1GPG2(1) GNU Privacy Guard GPG2(1)
2
6 gpg2 - OpenPGP encryption and signing tool
7
9 gpg2 [--homedir dir] [--options file] [options] command [args]
10
13 gpg2 is the OpenPGP part of the GNU Privacy Guard (GnuPG). It is a tool
14 to provide digital encryption and signing services using the OpenPGP
15 standard. gpg2 features complete key management and all bells and whis‐
16 tles you can expect from a decent OpenPGP implementation.
17 In contrast to the standalone version gpg, which is more suited for
20 server and embedded platforms, this version is installed under the name
21 gpg2 and more targeted to the desktop as it requires several other mod‐
22 ules to be installed. The standalone version will be kept maintained
23 and it is possible to install both versions on the same system. If you
24 need to use different configuration files, you should make use of some‐
25 thing like ‘gpg.conf-2’ instead of just ‘gpg.conf’.
26
34 The program returns 0 if everything was fine, 1 if at least a signature
35 was bad, and other error codes for fatal errors.
36
39 Use a *good* password for your user account and a *good* passphrase to
40 protect your secret key. This passphrase is the weakest part of the
41 whole system. Programs to do dictionary attacks on your secret keyring
42 are very easy to write and so you should protect your "~/.gnupg/"
43 directory very well.
44 Keep in mind that, if this program is used over a network (telnet), it
46 is *very* easy to spy out your passphrase!
47 If you are going to verify detached signatures, make sure that the pro‐
49 gram knows about it; either give both filenames on the command line or
50 use '-' to specify STDIN.
51
54 GnuPG tries to be a very flexible implementation of the OpenPGP stan‐
55 dard. In particular, GnuPG implements many of the optional parts of the
56 standard, such as the SHA-512 hash, and the ZLIB and BZIP2 compression
57 algorithms. It is important to be aware that not all OpenPGP programs
58 implement these optional algorithms and that by forcing their use via
59 the --cipher-algo, --digest-algo, --cert-digest-algo, or --compress-
60 algo options in GnuPG, it is possible to create a perfectly valid
61 OpenPGP message, but one that cannot be read by the intended recipient.
62 There are dozens of variations of OpenPGP programs available, and each
64 supports a slightly different subset of these optional algorithms. For
65 example, until recently, no (unhacked) version of PGP supported the
66 BLOWFISH cipher algorithm. A message using BLOWFISH simply could not be
67 read by a PGP user. By default, GnuPG uses the standard OpenPGP prefer‐
68 ences system that will always do the right thing and create messages
69 that are usable by all recipients, regardless of which OpenPGP program
70 they use. Only override this safe default if you really know what you
71 are doing.
72 If you absolutely must override the safe default, or if the preferences
74 on a given key are invalid for some reason, you are far better off
75 using the --pgp6, --pgp7, or --pgp8 options. These options are safe as
76 they do not force any particular algorithms in violation of OpenPGP,
77 but rather reduce the available algorithms to a "PGP-safe" list.
78
81 Commands are not distinguished from options except for the fact that
82 only one command is allowed.
83 gpg2 may be run with no commands, in which case it will perform a rea‐
85 sonable action depending on the type of file it is given as input (an
86 encrypted message is decrypted, a signature is verified, a file con‐
87 taining keys is listed).
88 Please remember that option as well as command parsing stops as soon as
90 a non-option is encountered, you can explicitly stop parsing by using
91 the special option --.
92 Commands not specific to the function
99 --version
103 Print the program version and licensing information. Note that
104 you cannot abbreviate this command.
105 --help
108 -h Print a usage message summarizing the most useful command line
110 options. Note that you cannot abbreviate this command.
111 --warranty
114 Print warranty information.
115 --dump-options
118 Print a list of all available options and commands. Note that
119 you cannot abbreviate this command.
120 Commands to select the type of operation
125 --sign
131 -s Make a signature. This command may be combined with --encrypt
133 (for a signed and encrypted message), --symmetric (for a signed
134 and symmetrically encrypted message), or --encrypt and --symmet‐
135 ric together (for a signed message that may be decrypted via a
136 secret key or a passphrase). The key to be used for signing is
137 chosen by default or can be set with the --local-user and
138 --default-key options.
139 --clearsign
142 Make a clear text signature. The content in a clear text signa‐
143 ture is readable without any special software. OpenPGP software
144 is only needed to verify the signature. Clear text signatures
145 may modify end-of-line whitespace for platform independence and
146 are not intended to be reversible. The key to be used for sign‐
147 ing is chosen by default or can be set with the --local-user and
148 --default-key options.
149 --detach-sign
153 -b Make a detached signature.
155 --encrypt
158 -e Encrypt data. This option may be combined with --sign (for a
160 signed and encrypted message), --symmetric (for a message that
161 may be decrypted via a secret key or a passphrase), or --sign
162 and --symmetric together (for a signed message that may be
163 decrypted via a secret key or a passphrase).
164 --symmetric
167 -c Encrypt with a symmetric cipher using a passphrase. The default
169 symmetric cipher used is CAST5, but may be chosen with the
170 --cipher-algo option. This option may be combined with --sign
171 (for a signed and symmetrically encrypted message), --encrypt
172 (for a message that may be decrypted via a secret key or a
173 passphrase), or --sign and --encrypt together (for a signed mes‐
174 sage that may be decrypted via a secret key or a passphrase).
175 --store
178 Store only (make a simple RFC1991 literal data packet).
179 --decrypt
182 -d Decrypt the file given on the command line (or STDIN if no file
184 is specified) and write it to STDOUT (or the file specified with
185 --output). If the decrypted file is signed, the signature is
186 also verified. This command differs from the default operation,
187 as it never writes to the filename which is included in the file
188 and it rejects files which don't begin with an encrypted mes‐
189 sage.
190 --verify
193 Assume that the first argument is a signed file or a detached
194 signature and verify it without generating any output. With no
195 arguments, the signature packet is read from STDIN. If only a
196 sigfile is given, it may be a complete signature or a detached
197 signature, in which case the signed stuff is expected in a file
198 without the ".sig" or ".asc" extension. With more than 1 argu‐
199 ment, the first should be a detached signature and the remaining
200 files are the signed stuff. To read the signed stuff from STDIN,
201 use '-' as the second filename. For security reasons a detached
202 signature cannot read the signed material from STDIN without
203 denoting it in the above way.
204 --multifile
207 This modifies certain other commands to accept multiple files
208 for processing on the command line or read from STDIN with each
209 filename on a separate line. This allows for many files to be
210 processed at once. --multifile may currently be used along with
211 --verify, --encrypt, and --decrypt. Note that --multifile --ver‐
212 ify may not be used with detached signatures.
