. This
509 command can be used to force a trust database check at any time. The
510 processing is identical to that of @option{--update-trustdb} but it
511 skips keys with a not yet defined "ownertrust".
513 For use with cron jobs, this command can be used together with
514 @option{--batch} in which case the trust database check is done only if
515 a check is needed. To force a run even in batch mode add the option
518 @anchor{option --export-ownertrust}
519 @item --export-ownertrust
520 @opindex export-ownertrust
521 Send the ownertrust values to STDOUT. This is useful for backup purposes
522 as these values are the only ones which can't be re-created from a
523 corrupted trustdb. Example:
526 @gpgname{} --export-ownertrust > otrust.txt
531 @item --import-ownertrust
532 @opindex import-ownertrust
533 Update the trustdb with the ownertrust values stored in @code{files} (or
534 STDIN if not given); existing values will be overwritten. In case of a
535 severely damaged trustdb and if you have a recent backup of the
536 ownertrust values (e.g. in the file @file{otrust.txt}), you may re-create
537 the trustdb using these commands:
542 @gpgname{} --import-ownertrust < otrust.txt
547 @item --rebuild-keydb-caches
548 @opindex rebuild-keydb-caches
549 When updating from version 1.0.6 to 1.0.7 this command should be used
550 to create signature caches in the keyring. It might be handy in other
553 @item --print-md @code{algo}
556 Print message digest of algorithm ALGO for all given files or STDIN.
557 With the second form (or a deprecated "*" as algo) digests for all
558 available algorithms are printed.
560 @item --gen-random @code{0|1|2} @code{count}
562 Emit @var{count} random bytes of the given quality level 0, 1 or 2. If
563 @var{count} is not given or zero, an endless sequence of random bytes
564 will be emitted. If used with @option{--armor} the output will be
565 base64 encoded. PLEASE, don't use this command unless you know what
566 you are doing; it may remove precious entropy from the system!
568 @item --gen-prime @code{mode} @code{bits}
570 Use the source, Luke :-). The output format is still subject to change.
577 Pack or unpack an arbitrary input into/from an OpenPGP ASCII armor.
578 This is a GnuPG extension to OpenPGP and in general not very useful.
580 @item --tofu-policy @code{auto|good|unknown|bad|ask} @code{key...}
582 Set the TOFU policy for all the bindings associated with the specified
583 keys. For more information about the meaning of the policies,
584 @pxref{trust-model-tofu}. The keys may be specified either by their
585 fingerprint (preferred) or their keyid.
589 @c Run gpg in server mode. This feature is not yet ready for use and
590 @c thus not documented.
595 @c *******************************************
596 @c ******* KEY MANGEMENT COMMANDS **********
597 @c *******************************************
598 @node OpenPGP Key Management
599 @subsection How to manage your keys
601 This section explains the main commands for key management.
605 @item --quick-gen-key @code{user-id} [@code{algo} [@code{usage} [@code{expire}]]]
606 @opindex quick-gen-key
607 This is a simple command to generate a standard key with one user id.
608 In contrast to @option{--gen-key} the key is generated directly
609 without the need to answer a bunch of prompts. Unless the option
610 @option{--yes} is given, the key creation will be canceled if the
611 given user id already exists in the keyring.
613 If invoked directly on the console without any special options an
614 answer to a ``Continue?'' style confirmation prompt is required. In
615 case the user id already exists in the keyring a second prompt to
616 force the creation of the key will show up.
618 If @code{algo} or @code{usage} are given, only the primary key is
619 created and no prompts are shown. To specify an expiration date but
620 still create a primary and subkey use ``default'' or
621 ``future-default'' for @code{algo} and ``default'' for @code{usage}.
622 For a description of these optional arguments see the command
623 @code{--quick-addkey}. The @code{usage} accepts also the value
624 ``cert'' which can be used to create a certification only primary key;
625 the default is to a create certification and signing key.
627 If this command is used with @option{--batch},
628 @option{--pinentry-mode} has been set to @code{loopback}, and one of
629 the passphrase options (@option{--passphrase},
630 @option{--passphrase-fd}, or @option{passphrase-file}) is used, the
631 supplied passphrase is used for the new key and the agent does not ask
632 for it. To create a key without any protection @code{--passphrase ''}
635 @item --quick-addkey @code{fpr} [@code{algo} [@code{usage} [@code{expire}]]]
636 @opindex quick-addkey
637 Directly add a subkey to the key identified by the fingerprint
638 @code{fpr}. Without the optional arguments an encryption subkey is
639 added. If any of the arguments are given a more specific subkey is
642 @code{algo} may be any of the supported algorithms or curve names
643 given in the format as used by key listings. To use the default
644 algorithm the string ``default'' or ``-'' can be used. Supported
645 algorithms are ``rsa'', ``dsa'', ``elg'', ``ed25519'', ``cv25519'',
646 and other ECC curves. For example the string ``rsa'' adds an RSA key
647 with the default key length; a string ``rsa4096'' requests that the
648 key length is 4096 bits. The string ``future-default'' is an alias
649 for the algorithm which will likely be used as default algorithm in
650 future versions of gpg.
652 Depending on the given @code{algo} the subkey may either be an
653 encryption subkey or a signing subkey. If an algorithm is capable of
654 signing and encryption and such a subkey is desired, a @code{usage}
655 string must be given. This string is either ``default'' or ``-'' to
656 keep the default or a comma delimited list of keywords: ``sign'' for a
657 signing subkey, ``auth'' for an authentication subkey, and ``encr''
658 for an encryption subkey (``encrypt'' can be used as alias for
659 ``encr''). The valid combinations depend on the algorithm.
661 The @code{expire} argument can be used to specify an expiration date
662 for the subkey. Several formats are supported; commonly the ISO
663 YYYY-MM-DD format is used. The values ``never'', ``none'', or ``-''
664 can be used for no expiration date.
668 Generate a new key pair using the current default parameters. This is
669 the standard command to create a new key. In addition to the key a
670 revocation certificate is created and stored in the
671 @file{openpgp-revocs.d} directory below the GnuPG home directory.
675 Generate a new key pair with dialogs for all options. This is an
676 extended version of @option{--gen-key}.
678 There is also a feature which allows you to create keys in batch
679 mode. See the manual section ``Unattended key generation'' on how
683 @item --gen-revoke @code{name}
685 Generate a revocation certificate for the complete key. To only revoke
686 a subkey or a key signature, use the @option{--edit} command.
688 This command merely creates the revocation certificate so that it can
689 be used to revoke the key if that is ever needed. To actually revoke
690 a key the created revocation certificate needs to be merged with the
691 key to revoke. This is done by importing the revocation certificate
692 using the @option{--import} command. Then the revoked key needs to be
693 published, which is best done by sending the key to a keyserver
694 (command @option{--send-key}) and by exporting (@option{--export}) it
695 to a file which is then send to frequent communication partners.
698 @item --desig-revoke @code{name}
699 @opindex desig-revoke
700 Generate a designated revocation certificate for a key. This allows a
701 user (with the permission of the keyholder) to revoke someone else's
707 Present a menu which enables you to do most of the key management
708 related tasks. It expects the specification of a key on the command
711 @c ******** Begin Edit-key Options **********
716 Toggle selection of user ID or photographic user ID with index @code{n}.
717 Use @code{*} to select all and @code{0} to deselect all.
721 Toggle selection of subkey with index @code{n} or key ID @code{n}.
722 Use @code{*} to select all and @code{0} to deselect all.
725 @opindex keyedit:sign
726 Make a signature on key of user @code{name}. If the key is not yet
727 signed by the default user (or the users given with @option{-u}), the program
728 displays the information of the key again, together with its
729 fingerprint and asks whether it should be signed. This question is
730 repeated for all users specified with
734 @opindex keyedit:lsign
735 Same as "sign" but the signature is marked as non-exportable and will
736 therefore never be used by others. This may be used to make keys
737 valid only in the local environment.
740 @opindex keyedit:nrsign
741 Same as "sign" but the signature is marked as non-revocable and can
742 therefore never be revoked.
745 @opindex keyedit:tsign
746 Make a trust signature. This is a signature that combines the notions
747 of certification (like a regular signature), and trust (like the
748 "trust" command). It is generally only useful in distinct communities
749 or groups. For more information please read the sections
750 ``Trust Signature'' and ``Regular Expression'' in RFC-4880.
754 Note that "l" (for local / non-exportable), "nr" (for non-revocable,
755 and "t" (for trust) may be freely mixed and prefixed to "sign" to
756 create a signature of any type desired.
759 If the option @option{--only-sign-text-ids} is specified, then any
760 non-text based user ids (e.g., photo IDs) will not be selected for
766 @opindex keyedit:delsig
767 Delete a signature. Note that it is not possible to retract a signature,
768 once it has been send to the public (i.e. to a keyserver). In that case
769 you better use @code{revsig}.
772 @opindex keyedit:revsig
773 Revoke a signature. For every signature which has been generated by
774 one of the secret keys, GnuPG asks whether a revocation certificate
778 @opindex keyedit:check
779 Check the signatures on all selected user IDs. With the extra
780 option @code{selfsig} only self-signatures are shown.
783 @opindex keyedit:adduid
784 Create an additional user ID.
787 @opindex keyedit:addphoto
788 Create a photographic user ID. This will prompt for a JPEG file that
789 will be embedded into the user ID. Note that a very large JPEG will make
790 for a very large key. Also note that some programs will display your
791 JPEG unchanged (GnuPG), and some programs will scale it to fit in a
795 @opindex keyedit:showphoto
796 Display the selected photographic user ID.
799 @opindex keyedit:deluid
800 Delete a user ID or photographic user ID. Note that it is not
801 possible to retract a user id, once it has been send to the public
802 (i.e. to a keyserver). In that case you better use @code{revuid}.
805 @opindex keyedit:revuid
806 Revoke a user ID or photographic user ID.
809 @opindex keyedit:primary
810 Flag the current user id as the primary one, removes the primary user
811 id flag from all other user ids and sets the timestamp of all affected
812 self-signatures one second ahead. Note that setting a photo user ID
813 as primary makes it primary over other photo user IDs, and setting a
814 regular user ID as primary makes it primary over other regular user
818 @opindex keyedit:keyserver
819 Set a preferred keyserver for the specified user ID(s). This allows
820 other users to know where you prefer they get your key from. See
821 @option{--keyserver-options honor-keyserver-url} for more on how this
822 works. Setting a value of "none" removes an existing preferred
826 @opindex keyedit:notation
827 Set a name=value notation for the specified user ID(s). See
828 @option{--cert-notation} for more on how this works. Setting a value of
829 "none" removes all notations, setting a notation prefixed with a minus
830 sign (-) removes that notation, and setting a notation name (without the
831 =value) prefixed with a minus sign removes all notations with that name.
834 @opindex keyedit:pref
835 List preferences from the selected user ID. This shows the actual
836 preferences, without including any implied preferences.
839 @opindex keyedit:showpref
840 More verbose preferences listing for the selected user ID. This shows
841 the preferences in effect by including the implied preferences of 3DES
842 (cipher), SHA-1 (digest), and Uncompressed (compression) if they are
843 not already included in the preference list. In addition, the
844 preferred keyserver and signature notations (if any) are shown.
846 @item setpref @code{string}
847 @opindex keyedit:setpref
848 Set the list of user ID preferences to @code{string} for all (or just
849 the selected) user IDs. Calling setpref with no arguments sets the
850 preference list to the default (either built-in or set via
851 @option{--default-preference-list}), and calling setpref with "none"
852 as the argument sets an empty preference list. Use @command{@gpgname
853 --version} to get a list of available algorithms. Note that while you
854 can change the preferences on an attribute user ID (aka "photo ID"),
855 GnuPG does not select keys via attribute user IDs so these preferences
856 will not be used by GnuPG.
858 When setting preferences, you should list the algorithms in the order
859 which you'd like to see them used by someone else when encrypting a
860 message to your key. If you don't include 3DES, it will be
861 automatically added at the end. Note that there are many factors that
862 go into choosing an algorithm (for example, your key may not be the
863 only recipient), and so the remote OpenPGP application being used to
864 send to you may or may not follow your exact chosen order for a given
865 message. It will, however, only choose an algorithm that is present
866 on the preference list of every recipient key. See also the
867 INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below.
870 @opindex keyedit:addkey
871 Add a subkey to this key.
874 @opindex keyedit:addcardkey
875 Generate a subkey on a card and add it to this key.
878 @opindex keyedit:keytocard
879 Transfer the selected secret subkey (or the primary key if no subkey
880 has been selected) to a smartcard. The secret key in the keyring will
881 be replaced by a stub if the key could be stored successfully on the
882 card and you use the save command later. Only certain key types may be
883 transferred to the card. A sub menu allows you to select on what card
884 to store the key. Note that it is not possible to get that key back
885 from the card - if the card gets broken your secret key will be lost
886 unless you have a backup somewhere.
888 @item bkuptocard @code{file}
889 @opindex keyedit:bkuptocard
890 Restore the given file to a card. This command may be used to restore a
891 backup key (as generated during card initialization) to a new card. In
892 almost all cases this will be the encryption key. You should use this
893 command only with the corresponding public key and make sure that the
894 file given as argument is indeed the backup to restore. You should then
895 select 2 to restore as encryption key. You will first be asked to enter
896 the passphrase of the backup key and then for the Admin PIN of the card.
899 @opindex keyedit:delkey
900 Remove a subkey (secondary key). Note that it is not possible to retract
901 a subkey, once it has been send to the public (i.e. to a keyserver). In
902 that case you better use @code{revkey}.
905 @opindex keyedit:revkey
909 @opindex keyedit:expire
910 Change the key or subkey expiration time. If a subkey is selected, the
911 expiration time of this subkey will be changed. With no selection, the
912 key expiration of the primary key is changed.
915 @opindex keyedit:trust
916 Change the owner trust value for the key. This updates the trust-db
917 immediately and no save is required.
921 @opindex keyedit:disable
922 @opindex keyedit:enable
923 Disable or enable an entire key. A disabled key can not normally be
927 @opindex keyedit:addrevoker
928 Add a designated revoker to the key. This takes one optional argument:
929 "sensitive". If a designated revoker is marked as sensitive, it will
930 not be exported by default (see export-options).
933 @opindex keyedit:passwd
934 Change the passphrase of the secret key.
937 @opindex keyedit:toggle
938 This is dummy command which exists only for backward compatibility.
941 @opindex keyedit:clean
942 Compact (by removing all signatures except the selfsig) any user ID
943 that is no longer usable (e.g. revoked, or expired). Then, remove any
944 signatures that are not usable by the trust calculations.
945 Specifically, this removes any signature that does not validate, any
946 signature that is superseded by a later signature, revoked signatures,
947 and signatures issued by keys that are not present on the keyring.
950 @opindex keyedit:minimize
951 Make the key as small as possible. This removes all signatures from
952 each user ID except for the most recent self-signature.
955 @opindex keyedit:cross-certify
956 Add cross-certification signatures to signing subkeys that may not
957 currently have them. Cross-certification signatures protect against a
958 subtle attack against signing subkeys. See
959 @option{--require-cross-certification}. All new keys generated have
960 this signature by default, so this command is only useful to bring
961 older keys up to date.
