1GPG(1) GNU Privacy Guard GPG(1)
2
6 gpg - OpenPGP encryption and signing tool
7
9 gpg [--homedir dir] [--options file] [options] command [args]
10
14 gpg is the OpenPGP part of the GNU Privacy Guard (GnuPG). It is a tool
15 to provide digital encryption and signing services using the OpenPGP
16 standard. gpg features complete key management and all bells and whis‐
17 tles you can expect from a decent OpenPGP implementation.
18 This is the standalone version of gpg. For desktop use you should con‐
20 sider using gpg2 ([On some platforms gpg2 is installed under the name
21 gpg]).
22
31 The program returns 0 if everything was fine, 1 if at least a signature
32 was bad, and other error codes for fatal errors.
33
36 Use a *good* password for your user account and a *good* passphrase to
37 protect your secret key. This passphrase is the weakest part of the
38 whole system. Programs to do dictionary attacks on your secret keyring
39 are very easy to write and so you should protect your "~/.gnupg/"
40 directory very well.
41 Keep in mind that, if this program is used over a network (telnet), it
43 is *very* easy to spy out your passphrase!
44 If you are going to verify detached signatures, make sure that the pro‐
46 gram knows about it; either give both filenames on the command line or
47 use '-'' to specify STDIN.
48
51 GnuPG tries to be a very flexible implementation of the OpenPGP stan‐
52 dard. In particular, GnuPG implements many of the optional parts of the
53 standard, such as the SHA-512 hash, and the ZLIB and BZIP2 compression
54 algorithms. It is important to be aware that not all OpenPGP programs
55 implement these optional algorithms and that by forcing their use via
56 the --cipher-algo, --digest-algo, --cert-digest-algo, or --compress-
57 algo options in GnuPG, it is possible to create a perfectly valid
58 OpenPGP message, but one that cannot be read by the intended recipient.
59 There are dozens of variations of OpenPGP programs available, and each
61 supports a slightly different subset of these optional algorithms. For
62 example, until recently, no (unhacked) version of PGP supported the
63 BLOWFISH cipher algorithm. A message using BLOWFISH simply could not be
64 read by a PGP user. By default, GnuPG uses the standard OpenPGP prefer‐
65 ences system that will always do the right thing and create messages
66 that are usable by all recipients, regardless of which OpenPGP program
67 they use. Only override this safe default if you really know what you
68 are doing.
69 If you absolutely must override the safe default, or if the preferences
71 on a given key are invalid for some reason, you are far better off
72 using the --pgp6, --pgp7, or --pgp8 options. These options are safe as
73 they do not force any particular algorithms in violation of OpenPGP,
74 but rather reduce the available algorithms to a "PGP-safe" list.
75
78 Commands are not distinguished from options except for the fact that
79 only one command is allowed.
80 gpg may be run with no commands, in which case it will perform a rea‐
82 sonable action depending on the type of file it is given as input (an
83 encrypted message is decrypted, a signature is verified, a file con‐
84 taining keys is listed).
85 Please remember that option as well as command parsing stops as soon as
87 a non-option is encountered, you can explicitly stop parsing by using
88 the special option --.
89 Commands not specific to the function
96 --version
100 Print the program version and licensing information. Note that
101 you cannot abbreviate this command.
102 --help
105 -h Print a usage message summarizing the most useful command line
107 options. Note that you cannot abbreviate this command.
108 --warranty
111 Print warranty information.
112 --dump-options
115 Print a list of all available options and commands. Note that
116 you cannot abbreviate this command.
117 Commands to select the type of operation
122 --sign
128 -s Make a signature. This command may be combined with --encrypt
130 (for a signed and encrypted message), --symmetric (for a signed
131 and symmetrically encrypted message), or --encrypt and --symmet‐
132 ric together (for a signed message that may be decrypted via a
133 secret key or a passphrase). The key to be used for signing is
134 chosen by default or can be set with the --local-user and
135 --default-key options.
136 --clearsign
139 Make a clear text signature. The content in a clear text signa‐
140 ture is readable without any special software. OpenPGP software
141 is only needed to verify the signature. Clear text signatures
142 may modify end-of-line whitespace for platform independence and
143 are not intended to be reversible. The key to be used for sign‐
144 ing is chosen by default or can be set with the --local-user and
145 --default-key options.
146 --detach-sign
150 -b Make a detached signature.
152 --encrypt
155 -e Encrypt data. This option may be combined with --sign (for a
157 signed and encrypted message), --symmetric (for a message that
158 may be decrypted via a secret key or a passphrase), or --sign
159 and --symmetric together (for a signed message that may be
160 decrypted via a secret key or a passphrase).
161 --symmetric
164 -c Encrypt with a symmetric cipher using a passphrase. The default
166 symmetric cipher used is CAST5, but may be chosen with the
167 --cipher-algo option. This option may be combined with --sign
168 (for a signed and symmetrically encrypted message), --encrypt
169 (for a message that may be decrypted via a secret key or a
170 passphrase), or --sign and --encrypt together (for a signed mes‐
171 sage that may be decrypted via a secret key or a passphrase).
172 --store
175 Store only (make a simple RFC1991 literal data packet).
176 --decrypt
179 -d Decrypt the file given on the command line (or STDIN if no file
181 is specified) and write it to STDOUT (or the file specified with
182 --output). If the decrypted file is signed, the signature is
183 also verified. This command differs from the default operation,
184 as it never writes to the filename which is included in the file
185 and it rejects files which don't begin with an encrypted mes‐
186 sage.
187 --verify
190 Assume that the first argument is a signed file or a detached
191 signature and verify it without generating any output. With no
192 arguments, the signature packet is read from STDIN. If only a
193 sigfile is given, it may be a complete signature or a detached
194 signature, in which case the signed stuff is expected in a file
195 without the ".sig" or ".asc" extension. With more than 1 argu‐
196 ment, the first should be a detached signature and the remaining
197 files are the signed stuff. To read the signed stuff from STDIN,
198 use '-'' as the second filename. For security reasons a
199 detached signature cannot read the signed material from STDIN
200 without denoting it in the above way.
201 --multifile
204 This modifies certain other commands to accept multiple files
205 for processing on the command line or read from STDIN with each
206 filename on a separate line. This allows for many files to be
207 processed at once. --multifile may currently be used along with
208 --verify, --encrypt, and --decrypt. Note that --multifile --ver‐
209 ify may not be used with detached signatures.
210 --verify-files
213 Identical to --multifile --verify.
214 --encrypt-files
217 Identical to --multifile --encrypt.
218 --decrypt-files
221 Identical to --multifile --decrypt.
222 --list-keys
225 -k
227 --list-public-keys
229 List all keys from the public keyrings, or just the keys given
230 on the command line. -k is slightly different from --list-keys
231 in that it allows only for one argument and takes the second
232 argument as the keyring to search. This is for command line
233 compatibility with PGP 2 and has been removed in gpg2.
234 Avoid using the output of this command in scripts or other pro‐
236 grams as it is likely to change as GnuPG changes. See --with-
237 colons for a machine-parseable key listing command that is
238 appropriate for use in scripts and other programs.
239 --list-secret-keys
242 -K List all keys from the secret keyrings, or just the ones given
244 on the command line. A # after the letters sec means that the
245 secret key is not usable (for example, if it was created via
246 --export-secret-subkeys).
247 --list-sigs
250 Same as --list-keys, but the signatures are listed too.
251 For each signature listed, there are several flags in between
253 the "sig" tag and keyid. These flags give additional information
254 about each signature. From left to right, they are the numbers
255 1-3 for certificate check level (see --ask-cert-level), "L" for
256 a local or non-exportable signature (see --lsign-key), "R" for a
257 nonRevocable signature (see the --edit-key command "nrsign"),
258 "P" for a signature that contains a policy URL (see --cert-pol‐
259 icy-url), "N" for a signature that contains a notation (see
260 --cert-notation), "X" for an eXpired signature (see --ask-cert-
261 expire), and the numbers 1-9 or "T" for 10 and above to indicate
262 trust signature levels (see the --edit-key command "tsign").
263 --check-sigs
266 Same as --list-sigs, but the signatures are verified. Note that
267 for performance reasons the revocation status of a signing key
268 is not shown.
269 The status of the verification is indicated by a flag directly
271 following the "sig" tag (and thus before the flags described
272 above for --list-sigs). A "!" indicates that the signature has
273 been successfully verified, a "-" denotes a bad signature and a
274 "%" is used if an error occurred while checking the signature
275 (e.g. a non supported algorithm).
276 --fingerprint
281 List all keys (or the specified ones) along with their finger‐
282 prints. This is the same output as --list-keys but with the
283 additional output of a line with the fingerprint. May also be
284 combined with --list-sigs or --check-sigs. If this command is
285 given twice, the fingerprints of all secondary keys are listed
286 too.
287 --list-packets
290 List only the sequence of packets. This is mainly useful for
291 debugging.
292 --card-edit
296 Present a menu to work with a smartcard. The subcommand "help"
297 provides an overview on available commands. For a detailed
298 description, please see the Card HOWTO at
299 http://www.gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .
300 --card-status
303 Show the content of the smart card.
304 --change-pin
307 Present a menu to allow changing the PIN of a smartcard. This
308 functionality is also available as the subcommand "passwd" with
309 the --card-edit command.
310 --delete-key name
313 Remove key from the public keyring. In batch mode either --yes
314 is required or the key must be specified by fingerprint. This is
315 a safeguard against accidental deletion of multiple keys.
316 --delete-secret-key name
319 Remove key from the secret and public keyring. In batch mode the
320 key must be specified by fingerprint.
321 --delete-secret-and-public-key name
324 Same as --delete-key, but if a secret key exists, it will be
325 removed first. In batch mode the key must be specified by fin‐
326 gerprint.
327 --export
330 Either export all keys from all keyrings (default keyrings and
331 those registered via option --keyring), or if at least one name
332 is given, those of the given name. The new keyring is written to
333 STDOUT or to the file given with option --output. Use together
334 with --armor to mail those keys.
335 --send-keys key IDs
338 Similar to --export but sends the keys to a keyserver. Finger‐
339 prints may be used instead of key IDs. Option --keyserver must
340 be used to give the name of this keyserver. Don't send your com‐
341 plete keyring to a keyserver --- select only those keys which
342 are new or changed by you. If no key IDs are given, gpg does
343 nothing.
344 --export-secret-keys
347 --export-secret-subkeys
349 Same as --export, but exports the secret keys instead. This is
350 normally not very useful and a security risk. The second form
351 of the command has the special property to render the secret
352 part of the primary key useless; this is a GNU extension to
353 OpenPGP and other implementations can not be expected to suc‐
354 cessfully import such a key. See the option --simple-sk-check‐
355 sum if you want to import such an exported key with an older
356 OpenPGP implementation.
357 --import
360 --fast-import
362 Import/merge keys. This adds the given keys to the keyring. The
363 fast version is currently just a synonym.
364 There are a few other options which control how this command
366 works. Most notable here is the --import-options merge-only
367 option which does not insert new keys but does only the merging
368 of new signatures, user-IDs and subkeys.
369 --recv-keys key IDs
372 Import the keys with the given key IDs from a keyserver. Option
373 --keyserver must be used to give the name of this keyserver.
374 --refresh-keys
377 Request updates from a keyserver for keys that already exist on
378 the local keyring. This is useful for updating a key with the
379 latest signatures, user IDs, etc. Calling this with no arguments
380 will refresh the entire keyring. Option --keyserver must be used
381 to give the name of the keyserver for all keys that do not have
382 preferred keyservers set (see --keyserver-options honor-key‐
383 server-url).
384 --search-keys names
387 Search the keyserver for the given names. Multiple names given
388 here will be joined together to create the search string for the
389 keyserver. Option --keyserver must be used to give the name of
390 this keyserver. Keyservers that support different search meth‐
391 ods allow using the syntax specified in "How to specify a user
392 ID" below. Note that different keyserver types support different
393 search methods. Currently only LDAP supports them all.
