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 the bells and whistles you would expect from a full OpenPGP
67 There are two main versions of GnuPG: GnuPG 1.x and GnuPG 2.x. GnuPG
68 2.x supports modern encryption algorithms and thus should be preferred
69 over GnuPG 1.x. You only need to use GnuPG 1.x if your platform
70 doesn't support GnuPG 2.x, or you need support for some features that
71 GnuPG 2.x has deprecated, e.g., decrypting data created with PGP-2
75 If you are looking for version 1 of GnuPG, you may find that version
76 installed under the name @command{gpg1}.
79 In contrast to the standalone command @command{gpg} from GnuPG 1.x,
80 the 2.x version is commonly installed under the name
86 @xref{Option Index}, for an index to @command{@gpgname}'s commands and options.
90 * GPG Commands:: List of all commands.
91 * GPG Options:: List of all options.
92 * GPG Configuration:: Configuration files.
93 * GPG Examples:: Some usage examples.
95 Developer information:
96 * Unattended Usage of GPG:: Using @command{gpg} from other programs.
99 @c * GPG Protocol:: The protocol the server mode uses.
102 @c *******************************************
103 @c *************** ****************
104 @c *************** COMMANDS ****************
105 @c *************** ****************
106 @c *******************************************
111 Commands are not distinguished from options except for the fact that
112 only one command is allowed. Generally speaking, irrelevant options
113 are silently ignored, and may not be checked for correctness.
115 @command{@gpgname} may be run with no commands. In this case it will
116 perform a reasonable action depending on the type of file it is given
117 as input (an encrypted message is decrypted, a signature is verified,
118 a file containing keys is listed, etc.).
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 arbitrarily abbreviate this command
145 (though you can use its short form @option{-h}).
149 Print warranty information.
152 @opindex dump-options
153 Print a list of all available options and commands. Note that you cannot
154 abbreviate this command.
158 @c *******************************************
159 @c ******** OPERATIONAL COMMANDS ***********
160 @c *******************************************
161 @node Operational GPG Commands
162 @subsection Commands to select the type of operation
170 Sign a message. This command may be combined with @option{--encrypt}
171 (to sign and encrypt a message), @option{--symmetric} (to sign and
172 symmetrically encrypt a message), or both @option{--encrypt} and
173 @option{--symmetric} (to sign and encrypt a message that can be
174 decrypted using a secret key or a passphrase). The signing key is
175 chosen by default or can be set explicitly using the
176 @option{--local-user} and @option{--default-key} options.
182 Make a cleartext signature. The content in a cleartext signature is
183 readable without any special software. OpenPGP software is only needed
184 to verify the signature. cleartext signatures may modify end-of-line
185 whitespace for platform independence and are not intended to be
186 reversible. The signing key is chosen by default or can be set
187 explicitly using the @option{--local-user} and @option{--default-key}
194 Make a detached signature.
199 Encrypt data. This command may be combined with @option{--sign} (to
200 sign and encrypt a message), @option{--symmetric} (to encrypt a
201 message that can decrypted using a secret key or a passphrase), or
202 @option{--sign} and @option{--symmetric} together (for a signed
203 message that can be decrypted using a secret key or a passphrase).
208 Encrypt with a symmetric cipher using a passphrase. The default
209 symmetric cipher used is @value{GPGSYMENCALGO}, but may be chosen with the
210 @option{--cipher-algo} option. This command may be combined with
211 @option{--sign} (for a signed and symmetrically encrypted message),
212 @option{--encrypt} (for a message that may be decrypted via a secret key
213 or a passphrase), or @option{--sign} and @option{--encrypt} together
214 (for a signed message that may be decrypted via a secret key or a
219 Store only (make a simple literal data packet).
224 Decrypt the file given on the command line (or STDIN if no file
225 is specified) and write it to STDOUT (or the file specified with
226 @option{--output}). If the decrypted file is signed, the signature is also
227 verified. This command differs from the default operation, as it never
228 writes to the filename which is included in the file and it rejects
229 files that don't begin with an encrypted message.
233 Assume that the first argument is a signed file and verify it without
234 generating any output. With no arguments, the signature packet is
235 read from STDIN. If only one argument is given, the specified file is
236 expected to include a complete signature.
238 With more than one argument, the first argument should specify a file
239 with a detached signature and the remaining files should contain the
240 signed data. To read the signed data from STDIN, use @samp{-} as the
241 second filename. For security reasons, a detached signature will not
242 read the signed material from STDIN if not explicitly specified.
244 Note: If the option @option{--batch} is not used, @command{@gpgname}
245 may assume that a single argument is a file with a detached signature,
246 and it will try to find a matching data file by stripping certain
247 suffixes. Using this historical feature to verify a detached
248 signature is strongly discouraged; you should always specify the data file
251 Note: When verifying a cleartext signature, @command{@gpgname} verifies
252 only what makes up the cleartext signed data and not any extra data
253 outside of the cleartext signature or the header lines directly following
254 the dash marker line. The option @code{--output} may be used to write
255 out the actual signed data, but there are other pitfalls with this
256 format as well. It is suggested to avoid cleartext signatures in
257 favor of detached signatures.
259 Note: Sometimes the use of the @command{gpgv} tool is easier than
260 using the full-fledged @command{gpg} with this option. @command{gpgv}
261 is designed to compare signed data against a list of trusted keys and
262 returns with success only for a good signature. It has its own manual
268 This modifies certain other commands to accept multiple files for
269 processing on the command line or read from STDIN with each filename on
270 a separate line. This allows for many files to be processed at
271 once. @option{--multifile} may currently be used along with
272 @option{--verify}, @option{--encrypt}, and @option{--decrypt}. Note that
273 @option{--multifile --verify} may not be used with detached signatures.
276 @opindex verify-files
277 Identical to @option{--multifile --verify}.
279 @item --encrypt-files
280 @opindex encrypt-files
281 Identical to @option{--multifile --encrypt}.
283 @item --decrypt-files
284 @opindex decrypt-files
285 Identical to @option{--multifile --decrypt}.
289 @itemx --list-public-keys
291 List the specified keys. If no keys are specified, then all keys from
292 the configured public keyrings are listed.
294 Never use the output of this command in scripts or other programs.
295 The output is intended only for humans and its format is likely to
296 change. The @option{--with-colons} option emits the output in a
297 stable, machine-parseable format, which is intended for use by scripts
300 @item --list-secret-keys
302 @opindex list-secret-keys
303 List the specified secret keys. If no keys are specified, then all
304 known secret keys are listed. A @code{#} after the letters @code{sec}
305 means that the secret key is not usable (for example, if it was
306 exported using @option{--export-secret-subkeys}). See also
307 @option{--list-keys}.
309 @item --list-signatures
310 @opindex list-signatures
313 Same as @option{--list-keys}, but the signatures are listed too.
314 This command has the same effect as
315 using @option{--list-keys} with @option{--with-sig-list}.
317 For each signature listed, there are several flags in between the "sig"
318 tag and keyid. These flags give additional information about each
319 signature. From left to right, they are the numbers 1-3 for certificate
320 check level (see @option{--ask-cert-level}), "L" for a local or
321 non-exportable signature (see @option{--lsign-key}), "R" for a
322 nonRevocable signature (see the @option{--edit-key} command "nrsign"),
323 "P" for a signature that contains a policy URL (see
324 @option{--cert-policy-url}), "N" for a signature that contains a
325 notation (see @option{--cert-notation}), "X" for an eXpired signature
326 (see @option{--ask-cert-expire}), and the numbers 1-9 or "T" for 10 and
327 above to indicate trust signature levels (see the @option{--edit-key}
330 @item --check-signatures
331 @opindex check-signatures
334 Same as @option{--list-signatures}, but the signatures are verified. Note
335 that for performance reasons the revocation status of a signing key is
337 This command has the same effect as
338 using @option{--list-keys} with @option{--with-sig-check}.
340 The status of the verification is indicated by a flag directly following
341 the "sig" tag (and thus before the flags described above for
342 @option{--list-signatures}). A "!" indicates that the signature has been
343 successfully verified, a "-" denotes a bad signature and a "%" is used
344 if an error occurred while checking the signature (e.g. a non supported
349 Locate the keys given as arguments. This command basically uses the
350 same algorithm as used when locating keys for encryption or signing and
351 may thus be used to see what keys @command{@gpgname} might use. In
352 particular external methods as defined by @option{--auto-key-locate} may
353 be used to locate a key. Only public keys are listed.
357 List all keys (or the specified ones) along with their
358 fingerprints. This is the same output as @option{--list-keys} but with
359 the additional output of a line with the fingerprint. May also be
360 combined with @option{--list-signatures} or @option{--check-signatures}. If this
361 command is given twice, the fingerprints of all secondary keys are
362 listed too. This command also forces pretty printing of fingerprints
363 if the keyid format has been set to "none".
366 @opindex list-packets
367 List only the sequence of packets. This command is only useful for
368 debugging. When used with option @option{--verbose} the actual MPI
369 values are dumped and not only their lengths. Note that the output of
370 this command may change with new releases.
377 Present a menu to work with a smartcard. The subcommand "help" provides
378 an overview on available commands. For a detailed description, please
379 see the Card HOWTO at
380 https://gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .
384 Show the content of the smart card.
388 Present a menu to allow changing the PIN of a smartcard. This
389 functionality is also available as the subcommand "passwd" with the
390 @option{--edit-card} command.
392 @item --delete-keys @code{name}
393 @itemx --delete-keys @code{name}
394 Remove key from the public keyring. In batch mode either @option{--yes} is
395 required or the key must be specified by fingerprint. This is a
396 safeguard against accidental deletion of multiple keys.
398 @item --delete-secret-keys @code{name}
399 @opindex delete-secret-keys
400 Remove key from the secret keyring. In batch mode the key must be
401 specified by fingerprint. The option @option{--yes} can be used to
402 advice gpg-agent not to request a confirmation. This extra
403 pre-caution is done because @command{@gpgname} can't be sure that the
404 secret key (as controlled by gpg-agent) is only used for the given
408 @item --delete-secret-and-public-key @code{name}
409 @opindex delete-secret-and-public-key
410 Same as @option{--delete-key}, but if a secret key exists, it will be
411 removed first. In batch mode the key must be specified by fingerprint.
412 The option @option{--yes} can be used to advice gpg-agent not to
413 request a confirmation.
417 Either export all keys from all keyrings (default keyrings and those
418 registered via option @option{--keyring}), or if at least one name is given,
419 those of the given name. The exported keys are written to STDOUT or to the
420 file given with option @option{--output}. Use together with
421 @option{--armor} to mail those keys.
423 @item --send-keys @code{key IDs}
425 Similar to @option{--export} but sends the keys to a keyserver.
426 Fingerprints may be used instead of key IDs. Option @option{--keyserver}
427 must be used to give the name of this keyserver. Don't send your
428 complete keyring to a keyserver --- select only those keys which are new
429 or changed by you. If no key IDs are given, @command{@gpgname} does nothing.
431 @item --export-secret-keys
432 @itemx --export-secret-subkeys
433 @opindex export-secret-keys
434 @opindex export-secret-subkeys
435 Same as @option{--export}, but exports the secret keys instead. The
436 exported keys are written to STDOUT or to the file given with option
437 @option{--output}. This command is often used along with the option
438 @option{--armor} to allow for easy printing of the key for paper backup;
439 however the external tool @command{paperkey} does a better job of
440 creating backups on paper. Note that exporting a secret key can be a
441 security risk if the exported keys are sent over an insecure channel.
443 The second form of the command has the special property to render the
444 secret part of the primary key useless; this is a GNU extension to
445 OpenPGP and other implementations can not be expected to successfully
446 import such a key. Its intended use is in generating a full key with
447 an additional signing subkey on a dedicated machine. This command
448 then exports the key without the primary key to the main machine.
450 GnuPG may ask you to enter the passphrase for the key. This is
451 required, because the internal protection method of the secret key is
452 different from the one specified by the OpenPGP protocol.
454 @item --export-ssh-key
455 @opindex export-ssh-key
456 This command is used to export a key in the OpenSSH public key format.
457 It requires the specification of one key by the usual means and
458 exports the latest valid subkey which has an authentication capability
459 to STDOUT or to the file given with option @option{--output}. That
460 output can directly be added to ssh's @file{authorized_key} file.
462 By specifying the key to export using a key ID or a fingerprint
463 suffixed with an exclamation mark (!), a specific subkey or the
464 primary key can be exported. This does not even require that the key
465 has the authentication capability flag set.
470 Import/merge keys. This adds the given keys to the
471 keyring. The fast version is currently just a synonym.
473 There are a few other options which control how this command works.
474 Most notable here is the @option{--import-options merge-only} option
475 which does not insert new keys but does only the merging of new
476 signatures, user-IDs and subkeys.
478 @item --receive-keys @code{key IDs}
479 @opindex receive-keys
480 @itemx --recv-keys @code{key IDs}
482 Import the keys with the given key IDs from a keyserver. Option
483 @option{--keyserver} must be used to give the name of this keyserver.
486 @opindex refresh-keys
487 Request updates from a keyserver for keys that already exist on the
488 local keyring. This is useful for updating a key with the latest
489 signatures, user IDs, etc. Calling this with no arguments will refresh
490 the entire keyring. Option @option{--keyserver} must be used to give the
491 name of the keyserver for all keys that do not have preferred keyservers
492 set (see @option{--keyserver-options honor-keyserver-url}).
494 @item --search-keys @code{names}
496 Search the keyserver for the given names. Multiple names given here will
497 be joined together to create the search string for the keyserver.
498 Option @option{--keyserver} must be used to give the name of this
499 keyserver. Keyservers that support different search methods allow using
500 the syntax specified in "How to specify a user ID" below. Note that
501 different keyserver types support different search methods. Currently
502 only LDAP supports them all.
504 @item --fetch-keys @code{URIs}
506 Retrieve keys located at the specified URIs. Note that different
507 installations of GnuPG may support different protocols (HTTP, FTP,
508 LDAP, etc.). When using HTTPS the system provided root certificates
509 are used by this command.
511 @item --update-trustdb
512 @opindex update-trustdb
513 Do trust database maintenance. This command iterates over all keys and
514 builds the Web of Trust. This is an interactive command because it may
515 have to ask for the "ownertrust" values for keys. The user has to give
516 an estimation of how far she trusts the owner of the displayed key to
517 correctly certify (sign) other keys. GnuPG only asks for the ownertrust
518 value if it has not yet been assigned to a key. Using the
519 @option{--edit-key} menu, the assigned value can be changed at any time.
521 @item --check-trustdb
522 @opindex check-trustdb
523 Do trust database maintenance without user interaction. From time to
524 time the trust database must be updated so that expired keys or
525 signatures and the resulting changes in the Web of Trust can be
526 tracked. Normally, GnuPG will calculate when this is required and do it
527 automatically unless @option{--no-auto-check-trustdb} is set. This
528 command can be used to force a trust database check at any time. The
529 processing is identical to that of @option{--update-trustdb} but it
530 skips keys with a not yet defined "ownertrust".
532 For use with cron jobs, this command can be used together with
533 @option{--batch} in which case the trust database check is done only if
534 a check is needed. To force a run even in batch mode add the option
537 @anchor{option --export-ownertrust}
538 @item --export-ownertrust
539 @opindex export-ownertrust
540 Send the ownertrust values to STDOUT. This is useful for backup purposes
541 as these values are the only ones which can't be re-created from a
542 corrupted trustdb. Example:
545 @gpgname{} --export-ownertrust > otrust.txt
550 @item --import-ownertrust
551 @opindex import-ownertrust
552 Update the trustdb with the ownertrust values stored in @code{files} (or
553 STDIN if not given); existing values will be overwritten. In case of a
554 severely damaged trustdb and if you have a recent backup of the
555 ownertrust values (e.g. in the file @file{otrust.txt}), you may re-create
556 the trustdb using these commands:
561 @gpgname{} --import-ownertrust < otrust.txt
566 @item --rebuild-keydb-caches
567 @opindex rebuild-keydb-caches
568 When updating from version 1.0.6 to 1.0.7 this command should be used
569 to create signature caches in the keyring. It might be handy in other
572 @item --print-md @code{algo}
575 Print message digest of algorithm ALGO for all given files or STDIN.
576 With the second form (or a deprecated "*" as algo) digests for all
577 available algorithms are printed.
579 @item --gen-random @code{0|1|2} @code{count}
581 Emit @var{count} random bytes of the given quality level 0, 1 or 2. If
582 @var{count} is not given or zero, an endless sequence of random bytes
583 will be emitted. If used with @option{--armor} the output will be
584 base64 encoded. PLEASE, don't use this command unless you know what
585 you are doing; it may remove precious entropy from the system!
587 @item --gen-prime @code{mode} @code{bits}
589 Use the source, Luke :-). The output format is still subject to change.
596 Pack or unpack an arbitrary input into/from an OpenPGP ASCII armor.
597 This is a GnuPG extension to OpenPGP and in general not very useful.
599 @item --tofu-policy @code{auto|good|unknown|bad|ask} @code{key...}
601 Set the TOFU policy for all the bindings associated with the specified
602 keys. For more information about the meaning of the policies,
603 @pxref{trust-model-tofu}. The keys may be specified either by their
604 fingerprint (preferred) or their keyid.
608 @c Run gpg in server mode. This feature is not yet ready for use and
609 @c thus not documented.