964 @opindex keyedit:save
965 Save all changes to the keyrings and quit.
968 @opindex keyedit:quit
969 Quit the program without updating the
974 The listing shows you the key with its secondary keys and all user
975 ids. The primary user id is indicated by a dot, and selected keys or
976 user ids are indicated by an asterisk. The trust
977 value is displayed with the primary key: the first is the assigned owner
978 trust and the second is the calculated trust value. Letters are used for
985 No ownertrust assigned / not yet calculated.
989 calculation has failed; probably due to an expired key.
992 Not enough information for calculation.
995 Never trust this key.
1007 @c ******** End Edit-key Options **********
1009 @item --sign-key @code{name}
1011 Signs a public key with your secret key. This is a shortcut version of
1012 the subcommand "sign" from @option{--edit}.
1014 @item --lsign-key @code{name}
1016 Signs a public key with your secret key but marks it as
1017 non-exportable. This is a shortcut version of the subcommand "lsign"
1018 from @option{--edit-key}.
1020 @item --quick-sign-key @code{fpr} [@code{names}]
1021 @itemx --quick-lsign-key @code{fpr} [@code{names}]
1022 @opindex quick-sign-key
1023 @opindex quick-lsign-key
1024 Directly sign a key from the passphrase without any further user
1025 interaction. The @code{fpr} must be the verified primary fingerprint
1026 of a key in the local keyring. If no @code{names} are given, all
1027 useful user ids are signed; with given [@code{names}] only useful user
1028 ids matching one of theses names are signed. By default, or if a name
1029 is prefixed with a '*', a case insensitive substring match is used.
1030 If a name is prefixed with a '=' a case sensitive exact match is done.
1032 The command @option{--quick-lsign-key} marks the signatures as
1033 non-exportable. If such a non-exportable signature already exists the
1034 @option{--quick-sign-key} turns it into a exportable signature.
1036 This command uses reasonable defaults and thus does not provide the
1037 full flexibility of the "sign" subcommand from @option{--edit-key}.
1038 Its intended use is to help unattended key signing by utilizing a list
1039 of verified fingerprints.
1041 @item --quick-adduid @var{user-id} @var{new-user-id}
1042 @opindex quick-adduid
1043 This command adds a new user id to an existing key. In contrast to
1044 the interactive sub-command @code{adduid} of @option{--edit-key} the
1045 @var{new-user-id} is added verbatim with only leading and trailing
1046 white space removed, it is expected to be UTF-8 encoded, and no checks
1047 on its form are applied.
1049 @item --quick-revuid @var{user-id} @var{user-id-to-revoke}
1050 @opindex quick-revuid
1051 This command revokes a User ID on an existing key. It cannot be used
1052 to revoke the last User ID on key (some non-revoked User ID must
1053 remain), with revocation reason ``User ID is no longer valid''. If
1054 you want to specify a different revocation reason, or to supply
1055 supplementary revocation text, you should use the interactive
1056 sub-command @code{revuid} of @option{--edit-key}.
1058 @item --passwd @var{user_id}
1060 Change the passphrase of the secret key belonging to the certificate
1061 specified as @var{user_id}. This is a shortcut for the sub-command
1062 @code{passwd} of the edit key menu.
1067 @c *******************************************
1068 @c *************** ****************
1069 @c *************** OPTIONS ****************
1070 @c *************** ****************
1071 @c *******************************************
1074 @section Option Summary
1076 @command{@gpgname} features a bunch of options to control the exact
1077 behaviour and to change the default configuration.
1080 * GPG Configuration Options:: How to change the configuration.
1081 * GPG Key related Options:: Key related options.
1082 * GPG Input and Output:: Input and Output.
1083 * OpenPGP Options:: OpenPGP protocol specific options.
1084 * Compliance Options:: Compliance options.
1085 * GPG Esoteric Options:: Doing things one usually doesn't want to do.
1086 * Deprecated Options:: Deprecated options.
1089 Long options can be put in an options file (default
1090 "~/.gnupg/gpg.conf"). Short option names will not work - for example,
1091 "armor" is a valid option for the options file, while "a" is not. Do not
1092 write the 2 dashes, but simply the name of the option and any required
1093 arguments. Lines with a hash ('#') as the first non-white-space
1094 character are ignored. Commands may be put in this file too, but that is
1095 not generally useful as the command will execute automatically with
1096 every execution of gpg.
1098 Please remember that option parsing stops as soon as a non-option is
1099 encountered, you can explicitly stop parsing by using the special option
1102 @c *******************************************
1103 @c ******** CONFIGURATION OPTIONS **********
1104 @c *******************************************
1105 @node GPG Configuration Options
1106 @subsection How to change the configuration
1108 These options are used to change the configuration and are usually found
1113 @item --default-key @var{name}
1114 @opindex default-key
1115 Use @var{name} as the default key to sign with. If this option is not
1116 used, the default key is the first key found in the secret keyring.
1117 Note that @option{-u} or @option{--local-user} overrides this option.
1118 This option may be given multiple times. In this case, the last key
1119 for which a secret key is available is used. If there is no secret
1120 key available for any of the specified values, GnuPG will not emit an
1121 error message but continue as if this option wasn't given.
1123 @item --default-recipient @var{name}
1124 @opindex default-recipient
1125 Use @var{name} as default recipient if option @option{--recipient} is
1126 not used and don't ask if this is a valid one. @var{name} must be
1129 @item --default-recipient-self
1130 @opindex default-recipient-self
1131 Use the default key as default recipient if option @option{--recipient} is not
1132 used and don't ask if this is a valid one. The default key is the first
1133 one from the secret keyring or the one set with @option{--default-key}.
1135 @item --no-default-recipient
1136 @opindex no-default-recipient
1137 Reset @option{--default-recipient} and @option{--default-recipient-self}.
1141 Give more information during processing. If used
1142 twice, the input data is listed in detail.
1146 Reset verbose level to 0.
1150 Try to be as quiet as possible.
1156 Use batch mode. Never ask, do not allow interactive commands.
1157 @option{--no-batch} disables this option. Note that even with a
1158 filename given on the command line, gpg might still need to read from
1159 STDIN (in particular if gpg figures that the input is a
1160 detached signature and no data file has been specified). Thus if you
1161 do not want to feed data via STDIN, you should connect STDIN to
1164 It is highly recommended to use this option along with the options
1165 @option{--status-fd} and @option{--with-colons} for any unattended of
1170 Make sure that the TTY (terminal) is never used for any output.
1171 This option is needed in some cases because GnuPG sometimes prints
1172 warnings to the TTY even if @option{--batch} is used.
1176 Assume "yes" on most questions.
1180 Assume "no" on most questions.
1183 @item --list-options @code{parameters}
1184 @opindex list-options
1185 This is a space or comma delimited string that gives options used when
1186 listing keys and signatures (that is, @option{--list-keys},
1187 @option{--list-sigs}, @option{--list-public-keys},
1188 @option{--list-secret-keys}, and the @option{--edit-key} functions).
1189 Options can be prepended with a @option{no-} (after the two dashes) to
1190 give the opposite meaning. The options are:
1195 @opindex list-options:show-photos
1196 Causes @option{--list-keys}, @option{--list-sigs},
1197 @option{--list-public-keys}, and @option{--list-secret-keys} to
1198 display any photo IDs attached to the key. Defaults to no. See also
1199 @option{--photo-viewer}. Does not work with @option{--with-colons}:
1200 see @option{--attribute-fd} for the appropriate way to get photo data
1201 for scripts and other frontends.
1204 @opindex list-options:show-usage
1205 Show usage information for keys and subkeys in the standard key
1206 listing. This is a list of letters indicating the allowed usage for a
1207 key (@code{E}=encryption, @code{S}=signing, @code{C}=certification,
1208 @code{A}=authentication). Defaults to yes.
1210 @item show-policy-urls
1211 @opindex list-options:show-policy-urls
1212 Show policy URLs in the @option{--list-sigs} or @option{--check-sigs}
1213 listings. Defaults to no.
1215 @item show-notations
1216 @itemx show-std-notations
1217 @itemx show-user-notations
1218 @opindex list-options:show-notations
1219 @opindex list-options:show-std-notations
1220 @opindex list-options:show-user-notations
1221 Show all, IETF standard, or user-defined signature notations in the
1222 @option{--list-sigs} or @option{--check-sigs} listings. Defaults to no.
1224 @item show-keyserver-urls
1225 @opindex list-options:show-keyserver-urls
1226 Show any preferred keyserver URL in the @option{--list-sigs} or
1227 @option{--check-sigs} listings. Defaults to no.
1229 @item show-uid-validity
1230 @opindex list-options:show-uid-validity
1231 Display the calculated validity of user IDs during key listings.
1234 @item show-unusable-uids
1235 @opindex list-options:show-unusable-uids
1236 Show revoked and expired user IDs in key listings. Defaults to no.
1238 @item show-unusable-subkeys
1239 @opindex list-options:show-unusable-subkeys
1240 Show revoked and expired subkeys in key listings. Defaults to no.
1243 @opindex list-options:show-keyring
1244 Display the keyring name at the head of key listings to show which
1245 keyring a given key resides on. Defaults to no.
1247 @item show-sig-expire
1248 @opindex list-options:show-sig-expire
1249 Show signature expiration dates (if any) during @option{--list-sigs} or
1250 @option{--check-sigs} listings. Defaults to no.
1252 @item show-sig-subpackets
1253 @opindex list-options:show-sig-subpackets
1254 Include signature subpackets in the key listing. This option can take an
1255 optional argument list of the subpackets to list. If no argument is
1256 passed, list all subpackets. Defaults to no. This option is only
1257 meaningful when using @option{--with-colons} along with
1258 @option{--list-sigs} or @option{--check-sigs}.
1262 @item --verify-options @code{parameters}
1263 @opindex verify-options
1264 This is a space or comma delimited string that gives options used when
1265 verifying signatures. Options can be prepended with a `no-' to give
1266 the opposite meaning. The options are:
1271 @opindex verify-options:show-photos
1272 Display any photo IDs present on the key that issued the signature.
1273 Defaults to no. See also @option{--photo-viewer}.
1275 @item show-policy-urls
1276 @opindex verify-options:show-policy-urls
1277 Show policy URLs in the signature being verified. Defaults to yes.
1279 @item show-notations
1280 @itemx show-std-notations
1281 @itemx show-user-notations
1282 @opindex verify-options:show-notations
1283 @opindex verify-options:show-std-notations
1284 @opindex verify-options:show-user-notations
1285 Show all, IETF standard, or user-defined signature notations in the
1286 signature being verified. Defaults to IETF standard.
1288 @item show-keyserver-urls
1289 @opindex verify-options:show-keyserver-urls
1290 Show any preferred keyserver URL in the signature being verified.
1293 @item show-uid-validity
1294 @opindex verify-options:show-uid-validity
1295 Display the calculated validity of the user IDs on the key that issued
1296 the signature. Defaults to yes.
1298 @item show-unusable-uids
1299 @opindex verify-options:show-unusable-uids
1300 Show revoked and expired user IDs during signature verification.
1303 @item show-primary-uid-only
1304 @opindex verify-options:show-primary-uid-only
1305 Show only the primary user ID during signature verification. That is
1306 all the AKA lines as well as photo Ids are not shown with the signature
1307 verification status.
1310 @opindex verify-options:pka-lookups
1311 Enable PKA lookups to verify sender addresses. Note that PKA is based
1312 on DNS, and so enabling this option may disclose information on when
1313 and what signatures are verified or to whom data is encrypted. This
1314 is similar to the "web bug" described for the @option{--auto-key-retrieve}
1317 @item pka-trust-increase
1318 @opindex verify-options:pka-trust-increase
1319 Raise the trust in a signature to full if the signature passes PKA
1320 validation. This option is only meaningful if pka-lookups is set.
1323 @item --enable-large-rsa
1324 @itemx --disable-large-rsa
1325 @opindex enable-large-rsa
1326 @opindex disable-large-rsa
1327 With --gen-key and --batch, enable the creation of RSA secret keys as
1328 large as 8192 bit. Note: 8192 bit is more than is generally
1329 recommended. These large keys don't significantly improve security,
1330 but they are more expensive to use, and their signatures and
1331 certifications are larger. This option is only available if the
1332 binary was build with large-secmem support.
1335 @itemx --disable-dsa2
1336 @opindex enable-dsa2
1337 @opindex disable-dsa2
1338 Enable hash truncation for all DSA keys even for old DSA Keys up to
1339 1024 bit. This is also the default with @option{--openpgp}. Note
1340 that older versions of GnuPG also required this flag to allow the
1341 generation of DSA larger than 1024 bit.
1343 @item --photo-viewer @code{string}
1344 @opindex photo-viewer
1345 This is the command line that should be run to view a photo ID. "%i"
1346 will be expanded to a filename containing the photo. "%I" does the
1347 same, except the file will not be deleted once the viewer exits.
1348 Other flags are "%k" for the key ID, "%K" for the long key ID, "%f"
1349 for the key fingerprint, "%t" for the extension of the image type
1350 (e.g. "jpg"), "%T" for the MIME type of the image (e.g. "image/jpeg"),
1351 "%v" for the single-character calculated validity of the image being
1352 viewed (e.g. "f"), "%V" for the calculated validity as a string (e.g.
1353 "full"), "%U" for a base32 encoded hash of the user ID,
1354 and "%%" for an actual percent sign. If neither %i or %I are present,
1355 then the photo will be supplied to the viewer on standard input.
1357 The default viewer is "xloadimage -fork -quiet -title 'KeyID 0x%k'
1358 STDIN". Note that if your image viewer program is not secure, then
1359 executing it from GnuPG does not make it secure.
1361 @item --exec-path @code{string}
1364 Sets a list of directories to search for photo viewers and keyserver
1365 helpers. If not provided, keyserver helpers use the compiled-in
1366 default directory, and photo viewers use the @code{PATH} environment
1368 Note, that on W32 system this value is ignored when searching for
1371 @item --keyring @code{file}
1373 Add @code{file} to the current list of keyrings. If @code{file} begins
1374 with a tilde and a slash, these are replaced by the $HOME directory. If
1375 the filename does not contain a slash, it is assumed to be in the GnuPG
1376 home directory ("~/.gnupg" if @option{--homedir} or $GNUPGHOME is not
1379 Note that this adds a keyring to the current list. If the intent is to
1380 use the specified keyring alone, use @option{--keyring} along with
1381 @option{--no-default-keyring}.
1383 If the the option @option{--no-keyring} has been used no keyrings will
1387 @item --secret-keyring @code{file}
1388 @opindex secret-keyring
1389 This is an obsolete option and ignored. All secret keys are stored in
1390 the @file{private-keys-v1.d} directory below the GnuPG home directory.
1392 @item --primary-keyring @code{file}
1393 @opindex primary-keyring
1394 Designate @code{file} as the primary public keyring. This means that
1395 newly imported keys (via @option{--import} or keyserver
1396 @option{--recv-from}) will go to this keyring.