213 --verify-files
216 Identical to --multifile --verify.
217 --encrypt-files
220 Identical to --multifile --encrypt.
221 --decrypt-files
224 Identical to --multifile --decrypt.
225 --list-keys
228 -k
230 --list-public-keys
232 List all keys from the public keyrings, or just the keys given
233 on the command line.
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. This
251 command has the same effect as using --list-keys with --with-
252 sig-list.
253 For each signature listed, there are several flags in between
255 the "sig" tag and keyid. These flags give additional information
256 about each signature. From left to right, they are the numbers
257 1-3 for certificate check level (see --ask-cert-level), "L" for
258 a local or non-exportable signature (see --lsign-key), "R" for a
259 nonRevocable signature (see the --edit-key command "nrsign"),
260 "P" for a signature that contains a policy URL (see --cert-pol‐
261 icy-url), "N" for a signature that contains a notation (see
262 --cert-notation), "X" for an eXpired signature (see --ask-cert-
263 expire), and the numbers 1-9 or "T" for 10 and above to indicate
264 trust signature levels (see the --edit-key command "tsign").
265 --check-sigs
268 Same as --list-sigs, but the signatures are verified. Note that
269 for performance reasons the revocation status of a signing key
270 is not shown. This command has the same effect as using --list-
271 keys with --with-sig-check.
272 The status of the verification is indicated by a flag directly
274 following the "sig" tag (and thus before the flags described
275 above for --list-sigs). A "!" indicates that the signature has
276 been successfully verified, a "-" denotes a bad signature and a
277 "%" is used if an error occurred while checking the signature
278 (e.g. a non supported algorithm).
279 --locate-keys
282 Locate the keys given as arguments. This command basically uses
283 the same algorithm as used when locating keys for encryption or
284 signing and may thus be used to see what keys gpg2 might use.
285 In particular external methods as defined by --auto-key-locate
286 may be used to locate a key. Only public keys are listed.
287 --fingerprint
291 List all keys (or the specified ones) along with their finger‐
292 prints. This is the same output as --list-keys but with the
293 additional output of a line with the fingerprint. May also be
294 combined with --list-sigs or --check-sigs. If this command is
295 given twice, the fingerprints of all secondary keys are listed
296 too.
297 --list-packets
300 List only the sequence of packets. This is mainly useful for
301 debugging.
302 --card-edit
306 Present a menu to work with a smartcard. The subcommand "help"
307 provides an overview on available commands. For a detailed
308 description, please see the Card HOWTO at
309 http://www.gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .
310 --card-status
313 Show the content of the smart card.
314 --change-pin
317 Present a menu to allow changing the PIN of a smartcard. This
318 functionality is also available as the subcommand "passwd" with
319 the --card-edit command.
320 --delete-key name
323 Remove key from the public keyring. In batch mode either --yes
324 is required or the key must be specified by fingerprint. This is
325 a safeguard against accidental deletion of multiple keys.
326 --delete-secret-key name
329 Remove key from the secret and public keyring. In batch mode the
330 key must be specified by fingerprint.
331 --delete-secret-and-public-key name
334 Same as --delete-key, but if a secret key exists, it will be
335 removed first. In batch mode the key must be specified by fin‐
336 gerprint.
337 --export
340 Either export all keys from all keyrings (default keyrings and
341 those registered via option --keyring), or if at least one name
342 is given, those of the given name. The new keyring is written to
343 STDOUT or to the file given with option --output. Use together
344 with --armor to mail those keys.
345 --send-keys key IDs
348 Similar to --export but sends the keys to a keyserver. Finger‐
349 prints may be used instead of key IDs. Option --keyserver must
350 be used to give the name of this keyserver. Don't send your com‐
351 plete keyring to a keyserver --- select only those keys which
352 are new or changed by you. If no key IDs are given, gpg does
353 nothing.
354 --export-secret-keys
357 --export-secret-subkeys
359 Same as --export, but exports the secret keys instead. This is
360 normally not very useful and a security risk. The second form
361 of the command has the special property to render the secret
362 part of the primary key useless; this is a GNU extension to
363 OpenPGP and other implementations can not be expected to suc‐
364 cessfully import such a key. See the option --simple-sk-check‐
365 sum if you want to import such an exported key with an older
366 OpenPGP implementation.
367 --import
370 --fast-import
372 Import/merge keys. This adds the given keys to the keyring. The
373 fast version is currently just a synonym.
374 There are a few other options which control how this command
376 works. Most notable here is the --import-options merge-only
377 option which does not insert new keys but does only the merging
378 of new signatures, user-IDs and subkeys.
379 --recv-keys key IDs
382 Import the keys with the given key IDs from a keyserver. Option
383 --keyserver must be used to give the name of this keyserver.
384 --refresh-keys
387 Request updates from a keyserver for keys that already exist on
388 the local keyring. This is useful for updating a key with the
389 latest signatures, user IDs, etc. Calling this with no arguments
390 will refresh the entire keyring. Option --keyserver must be used
391 to give the name of the keyserver for all keys that do not have
392 preferred keyservers set (see --keyserver-options honor-key‐
393 server-url).
394 --search-keys names
397 Search the keyserver for the given names. Multiple names given
398 here will be joined together to create the search string for the
399 keyserver. Option --keyserver must be used to give the name of
400 this keyserver. Keyservers that support different search meth‐
401 ods allow using the syntax specified in "How to specify a user
402 ID" below. Note that different keyserver types support different
403 search methods. Currently only LDAP supports them all.
404 --fetch-keys URIs
407 Retrieve keys located at the specified URIs. Note that different
408 installations of GnuPG may support different protocols (HTTP,
409 FTP, LDAP, etc.)
410 --update-trustdb
413 Do trust database maintenance. This command iterates over all
414 keys and builds the Web of Trust. This is an interactive command
415 because it may have to ask for the "ownertrust" values for keys.
416 The user has to give an estimation of how far she trusts the
417 owner of the displayed key to correctly certify (sign) other
418 keys. GnuPG only asks for the ownertrust value if it has not yet
419 been assigned to a key. Using the --edit-key menu, the assigned
420 value can be changed at any time.
421 --check-trustdb
424 Do trust database maintenance without user interaction. From
425 time to time the trust database must be updated so that expired
426 keys or signatures and the resulting changes in the Web of Trust
427 can be tracked. Normally, GnuPG will calculate when this is
428 required and do it automatically unless --no-auto-check-trustdb
429 is set. This command can be used to force a trust database check
430 at any time. The processing is identical to that of --update-
431 trustdb but it skips keys with a not yet defined "ownertrust".
432 For use with cron jobs, this command can be used together with
434 --batch in which case the trust database check is done only if a
435 check is needed. To force a run even in batch mode add the
436 option --yes.
437 --export-ownertrust
441 Send the ownertrust values to STDOUT. This is useful for backup
442 purposes as these values are the only ones which can't be re-
443 created from a corrupted trustdb. Example:
444 gpg2 --export-ownertrust > otrust.txt
445 --import-ownertrust
449 Update the trustdb with the ownertrust values stored in files
450 (or STDIN if not given); existing values will be overwritten.