394 --fetch-keys URIs
397 Retrieve keys located at the specified URIs. Note that different
398 installations of GnuPG may support different protocols (HTTP,
399 FTP, LDAP, etc.)
400 --update-trustdb
403 Do trust database maintenance. This command iterates over all
404 keys and builds the Web of Trust. This is an interactive command
405 because it may have to ask for the "ownertrust" values for keys.
406 The user has to give an estimation of how far she trusts the
407 owner of the displayed key to correctly certify (sign) other
408 keys. GnuPG only asks for the ownertrust value if it has not yet
409 been assigned to a key. Using the --edit-key menu, the assigned
410 value can be changed at any time.
411 --check-trustdb
414 Do trust database maintenance without user interaction. From
415 time to time the trust database must be updated so that expired
416 keys or signatures and the resulting changes in the Web of Trust
417 can be tracked. Normally, GnuPG will calculate when this is
418 required and do it automatically unless --no-auto-check-trustdb
419 is set. This command can be used to force a trust database check
420 at any time. The processing is identical to that of --update-
421 trustdb but it skips keys with a not yet defined "ownertrust".
422 For use with cron jobs, this command can be used together with
424 --batch in which case the trust database check is done only if a
425 check is needed. To force a run even in batch mode add the
426 option --yes.
427 --export-ownertrust
431 Send the ownertrust values to STDOUT. This is useful for backup
432 purposes as these values are the only ones which can't be re-
433 created from a corrupted trustdb. Example:
434 gpg --export-ownertrust > otrust.txt
435 --import-ownertrust
439 Update the trustdb with the ownertrust values stored in files
440 (or STDIN if not given); existing values will be overwritten.
441 In case of a severely damaged trustdb and if you have a recent
442 backup of the ownertrust values (e.g. in the file `otrust.txt',
443 you may re-create the trustdb using these commands:
444 cd ~/.gnupg
445 rm trustdb.gpg
446 gpg --import-ownertrust < otrust.txt
447 --rebuild-keydb-caches
451 When updating from version 1.0.6 to 1.0.7 this command should be
452 used to create signature caches in the keyring. It might be
453 handy in other situations too.
454 --print-md algo
457 --print-mds
459 Print message digest of algorithm ALGO for all given files or
460 STDIN. With the second form (or a deprecated "*" as algo)
461 digests for all available algorithms are printed.
462 --gen-random 0|1|2 count
465 Emit count random bytes of the given quality level 0, 1 or 2. If
466 count is not given or zero, an endless sequence of random bytes
467 will be emitted. If used with --armor the output will be base64
468 encoded. PLEASE, don't use this command unless you know what
469 you are doing; it may remove precious entropy from the system!
470 --gen-prime mode bits
473 Use the source, Luke :-). The output format is still subject to
474 change.
475 --enarmor
479 --dearmor
481 Pack or unpack an arbitrary input into/from an OpenPGP ASCII
482 armor. This is a GnuPG extension to OpenPGP and in general not
483 very useful.
484 How to manage your keys
490 This section explains the main commands for key management
493 --gen-key
497 Generate a new key pair. This command is normally only used
498 interactively.
499 There is an experimental feature which allows you to create keys
501 in batch mode. See the file `doc/DETAILS' in the source distri‐
502 bution on how to use this.
503 --gen-revoke name
506 Generate a revocation certificate for the complete key. To
507 revoke a subkey or a signature, use the --edit command.
508 --desig-revoke name
511 Generate a designated revocation certificate for a key. This
512 allows a user (with the permission of the keyholder) to revoke
513 someone else's key.
514 --edit-key
518 Present a menu which enables you to do most of the key manage‐
519 ment related tasks. It expects the specification of a key on
520 the command line.
521 uid n Toggle selection of user ID or photographic user ID with
525 index n. Use * to select all and 0 to deselect all.
526 key n Toggle selection of subkey with index n. Use * to select
529 all and 0 to deselect all.
530 sign Make a signature on key of user name If the key is not
533 yet signed by the default user (or the users given with
534 -u), the program displays the information of the key
535 again, together with its fingerprint and asks whether it
536 should be signed. This question is repeated for all users
537 specified with -u.
538 lsign Same as "sign" but the signature is marked as non-
541 exportable and will therefore never be used by others.
542 This may be used to make keys valid only in the local
543 environment.
544 nrsign Same as "sign" but the signature is marked as non-revoca‐
547 ble and can therefore never be revoked.
548 tsign Make a trust signature. This is a signature that combines
551 the notions of certification (like a regular signature),
552 and trust (like the "trust" command). It is generally
553 only useful in distinct communities or groups.
554 Note that "l" (for local / non-exportable), "nr" (for non-revo‐
556 cable, and "t" (for trust) may be freely mixed and prefixed to
557 "sign" to create a signature of any type desired.
558 delsig Delete a signature. Note that it is not possible to
562 retract a signature, once it has been send to the public
563 (i.e. to a keyserver). In that case you better use
564 revsig.
565 revsig Revoke a signature. For every signature which has been
568 generated by one of the secret keys, GnuPG asks whether a
569 revocation certificate should be generated.
570 check Check the signatures on all selected user IDs.
573 adduid Create an additional user ID.
576 addphoto
579 Create a photographic user ID. This will prompt for a
580 JPEG file that will be embedded into the user ID. Note
581 that a very large JPEG will make for a very large key.
582 Also note that some programs will display your JPEG
583 unchanged (GnuPG), and some programs will scale it to fit
584 in a dialog box (PGP).
585 showphoto
588 Display the selected photographic user ID.
589 deluid Delete a user ID or photographic user ID. Note that it
592 is not possible to retract a user id, once it has been
593 send to the public (i.e. to a keyserver). In that case
594 you better use revuid.
595 revuid Revoke a user ID or photographic user ID.
598 primary
601 Flag the current user id as the primary one, removes the
602 primary user id flag from all other user ids and sets the
603 timestamp of all affected self-signatures one second
604 ahead. Note that setting a photo user ID as primary makes
605 it primary over other photo user IDs, and setting a regu‐
606 lar user ID as primary makes it primary over other regu‐
607 lar user IDs.
608 keyserver
611 Set a preferred keyserver for the specified user ID(s).
612 This allows other users to know where you prefer they get
613 your key from. See --keyserver-options honor-keyserver-
614 url for more on how this works. Setting a value of
615 "none" removes an existing preferred keyserver.
616 notation
619 Set a name=value notation for the specified user ID(s).
620 See --cert-notation for more on how this works. Setting a
621 value of "none" removes all notations, setting a notation
622 prefixed with a minus sign (-) removes that notation, and
623 setting a notation name (without the =value) prefixed
624 with a minus sign removes all notations with that name.
625 pref List preferences from the selected user ID. This shows
628 the actual preferences, without including any implied
629 preferences.
630 showpref
633 More verbose preferences listing for the selected user
634 ID. This shows the preferences in effect by including the
635 implied preferences of 3DES (cipher), SHA-1 (digest), and
636 Uncompressed (compression) if they are not already
637 included in the preference list. In addition, the pre‐
638 ferred keyserver and signature notations (if any) are
639 shown.
640 setpref string
643 Set the list of user ID preferences to string for all (or
644 just the selected) user IDs. Calling setpref with no
645 arguments sets the preference list to the default (either
646 built-in or set via --default-preference-list), and call‐
647 ing setpref with "none" as the argument sets an empty
648 preference list. Use gpg --version to get a list of
649 available algorithms. Note that while you can change the
650 preferences on an attribute user ID (aka "photo ID"),
651 GnuPG does not select keys via attribute user IDs so
652 these preferences will not be used by GnuPG.
653 When setting preferences, you should list the algorithms
655 in the order which you'd like to see them used by someone
656 else when encrypting a message to your key. If you don't
657 include 3DES, it will be automatically added at the end.
658 Note that there are many factors that go into choosing an
659 algorithm (for example, your key may not be the only
660 recipient), and so the remote OpenPGP application being
661 used to send to you may or may not follow your exact cho‐
662 sen order for a given message. It will, however, only
663 choose an algorithm that is present on the preference
664 list of every recipient key. See also the INTEROPERABIL‐
665 ITY WITH OTHER OPENPGP PROGRAMS section below.
666 addkey Add a subkey to this key.
669 addcardkey
672 Generate a subkey on a card and add it to this key.
673 keytocard
676 Transfer the selected secret subkey (or the primary key
677 if no subkey has been selected) to a smartcard. The
678 secret key in the keyring will be replaced by a stub if
679 the key could be stored successfully on the card and you
680 use the save command later. Only certain key types may be
681 transferred to the card. A sub menu allows you to select
682 on what card to store the key. Note that it is not possi‐
683 ble to get that key back from the card - if the card gets
684 broken your secret key will be lost unless you have a
685 backup somewhere.
686 bkuptocard file
689 Restore the given file to a card. This command may be
690 used to restore a backup key (as generated during card
691 initialization) to a new card. In almost all cases this
692 will be the encryption key. You should use this command
693 only with the corresponding public key and make sure that
694 the file given as argument is indeed the backup to
695 restore. You should then select 2 to restore as encryp‐
696 tion key. You will first be asked to enter the
697 passphrase of the backup key and then for the Admin PIN
698 of the card.
699 delkey Remove a subkey (secondart key). Note that it is not pos‐
702 sible to retract a subkey, once it has been send to the
703 public (i.e. to a keyserver). In that case you better
704 use revkey.
705 revkey Revoke a subkey.
708 expire Change the key or subkey expiration time. If a subkey is
711 selected, the expiration time of this subkey will be
712 changed. With no selection, the key expiration of the
713 primary key is changed.
714 trust Change the owner trust value for the key. This updates
717 the trust-db immediately and no save is required.
718 disable
721 enable Disable or enable an entire key. A disabled key can not
723 normally be used for encryption.
724 addrevoker
727 Add a designated revoker to the key. This takes one
728 optional argument: "sensitive". If a designated revoker
729 is marked as sensitive, it will not be exported by
730 default (see export-options).
731 passwd Change the passphrase of the secret key.
734 toggle Toggle between public and secret key listing.
737 clean Compact (by removing all signatures except the selfsig)
740 any user ID that is no longer usable (e.g. revoked, or
741 expired). Then, remove any signatures that are not usable
742 by the trust calculations. Specifically, this removes
743 any signature that does not validate, any signature that
744 is superseded by a later signature, revoked signatures,
745 and signatures issued by keys that are not present on the
746 keyring.
747 minimize
750 Make the key as small as possible. This removes all sig‐
751 natures from each user ID except for the most recent
752 self-signature.
753 cross-certify
756 Add cross-certification signatures to signing subkeys
757 that may not currently have them. Cross-certification
758 signatures protect against a subtle attack against sign‐
759 ing subkeys. See --require-cross-certification. All new
760 keys generated have this signature by default, so this
761 option is only useful to bring older keys up to date.
762 save Save all changes to the key rings and quit.
765 quit Quit the program without updating the key rings.
768 The listing shows you the key with its secondary keys and all
771 user ids. The primary user id is indicated by a dot, and
772 selected keys or user ids are indicated by an asterisk. The
773 trust value is displayed with the primary key: the first is the
774 assigned owner trust and the second is the calculated trust
775 value. Letters are used for the values:
776 - No ownertrust assigned / not yet calculated.
780 e Trust calculation has failed; probably due to an expired
783 key.
784 q Not enough information for calculation.
787 n Never trust this key.
790 m Marginally trusted.
793 f Fully trusted.
796 u Ultimately trusted.
799 --sign-key name
802 Signs a public key with your secret key. This is a shortcut ver‐
803 sion of the subcommand "sign" from --edit.
804 --lsign-key name
807 Signs a public key with your secret key but marks it as non-
808 exportable. This is a shortcut version of the subcommand "lsign"
809 from --edit-key.
810
817 gpg features a bunch of options to control the exact behaviour and to
818 change the default configuration.
819 Long options can be put in an options file (default
822 "~/.gnupg/gpg.conf"). Short option names will not work - for example,
823 "armor" is a valid option for the options file, while "a" is not. Do
824 not write the 2 dashes, but simply the name of the option and any
825 required arguments. Lines with a hash ('#') as the first non-white-
826 space character are ignored. Commands may be put in this file too, but
827 that is not generally useful as the command will execute automatically
828 with every execution of gpg.