1398 @item --trustdb-name @code{file}
1399 @opindex trustdb-name
1400 Use @code{file} instead of the default trustdb. If @code{file} begins
1401 with a tilde and a slash, these are replaced by the $HOME directory. If
1402 the filename does not contain a slash, it is assumed to be in the GnuPG
1403 home directory (@file{~/.gnupg} if @option{--homedir} or $GNUPGHOME is
1406 @include opt-homedir.texi
1409 @item --display-charset @code{name}
1410 @opindex display-charset
1411 Set the name of the native character set. This is used to convert
1412 some informational strings like user IDs to the proper UTF-8 encoding.
1413 Note that this has nothing to do with the character set of data to be
1414 encrypted or signed; GnuPG does not recode user-supplied data. If
1415 this option is not used, the default character set is determined from
1416 the current locale. A verbosity level of 3 shows the chosen set.
1417 Valid values for @code{name} are:
1422 @opindex display-charset:iso-8859-1
1423 This is the Latin 1 set.
1426 @opindex display-charset:iso-8859-2
1430 @opindex display-charset:iso-8859-15
1431 This is currently an alias for
1435 @opindex display-charset:koi8-r
1436 The usual Russian set (RFC-1489).
1439 @opindex display-charset:utf-8
1440 Bypass all translations and assume
1441 that the OS uses native UTF-8 encoding.
1444 @item --utf8-strings
1445 @itemx --no-utf8-strings
1446 @opindex utf8-strings
1447 Assume that command line arguments are given as UTF-8 strings. The
1448 default (@option{--no-utf8-strings}) is to assume that arguments are
1449 encoded in the character set as specified by
1450 @option{--display-charset}. These options affect all following
1451 arguments. Both options may be used multiple times.
1453 @anchor{gpg-option --options}
1454 @item --options @code{file}
1456 Read options from @code{file} and do not try to read them from the
1457 default options file in the homedir (see @option{--homedir}). This
1458 option is ignored if used in an options file.
1462 Shortcut for @option{--options /dev/null}. This option is detected
1463 before an attempt to open an option file. Using this option will also
1464 prevent the creation of a @file{~/.gnupg} homedir.
1467 @itemx --compress-level @code{n}
1468 @itemx --bzip2-compress-level @code{n}
1469 @opindex compress-level
1470 @opindex bzip2-compress-level
1471 Set compression level to @code{n} for the ZIP and ZLIB compression
1472 algorithms. The default is to use the default compression level of zlib
1473 (normally 6). @option{--bzip2-compress-level} sets the compression level
1474 for the BZIP2 compression algorithm (defaulting to 6 as well). This is a
1475 different option from @option{--compress-level} since BZIP2 uses a
1476 significant amount of memory for each additional compression level.
1477 @option{-z} sets both. A value of 0 for @code{n} disables compression.
1479 @item --bzip2-decompress-lowmem
1480 @opindex bzip2-decompress-lowmem
1481 Use a different decompression method for BZIP2 compressed files. This
1482 alternate method uses a bit more than half the memory, but also runs
1483 at half the speed. This is useful under extreme low memory
1484 circumstances when the file was originally compressed at a high
1485 @option{--bzip2-compress-level}.
1488 @item --mangle-dos-filenames
1489 @itemx --no-mangle-dos-filenames
1490 @opindex mangle-dos-filenames
1491 @opindex no-mangle-dos-filenames
1492 Older version of Windows cannot handle filenames with more than one
1493 dot. @option{--mangle-dos-filenames} causes GnuPG to replace (rather
1494 than add to) the extension of an output filename to avoid this
1495 problem. This option is off by default and has no effect on non-Windows
1498 @item --ask-cert-level
1499 @itemx --no-ask-cert-level
1500 @opindex ask-cert-level
1501 When making a key signature, prompt for a certification level. If this
1502 option is not specified, the certification level used is set via
1503 @option{--default-cert-level}. See @option{--default-cert-level} for
1504 information on the specific levels and how they are
1505 used. @option{--no-ask-cert-level} disables this option. This option
1508 @item --default-cert-level @code{n}
1509 @opindex default-cert-level
1510 The default to use for the check level when signing a key.
1512 0 means you make no particular claim as to how carefully you verified
1515 1 means you believe the key is owned by the person who claims to own
1516 it but you could not, or did not verify the key at all. This is
1517 useful for a "persona" verification, where you sign the key of a
1520 2 means you did casual verification of the key. For example, this
1521 could mean that you verified the key fingerprint and checked the
1522 user ID on the key against a photo ID.
1524 3 means you did extensive verification of the key. For example, this
1525 could mean that you verified the key fingerprint with the owner of the
1526 key in person, and that you checked, by means of a hard to forge
1527 document with a photo ID (such as a passport) that the name of the key
1528 owner matches the name in the user ID on the key, and finally that you
1529 verified (by exchange of email) that the email address on the key
1530 belongs to the key owner.
1532 Note that the examples given above for levels 2 and 3 are just that:
1533 examples. In the end, it is up to you to decide just what "casual"
1534 and "extensive" mean to you.
1536 This option defaults to 0 (no particular claim).
1538 @item --min-cert-level
1539 @opindex min-cert-level
1540 When building the trust database, treat any signatures with a
1541 certification level below this as invalid. Defaults to 2, which
1542 disregards level 1 signatures. Note that level 0 "no particular
1543 claim" signatures are always accepted.
1545 @item --trusted-key @code{long key ID}
1546 @opindex trusted-key
1547 Assume that the specified key (which must be given
1548 as a full 8 byte key ID) is as trustworthy as one of
1549 your own secret keys. This option is useful if you
1550 don't want to keep your secret keys (or one of them)
1551 online but still want to be able to check the validity of a given
1552 recipient's or signator's key.
1554 @item --trust-model @code{pgp|classic|tofu|tofu+pgp|direct|always|auto}
1555 @opindex trust-model
1556 Set what trust model GnuPG should follow. The models are:
1561 @opindex trust-mode:pgp
1562 This is the Web of Trust combined with trust signatures as used in PGP
1563 5.x and later. This is the default trust model when creating a new
1567 @opindex trust-mode:classic
1568 This is the standard Web of Trust as introduced by PGP 2.
1571 @opindex trust-mode:tofu
1572 @anchor{trust-model-tofu}
1573 TOFU stands for Trust On First Use. In this trust model, the first
1574 time a key is seen, it is memorized. If later another key is seen
1575 with a user id with the same email address, a warning is displayed
1576 indicating that there is a conflict and that the key might be a
1577 forgery and an attempt at a man-in-the-middle attack.
1579 Because a potential attacker is able to control the email address
1580 and thereby circumvent the conflict detection algorithm by using an
1581 email address that is similar in appearance to a trusted email
1582 address, whenever a message is verified, statistics about the number
1583 of messages signed with the key are shown. In this way, a user can
1584 easily identify attacks using fake keys for regular correspondents.
1586 When compared with the Web of Trust, TOFU offers significantly
1587 weaker security guarantees. In particular, TOFU only helps ensure
1588 consistency (that is, that the binding between a key and email
1589 address doesn't change). A major advantage of TOFU is that it
1590 requires little maintenance to use correctly. To use the web of
1591 trust properly, you need to actively sign keys and mark users as
1592 trusted introducers. This is a time-consuming process and anecdotal
1593 evidence suggests that even security-conscious users rarely take the
1594 time to do this thoroughly and instead rely on an ad-hoc TOFU
1597 In the TOFU model, policies are associated with bindings between
1598 keys and email addresses (which are extracted from user ids and
1599 normalized). There are five policies, which can be set manually
1600 using the @option{--tofu-policy} option. The default policy can be
1601 set using the @option{--tofu-default-policy} option.
1603 The TOFU policies are: @code{auto}, @code{good}, @code{unknown},
1604 @code{bad} and @code{ask}. The @code{auto} policy is used by
1605 default (unless overridden by @option{--tofu-default-policy}) and
1606 marks a binding as marginally trusted. The @code{good},
1607 @code{unknown} and @code{bad} policies mark a binding as fully
1608 trusted, as having unknown trust or as having trust never,
1609 respectively. The @code{unknown} policy is useful for just using
1610 TOFU to detect conflicts, but to never assign positive trust to a
1611 binding. The final policy, @code{ask} prompts the user to indicate
1612 the binding's trust. If batch mode is enabled (or input is
1613 inappropriate in the context), then the user is not prompted and the
1614 @code{undefined} trust level is returned.
1617 @opindex trust-mode:tofu+pgp
1618 This trust model combines TOFU with the Web of Trust. This is done
1619 by computing the trust level for each model and then taking the
1620 maximum trust level where the trust levels are ordered as follows:
1621 @code{unknown < undefined < marginal < fully < ultimate < expired <
1624 By setting @option{--tofu-default-policy=unknown}, this model can be
1625 used to implement the web of trust with TOFU's conflict detection
1626 algorithm, but without its assignment of positive trust values,
1627 which some security-conscious users don't like.
1630 @opindex trust-mode:direct
1631 Key validity is set directly by the user and not calculated via the
1635 @opindex trust-mode:always
1636 Skip key validation and assume that used keys are always fully
1637 valid. You generally won't use this unless you are using some
1638 external validation scheme. This option also suppresses the
1639 "[uncertain]" tag printed with signature checks when there is no
1640 evidence that the user ID is bound to the key. Note that this
1641 trust model still does not allow the use of expired, revoked, or
1645 @opindex trust-mode:auto
1646 Select the trust model depending on whatever the internal trust
1647 database says. This is the default model if such a database already
1651 @item --auto-key-locate @code{parameters}
1652 @itemx --no-auto-key-locate
1653 @opindex auto-key-locate
1654 GnuPG can automatically locate and retrieve keys as needed using this
1655 option. This happens when encrypting to an email address (in the
1656 "user@@example.com" form), and there are no user@@example.com keys on
1657 the local keyring. This option takes any number of the following
1658 mechanisms, in the order they are to be tried:
1663 Locate a key using DNS CERT, as specified in RFC-4398.
1666 Locate a key using DNS PKA.
1669 Locate a key using DANE, as specified
1670 in draft-ietf-dane-openpgpkey-05.txt.
1673 Locate a key using the Web Key Directory protocol.
1674 This is an experimental method and semantics may change.
1677 Using DNS Service Discovery, check the domain in question for any LDAP
1678 keyservers to use. If this fails, attempt to locate the key using the
1679 PGP Universal method of checking @samp{ldap://keys.(thedomain)}.
1682 Locate a key using whatever keyserver is defined using the
1683 @option{--keyserver} option.
1686 In addition, a keyserver URL as used in the @option{--keyserver} option
1687 may be used here to query that particular keyserver.
1690 Locate the key using the local keyrings. This mechanism allows the user to
1691 select the order a local key lookup is done. Thus using
1692 @samp{--auto-key-locate local} is identical to
1693 @option{--no-auto-key-locate}.
1696 This flag disables the standard local key lookup, done before any of the
1697 mechanisms defined by the @option{--auto-key-locate} are tried. The
1698 position of this mechanism in the list does not matter. It is not
1699 required if @code{local} is also used.
1702 Clear all defined mechanisms. This is useful to override
1703 mechanisms given in a config file.
1707 @item --auto-key-retrieve
1708 @itemx --no-auto-key-retrieve
1709 @opindex auto-key-retrieve
1710 @opindex no-auto-key-retrieve
1711 This option enables the automatic retrieving of keys from a keyserver
1712 when verifying signatures made by keys that are not on the local
1715 If the method "wkd" is included in the list of methods given to
1716 @option{auto-key-locate}, the Signer's User ID is part of the
1717 signature, and the option @option{--disable-signer-uid} is not used,
1718 the "wkd" method may also be used to retrieve a key.
1720 Note that this option makes a "web bug" like behavior possible.
1721 Keyserver or Web Key Directory operators can see which keys you
1722 request, so by sending you a message signed by a brand new key (which
1723 you naturally will not have on your local keyring), the operator can
1724 tell both your IP address and the time when you verified the
1727 @item --keyid-format @code{none|short|0xshort|long|0xlong}
1728 @opindex keyid-format
1729 Select how to display key IDs. "none" does not show the key ID at all
1730 but shows the fingerprint in a separate line. "short" is the
1731 traditional 8-character key ID. "long" is the more accurate (but less
1732 convenient) 16-character key ID. Add an "0x" to either to include an
1733 "0x" at the beginning of the key ID, as in 0x99242560. Note that this
1734 option is ignored if the option @option{--with-colons} is used.
1736 @item --keyserver @code{name}
1738 This option is deprecated - please use the @option{--keyserver} in
1739 @file{dirmngr.conf} instead.
1741 Use @code{name} as your keyserver. This is the server that
1742 @option{--recv-keys}, @option{--send-keys}, and @option{--search-keys}
1743 will communicate with to receive keys from, send keys to, and search for
1744 keys on. The format of the @code{name} is a URI:
1745 `scheme:[//]keyservername[:port]' The scheme is the type of keyserver:
1746 "hkp" for the HTTP (or compatible) keyservers, "ldap" for the LDAP
1747 keyservers, or "mailto" for the Graff email keyserver. Note that your
1748 particular installation of GnuPG may have other keyserver types
1749 available as well. Keyserver schemes are case-insensitive. After the
1750 keyserver name, optional keyserver configuration options may be
1751 provided. These are the same as the global @option{--keyserver-options}
1752 from below, but apply only to this particular keyserver.
1754 Most keyservers synchronize with each other, so there is generally no
1755 need to send keys to more than one server. The keyserver
1756 @code{hkp://keys.gnupg.net} uses round robin DNS to give a different
1757 keyserver each time you use it.
1759 @item --keyserver-options @code{name=value}
1760 @opindex keyserver-options
1761 This is a space or comma delimited string that gives options for the
1762 keyserver. Options can be prefixed with a `no-' to give the opposite
1763 meaning. Valid import-options or export-options may be used here as
1764 well to apply to importing (@option{--recv-key}) or exporting
1765 (@option{--send-key}) a key from a keyserver. While not all options
1766 are available for all keyserver types, some common options are:
1770 @item include-revoked
1771 When searching for a key with @option{--search-keys}, include keys that
1772 are marked on the keyserver as revoked. Note that not all keyservers
1773 differentiate between revoked and unrevoked keys, and for such
1774 keyservers this option is meaningless. Note also that most keyservers do
1775 not have cryptographic verification of key revocations, and so turning
1776 this option off may result in skipping keys that are incorrectly marked
1779 @item include-disabled
1780 When searching for a key with @option{--search-keys}, include keys that
1781 are marked on the keyserver as disabled. Note that this option is not
1782 used with HKP keyservers.
1784 @item auto-key-retrieve
1785 This is the same as the option @option{auto-key-retrieve}.
1787 @item honor-keyserver-url
1788 When using @option{--refresh-keys}, if the key in question has a preferred
1789 keyserver URL, then use that preferred keyserver to refresh the key
1790 from. In addition, if auto-key-retrieve is set, and the signature
1791 being verified has a preferred keyserver URL, then use that preferred
1792 keyserver to fetch the key from. Note that this option introduces a
1793 "web bug": The creator of the key can see when the keys is
1794 refreshed. Thus this option is not enabled by default.
1796 @item honor-pka-record
1797 If @option{--auto-key-retrieve} is used, and the signature being
1798 verified has a PKA record, then use the PKA information to fetch
1799 the key. Defaults to "yes".