614 @c *******************************************
615 @c ******* KEY MANGEMENT COMMANDS **********
616 @c *******************************************
617 @node OpenPGP Key Management
618 @subsection How to manage your keys
620 This section explains the main commands for key management.
624 @item --quick-generate-key @code{user-id} [@code{algo} [@code{usage} [@code{expire}]]]
625 @opindex quick-generate-key
626 This is a simple command to generate a standard key with one user id.
627 In contrast to @option{--generate-key} the key is generated directly
628 without the need to answer a bunch of prompts. Unless the option
629 @option{--yes} is given, the key creation will be canceled if the
630 given user id already exists in the keyring.
632 If invoked directly on the console without any special options an
633 answer to a ``Continue?'' style confirmation prompt is required. In
634 case the user id already exists in the keyring a second prompt to
635 force the creation of the key will show up.
637 If @code{algo} or @code{usage} are given, only the primary key is
638 created and no prompts are shown. To specify an expiration date but
639 still create a primary and subkey use ``default'' or
640 ``future-default'' for @code{algo} and ``default'' for @code{usage}.
641 For a description of these optional arguments see the command
642 @code{--quick-add-key}. The @code{usage} accepts also the value
643 ``cert'' which can be used to create a certification only primary key;
644 the default is to a create certification and signing key.
646 The @code{expire} argument can be used to specify an expiration date
647 for the key. Several formats are supported; commonly the ISO
648 YYYY-MM-DD format is used. The values ``never'', ``none'' can be used
649 for no expiration date. Not specifying a value, or using ``-''
650 results in a key expiring in a reasonable default interval.
652 If this command is used with @option{--batch},
653 @option{--pinentry-mode} has been set to @code{loopback}, and one of
654 the passphrase options (@option{--passphrase},
655 @option{--passphrase-fd}, or @option{passphrase-file}) is used, the
656 supplied passphrase is used for the new key and the agent does not ask
657 for it. To create a key without any protection @code{--passphrase ''}
660 @item --quick-set-expire @code{fpr} @code{expire}
661 @opindex quick-set-expire
662 Directly set the expiration time of the primary key to @code{expire}.
663 To remove the expiration time @code{0} can be used.
666 @item --quick-add-key @code{fpr} [@code{algo} [@code{usage} [@code{expire}]]]
667 @opindex quick-add-key
668 Directly add a subkey to the key identified by the fingerprint
669 @code{fpr}. Without the optional arguments an encryption subkey is
670 added. If any of the arguments are given a more specific subkey is
673 @code{algo} may be any of the supported algorithms or curve names
674 given in the format as used by key listings. To use the default
675 algorithm the string ``default'' or ``-'' can be used. Supported
676 algorithms are ``rsa'', ``dsa'', ``elg'', ``ed25519'', ``cv25519'',
677 and other ECC curves. For example the string ``rsa'' adds an RSA key
678 with the default key length; a string ``rsa4096'' requests that the
679 key length is 4096 bits. The string ``future-default'' is an alias
680 for the algorithm which will likely be used as default algorithm in
681 future versions of gpg.
683 Depending on the given @code{algo} the subkey may either be an
684 encryption subkey or a signing subkey. If an algorithm is capable of
685 signing and encryption and such a subkey is desired, a @code{usage}
686 string must be given. This string is either ``default'' or ``-'' to
687 keep the default or a comma delimited list of keywords: ``sign'' for a
688 signing subkey, ``auth'' for an authentication subkey, and ``encr''
689 for an encryption subkey (``encrypt'' can be used as alias for
690 ``encr''). The valid combinations depend on the algorithm.
692 The @code{expire} argument can be used to specify an expiration date
693 for the subkey. Several formats are supported; commonly the ISO
694 YYYY-MM-DD format is used. The values ``never'', ``none'', or ``-''
695 can be used for no expiration date.
698 @opindex generate-key
701 Generate a new key pair using the current default parameters. This is
702 the standard command to create a new key. In addition to the key a
703 revocation certificate is created and stored in the
704 @file{openpgp-revocs.d} directory below the GnuPG home directory.
706 @item --full-generate-key
707 @opindex full-generate-key
708 @itemx --full-gen-key
709 @opindex full-gen-key
710 Generate a new key pair with dialogs for all options. This is an
711 extended version of @option{--generate-key}.
713 There is also a feature which allows you to create keys in batch
714 mode. See the manual section ``Unattended key generation'' on how
718 @item --generate-revocation @code{name}
719 @opindex generate-revocation
720 @itemx --gen-revoke @code{name}
722 Generate a revocation certificate for the complete key. To only revoke
723 a subkey or a key signature, use the @option{--edit} command.
725 This command merely creates the revocation certificate so that it can
726 be used to revoke the key if that is ever needed. To actually revoke
727 a key the created revocation certificate needs to be merged with the
728 key to revoke. This is done by importing the revocation certificate
729 using the @option{--import} command. Then the revoked key needs to be
730 published, which is best done by sending the key to a keyserver
731 (command @option{--send-key}) and by exporting (@option{--export}) it
732 to a file which is then send to frequent communication partners.
735 @item --generate-designated-revocation @code{name}
736 @opindex generate-designated-revocation
737 @itemx --desig-revoke @code{name}
738 @opindex desig-revoke
739 Generate a designated revocation certificate for a key. This allows a
740 user (with the permission of the keyholder) to revoke someone else's
746 Present a menu which enables you to do most of the key management
747 related tasks. It expects the specification of a key on the command
750 @c ******** Begin Edit-key Options **********
755 Toggle selection of user ID or photographic user ID with index @code{n}.
756 Use @code{*} to select all and @code{0} to deselect all.
760 Toggle selection of subkey with index @code{n} or key ID @code{n}.
761 Use @code{*} to select all and @code{0} to deselect all.
764 @opindex keyedit:sign
765 Make a signature on key of user @code{name}. If the key is not yet
766 signed by the default user (or the users given with @option{-u}), the program
767 displays the information of the key again, together with its
768 fingerprint and asks whether it should be signed. This question is
769 repeated for all users specified with
773 @opindex keyedit:lsign
774 Same as "sign" but the signature is marked as non-exportable and will
775 therefore never be used by others. This may be used to make keys
776 valid only in the local environment.
779 @opindex keyedit:nrsign
780 Same as "sign" but the signature is marked as non-revocable and can
781 therefore never be revoked.
784 @opindex keyedit:tsign
785 Make a trust signature. This is a signature that combines the notions
786 of certification (like a regular signature), and trust (like the
787 "trust" command). It is generally only useful in distinct communities
788 or groups. For more information please read the sections
789 ``Trust Signature'' and ``Regular Expression'' in RFC-4880.
793 Note that "l" (for local / non-exportable), "nr" (for non-revocable,
794 and "t" (for trust) may be freely mixed and prefixed to "sign" to
795 create a signature of any type desired.
798 If the option @option{--only-sign-text-ids} is specified, then any
799 non-text based user ids (e.g., photo IDs) will not be selected for
805 @opindex keyedit:delsig
806 Delete a signature. Note that it is not possible to retract a signature,
807 once it has been send to the public (i.e. to a keyserver). In that case
808 you better use @code{revsig}.
811 @opindex keyedit:revsig
812 Revoke a signature. For every signature which has been generated by
813 one of the secret keys, GnuPG asks whether a revocation certificate
817 @opindex keyedit:check
818 Check the signatures on all selected user IDs. With the extra
819 option @code{selfsig} only self-signatures are shown.
822 @opindex keyedit:adduid
823 Create an additional user ID.
826 @opindex keyedit:addphoto
827 Create a photographic user ID. This will prompt for a JPEG file that
828 will be embedded into the user ID. Note that a very large JPEG will make
829 for a very large key. Also note that some programs will display your
830 JPEG unchanged (GnuPG), and some programs will scale it to fit in a
834 @opindex keyedit:showphoto
835 Display the selected photographic user ID.
838 @opindex keyedit:deluid
839 Delete a user ID or photographic user ID. Note that it is not
840 possible to retract a user id, once it has been send to the public
841 (i.e. to a keyserver). In that case you better use @code{revuid}.
844 @opindex keyedit:revuid
845 Revoke a user ID or photographic user ID.
848 @opindex keyedit:primary
849 Flag the current user id as the primary one, removes the primary user
850 id flag from all other user ids and sets the timestamp of all affected
851 self-signatures one second ahead. Note that setting a photo user ID
852 as primary makes it primary over other photo user IDs, and setting a
853 regular user ID as primary makes it primary over other regular user
857 @opindex keyedit:keyserver
858 Set a preferred keyserver for the specified user ID(s). This allows
859 other users to know where you prefer they get your key from. See
860 @option{--keyserver-options honor-keyserver-url} for more on how this
861 works. Setting a value of "none" removes an existing preferred
865 @opindex keyedit:notation
866 Set a name=value notation for the specified user ID(s). See
867 @option{--cert-notation} for more on how this works. Setting a value of
868 "none" removes all notations, setting a notation prefixed with a minus
869 sign (-) removes that notation, and setting a notation name (without the
870 =value) prefixed with a minus sign removes all notations with that name.
873 @opindex keyedit:pref
874 List preferences from the selected user ID. This shows the actual
875 preferences, without including any implied preferences.
878 @opindex keyedit:showpref
879 More verbose preferences listing for the selected user ID. This shows
880 the preferences in effect by including the implied preferences of 3DES
881 (cipher), SHA-1 (digest), and Uncompressed (compression) if they are
882 not already included in the preference list. In addition, the
883 preferred keyserver and signature notations (if any) are shown.
885 @item setpref @code{string}
886 @opindex keyedit:setpref
887 Set the list of user ID preferences to @code{string} for all (or just
888 the selected) user IDs. Calling setpref with no arguments sets the
889 preference list to the default (either built-in or set via
890 @option{--default-preference-list}), and calling setpref with "none"
891 as the argument sets an empty preference list. Use @command{@gpgname
892 --version} to get a list of available algorithms. Note that while you
893 can change the preferences on an attribute user ID (aka "photo ID"),
894 GnuPG does not select keys via attribute user IDs so these preferences
895 will not be used by GnuPG.
897 When setting preferences, you should list the algorithms in the order
898 which you'd like to see them used by someone else when encrypting a
899 message to your key. If you don't include 3DES, it will be
900 automatically added at the end. Note that there are many factors that
901 go into choosing an algorithm (for example, your key may not be the
902 only recipient), and so the remote OpenPGP application being used to
903 send to you may or may not follow your exact chosen order for a given
904 message. It will, however, only choose an algorithm that is present
905 on the preference list of every recipient key. See also the
906 INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below.
909 @opindex keyedit:addkey
910 Add a subkey to this key.
913 @opindex keyedit:addcardkey
914 Generate a subkey on a card and add it to this key.
917 @opindex keyedit:keytocard
918 Transfer the selected secret subkey (or the primary key if no subkey
919 has been selected) to a smartcard. The secret key in the keyring will
920 be replaced by a stub if the key could be stored successfully on the
921 card and you use the save command later. Only certain key types may be
922 transferred to the card. A sub menu allows you to select on what card
923 to store the key. Note that it is not possible to get that key back
924 from the card - if the card gets broken your secret key will be lost
925 unless you have a backup somewhere.
927 @item bkuptocard @code{file}
928 @opindex keyedit:bkuptocard
929 Restore the given file to a card. This command may be used to restore a
930 backup key (as generated during card initialization) to a new card. In
931 almost all cases this will be the encryption key. You should use this
932 command only with the corresponding public key and make sure that the
933 file given as argument is indeed the backup to restore. You should then
934 select 2 to restore as encryption key. You will first be asked to enter
935 the passphrase of the backup key and then for the Admin PIN of the card.
938 @opindex keyedit:delkey
939 Remove a subkey (secondary key). Note that it is not possible to retract
940 a subkey, once it has been send to the public (i.e. to a keyserver). In
941 that case you better use @code{revkey}. Also note that this only
942 deletes the public part of a key.
945 @opindex keyedit:revkey
949 @opindex keyedit:expire
950 Change the key or subkey expiration time. If a subkey is selected, the
951 expiration time of this subkey will be changed. With no selection, the
952 key expiration of the primary key is changed.
955 @opindex keyedit:trust
956 Change the owner trust value for the key. This updates the trust-db
957 immediately and no save is required.
961 @opindex keyedit:disable
962 @opindex keyedit:enable
963 Disable or enable an entire key. A disabled key can not normally be
967 @opindex keyedit:addrevoker
968 Add a designated revoker to the key. This takes one optional argument:
969 "sensitive". If a designated revoker is marked as sensitive, it will
970 not be exported by default (see export-options).
973 @opindex keyedit:passwd
974 Change the passphrase of the secret key.
977 @opindex keyedit:toggle
978 This is dummy command which exists only for backward compatibility.
981 @opindex keyedit:clean
982 Compact (by removing all signatures except the selfsig) any user ID
983 that is no longer usable (e.g. revoked, or expired). Then, remove any
984 signatures that are not usable by the trust calculations.
985 Specifically, this removes any signature that does not validate, any
986 signature that is superseded by a later signature, revoked signatures,
987 and signatures issued by keys that are not present on the keyring.
990 @opindex keyedit:minimize
991 Make the key as small as possible. This removes all signatures from
992 each user ID except for the most recent self-signature.
995 @opindex keyedit:cross-certify
996 Add cross-certification signatures to signing subkeys that may not
997 currently have them. Cross-certification signatures protect against a
998 subtle attack against signing subkeys. See
999 @option{--require-cross-certification}. All new keys generated have
1000 this signature by default, so this command is only useful to bring
1001 older keys up to date.
1004 @opindex keyedit:save
1005 Save all changes to the keyrings and quit.
1008 @opindex keyedit:quit
1009 Quit the program without updating the
1014 The listing shows you the key with its secondary keys and all user
1015 ids. The primary user id is indicated by a dot, and selected keys or
1016 user ids are indicated by an asterisk. The trust
1017 value is displayed with the primary key: the first is the assigned owner
1018 trust and the second is the calculated trust value. Letters are used for
1025 No ownertrust assigned / not yet calculated.
1029 calculation has failed; probably due to an expired key.
1032 Not enough information for calculation.
1035 Never trust this key.
1047 @c ******** End Edit-key Options **********
1049 @item --sign-key @code{name}
1051 Signs a public key with your secret key. This is a shortcut version of
1052 the subcommand "sign" from @option{--edit}.
1054 @item --lsign-key @code{name}
1056 Signs a public key with your secret key but marks it as
1057 non-exportable. This is a shortcut version of the subcommand "lsign"
1058 from @option{--edit-key}.
1060 @item --quick-sign-key @code{fpr} [@code{names}]
1061 @itemx --quick-lsign-key @code{fpr} [@code{names}]
1062 @opindex quick-sign-key
1063 @opindex quick-lsign-key
1064 Directly sign a key from the passphrase without any further user
1065 interaction. The @code{fpr} must be the verified primary fingerprint
1066 of a key in the local keyring. If no @code{names} are given, all
1067 useful user ids are signed; with given [@code{names}] only useful user
1068 ids matching one of theses names are signed. By default, or if a name
1069 is prefixed with a '*', a case insensitive substring match is used.
1070 If a name is prefixed with a '=' a case sensitive exact match is done.
1072 The command @option{--quick-lsign-key} marks the signatures as
1073 non-exportable. If such a non-exportable signature already exists the
1074 @option{--quick-sign-key} turns it into a exportable signature.
1076 This command uses reasonable defaults and thus does not provide the
1077 full flexibility of the "sign" subcommand from @option{--edit-key}.
1078 Its intended use is to help unattended key signing by utilizing a list
1079 of verified fingerprints.
1081 @item --quick-add-uid @var{user-id} @var{new-user-id}
1082 @opindex quick-add-uid
1083 This command adds a new user id to an existing key. In contrast to
1084 the interactive sub-command @code{adduid} of @option{--edit-key} the
1085 @var{new-user-id} is added verbatim with only leading and trailing
1086 white space removed, it is expected to be UTF-8 encoded, and no checks
1087 on its form are applied.
1089 @item --quick-revoke-uid @var{user-id} @var{user-id-to-revoke}
1090 @opindex quick-revoke-uid
1091 This command revokes a User ID on an existing key. It cannot be used
1092 to revoke the last User ID on key (some non-revoked User ID must
1093 remain), with revocation reason ``User ID is no longer valid''. If
1094 you want to specify a different revocation reason, or to supply
1095 supplementary revocation text, you should use the interactive
1096 sub-command @code{revuid} of @option{--edit-key}.
1098 @item --change-passphrase @var{user_id}
1099 @opindex change-passphrase
1100 @itemx --passwd @var{user_id}
1102 Change the passphrase of the secret key belonging to the certificate
1103 specified as @var{user_id}. This is a shortcut for the sub-command
1104 @code{passwd} of the edit key menu.
1109 @c *******************************************
1110 @c *************** ****************
1111 @c *************** OPTIONS ****************
1112 @c *************** ****************
1113 @c *******************************************
1116 @section Option Summary
1118 @command{@gpgname} features a bunch of options to control the exact
1119 behaviour and to change the default configuration.
1122 * GPG Configuration Options:: How to change the configuration.
1123 * GPG Key related Options:: Key related options.
1124 * GPG Input and Output:: Input and Output.
1125 * OpenPGP Options:: OpenPGP protocol specific options.
1126 * Compliance Options:: Compliance options.
1127 * GPG Esoteric Options:: Doing things one usually doesn't want to do.
1128 * Deprecated Options:: Deprecated options.