451 In case of a severely damaged trustdb and if you have a recent
452 backup of the ownertrust values (e.g. in the file ‘otrust.txt’,
453 you may re-create the trustdb using these commands:
454 cd ~/.gnupg
455 rm trustdb.gpg
456 gpg2 --import-ownertrust < otrust.txt
457 --rebuild-keydb-caches
461 When updating from version 1.0.6 to 1.0.7 this command should be
462 used to create signature caches in the keyring. It might be
463 handy in other situations too.
464 --print-md algo
467 --print-mds
469 Print message digest of algorithm ALGO for all given files or
470 STDIN. With the second form (or a deprecated "*" as algo)
471 digests for all available algorithms are printed.
472 --gen-random 0|1|2
475 Emit count random bytes of the given quality level. If count is
476 not given or zero, an endless sequence of random bytes will be
477 emitted. PLEASE, don't use this command unless you know what
478 you are doing; it may remove precious entropy from the system!
479 --gen-prime mode bits
482 Use the source, Luke :-). The output format is still subject to
483 change.
484 --enarmor
488 --dearmor
490 Pack or unpack an arbitrary input into/from an OpenPGP ASCII
491 armor. This is a GnuPG extension to OpenPGP and in general not
492 very useful.
493 How to manage your keys
499 This section explains the main commands for key management
502 --gen-key
506 Generate a new key pair. This command is normally only used
507 interactively.
508 There is an experimental feature which allows you to create keys
510 in batch mode. See the file ‘doc/DETAILS’ in the source distri‐
511 bution on how to use this.
512 --gen-revoke name
515 Generate a revocation certificate for the complete key. To
516 revoke a subkey or a signature, use the --edit command.
517 --desig-revoke name
520 Generate a designated revocation certificate for a key. This
521 allows a user (with the permission of the keyholder) to revoke
522 someone else's key.
523 --edit-key
527 Present a menu which enables you to do most of the key manage‐
528 ment related tasks. It expects the specification of a key on
529 the command line.
530 uid n Toggle selection of user ID or photographic user ID with
534 index n. Use * to select all and 0 to deselect all.
535 key n Toggle selection of subkey with index n. Use * to select
538 all and 0 to deselect all.
539 sign Make a signature on key of user name If the key is not
542 yet signed by the default user (or the users given with
543 -u), the program displays the information of the key
544 again, together with its fingerprint and asks whether it
545 should be signed. This question is repeated for all users
546 specified with -u.
547 lsign Same as "sign" but the signature is marked as non-
550 exportable and will therefore never be used by others.
551 This may be used to make keys valid only in the local
552 environment.
553 nrsign Same as "sign" but the signature is marked as non-revoca‐
556 ble and can therefore never be revoked.
557 tsign Make a trust signature. This is a signature that combines
560 the notions of certification (like a regular signature),
561 and trust (like the "trust" command). It is generally
562 only useful in distinct communities or groups.
563 Note that "l" (for local / non-exportable), "nr" (for non-revo‐
565 cable, and "t" (for trust) may be freely mixed and prefixed to
566 "sign" to create a signature of any type desired.
567 delsig Delete a signature. Note that it is not possible to
571 retract a signature, once it has been send to the public
572 (i.e. to a keyserver). In that case you better use
573 revsig.
574 revsig Revoke a signature. For every signature which has been
577 generated by one of the secret keys, GnuPG asks whether a
578 revocation certificate should be generated.
579 check Check the signatures on all selected user IDs.
582 adduid Create an additional user ID.
585 addphoto
588 Create a photographic user ID. This will prompt for a
589 JPEG file that will be embedded into the user ID. Note
590 that a very large JPEG will make for a very large key.
591 Also note that some programs will display your JPEG
592 unchanged (GnuPG), and some programs will scale it to fit
593 in a dialog box (PGP).
594 showphoto
597 Display the selected photographic user ID.
598 deluid Delete a user ID or photographic user ID. Note that it
601 is not possible to retract a user id, once it has been
602 send to the public (i.e. to a keyserver). In that case
603 you better use revuid.
604 revuid Revoke a user ID or photographic user ID.
607 primary
610 Flag the current user id as the primary one, removes the
611 primary user id flag from all other user ids and sets the
612 timestamp of all affected self-signatures one second
613 ahead. Note that setting a photo user ID as primary makes
614 it primary over other photo user IDs, and setting a regu‐
615 lar user ID as primary makes it primary over other regu‐
616 lar user IDs.
617 keyserver
620 Set a preferred keyserver for the specified user ID(s).
621 This allows other users to know where you prefer they get
622 your key from. See --keyserver-options honor-keyserver-
623 url for more on how this works. Setting a value of
624 "none" removes an existing preferred keyserver.
625 notation
628 Set a name=value notation for the specified user ID(s).
629 See --cert-notation for more on how this works. Setting a
630 value of "none" removes all notations, setting a notation
631 prefixed with a minus sign (-) removes that notation, and
632 setting a notation name (without the =value) prefixed
633 with a minus sign removes all notations with that name.
634 pref List preferences from the selected user ID. This shows
637 the actual preferences, without including any implied
638 preferences.
639 showpref
642 More verbose preferences listing for the selected user
643 ID. This shows the preferences in effect by including the
644 implied preferences of 3DES (cipher), SHA-1 (digest), and
645 Uncompressed (compression) if they are not already
646 included in the preference list. In addition, the pre‐
647 ferred keyserver and signature notations (if any) are
648 shown.
649 setpref string
652 Set the list of user ID preferences to string for all (or
653 just the selected) user IDs. Calling setpref with no
654 arguments sets the preference list to the default (either
655 built-in or set via --default-preference-list), and call‐
656 ing setpref with "none" as the argument sets an empty
657 preference list. Use gpg2 --version to get a list of
658 available algorithms. Note that while you can change the
659 preferences on an attribute user ID (aka "photo ID"),
660 GnuPG does not select keys via attribute user IDs so
661 these preferences will not be used by GnuPG.
662 When setting preferences, you should list the algorithms
664 in the order which you'd like to see them used by someone
665 else when encrypting a message to your key. If you don't
666 include 3DES, it will be automatically added at the end.
667 Note that there are many factors that go into choosing an
668 algorithm (for example, your key may not be the only
669 recipient), and so the remote OpenPGP application being
670 used to send to you may or may not follow your exact cho‐
671 sen order for a given message. It will, however, only
672 choose an algorithm that is present on the preference
673 list of every recipient key. See also the INTEROPERABIL‐
674 ITY WITH OTHER OPENPGP PROGRAMS section below.
675 addkey Add a subkey to this key.