1801 @item include-subkeys
1802 When receiving a key, include subkeys as potential targets. Note that
1803 this option is not used with HKP keyservers, as they do not support
1804 retrieving keys by subkey id.
1807 Tell the keyserver helper program how long (in seconds) to try and
1808 perform a keyserver action before giving up. Note that performing
1809 multiple actions at the same time uses this timeout value per action.
1810 For example, when retrieving multiple keys via @option{--recv-keys}, the
1811 timeout applies separately to each key retrieval, and not to the
1812 @option{--recv-keys} command as a whole. Defaults to 30 seconds.
1814 @item http-proxy=@code{value}
1815 This option is deprecated.
1816 Set the proxy to use for HTTP and HKP keyservers.
1817 This overrides any proxy defined in @file{dirmngr.conf}.
1820 This option has no more function since GnuPG 2.1. Use the
1821 @code{dirmngr} configuration options instead.
1824 This option has no more function since GnuPG 2.1. Use the
1825 @code{dirmngr} configuration options instead.
1828 This option has no more function since GnuPG 2.1. Use the
1829 @code{dirmngr} configuration options instead.
1832 This option has no more function since GnuPG 2.1. Use the
1833 @code{dirmngr} configuration options instead.
1837 @item --completes-needed @code{n}
1838 @opindex compliant-needed
1839 Number of completely trusted users to introduce a new
1840 key signer (defaults to 1).
1842 @item --marginals-needed @code{n}
1843 @opindex marginals-needed
1844 Number of marginally trusted users to introduce a new
1845 key signer (defaults to 3)
1847 @item --tofu-default-policy @code{auto|good|unknown|bad|ask}
1848 @opindex tofu-default-policy
1849 The default TOFU policy (defaults to @code{auto}). For more
1850 information about the meaning of this option, @pxref{trust-model-tofu}.
1852 @item --max-cert-depth @code{n}
1853 @opindex max-cert-depth
1854 Maximum depth of a certification chain (default is 5).
1856 @item --no-sig-cache
1857 @opindex no-sig-cache
1858 Do not cache the verification status of key signatures.
1859 Caching gives a much better performance in key listings. However, if
1860 you suspect that your public keyring is not safe against write
1861 modifications, you can use this option to disable the caching. It
1862 probably does not make sense to disable it because all kind of damage
1863 can be done if someone else has write access to your public keyring.
1865 @item --auto-check-trustdb
1866 @itemx --no-auto-check-trustdb
1867 @opindex auto-check-trustdb
1868 If GnuPG feels that its information about the Web of Trust has to be
1869 updated, it automatically runs the @option{--check-trustdb} command
1870 internally. This may be a time consuming
1871 process. @option{--no-auto-check-trustdb} disables this option.
1874 @itemx --no-use-agent
1876 This is dummy option. @command{@gpgname} always requires the agent.
1878 @item --gpg-agent-info
1879 @opindex gpg-agent-info
1880 This is dummy option. It has no effect when used with @command{@gpgname}.
1883 @item --agent-program @var{file}
1884 @opindex agent-program
1885 Specify an agent program to be used for secret key operations. The
1886 default value is determined by running @command{gpgconf} with the
1887 option @option{--list-dirs}. Note that the pipe symbol (@code{|}) is
1888 used for a regression test suite hack and may thus not be used in the
1891 @item --dirmngr-program @var{file}
1892 @opindex dirmngr-program
1893 Specify a dirmngr program to be used for keyserver access. The
1894 default value is @file{@value{BINDIR}/dirmngr}.
1896 @item --no-autostart
1897 @opindex no-autostart
1898 Do not start the gpg-agent or the dirmngr if it has not yet been
1899 started and its service is required. This option is mostly useful on
1900 machines where the connection to gpg-agent has been redirected to
1901 another machines. If dirmngr is required on the remote machine, it
1902 may be started manually using @command{gpgconf --launch dirmngr}.
1906 Lock the databases the first time a lock is requested
1907 and do not release the lock until the process
1910 @item --lock-multiple
1911 @opindex lock-multiple
1912 Release the locks every time a lock is no longer
1913 needed. Use this to override a previous @option{--lock-once}
1918 Disable locking entirely. This option should be used only in very
1919 special environments, where it can be assured that only one process
1920 is accessing those files. A bootable floppy with a stand-alone
1921 encryption system will probably use this. Improper usage of this
1922 option may lead to data and key corruption.
1924 @item --exit-on-status-write-error
1925 @opindex exit-on-status-write-error
1926 This option will cause write errors on the status FD to immediately
1927 terminate the process. That should in fact be the default but it never
1928 worked this way and thus we need an option to enable this, so that the
1929 change won't break applications which close their end of a status fd
1930 connected pipe too early. Using this option along with
1931 @option{--enable-progress-filter} may be used to cleanly cancel long
1932 running gpg operations.
1934 @item --limit-card-insert-tries @code{n}
1935 @opindex limit-card-insert-tries
1936 With @code{n} greater than 0 the number of prompts asking to insert a
1937 smartcard gets limited to N-1. Thus with a value of 1 gpg won't at
1938 all ask to insert a card if none has been inserted at startup. This
1939 option is useful in the configuration file in case an application does
1940 not know about the smartcard support and waits ad infinitum for an
1943 @item --no-random-seed-file
1944 @opindex no-random-seed-file
1945 GnuPG uses a file to store its internal random pool over invocations.
1946 This makes random generation faster; however sometimes write operations
1947 are not desired. This option can be used to achieve that with the cost of
1948 slower random generation.
1951 @opindex no-greeting
1952 Suppress the initial copyright message.
1954 @item --no-secmem-warning
1955 @opindex no-secmem-warning
1956 Suppress the warning about "using insecure memory".
1958 @item --no-permission-warning
1959 @opindex permission-warning
1960 Suppress the warning about unsafe file and home directory (@option{--homedir})
1961 permissions. Note that the permission checks that GnuPG performs are
1962 not intended to be authoritative, but rather they simply warn about
1963 certain common permission problems. Do not assume that the lack of a
1964 warning means that your system is secure.
1966 Note that the warning for unsafe @option{--homedir} permissions cannot be
1967 suppressed in the gpg.conf file, as this would allow an attacker to
1968 place an unsafe gpg.conf file in place, and use this file to suppress
1969 warnings about itself. The @option{--homedir} permissions warning may only be
1970 suppressed on the command line.
1972 @item --no-mdc-warning
1973 @opindex no-mdc-warning
1974 Suppress the warning about missing MDC integrity protection.
1976 @item --require-secmem
1977 @itemx --no-require-secmem
1978 @opindex require-secmem
1979 Refuse to run if GnuPG cannot get secure memory. Defaults to no
1980 (i.e. run, but give a warning).
1983 @item --require-cross-certification
1984 @itemx --no-require-cross-certification
1985 @opindex require-cross-certification
1986 When verifying a signature made from a subkey, ensure that the cross
1987 certification "back signature" on the subkey is present and valid. This
1988 protects against a subtle attack against subkeys that can sign.
1989 Defaults to @option{--require-cross-certification} for
1995 Allow the user to do certain nonsensical or "silly" things like
1996 signing an expired or revoked key, or certain potentially incompatible
1997 things like generating unusual key types. This also disables certain
1998 warning messages about potentially incompatible actions. As the name
1999 implies, this option is for experts only. If you don't fully
2000 understand the implications of what it allows you to do, leave this
2001 off. @option{--no-expert} disables this option.
2006 @c *******************************************
2007 @c ******** KEY RELATED OPTIONS ************
2008 @c *******************************************
2009 @node GPG Key related Options
2010 @subsection Key related options
2014 @item --recipient @var{name}
2017 Encrypt for user id @var{name}. If this option or
2018 @option{--hidden-recipient} is not specified, GnuPG asks for the user-id
2019 unless @option{--default-recipient} is given.
2021 @item --hidden-recipient @var{name}
2023 @opindex hidden-recipient
2024 Encrypt for user ID @var{name}, but hide the key ID of this user's
2025 key. This option helps to hide the receiver of the message and is a
2026 limited countermeasure against traffic analysis. If this option or
2027 @option{--recipient} is not specified, GnuPG asks for the user ID unless
2028 @option{--default-recipient} is given.
2030 @item --recipient-file @var{file}
2032 @opindex recipient-file
2033 This option is similar to @option{--recipient} except that it
2034 encrypts to a key stored in the given file. @var{file} must be the
2035 name of a file containing exactly one key. @command{gpg} assumes that
2036 the key in this file is fully valid.
2038 @item --hidden-recipient-file @var{file}
2040 @opindex hidden-recipient-file
2041 This option is similar to @option{--hidden-recipient} except that it
2042 encrypts to a key stored in the given file. @var{file} must be the
2043 name of a file containing exactly one key. @command{gpg} assumes that
2044 the key in this file is fully valid.
2046 @item --encrypt-to @code{name}
2048 Same as @option{--recipient} but this one is intended for use in the
2049 options file and may be used with your own user-id as an
2050 "encrypt-to-self". These keys are only used when there are other
2051 recipients given either by use of @option{--recipient} or by the asked
2052 user id. No trust checking is performed for these user ids and even
2053 disabled keys can be used.
2055 @item --hidden-encrypt-to @code{name}
2056 @opindex hidden-encrypt-to
2057 Same as @option{--hidden-recipient} but this one is intended for use in the
2058 options file and may be used with your own user-id as a hidden
2059 "encrypt-to-self". These keys are only used when there are other
2060 recipients given either by use of @option{--recipient} or by the asked user id.
2061 No trust checking is performed for these user ids and even disabled
2064 @item --no-encrypt-to
2065 @opindex no-encrypt-to
2066 Disable the use of all @option{--encrypt-to} and
2067 @option{--hidden-encrypt-to} keys.
2069 @item --group @code{name=value}
2071 Sets up a named group, which is similar to aliases in email programs.
2072 Any time the group name is a recipient (@option{-r} or
2073 @option{--recipient}), it will be expanded to the values
2074 specified. Multiple groups with the same name are automatically merged
2075 into a single group.
2077 The values are @code{key IDs} or fingerprints, but any key description
2078 is accepted. Note that a value with spaces in it will be treated as
2079 two different values. Note also there is only one level of expansion
2080 --- you cannot make an group that points to another group. When used
2081 from the command line, it may be necessary to quote the argument to
2082 this option to prevent the shell from treating it as multiple
2085 @item --ungroup @code{name}
2087 Remove a given entry from the @option{--group} list.
2091 Remove all entries from the @option{--group} list.
2093 @item --local-user @var{name}
2096 Use @var{name} as the key to sign with. Note that this option overrides
2097 @option{--default-key}.
2099 @item --sender @var{mbox}
2101 This option has two purposes. @var{mbox} must either be a complete
2102 user id with a proper mail address or just a mail address. When
2103 creating a signature this option tells gpg the user id of a key used
2104 to make a signature if the key was not directly specified by a user
2105 id. When verifying a signature the @var{mbox} is used to restrict the
2106 information printed by the TOFU code to matching user ids.
2108 @item --try-secret-key @var{name}
2109 @opindex try-secret-key
2110 For hidden recipients GPG needs to know the keys to use for trial
2111 decryption. The key set with @option{--default-key} is always tried
2112 first, but this is often not sufficient. This option allows setting more
2113 keys to be used for trial decryption. Although any valid user-id
2114 specification may be used for @var{name} it makes sense to use at least
2115 the long keyid to avoid ambiguities. Note that gpg-agent might pop up a
2116 pinentry for a lot keys to do the trial decryption. If you want to stop
2117 all further trial decryption you may use close-window button instead of
2120 @item --try-all-secrets
2121 @opindex try-all-secrets
2122 Don't look at the key ID as stored in the message but try all secret
2123 keys in turn to find the right decryption key. This option forces the
2124 behaviour as used by anonymous recipients (created by using
2125 @option{--throw-keyids} or @option{--hidden-recipient}) and might come
2126 handy in case where an encrypted message contains a bogus key ID.
2128 @item --skip-hidden-recipients
2129 @itemx --no-skip-hidden-recipients
2130 @opindex skip-hidden-recipients
2131 @opindex no-skip-hidden-recipients
2132 During decryption skip all anonymous recipients. This option helps in
2133 the case that people use the hidden recipients feature to hide there
2134 own encrypt-to key from others. If oneself has many secret keys this
2135 may lead to a major annoyance because all keys are tried in turn to
2136 decrypt something which was not really intended for it. The drawback
2137 of this option is that it is currently not possible to decrypt a
2138 message which includes real anonymous recipients.
2143 @c *******************************************
2144 @c ******** INPUT AND OUTPUT ***************
2145 @c *******************************************
2146 @node GPG Input and Output
2147 @subsection Input and Output
2154 Create ASCII armored output. The default is to create the binary
2159 Assume the input data is not in ASCII armored format.
2161 @item --output @var{file}
2162 @itemx -o @var{file}
2164 Write output to @var{file}. To write to stdout use @code{-} as the
2167 @item --max-output @code{n}
2169 This option sets a limit on the number of bytes that will be generated
2170 when processing a file. Since OpenPGP supports various levels of
2171 compression, it is possible that the plaintext of a given message may be
2172 significantly larger than the original OpenPGP message. While GnuPG
2173 works properly with such messages, there is often a desire to set a
2174 maximum file size that will be generated before processing is forced to
2175 stop by the OS limits. Defaults to 0, which means "no limit".
2177 @item --input-size-hint @var{n}
2178 @opindex input-size-hint
2179 This option can be used to tell GPG the size of the input data in
2180 bytes. @var{n} must be a positive base-10 number. This option is
2181 only useful if the input is not taken from a file. GPG may use this
2182 hint to optimize its buffer allocation strategy. It is also used by
2183 the @option{--status-fd} line ``PROGRESS'' to provide a value for
2184 ``total'' if that is not available by other means.
2186 @item --import-options @code{parameters}
2187 @opindex import-options
2188 This is a space or comma delimited string that gives options for
2189 importing keys. Options can be prepended with a `no-' to give the
2190 opposite meaning. The options are:
2194 @item import-local-sigs
2195 Allow importing key signatures marked as "local". This is not
2196 generally useful unless a shared keyring scheme is being used.
2199 @item keep-ownertrust
2200 Normally possible still existing ownertrust values of a key are
2201 cleared if a key is imported. This is in general desirable so that
2202 a formerly deleted key does not automatically gain an ownertrust
2203 values merely due to import. On the other hand it is sometimes
2204 necessary to re-import a trusted set of keys again but keeping
2205 already assigned ownertrust values. This can be achieved by using
2208 @item repair-pks-subkey-bug
2209 During import, attempt to repair the damage caused by the PKS keyserver
2210 bug (pre version 0.9.6) that mangles keys with multiple subkeys. Note
2211 that this cannot completely repair the damaged key as some crucial data
2212 is removed by the keyserver, but it does at least give you back one
2213 subkey. Defaults to no for regular @option{--import} and to yes for
2214 keyserver @option{--recv-keys}.