829 Please remember that option parsing stops as soon as a non-option is
831 encountered, you can explicitly stop parsing by using the special
832 option --.
833 How to change the configuration
837 These options are used to change the configuration and are usually
840 found in the option file.
841 --default-key name
845 Use name as the default key to sign with. If this option is not
846 used, the default key is the first key found in the secret
847 keyring. Note that -u or --local-user overrides this option.
848 --default-recipient name
851 Use name as default recipient if option --recipient is not used
852 and don't ask if this is a valid one. name must be non-empty.
853 --default-recipient-self
856 Use the default key as default recipient if option --recipient
857 is not used and don't ask if this is a valid one. The default
858 key is the first one from the secret keyring or the one set with
859 --default-key.
860 --no-default-recipient
863 Reset --default-recipient and --default-recipient-self.
864 -v, --verbose
867 Give more information during processing. If used twice, the
868 input data is listed in detail.
869 --no-verbose
872 Reset verbose level to 0.
873 -q, --quiet
876 Try to be as quiet as possible.
877 --batch
880 --no-batch
882 Use batch mode. Never ask, do not allow interactive commands.
883 --no-batch disables this option. Note that even with a filename
884 given on the command line, gpg might still need to read from
885 STDIN (in particular if gpg figures that the input is a detached
886 signature and no data file has been specified). Thus if you do
887 not want to feed data via STDIN, you should connect STDIN to
888 `/dev/null'.
889 --no-tty
892 Make sure that the TTY (terminal) is never used for any output.
893 This option is needed in some cases because GnuPG sometimes
894 prints warnings to the TTY even if --batch is used.
895 --yes Assume "yes" on most questions.
898 --no Assume "no" on most questions.
901 --list-options parameters
905 This is a space or comma delimited string that gives options
906 used when listing keys and signatures (that is, --list-keys,
907 --list-sigs, --list-public-keys, --list-secret-keys, and the
908 --edit-key functions). Options can be prepended with a no-
909 (after the two dashes) to give the opposite meaning. The
910 options are:
911 show-photos
915 Causes --list-keys, --list-sigs, --list-public-keys, and
916 --list-secret-keys to display any photo IDs attached to
917 the key. Defaults to no. See also --photo-viewer.
918 show-policy-urls
921 Show policy URLs in the --list-sigs or --check-sigs list‐
922 ings. Defaults to no.
923 show-notations
926 show-std-notations
928 show-user-notations
930 Show all, IETF standard, or user-defined signature nota‐
931 tions in the --list-sigs or --check-sigs listings.
932 Defaults to no.
933 show-keyserver-urls
936 Show any preferred keyserver URL in the --list-sigs or
938 --check-sigs listings. Defaults to no.
939 show-uid-validity
942 Display the calculated validity of user IDs during key
943 listings. Defaults to no.
944 show-unusable-uids
947 Show revoked and expired user IDs in key listings.
948 Defaults to no.
949 show-unusable-subkeys
952 Show revoked and expired subkeys in key listings.
953 Defaults to no.
954 show-keyring
957 Display the keyring name at the head of key listings to
958 show which keyring a given key resides on. Defaults to
959 no.
960 show-sig-expire
963 Show signature expiration dates (if any) during --list-
964 sigs or --check-sigs listings. Defaults to no.
965 show-sig-subpackets
968 Include signature subpackets in the key listing. This
969 option can take an optional argument list of the subpack‐
970 ets to list. If no argument is passed, list all subpack‐
971 ets. Defaults to no. This option is only meaningful when
972 using --with-colons along with --list-sigs or --check-
973 sigs.
974 --verify-options parameters
977 This is a space or comma delimited string that gives options
978 used when verifying signatures. Options can be prepended with a
979 `no-' to give the opposite meaning. The options are:
980 show-photos
984 Display any photo IDs present on the key that issued the
985 signature. Defaults to no. See also --photo-viewer.
986 show-policy-urls
989 Show policy URLs in the signature being verified.
990 Defaults to no.
991 show-notations
994 show-std-notations
996 show-user-notations
998 Show all, IETF standard, or user-defined signature nota‐
999 tions in the signature being verified. Defaults to IETF
1000 standard.
1001 show-keyserver-urls
1004 Show any preferred keyserver URL in the signature being
1005 verified. Defaults to no.
1006 show-uid-validity
1009 Display the calculated validity of the user IDs on the
1010 key that issued the signature. Defaults to no.
1011 show-unusable-uids
1014 Show revoked and expired user IDs during signature veri‐
1015 fication. Defaults to no.
1016 show-primary-uid-only
1019 Show only the primary user ID during signature verifica‐
1020 tion. That is all the AKA lines as well as photo Ids are
1021 not shown with the signature verification status.
1022 pka-lookups
1025 Enable PKA lookups to verify sender addresses. Note that
1026 PKA is based on DNS, and so enabling this option may dis‐
1027 close information on when and what signatures are veri‐
1028 fied or to whom data is encrypted. This is similar to the
1029 "web bug" described for the auto-key-retrieve feature.
1030 pka-trust-increase
1033 Raise the trust in a signature to full if the signature
1034 passes PKA validation. This option is only meaningful if
1035 pka-lookups is set.
1036 --enable-dsa2
1039 --disable-dsa2
1041 Enable hash truncation for all DSA keys even for old DSA Keys up
1042 to 1024 bit. This is also the default with --openpgp. Note
1043 that older versions of GnuPG also required this flag to allow
1044 the generation of DSA larger than 1024 bit.
1045 --photo-viewer string
1048 This is the command line that should be run to view a photo ID.
1049 "%i" will be expanded to a filename containing the photo. "%I"
1050 does the same, except the file will not be deleted once the
1051 viewer exits. Other flags are "%k" for the key ID, "%K" for the
1052 long key ID, "%f" for the key fingerprint, "%t" for the exten‐
1053 sion of the image type (e.g. "jpg"), "%T" for the MIME type of
1054 the image (e.g. "image/jpeg"), "%v" for the single-character
1055 calculated validity of the image being viewed (e.g. "f"), "%V"
1056 for the calculated validity as a string (e.g. "full"), and "%%"
1057 for an actual percent sign. If neither %i or %I are present,
1058 then the photo will be supplied to the viewer on standard input.
1059 The default viewer is "xloadimage -fork -quiet -title 'KeyID
1061 0x%k' STDIN". Note that if your image viewer program is not
1062 secure, then executing it from GnuPG does not make it secure.
1063 --exec-path string
1066 Sets a list of directories to search for photo viewers and key‐
1067 server helpers. If not provided, keyserver helpers use the com‐
1068 piled-in default directory, and photo viewers use the $PATH
1069 environment variable. Note, that on W32 system this value is
1070 ignored when searching for keyserver helpers.
1071 --keyring file
1074 Add file to the current list of keyrings. If file begins with a
1075 tilde and a slash, these are replaced by the $HOME directory. If
1076 the filename does not contain a slash, it is assumed to be in
1077 the GnuPG home directory ("~/.gnupg" if --homedir or $GNUPGHOME
1078 is not used).
1079 Note that this adds a keyring to the current list. If the intent
1081 is to use the specified keyring alone, use --keyring along with
1082 --no-default-keyring.
1083 --secret-keyring file
1086 Same as --keyring but for the secret keyrings.
1087 --primary-keyring file
1090 Designate file as the primary public keyring. This means that
1091 newly imported keys (via --import or keyserver --recv-from) will
1092 go to this keyring.
1093 --trustdb-name file
1096 Use file instead of the default trustdb. If file begins with a
1097 tilde and a slash, these are replaced by the $HOME directory. If
1098 the filename does not contain a slash, it is assumed to be in
1099 the GnuPG home directory (`~/.gnupg' if --homedir or $GNUPGHOME
1100 is not used).
1101 --homedir dir
1105 Set the name of the home directory to dir. If this option is not
1106 used, the home directory defaults to `~/.gnupg'. It is only
1107 recognized when given on the command line. It also overrides
1108 any home directory stated through the environment variable
1109 `GNUPGHOME' or (on W32 systems) by means of the Registry entry
1110 HKCU\Software\GNU\GnuPG:HomeDir.
1111 --pcsc-driver file
1116 Use file to access the smartcard reader. The current default is
1117 `libpcsclite.so.1' for GLIBC based systems, `/Sys‐
1118 tem/Library/Frameworks/PCSC.framework/PCSC' for MAC OS X, `win‐
1119 scard.dll' for Windows and `libpcsclite.so' for other systems.
1120 --disable-ccid
1123 Disable the integrated support for CCID compliant readers. This
1124 allows to fall back to one of the other drivers even if the
1125 internal CCID driver can handle the reader. Note, that CCID sup‐
1126 port is only available if libusb was available at build time.
1127 --reader-port number_or_string
1130 This option may be used to specify the port of the card termi‐
1131 nal. A value of 0 refers to the first serial device; add 32768
1132 to access USB devices. The default is 32768 (first USB device).
1133 PC/SC or CCID readers might need a string here; run the program
1134 in verbose mode to get a list of available readers. The default
1135 is then the first reader found.
1136 --display-charset name
1139 Set the name of the native character set. This is used to con‐
1140 vert some informational strings like user IDs to the proper
1141 UTF-8 encoding. Note that this has nothing to do with the char‐
1142 acter set of data to be encrypted or signed; GnuPG does not
1143 recode user-supplied data. If this option is not used, the
1144 default character set is determined from the current locale. A
1145 verbosity level of 3 shows the chosen set. Valid values for
1146 name are:
1147 iso-8859-1
1151 This is the Latin 1 set.
1152 iso-8859-2
1155 The Latin 2 set.
1156 iso-8859-15
1159 This is currently an alias for the Latin 1 set.
1160 koi8-r The usual Russian set (rfc1489).
1163 utf-8 Bypass all translations and assume that the OS uses
1166 native UTF-8 encoding.
1167 --utf8-strings
1170 --no-utf8-strings
1172 Assume that command line arguments are given as UTF8 strings.
1173 The default (--no-utf8-strings) is to assume that arguments are
1174 encoded in the character set as specified by --display-charset.
1175 These options affect all following arguments. Both options may
1176 be used multiple times.
1177 --options file
1181 Read options from file and do not try to read them from the
1182 default options file in the homedir (see --homedir). This option
1183 is ignored if used in an options file.
1184 --no-options
1187 Shortcut for --options /dev/null. This option is detected before
1188 an attempt to open an option file. Using this option will also
1189 prevent the creation of a `~/.gnupg' homedir.
1190 -z n
1195 --compress-level n
1197 --bzip2-compress-level n
1199 Set compression level to n for the ZIP and ZLIB compression
1200 algorithms. The default is to use the default compression level
1201 of zlib (normally 6). --bzip2-compress-level sets the compres‐
1202 sion level for the BZIP2 compression algorithm (defaulting to 6
1203 as well). This is a different option from --compress-level since
1204 BZIP2 uses a significant amount of memory for each additional
1205 compression level. -z sets both. A value of 0 for n disables
1206 compression.
1207 --bzip2-decompress-lowmem
1210 Use a different decompression method for BZIP2 compressed files.
1211 This alternate method uses a bit more than half the memory, but
1212 also runs at half the speed. This is useful under extreme low
1213 memory circumstances when the file was originally compressed at
1214 a high --bzip2-compress-level.
1215 --mangle-dos-filenames
1219 --no-mangle-dos-filenames
1221 Older version of Windows cannot handle filenames with more than
1222 one dot. --mangle-dos-filenames causes GnuPG to replace (rather
1223 than add to) the extension of an output filename to avoid this
1224 problem. This option is off by default and has no effect on non-
1225 Windows platforms.
1226 --ask-cert-level
1229 --no-ask-cert-level
1231 When making a key signature, prompt for a certification level.
1232 If this option is not specified, the certification level used is
1233 set via --default-cert-level. See --default-cert-level for
1234 information on the specific levels and how they are used. --no-
1235 ask-cert-level disables this option. This option defaults to no.