678 addcardkey
681 Generate a subkey on a card and add it to this key.
682 keytocard
685 Transfer the selected secret subkey (or the primary key
686 if no subkey has been selected) to a smartcard. The
687 secret key in the keyring will be replaced by a stub if
688 the key could be stored successfully on the card and you
689 use the save command later. Only certain key types may be
690 transferred to the card. A sub menu allows you to select
691 on what card to store the key. Note that it is not possi‐
692 ble to get that key back from the card - if the card gets
693 broken your secret key will be lost unless you have a
694 backup somewhere.
695 bkuptocard file
698 Restore the given file to a card. This command may be
699 used to restore a backup key (as generated during card
700 initialization) to a new card. In almost all cases this
701 will be the encryption key. You should use this command
702 only with the corresponding public key and make sure that
703 the file given as argument is indeed the backup to
704 restore. You should then select 2 to restore as encryp‐
705 tion key. You will first be asked to enter the
706 passphrase of the backup key and then for the Admin PIN
707 of the card.
708 delkey Remove a subkey (secondart key). Note that it is not pos‐
711 sible to retract a subkey, once it has been send to the
712 public (i.e. to a keyserver). In that case you better
713 use revkey.
714 revkey Revoke a subkey.
717 expire Change the key or subkey expiration time. If a subkey is
720 selected, the expiration time of this subkey will be
721 changed. With no selection, the key expiration of the
722 primary key is changed.
723 trust Change the owner trust value for the key. This updates
726 the trust-db immediately and no save is required.
727 disable
730 enable Disable or enable an entire key. A disabled key can not
732 normally be used for encryption.
733 addrevoker
736 Add a designated revoker to the key. This takes one
737 optional argument: "sensitive". If a designated revoker
738 is marked as sensitive, it will not be exported by
739 default (see export-options).
740 passwd Change the passphrase of the secret key.
743 toggle Toggle between public and secret key listing.
746 clean Compact (by removing all signatures except the selfsig)
749 any user ID that is no longer usable (e.g. revoked, or
750 expired). Then, remove any signatures that are not usable
751 by the trust calculations. Specifically, this removes
752 any signature that does not validate, any signature that
753 is superseded by a later signature, revoked signatures,
754 and signatures issued by keys that are not present on the
755 keyring.
756 minimize
759 Make the key as small as possible. This removes all sig‐
760 natures from each user ID except for the most recent
761 self-signature.
762 cross-certify
765 Add cross-certification signatures to signing subkeys
766 that may not currently have them. Cross-certification
767 signatures protect against a subtle attack against sign‐
768 ing subkeys. See --require-cross-certification. All new
769 keys generated have this signature by default, so this
770 option is only useful to bring older keys up to date.
771 save Save all changes to the key rings and quit.
774 quit Quit the program without updating the key rings.
777 The listing shows you the key with its secondary keys and all
780 user ids. Selected keys or user ids are indicated by an aster‐
781 isk. The trust value is displayed with the primary key: the
782 first is the assigned owner trust and the second is the calcu‐
783 lated trust value. Letters are used for the values:
784 - No ownertrust assigned / not yet calculated.
788 e Trust calculation has failed; probably due to an expired
791 key.
792 q Not enough information for calculation.
795 n Never trust this key.
798 m Marginally trusted.
801 f Fully trusted.
804 u Ultimately trusted.
807 --sign-key name
810 Signs a public key with your secret key. This is a shortcut ver‐
811 sion of the subcommand "sign" from --edit.
812 --lsign-key name
815 Signs a public key with your secret key but marks it as non-
816 exportable. This is a shortcut version of the subcommand "lsign"
817 from --edit-key.
818
825 gpg2 comes features a bunch of options to control the exact behaviour
826 and to change the default configuration.
827 Long options can be put in an options file (default
830 "~/.gnupg/gpg.conf"). Short option names will not work - for example,
831 "armor" is a valid option for the options file, while "a" is not. Do
832 not write the 2 dashes, but simply the name of the option and any
833 required arguments. Lines with a hash ('#') as the first non-white-
834 space character are ignored. Commands may be put in this file too, but
835 that is not generally useful as the command will execute automatically
836 with every execution of gpg.
837 Please remember that option parsing stops as soon as a non-option is
839 encountered, you can explicitly stop parsing by using the special
840 option --.
841 How to change the configuration
845 These options are used to change the configuration and are usually
848 found in the option file.
849 --default-key name
853 Use name as the default key to sign with. If this option is not
854 used, the default key is the first key found in the secret
855 keyring. Note that -u or --local-user overrides this option.
856 --default-recipient name
859 Use name as default recipient if option --recipient is not used
860 and don't ask if this is a valid one. name must be non-empty.
861 --default-recipient-self
864 Use the default key as default recipient if option --recipient
865 is not used and don't ask if this is a valid one. The default
866 key is the first one from the secret keyring or the one set with
867 --default-key.
868 --no-default-recipient
871 Reset --default-recipient and --default-recipient-self.
872 -v, --verbose
875 Give more information during processing. If used twice, the
876 input data is listed in detail.
877 --no-verbose
880 Reset verbose level to 0.
881 -q, --quiet
884 Try to be as quiet as possible.
885 --batch
888 --no-batch
890 Use batch mode. Never ask, do not allow interactive commands.
891 --no-batch disables this option. Note that even with a filename
892 given on the command line, gpg might still need to read from
893 STDIN (in particular if gpg figures that the input is a detached
894 signature and no data file has been specified). Thus if you do
895 not want to feed data via STDIN, you should connect STDIN to
896 ‘/dev/null’.
897 --no-tty
900 Make sure that the TTY (terminal) is never used for any output.
901 This option is needed in some cases because GnuPG sometimes
902 prints warnings to the TTY even if --batch is used.
903 --yes Assume "yes" on most questions.
906 --no Assume "no" on most questions.
909 --list-options parameters
913 This is a space or comma delimited string that gives options
914 used when listing keys and signatures (that is, --list-keys,
915 --list-sigs, --list-public-keys, --list-secret-keys, and the
916 --edit-key functions). Options can be prepended with a no-
917 (after the two dashes) to give the opposite meaning. The
918 options are:
919 show-photos
923 Causes --list-keys, --list-sigs, --list-public-keys, and
924 --list-secret-keys to display any photo IDs attached to
925 the key. Defaults to no. See also --photo-viewer.
926 show-policy-urls
929 Show policy URLs in the --list-sigs or --check-sigs list‐
930 ings. Defaults to no.
931 show-notations
934 show-std-notations
936 show-user-notations
938 Show all, IETF standard, or user-defined signature nota‐
939 tions in the --list-sigs or --check-sigs listings.
940 Defaults to no.
941 show-keyserver-urls
944 Show any preferred keyserver URL in the --list-sigs or
946 --check-sigs listings. Defaults to no.
947 show-uid-validity
950 Display the calculated validity of user IDs during key
951 listings. Defaults to no.