2217 Show a listing of the key as imported right before it is stored.
2218 This can be combined with the option @option{--dry-run} to only look
2222 Run the entire import code but instead of storing the key to the
2223 local keyring write it to the output. The export options
2224 @option{export-pka} and @option{export-dane} affect the output. This
2225 option can be used to remove all invalid parts from a key without the
2229 During import, allow key updates to existing keys, but do not allow
2230 any new keys to be imported. Defaults to no.
2233 After import, compact (remove all signatures except the
2234 self-signature) any user IDs from the new key that are not usable.
2235 Then, remove any signatures from the new key that are not usable.
2236 This includes signatures that were issued by keys that are not present
2237 on the keyring. This option is the same as running the @option{--edit-key}
2238 command "clean" after import. Defaults to no.
2240 @item import-minimal
2241 Import the smallest key possible. This removes all signatures except
2242 the most recent self-signature on each user ID. This option is the
2243 same as running the @option{--edit-key} command "minimize" after import.
2247 @item --import-filter @code{@var{name}=@var{expr}}
2248 @itemx --export-filter @code{@var{name}=@var{expr}}
2249 @opindex import-filter
2250 @opindex export-filter
2251 These options define an import/export filter which are applied to the
2252 imported/exported keyblock right before it will be stored/written.
2253 @var{name} defines the type of filter to use, @var{expr} the
2254 expression to evaluate. The option can be used several times which
2255 then appends more expression to the same @var{name}.
2258 The available filter types are:
2263 This filter will keep a user id packet and its dependent packets in
2264 the keyblock if the expression evaluates to true.
2267 This filter drops the selected subkeys.
2268 Currently only implemented for --export-filter.
2271 This filter drops the selected key signatures on user ids.
2272 Self-signatures are not considered.
2273 Currently only implemented for --import-filter.
2277 For the syntax of the expression see the chapter "FILTER EXPRESSIONS".
2278 The property names for the expressions depend on the actual filter
2279 type and are indicated in the following table.
2281 The available properties are:
2286 A string with the user id. (keep-uid)
2289 The addr-spec part of a user id with mailbox or the empty string.
2293 A number with the public key algorithm of a key or subkey packet.
2297 @itemx key_created_d
2298 The first is the timestamp a public key or subkey packet was
2299 created. The second is the same but given as an ISO string,
2300 e.g. "2016-08-17". (drop-subkey)
2303 Boolean indicating whether the user id is the primary one. (keep-uid)
2306 Boolean indicating whether a key or subkey is a secret one.
2310 @itemx sig_created_d
2311 The first is the timestamp a signature packet was created. The
2312 second is the same but given as an ISO string,
2313 e.g. "2016-08-17". (drop-sig)
2316 A number with the public key algorithm of a signature packet. (drop-sig)
2318 @item sig_digest_algo
2319 A number with the digest algorithm of a signature packet. (drop-sig)
2323 @item --export-options @code{parameters}
2324 @opindex export-options
2325 This is a space or comma delimited string that gives options for
2326 exporting keys. Options can be prepended with a `no-' to give the
2327 opposite meaning. The options are:
2331 @item export-local-sigs
2332 Allow exporting key signatures marked as "local". This is not
2333 generally useful unless a shared keyring scheme is being used.
2336 @item export-attributes
2337 Include attribute user IDs (photo IDs) while exporting. This is
2338 useful to export keys if they are going to be used by an OpenPGP
2339 program that does not accept attribute user IDs. Defaults to yes.
2341 @item export-sensitive-revkeys
2342 Include designated revoker information that was marked as
2343 "sensitive". Defaults to no.
2345 @c Since GnuPG 2.1 gpg-agent manages the secret key and thus the
2346 @c export-reset-subkey-passwd hack is not anymore justified. Such use
2347 @c cases may be implemented using a specialized secret key export
2349 @c @item export-reset-subkey-passwd
2350 @c When using the @option{--export-secret-subkeys} command, this option resets
2351 @c the passphrases for all exported subkeys to empty. This is useful
2352 @c when the exported subkey is to be used on an unattended machine where
2353 @c a passphrase doesn't necessarily make sense. Defaults to no.
2356 Compact (remove all signatures from) user IDs on the key being
2357 exported if the user IDs are not usable. Also, do not export any
2358 signatures that are not usable. This includes signatures that were
2359 issued by keys that are not present on the keyring. This option is
2360 the same as running the @option{--edit-key} command "clean" before export
2361 except that the local copy of the key is not modified. Defaults to
2364 @item export-minimal
2365 Export the smallest key possible. This removes all signatures except the
2366 most recent self-signature on each user ID. This option is the same as
2367 running the @option{--edit-key} command "minimize" before export except
2368 that the local copy of the key is not modified. Defaults to no.
2371 Instead of outputting the key material output PKA records suitable
2372 to put into DNS zone files. An ORIGIN line is printed before each
2373 record to allow diverting the records to the corresponding zone file.
2376 Instead of outputting the key material output OpenPGP DANE records
2377 suitable to put into DNS zone files. An ORIGIN line is printed before
2378 each record to allow diverting the records to the corresponding zone
2384 @opindex with-colons
2385 Print key listings delimited by colons. Note that the output will be
2386 encoded in UTF-8 regardless of any @option{--display-charset} setting. This
2387 format is useful when GnuPG is called from scripts and other programs
2388 as it is easily machine parsed. The details of this format are
2389 documented in the file @file{doc/DETAILS}, which is included in the GnuPG
2390 source distribution.
2392 @item --fixed-list-mode
2393 @opindex fixed-list-mode
2394 Do not merge primary user ID and primary key in @option{--with-colon}
2395 listing mode and print all timestamps as seconds since 1970-01-01.
2396 Since GnuPG 2.0.10, this mode is always used and thus this option is
2397 obsolete; it does not harm to use it though.
2399 @item --legacy-list-mode
2400 @opindex legacy-list-mode
2401 Revert to the pre-2.1 public key list mode. This only affects the
2402 human readable output and not the machine interface
2403 (i.e. @code{--with-colons}). Note that the legacy format does not
2404 convey suitable information for elliptic curves.
2406 @item --with-fingerprint
2407 @opindex with-fingerprint
2408 Same as the command @option{--fingerprint} but changes only the format
2409 of the output and may be used together with another command.
2411 @item --with-subkey-fingerprint
2412 @opindex with-subkey-fingerprint
2413 If a fingerprint is printed for the primary key, this option forces
2414 printing of the fingerprint for all subkeys. This could also be
2415 achieved by using the @option{--with-fingerprint} twice but by using
2416 this option along with keyid-format "none" a compact fingerprint is
2419 @item --with-icao-spelling
2420 @opindex with-icao-spelling
2421 Print the ICAO spelling of the fingerprint in addition to the hex digits.
2423 @item --with-keygrip
2424 @opindex with-keygrip
2425 Include the keygrip in the key listings. In @code{--with-colons} mode
2426 this is implicitly enable for secret keys.
2428 @item --with-wkd-hash
2429 @opindex with-wkd-hash
2430 Print a Web Key Directory identifier along with each user ID in key
2431 listings. This is an experimental feature and semantics may change.
2434 @opindex with-secret
2435 Include info about the presence of a secret key in public key listings
2436 done with @code{--with-colons}.
2440 @c *******************************************
2441 @c ******** OPENPGP OPTIONS ****************
2442 @c *******************************************
2443 @node OpenPGP Options
2444 @subsection OpenPGP protocol specific options
2448 @item -t, --textmode
2449 @itemx --no-textmode
2451 Treat input files as text and store them in the OpenPGP canonical text
2452 form with standard "CRLF" line endings. This also sets the necessary
2453 flags to inform the recipient that the encrypted or signed data is text
2454 and may need its line endings converted back to whatever the local
2455 system uses. This option is useful when communicating between two
2456 platforms that have different line ending conventions (UNIX-like to Mac,
2457 Mac to Windows, etc). @option{--no-textmode} disables this option, and
2460 @item --force-v3-sigs
2461 @itemx --no-force-v3-sigs
2462 @item --force-v4-certs
2463 @itemx --no-force-v4-certs
2464 These options are obsolete and have no effect since GnuPG 2.1.
2468 Force the use of encryption with a modification detection code. This
2469 is always used with the newer ciphers (those with a blocksize greater
2470 than 64 bits), or if all of the recipient keys indicate MDC support in
2471 their feature flags.
2474 @opindex disable-mdc
2475 Disable the use of the modification detection code. Note that by
2476 using this option, the encrypted message becomes vulnerable to a
2477 message modification attack.
2479 @item --disable-signer-uid
2480 @opindex disable-signer-uid
2481 By default the user ID of the signing key is embedded in the data
2482 signature. As of now this is only done if the signing key has been
2483 specified with @option{local-user} using a mail address. This
2484 information can be helpful for verifier to locate the key; see
2485 option @option{--auto-key-retrieve}.
2487 @item --personal-cipher-preferences @code{string}
2488 @opindex personal-cipher-preferences
2489 Set the list of personal cipher preferences to @code{string}. Use
2490 @command{@gpgname --version} to get a list of available algorithms,
2491 and use @code{none} to set no preference at all. This allows the user
2492 to safely override the algorithm chosen by the recipient key
2493 preferences, as GPG will only select an algorithm that is usable by
2494 all recipients. The most highly ranked cipher in this list is also
2495 used for the @option{--symmetric} encryption command.
2497 @item --personal-digest-preferences @code{string}
2498 @opindex personal-digest-preferences
2499 Set the list of personal digest preferences to @code{string}. Use
2500 @command{@gpgname --version} to get a list of available algorithms,
2501 and use @code{none} to set no preference at all. This allows the user
2502 to safely override the algorithm chosen by the recipient key
2503 preferences, as GPG will only select an algorithm that is usable by
2504 all recipients. The most highly ranked digest algorithm in this list
2505 is also used when signing without encryption
2506 (e.g. @option{--clearsign} or @option{--sign}).
2508 @item --personal-compress-preferences @code{string}
2509 @opindex personal-compress-preferences
2510 Set the list of personal compression preferences to @code{string}.
2511 Use @command{@gpgname --version} to get a list of available
2512 algorithms, and use @code{none} to set no preference at all. This
2513 allows the user to safely override the algorithm chosen by the
2514 recipient key preferences, as GPG will only select an algorithm that
2515 is usable by all recipients. The most highly ranked compression
2516 algorithm in this list is also used when there are no recipient keys
2517 to consider (e.g. @option{--symmetric}).
2519 @item --s2k-cipher-algo @code{name}
2520 @opindex s2k-cipher-algo
2521 Use @code{name} as the cipher algorithm for symmetric encryption with
2522 a passphrase if @option{--personal-cipher-preferences} and
2523 @option{--cipher-algo} are not given. The default is @value{GPGSYMENCALGO}.
2525 @item --s2k-digest-algo @code{name}
2526 @opindex s2k-digest-algo
2527 Use @code{name} as the digest algorithm used to mangle the passphrases
2528 for symmetric encryption. The default is SHA-1.
2530 @item --s2k-mode @code{n}
2532 Selects how passphrases for symmetric encryption are mangled. If
2533 @code{n} is 0 a plain passphrase (which is in general not recommended)
2534 will be used, a 1 adds a salt (which should not be used) to the
2535 passphrase and a 3 (the default) iterates the whole process a number
2536 of times (see @option{--s2k-count}).
2538 @item --s2k-count @code{n}
2540 Specify how many times the passphrases mangling for symmetric
2541 encryption is repeated. This value may range between 1024 and
2542 65011712 inclusive. The default is inquired from gpg-agent. Note
2543 that not all values in the 1024-65011712 range are legal and if an
2544 illegal value is selected, GnuPG will round up to the nearest legal
2545 value. This option is only meaningful if @option{--s2k-mode} is set
2546 to the default of 3.
2551 @c ***************************
2552 @c ******* Compliance ********
2553 @c ***************************
2554 @node Compliance Options
2555 @subsection Compliance options
2557 These options control what GnuPG is compliant to. Only one of these
2558 options may be active at a time. Note that the default setting of
2559 this is nearly always the correct one. See the INTEROPERABILITY WITH
2560 OTHER OPENPGP PROGRAMS section below before using one of these
2567 Use standard GnuPG behavior. This is essentially OpenPGP behavior
2568 (see @option{--openpgp}), but with some additional workarounds for common
2569 compatibility problems in different versions of PGP. This is the
2570 default option, so it is not generally needed, but it may be useful to
2571 override a different compliance option in the gpg.conf file.
2575 Reset all packet, cipher and digest options to strict OpenPGP
2576 behavior. Use this option to reset all previous options like
2577 @option{--s2k-*}, @option{--cipher-algo}, @option{--digest-algo} and
2578 @option{--compress-algo} to OpenPGP compliant values. All PGP
2579 workarounds are disabled.
2583 Reset all packet, cipher and digest options to strict RFC-4880
2584 behavior. Note that this is currently the same thing as
2589 Enable experimental features from proposed updates to RFC-4880. This
2590 option can be used in addition to the other compliance options.
2591 Warning: The behavior may change with any GnuPG release and created
2592 keys or data may not be usable with future GnuPG versions.
2596 Reset all packet, cipher and digest options to strict RFC-2440
2601 Set up all options to be as PGP 6 compliant as possible. This
2602 restricts you to the ciphers IDEA (if the IDEA plugin is installed),
2603 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160, and the
2604 compression algorithms none and ZIP. This also disables
2605 @option{--throw-keyids}, and making signatures with signing subkeys as PGP 6
2606 does not understand signatures made by signing subkeys.
2608 This option implies @option{--disable-mdc --escape-from-lines}.
2612 Set up all options to be as PGP 7 compliant as possible. This is
2613 identical to @option{--pgp6} except that MDCs are not disabled, and the
2614 list of allowable ciphers is expanded to add AES128, AES192, AES256, and
2619 Set up all options to be as PGP 8 compliant as possible. PGP 8 is a lot
2620 closer to the OpenPGP standard than previous versions of PGP, so all
2621 this does is disable @option{--throw-keyids} and set
2622 @option{--escape-from-lines}. All algorithms are allowed except for the
2623 SHA224, SHA384, and SHA512 digests.
2625 @item --compliance @var{string}
2627 This option can be used instead of one of the options above. Valid
2628 values for @var{string} are the above option names (without the double
2629 dash) and possibly others as shown when using "help" for @var{value}.
2634 @c *******************************************
2635 @c ******** ESOTERIC OPTIONS ***************
2636 @c *******************************************
2637 @node GPG Esoteric Options
2638 @subsection Doing things one usually doesn't want to do
2645 Don't make any changes (this is not completely implemented).
2649 Changes the behaviour of some commands. This is like @option{--dry-run} but
2650 different in some cases. The semantic of this option may be extended in
2651 the future. Currently it only skips the actual decryption pass and
2652 therefore enables a fast listing of the encryption keys.
2655 @itemx --interactive
2656 @opindex interactive
2657 Prompt before overwriting any files.
2659 @item --debug-level @var{level}
2660 @opindex debug-level
2661 Select the debug level for investigating problems. @var{level} may be
2662 a numeric value or by a keyword:
2666 No debugging at all. A value of less than 1 may be used instead of
2669 Some basic debug messages. A value between 1 and 2 may be used
2670 instead of the keyword.