1236 --default-cert-level n
1239 The default to use for the check level when signing a key.
1240 0 means you make no particular claim as to how carefully you
1242 verified the key.
1243 1 means you believe the key is owned by the person who claims to
1245 own it but you could not, or did not verify the key at all. This
1246 is useful for a "persona" verification, where you sign the key
1247 of a pseudonymous user.
1248 2 means you did casual verification of the key. For example,
1250 this could mean that you verified that the key fingerprint and
1251 checked the user ID on the key against a photo ID.
1252 3 means you did extensive verification of the key. For example,
1254 this could mean that you verified the key fingerprint with the
1255 owner of the key in person, and that you checked, by means of a
1256 hard to forge document with a photo ID (such as a passport) that
1257 the name of the key owner matches the name in the user ID on the
1258 key, and finally that you verified (by exchange of email) that
1259 the email address on the key belongs to the key owner.
1260 Note that the examples given above for levels 2 and 3 are just
1262 that: examples. In the end, it is up to you to decide just what
1263 "casual" and "extensive" mean to you.
1264 This option defaults to 0 (no particular claim).
1266 --min-cert-level
1269 When building the trust database, treat any signatures with a
1270 certification level below this as invalid. Defaults to 2, which
1271 disregards level 1 signatures. Note that level 0 "no particular
1272 claim" signatures are always accepted.
1273 --trusted-key long key ID
1276 Assume that the specified key (which must be given as a full 8
1277 byte key ID) is as trustworthy as one of your own secret keys.
1278 This option is useful if you don't want to keep your secret keys
1279 (or one of them) online but still want to be able to check the
1280 validity of a given recipient's or signator's key.
1281 --trust-model pgp|classic|direct|always|auto
1284 Set what trust model GnuPG should follow. The models are:
1285 pgp This is the Web of Trust combined with trust signatures
1289 as used in PGP 5.x and later. This is the default trust
1290 model when creating a new trust database.
1291 classic
1294 This is the standard Web of Trust as used in PGP 2.x and
1295 earlier.
1296 direct Key validity is set directly by the user and not calcu‐
1299 lated via the Web of Trust.
1300 always Skip key validation and assume that used keys are always
1303 fully trusted. You generally won't use this unless you
1304 are using some external validation scheme. This option
1305 also suppresses the "[uncertain]" tag printed with signa‐
1306 ture checks when there is no evidence that the user ID is
1307 bound to the key.
1308 auto Select the trust model depending on whatever the internal
1311 trust database says. This is the default model if such a
1312 database already exists.
1313 --auto-key-locate parameters
1316 --no-auto-key-locate
1318 GnuPG can automatically locate and retrieve keys as needed using
1319 this option. This happens when encrypting to an email address
1320 (in the "user@example.com" form), and there are no user@exam‐
1321 ple.com keys on the local keyring. This option takes any number
1322 of the following mechanisms, in the order they are to be tried:
1323 cert Locate a key using DNS CERT, as specified in rfc4398.
1327 pka Locate a key using DNS PKA.
1330 ldap Using DNS Service Discovery, check the domain in question
1333 for any LDAP keyservers to use. If this fails, attempt
1334 to locate the key using the PGP Universal method of
1335 checking 'ldap://keys.(thedomain)''.
1336 keyserver
1339 Locate a key using whatever keyserver is defined using
1340 the --keyserver option.
1341 keyserver-URL
1344 In addition, a keyserver URL as used in the --keyserver
1345 option may be used here to query that particular key‐
1346 server.
1347 local Locate the key using the local keyrings. This mechanism
1350 allows to select the order a local key lookup is done.
1351 Thus using '--auto-key-locate local'' is identical to
1352 --no-auto-key-locate.
1353 nodefault
1356 This flag disables the standard local key lookup, done
1357 before any of the mechanisms defined by the --auto-key-
1358 locate are tried. The position of this mechanism in the
1359 list does not matter. It is not required if local is
1360 also used.
1361 --keyid-format short|0xshort|long|0xlong
1365 Select how to display key IDs. "short" is the traditional
1366 8-character key ID. "long" is the more accurate (but less conve‐
1367 nient) 16-character key ID. Add an "0x" to either to include an
1368 "0x" at the beginning of the key ID, as in 0x99242560.
1369 --keyserver name
1372 Use name as your keyserver. This is the server that --recv-keys,
1373 --send-keys, and --search-keys will communicate with to receive
1374 keys from, send keys to, and search for keys on. The format of
1375 the name is a URI: `scheme:[//]keyservername[:port]' The scheme
1376 is the type of keyserver: "hkp" for the HTTP (or compatible)
1377 keyservers, "ldap" for the LDAP keyservers, or "mailto" for the
1378 Graff email keyserver. Note that your particular installation of
1379 GnuPG may have other keyserver types available as well. Key‐
1380 server schemes are case-insensitive. After the keyserver name,
1381 optional keyserver configuration options may be provided. These
1382 are the same as the global --keyserver-options from below, but
1383 apply only to this particular keyserver.
1384 Most keyservers synchronize with each other, so there is gener‐
1386 ally no need to send keys to more than one server. The keyserver
1387 hkp://keys.gnupg.net uses round robin DNS to give a different
1388 keyserver each time you use it.
1389 --keyserver-options name=value1
1392 This is a space or comma delimited string that gives options for
1393 the keyserver. Options can be prefixed with a `no-' to give the
1394 opposite meaning. Valid import-options or export-options may be
1395 used here as well to apply to importing (--recv-key) or export‐
1396 ing (--send-key) a key from a keyserver. While not all options
1397 are available for all keyserver types, some common options are:
1398 include-revoked
1402 When searching for a key with --search-keys, include keys
1403 that are marked on the keyserver as revoked. Note that
1404 not all keyservers differentiate between revoked and
1405 unrevoked keys, and for such keyservers this option is
1406 meaningless. Note also that most keyservers do not have
1407 cryptographic verification of key revocations, and so
1408 turning this option off may result in skipping keys that
1409 are incorrectly marked as revoked.
1410 include-disabled
1413 When searching for a key with --search-keys, include keys
1414 that are marked on the keyserver as disabled. Note that
1415 this option is not used with HKP keyservers.
1416 auto-key-retrieve
1419 This option enables the automatic retrieving of keys from
1420 a keyserver when verifying signatures made by keys that
1421 are not on the local keyring.
1422 Note that this option makes a "web bug" like behavior
1424 possible. Keyserver operators can see which keys you
1425 request, so by sending you a message signed by a brand
1426 new key (which you naturally will not have on your local
1427 keyring), the operator can tell both your IP address and
1428 the time when you verified the signature.
1429 honor-keyserver-url
1432 When using --refresh-keys, if the key in question has a
1433 preferred keyserver URL, then use that preferred key‐
1434 server to refresh the key from. In addition, if auto-key-
1435 retrieve is set, and the signature being verified has a
1436 preferred keyserver URL, then use that preferred key‐
1437 server to fetch the key from. Defaults to yes.
1438 honor-pka-record
1441 If auto-key-retrieve is set, and the signature being ver‐
1442 ified has a PKA record, then use the PKA information to
1443 fetch the key. Defaults to yes.
1444 include-subkeys
1447 When receiving a key, include subkeys as potential tar‐
1448 gets. Note that this option is not used with HKP key‐
1449 servers, as they do not support retrieving keys by subkey
1450 id.
1451 use-temp-files
1454 On most Unix-like platforms, GnuPG communicates with the
1455 keyserver helper program via pipes, which is the most
1456 efficient method. This option forces GnuPG to use tempo‐
1457 rary files to communicate. On some platforms (such as
1458 Win32 and RISC OS), this option is always enabled.
1459 keep-temp-files
1462 If using `use-temp-files', do not delete the temp files
1463 after using them. This option is useful to learn the key‐
1464 server communication protocol by reading the temporary
1465 files.
1466 verbose
1469 Tell the keyserver helper program to be more verbose.
1470 This option can be repeated multiple times to increase
1471 the verbosity level.
1472 timeout
1475 Tell the keyserver helper program how long (in seconds)
1476 to try and perform a keyserver action before giving up.
1477 Note that performing multiple actions at the same time
1478 uses this timeout value per action. For example, when
1479 retrieving multiple keys via --recv-keys, the timeout
1480 applies separately to each key retrieval, and not to the
1481 --recv-keys command as a whole. Defaults to 30 seconds.
1482 http-proxy=value
1485 Set the proxy to use for HTTP and HKP keyservers. This
1486 overrides the "http_proxy" environment variable, if any.
1487 max-cert-size
1490 When retrieving a key via DNS CERT, only accept keys up
1491 to this size. Defaults to 16384 bytes.
1492 debug Turn on debug output in the keyserver helper program.
1495 Note that the details of debug output depends on which
1496 keyserver helper program is being used, and in turn, on
1497 any libraries that the keyserver helper program uses
1498 internally (libcurl, openldap, etc).
1499 check-cert
1502 Enable certificate checking if the keyserver presents one
1503 (for hkps or ldaps). Defaults to on.
1504 ca-cert-file
1507 Provide a certificate store to override the system
1508 default. Only necessary if check-cert is enabled, and
1509 the keyserver is using a certificate that is not present
1510 in a system default certificate list.
1511 Note that depending on the SSL library that the keyserver
1513 helper is built with, this may actually be a directory or
1514 a file.
1515 --completes-needed n
1518 Number of completely trusted users to introduce a new key signer
1519 (defaults to 1).
1520 --marginals-needed n
1523 Number of marginally trusted users to introduce a new key signer
1524 (defaults to 3)
1525 --max-cert-depth n
1528 Maximum depth of a certification chain (default is 5).
1529 --simple-sk-checksum
1532 Secret keys are integrity protected by using a SHA-1 checksum.
1533 This method is part of the upcoming enhanced OpenPGP specifica‐
1534 tion but GnuPG already uses it as a countermeasure against cer‐
1535 tain attacks. Old applications don't understand this new for‐
1536 mat, so this option may be used to switch back to the old behav‐
1537 iour. Using this option bears a security risk. Note that using
1538 this option only takes effect when the secret key is encrypted -
1539 the simplest way to make this happen is to change the passphrase
1540 on the key (even changing it to the same value is acceptable).
1541 --no-sig-cache
1544 Do not cache the verification status of key signatures. Caching
1545 gives a much better performance in key listings. However, if you
1546 suspect that your public keyring is not save against write modi‐
1547 fications, you can use this option to disable the caching. It
1548 probably does not make sense to disable it because all kind of
1549 damage can be done if someone else has write access to your pub‐
1550 lic keyring.
1551 --no-sig-create-check
1554 GnuPG normally verifies each signature right after creation to
1555 protect against bugs and hardware malfunctions which could leak
1556 out bits from the secret key. This extra verification needs some
1557 time (about 115% for DSA keys), and so this option can be used
1558 to disable it. However, due to the fact that the signature cre‐
1559 ation needs manual interaction, this performance penalty does
1560 not matter in most settings.
1561 --auto-check-trustdb
1564 --no-auto-check-trustdb
1566 If GnuPG feels that its information about the Web of Trust has
1567 to be updated, it automatically runs the --check-trustdb command
1568 internally. This may be a time consuming process. --no-auto-
1569 check-trustdb disables this option.
1570 --use-agent
1573 --no-use-agent
1575 Try to use the GnuPG-Agent. With this option, GnuPG first tries
1576 to connect to the agent before it asks for a passphrase. --no-
1577 use-agent disables this option.
1578 --gpg-agent-info
1581 Override the value of the environment variable
1582 'GPG_AGENT_INFO''. This is only used when --use-agent has been
1583 given. Given that this option is not anymore used by gpg2, it
1584 should be avoided if possible.
1585 --lock-once
1588 Lock the databases the first time a lock is requested and do not
1589 release the lock until the process terminates.
1590 --lock-multiple
1593 Release the locks every time a lock is no longer needed. Use
1594 this to override a previous --lock-once from a config file.