952 show-unusable-uids
955 Show revoked and expired user IDs in key listings.
956 Defaults to no.
957 show-unusable-subkeys
960 Show revoked and expired subkeys in key listings.
961 Defaults to no.
962 show-keyring
965 Display the keyring name at the head of key listings to
966 show which keyring a given key resides on. Defaults to
967 no.
968 show-sig-expire
971 Show signature expiration dates (if any) during --list-
972 sigs or --check-sigs listings. Defaults to no.
973 show-sig-subpackets
976 Include signature subpackets in the key listing. This
977 option can take an optional argument list of the subpack‐
978 ets to list. If no argument is passed, list all subpack‐
979 ets. Defaults to no. This option is only meaningful when
980 using --with-colons along with --list-sigs or --check-
981 sigs.
982 --verify-options parameters
985 This is a space or comma delimited string that gives options
986 used when verifying signatures. Options can be prepended with a
987 `no-' to give the opposite meaning. The options are:
988 show-photos
992 Display any photo IDs present on the key that issued the
993 signature. Defaults to no. See also --photo-viewer.
994 show-policy-urls
997 Show policy URLs in the signature being verified.
998 Defaults to no.
999 show-notations
1002 show-std-notations
1004 show-user-notations
1006 Show all, IETF standard, or user-defined signature nota‐
1007 tions in the signature being verified. Defaults to IETF
1008 standard.
1009 show-keyserver-urls
1012 Show any preferred keyserver URL in the signature being
1013 verified. Defaults to no.
1014 show-uid-validity
1017 Display the calculated validity of the user IDs on the
1018 key that issued the signature. Defaults to no.
1019 show-unusable-uids
1022 Show revoked and expired user IDs during signature veri‐
1023 fication. Defaults to no.
1024 show-primary-uid-only
1027 Show only the primary user ID during signature verifica‐
1028 tion. That is all the AKA lines as well as photo Ids are
1029 not shown with the signature verification status.
1030 pka-lookups
1033 Enable PKA lookups to verify sender addresses. Note that
1034 PKA is based on DNS, and so enabling this option may dis‐
1035 close information on when and what signatures are veri‐
1036 fied or to whom data is encrypted. This is similar to the
1037 "web bug" described for the auto-key-retrieve feature.
1038 pka-trust-increase
1041 Raise the trust in a signature to full if the signature
1042 passes PKA validation. This option is only meaningful if
1043 pka-lookups is set.
1044 --enable-dsa2
1047 --disable-dsa2
1049 Enable hash truncation for all DSA keys even for old DSA Keys up
1050 to 1024 bit. This is also the default with --openpgp. Note
1051 that older versions of GnuPG also required this flag to allow
1052 the generation of DSA larger than 1024 bit.
1053 --photo-viewer string
1056 This is the command line that should be run to view a photo ID.
1057 "%i" will be expanded to a filename containing the photo. "%I"
1058 does the same, except the file will not be deleted once the
1059 viewer exits. Other flags are "%k" for the key ID, "%K" for the
1060 long key ID, "%f" for the key fingerprint, "%t" for the exten‐
1061 sion of the image type (e.g. "jpg"), "%T" for the MIME type of
1062 the image (e.g. "image/jpeg"), and "%%" for an actual percent
1063 sign. If neither %i or %I are present, then the photo will be
1064 supplied to the viewer on standard input.
1065 The default viewer is "xloadimage -fork -quiet -title 'KeyID
1067 0x%k' STDIN". Note that if your image viewer program is not
1068 secure, then executing it from GnuPG does not make it secure.
1069 --exec-path string
1072 Sets a list of directories to search for photo viewers and key‐
1073 server helpers. If not provided, keyserver helpers use the com‐
1074 piled-in default directory, and photo viewers use the $PATH
1075 environment variable. Note, that on W32 system this value is
1076 ignored when searching for keyserver helpers.
1077 --keyring file
1080 Add file to the current list of keyrings. If file begins with a
1081 tilde and a slash, these are replaced by the $HOME directory. If
1082 the filename does not contain a slash, it is assumed to be in
1083 the GnuPG home directory ("~/.gnupg" if --homedir or $GNUPGHOME
1084 is not used).
1085 Note that this adds a keyring to the current list. If the intent
1087 is to use the specified keyring alone, use --keyring along with
1088 --no-default-keyring.
1089 --secret-keyring file
1092 Same as --keyring but for the secret keyrings.
1093 --primary-keyring file
1096 Designate file as the primary public keyring. This means that
1097 newly imported keys (via --import or keyserver --recv-from) will
1098 go to this keyring.
1099 --trustdb-name file
1102 Use file instead of the default trustdb. If file begins with a
1103 tilde and a slash, these are replaced by the $HOME directory. If
1104 the filename does not contain a slash, it is assumed to be in
1105 the GnuPG home directory (‘~/.gnupg’ if --homedir or $GNUPGHOME
1106 is not used).
1107 --homedir dir
1110 Set the name of the home directory to dir. If this option is not
1111 used, the home directory defaults to ‘~/.gnupg’. It is only
1112 recognized when given on the command line. It also overrides
1113 any home directory stated through the environment variable
1114 ‘GNUPGHOME’ or (on W32 systems) by means of the Registry entry
1115 HKCU\Software\GNU\GnuPG:HomeDir.
1116 --display-charset name
1124 Set the name of the native character set. This is used to con‐
1125 vert some informational strings like user IDs to the proper
1126 UTF-8 encoding. Note that this has nothing to do with the char‐
1127 acter set of data to be encrypted or signed; GnuPG does not
1128 recode user-supplied data. If this option is not used, the
1129 default character set is determined from the current locale. A
1130 verbosity level of 3 shows the chosen set. Valid values for
1131 name are:
1132 iso-8859-1
1136 This is the Latin 1 set.
1137 iso-8859-2
1140 The Latin 2 set.
1141 iso-8859-15
1144 This is currently an alias for the Latin 1 set.
1145 koi8-r The usual Russian set (rfc1489).
1148 utf-8 Bypass all translations and assume that the OS uses
1151 native UTF-8 encoding.
1152 --utf8-strings
1155 --no-utf8-strings
1157 Assume that command line arguments are given as UTF8 strings.
1158 The default (--no-utf8-strings) is to assume that arguments are
1159 encoded in the character set as specified by --display-charset.
1160 These options affect all following arguments. Both options may
1161 be used multiple times.
1162 --options file
1165 Read options from file and do not try to read them from the
1166 default options file in the homedir (see --homedir). This option
1167 is ignored if used in an options file.
1168 --no-options
1171 Shortcut for --options /dev/null. This option is detected before
1172 an attempt to open an option file. Using this option will also
1173 prevent the creation of a ‘~/.gnupg’ homedir.