2672 More verbose debug messages. A value between 3 and 5 may be used
2673 instead of the keyword.
2675 Even more detailed messages. A value between 6 and 8 may be used
2676 instead of the keyword.
2678 All of the debug messages you can get. A value greater than 8 may be
2679 used instead of the keyword. The creation of hash tracing files is
2680 only enabled if the keyword is used.
2683 How these messages are mapped to the actual debugging flags is not
2684 specified and may change with newer releases of this program. They are
2685 however carefully selected to best aid in debugging.
2687 @item --debug @var{flags}
2689 Set debugging flags. All flags are or-ed and @var{flags} may be given
2690 in C syntax (e.g. 0x0042) or as a comma separated list of flag names.
2691 To get a list of all supported flags the single word "help" can be
2696 Set all useful debugging flags.
2699 @opindex debug-iolbf
2700 Set stdout into line buffered mode. This option is only honored when
2701 given on the command line.
2703 @item --faked-system-time @var{epoch}
2704 @opindex faked-system-time
2705 This option is only useful for testing; it sets the system time back or
2706 forth to @var{epoch} which is the number of seconds elapsed since the year
2707 1970. Alternatively @var{epoch} may be given as a full ISO time string
2708 (e.g. "20070924T154812").
2710 @item --enable-progress-filter
2711 @opindex enable-progress-filter
2712 Enable certain PROGRESS status outputs. This option allows frontends
2713 to display a progress indicator while gpg is processing larger files.
2714 There is a slight performance overhead using it.
2716 @item --status-fd @code{n}
2718 Write special status strings to the file descriptor @code{n}.
2719 See the file DETAILS in the documentation for a listing of them.
2721 @item --status-file @code{file}
2722 @opindex status-file
2723 Same as @option{--status-fd}, except the status data is written to file
2726 @item --logger-fd @code{n}
2728 Write log output to file descriptor @code{n} and not to STDERR.
2730 @item --log-file @code{file}
2731 @itemx --logger-file @code{file}
2733 Same as @option{--logger-fd}, except the logger data is written to
2734 file @code{file}. Use @file{socket://} to log to socket.
2736 @item --attribute-fd @code{n}
2737 @opindex attribute-fd
2738 Write attribute subpackets to the file descriptor @code{n}. This is most
2739 useful for use with @option{--status-fd}, since the status messages are
2740 needed to separate out the various subpackets from the stream delivered
2741 to the file descriptor.
2743 @item --attribute-file @code{file}
2744 @opindex attribute-file
2745 Same as @option{--attribute-fd}, except the attribute data is written to
2748 @item --comment @code{string}
2749 @itemx --no-comments
2751 Use @code{string} as a comment string in clear text signatures and ASCII
2752 armored messages or keys (see @option{--armor}). The default behavior is
2753 not to use a comment string. @option{--comment} may be repeated multiple
2754 times to get multiple comment strings. @option{--no-comments} removes
2755 all comments. It is a good idea to keep the length of a single comment
2756 below 60 characters to avoid problems with mail programs wrapping such
2757 lines. Note that comment lines, like all other header lines, are not
2758 protected by the signature.
2760 @item --emit-version
2761 @itemx --no-emit-version
2762 @opindex emit-version
2763 Force inclusion of the version string in ASCII armored output. If
2764 given once only the name of the program and the major number is
2765 emitted, given twice the minor is also emitted, given thrice
2766 the micro is added, and given four times an operating system identification
2767 is also emitted. @option{--no-emit-version} (default) disables the version
2770 @item --sig-notation @code{name=value}
2771 @itemx --cert-notation @code{name=value}
2772 @itemx -N, --set-notation @code{name=value}
2773 @opindex sig-notation
2774 @opindex cert-notation
2775 @opindex set-notation
2776 Put the name value pair into the signature as notation data.
2777 @code{name} must consist only of printable characters or spaces, and
2778 must contain a '@@' character in the form keyname@@domain.example.com
2779 (substituting the appropriate keyname and domain name, of course). This
2780 is to help prevent pollution of the IETF reserved notation
2781 namespace. The @option{--expert} flag overrides the '@@'
2782 check. @code{value} may be any printable string; it will be encoded in
2783 UTF-8, so you should check that your @option{--display-charset} is set
2784 correctly. If you prefix @code{name} with an exclamation mark (!), the
2785 notation data will be flagged as critical
2786 (rfc4880:5.2.3.16). @option{--sig-notation} sets a notation for data
2787 signatures. @option{--cert-notation} sets a notation for key signatures
2788 (certifications). @option{--set-notation} sets both.
2790 There are special codes that may be used in notation names. "%k" will
2791 be expanded into the key ID of the key being signed, "%K" into the
2792 long key ID of the key being signed, "%f" into the fingerprint of the
2793 key being signed, "%s" into the key ID of the key making the
2794 signature, "%S" into the long key ID of the key making the signature,
2795 "%g" into the fingerprint of the key making the signature (which might
2796 be a subkey), "%p" into the fingerprint of the primary key of the key
2797 making the signature, "%c" into the signature count from the OpenPGP
2798 smartcard, and "%%" results in a single "%". %k, %K, and %f are only
2799 meaningful when making a key signature (certification), and %c is only
2800 meaningful when using the OpenPGP smartcard.
2802 @item --sig-policy-url @code{string}
2803 @itemx --cert-policy-url @code{string}
2804 @itemx --set-policy-url @code{string}
2805 @opindex sig-policy-url
2806 @opindex cert-policy-url
2807 @opindex set-policy-url
2808 Use @code{string} as a Policy URL for signatures (rfc4880:5.2.3.20). If
2809 you prefix it with an exclamation mark (!), the policy URL packet will
2810 be flagged as critical. @option{--sig-policy-url} sets a policy url for
2811 data signatures. @option{--cert-policy-url} sets a policy url for key
2812 signatures (certifications). @option{--set-policy-url} sets both.
2814 The same %-expandos used for notation data are available here as well.
2816 @item --sig-keyserver-url @code{string}
2817 @opindex sig-keyserver-url
2818 Use @code{string} as a preferred keyserver URL for data signatures. If
2819 you prefix it with an exclamation mark (!), the keyserver URL packet
2820 will be flagged as critical.
2822 The same %-expandos used for notation data are available here as well.
2824 @item --set-filename @code{string}
2825 @opindex set-filename
2826 Use @code{string} as the filename which is stored inside messages.
2827 This overrides the default, which is to use the actual filename of the
2828 file being encrypted. Using the empty string for @code{string}
2829 effectively removes the filename from the output.
2831 @item --for-your-eyes-only
2832 @itemx --no-for-your-eyes-only
2833 @opindex for-your-eyes-only
2834 Set the `for your eyes only' flag in the message. This causes GnuPG to
2835 refuse to save the file unless the @option{--output} option is given,
2836 and PGP to use a "secure viewer" with a claimed Tempest-resistant font
2837 to display the message. This option overrides @option{--set-filename}.
2838 @option{--no-for-your-eyes-only} disables this option.
2840 @item --use-embedded-filename
2841 @itemx --no-use-embedded-filename
2842 @opindex use-embedded-filename
2843 Try to create a file with a name as embedded in the data. This can be
2844 a dangerous option as it enables overwriting files. Defaults to no.
2846 @item --cipher-algo @code{name}
2847 @opindex cipher-algo
2848 Use @code{name} as cipher algorithm. Running the program with the
2849 command @option{--version} yields a list of supported algorithms. If
2850 this is not used the cipher algorithm is selected from the preferences
2851 stored with the key. In general, you do not want to use this option as
2852 it allows you to violate the OpenPGP standard.
2853 @option{--personal-cipher-preferences} is the safe way to accomplish the
2856 @item --digest-algo @code{name}
2857 @opindex digest-algo
2858 Use @code{name} as the message digest algorithm. Running the program
2859 with the command @option{--version} yields a list of supported algorithms. In
2860 general, you do not want to use this option as it allows you to
2861 violate the OpenPGP standard. @option{--personal-digest-preferences} is the
2862 safe way to accomplish the same thing.
2864 @item --compress-algo @code{name}
2865 @opindex compress-algo
2866 Use compression algorithm @code{name}. "zlib" is RFC-1950 ZLIB
2867 compression. "zip" is RFC-1951 ZIP compression which is used by PGP.
2868 "bzip2" is a more modern compression scheme that can compress some
2869 things better than zip or zlib, but at the cost of more memory used
2870 during compression and decompression. "uncompressed" or "none"
2871 disables compression. If this option is not used, the default
2872 behavior is to examine the recipient key preferences to see which
2873 algorithms the recipient supports. If all else fails, ZIP is used for
2874 maximum compatibility.
2876 ZLIB may give better compression results than ZIP, as the compression
2877 window size is not limited to 8k. BZIP2 may give even better
2878 compression results than that, but will use a significantly larger
2879 amount of memory while compressing and decompressing. This may be
2880 significant in low memory situations. Note, however, that PGP (all
2881 versions) only supports ZIP compression. Using any algorithm other
2882 than ZIP or "none" will make the message unreadable with PGP. In
2883 general, you do not want to use this option as it allows you to
2884 violate the OpenPGP standard. @option{--personal-compress-preferences} is the
2885 safe way to accomplish the same thing.
2887 @item --cert-digest-algo @code{name}
2888 @opindex cert-digest-algo
2889 Use @code{name} as the message digest algorithm used when signing a
2890 key. Running the program with the command @option{--version} yields a
2891 list of supported algorithms. Be aware that if you choose an algorithm
2892 that GnuPG supports but other OpenPGP implementations do not, then some
2893 users will not be able to use the key signatures you make, or quite
2894 possibly your entire key.
2896 @item --disable-cipher-algo @code{name}
2897 @opindex disable-cipher-algo
2898 Never allow the use of @code{name} as cipher algorithm.
2899 The given name will not be checked so that a later loaded algorithm
2900 will still get disabled.
2902 @item --disable-pubkey-algo @code{name}
2903 @opindex disable-pubkey-algo
2904 Never allow the use of @code{name} as public key algorithm.
2905 The given name will not be checked so that a later loaded algorithm
2906 will still get disabled.
2908 @item --throw-keyids
2909 @itemx --no-throw-keyids
2910 @opindex throw-keyids
2911 Do not put the recipient key IDs into encrypted messages. This helps to
2912 hide the receivers of the message and is a limited countermeasure
2913 against traffic analysis.@footnote{Using a little social engineering
2914 anyone who is able to decrypt the message can check whether one of the
2915 other recipients is the one he suspects.} On the receiving side, it may
2916 slow down the decryption process because all available secret keys must
2917 be tried. @option{--no-throw-keyids} disables this option. This option
2918 is essentially the same as using @option{--hidden-recipient} for all
2921 @item --not-dash-escaped
2922 @opindex not-dash-escaped
2923 This option changes the behavior of cleartext signatures
2924 so that they can be used for patch files. You should not
2925 send such an armored file via email because all spaces
2926 and line endings are hashed too. You can not use this
2927 option for data which has 5 dashes at the beginning of a
2928 line, patch files don't have this. A special armor header
2929 line tells GnuPG about this cleartext signature option.
2931 @item --escape-from-lines
2932 @itemx --no-escape-from-lines
2933 @opindex escape-from-lines
2934 Because some mailers change lines starting with "From " to ">From " it
2935 is good to handle such lines in a special way when creating cleartext
2936 signatures to prevent the mail system from breaking the signature. Note
2937 that all other PGP versions do it this way too. Enabled by
2938 default. @option{--no-escape-from-lines} disables this option.
2940 @item --passphrase-repeat @code{n}
2941 @opindex passphrase-repeat
2942 Specify how many times @command{@gpgname} will request a new
2943 passphrase be repeated. This is useful for helping memorize a
2944 passphrase. Defaults to 1 repetition.
2946 @item --passphrase-fd @code{n}
2947 @opindex passphrase-fd
2948 Read the passphrase from file descriptor @code{n}. Only the first line
2949 will be read from file descriptor @code{n}. If you use 0 for @code{n},
2950 the passphrase will be read from STDIN. This can only be used if only
2951 one passphrase is supplied.
2953 Note that this passphrase is only used if the option @option{--batch}
2954 has also been given. This is different from GnuPG version 1.x.
2956 @item --passphrase-file @code{file}
2957 @opindex passphrase-file
2958 Read the passphrase from file @code{file}. Only the first line will
2959 be read from file @code{file}. This can only be used if only one
2960 passphrase is supplied. Obviously, a passphrase stored in a file is
2961 of questionable security if other users can read this file. Don't use
2962 this option if you can avoid it.
2963 Note that this passphrase is only used if the option @option{--batch}
2964 has also been given. This is different from GnuPG version 1.x.
2966 @item --passphrase @code{string}
2968 Use @code{string} as the passphrase. This can only be used if only one
2969 passphrase is supplied. Obviously, this is of very questionable
2970 security on a multi-user system. Don't use this option if you can
2972 Note that this passphrase is only used if the option @option{--batch}
2973 has also been given. This is different from GnuPG version 1.x.
2975 @item --pinentry-mode @code{mode}
2976 @opindex pinentry-mode
2977 Set the pinentry mode to @code{mode}. Allowed values for @code{mode}
2981 Use the default of the agent, which is @code{ask}.
2983 Force the use of the Pinentry.
2985 Emulate use of Pinentry's cancel button.
2987 Return a Pinentry error (``No Pinentry'').
2989 Redirect Pinentry queries to the caller. Note that in contrast to
2990 Pinentry the user is not prompted again if he enters a bad password.
2993 @item --command-fd @code{n}
2995 This is a replacement for the deprecated shared-memory IPC mode.
2996 If this option is enabled, user input on questions is not expected
2997 from the TTY but from the given file descriptor. It should be used
2998 together with @option{--status-fd}. See the file doc/DETAILS in the source
2999 distribution for details on how to use it.
3001 @item --command-file @code{file}
3002 @opindex command-file
3003 Same as @option{--command-fd}, except the commands are read out of file
3006 @item --allow-non-selfsigned-uid
3007 @itemx --no-allow-non-selfsigned-uid
3008 @opindex allow-non-selfsigned-uid
3009 Allow the import and use of keys with user IDs which are not
3010 self-signed. This is not recommended, as a non self-signed user ID is
3011 trivial to forge. @option{--no-allow-non-selfsigned-uid} disables.
3013 @item --allow-freeform-uid
3014 @opindex allow-freeform-uid
3015 Disable all checks on the form of the user ID while generating a new
3016 one. This option should only be used in very special environments as
3017 it does not ensure the de-facto standard format of user IDs.
3019 @item --ignore-time-conflict
3020 @opindex ignore-time-conflict
3021 GnuPG normally checks that the timestamps associated with keys and
3022 signatures have plausible values. However, sometimes a signature
3023 seems to be older than the key due to clock problems. This option
3024 makes these checks just a warning. See also @option{--ignore-valid-from} for
3025 timestamp issues on subkeys.
3027 @item --ignore-valid-from
3028 @opindex ignore-valid-from
3029 GnuPG normally does not select and use subkeys created in the future.
3030 This option allows the use of such keys and thus exhibits the
3031 pre-1.0.7 behaviour. You should not use this option unless there
3032 is some clock problem. See also @option{--ignore-time-conflict} for timestamp
3033 issues with signatures.