1595 --lock-never
1598 Disable locking entirely. This option should be used only in
1599 very special environments, where it can be assured that only one
1600 process is accessing those files. A bootable floppy with a
1601 stand-alone encryption system will probably use this. Improper
1602 usage of this option may lead to data and key corruption.
1603 --exit-on-status-write-error
1606 This option will cause write errors on the status FD to immedi‐
1607 ately terminate the process. That should in fact be the default
1608 but it never worked this way and thus we need an option to
1609 enable this, so that the change won't break applications which
1610 close their end of a status fd connected pipe too early. Using
1611 this option along with --enable-progress-filter may be used to
1612 cleanly cancel long running gpg operations.
1613 --limit-card-insert-tries n
1616 With n greater than 0 the number of prompts asking to insert a
1617 smartcard gets limited to N-1. Thus with a value of 1 gpg won't
1618 at all ask to insert a card if none has been inserted at
1619 startup. This option is useful in the configuration file in case
1620 an application does not know about the smartcard support and
1621 waits ad infinitum for an inserted card.
1622 --no-random-seed-file
1625 GnuPG uses a file to store its internal random pool over invoca‐
1626 tions. This makes random generation faster; however sometimes
1627 write operations are not desired. This option can be used to
1628 achieve that with the cost of slower random generation.
1629 --no-greeting
1632 Suppress the initial copyright message.
1633 --no-secmem-warning
1636 Suppress the warning about "using insecure memory".
1637 --no-permission-warning
1640 Suppress the warning about unsafe file and home directory
1641 (--homedir) permissions. Note that the permission checks that
1642 GnuPG performs are not intended to be authoritative, but rather
1643 they simply warn about certain common permission problems. Do
1644 not assume that the lack of a warning means that your system is
1645 secure.
1646 Note that the warning for unsafe --homedir permissions cannot be
1648 suppressed in the gpg.conf file, as this would allow an attacker
1649 to place an unsafe gpg.conf file in place, and use this file to
1650 suppress warnings about itself. The --homedir permissions warn‐
1651 ing may only be suppressed on the command line.
1652 --no-mdc-warning
1655 Suppress the warning about missing MDC integrity protection.
1656 --require-secmem
1659 --no-require-secmem
1661 Refuse to run if GnuPG cannot get secure memory. Defaults to no
1662 (i.e. run, but give a warning).
1663 --require-cross-certification
1667 --no-require-cross-certification
1669 When verifying a signature made from a subkey, ensure that the
1670 cross certification "back signature" on the subkey is present
1671 and valid. This protects against a subtle attack against sub‐
1672 keys that can sign. Defaults to --require-cross-certification
1673 for gpg.
1674 --expert
1677 --no-expert
1679 Allow the user to do certain nonsensical or "silly" things like
1680 signing an expired or revoked key, or certain potentially incom‐
1681 patible things like generating unusual key types. This also dis‐
1682 ables certain warning messages about potentially incompatible
1683 actions. As the name implies, this option is for experts only.
1684 If you don't fully understand the implications of what it allows
1685 you to do, leave this off. --no-expert disables this option.
1686 Key related options
1695 --recipient name
1700 -r Encrypt for user id name. If this option or --hidden-recipient
1702 is not specified, GnuPG asks for the user-id unless --default-
1703 recipient is given.
1704 --hidden-recipient name
1707 -R Encrypt for user ID name, but hide the key ID of this user's
1709 key. This option helps to hide the receiver of the message and
1710 is a limited countermeasure against traffic analysis. If this
1711 option or --recipient is not specified, GnuPG asks for the user
1712 ID unless --default-recipient is given.
1713 --encrypt-to name
1716 Same as --recipient but this one is intended for use in the
1717 options file and may be used with your own user-id as an
1718 "encrypt-to-self". These keys are only used when there are other
1719 recipients given either by use of --recipient or by the asked
1720 user id. No trust checking is performed for these user ids and
1721 even disabled keys can be used.
1722 --hidden-encrypt-to name
1725 Same as --hidden-recipient but this one is intended for use in
1726 the options file and may be used with your own user-id as a hid‐
1727 den "encrypt-to-self". These keys are only used when there are
1728 other recipients given either by use of --recipient or by the
1729 asked user id. No trust checking is performed for these user
1730 ids and even disabled keys can be used.
1731 --no-encrypt-to
1734 Disable the use of all --encrypt-to and --hidden-encrypt-to
1735 keys.
1736 --group name=value1
1739 Sets up a named group, which is similar to aliases in email pro‐
1740 grams. Any time the group name is a recipient (-r or --recipi‐
1741 ent), it will be expanded to the values specified. Multiple
1742 groups with the same name are automatically merged into a single
1743 group.
1744 The values are key IDs or fingerprints, but any key description
1746 is accepted. Note that a value with spaces in it will be treated
1747 as two different values. Note also there is only one level of
1748 expansion --- you cannot make an group that points to another
1749 group. When used from the command line, it may be necessary to
1750 quote the argument to this option to prevent the shell from
1751 treating it as multiple arguments.
1752 --ungroup name
1755 Remove a given entry from the --group list.
1756 --no-groups
1759 Remove all entries from the --group list.
1760 --local-user name
1763 -u Use name as the key to sign with. Note that this option over‐
1765 rides --default-key.
1766 --try-secret-key name
1769 For hidden recipients GPG needs to know the keys to use for
1770 trial decryption. The key set with --default-key is always
1771 tried first, but this is often not sufficient. This option
1772 allows to set more keys to be used for trial decryption.
1773 Although any valid user-id specification may be used for name it
1774 makes sense to use at least the long keyid to avoid ambiguities.
1775 Note that gpg-agent might pop up a pinentry for a lot keys to do
1776 the trial decryption. If you want to stop all further trial
1777 decryption you may use close-window button instead of the cancel
1778 button.
1779 --try-all-secrets
1782 Don't look at the key ID as stored in the message but try all
1783 secret keys in turn to find the right decryption key. This
1784 option forces the behaviour as used by anonymous recipients
1785 (created by using --throw-keyids or --hidden-recipient) and
1786 might come handy in case where an encrypted message contains a
1787 bogus key ID.
1788 --skip-hidden-recipients
1791 --no-skip-hidden-recipients
1793 During decryption skip all anonymous recipients. This option
1794 helps in the case that people use the hidden recipients feature
1795 to hide there own encrypt-to key from others. If oneself has
1796 many secret keys this may lead to a major annoyance because all
1797 keys are tried in turn to decrypt soemthing which was not really
1798 intended for it. The drawback of this option is that it is cur‐
1799 rently not possible to decrypt a message which includes real
1800 anonymous recipients.
1801 Input and Output
1807 --armor
1812 -a Create ASCII armored output. The default is to create the
1814 binary OpenPGP format.
1815 --no-armor
1818 Assume the input data is not in ASCII armored format.
1819 --output file
1822 -o file
1824 Write output to file.
1825 --max-output n
1828 This option sets a limit on the number of bytes that will be
1829 generated when processing a file. Since OpenPGP supports various
1830 levels of compression, it is possible that the plaintext of a
1831 given message may be significantly larger than the original
1832 OpenPGP message. While GnuPG works properly with such messages,
1833 there is often a desire to set a maximum file size that will be
1834 generated before processing is forced to stop by the OS limits.
1835 Defaults to 0, which means "no limit".
1836 --import-options parameters
1839 This is a space or comma delimited string that gives options for
1840 importing keys. Options can be prepended with a `no-' to give
1841 the opposite meaning. The options are:
1842 import-local-sigs
1846 Allow importing key signatures marked as "local". This is
1847 not generally useful unless a shared keyring scheme is
1848 being used. Defaults to no.
1849 repair-pks-subkey-bug
1852 During import, attempt to repair the damage caused by the
1853 PKS keyserver bug (pre version 0.9.6) that mangles keys
1854 with multiple subkeys. Note that this cannot completely
1855 repair the damaged key as some crucial data is removed by
1856 the keyserver, but it does at least give you back one
1857 subkey. Defaults to no for regular --import and to yes
1858 for keyserver --recv-keys.
1859 merge-only
1862 During import, allow key updates to existing keys, but do
1863 not allow any new keys to be imported. Defaults to no.
1864 import-clean
1867 After import, compact (remove all signatures except the
1868 self-signature) any user IDs from the new key that are
1869 not usable. Then, remove any signatures from the new key
1870 that are not usable. This includes signatures that were
1871 issued by keys that are not present on the keyring. This
1872 option is the same as running the --edit-key command
1873 "clean" after import. Defaults to no.
1874 import-minimal
1877 Import the smallest key possible. This removes all signa‐
1878 tures except the most recent self-signature on each user
1879 ID. This option is the same as running the --edit-key
1880 command "minimize" after import. Defaults to no.
1881 --export-options parameters
1884 This is a space or comma delimited string that gives options for
1885 exporting keys. Options can be prepended with a `no-' to give
1886 the opposite meaning. The options are:
1887 export-local-sigs
1891 Allow exporting key signatures marked as "local". This is
1892 not generally useful unless a shared keyring scheme is
1893 being used. Defaults to no.
1894 export-attributes
1897 Include attribute user IDs (photo IDs) while exporting.
1898 This is useful to export keys if they are going to be
1899 used by an OpenPGP program that does not accept attribute
1900 user IDs. Defaults to yes.
1901 export-sensitive-revkeys
1904 Include designated revoker information that was marked as
1905 "sensitive". Defaults to no.
1906 export-reset-subkey-passwd
1909 When using the --export-secret-subkeys command, this
1910 option resets the passphrases for all exported subkeys to
1911 empty. This is useful when the exported subkey is to be
1912 used on an unattended machine where a passphrase doesn't
1913 necessarily make sense. Defaults to no.
1914 export-clean
1917 Compact (remove all signatures from) user IDs on the key
1918 being exported if the user IDs are not usable. Also, do
1919 not export any signatures that are not usable. This
1920 includes signatures that were issued by keys that are not
1921 present on the keyring. This option is the same as run‐
1922 ning the --edit-key command "clean" before export except
1923 that the local copy of the key is not modified. Defaults
1924 to no.
1925 export-minimal
1928 Export the smallest key possible. This removes all signa‐
1929 tures except the most recent self-signature on each user
1930 ID. This option is the same as running the --edit-key
1931 command "minimize" before export except that the local
1932 copy of the key is not modified. Defaults to no.
1933 --with-colons
1936 Print key listings delimited by colons. Note that the output
1937 will be encoded in UTF-8 regardless of any --display-charset
1938 setting. This format is useful when GnuPG is called from scripts
1939 and other programs as it is easily machine parsed. The details
1940 of this format are documented in the file `doc/DETAILS', which
1941 is included in the GnuPG source distribution.
1942 --fixed-list-mode
1945 Do not merge primary user ID and primary key in --with-colon
1946 listing mode and print all timestamps as seconds since
1947 1970-01-01.
1948 --with-fingerprint
1951 Same as the command --fingerprint but changes only the format of
1952 the output and may be used together with another command.
1953 --with-keygrip
1956 Include the keygrip in the key listings.
1957 OpenPGP protocol specific options.
1962 -t, --textmode
1967 --no-textmode
1969 Treat input files as text and store them in the OpenPGP canoni‐
1970 cal text form with standard "CRLF" line endings. This also sets
1971 the necessary flags to inform the recipient that the encrypted
1972 or signed data is text and may need its line endings converted
1973 back to whatever the local system uses. This option is useful
1974 when communicating between two platforms that have different
1975 line ending conventions (UNIX-like to Mac, Mac to Windows, etc).
1976 --no-textmode disables this option, and is the default.
1977 If -t (but not --textmode) is used together with armoring and
1979 signing, this enables clearsigned messages. This kludge is
1980 needed for command-line compatibility with command-line versions
1981 of PGP; normally you would use --sign or --clearsign to select
1982 the type of the signature.
1983 --force-v3-sigs
1986 --no-force-v3-sigs
1988 OpenPGP states that an implementation should generate v4 signa‐
1989 tures but PGP versions 5 through 7 only recognize v4 signatures
1990 on key material. This option forces v3 signatures for signatures
1991 on data. Note that this option implies --no-ask-sig-expire, and
1992 unsets --sig-policy-url, --sig-notation, and --sig-keyserver-
1993 url, as these features cannot be used with v3 signatures. --no-
1994 force-v3-sigs disables this option. Defaults to no.