1131 Long options can be put in an options file (default
1132 "~/.gnupg/gpg.conf"). Short option names will not work - for example,
1133 "armor" is a valid option for the options file, while "a" is not. Do not
1134 write the 2 dashes, but simply the name of the option and any required
1135 arguments. Lines with a hash ('#') as the first non-white-space
1136 character are ignored. Commands may be put in this file too, but that is
1137 not generally useful as the command will execute automatically with
1138 every execution of gpg.
1140 Please remember that option parsing stops as soon as a non-option is
1141 encountered, you can explicitly stop parsing by using the special option
1144 @c *******************************************
1145 @c ******** CONFIGURATION OPTIONS **********
1146 @c *******************************************
1147 @node GPG Configuration Options
1148 @subsection How to change the configuration
1150 These options are used to change the configuration and are usually found
1155 @item --default-key @var{name}
1156 @opindex default-key
1157 Use @var{name} as the default key to sign with. If this option is not
1158 used, the default key is the first key found in the secret keyring.
1159 Note that @option{-u} or @option{--local-user} overrides this option.
1160 This option may be given multiple times. In this case, the last key
1161 for which a secret key is available is used. If there is no secret
1162 key available for any of the specified values, GnuPG will not emit an
1163 error message but continue as if this option wasn't given.
1165 @item --default-recipient @var{name}
1166 @opindex default-recipient
1167 Use @var{name} as default recipient if option @option{--recipient} is
1168 not used and don't ask if this is a valid one. @var{name} must be
1171 @item --default-recipient-self
1172 @opindex default-recipient-self
1173 Use the default key as default recipient if option @option{--recipient} is not
1174 used and don't ask if this is a valid one. The default key is the first
1175 one from the secret keyring or the one set with @option{--default-key}.
1177 @item --no-default-recipient
1178 @opindex no-default-recipient
1179 Reset @option{--default-recipient} and @option{--default-recipient-self}.
1183 Give more information during processing. If used
1184 twice, the input data is listed in detail.
1188 Reset verbose level to 0.
1192 Try to be as quiet as possible.
1198 Use batch mode. Never ask, do not allow interactive commands.
1199 @option{--no-batch} disables this option. Note that even with a
1200 filename given on the command line, gpg might still need to read from
1201 STDIN (in particular if gpg figures that the input is a
1202 detached signature and no data file has been specified). Thus if you
1203 do not want to feed data via STDIN, you should connect STDIN to
1206 It is highly recommended to use this option along with the options
1207 @option{--status-fd} and @option{--with-colons} for any unattended of
1212 Make sure that the TTY (terminal) is never used for any output.
1213 This option is needed in some cases because GnuPG sometimes prints
1214 warnings to the TTY even if @option{--batch} is used.
1218 Assume "yes" on most questions.
1222 Assume "no" on most questions.
1225 @item --list-options @code{parameters}
1226 @opindex list-options
1227 This is a space or comma delimited string that gives options used when
1228 listing keys and signatures (that is, @option{--list-keys},
1229 @option{--list-signatures}, @option{--list-public-keys},
1230 @option{--list-secret-keys}, and the @option{--edit-key} functions).
1231 Options can be prepended with a @option{no-} (after the two dashes) to
1232 give the opposite meaning. The options are:
1237 @opindex list-options:show-photos
1238 Causes @option{--list-keys}, @option{--list-signatures},
1239 @option{--list-public-keys}, and @option{--list-secret-keys} to
1240 display any photo IDs attached to the key. Defaults to no. See also
1241 @option{--photo-viewer}. Does not work with @option{--with-colons}:
1242 see @option{--attribute-fd} for the appropriate way to get photo data
1243 for scripts and other frontends.
1246 @opindex list-options:show-usage
1247 Show usage information for keys and subkeys in the standard key
1248 listing. This is a list of letters indicating the allowed usage for a
1249 key (@code{E}=encryption, @code{S}=signing, @code{C}=certification,
1250 @code{A}=authentication). Defaults to yes.
1252 @item show-policy-urls
1253 @opindex list-options:show-policy-urls
1254 Show policy URLs in the @option{--list-signatures} or @option{--check-signatures}
1255 listings. Defaults to no.
1257 @item show-notations
1258 @itemx show-std-notations
1259 @itemx show-user-notations
1260 @opindex list-options:show-notations
1261 @opindex list-options:show-std-notations
1262 @opindex list-options:show-user-notations
1263 Show all, IETF standard, or user-defined signature notations in the
1264 @option{--list-signatures} or @option{--check-signatures} listings. Defaults to no.
1266 @item show-keyserver-urls
1267 @opindex list-options:show-keyserver-urls
1268 Show any preferred keyserver URL in the @option{--list-signatures} or
1269 @option{--check-signatures} listings. Defaults to no.
1271 @item show-uid-validity
1272 @opindex list-options:show-uid-validity
1273 Display the calculated validity of user IDs during key listings.
1276 @item show-unusable-uids
1277 @opindex list-options:show-unusable-uids
1278 Show revoked and expired user IDs in key listings. Defaults to no.
1280 @item show-unusable-subkeys
1281 @opindex list-options:show-unusable-subkeys
1282 Show revoked and expired subkeys in key listings. Defaults to no.
1285 @opindex list-options:show-keyring
1286 Display the keyring name at the head of key listings to show which
1287 keyring a given key resides on. Defaults to no.
1289 @item show-sig-expire
1290 @opindex list-options:show-sig-expire
1291 Show signature expiration dates (if any) during @option{--list-signatures} or
1292 @option{--check-signatures} listings. Defaults to no.
1294 @item show-sig-subpackets
1295 @opindex list-options:show-sig-subpackets
1296 Include signature subpackets in the key listing. This option can take an
1297 optional argument list of the subpackets to list. If no argument is
1298 passed, list all subpackets. Defaults to no. This option is only
1299 meaningful when using @option{--with-colons} along with
1300 @option{--list-signatures} or @option{--check-signatures}.
1304 @item --verify-options @code{parameters}
1305 @opindex verify-options
1306 This is a space or comma delimited string that gives options used when
1307 verifying signatures. Options can be prepended with a `no-' to give
1308 the opposite meaning. The options are:
1313 @opindex verify-options:show-photos
1314 Display any photo IDs present on the key that issued the signature.
1315 Defaults to no. See also @option{--photo-viewer}.
1317 @item show-policy-urls
1318 @opindex verify-options:show-policy-urls
1319 Show policy URLs in the signature being verified. Defaults to yes.
1321 @item show-notations
1322 @itemx show-std-notations
1323 @itemx show-user-notations
1324 @opindex verify-options:show-notations
1325 @opindex verify-options:show-std-notations
1326 @opindex verify-options:show-user-notations
1327 Show all, IETF standard, or user-defined signature notations in the
1328 signature being verified. Defaults to IETF standard.
1330 @item show-keyserver-urls
1331 @opindex verify-options:show-keyserver-urls
1332 Show any preferred keyserver URL in the signature being verified.
1335 @item show-uid-validity
1336 @opindex verify-options:show-uid-validity
1337 Display the calculated validity of the user IDs on the key that issued
1338 the signature. Defaults to yes.
1340 @item show-unusable-uids
1341 @opindex verify-options:show-unusable-uids
1342 Show revoked and expired user IDs during signature verification.
1345 @item show-primary-uid-only
1346 @opindex verify-options:show-primary-uid-only
1347 Show only the primary user ID during signature verification. That is
1348 all the AKA lines as well as photo Ids are not shown with the signature
1349 verification status.
1352 @opindex verify-options:pka-lookups
1353 Enable PKA lookups to verify sender addresses. Note that PKA is based
1354 on DNS, and so enabling this option may disclose information on when
1355 and what signatures are verified or to whom data is encrypted. This
1356 is similar to the "web bug" described for the @option{--auto-key-retrieve}
1359 @item pka-trust-increase
1360 @opindex verify-options:pka-trust-increase
1361 Raise the trust in a signature to full if the signature passes PKA
1362 validation. This option is only meaningful if pka-lookups is set.
1365 @item --enable-large-rsa
1366 @itemx --disable-large-rsa
1367 @opindex enable-large-rsa
1368 @opindex disable-large-rsa
1369 With --generate-key and --batch, enable the creation of RSA secret keys as
1370 large as 8192 bit. Note: 8192 bit is more than is generally
1371 recommended. These large keys don't significantly improve security,
1372 but they are more expensive to use, and their signatures and
1373 certifications are larger. This option is only available if the
1374 binary was build with large-secmem support.
1377 @itemx --disable-dsa2
1378 @opindex enable-dsa2
1379 @opindex disable-dsa2
1380 Enable hash truncation for all DSA keys even for old DSA Keys up to
1381 1024 bit. This is also the default with @option{--openpgp}. Note
1382 that older versions of GnuPG also required this flag to allow the
1383 generation of DSA larger than 1024 bit.
1385 @item --photo-viewer @code{string}
1386 @opindex photo-viewer
1387 This is the command line that should be run to view a photo ID. "%i"
1388 will be expanded to a filename containing the photo. "%I" does the
1389 same, except the file will not be deleted once the viewer exits.
1390 Other flags are "%k" for the key ID, "%K" for the long key ID, "%f"
1391 for the key fingerprint, "%t" for the extension of the image type
1392 (e.g. "jpg"), "%T" for the MIME type of the image (e.g. "image/jpeg"),
1393 "%v" for the single-character calculated validity of the image being
1394 viewed (e.g. "f"), "%V" for the calculated validity as a string (e.g.
1395 "full"), "%U" for a base32 encoded hash of the user ID,
1396 and "%%" for an actual percent sign. If neither %i or %I are present,
1397 then the photo will be supplied to the viewer on standard input.
1399 The default viewer is "xloadimage -fork -quiet -title 'KeyID 0x%k'
1400 STDIN". Note that if your image viewer program is not secure, then
1401 executing it from GnuPG does not make it secure.
1403 @item --exec-path @code{string}
1406 Sets a list of directories to search for photo viewers and keyserver
1407 helpers. If not provided, keyserver helpers use the compiled-in
1408 default directory, and photo viewers use the @code{PATH} environment
1410 Note, that on W32 system this value is ignored when searching for
1413 @item --keyring @code{file}
1415 Add @code{file} to the current list of keyrings. If @code{file} begins
1416 with a tilde and a slash, these are replaced by the $HOME directory. If
1417 the filename does not contain a slash, it is assumed to be in the GnuPG
1418 home directory ("~/.gnupg" if @option{--homedir} or $GNUPGHOME is not
1421 Note that this adds a keyring to the current list. If the intent is to
1422 use the specified keyring alone, use @option{--keyring} along with
1423 @option{--no-default-keyring}.
1425 If the the option @option{--no-keyring} has been used no keyrings will
1429 @item --secret-keyring @code{file}
1430 @opindex secret-keyring
1431 This is an obsolete option and ignored. All secret keys are stored in
1432 the @file{private-keys-v1.d} directory below the GnuPG home directory.
1434 @item --primary-keyring @code{file}
1435 @opindex primary-keyring
1436 Designate @code{file} as the primary public keyring. This means that
1437 newly imported keys (via @option{--import} or keyserver
1438 @option{--recv-from}) will go to this keyring.
1440 @item --trustdb-name @code{file}
1441 @opindex trustdb-name
1442 Use @code{file} instead of the default trustdb. If @code{file} begins
1443 with a tilde and a slash, these are replaced by the $HOME directory. If
1444 the filename does not contain a slash, it is assumed to be in the GnuPG
1445 home directory (@file{~/.gnupg} if @option{--homedir} or $GNUPGHOME is
1448 @include opt-homedir.texi
1451 @item --display-charset @code{name}
1452 @opindex display-charset
1453 Set the name of the native character set. This is used to convert
1454 some informational strings like user IDs to the proper UTF-8 encoding.
1455 Note that this has nothing to do with the character set of data to be
1456 encrypted or signed; GnuPG does not recode user-supplied data. If
1457 this option is not used, the default character set is determined from
1458 the current locale. A verbosity level of 3 shows the chosen set.
1459 Valid values for @code{name} are:
1464 @opindex display-charset:iso-8859-1
1465 This is the Latin 1 set.
1468 @opindex display-charset:iso-8859-2
1472 @opindex display-charset:iso-8859-15
1473 This is currently an alias for
1477 @opindex display-charset:koi8-r
1478 The usual Russian set (RFC-1489).
1481 @opindex display-charset:utf-8
1482 Bypass all translations and assume
1483 that the OS uses native UTF-8 encoding.
1486 @item --utf8-strings
1487 @itemx --no-utf8-strings
1488 @opindex utf8-strings
1489 Assume that command line arguments are given as UTF-8 strings. The
1490 default (@option{--no-utf8-strings}) is to assume that arguments are
1491 encoded in the character set as specified by
1492 @option{--display-charset}. These options affect all following
1493 arguments. Both options may be used multiple times.
1495 @anchor{gpg-option --options}
1496 @item --options @code{file}
1498 Read options from @code{file} and do not try to read them from the
1499 default options file in the homedir (see @option{--homedir}). This
1500 option is ignored if used in an options file.
1504 Shortcut for @option{--options /dev/null}. This option is detected
1505 before an attempt to open an option file. Using this option will also
1506 prevent the creation of a @file{~/.gnupg} homedir.
1509 @itemx --compress-level @code{n}
1510 @itemx --bzip2-compress-level @code{n}
1511 @opindex compress-level
1512 @opindex bzip2-compress-level
1513 Set compression level to @code{n} for the ZIP and ZLIB compression
1514 algorithms. The default is to use the default compression level of zlib
1515 (normally 6). @option{--bzip2-compress-level} sets the compression level
1516 for the BZIP2 compression algorithm (defaulting to 6 as well). This is a
1517 different option from @option{--compress-level} since BZIP2 uses a
1518 significant amount of memory for each additional compression level.
1519 @option{-z} sets both. A value of 0 for @code{n} disables compression.
1521 @item --bzip2-decompress-lowmem
1522 @opindex bzip2-decompress-lowmem
1523 Use a different decompression method for BZIP2 compressed files. This
1524 alternate method uses a bit more than half the memory, but also runs
1525 at half the speed. This is useful under extreme low memory
1526 circumstances when the file was originally compressed at a high
1527 @option{--bzip2-compress-level}.
1530 @item --mangle-dos-filenames
1531 @itemx --no-mangle-dos-filenames
1532 @opindex mangle-dos-filenames
1533 @opindex no-mangle-dos-filenames
1534 Older version of Windows cannot handle filenames with more than one
1535 dot. @option{--mangle-dos-filenames} causes GnuPG to replace (rather
1536 than add to) the extension of an output filename to avoid this
1537 problem. This option is off by default and has no effect on non-Windows
1540 @item --ask-cert-level
1541 @itemx --no-ask-cert-level
1542 @opindex ask-cert-level
1543 When making a key signature, prompt for a certification level. If this
1544 option is not specified, the certification level used is set via
1545 @option{--default-cert-level}. See @option{--default-cert-level} for
1546 information on the specific levels and how they are
1547 used. @option{--no-ask-cert-level} disables this option. This option
1550 @item --default-cert-level @code{n}
1551 @opindex default-cert-level
1552 The default to use for the check level when signing a key.
1554 0 means you make no particular claim as to how carefully you verified
1557 1 means you believe the key is owned by the person who claims to own
1558 it but you could not, or did not verify the key at all. This is
1559 useful for a "persona" verification, where you sign the key of a
1562 2 means you did casual verification of the key. For example, this
1563 could mean that you verified the key fingerprint and checked the
1564 user ID on the key against a photo ID.
1566 3 means you did extensive verification of the key. For example, this
1567 could mean that you verified the key fingerprint with the owner of the
1568 key in person, and that you checked, by means of a hard to forge
1569 document with a photo ID (such as a passport) that the name of the key
1570 owner matches the name in the user ID on the key, and finally that you
1571 verified (by exchange of email) that the email address on the key
1572 belongs to the key owner.
1574 Note that the examples given above for levels 2 and 3 are just that:
1575 examples. In the end, it is up to you to decide just what "casual"
1576 and "extensive" mean to you.
1578 This option defaults to 0 (no particular claim).
1580 @item --min-cert-level
1581 @opindex min-cert-level
1582 When building the trust database, treat any signatures with a
1583 certification level below this as invalid. Defaults to 2, which
1584 disregards level 1 signatures. Note that level 0 "no particular
1585 claim" signatures are always accepted.
1587 @item --trusted-key @code{long key ID}
1588 @opindex trusted-key
1589 Assume that the specified key (which must be given
1590 as a full 8 byte key ID) is as trustworthy as one of
1591 your own secret keys. This option is useful if you
1592 don't want to keep your secret keys (or one of them)
1593 online but still want to be able to check the validity of a given
1594 recipient's or signator's key.
1596 @item --trust-model @code{pgp|classic|tofu|tofu+pgp|direct|always|auto}
1597 @opindex trust-model
1598 Set what trust model GnuPG should follow. The models are:
1603 @opindex trust-mode:pgp
1604 This is the Web of Trust combined with trust signatures as used in PGP
1605 5.x and later. This is the default trust model when creating a new
1609 @opindex trust-mode:classic
1610 This is the standard Web of Trust as introduced by PGP 2.
1613 @opindex trust-mode:tofu
1614 @anchor{trust-model-tofu}
1615 TOFU stands for Trust On First Use. In this trust model, the first
1616 time a key is seen, it is memorized. If later another key is seen
1617 with a user id with the same email address, a warning is displayed
1618 indicating that there is a conflict and that the key might be a
1619 forgery and an attempt at a man-in-the-middle attack.