3035 @item --ignore-crc-error
3036 @opindex ignore-crc-error
3037 The ASCII armor used by OpenPGP is protected by a CRC checksum against
3038 transmission errors. Occasionally the CRC gets mangled somewhere on
3039 the transmission channel but the actual content (which is protected by
3040 the OpenPGP protocol anyway) is still okay. This option allows GnuPG
3041 to ignore CRC errors.
3043 @item --ignore-mdc-error
3044 @opindex ignore-mdc-error
3045 This option changes a MDC integrity protection failure into a warning.
3046 This can be useful if a message is partially corrupt, but it is
3047 necessary to get as much data as possible out of the corrupt message.
3048 However, be aware that a MDC protection failure may also mean that the
3049 message was tampered with intentionally by an attacker.
3051 @item --allow-weak-digest-algos
3052 @opindex allow-weak-digest-algos
3053 Signatures made with known-weak digest algorithms are normally
3054 rejected with an ``invalid digest algorithm'' message. This option
3055 allows the verification of signatures made with such weak algorithms.
3056 MD5 is the only digest algorithm considered weak by default. See also
3057 @option{--weak-digest} to reject other digest algorithms.
3059 @item --weak-digest @code{name}
3060 @opindex weak-digest
3061 Treat the specified digest algorithm as weak. Signatures made over
3062 weak digests algorithms are normally rejected. This option can be
3063 supplied multiple times if multiple algorithms should be considered
3064 weak. See also @option{--allow-weak-digest-algos} to disable
3065 rejection of weak digests. MD5 is always considered weak, and does
3066 not need to be listed explicitly.
3068 @item --no-default-keyring
3069 @opindex no-default-keyring
3070 Do not add the default keyrings to the list of keyrings. Note that
3071 GnuPG will not operate without any keyrings, so if you use this option
3072 and do not provide alternate keyrings via @option{--keyring} or
3073 @option{--secret-keyring}, then GnuPG will still use the default public or
3078 Do not add use any keyrings even if specified as options.
3081 @opindex skip-verify
3082 Skip the signature verification step. This may be
3083 used to make the decryption faster if the signature
3084 verification is not needed.
3086 @item --with-key-data
3087 @opindex with-key-data
3088 Print key listings delimited by colons (like @option{--with-colons}) and
3089 print the public key data.
3091 @item --fast-list-mode
3092 @opindex fast-list-mode
3093 Changes the output of the list commands to work faster; this is achieved
3094 by leaving some parts empty. Some applications don't need the user ID
3095 and the trust information given in the listings. By using this options
3096 they can get a faster listing. The exact behaviour of this option may
3097 change in future versions. If you are missing some information, don't
3102 This is not for normal use. Use the source to see for what it might be useful.
3104 @item --set-filesize
3105 @opindex set-filesize
3106 This is not for normal use. Use the source to see for what it might be useful.
3108 @item --show-session-key
3109 @opindex show-session-key
3110 Display the session key used for one message. See
3111 @option{--override-session-key} for the counterpart of this option.
3113 We think that Key Escrow is a Bad Thing; however the user should have
3114 the freedom to decide whether to go to prison or to reveal the content
3115 of one specific message without compromising all messages ever
3116 encrypted for one secret key.
3118 You can also use this option if you receive an encrypted message which
3119 is abusive or offensive, to prove to the administrators of the
3120 messaging system that the ciphertext transmitted corresponds to an
3121 inappropriate plaintext so they can take action against the offending
3124 @item --override-session-key @code{string}
3125 @itemx --override-session-key-fd @code{fd}
3126 @opindex override-session-key
3127 Don't use the public key but the session key @code{string} respective
3128 the session key taken from the first line read from file descriptor
3129 @code{fd}. The format of this string is the same as the one printed
3130 by @option{--show-session-key}. This option is normally not used but
3131 comes handy in case someone forces you to reveal the content of an
3132 encrypted message; using this option you can do this without handing
3133 out the secret key. Note that using @option{--override-session-key}
3134 may reveal the session key to all local users via the global process
3137 @item --ask-sig-expire
3138 @itemx --no-ask-sig-expire
3139 @opindex ask-sig-expire
3140 When making a data signature, prompt for an expiration time. If this
3141 option is not specified, the expiration time set via
3142 @option{--default-sig-expire} is used. @option{--no-ask-sig-expire}
3143 disables this option.
3145 @item --default-sig-expire
3146 @opindex default-sig-expire
3147 The default expiration time to use for signature expiration. Valid
3148 values are "0" for no expiration, a number followed by the letter d
3149 (for days), w (for weeks), m (for months), or y (for years) (for
3150 example "2m" for two months, or "5y" for five years), or an absolute
3151 date in the form YYYY-MM-DD. Defaults to "0".
3153 @item --ask-cert-expire
3154 @itemx --no-ask-cert-expire
3155 @opindex ask-cert-expire
3156 When making a key signature, prompt for an expiration time. If this
3157 option is not specified, the expiration time set via
3158 @option{--default-cert-expire} is used. @option{--no-ask-cert-expire}
3159 disables this option.
3161 @item --default-cert-expire
3162 @opindex default-cert-expire
3163 The default expiration time to use for key signature expiration.
3164 Valid values are "0" for no expiration, a number followed by the
3165 letter d (for days), w (for weeks), m (for months), or y (for years)
3166 (for example "2m" for two months, or "5y" for five years), or an
3167 absolute date in the form YYYY-MM-DD. Defaults to "0".
3169 @item --default-new-key-algo @var{string}
3170 @opindex default-new-key-algo @var{string}
3171 This option can be used to change the default algorithms for key
3172 generation. Note that the advanced key generation commands can always
3173 be used to specify a key algorithm directly. Please consult the
3174 source code to learn the syntax of @var{string}.
3176 @item --allow-secret-key-import
3177 @opindex allow-secret-key-import
3178 This is an obsolete option and is not used anywhere.
3180 @item --allow-multiple-messages
3181 @item --no-allow-multiple-messages
3182 @opindex allow-multiple-messages
3183 Allow processing of multiple OpenPGP messages contained in a single file
3184 or stream. Some programs that call GPG are not prepared to deal with
3185 multiple messages being processed together, so this option defaults to
3186 no. Note that versions of GPG prior to 1.4.7 always allowed multiple
3189 Warning: Do not use this option unless you need it as a temporary
3193 @item --enable-special-filenames
3194 @opindex enable-special-filenames
3195 This option enables a mode in which filenames of the form
3196 @file{-&n}, where n is a non-negative decimal number,
3197 refer to the file descriptor n and not to a file with that name.
3199 @item --no-expensive-trust-checks
3200 @opindex no-expensive-trust-checks
3201 Experimental use only.
3203 @item --preserve-permissions
3204 @opindex preserve-permissions
3205 Don't change the permissions of a secret keyring back to user
3206 read/write only. Use this option only if you really know what you are doing.
3208 @item --default-preference-list @code{string}
3209 @opindex default-preference-list
3210 Set the list of default preferences to @code{string}. This preference
3211 list is used for new keys and becomes the default for "setpref" in the
3214 @item --default-keyserver-url @code{name}
3215 @opindex default-keyserver-url
3216 Set the default keyserver URL to @code{name}. This keyserver will be
3217 used as the keyserver URL when writing a new self-signature on a key,
3218 which includes key generation and changing preferences.
3221 @opindex list-config
3222 Display various internal configuration parameters of GnuPG. This option
3223 is intended for external programs that call GnuPG to perform tasks, and
3224 is thus not generally useful. See the file @file{doc/DETAILS} in the
3225 source distribution for the details of which configuration items may be
3226 listed. @option{--list-config} is only usable with
3227 @option{--with-colons} set.
3229 @item --list-gcrypt-config
3230 @opindex list-gcrypt-config
3231 Display various internal configuration parameters of Libgcrypt.
3233 @item --gpgconf-list
3234 @opindex gpgconf-list
3235 This command is similar to @option{--list-config} but in general only
3236 internally used by the @command{gpgconf} tool.
3238 @item --gpgconf-test
3239 @opindex gpgconf-test
3240 This is more or less dummy action. However it parses the configuration
3241 file and returns with failure if the configuration file would prevent
3242 @command{gpg} from startup. Thus it may be used to run a syntax check
3243 on the configuration file.
3247 @c *******************************
3248 @c ******* Deprecated ************
3249 @c *******************************
3250 @node Deprecated Options
3251 @subsection Deprecated options
3256 @itemx --no-show-photos
3257 @opindex show-photos
3258 Causes @option{--list-keys}, @option{--list-sigs},
3259 @option{--list-public-keys}, @option{--list-secret-keys}, and verifying
3260 a signature to also display the photo ID attached to the key, if
3261 any. See also @option{--photo-viewer}. These options are deprecated. Use
3262 @option{--list-options [no-]show-photos} and/or @option{--verify-options
3263 [no-]show-photos} instead.
3265 @item --show-keyring
3266 @opindex show-keyring
3267 Display the keyring name at the head of key listings to show which
3268 keyring a given key resides on. This option is deprecated: use
3269 @option{--list-options [no-]show-keyring} instead.
3271 @item --always-trust
3272 @opindex always-trust
3273 Identical to @option{--trust-model always}. This option is deprecated.
3275 @item --show-notation
3276 @itemx --no-show-notation
3277 @opindex show-notation
3278 Show signature notations in the @option{--list-sigs} or @option{--check-sigs} listings
3279 as well as when verifying a signature with a notation in it. These
3280 options are deprecated. Use @option{--list-options [no-]show-notation}
3281 and/or @option{--verify-options [no-]show-notation} instead.
3283 @item --show-policy-url
3284 @itemx --no-show-policy-url
3285 @opindex show-policy-url
3286 Show policy URLs in the @option{--list-sigs} or @option{--check-sigs}
3287 listings as well as when verifying a signature with a policy URL in
3288 it. These options are deprecated. Use @option{--list-options
3289 [no-]show-policy-url} and/or @option{--verify-options
3290 [no-]show-policy-url} instead.
3296 @c *******************************************
3297 @c *************** ****************
3298 @c *************** FILES ****************
3299 @c *************** ****************
3300 @c *******************************************
3302 @node GPG Configuration
3303 @section Configuration files
3305 There are a few configuration files to control certain aspects of
3306 @command{@gpgname}'s operation. Unless noted, they are expected in the
3307 current home directory (@pxref{option --homedir}).
3313 This is the standard configuration file read by @command{@gpgname} on
3314 startup. It may contain any valid long option; the leading two dashes
3315 may not be entered and the option may not be abbreviated. This default
3316 name may be changed on the command line (@pxref{gpg-option --options}).
3317 You should backup this file.
3321 Note that on larger installations, it is useful to put predefined files
3322 into the directory @file{@value{SYSCONFSKELDIR}} so that
3323 newly created users start up with a working configuration.
3324 For existing users a small
3325 helper script is provided to create these files (@pxref{addgnupghome}).
3327 For internal purposes @command{@gpgname} creates and maintains a few other
3328 files; They all live in in the current home directory (@pxref{option
3329 --homedir}). Only the @command{@gpgname} program may modify these files.
3335 This is the default home directory which is used if neither the
3336 environment variable @code{GNUPGHOME} nor the option
3337 @option{--homedir} is given.
3339 @item ~/.gnupg/pubring.gpg
3340 @efindex pubring.gpg
3341 The public keyring. You should backup this file.
3343 @item ~/.gnupg/pubring.gpg.lock
3344 The lock file for the public keyring.
3346 @item ~/.gnupg/pubring.kbx
3347 @efindex pubring.kbx
3348 The public keyring using a different format. This file is shared
3349 with @command{gpgsm}. You should backup this file.
3351 @item ~/.gnupg/pubring.kbx.lock
3352 The lock file for @file{pubring.kbx}.
3354 @item ~/.gnupg/secring.gpg
3355 @efindex secring.gpg
3356 A secret keyring as used by GnuPG versions before 2.1. It is not
3357 used by GnuPG 2.1 and later.
3359 @item ~/.gnupg/secring.gpg.lock
3360 The lock file for the secret keyring.
3362 @item ~/.gnupg/.gpg-v21-migrated
3363 @efindex .gpg-v21-migrated
3364 File indicating that a migration to GnuPG 2.1 has been done.
3366 @item ~/.gnupg/trustdb.gpg
3367 @efindex trustdb.gpg
3368 The trust database. There is no need to backup this file; it is better
3369 to backup the ownertrust values (@pxref{option --export-ownertrust}).
3371 @item ~/.gnupg/trustdb.gpg.lock
3372 The lock file for the trust database.
3374 @item ~/.gnupg/random_seed
3375 @efindex random_seed
3376 A file used to preserve the state of the internal random pool.
3378 @item ~/.gnupg/openpgp-revocs.d/
3379 @efindex openpgp-revocs.d
3380 This is the directory where gpg stores pre-generated revocation
3381 certificates. The file name corresponds to the OpenPGP fingerprint of
3382 the respective key. It is suggested to backup those certificates and
3383 if the primary private key is not stored on the disk to move them to
3384 an external storage device. Anyone who can access theses files is
3385 able to revoke the corresponding key. You may want to print them out.
3386 You should backup all files in this directory and take care to keep
3387 this backup closed away.
3389 @item @value{DATADIR}/options.skel
3390 @efindex options.skel
3391 The skeleton options file.
3395 Operation is further controlled by a few environment variables:
3401 Used to locate the default home directory.
3405 If set directory used instead of "~/.gnupg".
3407 @item GPG_AGENT_INFO
3408 This variable is obsolete; it was used by GnuPG versions before 2.1.
3410 @item PINENTRY_USER_DATA
3411 @efindex PINENTRY_USER_DATA
3412 This value is passed via gpg-agent to pinentry. It is useful to convey
3413 extra information to a custom pinentry.
3419 Used to size some displays to the full size of the screen.
3423 Apart from its use by GNU, it is used in the W32 version to override the
3424 language selection done through the Registry. If used and set to a
3425 valid and available language name (@var{langid}), the file with the
3426 translation is loaded from
3427 @code{@var{gpgdir}/gnupg.nls/@var{langid}.mo}. Here @var{gpgdir} is the
3428 directory out of which the gpg binary has been loaded. If it can't be
3429 loaded the Registry is tried and as last resort the native Windows
3430 locale system is used.
3435 @c *******************************************
3436 @c *************** ****************
3437 @c *************** EXAMPLES ****************
3438 @c *************** ****************
3439 @c *******************************************
3446 @item gpg -se -r @code{Bob} @code{file}
3447 sign and encrypt for user Bob
3449 @item gpg --clearsign @code{file}
3450 make a clear text signature
3452 @item gpg -sb @code{file}
3453 make a detached signature
3455 @item gpg -u 0x12345678 -sb @code{file}
3456 make a detached signature with the key 0x12345678
3458 @item gpg --list-keys @code{user_ID}
3461 @item gpg --fingerprint @code{user_ID}
3464 @item gpg --verify @code{pgpfile}
3465 @itemx gpg --verify @code{sigfile} [@code{datafile}]
3466 Verify the signature of the file but do not output the data unless
3467 requested. The second form is used for detached signatures, where
3468 @code{sigfile} is the detached signature (either ASCII armored or
3469 binary) and @code{datafile} are the signed data; if this is not given, the name of the
3470 file holding the signed data is constructed by cutting off the
3471 extension (".asc" or ".sig") of @code{sigfile} or by asking the user
3472 for the filename. If the option @option{--output} is also used the
3473 signed data is written to the file specified by that option; use
3474 @code{-} to write the signed data to stdout.