1995 --force-v4-certs
1998 --no-force-v4-certs
2000 Always use v4 key signatures even on v3 keys. This option also
2001 changes the default hash algorithm for v3 RSA keys from MD5 to
2002 SHA-1. --no-force-v4-certs disables this option.
2003 --force-mdc
2006 Force the use of encryption with a modification detection code.
2007 This is always used with the newer ciphers (those with a block‐
2008 size greater than 64 bits), or if all of the recipient keys
2009 indicate MDC support in their feature flags.
2010 --disable-mdc
2013 Disable the use of the modification detection code. Note that by
2014 using this option, the encrypted message becomes vulnerable to a
2015 message modification attack.
2016 --personal-cipher-preferences string
2019 Set the list of personal cipher preferences to string. Use gpg
2020 --version to get a list of available algorithms, and use none to
2021 set no preference at all. This allows the user to safely over‐
2022 ride the algorithm chosen by the recipient key preferences, as
2023 GPG will only select an algorithm that is usable by all recipi‐
2024 ents. The most highly ranked cipher in this list is also used
2025 for the --symmetric encryption command.
2026 --personal-digest-preferences string
2029 Set the list of personal digest preferences to string. Use gpg
2030 --version to get a list of available algorithms, and use none to
2031 set no preference at all. This allows the user to safely over‐
2032 ride the algorithm chosen by the recipient key preferences, as
2033 GPG will only select an algorithm that is usable by all recipi‐
2034 ents. The most highly ranked digest algorithm in this list is
2035 also used when signing without encryption (e.g. --clearsign or
2036 --sign). The default value is SHA-1.
2037 --personal-compress-preferences string
2040 Set the list of personal compression preferences to string. Use
2041 gpg --version to get a list of available algorithms, and use
2042 none to set no preference at all. This allows the user to
2043 safely override the algorithm chosen by the recipient key pref‐
2044 erences, as GPG will only select an algorithm that is usable by
2045 all recipients. The most highly ranked compression algorithm in
2046 this list is also used when there are no recipient keys to con‐
2047 sider (e.g. --symmetric).
2048 --s2k-cipher-algo name
2051 Use name as the cipher algorithm used to protect secret keys.
2052 The default cipher is CAST5. This cipher is also used for con‐
2053 ventional encryption if --personal-cipher-preferences and
2054 --cipher-algo is not given.
2055 --s2k-digest-algo name
2058 Use name as the digest algorithm used to mangle the passphrases.
2059 The default algorithm is SHA-1.
2060 --s2k-mode n
2063 Selects how passphrases are mangled. If n is 0 a plain
2064 passphrase (which is not recommended) will be used, a 1 adds a
2065 salt to the passphrase and a 3 (the default) iterates the whole
2066 process a number of times (see --s2k-count). Unless --rfc1991
2067 is used, this mode is also used for conventional encryption.
2068 --s2k-count n
2071 Specify how many times the passphrase mangling is repeated.
2072 This value may range between 1024 and 65011712 inclusive, and
2073 the default is 65536. Note that not all values in the
2074 1024-65011712 range are legal and if an illegal value is
2075 selected, GnuPG will round up to the nearest legal value. This
2076 option is only meaningful if --s2k-mode is 3.
2077 Compliance options
2083 These options control what GnuPG is compliant to. Only one of these
2086 options may be active at a time. Note that the default setting of this
2087 is nearly always the correct one. See the INTEROPERABILITY WITH OTHER
2088 OPENPGP PROGRAMS section below before using one of these options.
2089 --gnupg
2093 Use standard GnuPG behavior. This is essentially OpenPGP behav‐
2094 ior (see --openpgp), but with some additional workarounds for
2095 common compatibility problems in different versions of PGP. This
2096 is the default option, so it is not generally needed, but it may
2097 be useful to override a different compliance option in the
2098 gpg.conf file.
2099 --openpgp
2102 Reset all packet, cipher and digest options to strict OpenPGP
2103 behavior. Use this option to reset all previous options like
2104 --s2k-*, --cipher-algo, --digest-algo and --compress-algo to
2105 OpenPGP compliant values. All PGP workarounds are disabled.
2106 --rfc4880
2109 Reset all packet, cipher and digest options to strict RFC-4880
2110 behavior. Note that this is currently the same thing as
2111 --openpgp.
2112 --rfc2440
2115 Reset all packet, cipher and digest options to strict RFC-2440
2116 behavior.
2117 --rfc1991
2120 Try to be more RFC-1991 (PGP 2.x) compliant.
2121 --pgp2 Set up all options to be as PGP 2.x compliant as possible, and
2124 warn if an action is taken (e.g. encrypting to a non-RSA key)
2125 that will create a message that PGP 2.x will not be able to han‐
2126 dle. Note that `PGP 2.x' here means `MIT PGP 2.6.2'. There are
2127 other versions of PGP 2.x available, but the MIT release is a
2128 good common baseline.
2129 This option implies --rfc1991 --disable-mdc --no-force-v4-certs
2131 --escape-from-lines --force-v3-sigs --cipher-algo IDEA --digest-
2132 algo MD5 --compress-algo ZIP. It also disables --textmode when
2133 encrypting.
2134 --pgp6 Set up all options to be as PGP 6 compliant as possible. This
2137 restricts you to the ciphers IDEA (if the IDEA plugin is
2138 installed), 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160,
2139 and the compression algorithms none and ZIP. This also disables
2140 --throw-keyids, and making signatures with signing subkeys as
2141 PGP 6 does not understand signatures made by signing subkeys.
2142 This option implies --disable-mdc --escape-from-lines --force-
2144 v3-sigs.
2145 --pgp7 Set up all options to be as PGP 7 compliant as possible. This is
2148 identical to --pgp6 except that MDCs are not disabled, and the
2149 list of allowable ciphers is expanded to add AES128, AES192,
2150 AES256, and TWOFISH.
2151 --pgp8 Set up all options to be as PGP 8 compliant as possible. PGP 8
2154 is a lot closer to the OpenPGP standard than previous versions
2155 of PGP, so all this does is disable --throw-keyids and set
2156 --escape-from-lines. All algorithms are allowed except for the
2157 SHA224, SHA384, and SHA512 digests.
2158 Doing things one usually doesn't want to do.
2164 -n
2169 --dry-run
2171 Don't make any changes (this is not completely implemented).
2172 --list-only
2175 Changes the behaviour of some commands. This is like --dry-run
2176 but different in some cases. The semantic of this command may be
2177 extended in the future. Currently it only skips the actual
2178 decryption pass and therefore enables a fast listing of the
2179 encryption keys.
2180 -i
2183 --interactive
2185 Prompt before overwriting any files.
2186 --debug-level level
2189 Select the debug level for investigating problems. level may be
2190 a numeric value or by a keyword:
2191 none No debugging at all. A value of less than 1 may be used
2194 instead of the keyword.
2195 basic Some basic debug messages. A value between 1 and 2 may
2197 be used instead of the keyword.
2198 advanced
2200 More verbose debug messages. A value between 3 and 5 may
2201 be used instead of the keyword.
2202 expert Even more detailed messages. A value between 6 and 8 may
2204 be used instead of the keyword.
2205 guru All of the debug messages you can get. A value greater
2207 than 8 may be used instead of the keyword. The creation
2208 of hash tracing files is only enabled if the keyword is
2209 used.
2210 How these messages are mapped to the actual debugging flags is not
2212 specified and may change with newer releases of this program. They are
2213 however carefully selected to best aid in debugging.
2214 --debug flags
2217 Set debugging flags. All flags are or-ed and flags may be given
2218 in C syntax (e.g. 0x0042).
2219 --debug-all
2222 Set all useful debugging flags.
2223 --debug-ccid-driver
2226 Enable debug output from the included CCID driver for smart‐
2227 cards. Note that this option is only available on some system.
2228 --faked-system-time epoch
2231 This option is only useful for testing; it sets the system time
2232 back or forth to epoch which is the number of seconds elapsed
2233 since the year 1970. Alternatively epoch may be given as a full
2234 ISO time string (e.g. "20070924T154812").
2235 --enable-progress-filter
2238 Enable certain PROGRESS status outputs. This option allows fron‐
2239 tends to display a progress indicator while gpg is processing
2240 larger files. There is a slight performance overhead using it.
2241 --status-fd n
2244 Write special status strings to the file descriptor n. See the
2245 file DETAILS in the documentation for a listing of them.
2246 --status-file file
2249 Same as --status-fd, except the status data is written to file
2250 file.
2251 --logger-fd n
2254 Write log output to file descriptor n and not to STDERR.
2255 --log-file file
2258 --logger-file file
2260 Same as --logger-fd, except the logger data is written to file
2261 file. Note that --log-file is only implemented for GnuPG-2.
2262 --attribute-fd n
2265 Write attribute subpackets to the file descriptor n. This is
2266 most useful for use with --status-fd, since the status messages
2267 are needed to separate out the various subpackets from the
2268 stream delivered to the file descriptor.
2269 --attribute-file file
2272 Same as --attribute-fd, except the attribute data is written to
2273 file file.
2274 --comment string
2277 --no-comments
2279 Use string as a comment string in clear text signatures and
2280 ASCII armored messages or keys (see --armor). The default behav‐
2281 ior is not to use a comment string. --comment may be repeated
2282 multiple times to get multiple comment strings. --no-comments
2283 removes all comments. It is a good idea to keep the length of a
2284 single comment below 60 characters to avoid problems with mail
2285 programs wrapping such lines. Note that comment lines, like all
2286 other header lines, are not protected by the signature.
2287 --emit-version
2290 --no-emit-version
2292 Force inclusion of the version string in ASCII armored output.
2293 --no-emit-version disables this option.
2294 --sig-notation name=value
2297 --cert-notation name=value
2299 -N, --set-notation name=value
2301 Put the name value pair into the signature as notation data.
2302 name must consist only of printable characters or spaces, and
2303 must contain a '@' character in the form keyname@domain.exam‐
2304 ple.com (substituting the appropriate keyname and domain name,
2305 of course). This is to help prevent pollution of the IETF
2306 reserved notation namespace. The --expert flag overrides the '@'
2307 check. value may be any printable string; it will be encoded in
2308 UTF8, so you should check that your --display-charset is set
2309 correctly. If you prefix name with an exclamation mark (!), the
2310 notation data will be flagged as critical (rfc2440:5.2.3.15).
2311 --sig-notation sets a notation for data signatures. --cert-nota‐
2312 tion sets a notation for key signatures (certifications). --set-
2313 notation sets both.
2314 There are special codes that may be used in notation names. "%k"
2316 will be expanded into the key ID of the key being signed, "%K"
2317 into the long key ID of the key being signed, "%f" into the fin‐
2318 gerprint of the key being signed, "%s" into the key ID of the
2319 key making the signature, "%S" into the long key ID of the key
2320 making the signature, "%g" into the fingerprint of the key mak‐
2321 ing the signature (which might be a subkey), "%p" into the fin‐
2322 gerprint of the primary key of the key making the signature,
2323 "%c" into the signature count from the OpenPGP smartcard, and
2324 "%%" results in a single "%". %k, %K, and %f are only meaningful
2325 when making a key signature (certification), and %c is only
2326 meaningful when using the OpenPGP smartcard.
2327 --sig-policy-url string
2330 --cert-policy-url string
2332 --set-policy-url string
2334 Use string as a Policy URL for signatures (rfc2440:5.2.3.19).
2335 If you prefix it with an exclamation mark (!), the policy URL
2336 packet will be flagged as critical. --sig-policy-url sets a pol‐
2337 icy url for data signatures. --cert-policy-url sets a policy url
2338 for key signatures (certifications). --set-policy-url sets both.
2339 The same %-expandos used for notation data are available here as
2341 well.
2342 --sig-keyserver-url string
2345 Use string as a preferred keyserver URL for data signatures. If
2346 you prefix it with an exclamation mark (!), the keyserver URL
2347 packet will be flagged as critical.