1621 Because a potential attacker is able to control the email address
1622 and thereby circumvent the conflict detection algorithm by using an
1623 email address that is similar in appearance to a trusted email
1624 address, whenever a message is verified, statistics about the number
1625 of messages signed with the key are shown. In this way, a user can
1626 easily identify attacks using fake keys for regular correspondents.
1628 When compared with the Web of Trust, TOFU offers significantly
1629 weaker security guarantees. In particular, TOFU only helps ensure
1630 consistency (that is, that the binding between a key and email
1631 address doesn't change). A major advantage of TOFU is that it
1632 requires little maintenance to use correctly. To use the web of
1633 trust properly, you need to actively sign keys and mark users as
1634 trusted introducers. This is a time-consuming process and anecdotal
1635 evidence suggests that even security-conscious users rarely take the
1636 time to do this thoroughly and instead rely on an ad-hoc TOFU
1639 In the TOFU model, policies are associated with bindings between
1640 keys and email addresses (which are extracted from user ids and
1641 normalized). There are five policies, which can be set manually
1642 using the @option{--tofu-policy} option. The default policy can be
1643 set using the @option{--tofu-default-policy} option.
1645 The TOFU policies are: @code{auto}, @code{good}, @code{unknown},
1646 @code{bad} and @code{ask}. The @code{auto} policy is used by
1647 default (unless overridden by @option{--tofu-default-policy}) and
1648 marks a binding as marginally trusted. The @code{good},
1649 @code{unknown} and @code{bad} policies mark a binding as fully
1650 trusted, as having unknown trust or as having trust never,
1651 respectively. The @code{unknown} policy is useful for just using
1652 TOFU to detect conflicts, but to never assign positive trust to a
1653 binding. The final policy, @code{ask} prompts the user to indicate
1654 the binding's trust. If batch mode is enabled (or input is
1655 inappropriate in the context), then the user is not prompted and the
1656 @code{undefined} trust level is returned.
1659 @opindex trust-mode:tofu+pgp
1660 This trust model combines TOFU with the Web of Trust. This is done
1661 by computing the trust level for each model and then taking the
1662 maximum trust level where the trust levels are ordered as follows:
1663 @code{unknown < undefined < marginal < fully < ultimate < expired <
1666 By setting @option{--tofu-default-policy=unknown}, this model can be
1667 used to implement the web of trust with TOFU's conflict detection
1668 algorithm, but without its assignment of positive trust values,
1669 which some security-conscious users don't like.
1672 @opindex trust-mode:direct
1673 Key validity is set directly by the user and not calculated via the
1677 @opindex trust-mode:always
1678 Skip key validation and assume that used keys are always fully
1679 valid. You generally won't use this unless you are using some
1680 external validation scheme. This option also suppresses the
1681 "[uncertain]" tag printed with signature checks when there is no
1682 evidence that the user ID is bound to the key. Note that this
1683 trust model still does not allow the use of expired, revoked, or
1687 @opindex trust-mode:auto
1688 Select the trust model depending on whatever the internal trust
1689 database says. This is the default model if such a database already
1693 @item --auto-key-locate @code{parameters}
1694 @itemx --no-auto-key-locate
1695 @opindex auto-key-locate
1696 GnuPG can automatically locate and retrieve keys as needed using this
1697 option. This happens when encrypting to an email address (in the
1698 "user@@example.com" form), and there are no user@@example.com keys on
1699 the local keyring. This option takes any number of the following
1700 mechanisms, in the order they are to be tried:
1705 Locate a key using DNS CERT, as specified in RFC-4398.
1708 Locate a key using DNS PKA.
1711 Locate a key using DANE, as specified
1712 in draft-ietf-dane-openpgpkey-05.txt.
1715 Locate a key using the Web Key Directory protocol.
1716 This is an experimental method and semantics may change.
1719 Using DNS Service Discovery, check the domain in question for any LDAP
1720 keyservers to use. If this fails, attempt to locate the key using the
1721 PGP Universal method of checking @samp{ldap://keys.(thedomain)}.
1724 Locate a key using whatever keyserver is defined using the
1725 @option{--keyserver} option.
1728 In addition, a keyserver URL as used in the @option{--keyserver} option
1729 may be used here to query that particular keyserver.
1732 Locate the key using the local keyrings. This mechanism allows the user to
1733 select the order a local key lookup is done. Thus using
1734 @samp{--auto-key-locate local} is identical to
1735 @option{--no-auto-key-locate}.
1738 This flag disables the standard local key lookup, done before any of the
1739 mechanisms defined by the @option{--auto-key-locate} are tried. The
1740 position of this mechanism in the list does not matter. It is not
1741 required if @code{local} is also used.
1744 Clear all defined mechanisms. This is useful to override
1745 mechanisms given in a config file.
1749 @item --auto-key-retrieve
1750 @itemx --no-auto-key-retrieve
1751 @opindex auto-key-retrieve
1752 @opindex no-auto-key-retrieve
1753 This option enables the automatic retrieving of keys from a keyserver
1754 when verifying signatures made by keys that are not on the local
1757 If the method "wkd" is included in the list of methods given to
1758 @option{auto-key-locate}, the Signer's User ID is part of the
1759 signature, and the option @option{--disable-signer-uid} is not used,
1760 the "wkd" method may also be used to retrieve a key.
1762 Note that this option makes a "web bug" like behavior possible.
1763 Keyserver or Web Key Directory operators can see which keys you
1764 request, so by sending you a message signed by a brand new key (which
1765 you naturally will not have on your local keyring), the operator can
1766 tell both your IP address and the time when you verified the
1769 @item --keyid-format @code{none|short|0xshort|long|0xlong}
1770 @opindex keyid-format
1771 Select how to display key IDs. "none" does not show the key ID at all
1772 but shows the fingerprint in a separate line. "short" is the
1773 traditional 8-character key ID. "long" is the more accurate (but less
1774 convenient) 16-character key ID. Add an "0x" to either to include an
1775 "0x" at the beginning of the key ID, as in 0x99242560. Note that this
1776 option is ignored if the option @option{--with-colons} is used.
1778 @item --keyserver @code{name}
1780 This option is deprecated - please use the @option{--keyserver} in
1781 @file{dirmngr.conf} instead.
1783 Use @code{name} as your keyserver. This is the server that
1784 @option{--receive-keys}, @option{--send-keys}, and @option{--search-keys}
1785 will communicate with to receive keys from, send keys to, and search for
1786 keys on. The format of the @code{name} is a URI:
1787 `scheme:[//]keyservername[:port]' The scheme is the type of keyserver:
1788 "hkp" for the HTTP (or compatible) keyservers, "ldap" for the LDAP
1789 keyservers, or "mailto" for the Graff email keyserver. Note that your
1790 particular installation of GnuPG may have other keyserver types
1791 available as well. Keyserver schemes are case-insensitive. After the
1792 keyserver name, optional keyserver configuration options may be
1793 provided. These are the same as the global @option{--keyserver-options}
1794 from below, but apply only to this particular keyserver.
1796 Most keyservers synchronize with each other, so there is generally no
1797 need to send keys to more than one server. The keyserver
1798 @code{hkp://keys.gnupg.net} uses round robin DNS to give a different
1799 keyserver each time you use it.
1801 @item --keyserver-options @code{name=value}
1802 @opindex keyserver-options
1803 This is a space or comma delimited string that gives options for the
1804 keyserver. Options can be prefixed with a `no-' to give the opposite
1805 meaning. Valid import-options or export-options may be used here as
1806 well to apply to importing (@option{--recv-key}) or exporting
1807 (@option{--send-key}) a key from a keyserver. While not all options
1808 are available for all keyserver types, some common options are:
1812 @item include-revoked
1813 When searching for a key with @option{--search-keys}, include keys that
1814 are marked on the keyserver as revoked. Note that not all keyservers
1815 differentiate between revoked and unrevoked keys, and for such
1816 keyservers this option is meaningless. Note also that most keyservers do
1817 not have cryptographic verification of key revocations, and so turning
1818 this option off may result in skipping keys that are incorrectly marked
1821 @item include-disabled
1822 When searching for a key with @option{--search-keys}, include keys that
1823 are marked on the keyserver as disabled. Note that this option is not
1824 used with HKP keyservers.
1826 @item auto-key-retrieve
1827 This is an obsolete alias for the option @option{auto-key-retrieve}.
1828 Please do not use it; it will be removed in future versions..
1830 @item honor-keyserver-url
1831 When using @option{--refresh-keys}, if the key in question has a preferred
1832 keyserver URL, then use that preferred keyserver to refresh the key
1833 from. In addition, if auto-key-retrieve is set, and the signature
1834 being verified has a preferred keyserver URL, then use that preferred
1835 keyserver to fetch the key from. Note that this option introduces a
1836 "web bug": The creator of the key can see when the keys is
1837 refreshed. Thus this option is not enabled by default.
1839 @item honor-pka-record
1840 If @option{--auto-key-retrieve} is used, and the signature being
1841 verified has a PKA record, then use the PKA information to fetch
1842 the key. Defaults to "yes".
1844 @item include-subkeys
1845 When receiving a key, include subkeys as potential targets. Note that
1846 this option is not used with HKP keyservers, as they do not support
1847 retrieving keys by subkey id.
1850 Tell the keyserver helper program how long (in seconds) to try and
1851 perform a keyserver action before giving up. Note that performing
1852 multiple actions at the same time uses this timeout value per action.
1853 For example, when retrieving multiple keys via @option{--receive-keys}, the
1854 timeout applies separately to each key retrieval, and not to the
1855 @option{--receive-keys} command as a whole. Defaults to 30 seconds.
1857 @item http-proxy=@code{value}
1858 This option is deprecated.
1859 Set the proxy to use for HTTP and HKP keyservers.
1860 This overrides any proxy defined in @file{dirmngr.conf}.
1863 This option has no more function since GnuPG 2.1. Use the
1864 @code{dirmngr} configuration options instead.
1867 This option has no more function since GnuPG 2.1. Use the
1868 @code{dirmngr} configuration options instead.
1871 This option has no more function since GnuPG 2.1. Use the
1872 @code{dirmngr} configuration options instead.
1875 This option has no more function since GnuPG 2.1. Use the
1876 @code{dirmngr} configuration options instead.
1880 @item --completes-needed @code{n}
1881 @opindex compliant-needed
1882 Number of completely trusted users to introduce a new
1883 key signer (defaults to 1).
1885 @item --marginals-needed @code{n}
1886 @opindex marginals-needed
1887 Number of marginally trusted users to introduce a new
1888 key signer (defaults to 3)
1890 @item --tofu-default-policy @code{auto|good|unknown|bad|ask}
1891 @opindex tofu-default-policy
1892 The default TOFU policy (defaults to @code{auto}). For more
1893 information about the meaning of this option, @pxref{trust-model-tofu}.
1895 @item --max-cert-depth @code{n}
1896 @opindex max-cert-depth
1897 Maximum depth of a certification chain (default is 5).
1899 @item --no-sig-cache
1900 @opindex no-sig-cache
1901 Do not cache the verification status of key signatures.
1902 Caching gives a much better performance in key listings. However, if
1903 you suspect that your public keyring is not safe against write
1904 modifications, you can use this option to disable the caching. It
1905 probably does not make sense to disable it because all kind of damage
1906 can be done if someone else has write access to your public keyring.
1908 @item --auto-check-trustdb
1909 @itemx --no-auto-check-trustdb
1910 @opindex auto-check-trustdb
1911 If GnuPG feels that its information about the Web of Trust has to be
1912 updated, it automatically runs the @option{--check-trustdb} command
1913 internally. This may be a time consuming
1914 process. @option{--no-auto-check-trustdb} disables this option.
1917 @itemx --no-use-agent
1919 This is dummy option. @command{@gpgname} always requires the agent.
1921 @item --gpg-agent-info
1922 @opindex gpg-agent-info
1923 This is dummy option. It has no effect when used with @command{@gpgname}.
1926 @item --agent-program @var{file}
1927 @opindex agent-program
1928 Specify an agent program to be used for secret key operations. The
1929 default value is determined by running @command{gpgconf} with the
1930 option @option{--list-dirs}. Note that the pipe symbol (@code{|}) is
1931 used for a regression test suite hack and may thus not be used in the
1934 @item --dirmngr-program @var{file}
1935 @opindex dirmngr-program
1936 Specify a dirmngr program to be used for keyserver access. The
1937 default value is @file{@value{BINDIR}/dirmngr}.
1939 @item --no-autostart
1940 @opindex no-autostart
1941 Do not start the gpg-agent or the dirmngr if it has not yet been
1942 started and its service is required. This option is mostly useful on
1943 machines where the connection to gpg-agent has been redirected to
1944 another machines. If dirmngr is required on the remote machine, it
1945 may be started manually using @command{gpgconf --launch dirmngr}.
1949 Lock the databases the first time a lock is requested
1950 and do not release the lock until the process
1953 @item --lock-multiple
1954 @opindex lock-multiple
1955 Release the locks every time a lock is no longer
1956 needed. Use this to override a previous @option{--lock-once}
1961 Disable locking entirely. This option should be used only in very
1962 special environments, where it can be assured that only one process
1963 is accessing those files. A bootable floppy with a stand-alone
1964 encryption system will probably use this. Improper usage of this
1965 option may lead to data and key corruption.
1967 @item --exit-on-status-write-error
1968 @opindex exit-on-status-write-error
1969 This option will cause write errors on the status FD to immediately
1970 terminate the process. That should in fact be the default but it never
1971 worked this way and thus we need an option to enable this, so that the
1972 change won't break applications which close their end of a status fd
1973 connected pipe too early. Using this option along with
1974 @option{--enable-progress-filter} may be used to cleanly cancel long
1975 running gpg operations.
1977 @item --limit-card-insert-tries @code{n}
1978 @opindex limit-card-insert-tries
1979 With @code{n} greater than 0 the number of prompts asking to insert a
1980 smartcard gets limited to N-1. Thus with a value of 1 gpg won't at
1981 all ask to insert a card if none has been inserted at startup. This
1982 option is useful in the configuration file in case an application does
1983 not know about the smartcard support and waits ad infinitum for an
1986 @item --no-random-seed-file
1987 @opindex no-random-seed-file
1988 GnuPG uses a file to store its internal random pool over invocations.
1989 This makes random generation faster; however sometimes write operations
1990 are not desired. This option can be used to achieve that with the cost of
1991 slower random generation.
1994 @opindex no-greeting
1995 Suppress the initial copyright message.
1997 @item --no-secmem-warning
1998 @opindex no-secmem-warning
1999 Suppress the warning about "using insecure memory".
2001 @item --no-permission-warning
2002 @opindex permission-warning
2003 Suppress the warning about unsafe file and home directory (@option{--homedir})
2004 permissions. Note that the permission checks that GnuPG performs are
2005 not intended to be authoritative, but rather they simply warn about
2006 certain common permission problems. Do not assume that the lack of a
2007 warning means that your system is secure.
2009 Note that the warning for unsafe @option{--homedir} permissions cannot be
2010 suppressed in the gpg.conf file, as this would allow an attacker to
2011 place an unsafe gpg.conf file in place, and use this file to suppress
2012 warnings about itself. The @option{--homedir} permissions warning may only be
2013 suppressed on the command line.
2015 @item --no-mdc-warning
2016 @opindex no-mdc-warning
2017 Suppress the warning about missing MDC integrity protection.
2019 @item --require-secmem
2020 @itemx --no-require-secmem
2021 @opindex require-secmem
2022 Refuse to run if GnuPG cannot get secure memory. Defaults to no
2023 (i.e. run, but give a warning).
2026 @item --require-cross-certification
2027 @itemx --no-require-cross-certification
2028 @opindex require-cross-certification
2029 When verifying a signature made from a subkey, ensure that the cross
2030 certification "back signature" on the subkey is present and valid. This
2031 protects against a subtle attack against subkeys that can sign.
2032 Defaults to @option{--require-cross-certification} for
2038 Allow the user to do certain nonsensical or "silly" things like
2039 signing an expired or revoked key, or certain potentially incompatible
2040 things like generating unusual key types. This also disables certain
2041 warning messages about potentially incompatible actions. As the name
2042 implies, this option is for experts only. If you don't fully
2043 understand the implications of what it allows you to do, leave this
2044 off. @option{--no-expert} disables this option.
2049 @c *******************************************
2050 @c ******** KEY RELATED OPTIONS ************
2051 @c *******************************************
2052 @node GPG Key related Options
2053 @subsection Key related options
2057 @item --recipient @var{name}
2060 Encrypt for user id @var{name}. If this option or
2061 @option{--hidden-recipient} is not specified, GnuPG asks for the user-id
2062 unless @option{--default-recipient} is given.
2064 @item --hidden-recipient @var{name}
2066 @opindex hidden-recipient
2067 Encrypt for user ID @var{name}, but hide the key ID of this user's
2068 key. This option helps to hide the receiver of the message and is a
2069 limited countermeasure against traffic analysis. If this option or
2070 @option{--recipient} is not specified, GnuPG asks for the user ID unless
2071 @option{--default-recipient} is given.
2073 @item --recipient-file @var{file}
2075 @opindex recipient-file
2076 This option is similar to @option{--recipient} except that it
2077 encrypts to a key stored in the given file. @var{file} must be the
2078 name of a file containing exactly one key. @command{@gpgname} assumes that
2079 the key in this file is fully valid.
2081 @item --hidden-recipient-file @var{file}
2083 @opindex hidden-recipient-file
2084 This option is similar to @option{--hidden-recipient} except that it
2085 encrypts to a key stored in the given file. @var{file} must be the
2086 name of a file containing exactly one key. @command{@gpgname} assumes that
2087 the key in this file is fully valid.