3478 @c *******************************************
3479 @c *************** ****************
3480 @c *************** USER ID ****************
3481 @c *************** ****************
3482 @c *******************************************
3483 @mansect how to specify a user id
3485 @include specify-user-id.texi
3488 @mansect filter expressions
3489 @chapheading FILTER EXPRESSIONS
3491 The options @option{--import-filter} and @option{--export-filter} use
3492 expressions with this syntax (square brackets indicate an optional
3493 part and curly braces a repetition, white space between the elements
3498 [lc] @{[@{flag@}] PROPNAME op VALUE [lc]@}
3502 The name of a property (@var{PROPNAME}) may only consist of letters,
3503 digits and underscores. The description for the filter type
3504 describes which properties are defined. If an undefined property is
3505 used it evaluates to the empty string. Unless otherwise noted, the
3506 @var{VALUE} must always be given and may not be the empty string. No
3507 quoting is defined for the value, thus the value may not contain the
3508 strings @code{&&} or @code{||}, which are used as logical connection
3509 operators. The flag @code{--} can be used to remove this restriction.
3511 Numerical values are computed as long int; standard C notation
3512 applies. @var{lc} is the logical connection operator; either
3513 @code{&&} for a conjunction or @code{||} for a disjunction. A
3514 conjunction is assumed at the begin of an expression. Conjunctions
3515 have higher precedence than disjunctions. If @var{VALUE} starts with
3516 one of the characters used in any @var{op} a space after the
3517 @var{op} is required.
3520 The supported operators (@var{op}) are:
3525 Substring must match.
3528 Substring must not match.
3531 The full string must match.
3534 The full string must not match.
3537 The numerical value must match.
3540 The numerical value must not match.
3543 The numerical value of the field must be LE than the value.
3546 The numerical value of the field must be LT than the value.
3549 The numerical value of the field must be GT than the value.
3552 The numerical value of the field must be GE than the value.
3555 The string value of the field must be less or equal than the value.
3558 The string value of the field must be less than the value.
3561 The string value of the field must be greater than the value.
3564 The string value of the field must be greater or equal than the value.
3567 True if value is not empty (no value allowed).
3570 True if value is empty (no value allowed).
3573 Alias for "PROPNAME != 0" (no value allowed).
3576 Alias for "PROPNAME == 0" (no value allowed).
3581 Values for @var{flag} must be space separated. The supported flags
3586 @var{VALUE} spans to the end of the expression.
3588 The string match in this part is done case-sensitive.
3591 The filter options concatenate several specifications for a filter of
3592 the same type. For example the four options in this example:
3596 --import-option keep-uid="uid =~ Alfa"
3597 --import-option keep-uid="&& uid !~ Test"
3598 --import-option keep-uid="|| uid =~ Alpha"
3599 --import-option keep-uid="uid !~ Test"
3604 which is equivalent to
3609 keep-uid="uid =~ Alfa" && uid !~ Test" || uid =~ Alpha" && "uid !~ Test"
3613 imports only the user ids of a key containing the strings "Alfa"
3614 or "Alpha" but not the string "test".
3617 @mansect return value
3618 @chapheading RETURN VALUE
3620 The program returns 0 if everything was fine, 1 if at least
3621 a signature was bad, and other error codes for fatal errors.
3624 @chapheading WARNINGS
3626 Use a *good* password for your user account and a *good* passphrase
3627 to protect your secret key. This passphrase is the weakest part of the
3628 whole system. Programs to do dictionary attacks on your secret keyring
3629 are very easy to write and so you should protect your "~/.gnupg/"
3630 directory very well.
3632 Keep in mind that, if this program is used over a network (telnet), it
3633 is *very* easy to spy out your passphrase!
3635 If you are going to verify detached signatures, make sure that the
3636 program knows about it; either give both filenames on the command line
3637 or use @samp{-} to specify STDIN.
3639 @mansect interoperability
3640 @chapheading INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS
3642 GnuPG tries to be a very flexible implementation of the OpenPGP
3643 standard. In particular, GnuPG implements many of the optional parts
3644 of the standard, such as the SHA-512 hash, and the ZLIB and BZIP2
3645 compression algorithms. It is important to be aware that not all
3646 OpenPGP programs implement these optional algorithms and that by
3647 forcing their use via the @option{--cipher-algo},
3648 @option{--digest-algo}, @option{--cert-digest-algo}, or
3649 @option{--compress-algo} options in GnuPG, it is possible to create a
3650 perfectly valid OpenPGP message, but one that cannot be read by the
3653 There are dozens of variations of OpenPGP programs available, and each
3654 supports a slightly different subset of these optional algorithms.
3655 For example, until recently, no (unhacked) version of PGP supported
3656 the BLOWFISH cipher algorithm. A message using BLOWFISH simply could
3657 not be read by a PGP user. By default, GnuPG uses the standard
3658 OpenPGP preferences system that will always do the right thing and
3659 create messages that are usable by all recipients, regardless of which
3660 OpenPGP program they use. Only override this safe default if you
3661 really know what you are doing.
3663 If you absolutely must override the safe default, or if the preferences
3664 on a given key are invalid for some reason, you are far better off using
3665 the @option{--pgp6}, @option{--pgp7}, or @option{--pgp8} options. These
3666 options are safe as they do not force any particular algorithms in
3667 violation of OpenPGP, but rather reduce the available algorithms to a
3673 On older systems this program should be installed as setuid(root). This
3674 is necessary to lock memory pages. Locking memory pages prevents the
3675 operating system from writing memory pages (which may contain
3676 passphrases or other sensitive material) to disk. If you get no
3677 warning message about insecure memory your operating system supports
3678 locking without being root. The program drops root privileges as soon
3679 as locked memory is allocated.
3681 Note also that some systems (especially laptops) have the ability to
3682 ``suspend to disk'' (also known as ``safe sleep'' or ``hibernate'').
3683 This writes all memory to disk before going into a low power or even
3684 powered off mode. Unless measures are taken in the operating system
3685 to protect the saved memory, passphrases or other sensitive material
3686 may be recoverable from it later.
3688 Before you report a bug you should first search the mailing list
3689 archives for similar problems and second check whether such a bug has
3690 already been reported to our bug tracker at http://bugs.gnupg.org .
3692 @c *******************************************
3693 @c *************** **************
3694 @c *************** UNATTENDED **************
3695 @c *************** **************
3696 @c *******************************************
3698 @node Unattended Usage of GPG
3699 @section Unattended Usage
3701 @command{gpg} is often used as a backend engine by other software. To help
3702 with this a machine interface has been defined to have an unambiguous
3703 way to do this. The options @option{--status-fd} and @option{--batch}
3704 are almost always required for this.
3707 * Unattended GPG key generation:: Unattended key generation
3711 @node Unattended GPG key generation
3712 @subsection Unattended key generation
3714 The command @option{--gen-key} may be used along with the option
3715 @option{--batch} for unattended key generation. The parameters are
3716 either read from stdin or given as a file on the command line.
3717 The format of the parameter file is as follows:
3720 @item Text only, line length is limited to about 1000 characters.
3721 @item UTF-8 encoding must be used to specify non-ASCII characters.
3722 @item Empty lines are ignored.
3723 @item Leading and trailing while space is ignored.
3724 @item A hash sign as the first non white space character indicates
3726 @item Control statements are indicated by a leading percent sign, the
3727 arguments are separated by white space from the keyword.
3728 @item Parameters are specified by a keyword, followed by a colon. Arguments
3729 are separated by white space.
3731 The first parameter must be @samp{Key-Type}; control statements may be
3734 The order of the parameters does not matter except for @samp{Key-Type}
3735 which must be the first parameter. The parameters are only used for
3736 the generated keyblock (primary and subkeys); parameters from previous
3737 sets are not used. Some syntactically checks may be performed.
3739 Key generation takes place when either the end of the parameter file
3740 is reached, the next @samp{Key-Type} parameter is encountered or at the
3741 control statement @samp{%commit} is encountered.
3749 @item %echo @var{text}
3750 Print @var{text} as diagnostic.
3753 Suppress actual key generation (useful for syntax checking).
3756 Perform the key generation. Note that an implicit commit is done at
3757 the next @asis{Key-Type} parameter.
3759 @item %pubring @var{filename}
3760 @itemx %secring @var{filename}
3761 Do not write the key to the default or commandline given keyring but
3762 to @var{filename}. This must be given before the first commit to take
3763 place, duplicate specification of the same filename is ignored, the
3764 last filename before a commit is used. The filename is used until a
3765 new filename is used (at commit points) and all keys are written to
3766 that file. If a new filename is given, this file is created (and
3767 overwrites an existing one). For GnuPG versions prior to 2.1, both
3768 control statements must be given. For GnuPG 2.1 and later
3769 @samp{%secring} is a no-op.
3771 @item %ask-passphrase
3772 @itemx %no-ask-passphrase
3773 This option is a no-op for GnuPG 2.1 and later.
3775 @item %no-protection
3776 Using this option allows the creation of keys without any passphrase
3777 protection. This option is mainly intended for regression tests.
3779 @item %transient-key
3780 If given the keys are created using a faster and a somewhat less
3781 secure random number generator. This option may be used for keys
3782 which are only used for a short time and do not require full
3783 cryptographic strength. It takes only effect if used together with
3784 the control statement @samp{%no-protection}.
3793 @item Key-Type: @var{algo}
3794 Starts a new parameter block by giving the type of the primary
3795 key. The algorithm must be capable of signing. This is a required
3796 parameter. @var{algo} may either be an OpenPGP algorithm number or a
3797 string with the algorithm name. The special value @samp{default} may
3798 be used for @var{algo} to create the default key type; in this case a
3799 @samp{Key-Usage} shall not be given and @samp{default} also be used
3800 for @samp{Subkey-Type}.
3802 @item Key-Length: @var{nbits}
3803 The requested length of the generated key in bits. The default is
3804 returned by running the command @samp{@gpgname --gpgconf-list}.
3806 @item Key-Grip: @var{hexstring}
3807 This is optional and used to generate a CSR or certificate for an
3808 already existing key. Key-Length will be ignored when given.
3810 @item Key-Usage: @var{usage-list}
3811 Space or comma delimited list of key usages. Allowed values are
3812 @samp{encrypt}, @samp{sign}, and @samp{auth}. This is used to
3813 generate the key flags. Please make sure that the algorithm is
3814 capable of this usage. Note that OpenPGP requires that all primary
3815 keys are capable of certification, so no matter what usage is given
3816 here, the @samp{cert} flag will be on. If no @samp{Key-Usage} is
3817 specified and the @samp{Key-Type} is not @samp{default}, all allowed
3818 usages for that particular algorithm are used; if it is not given but
3819 @samp{default} is used the usage will be @samp{sign}.
3821 @item Subkey-Type: @var{algo}
3822 This generates a secondary key (subkey). Currently only one subkey
3823 can be handled. See also @samp{Key-Type} above.
3825 @item Subkey-Length: @var{nbits}
3826 Length of the secondary key (subkey) in bits. The default is returned
3827 by running the command @samp{@gpgname --gpgconf-list}.
3829 @item Subkey-Usage: @var{usage-list}
3830 Key usage lists for a subkey; similar to @samp{Key-Usage}.
3832 @item Passphrase: @var{string}
3833 If you want to specify a passphrase for the secret key, enter it here.
3834 Default is to use the Pinentry dialog to ask for a passphrase.
3836 @item Name-Real: @var{name}
3837 @itemx Name-Comment: @var{comment}
3838 @itemx Name-Email: @var{email}
3839 The three parts of a user name. Remember to use UTF-8 encoding here.
3840 If you don't give any of them, no user ID is created.
3842 @item Expire-Date: @var{iso-date}|(@var{number}[d|w|m|y])
3843 Set the expiration date for the key (and the subkey). It may either
3844 be entered in ISO date format (e.g. "20000815T145012") or as number of
3845 days, weeks, month or years after the creation date. The special
3846 notation "seconds=N" is also allowed to specify a number of seconds
3847 since creation. Without a letter days are assumed. Note that there
3848 is no check done on the overflow of the type used by OpenPGP for
3849 timestamps. Thus you better make sure that the given value make
3850 sense. Although OpenPGP works with time intervals, GnuPG uses an
3851 absolute value internally and thus the last year we can represent is
3854 @item Creation-Date: @var{iso-date}
3855 Set the creation date of the key as stored in the key information and
3856 which is also part of the fingerprint calculation. Either a date like
3857 "1986-04-26" or a full timestamp like "19860426T042640" may be used.
3858 The time is considered to be UTC. The special notation "seconds=N"
3859 may be used to directly specify a the number of seconds since Epoch
3860 (Unix time). If it is not given the current time is used.
3862 @item Preferences: @var{string}
3863 Set the cipher, hash, and compression preference values for this key.
3864 This expects the same type of string as the sub-command @samp{setpref}
3865 in the @option{--edit-key} menu.
3867 @item Revoker: @var{algo}:@var{fpr} [sensitive]
3868 Add a designated revoker to the generated key. Algo is the public key
3869 algorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.)
3870 @var{fpr} is the fingerprint of the designated revoker. The optional
3871 @samp{sensitive} flag marks the designated revoker as sensitive
3872 information. Only v4 keys may be designated revokers.
3874 @item Keyserver: @var{string}
3875 This is an optional parameter that specifies the preferred keyserver
3878 @item Handle: @var{string}
3879 This is an optional parameter only used with the status lines
3880 KEY_CREATED and KEY_NOT_CREATED. @var{string} may be up to 100
3881 characters and should not contain spaces. It is useful for batch key
3882 generation to associate a key parameter block with a status line.
3887 Here is an example on how to create a key:
3890 %echo Generating a basic OpenPGP key
3895 Name-Real: Joe Tester
3896 Name-Comment: with stupid passphrase
3897 Name-Email: joe@@foo.bar
3902 # Do a commit here, so that we can later print "done" :-)
3906 $ @gpgname --batch --gen-key foo
3908 $ @gpgname --no-default-keyring --secret-keyring ./foo.sec \
3909 --keyring ./foo.pub --list-secret-keys
3910 /home/wk/work/gnupg-stable/scratch/foo.sec
3911 ------------------------------------------
3912 sec 1024D/915A878D 2000-03-09 Joe Tester (with stupid passphrase) <joe@@foo.bar>
3913 ssb 1024g/8F70E2C0 2000-03-09
3918 If you want to create a key with the default algorithms you would use
3921 %echo Generating a default key
3923 Subkey-Type: default
3924 Name-Real: Joe Tester
3925 Name-Comment: with stupid passphrase
3926 Name-Email: joe@@foo.bar
3931 # Do a commit here, so that we can later print "done" :-)
3943 @command{gpg-agent}(1)
3945 @include see-also-note.texi