2348 The same %-expandos used for notation data are available here as
2350 well.
2351 --set-filename string
2354 Use string as the filename which is stored inside messages.
2355 This overrides the default, which is to use the actual filename
2356 of the file being encrypted.
2357 --for-your-eyes-only
2360 --no-for-your-eyes-only
2362 Set the `for your eyes only' flag in the message. This causes
2363 GnuPG to refuse to save the file unless the --output option is
2364 given, and PGP to use a "secure viewer" with a claimed Tempest-
2365 resistant font to display the message. This option overrides
2366 --set-filename. --no-for-your-eyes-only disables this option.
2367 --use-embedded-filename
2370 --no-use-embedded-filename
2372 Try to create a file with a name as embedded in the data. This
2373 can be a dangerous option as it allows to overwrite files.
2374 Defaults to no.
2375 --cipher-algo name
2378 Use name as cipher algorithm. Running the program with the com‐
2379 mand --version yields a list of supported algorithms. If this is
2380 not used the cipher algorithm is selected from the preferences
2381 stored with the key. In general, you do not want to use this
2382 option as it allows you to violate the OpenPGP standard. --per‐
2383 sonal-cipher-preferences is the safe way to accomplish the same
2384 thing.
2385 --digest-algo name
2388 Use name as the message digest algorithm. Running the program
2389 with the command --version yields a list of supported algo‐
2390 rithms. In general, you do not want to use this option as it
2391 allows you to violate the OpenPGP standard. --personal-digest-
2392 preferences is the safe way to accomplish the same thing.
2393 --compress-algo name
2396 Use compression algorithm name. "zlib" is RFC-1950 ZLIB compres‐
2397 sion. "zip" is RFC-1951 ZIP compression which is used by PGP.
2398 "bzip2" is a more modern compression scheme that can compress
2399 some things better than zip or zlib, but at the cost of more
2400 memory used during compression and decompression. "uncompressed"
2401 or "none" disables compression. If this option is not used, the
2402 default behavior is to examine the recipient key preferences to
2403 see which algorithms the recipient supports. If all else fails,
2404 ZIP is used for maximum compatibility.
2405 ZLIB may give better compression results than ZIP, as the com‐
2407 pression window size is not limited to 8k. BZIP2 may give even
2408 better compression results than that, but will use a signifi‐
2409 cantly larger amount of memory while compressing and decompress‐
2410 ing. This may be significant in low memory situations. Note,
2411 however, that PGP (all versions) only supports ZIP compression.
2412 Using any algorithm other than ZIP or "none" will make the mes‐
2413 sage unreadable with PGP. In general, you do not want to use
2414 this option as it allows you to violate the OpenPGP standard.
2415 --personal-compress-preferences is the safe way to accomplish
2416 the same thing.
2417 --cert-digest-algo name
2420 Use name as the message digest algorithm used when signing a
2421 key. Running the program with the command --version yields a
2422 list of supported algorithms. Be aware that if you choose an
2423 algorithm that GnuPG supports but other OpenPGP implementations
2424 do not, then some users will not be able to use the key signa‐
2425 tures you make, or quite possibly your entire key.
2426 --disable-cipher-algo name
2429 Never allow the use of name as cipher algorithm. The given name
2430 will not be checked so that a later loaded algorithm will still
2431 get disabled.
2432 --disable-pubkey-algo name
2435 Never allow the use of name as public key algorithm. The given
2436 name will not be checked so that a later loaded algorithm will
2437 still get disabled.
2438 --throw-keyids
2441 --no-throw-keyids
2443 Do not put the recipient key IDs into encrypted messages. This
2444 helps to hide the receivers of the message and is a limited
2445 countermeasure against traffic analysis. ([Using a little social
2446 engineering anyone who is able to decrypt the message can check
2447 whether one of the other recipients is the one he suspects.])
2448 On the receiving side, it may slow down the decryption process
2449 because all available secret keys must be tried. --no-throw-
2450 keyids disables this option. This option is essentially the same
2451 as using --hidden-recipient for all recipients.
2452 --not-dash-escaped
2455 This option changes the behavior of cleartext signatures so that
2456 they can be used for patch files. You should not send such an
2457 armored file via email because all spaces and line endings are
2458 hashed too. You can not use this option for data which has 5
2459 dashes at the beginning of a line, patch files don't have this.
2460 A special armor header line tells GnuPG about this cleartext
2461 signature option.
2462 --escape-from-lines
2465 --no-escape-from-lines
2467 Because some mailers change lines starting with "From " to
2468 ">From " it is good to handle such lines in a special way when
2469 creating cleartext signatures to prevent the mail system from
2470 breaking the signature. Note that all other PGP versions do it
2471 this way too. Enabled by default. --no-escape-from-lines dis‐
2472 ables this option.
2473 --passphrase-repeat n
2476 Specify how many times gpg will request a new passphrase be
2477 repeated. This is useful for helping memorize a passphrase.
2478 Defaults to 1 repetition.
2479 --passphrase-fd n
2482 Read the passphrase from file descriptor n. Only the first line
2483 will be read from file descriptor n. If you use 0 for n, the
2484 passphrase will be read from STDIN. This can only be used if
2485 only one passphrase is supplied.
2486 --passphrase-file file
2489 Read the passphrase from file file. Only the first line will be
2490 read from file file. This can only be used if only one
2491 passphrase is supplied. Obviously, a passphrase stored in a file
2492 is of questionable security if other users can read this file.
2493 Don't use this option if you can avoid it.
2494 --passphrase string
2497 Use string as the passphrase. This can only be used if only one
2498 passphrase is supplied. Obviously, this is of very questionable
2499 security on a multi-user system. Don't use this option if you
2500 can avoid it.
2501 --command-fd n
2504 This is a replacement for the deprecated shared-memory IPC mode.
2505 If this option is enabled, user input on questions is not
2506 expected from the TTY but from the given file descriptor. It
2507 should be used together with --status-fd. See the file
2508 doc/DETAILS in the source distribution for details on how to use
2509 it.
2510 --command-file file
2513 Same as --command-fd, except the commands are read out of file
2514 file
2515 --allow-non-selfsigned-uid
2518 --no-allow-non-selfsigned-uid
2520 Allow the import and use of keys with user IDs which are not
2521 self-signed. This is not recommended, as a non self-signed user
2522 ID is trivial to forge. --no-allow-non-selfsigned-uid disables.
2523 --allow-freeform-uid
2526 Disable all checks on the form of the user ID while generating a
2527 new one. This option should only be used in very special envi‐
2528 ronments as it does not ensure the de-facto standard format of
2529 user IDs.
2530 --ignore-time-conflict
2533 GnuPG normally checks that the timestamps associated with keys
2534 and signatures have plausible values. However, sometimes a sig‐
2535 nature seems to be older than the key due to clock problems.
2536 This option makes these checks just a warning. See also
2537 --ignore-valid-from for timestamp issues on subkeys.
2538 --ignore-valid-from
2541 GnuPG normally does not select and use subkeys created in the
2542 future. This option allows the use of such keys and thus
2543 exhibits the pre-1.0.7 behaviour. You should not use this option
2544 unless you there is some clock problem. See also --ignore-time-
2545 conflict for timestamp issues with signatures.
2546 --ignore-crc-error
2549 The ASCII armor used by OpenPGP is protected by a CRC checksum
2550 against transmission errors. Occasionally the CRC gets mangled
2551 somewhere on the transmission channel but the actual content
2552 (which is protected by the OpenPGP protocol anyway) is still
2553 okay. This option allows GnuPG to ignore CRC errors.
2554 --ignore-mdc-error
2557 This option changes a MDC integrity protection failure into a
2558 warning. This can be useful if a message is partially corrupt,
2559 but it is necessary to get as much data as possible out of the
2560 corrupt message. However, be aware that a MDC protection fail‐
2561 ure may also mean that the message was tampered with intention‐
2562 ally by an attacker.
2563 --no-default-keyring
2566 Do not add the default keyrings to the list of keyrings. Note
2567 that GnuPG will not operate without any keyrings, so if you use
2568 this option and do not provide alternate keyrings via --keyring
2569 or --secret-keyring, then GnuPG will still use the default pub‐
2570 lic or secret keyrings.
2571 --skip-verify
2574 Skip the signature verification step. This may be used to make
2575 the decryption faster if the signature verification is not
2576 needed.
2577 --with-key-data
2580 Print key listings delimited by colons (like --with-colons) and
2581 print the public key data.
2582 --fast-list-mode
2585 Changes the output of the list commands to work faster; this is
2586 achieved by leaving some parts empty. Some applications don't
2587 need the user ID and the trust information given in the list‐
2588 ings. By using this options they can get a faster listing. The
2589 exact behaviour of this option may change in future versions.
2590 If you are missing some information, don't use this option.
2591 --no-literal
2594 This is not for normal use. Use the source to see for what it
2595 might be useful.
2596 --set-filesize
2599 This is not for normal use. Use the source to see for what it
2600 might be useful.
2601 --show-session-key
2604 Display the session key used for one message. See --override-
2605 session-key for the counterpart of this option.
2606 We think that Key Escrow is a Bad Thing; however the user should
2608 have the freedom to decide whether to go to prison or to reveal
2609 the content of one specific message without compromising all
2610 messages ever encrypted for one secret key. DON'T USE IT UNLESS
2611 YOU ARE REALLY FORCED TO DO SO.
2612 --override-session-key string
2615 Don't use the public key but the session key string. The format
2616 of this string is the same as the one printed by --show-session-
2617 key. This option is normally not used but comes handy in case
2618 someone forces you to reveal the content of an encrypted mes‐
2619 sage; using this option you can do this without handing out the
2620 secret key.
2621 --ask-sig-expire
2624 --no-ask-sig-expire
2626 When making a data signature, prompt for an expiration time. If
2627 this option is not specified, the expiration time set via
2628 --default-sig-expire is used. --no-ask-sig-expire disables this
2629 option.
2630 --default-sig-expire
2633 The default expiration time to use for signature expiration.
2634 Valid values are "0" for no expiration, a number followed by the
2635 letter d (for days), w (for weeks), m (for months), or y (for
2636 years) (for example "2m" for two months, or "5y" for five
2637 years), or an absolute date in the form YYYY-MM-DD. Defaults to
2638 "0".
2639 --ask-cert-expire
2642 --no-ask-cert-expire
2644 When making a key signature, prompt for an expiration time. If
2645 this option is not specified, the expiration time set via
2646 --default-cert-expire is used. --no-ask-cert-expire disables
2647 this option.
2648 --default-cert-expire
2651 The default expiration time to use for key signature expiration.
2652 Valid values are "0" for no expiration, a number followed by the
2653 letter d (for days), w (for weeks), m (for months), or y (for
2654 years) (for example "2m" for two months, or "5y" for five
2655 years), or an absolute date in the form YYYY-MM-DD. Defaults to
2656 "0".
2657 --allow-secret-key-import
2660 This is an obsolete option and is not used anywhere.
2661 --allow-multiple-messages
2664 --no-allow-multiple-messages
2666 Allow processing of multiple OpenPGP messages contained in a
2667 single file or stream. Some programs that call GPG are not pre‐
2668 pared to deal with multiple messages being processed together,
2669 so this option defaults to no. Note that versions of GPG prior
2670 to 1.4.7 always allowed multiple messages.
2671 Warning: Do not use this option unless you need it as a tempo‐
2673 rary workaround!
2674 --enable-special-filenames
2678 This options enables a mode in which filenames of the form
2679 `-&n', where n is a non-negative decimal number, refer to the
2680 file descriptor n and not to a file with that name.
2681 --no-expensive-trust-checks
2684 Experimental use only.
2685 --preserve-permissions
2688 Don't change the permissions of a secret keyring back to user
2689 read/write only. Use this option only if you really know what
2690 you are doing.
2691 --default-preference-list string
2694 Set the list of default preferences to string. This preference
2695 list is used for new keys and becomes the default for "setpref"
2696 in the edit menu.