2089 @item --encrypt-to @code{name}
2091 Same as @option{--recipient} but this one is intended for use in the
2092 options file and may be used with your own user-id as an
2093 "encrypt-to-self". These keys are only used when there are other
2094 recipients given either by use of @option{--recipient} or by the asked
2095 user id. No trust checking is performed for these user ids and even
2096 disabled keys can be used.
2098 @item --hidden-encrypt-to @code{name}
2099 @opindex hidden-encrypt-to
2100 Same as @option{--hidden-recipient} but this one is intended for use in the
2101 options file and may be used with your own user-id as a hidden
2102 "encrypt-to-self". These keys are only used when there are other
2103 recipients given either by use of @option{--recipient} or by the asked user id.
2104 No trust checking is performed for these user ids and even disabled
2107 @item --no-encrypt-to
2108 @opindex no-encrypt-to
2109 Disable the use of all @option{--encrypt-to} and
2110 @option{--hidden-encrypt-to} keys.
2112 @item --group @code{name=value}
2114 Sets up a named group, which is similar to aliases in email programs.
2115 Any time the group name is a recipient (@option{-r} or
2116 @option{--recipient}), it will be expanded to the values
2117 specified. Multiple groups with the same name are automatically merged
2118 into a single group.
2120 The values are @code{key IDs} or fingerprints, but any key description
2121 is accepted. Note that a value with spaces in it will be treated as
2122 two different values. Note also there is only one level of expansion
2123 --- you cannot make an group that points to another group. When used
2124 from the command line, it may be necessary to quote the argument to
2125 this option to prevent the shell from treating it as multiple
2128 @item --ungroup @code{name}
2130 Remove a given entry from the @option{--group} list.
2134 Remove all entries from the @option{--group} list.
2136 @item --local-user @var{name}
2139 Use @var{name} as the key to sign with. Note that this option overrides
2140 @option{--default-key}.
2142 @item --sender @var{mbox}
2144 This option has two purposes. @var{mbox} must either be a complete
2145 user id with a proper mail address or just a mail address. When
2146 creating a signature this option tells gpg the user id of a key used
2147 to make a signature if the key was not directly specified by a user
2148 id. When verifying a signature the @var{mbox} is used to restrict the
2149 information printed by the TOFU code to matching user ids.
2151 @item --try-secret-key @var{name}
2152 @opindex try-secret-key
2153 For hidden recipients GPG needs to know the keys to use for trial
2154 decryption. The key set with @option{--default-key} is always tried
2155 first, but this is often not sufficient. This option allows setting more
2156 keys to be used for trial decryption. Although any valid user-id
2157 specification may be used for @var{name} it makes sense to use at least
2158 the long keyid to avoid ambiguities. Note that gpg-agent might pop up a
2159 pinentry for a lot keys to do the trial decryption. If you want to stop
2160 all further trial decryption you may use close-window button instead of
2163 @item --try-all-secrets
2164 @opindex try-all-secrets
2165 Don't look at the key ID as stored in the message but try all secret
2166 keys in turn to find the right decryption key. This option forces the
2167 behaviour as used by anonymous recipients (created by using
2168 @option{--throw-keyids} or @option{--hidden-recipient}) and might come
2169 handy in case where an encrypted message contains a bogus key ID.
2171 @item --skip-hidden-recipients
2172 @itemx --no-skip-hidden-recipients
2173 @opindex skip-hidden-recipients
2174 @opindex no-skip-hidden-recipients
2175 During decryption skip all anonymous recipients. This option helps in
2176 the case that people use the hidden recipients feature to hide there
2177 own encrypt-to key from others. If oneself has many secret keys this
2178 may lead to a major annoyance because all keys are tried in turn to
2179 decrypt something which was not really intended for it. The drawback
2180 of this option is that it is currently not possible to decrypt a
2181 message which includes real anonymous recipients.
2186 @c *******************************************
2187 @c ******** INPUT AND OUTPUT ***************
2188 @c *******************************************
2189 @node GPG Input and Output
2190 @subsection Input and Output
2197 Create ASCII armored output. The default is to create the binary
2202 Assume the input data is not in ASCII armored format.
2204 @item --output @var{file}
2205 @itemx -o @var{file}
2207 Write output to @var{file}. To write to stdout use @code{-} as the
2210 @item --max-output @code{n}
2212 This option sets a limit on the number of bytes that will be generated
2213 when processing a file. Since OpenPGP supports various levels of
2214 compression, it is possible that the plaintext of a given message may be
2215 significantly larger than the original OpenPGP message. While GnuPG
2216 works properly with such messages, there is often a desire to set a
2217 maximum file size that will be generated before processing is forced to
2218 stop by the OS limits. Defaults to 0, which means "no limit".
2220 @item --input-size-hint @var{n}
2221 @opindex input-size-hint
2222 This option can be used to tell GPG the size of the input data in
2223 bytes. @var{n} must be a positive base-10 number. This option is
2224 only useful if the input is not taken from a file. GPG may use this
2225 hint to optimize its buffer allocation strategy. It is also used by
2226 the @option{--status-fd} line ``PROGRESS'' to provide a value for
2227 ``total'' if that is not available by other means.
2229 @item --import-options @code{parameters}
2230 @opindex import-options
2231 This is a space or comma delimited string that gives options for
2232 importing keys. Options can be prepended with a `no-' to give the
2233 opposite meaning. The options are:
2237 @item import-local-sigs
2238 Allow importing key signatures marked as "local". This is not
2239 generally useful unless a shared keyring scheme is being used.
2242 @item keep-ownertrust
2243 Normally possible still existing ownertrust values of a key are
2244 cleared if a key is imported. This is in general desirable so that
2245 a formerly deleted key does not automatically gain an ownertrust
2246 values merely due to import. On the other hand it is sometimes
2247 necessary to re-import a trusted set of keys again but keeping
2248 already assigned ownertrust values. This can be achieved by using
2251 @item repair-pks-subkey-bug
2252 During import, attempt to repair the damage caused by the PKS keyserver
2253 bug (pre version 0.9.6) that mangles keys with multiple subkeys. Note
2254 that this cannot completely repair the damaged key as some crucial data
2255 is removed by the keyserver, but it does at least give you back one
2256 subkey. Defaults to no for regular @option{--import} and to yes for
2257 keyserver @option{--receive-keys}.
2260 Show a listing of the key as imported right before it is stored.
2261 This can be combined with the option @option{--dry-run} to only look
2265 Run the entire import code but instead of storing the key to the
2266 local keyring write it to the output. The export options
2267 @option{export-pka} and @option{export-dane} affect the output. This
2268 option can be used to remove all invalid parts from a key without the
2272 During import, allow key updates to existing keys, but do not allow
2273 any new keys to be imported. Defaults to no.
2276 After import, compact (remove all signatures except the
2277 self-signature) any user IDs from the new key that are not usable.
2278 Then, remove any signatures from the new key that are not usable.
2279 This includes signatures that were issued by keys that are not present
2280 on the keyring. This option is the same as running the @option{--edit-key}
2281 command "clean" after import. Defaults to no.
2283 @item import-minimal
2284 Import the smallest key possible. This removes all signatures except
2285 the most recent self-signature on each user ID. This option is the
2286 same as running the @option{--edit-key} command "minimize" after import.
2290 @itemx import-restore
2291 Import in key restore mode. This imports all data which is usually
2292 skipped during import; including all GnuPG specific data. All other
2293 contradicting options are overridden.
2296 @item --import-filter @code{@var{name}=@var{expr}}
2297 @itemx --export-filter @code{@var{name}=@var{expr}}
2298 @opindex import-filter
2299 @opindex export-filter
2300 These options define an import/export filter which are applied to the
2301 imported/exported keyblock right before it will be stored/written.
2302 @var{name} defines the type of filter to use, @var{expr} the
2303 expression to evaluate. The option can be used several times which
2304 then appends more expression to the same @var{name}.
2307 The available filter types are:
2312 This filter will keep a user id packet and its dependent packets in
2313 the keyblock if the expression evaluates to true.
2316 This filter drops the selected subkeys.
2317 Currently only implemented for --export-filter.
2320 This filter drops the selected key signatures on user ids.
2321 Self-signatures are not considered.
2322 Currently only implemented for --import-filter.
2326 For the syntax of the expression see the chapter "FILTER EXPRESSIONS".
2327 The property names for the expressions depend on the actual filter
2328 type and are indicated in the following table.
2330 The available properties are:
2335 A string with the user id. (keep-uid)
2338 The addr-spec part of a user id with mailbox or the empty string.
2342 A number with the public key algorithm of a key or subkey packet.
2346 @itemx key_created_d
2347 The first is the timestamp a public key or subkey packet was
2348 created. The second is the same but given as an ISO string,
2349 e.g. "2016-08-17". (drop-subkey)
2352 Boolean indicating whether the user id is the primary one. (keep-uid)
2355 Boolean indicating whether a key or subkey is a secret one.
2359 @itemx sig_created_d
2360 The first is the timestamp a signature packet was created. The
2361 second is the same but given as an ISO string,
2362 e.g. "2016-08-17". (drop-sig)
2365 A number with the public key algorithm of a signature packet. (drop-sig)
2367 @item sig_digest_algo
2368 A number with the digest algorithm of a signature packet. (drop-sig)
2372 @item --export-options @code{parameters}
2373 @opindex export-options
2374 This is a space or comma delimited string that gives options for
2375 exporting keys. Options can be prepended with a `no-' to give the
2376 opposite meaning. The options are:
2380 @item export-local-sigs
2381 Allow exporting key signatures marked as "local". This is not
2382 generally useful unless a shared keyring scheme is being used.
2385 @item export-attributes
2386 Include attribute user IDs (photo IDs) while exporting. This is
2387 useful to export keys if they are going to be used by an OpenPGP
2388 program that does not accept attribute user IDs. Defaults to yes.
2390 @item export-sensitive-revkeys
2391 Include designated revoker information that was marked as
2392 "sensitive". Defaults to no.
2394 @c Since GnuPG 2.1 gpg-agent manages the secret key and thus the
2395 @c export-reset-subkey-passwd hack is not anymore justified. Such use
2396 @c cases may be implemented using a specialized secret key export
2398 @c @item export-reset-subkey-passwd
2399 @c When using the @option{--export-secret-subkeys} command, this option resets
2400 @c the passphrases for all exported subkeys to empty. This is useful
2401 @c when the exported subkey is to be used on an unattended machine where
2402 @c a passphrase doesn't necessarily make sense. Defaults to no.
2405 @itemx export-backup
2406 Export for use as a backup. The exported data includes all data
2407 which is needed to restore the key or keys later with GnuPG. The
2408 format is basically the OpenPGP format but enhanced with GnuPG
2409 specific data. All other contradicting options are overridden.
2412 Compact (remove all signatures from) user IDs on the key being
2413 exported if the user IDs are not usable. Also, do not export any
2414 signatures that are not usable. This includes signatures that were
2415 issued by keys that are not present on the keyring. This option is
2416 the same as running the @option{--edit-key} command "clean" before export
2417 except that the local copy of the key is not modified. Defaults to
2420 @item export-minimal
2421 Export the smallest key possible. This removes all signatures except the
2422 most recent self-signature on each user ID. This option is the same as
2423 running the @option{--edit-key} command "minimize" before export except
2424 that the local copy of the key is not modified. Defaults to no.
2427 Instead of outputting the key material output PKA records suitable
2428 to put into DNS zone files. An ORIGIN line is printed before each
2429 record to allow diverting the records to the corresponding zone file.
2432 Instead of outputting the key material output OpenPGP DANE records
2433 suitable to put into DNS zone files. An ORIGIN line is printed before
2434 each record to allow diverting the records to the corresponding zone
2440 @opindex with-colons
2441 Print key listings delimited by colons. Note that the output will be
2442 encoded in UTF-8 regardless of any @option{--display-charset} setting. This
2443 format is useful when GnuPG is called from scripts and other programs
2444 as it is easily machine parsed. The details of this format are
2445 documented in the file @file{doc/DETAILS}, which is included in the GnuPG
2446 source distribution.
2448 @item --fixed-list-mode
2449 @opindex fixed-list-mode
2450 Do not merge primary user ID and primary key in @option{--with-colon}
2451 listing mode and print all timestamps as seconds since 1970-01-01.
2452 Since GnuPG 2.0.10, this mode is always used and thus this option is
2453 obsolete; it does not harm to use it though.
2455 @item --legacy-list-mode
2456 @opindex legacy-list-mode
2457 Revert to the pre-2.1 public key list mode. This only affects the
2458 human readable output and not the machine interface
2459 (i.e. @code{--with-colons}). Note that the legacy format does not
2460 convey suitable information for elliptic curves.
2462 @item --with-fingerprint
2463 @opindex with-fingerprint
2464 Same as the command @option{--fingerprint} but changes only the format
2465 of the output and may be used together with another command.
2467 @item --with-subkey-fingerprint
2468 @opindex with-subkey-fingerprint
2469 If a fingerprint is printed for the primary key, this option forces
2470 printing of the fingerprint for all subkeys. This could also be
2471 achieved by using the @option{--with-fingerprint} twice but by using
2472 this option along with keyid-format "none" a compact fingerprint is
2475 @item --with-icao-spelling
2476 @opindex with-icao-spelling
2477 Print the ICAO spelling of the fingerprint in addition to the hex digits.
2479 @item --with-keygrip
2480 @opindex with-keygrip
2481 Include the keygrip in the key listings. In @code{--with-colons} mode
2482 this is implicitly enable for secret keys.
2484 @item --with-wkd-hash
2485 @opindex with-wkd-hash
2486 Print a Web Key Directory identifier along with each user ID in key
2487 listings. This is an experimental feature and semantics may change.
2490 @opindex with-secret
2491 Include info about the presence of a secret key in public key listings
2492 done with @code{--with-colons}.
2496 @c *******************************************
2497 @c ******** OPENPGP OPTIONS ****************
2498 @c *******************************************
2499 @node OpenPGP Options
2500 @subsection OpenPGP protocol specific options
2504 @item -t, --textmode
2505 @itemx --no-textmode
2507 Treat input files as text and store them in the OpenPGP canonical text
2508 form with standard "CRLF" line endings. This also sets the necessary
2509 flags to inform the recipient that the encrypted or signed data is text
2510 and may need its line endings converted back to whatever the local
2511 system uses. This option is useful when communicating between two
2512 platforms that have different line ending conventions (UNIX-like to Mac,
2513 Mac to Windows, etc). @option{--no-textmode} disables this option, and
2516 @item --force-v3-sigs
2517 @itemx --no-force-v3-sigs
2518 @item --force-v4-certs
2519 @itemx --no-force-v4-certs
2520 These options are obsolete and have no effect since GnuPG 2.1.
2524 Force the use of encryption with a modification detection code. This
2525 is always used with the newer ciphers (those with a blocksize greater
2526 than 64 bits), or if all of the recipient keys indicate MDC support in
2527 their feature flags.
2530 @opindex disable-mdc
2531 Disable the use of the modification detection code. Note that by
2532 using this option, the encrypted message becomes vulnerable to a
2533 message modification attack.
2535 @item --disable-signer-uid
2536 @opindex disable-signer-uid
2537 By default the user ID of the signing key is embedded in the data
2538 signature. As of now this is only done if the signing key has been
2539 specified with @option{local-user} using a mail address. This
2540 information can be helpful for verifier to locate the key; see
2541 option @option{--auto-key-retrieve}.
2543 @item --personal-cipher-preferences @code{string}
2544 @opindex personal-cipher-preferences
2545 Set the list of personal cipher preferences to @code{string}. Use
2546 @command{@gpgname --version} to get a list of available algorithms,
2547 and use @code{none} to set no preference at all. This allows the user
2548 to safely override the algorithm chosen by the recipient key
2549 preferences, as GPG will only select an algorithm that is usable by
2550 all recipients. The most highly ranked cipher in this list is also
2551 used for the @option{--symmetric} encryption command.
2553 @item --personal-digest-preferences @code{string}
2554 @opindex personal-digest-preferences
2555 Set the list of personal digest preferences to @code{string}. Use
2556 @command{@gpgname --version} to get a list of available algorithms,
2557 and use @code{none} to set no preference at all. This allows the user
2558 to safely override the algorithm chosen by the recipient key
2559 preferences, as GPG will only select an algorithm that is usable by
2560 all recipients. The most highly ranked digest algorithm in this list
2561 is also used when signing without encryption
2562 (e.g. @option{--clear-sign} or @option{--sign}).
2564 @item --personal-compress-preferences @code{string}
2565 @opindex personal-compress-preferences
2566 Set the list of personal compression preferences to @code{string}.
2567 Use @command{@gpgname --version} to get a list of available
2568 algorithms, and use @code{none} to set no preference at all. This
2569 allows the user to safely override the algorithm chosen by the
2570 recipient key preferences, as GPG will only select an algorithm that
2571 is usable by all recipients. The most highly ranked compression
2572 algorithm in this list is also used when there are no recipient keys
2573 to consider (e.g. @option{--symmetric}).
2575 @item --s2k-cipher-algo @code{name}
2576 @opindex s2k-cipher-algo
2577 Use @code{name} as the cipher algorithm for symmetric encryption with
2578 a passphrase if @option{--personal-cipher-preferences} and
2579 @option{--cipher-algo} are not given. The default is @value{GPGSYMENCALGO}.