1174 -z n
1179 --compress-level n
1181 --bzip2-compress-level n
1183 Set compression level to n for the ZIP and ZLIB compression
1184 algorithms. The default is to use the default compression level
1185 of zlib (normally 6). --bzip2-compress-level sets the compres‐
1186 sion level for the BZIP2 compression algorithm (defaulting to 6
1187 as well). This is a different option from --compress-level since
1188 BZIP2 uses a significant amount of memory for each additional
1189 compression level. -z sets both. A value of 0 for n disables
1190 compression.
1191 --bzip2-decompress-lowmem
1194 Use a different decompression method for BZIP2 compressed files.
1195 This alternate method uses a bit more than half the memory, but
1196 also runs at half the speed. This is useful under extreme low
1197 memory circumstances when the file was originally compressed at
1198 a high --bzip2-compress-level.
1199 --mangle-dos-filenames
1203 --no-mangle-dos-filenames
1205 Older version of Windows cannot handle filenames with more than
1206 one dot. --mangle-dos-filenames causes GnuPG to replace (rather
1207 than add to) the extension of an output filename to avoid this
1208 problem. This option is off by default and has no effect on non-
1209 Windows platforms.
1210 --ask-cert-level
1213 --no-ask-cert-level
1215 When making a key signature, prompt for a certification level.
1216 If this option is not specified, the certification level used is
1217 set via --default-cert-level. See --default-cert-level for
1218 information on the specific levels and how they are used. --no-
1219 ask-cert-level disables this option. This option defaults to no.
1220 --default-cert-level n
1223 The default to use for the check level when signing a key.
1224 0 means you make no particular claim as to how carefully you
1226 verified the key.
1227 1 means you believe the key is owned by the person who claims to
1229 own it but you could not, or did not verify the key at all. This
1230 is useful for a "persona" verification, where you sign the key
1231 of a pseudonymous user.
1232 2 means you did casual verification of the key. For example,
1234 this could mean that you verified that the key fingerprint and
1235 checked the user ID on the key against a photo ID.
1236 3 means you did extensive verification of the key. For example,
1238 this could mean that you verified the key fingerprint with the
1239 owner of the key in person, and that you checked, by means of a
1240 hard to forge document with a photo ID (such as a passport) that
1241 the name of the key owner matches the name in the user ID on the
1242 key, and finally that you verified (by exchange of email) that
1243 the email address on the key belongs to the key owner.
1244 Note that the examples given above for levels 2 and 3 are just
1246 that: examples. In the end, it is up to you to decide just what
1247 "casual" and "extensive" mean to you.
1248 This option defaults to 0 (no particular claim).
1250 --min-cert-level
1253 When building the trust database, treat any signatures with a
1254 certification level below this as invalid. Defaults to 2, which
1255 disregards level 1 signatures. Note that level 0 "no particular
1256 claim" signatures are always accepted.
1257 --trusted-key long key ID
1260 Assume that the specified key (which must be given as a full 8
1261 byte key ID) is as trustworthy as one of your own secret keys.
1262 This option is useful if you don't want to keep your secret keys
1263 (or one of them) online but still want to be able to check the
1264 validity of a given recipient's or signator's key.
1265 --trust-model pgp|classic|direct|always|auto
1268 Set what trust model GnuPG should follow. The models are:
1269 pgp This is the Web of Trust combined with trust signatures
1273 as used in PGP 5.x and later. This is the default trust
1274 model when creating a new trust database.
1275 classic
1278 This is the standard Web of Trust as used in PGP 2.x and
1279 earlier.
1280 direct Key validity is set directly by the user and not calcu‐
1283 lated via the Web of Trust.
1284 always Skip key validation and assume that used keys are always
1287 fully trusted. You generally won't use this unless you
1288 are using some external validation scheme. This option
1289 also suppresses the "[uncertain]" tag printed with signa‐
1290 ture checks when there is no evidence that the user ID is
1291 bound to the key.
1292 auto Select the trust model depending on whatever the internal
1295 trust database says. This is the default model if such a
1296 database already exists.
1297 --auto-key-locate parameters
1300 --no-auto-key-locate
1302 GnuPG can automatically locate and retrieve keys as needed using
1303 this option. This happens when encrypting to an email address
1304 (in the "user@example.com" form), and there are no user@exam‐
1305 ple.com keys on the local keyring. This option takes any number
1306 of the following mechanisms, in the order they are to be tried:
1307 cert Locate a key using DNS CERT, as specified in rfc4398.
1311 pka Locate a key using DNS PKA.
1314 ldap Using DNS Service Discovery, check the domain in question
1317 for any LDAP keyservers to use. If this fails, attempt
1318 to locate the key using the PGP Universal method of
1319 checking 'ldap://keys.(thedomain)'.
1320 keyserver
1323 Locate a key using whatever keyserver is defined using
1324 the --keyserver option.
1325 keyserver-URL
1328 In addition, a keyserver URL as used in the --keyserver
1329 option may be used here to query that particular key‐
1330 server.
1331 local Locate the key using the local keyrings. This mechanism
1334 allows to select the order a local key lookup is done.
1335 Thus using '--auto-key-locate local' is identical to
1336 --no-auto-key-locate.
1337 nodefault
1340 This flag disables the standard local key lookup, done
1341 before any of the mechanisms defined by the --auto-key-
1342 locate are tried. The position of this mechanism in the
1343 list does not matter. It is not required if local is
1344 also used.
1345 --keyid-format short|0xshort|long|0xlong
1349 Select how to display key IDs. "short" is the traditional
1350 8-character key ID. "long" is the more accurate (but less conve‐
1351 nient) 16-character key ID. Add an "0x" to either to include an
1352 "0x" at the beginning of the key ID, as in 0x99242560.
1353 --keyserver name
1356 Use name as your keyserver. This is the server that --recv-keys,
1357 --send-keys, and --search-keys will communicate with to receive
1358 keys from, send keys to, and search for keys on. The format of
1359 the name is a URI: `scheme:[//]keyservername[:port]' The scheme
1360 is the type of keyserver: "hkp" for the HTTP (or compatible)
1361 keyservers, "ldap" for the LDAP keyservers, or "mailto" for the
1362 Graff email keyserver. Note that your particular installation of
1363 GnuPG may have other keyserver types available as well. Key‐
1364 server schemes are case-insensitive. After the keyserver name,
1365 optional keyserver configuration options may be provided. These
1366 are the same as the global --keyserver-options from below, but
1367 apply only to this particular keyserver.
1368 Most keyservers synchronize with each other, so there is gener‐
1370 ally no need to send keys to more than one server. The keyserver
1371 hkp://keys.gnupg.net uses round robin DNS to give a different
1372 keyserver each time you use it.