2697 --default-keyserver-url name
2700 Set the default keyserver URL to name. This keyserver will be
2701 used as the keyserver URL when writing a new self-signature on a
2702 key, which includes key generation and changing preferences.
2703 --list-config
2706 Display various internal configuration parameters of GnuPG. This
2707 option is intended for external programs that call GnuPG to per‐
2708 form tasks, and is thus not generally useful. See the file
2709 `doc/DETAILS' in the source distribution for the details of
2710 which configuration items may be listed. --list-config is only
2711 usable with --with-colons set.
2712 --gpgconf-list
2715 This command is similar to --list-config but in general only
2716 internally used by the gpgconf tool.
2717 --gpgconf-test
2720 This is more or less dummy action. However it parses the con‐
2721 figuration file and returns with failure if the configuration
2722 file would prevent gpg from startup. Thus it may be used to run
2723 a syntax check on the configuration file.
2724 Deprecated options
2729 --load-extension name
2734 Load an extension module. If name does not contain a slash it is
2735 searched for in the directory configured when GnuPG was built
2736 (generally "/usr/local/lib/gnupg"). Extensions are not generally
2737 useful anymore, and the use of this option is deprecated.
2738 --show-photos
2741 --no-show-photos
2743 Causes --list-keys, --list-sigs, --list-public-keys, --list-
2744 secret-keys, and verifying a signature to also display the photo
2745 ID attached to the key, if any. See also --photo-viewer. These
2746 options are deprecated. Use --list-options [no-]show-photos
2747 and/or --verify-options [no-]show-photos instead.
2748 --show-keyring
2751 Display the keyring name at the head of key listings to show
2752 which keyring a given key resides on. This option is deprecated:
2753 use --list-options [no-]show-keyring instead.
2754 --ctapi-driver file
2757 Use file to access the smartcard reader. The current default is
2758 `libtowitoko.so'. Note that the use of this interface is depre‐
2759 cated; it may be removed in future releases.
2760 --always-trust
2763 Identical to --trust-model always. This option is deprecated.
2764 --show-notation
2767 --no-show-notation
2769 Show signature notations in the --list-sigs or --check-sigs
2770 listings as well as when verifying a signature with a notation
2771 in it. These options are deprecated. Use --list-options
2772 [no-]show-notation and/or --verify-options [no-]show-notation
2773 instead.
2774 --show-policy-url
2777 --no-show-policy-url
2779 Show policy URLs in the --list-sigs or --check-sigs listings as
2780 well as when verifying a signature with a policy URL in it.
2781 These options are deprecated. Use --list-options [no-]show-pol‐
2782 icy-url and/or --verify-options [no-]show-policy-url instead.
2783
2790 gpg -se -r Bob file
2791 sign and encrypt for user Bob
2792 gpg --clearsign file
2795 make a clear text signature
2796 gpg -sb file
2799 make a detached signature
2800 gpg -u 0x12345678 -sb file
2803 make a detached signature with the key 0x12345678
2804 gpg --list-keys user_ID
2807 show keys
2808 gpg --fingerprint user_ID
2811 show fingerprint
2812 gpg --verify pgpfile
2815 gpg --verify sigfile
2817 Verify the signature of the file but do not output the data. The
2818 second form is used for detached signatures, where sigfile is
2819 the detached signature (either ASCII armored or binary) and are
2820 the signed data; if this is not given, the name of the file
2821 holding the signed data is constructed by cutting off the exten‐
2822 sion (".asc" or ".sig") of sigfile or by asking the user for the
2823 filename.
2824
2829 There are different ways to specify a user ID to GnuPG. Some of them
2830 are only valid for gpg others are only good for gpgsm. Here is the
2831 entire list of ways to specify a key:
2832 By key Id.
2836 This format is deduced from the length of the string and its
2837 content or 0x prefix. The key Id of an X.509 certificate are the
2838 low 64 bits of its SHA-1 fingerprint. The use of key Ids is
2839 just a shortcut, for all automated processing the fingerprint
2840 should be used.
2841 When using gpg an exclamation mark (!) may be appended to force
2843 using the specified primary or secondary key and not to try and
2844 calculate which primary or secondary key to use.
2845 The last four lines of the example give the key ID in their long
2847 form as internally used by the OpenPGP protocol. You can see the
2848 long key ID using the option --with-colons.
2849 234567C4
2851 0F34E556E
2852 01347A56A
2853 0xAB123456
2854 234AABBCC34567C4
2856 0F323456784E56EAB
2857 01AB3FED1347A5612
2858 0x234AABBCC34567C4
2859 By fingerprint.
2864 This format is deduced from the length of the string and its
2865 content or the 0x prefix. Note, that only the 20 byte version
2866 fingerprint is available with gpgsm (i.e. the SHA-1 hash of the
2867 certificate).
2868 When using gpg an exclamation mark (!) may be appended to force
2870 using the specified primary or secondary key and not to try and
2871 calculate which primary or secondary key to use.
2872 The best way to specify a key Id is by using the fingerprint.
2874 This avoids any ambiguities in case that there are duplicated
2875 key IDs.
2876 1234343434343434C434343434343434
2878 123434343434343C3434343434343734349A3434
2879 0E12343434343434343434EAB3484343434343434
2880 0xE12343434343434343434EAB3484343434343434
2881 (gpgsm also accepts colons between each pair of hexadecimal digits
2884 because this is the de-facto standard on how to present X.509 finger‐
2885 prints.)
2886 By exact match on OpenPGP user ID.
2889 This is denoted by a leading equal sign. It does not make sense
2890 for X.509 certificates.
2891 =Heinrich Heine <heinrichh@uni-duesseldorf.de>
2893 By exact match on an email address.
2896 This is indicated by enclosing the email address in the usual
2897 way with left and right angles.
2898 <heinrichh@uni-duesseldorf.de>
2900 By word match.
2904 All words must match exactly (not case sensitive) but can appear
2905 in any order in the user ID or a subjects name. Words are any
2906 sequences of letters, digits, the underscore and all characters
2907 with bit 7 set.
2908 +Heinrich Heine duesseldorf
2910 By exact match on the subject's DN.
2913 This is indicated by a leading slash, directly followed by the
2914 RFC-2253 encoded DN of the subject. Note that you can't use the
2915 string printed by "gpgsm --list-keys" because that one as been
2916 reordered and modified for better readability; use --with-colons
2917 to print the raw (but standard escaped) RFC-2253 string
2918 /CN=Heinrich Heine,O=Poets,L=Paris,C=FR
2920 By exact match on the issuer's DN.
2923 This is indicated by a leading hash mark, directly followed by a
2924 slash and then directly followed by the rfc2253 encoded DN of
2925 the issuer. This should return the Root cert of the issuer.
2926 See note above.
2927 #/CN=Root Cert,O=Poets,L=Paris,C=FR
2929 By exact match on serial number and issuer's DN.
2933 This is indicated by a hash mark, followed by the hexadecimal
2934 representation of the serial number, then followed by a slash
2935 and the RFC-2253 encoded DN of the issuer. See note above.
2936 #4F03/CN=Root Cert,O=Poets,L=Paris,C=FR
2938 By keygrip
2941 This is indicated by an ampersand followed by the 40 hex digits
2942 of a keygrip. gpgsm prints the keygrip when using the command
2943 --dump-cert. It does not yet work for OpenPGP keys.
2944 &D75F22C3F86E355877348498CDC92BD21010A480
2946 By substring match.
2950 This is the default mode but applications may want to explicitly
2951 indicate this by putting the asterisk in front. Match is not
2952 case sensitive.
2953 Heine
2955 *Heine
2956 Please note that we have reused the hash mark identifier which was used
2960 in old GnuPG versions to indicate the so called local-id. It is not
2961 anymore used and there should be no conflict when used with X.509
2962 stuff.
2963 Using the RFC-2253 format of DNs has the drawback that it is not possi‐
2965 ble to map them back to the original encoding, however we don't have to
2966 do this because our key database stores this encoding as meta data.
2967
2973 There are a few configuration files to control certain aspects of gpg's
2974 operation. Unless noted, they are expected in the current home direc‐
2975 tory (see: [option --homedir]).
2976 gpg.conf
2980 This is the standard configuration file read by gpg on startup.
2981 It may contain any valid long option; the leading two dashes may
2982 not be entered and the option may not be abbreviated. This
2983 default name may be changed on the command line (see: [option
2984 --options]). You should backup this file.
2985 Note that on larger installations, it is useful to put predefined files
2988 into the directory `/etc/skel/.gnupg/' so that newly created users
2989 start up with a working configuration.
2990 For internal purposes gpg creates and maintains a few other files; They
2992 all live in in the current home directory (see: [option --homedir]).
2993 Only the gpg may modify these files.
2994 ~/.gnupg/secring.gpg
2998 The secret keyring. You should backup this file.
2999 ~/.gnupg/secring.gpg.lock
3002 The lock file for the secret keyring.
3003 ~/.gnupg/pubring.gpg
3006 The public keyring. You should backup this file.
3007 ~/.gnupg/pubring.gpg.lock
3010 The lock file for the public keyring.
3011 ~/.gnupg/trustdb.gpg
3014 The trust database. There is no need to backup this file; it is
3015 better to backup the ownertrust values (see: [option --export-
3016 ownertrust]).
3017 ~/.gnupg/trustdb.gpg.lock
3020 The lock file for the trust database.
3021 ~/.gnupg/random_seed
3024 A file used to preserve the state of the internal random pool.
3025 /usr[/local]/share/gnupg/options.skel
3028 The skeleton options file.
3029 /usr[/local]/lib/gnupg/
3032 Default location for extensions.
3033 Operation is further controlled by a few environment variables:
3036 HOME Used to locate the default home directory.
3040 GNUPGHOME
3043 If set directory used instead of "~/.gnupg".
3044 GPG_AGENT_INFO
3047 Used to locate the gpg-agent. This is only honored when --use-
3048 agent is set. The value consists of 3 colon delimited fields:
3049 The first is the path to the Unix Domain Socket, the second the
3050 PID of the gpg-agent and the protocol version which should be
3051 set to 1. When starting the gpg-agent as described in its docu‐
3052 mentation, this variable is set to the correct value. The option
3053 --gpg-agent-info can be used to override it.
3054 PINENTRY_USER_DATA
3057 This value is passed via gpg-agent to pinentry. It is useful to
3058 convey extra information to a custom pinentry.
3059 COLUMNS
3062 LINES Used to size some displays to the full size of the screen.
3064 LANGUAGE
3068 Apart from its use by GNU, it is used in the W32 version to
3069 override the language selection done through the Registry. If
3070 used and set to a valid and available language name (langid),
3071 the file with the translation is loaded from
3072 gpgdir/gnupg.nls/langid.mo. Here gpgdir is the directory out of
3073 which the gpg binary has been loaded. If it can't be loaded the
3074 Registry is tried and as last resort the native Windows locale
3075 system is used.
3076
3082 On older systems this program should be installed as setuid(root). This
3083 is necessary to lock memory pages. Locking memory pages prevents the
3084 operating system from writing memory pages (which may contain
3085 passphrases or other sensitive material) to disk. If you get no warning
3086 message about insecure memory your operating system supports locking
3087 without being root. The program drops root privileges as soon as locked
3088 memory is allocated.
3089 Note also that some systems (especially laptops) have the ability to
3091 ``suspend to disk'' (also known as ``safe sleep'' or ``hibernate'').
3092 This writes all memory to disk before going into a low power or even
3093 powered off mode. Unless measures are taken in the operating system to
3094 protect the saved memory, passphrases or other sensitive material may
3095 be recoverable from it later.
3096 Before you report a bug you should first search the mailing list ar‐
3098 chives for similar problems and second check whether such a bug has
3099 already been reported to our bug tracker at http://bugs.gnupg.org .
3100
3103 gpgv(1),
3104 The full documentation for this tool is maintained as a Texinfo manual.
3106 If GnuPG and the info program are properly installed at your site, the
3107 command
3108 info gnupg
3110 should give you access to the complete manual including a menu struc‐
3112 ture and an index.
3113GnuPG 1.4.11 2010-10-21 GPG(1)