2581 @item --s2k-digest-algo @code{name}
2582 @opindex s2k-digest-algo
2583 Use @code{name} as the digest algorithm used to mangle the passphrases
2584 for symmetric encryption. The default is SHA-1.
2586 @item --s2k-mode @code{n}
2588 Selects how passphrases for symmetric encryption are mangled. If
2589 @code{n} is 0 a plain passphrase (which is in general not recommended)
2590 will be used, a 1 adds a salt (which should not be used) to the
2591 passphrase and a 3 (the default) iterates the whole process a number
2592 of times (see @option{--s2k-count}).
2594 @item --s2k-count @code{n}
2596 Specify how many times the passphrases mangling for symmetric
2597 encryption is repeated. This value may range between 1024 and
2598 65011712 inclusive. The default is inquired from gpg-agent. Note
2599 that not all values in the 1024-65011712 range are legal and if an
2600 illegal value is selected, GnuPG will round up to the nearest legal
2601 value. This option is only meaningful if @option{--s2k-mode} is set
2602 to the default of 3.
2607 @c ***************************
2608 @c ******* Compliance ********
2609 @c ***************************
2610 @node Compliance Options
2611 @subsection Compliance options
2613 These options control what GnuPG is compliant to. Only one of these
2614 options may be active at a time. Note that the default setting of
2615 this is nearly always the correct one. See the INTEROPERABILITY WITH
2616 OTHER OPENPGP PROGRAMS section below before using one of these
2623 Use standard GnuPG behavior. This is essentially OpenPGP behavior
2624 (see @option{--openpgp}), but with some additional workarounds for common
2625 compatibility problems in different versions of PGP. This is the
2626 default option, so it is not generally needed, but it may be useful to
2627 override a different compliance option in the gpg.conf file.
2631 Reset all packet, cipher and digest options to strict OpenPGP
2632 behavior. Use this option to reset all previous options like
2633 @option{--s2k-*}, @option{--cipher-algo}, @option{--digest-algo} and
2634 @option{--compress-algo} to OpenPGP compliant values. All PGP
2635 workarounds are disabled.
2639 Reset all packet, cipher and digest options to strict RFC-4880
2640 behavior. Note that this is currently the same thing as
2645 Enable experimental features from proposed updates to RFC-4880. This
2646 option can be used in addition to the other compliance options.
2647 Warning: The behavior may change with any GnuPG release and created
2648 keys or data may not be usable with future GnuPG versions.
2652 Reset all packet, cipher and digest options to strict RFC-2440
2657 Set up all options to be as PGP 6 compliant as possible. This
2658 restricts you to the ciphers IDEA (if the IDEA plugin is installed),
2659 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160, and the
2660 compression algorithms none and ZIP. This also disables
2661 @option{--throw-keyids}, and making signatures with signing subkeys as PGP 6
2662 does not understand signatures made by signing subkeys.
2664 This option implies @option{--disable-mdc --escape-from-lines}.
2668 Set up all options to be as PGP 7 compliant as possible. This is
2669 identical to @option{--pgp6} except that MDCs are not disabled, and the
2670 list of allowable ciphers is expanded to add AES128, AES192, AES256, and
2675 Set up all options to be as PGP 8 compliant as possible. PGP 8 is a lot
2676 closer to the OpenPGP standard than previous versions of PGP, so all
2677 this does is disable @option{--throw-keyids} and set
2678 @option{--escape-from-lines}. All algorithms are allowed except for the
2679 SHA224, SHA384, and SHA512 digests.
2681 @item --compliance @var{string}
2683 This option can be used instead of one of the options above. Valid
2684 values for @var{string} are the above option names (without the double
2685 dash) and possibly others as shown when using "help" for @var{value}.
2690 @c *******************************************
2691 @c ******** ESOTERIC OPTIONS ***************
2692 @c *******************************************
2693 @node GPG Esoteric Options
2694 @subsection Doing things one usually doesn't want to do
2701 Don't make any changes (this is not completely implemented).
2705 Changes the behaviour of some commands. This is like @option{--dry-run} but
2706 different in some cases. The semantic of this option may be extended in
2707 the future. Currently it only skips the actual decryption pass and
2708 therefore enables a fast listing of the encryption keys.
2711 @itemx --interactive
2712 @opindex interactive
2713 Prompt before overwriting any files.
2715 @item --debug-level @var{level}
2716 @opindex debug-level
2717 Select the debug level for investigating problems. @var{level} may be
2718 a numeric value or by a keyword:
2722 No debugging at all. A value of less than 1 may be used instead of
2725 Some basic debug messages. A value between 1 and 2 may be used
2726 instead of the keyword.
2728 More verbose debug messages. A value between 3 and 5 may be used
2729 instead of the keyword.
2731 Even more detailed messages. A value between 6 and 8 may be used
2732 instead of the keyword.
2734 All of the debug messages you can get. A value greater than 8 may be
2735 used instead of the keyword. The creation of hash tracing files is
2736 only enabled if the keyword is used.
2739 How these messages are mapped to the actual debugging flags is not
2740 specified and may change with newer releases of this program. They are
2741 however carefully selected to best aid in debugging.
2743 @item --debug @var{flags}
2745 Set debugging flags. All flags are or-ed and @var{flags} may be given
2746 in C syntax (e.g. 0x0042) or as a comma separated list of flag names.
2747 To get a list of all supported flags the single word "help" can be
2752 Set all useful debugging flags.
2755 @opindex debug-iolbf
2756 Set stdout into line buffered mode. This option is only honored when
2757 given on the command line.
2759 @item --faked-system-time @var{epoch}
2760 @opindex faked-system-time
2761 This option is only useful for testing; it sets the system time back or
2762 forth to @var{epoch} which is the number of seconds elapsed since the year
2763 1970. Alternatively @var{epoch} may be given as a full ISO time string
2764 (e.g. "20070924T154812").
2766 If you suffix @var{epoch} with an exclamation mark (!), the system time
2767 will appear to be frozen at the specified time.
2769 @item --enable-progress-filter
2770 @opindex enable-progress-filter
2771 Enable certain PROGRESS status outputs. This option allows frontends
2772 to display a progress indicator while gpg is processing larger files.
2773 There is a slight performance overhead using it.
2775 @item --status-fd @code{n}
2777 Write special status strings to the file descriptor @code{n}.
2778 See the file DETAILS in the documentation for a listing of them.
2780 @item --status-file @code{file}
2781 @opindex status-file
2782 Same as @option{--status-fd}, except the status data is written to file
2785 @item --logger-fd @code{n}
2787 Write log output to file descriptor @code{n} and not to STDERR.
2789 @item --log-file @code{file}
2790 @itemx --logger-file @code{file}
2792 Same as @option{--logger-fd}, except the logger data is written to
2793 file @code{file}. Use @file{socket://} to log to socket.
2795 @item --attribute-fd @code{n}
2796 @opindex attribute-fd
2797 Write attribute subpackets to the file descriptor @code{n}. This is most
2798 useful for use with @option{--status-fd}, since the status messages are
2799 needed to separate out the various subpackets from the stream delivered
2800 to the file descriptor.
2802 @item --attribute-file @code{file}
2803 @opindex attribute-file
2804 Same as @option{--attribute-fd}, except the attribute data is written to
2807 @item --comment @code{string}
2808 @itemx --no-comments
2810 Use @code{string} as a comment string in cleartext signatures and ASCII
2811 armored messages or keys (see @option{--armor}). The default behavior is
2812 not to use a comment string. @option{--comment} may be repeated multiple
2813 times to get multiple comment strings. @option{--no-comments} removes
2814 all comments. It is a good idea to keep the length of a single comment
2815 below 60 characters to avoid problems with mail programs wrapping such
2816 lines. Note that comment lines, like all other header lines, are not
2817 protected by the signature.
2819 @item --emit-version
2820 @itemx --no-emit-version
2821 @opindex emit-version
2822 Force inclusion of the version string in ASCII armored output. If
2823 given once only the name of the program and the major number is
2824 emitted, given twice the minor is also emitted, given thrice
2825 the micro is added, and given four times an operating system identification
2826 is also emitted. @option{--no-emit-version} (default) disables the version
2829 @item --sig-notation @code{name=value}
2830 @itemx --cert-notation @code{name=value}
2831 @itemx -N, --set-notation @code{name=value}
2832 @opindex sig-notation
2833 @opindex cert-notation
2834 @opindex set-notation
2835 Put the name value pair into the signature as notation data.
2836 @code{name} must consist only of printable characters or spaces, and
2837 must contain a '@@' character in the form keyname@@domain.example.com
2838 (substituting the appropriate keyname and domain name, of course). This
2839 is to help prevent pollution of the IETF reserved notation
2840 namespace. The @option{--expert} flag overrides the '@@'
2841 check. @code{value} may be any printable string; it will be encoded in
2842 UTF-8, so you should check that your @option{--display-charset} is set
2843 correctly. If you prefix @code{name} with an exclamation mark (!), the
2844 notation data will be flagged as critical
2845 (rfc4880:5.2.3.16). @option{--sig-notation} sets a notation for data
2846 signatures. @option{--cert-notation} sets a notation for key signatures
2847 (certifications). @option{--set-notation} sets both.
2849 There are special codes that may be used in notation names. "%k" will
2850 be expanded into the key ID of the key being signed, "%K" into the
2851 long key ID of the key being signed, "%f" into the fingerprint of the
2852 key being signed, "%s" into the key ID of the key making the
2853 signature, "%S" into the long key ID of the key making the signature,
2854 "%g" into the fingerprint of the key making the signature (which might
2855 be a subkey), "%p" into the fingerprint of the primary key of the key
2856 making the signature, "%c" into the signature count from the OpenPGP
2857 smartcard, and "%%" results in a single "%". %k, %K, and %f are only
2858 meaningful when making a key signature (certification), and %c is only
2859 meaningful when using the OpenPGP smartcard.
2861 @item --sig-policy-url @code{string}
2862 @itemx --cert-policy-url @code{string}
2863 @itemx --set-policy-url @code{string}
2864 @opindex sig-policy-url
2865 @opindex cert-policy-url
2866 @opindex set-policy-url
2867 Use @code{string} as a Policy URL for signatures (rfc4880:5.2.3.20). If
2868 you prefix it with an exclamation mark (!), the policy URL packet will
2869 be flagged as critical. @option{--sig-policy-url} sets a policy url for
2870 data signatures. @option{--cert-policy-url} sets a policy url for key
2871 signatures (certifications). @option{--set-policy-url} sets both.
2873 The same %-expandos used for notation data are available here as well.
2875 @item --sig-keyserver-url @code{string}
2876 @opindex sig-keyserver-url
2877 Use @code{string} as a preferred keyserver URL for data signatures. If
2878 you prefix it with an exclamation mark (!), the keyserver URL packet
2879 will be flagged as critical.
2881 The same %-expandos used for notation data are available here as well.
2883 @item --set-filename @code{string}
2884 @opindex set-filename
2885 Use @code{string} as the filename which is stored inside messages.
2886 This overrides the default, which is to use the actual filename of the
2887 file being encrypted. Using the empty string for @code{string}
2888 effectively removes the filename from the output.
2890 @item --for-your-eyes-only
2891 @itemx --no-for-your-eyes-only
2892 @opindex for-your-eyes-only
2893 Set the `for your eyes only' flag in the message. This causes GnuPG to
2894 refuse to save the file unless the @option{--output} option is given,
2895 and PGP to use a "secure viewer" with a claimed Tempest-resistant font
2896 to display the message. This option overrides @option{--set-filename}.
2897 @option{--no-for-your-eyes-only} disables this option.
2899 @item --use-embedded-filename
2900 @itemx --no-use-embedded-filename
2901 @opindex use-embedded-filename
2902 Try to create a file with a name as embedded in the data. This can be
2903 a dangerous option as it enables overwriting files. Defaults to no.
2905 @item --cipher-algo @code{name}
2906 @opindex cipher-algo
2907 Use @code{name} as cipher algorithm. Running the program with the
2908 command @option{--version} yields a list of supported algorithms. If
2909 this is not used the cipher algorithm is selected from the preferences
2910 stored with the key. In general, you do not want to use this option as
2911 it allows you to violate the OpenPGP standard.
2912 @option{--personal-cipher-preferences} is the safe way to accomplish the
2915 @item --digest-algo @code{name}
2916 @opindex digest-algo
2917 Use @code{name} as the message digest algorithm. Running the program
2918 with the command @option{--version} yields a list of supported algorithms. In
2919 general, you do not want to use this option as it allows you to
2920 violate the OpenPGP standard. @option{--personal-digest-preferences} is the
2921 safe way to accomplish the same thing.
2923 @item --compress-algo @code{name}
2924 @opindex compress-algo
2925 Use compression algorithm @code{name}. "zlib" is RFC-1950 ZLIB
2926 compression. "zip" is RFC-1951 ZIP compression which is used by PGP.
2927 "bzip2" is a more modern compression scheme that can compress some
2928 things better than zip or zlib, but at the cost of more memory used
2929 during compression and decompression. "uncompressed" or "none"
2930 disables compression. If this option is not used, the default
2931 behavior is to examine the recipient key preferences to see which
2932 algorithms the recipient supports. If all else fails, ZIP is used for
2933 maximum compatibility.
2935 ZLIB may give better compression results than ZIP, as the compression
2936 window size is not limited to 8k. BZIP2 may give even better
2937 compression results than that, but will use a significantly larger
2938 amount of memory while compressing and decompressing. This may be
2939 significant in low memory situations. Note, however, that PGP (all
2940 versions) only supports ZIP compression. Using any algorithm other
2941 than ZIP or "none" will make the message unreadable with PGP. In
2942 general, you do not want to use this option as it allows you to
2943 violate the OpenPGP standard. @option{--personal-compress-preferences} is the
2944 safe way to accomplish the same thing.
2946 @item --cert-digest-algo @code{name}
2947 @opindex cert-digest-algo
2948 Use @code{name} as the message digest algorithm used when signing a
2949 key. Running the program with the command @option{--version} yields a
2950 list of supported algorithms. Be aware that if you choose an algorithm
2951 that GnuPG supports but other OpenPGP implementations do not, then some
2952 users will not be able to use the key signatures you make, or quite
2953 possibly your entire key.
2955 @item --disable-cipher-algo @code{name}
2956 @opindex disable-cipher-algo
2957 Never allow the use of @code{name} as cipher algorithm.
2958 The given name will not be checked so that a later loaded algorithm
2959 will still get disabled.
2961 @item --disable-pubkey-algo @code{name}
2962 @opindex disable-pubkey-algo
2963 Never allow the use of @code{name} as public key algorithm.
2964 The given name will not be checked so that a later loaded algorithm
2965 will still get disabled.
2967 @item --throw-keyids
2968 @itemx --no-throw-keyids
2969 @opindex throw-keyids
2970 Do not put the recipient key IDs into encrypted messages. This helps to
2971 hide the receivers of the message and is a limited countermeasure
2972 against traffic analysis.@footnote{Using a little social engineering
2973 anyone who is able to decrypt the message can check whether one of the
2974 other recipients is the one he suspects.} On the receiving side, it may
2975 slow down the decryption process because all available secret keys must
2976 be tried. @option{--no-throw-keyids} disables this option. This option
2977 is essentially the same as using @option{--hidden-recipient} for all
2980 @item --not-dash-escaped
2981 @opindex not-dash-escaped
2982 This option changes the behavior of cleartext signatures
2983 so that they can be used for patch files. You should not
2984 send such an armored file via email because all spaces
2985 and line endings are hashed too. You can not use this
2986 option for data which has 5 dashes at the beginning of a
2987 line, patch files don't have this. A special armor header
2988 line tells GnuPG about this cleartext signature option.
2990 @item --escape-from-lines
2991 @itemx --no-escape-from-lines
2992 @opindex escape-from-lines
2993 Because some mailers change lines starting with "From " to ">From " it
2994 is good to handle such lines in a special way when creating cleartext
2995 signatures to prevent the mail system from breaking the signature. Note
2996 that all other PGP versions do it this way too. Enabled by
2997 default. @option{--no-escape-from-lines} disables this option.
2999 @item --passphrase-repeat @code{n}
3000 @opindex passphrase-repeat
3001 Specify how many times @command{@gpgname} will request a new
3002 passphrase be repeated. This is useful for helping memorize a
3003 passphrase. Defaults to 1 repetition.
3005 @item --passphrase-fd @code{n}
3006 @opindex passphrase-fd
3007 Read the passphrase from file descriptor @code{n}. Only the first line
3008 will be read from file descriptor @code{n}. If you use 0 for @code{n},
3009 the passphrase will be read from STDIN. This can only be used if only
3010 one passphrase is supplied.
3012 Note that this passphrase is only used if the option @option{--batch}
3013 has also been given. This is different from GnuPG version 1.x.
3015 @item --passphrase-file @code{file}
3016 @opindex passphrase-file
3017 Read the passphrase from file @code{file}. Only the first line will
3018 be read from file @code{file}. This can only be used if only one
3019 passphrase is supplied. Obviously, a passphrase stored in a file is
3020 of questionable security if other users can read this file. Don't use
3021 this option if you can avoid it.
3022 Note that this passphrase is only used if the option @option{--batch}
3023 has also been given. This is different from GnuPG version 1.x.
3025 @item --passphrase @code{string}
3027 Use @code{string} as the passphrase. This can only be used if only one
3028 passphrase is supplied. Obviously, this is of very questionable
3029 security on a multi-user system. Don't use this option if you can
3031 Note that this passphrase is only used if the option @option{--batch}
3032 has also been given. This is different from GnuPG version 1.x.