1373 --keyserver-options name=value1
1376 This is a space or comma delimited string that gives options for
1377 the keyserver. Options can be prefixed with a `no-' to give the
1378 opposite meaning. Valid import-options or export-options may be
1379 used here as well to apply to importing (--recv-key) or export‐
1380 ing (--send-key) a key from a keyserver. While not all options
1381 are available for all keyserver types, some common options are:
1382 include-revoked
1386 When searching for a key with --search-keys, include keys
1387 that are marked on the keyserver as revoked. Note that
1388 not all keyservers differentiate between revoked and
1389 unrevoked keys, and for such keyservers this option is
1390 meaningless. Note also that most keyservers do not have
1391 cryptographic verification of key revocations, and so
1392 turning this option off may result in skipping keys that
1393 are incorrectly marked as revoked.
1394 include-disabled
1397 When searching for a key with --search-keys, include keys
1398 that are marked on the keyserver as disabled. Note that
1399 this option is not used with HKP keyservers.
1400 auto-key-retrieve
1403 This option enables the automatic retrieving of keys from
1404 a keyserver when verifying signatures made by keys that
1405 are not on the local keyring.
1406 Note that this option makes a "web bug" like behavior
1408 possible. Keyserver operators can see which keys you
1409 request, so by sending you a message signed by a brand
1410 new key (which you naturally will not have on your local
1411 keyring), the operator can tell both your IP address and
1412 the time when you verified the signature.
1413 honor-keyserver-url
1416 When using --refresh-keys, if the key in question has a
1417 preferred keyserver URL, then use that preferred key‐
1418 server to refresh the key from. In addition, if auto-key-
1419 retrieve is set, and the signature being verified has a
1420 preferred keyserver URL, then use that preferred key‐
1421 server to fetch the key from. Defaults to yes.
1422 honor-pka-record
1425 If auto-key-retrieve is set, and the signature being ver‐
1426 ified has a PKA record, then use the PKA information to
1427 fetch the key. Defaults to yes.
1428 include-subkeys
1431 When receiving a key, include subkeys as potential tar‐
1432 gets. Note that this option is not used with HKP key‐
1433 servers, as they do not support retrieving keys by subkey
1434 id.
1435 use-temp-files
1438 On most Unix-like platforms, GnuPG communicates with the
1439 keyserver helper program via pipes, which is the most
1440 efficient method. This option forces GnuPG to use tempo‐
1441 rary files to communicate. On some platforms (such as
1442 Win32 and RISC OS), this option is always enabled.
1443 keep-temp-files
1446 If using `use-temp-files', do not delete the temp files
1447 after using them. This option is useful to learn the key‐
1448 server communication protocol by reading the temporary
1449 files.
1450 verbose
1453 Tell the keyserver helper program to be more verbose.
1454 This option can be repeated multiple times to increase
1455 the verbosity level.
1456 timeout
1459 Tell the keyserver helper program how long (in seconds)
1460 to try and perform a keyserver action before giving up.
1461 Note that performing multiple actions at the same time
1462 uses this timeout value per action. For example, when
1463 retrieving multiple keys via --recv-keys, the timeout
1464 applies separately to each key retrieval, and not to the
1465 --recv-keys command as a whole. Defaults to 30 seconds.
1466 http-proxy=value
1469 Set the proxy to use for HTTP and HKP keyservers. This
1470 overrides the "http_proxy" environment variable, if any.
1471 max-cert-size
1474 When retrieving a key via DNS CERT, only accept keys up
1475 to this size. Defaults to 16384 bytes.
1476 debug Turn on debug output in the keyserver helper program.
1479 Note that the details of debug output depends on which
1480 keyserver helper program is being used, and in turn, on
1481 any libraries that the keyserver helper program uses
1482 internally (libcurl, openldap, etc).
1483 check-cert
1486 Enable certificate checking if the keyserver presents one
1487 (for hkps or ldaps). Defaults to on.
1488 ca-cert-file
1491 Provide a certificate file to override the system
1492 default. Only necessary if check-cert is enabled, and
1493 the keyserver is using a certificate that is not present
1494 in a system default certificate list.
1495 --completes-needed n
1499 Number of completely trusted users to introduce a new key signer
1500 (defaults to 1).
1501 --marginals-needed n
1504 Number of marginally trusted users to introduce a new key signer
1505 (defaults to 3)
1506 --max-cert-depth n
1509 Maximum depth of a certification chain (default is 5).
1510 --simple-sk-checksum
1513 Secret keys are integrity protected by using a SHA-1 checksum.
1514 This method is part of the upcoming enhanced OpenPGP specifica‐
1515 tion but GnuPG already uses it as a countermeasure against cer‐
1516 tain attacks. Old applications don't understand this new for‐
1517 mat, so this option may be used to switch back to the old behav‐
1518 iour. Using this option bears a security risk. Note that using
1519 this option only takes effect when the secret key is encrypted -
1520 the simplest way to make this happen is to change the passphrase
1521 on the key (even changing it to the same value is acceptable).
1522 --no-sig-cache
1525 Do not cache the verification status of key signatures. Caching
1526 gives a much better performance in key listings. However, if you
1527 suspect that your public keyring is not save against write modi‐
1528 fications, you can use this option to disable the caching. It
1529 probably does not make sense to disable it because all kind of
1530 damage can be done if someone else has write access to your pub‐
1531 lic keyring.
1532 --no-sig-create-check
1535 GnuPG normally verifies each signature right after creation to
1536 protect against bugs and hardware malfunctions which could leak
1537 out bits from the secret key. This extra verification needs some
1538 time (about 115% for DSA keys), and so this option can be used
1539 to disable it. However, due to the fact that the signature cre‐
1540 ation needs manual interaction, this performance penalty does
1541 not matter in most settings.
1542 --auto-check-trustdb
1545 --no-auto-check-trustdb
1547 If GnuPG feels that its information about the Web of Trust has
1548 to be updated, it automatically runs the --check-trustdb command
1549 internally. This may be a time consuming process. --no-auto-
1550 check-trustdb disables this option.
1551 --use-agent
1554 --no-use-agent
1556 This is dummy option. gpg2 always requires the agent.
1557 --gpg-agent-info
1560 This is dummy option. It has no effect when used with gpg2.
1561 --lock-once
1564 Lock the databases the first time a lock is requested and do not
1565 release the lock until the process terminates.
1566 --lock-multiple
1569 Release the locks every time a lock is no longer needed. Use
1570 this to override a previous --lock-once from a config file.
1571 --lock-never
1574 Disable locking entirely. This option should be used only in
1575 very special environments, where it can be assured that only one
1576 process is accessing those files. A bootable floppy with a
1577 stand-alone encryption system will probably use this. Improper
1578 usage of this option may lead to data and key corruption.
1579 --exit-on-status-write-error
1582 This option will cause write errors on the status FD to immedi‐
1583 ately terminate the process. That should in fact be the default
1584 but it never worked this way and thus we need an option to
1585 enable this, so that the change won't break applications which
1586 close their end of a status fd connected pipe too early. Using
1587 this option along with --enable-progress-filter may be used to
1588 cleanly cancel long running gpg operations.