3034 @item --pinentry-mode @code{mode}
3035 @opindex pinentry-mode
3036 Set the pinentry mode to @code{mode}. Allowed values for @code{mode}
3040 Use the default of the agent, which is @code{ask}.
3042 Force the use of the Pinentry.
3044 Emulate use of Pinentry's cancel button.
3046 Return a Pinentry error (``No Pinentry'').
3048 Redirect Pinentry queries to the caller. Note that in contrast to
3049 Pinentry the user is not prompted again if he enters a bad password.
3052 @item --command-fd @code{n}
3054 This is a replacement for the deprecated shared-memory IPC mode.
3055 If this option is enabled, user input on questions is not expected
3056 from the TTY but from the given file descriptor. It should be used
3057 together with @option{--status-fd}. See the file doc/DETAILS in the source
3058 distribution for details on how to use it.
3060 @item --command-file @code{file}
3061 @opindex command-file
3062 Same as @option{--command-fd}, except the commands are read out of file
3065 @item --allow-non-selfsigned-uid
3066 @itemx --no-allow-non-selfsigned-uid
3067 @opindex allow-non-selfsigned-uid
3068 Allow the import and use of keys with user IDs which are not
3069 self-signed. This is not recommended, as a non self-signed user ID is
3070 trivial to forge. @option{--no-allow-non-selfsigned-uid} disables.
3072 @item --allow-freeform-uid
3073 @opindex allow-freeform-uid
3074 Disable all checks on the form of the user ID while generating a new
3075 one. This option should only be used in very special environments as
3076 it does not ensure the de-facto standard format of user IDs.
3078 @item --ignore-time-conflict
3079 @opindex ignore-time-conflict
3080 GnuPG normally checks that the timestamps associated with keys and
3081 signatures have plausible values. However, sometimes a signature
3082 seems to be older than the key due to clock problems. This option
3083 makes these checks just a warning. See also @option{--ignore-valid-from} for
3084 timestamp issues on subkeys.
3086 @item --ignore-valid-from
3087 @opindex ignore-valid-from
3088 GnuPG normally does not select and use subkeys created in the future.
3089 This option allows the use of such keys and thus exhibits the
3090 pre-1.0.7 behaviour. You should not use this option unless there
3091 is some clock problem. See also @option{--ignore-time-conflict} for timestamp
3092 issues with signatures.
3094 @item --ignore-crc-error
3095 @opindex ignore-crc-error
3096 The ASCII armor used by OpenPGP is protected by a CRC checksum against
3097 transmission errors. Occasionally the CRC gets mangled somewhere on
3098 the transmission channel but the actual content (which is protected by
3099 the OpenPGP protocol anyway) is still okay. This option allows GnuPG
3100 to ignore CRC errors.
3102 @item --ignore-mdc-error
3103 @opindex ignore-mdc-error
3104 This option changes a MDC integrity protection failure into a warning.
3105 This can be useful if a message is partially corrupt, but it is
3106 necessary to get as much data as possible out of the corrupt message.
3107 However, be aware that a MDC protection failure may also mean that the
3108 message was tampered with intentionally by an attacker.
3110 @item --allow-weak-digest-algos
3111 @opindex allow-weak-digest-algos
3112 Signatures made with known-weak digest algorithms are normally
3113 rejected with an ``invalid digest algorithm'' message. This option
3114 allows the verification of signatures made with such weak algorithms.
3115 MD5 is the only digest algorithm considered weak by default. See also
3116 @option{--weak-digest} to reject other digest algorithms.
3118 @item --weak-digest @code{name}
3119 @opindex weak-digest
3120 Treat the specified digest algorithm as weak. Signatures made over
3121 weak digests algorithms are normally rejected. This option can be
3122 supplied multiple times if multiple algorithms should be considered
3123 weak. See also @option{--allow-weak-digest-algos} to disable
3124 rejection of weak digests. MD5 is always considered weak, and does
3125 not need to be listed explicitly.
3127 @item --no-default-keyring
3128 @opindex no-default-keyring
3129 Do not add the default keyrings to the list of keyrings. Note that
3130 GnuPG will not operate without any keyrings, so if you use this option
3131 and do not provide alternate keyrings via @option{--keyring} or
3132 @option{--secret-keyring}, then GnuPG will still use the default public or
3137 Do not add use any keyrings even if specified as options.
3140 @opindex skip-verify
3141 Skip the signature verification step. This may be
3142 used to make the decryption faster if the signature
3143 verification is not needed.
3145 @item --with-key-data
3146 @opindex with-key-data
3147 Print key listings delimited by colons (like @option{--with-colons}) and
3148 print the public key data.
3150 @item --fast-list-mode
3151 @opindex fast-list-mode
3152 Changes the output of the list commands to work faster; this is achieved
3153 by leaving some parts empty. Some applications don't need the user ID
3154 and the trust information given in the listings. By using this options
3155 they can get a faster listing. The exact behaviour of this option may
3156 change in future versions. If you are missing some information, don't
3161 This is not for normal use. Use the source to see for what it might be useful.
3163 @item --set-filesize
3164 @opindex set-filesize
3165 This is not for normal use. Use the source to see for what it might be useful.
3167 @item --show-session-key
3168 @opindex show-session-key
3169 Display the session key used for one message. See
3170 @option{--override-session-key} for the counterpart of this option.
3172 We think that Key Escrow is a Bad Thing; however the user should have
3173 the freedom to decide whether to go to prison or to reveal the content
3174 of one specific message without compromising all messages ever
3175 encrypted for one secret key.
3177 You can also use this option if you receive an encrypted message which
3178 is abusive or offensive, to prove to the administrators of the
3179 messaging system that the ciphertext transmitted corresponds to an
3180 inappropriate plaintext so they can take action against the offending
3183 @item --override-session-key @code{string}
3184 @itemx --override-session-key-fd @code{fd}
3185 @opindex override-session-key
3186 Don't use the public key but the session key @code{string} respective
3187 the session key taken from the first line read from file descriptor
3188 @code{fd}. The format of this string is the same as the one printed
3189 by @option{--show-session-key}. This option is normally not used but
3190 comes handy in case someone forces you to reveal the content of an
3191 encrypted message; using this option you can do this without handing
3192 out the secret key. Note that using @option{--override-session-key}
3193 may reveal the session key to all local users via the global process
3196 @item --ask-sig-expire
3197 @itemx --no-ask-sig-expire
3198 @opindex ask-sig-expire
3199 When making a data signature, prompt for an expiration time. If this
3200 option is not specified, the expiration time set via
3201 @option{--default-sig-expire} is used. @option{--no-ask-sig-expire}
3202 disables this option.
3204 @item --default-sig-expire
3205 @opindex default-sig-expire
3206 The default expiration time to use for signature expiration. Valid
3207 values are "0" for no expiration, a number followed by the letter d
3208 (for days), w (for weeks), m (for months), or y (for years) (for
3209 example "2m" for two months, or "5y" for five years), or an absolute
3210 date in the form YYYY-MM-DD. Defaults to "0".
3212 @item --ask-cert-expire
3213 @itemx --no-ask-cert-expire
3214 @opindex ask-cert-expire
3215 When making a key signature, prompt for an expiration time. If this
3216 option is not specified, the expiration time set via
3217 @option{--default-cert-expire} is used. @option{--no-ask-cert-expire}
3218 disables this option.
3220 @item --default-cert-expire
3221 @opindex default-cert-expire
3222 The default expiration time to use for key signature expiration.
3223 Valid values are "0" for no expiration, a number followed by the
3224 letter d (for days), w (for weeks), m (for months), or y (for years)
3225 (for example "2m" for two months, or "5y" for five years), or an
3226 absolute date in the form YYYY-MM-DD. Defaults to "0".
3228 @item --default-new-key-algo @var{string}
3229 @opindex default-new-key-algo @var{string}
3230 This option can be used to change the default algorithms for key
3231 generation. Note that the advanced key generation commands can always
3232 be used to specify a key algorithm directly. Please consult the
3233 source code to learn the syntax of @var{string}.
3235 @item --allow-secret-key-import
3236 @opindex allow-secret-key-import
3237 This is an obsolete option and is not used anywhere.
3239 @item --allow-multiple-messages
3240 @item --no-allow-multiple-messages
3241 @opindex allow-multiple-messages
3242 Allow processing of multiple OpenPGP messages contained in a single file
3243 or stream. Some programs that call GPG are not prepared to deal with
3244 multiple messages being processed together, so this option defaults to
3245 no. Note that versions of GPG prior to 1.4.7 always allowed multiple
3248 Warning: Do not use this option unless you need it as a temporary
3252 @item --enable-special-filenames
3253 @opindex enable-special-filenames
3254 This option enables a mode in which filenames of the form
3255 @file{-&n}, where n is a non-negative decimal number,
3256 refer to the file descriptor n and not to a file with that name.
3258 @item --no-expensive-trust-checks
3259 @opindex no-expensive-trust-checks
3260 Experimental use only.
3262 @item --preserve-permissions
3263 @opindex preserve-permissions
3264 Don't change the permissions of a secret keyring back to user
3265 read/write only. Use this option only if you really know what you are doing.
3267 @item --default-preference-list @code{string}
3268 @opindex default-preference-list
3269 Set the list of default preferences to @code{string}. This preference
3270 list is used for new keys and becomes the default for "setpref" in the
3273 @item --default-keyserver-url @code{name}
3274 @opindex default-keyserver-url
3275 Set the default keyserver URL to @code{name}. This keyserver will be
3276 used as the keyserver URL when writing a new self-signature on a key,
3277 which includes key generation and changing preferences.
3280 @opindex list-config
3281 Display various internal configuration parameters of GnuPG. This option
3282 is intended for external programs that call GnuPG to perform tasks, and
3283 is thus not generally useful. See the file @file{doc/DETAILS} in the
3284 source distribution for the details of which configuration items may be
3285 listed. @option{--list-config} is only usable with
3286 @option{--with-colons} set.
3288 @item --list-gcrypt-config
3289 @opindex list-gcrypt-config
3290 Display various internal configuration parameters of Libgcrypt.
3292 @item --gpgconf-list
3293 @opindex gpgconf-list
3294 This command is similar to @option{--list-config} but in general only
3295 internally used by the @command{gpgconf} tool.
3297 @item --gpgconf-test
3298 @opindex gpgconf-test
3299 This is more or less dummy action. However it parses the configuration
3300 file and returns with failure if the configuration file would prevent
3301 @command{@gpgname} from startup. Thus it may be used to run a syntax check
3302 on the configuration file.
3306 @c *******************************
3307 @c ******* Deprecated ************
3308 @c *******************************
3309 @node Deprecated Options
3310 @subsection Deprecated options
3315 @itemx --no-show-photos
3316 @opindex show-photos
3317 Causes @option{--list-keys}, @option{--list-signatures},
3318 @option{--list-public-keys}, @option{--list-secret-keys}, and verifying
3319 a signature to also display the photo ID attached to the key, if
3320 any. See also @option{--photo-viewer}. These options are deprecated. Use
3321 @option{--list-options [no-]show-photos} and/or @option{--verify-options
3322 [no-]show-photos} instead.
3324 @item --show-keyring
3325 @opindex show-keyring
3326 Display the keyring name at the head of key listings to show which
3327 keyring a given key resides on. This option is deprecated: use
3328 @option{--list-options [no-]show-keyring} instead.
3330 @item --always-trust
3331 @opindex always-trust
3332 Identical to @option{--trust-model always}. This option is deprecated.
3334 @item --show-notation
3335 @itemx --no-show-notation
3336 @opindex show-notation
3337 Show signature notations in the @option{--list-signatures} or @option{--check-signatures} listings
3338 as well as when verifying a signature with a notation in it. These
3339 options are deprecated. Use @option{--list-options [no-]show-notation}
3340 and/or @option{--verify-options [no-]show-notation} instead.
3342 @item --show-policy-url
3343 @itemx --no-show-policy-url
3344 @opindex show-policy-url
3345 Show policy URLs in the @option{--list-signatures} or @option{--check-signatures}
3346 listings as well as when verifying a signature with a policy URL in
3347 it. These options are deprecated. Use @option{--list-options
3348 [no-]show-policy-url} and/or @option{--verify-options
3349 [no-]show-policy-url} instead.
3355 @c *******************************************
3356 @c *************** ****************
3357 @c *************** FILES ****************
3358 @c *************** ****************
3359 @c *******************************************
3361 @node GPG Configuration
3362 @section Configuration files
3364 There are a few configuration files to control certain aspects of
3365 @command{@gpgname}'s operation. Unless noted, they are expected in the
3366 current home directory (@pxref{option --homedir}).
3372 This is the standard configuration file read by @command{@gpgname} on
3373 startup. It may contain any valid long option; the leading two dashes
3374 may not be entered and the option may not be abbreviated. This default
3375 name may be changed on the command line (@pxref{gpg-option --options}).
3376 You should backup this file.
3380 Note that on larger installations, it is useful to put predefined files
3381 into the directory @file{@value{SYSCONFSKELDIR}} so that
3382 newly created users start up with a working configuration.
3383 For existing users a small
3384 helper script is provided to create these files (@pxref{addgnupghome}).
3386 For internal purposes @command{@gpgname} creates and maintains a few other
3387 files; They all live in in the current home directory (@pxref{option
3388 --homedir}). Only the @command{@gpgname} program may modify these files.
3394 This is the default home directory which is used if neither the
3395 environment variable @code{GNUPGHOME} nor the option
3396 @option{--homedir} is given.
3398 @item ~/.gnupg/pubring.gpg
3399 @efindex pubring.gpg
3400 The public keyring. You should backup this file.
3402 @item ~/.gnupg/pubring.gpg.lock
3403 The lock file for the public keyring.
3405 @item ~/.gnupg/pubring.kbx
3406 @efindex pubring.kbx
3407 The public keyring using a different format. This file is shared
3408 with @command{gpgsm}. You should backup this file.
3410 @item ~/.gnupg/pubring.kbx.lock
3411 The lock file for @file{pubring.kbx}.
3413 @item ~/.gnupg/secring.gpg
3414 @efindex secring.gpg
3415 A secret keyring as used by GnuPG versions before 2.1. It is not
3416 used by GnuPG 2.1 and later.
3418 @item ~/.gnupg/secring.gpg.lock
3419 The lock file for the secret keyring.
3421 @item ~/.gnupg/.gpg-v21-migrated
3422 @efindex .gpg-v21-migrated
3423 File indicating that a migration to GnuPG 2.1 has been done.
3425 @item ~/.gnupg/trustdb.gpg
3426 @efindex trustdb.gpg
3427 The trust database. There is no need to backup this file; it is better
3428 to backup the ownertrust values (@pxref{option --export-ownertrust}).
3430 @item ~/.gnupg/trustdb.gpg.lock
3431 The lock file for the trust database.
3433 @item ~/.gnupg/random_seed
3434 @efindex random_seed
3435 A file used to preserve the state of the internal random pool.
3437 @item ~/.gnupg/openpgp-revocs.d/
3438 @efindex openpgp-revocs.d
3439 This is the directory where gpg stores pre-generated revocation
3440 certificates. The file name corresponds to the OpenPGP fingerprint of
3441 the respective key. It is suggested to backup those certificates and
3442 if the primary private key is not stored on the disk to move them to
3443 an external storage device. Anyone who can access theses files is
3444 able to revoke the corresponding key. You may want to print them out.
3445 You should backup all files in this directory and take care to keep
3446 this backup closed away.
3448 @item @value{DATADIR}/options.skel
3449 @efindex options.skel
3450 The skeleton options file.
3454 Operation is further controlled by a few environment variables:
3460 Used to locate the default home directory.
3464 If set directory used instead of "~/.gnupg".
3466 @item GPG_AGENT_INFO
3467 This variable is obsolete; it was used by GnuPG versions before 2.1.
3469 @item PINENTRY_USER_DATA
3470 @efindex PINENTRY_USER_DATA
3471 This value is passed via gpg-agent to pinentry. It is useful to convey
3472 extra information to a custom pinentry.
3478 Used to size some displays to the full size of the screen.
3482 Apart from its use by GNU, it is used in the W32 version to override the
3483 language selection done through the Registry. If used and set to a
3484 valid and available language name (@var{langid}), the file with the
3485 translation is loaded from
3486 @code{@var{gpgdir}/gnupg.nls/@var{langid}.mo}. Here @var{gpgdir} is the
3487 directory out of which the gpg binary has been loaded. If it can't be
3488 loaded the Registry is tried and as last resort the native Windows
3489 locale system is used.
3494 @c *******************************************
3495 @c *************** ****************
3496 @c *************** EXAMPLES ****************
3497 @c *************** ****************
3498 @c *******************************************
3505 @item gpg -se -r @code{Bob} @code{file}
3506 sign and encrypt for user Bob
3508 @item gpg --clear-sign @code{file}
3509 make a cleartext signature
3511 @item gpg -sb @code{file}
3512 make a detached signature
3514 @item gpg -u 0x12345678 -sb @code{file}
3515 make a detached signature with the key 0x12345678
3517 @item gpg --list-keys @code{user_ID}
3520 @item gpg --fingerprint @code{user_ID}
3523 @item gpg --verify @code{pgpfile}
3524 @itemx gpg --verify @code{sigfile} [@code{datafile}]
3525 Verify the signature of the file but do not output the data unless
3526 requested. The second form is used for detached signatures, where
3527 @code{sigfile} is the detached signature (either ASCII armored or
3528 binary) and @code{datafile} are the signed data; if this is not given, the name of the
3529 file holding the signed data is constructed by cutting off the
3530 extension (".asc" or ".sig") of @code{sigfile} or by asking the user
3531 for the filename. If the option @option{--output} is also used the
3532 signed data is written to the file specified by that option; use
3533 @code{-} to write the signed data to stdout.
3537 @c *******************************************
3538 @c *************** ****************
3539 @c *************** USER ID ****************
3540 @c *************** ****************
3541 @c *******************************************
3542 @mansect how to specify a user id
3544 @include specify-user-id.texi
3547 @mansect filter expressions
3548 @chapheading FILTER EXPRESSIONS
3550 The options @option{--import-filter} and @option{--export-filter} use
3551 expressions with this syntax (square brackets indicate an optional
3552 part and curly braces a repetition, white space between the elements
3557 [lc] @{[@{flag@}] PROPNAME op VALUE [lc]@}
3561 The name of a property (@var{PROPNAME}) may only consist of letters,
3562 digits and underscores. The description for the filter type
3563 describes which properties are defined. If an undefined property is
3564 used it evaluates to the empty string. Unless otherwise noted, the
3565 @var{VALUE} must always be given and may not be the empty string. No
3566 quoting is defined for the value, thus the value may not contain the
3567 strings @code{&&} or @code{||}, which are used as logical connection
3568 operators. The flag @code{--} can be used to remove this restriction.
3570 Numerical values are computed as long int; standard C notation
3571 applies. @var{lc} is the logical connection operator; either
3572 @code{&&} for a conjunction or @code{||} for a disjunction. A
3573 conjunction is assumed at the begin of an expression. Conjunctions
3574 have higher precedence than disjunctions. If @var{VALUE} starts with
3575 one of the characters used in any @var{op} a space after the
3576 @var{op} is required.
3579 The supported operators (@var{op}) are:
3584 Substring must match.
3587 Substring must not match.
3590 The full string must match.
3593 The full string must not match.
3596 The numerical value must match.
3599 The numerical value must not match.
3602 The numerical value of the field must be LE than the value.
3605 The numerical value of the field must be LT than the value.
3608 The numerical value of the field must be GT than the value.
3611 The numerical value of the field must be GE than the value.
3614 The string value of the field must be less or equal than the value.
3617 The string value of the field must be less than the value.
3620 The string value of the field must be greater than the value.
3623 The string value of the field must be greater or equal than the value.
3626 True if value is not empty (no value allowed).
3629 True if value is empty (no value allowed).
3632 Alias for "PROPNAME != 0" (no value allowed).
3635 Alias for "PROPNAME == 0" (no value allowed).
3640 Values for @var{flag} must be space separated. The supported flags
3645 @var{VALUE} spans to the end of the expression.
3647 The string match in this part is done case-sensitive.
3650 The filter options concatenate several specifications for a filter of
3651 the same type. For example the four options in this example:
3655 --import-option keep-uid="uid =~ Alfa"
3656 --import-option keep-uid="&& uid !~ Test"
3657 --import-option keep-uid="|| uid =~ Alpha"
3658 --import-option keep-uid="uid !~ Test"
3663 which is equivalent to
3668 keep-uid="uid =~ Alfa" && uid !~ Test" || uid =~ Alpha" && "uid !~ Test"
3672 imports only the user ids of a key containing the strings "Alfa"
3673 or "Alpha" but not the string "test".
3676 @mansect return value
3677 @chapheading RETURN VALUE
3679 The program returns 0 if everything was fine, 1 if at least
3680 a signature was bad, and other error codes for fatal errors.
3683 @chapheading WARNINGS
3685 Use a *good* password for your user account and a *good* passphrase
3686 to protect your secret key. This passphrase is the weakest part of the
3687 whole system. Programs to do dictionary attacks on your secret keyring
3688 are very easy to write and so you should protect your "~/.gnupg/"
3689 directory very well.
3691 Keep in mind that, if this program is used over a network (telnet), it
3692 is *very* easy to spy out your passphrase!
3694 If you are going to verify detached signatures, make sure that the
3695 program knows about it; either give both filenames on the command line
3696 or use @samp{-} to specify STDIN.
3698 @mansect interoperability
3699 @chapheading INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS
3701 GnuPG tries to be a very flexible implementation of the OpenPGP
3702 standard. In particular, GnuPG implements many of the optional parts
3703 of the standard, such as the SHA-512 hash, and the ZLIB and BZIP2
3704 compression algorithms. It is important to be aware that not all
3705 OpenPGP programs implement these optional algorithms and that by
3706 forcing their use via the @option{--cipher-algo},
3707 @option{--digest-algo}, @option{--cert-digest-algo}, or
3708 @option{--compress-algo} options in GnuPG, it is possible to create a
3709 perfectly valid OpenPGP message, but one that cannot be read by the
3712 There are dozens of variations of OpenPGP programs available, and each
3713 supports a slightly different subset of these optional algorithms.
3714 For example, until recently, no (unhacked) version of PGP supported
3715 the BLOWFISH cipher algorithm. A message using BLOWFISH simply could
3716 not be read by a PGP user. By default, GnuPG uses the standard
3717 OpenPGP preferences system that will always do the right thing and
3718 create messages that are usable by all recipients, regardless of which
3719 OpenPGP program they use. Only override this safe default if you
3720 really know what you are doing.
3722 If you absolutely must override the safe default, or if the preferences
3723 on a given key are invalid for some reason, you are far better off using
3724 the @option{--pgp6}, @option{--pgp7}, or @option{--pgp8} options. These
3725 options are safe as they do not force any particular algorithms in
3726 violation of OpenPGP, but rather reduce the available algorithms to a
3732 On older systems this program should be installed as setuid(root). This
3733 is necessary to lock memory pages. Locking memory pages prevents the
3734 operating system from writing memory pages (which may contain
3735 passphrases or other sensitive material) to disk. If you get no
3736 warning message about insecure memory your operating system supports
3737 locking without being root. The program drops root privileges as soon
3738 as locked memory is allocated.
3740 Note also that some systems (especially laptops) have the ability to
3741 ``suspend to disk'' (also known as ``safe sleep'' or ``hibernate'').
3742 This writes all memory to disk before going into a low power or even
3743 powered off mode. Unless measures are taken in the operating system
3744 to protect the saved memory, passphrases or other sensitive material
3745 may be recoverable from it later.
3747 Before you report a bug you should first search the mailing list
3748 archives for similar problems and second check whether such a bug has
3749 already been reported to our bug tracker at http://bugs.gnupg.org .
3751 @c *******************************************
3752 @c *************** **************
3753 @c *************** UNATTENDED **************
3754 @c *************** **************
3755 @c *******************************************
3757 @node Unattended Usage of GPG
3758 @section Unattended Usage
3760 @command{@gpgname} is often used as a backend engine by other software. To help
3761 with this a machine interface has been defined to have an unambiguous
3762 way to do this. The options @option{--status-fd} and @option{--batch}
3763 are almost always required for this.
3766 * Programmatic use of GnuPG:: Programmatic use of GnuPG
3767 * Ephemeral home directories:: Ephemeral home directories
3768 * The quick key manipulation interface:: The quick key manipulation interface
3769 * Unattended GPG key generation:: Unattended key generation
3773 @node Programmatic use of GnuPG
3774 @subsection Programmatic use of GnuPG
3776 Please consider using GPGME instead of calling @command{@gpgname}
3777 directly. GPGME offers a stable, backend-independent interface for
3778 many cryptographic operations. It supports OpenPGP and S/MIME, and
3779 also allows interaction with various GnuPG components.
3781 GPGME provides a C-API, and comes with bindings for C++, Qt, and
3782 Python. Bindings for other languages are available.
3784 @node Ephemeral home directories
3785 @subsection Ephemeral home directories
3787 Sometimes you want to contain effects of some operation, for example
3788 you want to import a key to inspect it, but you do not want this key
3789 to be added to your keyring. In earlier versions of GnuPG, it was
3790 possible to specify alternate keyring files for both public and secret
3791 keys. In modern GnuPG versions, however, we changed how secret keys
3792 are stored in order to better protect secret key material, and it was
3793 not possible to preserve this interface.
3795 The preferred way to do this is to use ephemeral home directories.
3796 This technique works across all versions of GnuPG.
3798 Create a temporary directory, create (or copy) a configuration that
3799 meets your needs, make @command{@gpgname} use this directory either
3800 using the environment variable @var{GNUPGHOME}, or the option
3801 @option{--homedir}. GPGME supports this too on a per-context basis,
3802 by modifying the engine info of contexts. Now execute whatever
3803 operation you like, import and export key material as necessary. Once
3804 finished, you can delete the directory. All GnuPG backend services
3805 that were started will detect this and shut down.
3807 @node The quick key manipulation interface
3808 @subsection The quick key manipulation interface
3810 Recent versions of GnuPG have an interface to manipulate keys without
3811 using the interactive command @option{--edit-key}. This interface was
3812 added mainly for the benefit of GPGME (please consider using GPGME,
3813 see the manual subsection ``Programmatic use of GnuPG''). This
3814 interface is described in the subsection ``How to manage your keys''.
3816 @node Unattended GPG key generation
3817 @subsection Unattended key generation
3819 The command @option{--generate-key} may be used along with the option
3820 @option{--batch} for unattended key generation. This is the most
3821 flexible way of generating keys, but it is also the most complex one.
3822 Consider using the quick key manipulation interface described in the
3823 previous subsection ``The quick key manipulation interface''.
3825 The parameters for the key are either read from stdin or given as a
3826 file on the command line. The format of the parameter file is as
3830 @item Text only, line length is limited to about 1000 characters.
3831 @item UTF-8 encoding must be used to specify non-ASCII characters.
3832 @item Empty lines are ignored.
3833 @item Leading and trailing while space is ignored.
3834 @item A hash sign as the first non white space character indicates
3836 @item Control statements are indicated by a leading percent sign, the
3837 arguments are separated by white space from the keyword.
3838 @item Parameters are specified by a keyword, followed by a colon. Arguments
3839 are separated by white space.
3841 The first parameter must be @samp{Key-Type}; control statements may be
3844 The order of the parameters does not matter except for @samp{Key-Type}
3845 which must be the first parameter. The parameters are only used for
3846 the generated keyblock (primary and subkeys); parameters from previous
3847 sets are not used. Some syntactically checks may be performed.
3849 Key generation takes place when either the end of the parameter file
3850 is reached, the next @samp{Key-Type} parameter is encountered or at the
3851 control statement @samp{%commit} is encountered.
3859 @item %echo @var{text}
3860 Print @var{text} as diagnostic.
3863 Suppress actual key generation (useful for syntax checking).
3866 Perform the key generation. Note that an implicit commit is done at
3867 the next @asis{Key-Type} parameter.
3869 @item %pubring @var{filename}
3870 Do not write the key to the default or commandline given keyring but
3871 to @var{filename}. This must be given before the first commit to take
3872 place, duplicate specification of the same filename is ignored, the
3873 last filename before a commit is used. The filename is used until a
3874 new filename is used (at commit points) and all keys are written to
3875 that file. If a new filename is given, this file is created (and
3876 overwrites an existing one).
3878 See the previous subsection ``Ephemeral home directories'' for a more
3879 robust way to contain side-effects.
3881 @item %secring @var{filename}
3882 This option is a no-op for GnuPG 2.1 and later.
3884 See the previous subsection ``Ephemeral home directories''.
3886 @item %ask-passphrase
3887 @itemx %no-ask-passphrase
3888 This option is a no-op for GnuPG 2.1 and later.
3890 @item %no-protection
3891 Using this option allows the creation of keys without any passphrase
3892 protection. This option is mainly intended for regression tests.
3894 @item %transient-key
3895 If given the keys are created using a faster and a somewhat less
3896 secure random number generator. This option may be used for keys
3897 which are only used for a short time and do not require full
3898 cryptographic strength. It takes only effect if used together with
3899 the control statement @samp{%no-protection}.
3908 @item Key-Type: @var{algo}
3909 Starts a new parameter block by giving the type of the primary
3910 key. The algorithm must be capable of signing. This is a required
3911 parameter. @var{algo} may either be an OpenPGP algorithm number or a
3912 string with the algorithm name. The special value @samp{default} may
3913 be used for @var{algo} to create the default key type; in this case a
3914 @samp{Key-Usage} shall not be given and @samp{default} also be used
3915 for @samp{Subkey-Type}.
3917 @item Key-Length: @var{nbits}
3918 The requested length of the generated key in bits. The default is
3919 returned by running the command @samp{@gpgname --gpgconf-list}.
3921 @item Key-Grip: @var{hexstring}
3922 This is optional and used to generate a CSR or certificate for an
3923 already existing key. Key-Length will be ignored when given.
3925 @item Key-Usage: @var{usage-list}
3926 Space or comma delimited list of key usages. Allowed values are
3927 @samp{encrypt}, @samp{sign}, and @samp{auth}. This is used to
3928 generate the key flags. Please make sure that the algorithm is
3929 capable of this usage. Note that OpenPGP requires that all primary
3930 keys are capable of certification, so no matter what usage is given
3931 here, the @samp{cert} flag will be on. If no @samp{Key-Usage} is
3932 specified and the @samp{Key-Type} is not @samp{default}, all allowed
3933 usages for that particular algorithm are used; if it is not given but
3934 @samp{default} is used the usage will be @samp{sign}.
3936 @item Subkey-Type: @var{algo}
3937 This generates a secondary key (subkey). Currently only one subkey
3938 can be handled. See also @samp{Key-Type} above.
3940 @item Subkey-Length: @var{nbits}
3941 Length of the secondary key (subkey) in bits. The default is returned
3942 by running the command @samp{@gpgname --gpgconf-list}.
3944 @item Subkey-Usage: @var{usage-list}
3945 Key usage lists for a subkey; similar to @samp{Key-Usage}.
3947 @item Passphrase: @var{string}
3948 If you want to specify a passphrase for the secret key, enter it here.
3949 Default is to use the Pinentry dialog to ask for a passphrase.
3951 @item Name-Real: @var{name}
3952 @itemx Name-Comment: @var{comment}
3953 @itemx Name-Email: @var{email}
3954 The three parts of a user name. Remember to use UTF-8 encoding here.
3955 If you don't give any of them, no user ID is created.
3957 @item Expire-Date: @var{iso-date}|(@var{number}[d|w|m|y])
3958 Set the expiration date for the key (and the subkey). It may either
3959 be entered in ISO date format (e.g. "20000815T145012") or as number of
3960 days, weeks, month or years after the creation date. The special
3961 notation "seconds=N" is also allowed to specify a number of seconds
3962 since creation. Without a letter days are assumed. Note that there
3963 is no check done on the overflow of the type used by OpenPGP for
3964 timestamps. Thus you better make sure that the given value make
3965 sense. Although OpenPGP works with time intervals, GnuPG uses an
3966 absolute value internally and thus the last year we can represent is
3969 @item Creation-Date: @var{iso-date}
3970 Set the creation date of the key as stored in the key information and
3971 which is also part of the fingerprint calculation. Either a date like
3972 "1986-04-26" or a full timestamp like "19860426T042640" may be used.
3973 The time is considered to be UTC. The special notation "seconds=N"
3974 may be used to directly specify a the number of seconds since Epoch
3975 (Unix time). If it is not given the current time is used.
3977 @item Preferences: @var{string}
3978 Set the cipher, hash, and compression preference values for this key.
3979 This expects the same type of string as the sub-command @samp{setpref}
3980 in the @option{--edit-key} menu.
3982 @item Revoker: @var{algo}:@var{fpr} [sensitive]
3983 Add a designated revoker to the generated key. Algo is the public key
3984 algorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.)
3985 @var{fpr} is the fingerprint of the designated revoker. The optional
3986 @samp{sensitive} flag marks the designated revoker as sensitive
3987 information. Only v4 keys may be designated revokers.
3989 @item Keyserver: @var{string}
3990 This is an optional parameter that specifies the preferred keyserver
3993 @item Handle: @var{string}
3994 This is an optional parameter only used with the status lines
3995 KEY_CREATED and KEY_NOT_CREATED. @var{string} may be up to 100
3996 characters and should not contain spaces. It is useful for batch key
3997 generation to associate a key parameter block with a status line.
4002 Here is an example on how to create a key in an ephemeral home directory:
4004 $ export GNUPGHOME="$(mktemp -d)"
4006 %echo Generating a basic OpenPGP key
4011 Name-Real: Joe Tester
4012 Name-Comment: with stupid passphrase
4013 Name-Email: joe@@foo.bar
4016 # Do a commit here, so that we can later print "done" :-)
4020 $ @gpgname --batch --generate-key foo
4022 $ @gpgname --list-secret-keys
4023 /tmp/tmp.0NQxB74PEf/pubring.kbx
4024 -------------------------------
4025 sec dsa1024 2016-12-16 [SCA]
4026 768E895903FC1C44045C8CB95EEBDB71E9E849D0
4027 uid [ultimate] Joe Tester (with stupid passphrase) <joe@@foo.bar>
4028 ssb elg1024 2016-12-16 [E]
4032 If you want to create a key with the default algorithms you would use
4035 %echo Generating a default key
4037 Subkey-Type: default
4038 Name-Real: Joe Tester
4039 Name-Comment: with stupid passphrase
4040 Name-Email: joe@@foo.bar
4043 # Do a commit here, so that we can later print "done" :-)
4055 @command{gpg-agent}(1)
4057 @include see-also-note.texi