1589 --limit-card-insert-tries n
1592 With n greater than 0 the number of prompts asking to insert a
1593 smartcard gets limited to N-1. Thus with a value of 1 gpg won't
1594 at all ask to insert a card if none has been inserted at
1595 startup. This option is useful in the configuration file in case
1596 an application does not know about the smartcard support and
1597 waits ad infinitum for an inserted card.
1598 --no-random-seed-file
1601 GnuPG uses a file to store its internal random pool over invoca‐
1602 tions. This makes random generation faster; however sometimes
1603 write operations are not desired. This option can be used to
1604 achieve that with the cost of slower random generation.
1605 --no-greeting
1608 Suppress the initial copyright message.
1609 --no-secmem-warning
1612 Suppress the warning about "using insecure memory".
1613 --no-permission-warning
1616 Suppress the warning about unsafe file and home directory
1617 (--homedir) permissions. Note that the permission checks that
1618 GnuPG performs are not intended to be authoritative, but rather
1619 they simply warn about certain common permission problems. Do
1620 not assume that the lack of a warning means that your system is
1621 secure.
1622 Note that the warning for unsafe --homedir permissions cannot be
1624 suppressed in the gpg.conf file, as this would allow an attacker
1625 to place an unsafe gpg.conf file in place, and use this file to
1626 suppress warnings about itself. The --homedir permissions warn‐
1627 ing may only be suppressed on the command line.
1628 --no-mdc-warning
1631 Suppress the warning about missing MDC integrity protection.
1632 --require-secmem
1635 --no-require-secmem
1637 Refuse to run if GnuPG cannot get secure memory. Defaults to no
1638 (i.e. run, but give a warning).
1639 --require-cross-certification
1643 --no-require-cross-certification
1645 When verifying a signature made from a subkey, ensure that the
1646 cross certification "back signature" on the subkey is present
1647 and valid. This protects against a subtle attack against sub‐
1648 keys that can sign. Defaults to --require-cross-certification
1649 for gpg2.
1650 --expert
1653 --no-expert
1655 Allow the user to do certain nonsensical or "silly" things like
1656 signing an expired or revoked key, or certain potentially incom‐
1657 patible things like generating unusual key types. This also dis‐
1658 ables certain warning messages about potentially incompatible
1659 actions. As the name implies, this option is for experts only.
1660 If you don't fully understand the implications of what it allows
1661 you to do, leave this off. --no-expert disables this option.
1662 Key related options
1671 --recipient name
1676 -r Encrypt for user id name. If this option or --hidden-recipient
1678 is not specified, GnuPG asks for the user-id unless --default-
1679 recipient is given.
1680 --hidden-recipient name
1683 -R Encrypt for user ID name, but hide the key ID of this user's
1685 key. This option helps to hide the receiver of the message and
1686 is a limited countermeasure against traffic analysis. If this
1687 option or --recipient is not specified, GnuPG asks for the user
1688 ID unless --default-recipient is given.
1689 --encrypt-to name
1692 Same as --recipient but this one is intended for use in the
1693 options file and may be used with your own user-id as an
1694 "encrypt-to-self". These keys are only used when there are other
1695 recipients given either by use of --recipient or by the asked
1696 user id. No trust checking is performed for these user ids and
1697 even disabled keys can be used.
1698 --hidden-encrypt-to name
1701 Same as --hidden-recipient but this one is intended for use in
1702 the options file and may be used with your own user-id as a hid‐
1703 den "encrypt-to-self". These keys are only used when there are
1704 other recipients given either by use of --recipient or by the
1705 asked user id. No trust checking is performed for these user
1706 ids and even disabled keys can be used.
1707 --no-encrypt-to
1710 Disable the use of all --encrypt-to and --hidden-encrypt-to
1711 keys.
1712 --group name=value1
1715 Sets up a named group, which is similar to aliases in email pro‐
1716 grams. Any time the group name is a recipient (-r or --recipi‐
1717 ent), it will be expanded to the values specified. Multiple
1718 groups with the same name are automatically merged into a single
1719 group.
1720 The values are key IDs or fingerprints, but any key description
1722 is accepted. Note that a value with spaces in it will be treated
1723 as two different values. Note also there is only one level of
1724 expansion --- you cannot make an group that points to another
1725 group. When used from the command line, it may be necessary to
1726 quote the argument to this option to prevent the shell from
1727 treating it as multiple arguments.
1728 --ungroup name
1731 Remove a given entry from the --group list.
1732 --no-groups
1735 Remove all entries from the --group list.
1736 --local-user name
1739 -u Use name as the key to sign with. Note that this option over‐
1741 rides --default-key.
1742 --try-all-secrets
1745 Don't look at the key ID as stored in the message but try all
1746 secret keys in turn to find the right decryption key. This
1747 option forces the behaviour as used by anonymous recipients
1748 (created by using --throw-keyids) and might come handy in case
1749 where an encrypted message contains a bogus key ID.
1750 Input and Output
1759 --armor
1764 -a Create ASCII armored output. The default is to create the
1766 binary OpenPGP format.
1767 --no-armor
1770 Assume the input data is not in ASCII armored format.
1771 --output file
1774 -o file
1776 Write output to file.
1777 --max-output n
1780 This option sets a limit on the number of bytes that will be
1781 generated when processing a file. Since OpenPGP supports various
1782 levels of compression, it is possible that the plaintext of a
1783 given message may be significantly larger than the original
1784 OpenPGP message. While GnuPG works properly with such messages,
1785 there is often a desire to set a maximum file size that will be
1786 generated before processing is forced to stop by the OS limits.
1787 Defaults to 0, which means "no limit".
1788 --import-options parameters
1791 This is a space or comma delimited string that gives options for
1792 importing keys. Options can be prepended with a `no-' to give
1793 the opposite meaning. The options are:
1794 import-local-sigs
1798 Allow importing key signatures marked as "local". This is
1799 not generally useful unless a shared keyring scheme is
1800 being used. Defaults to no.
1801 repair-pks-subkey-bug
1804 During import, attempt to repair the damage caused by the
1805 PKS keyserver bug (pre version 0.9.6) that mangles keys
1806 with multiple subkeys. Note that this cannot completely
1807 repair the damaged key as some crucial data is removed by
1808 the keyserver, but it does at least give you back one
1809 subkey. Defaults to no for regular --import and to yes
1810 for keyserver --recv-keys.
1811 merge-only
1814 During import, allow key updates to existing keys, but do
1815 not allow any new keys to be imported. Defaults to no.
1816 import-clean
1819 After import, compact (remove all signatures except the
1820 self-signature) any user IDs from the new key that are
1821 not usable. Then, remove any signatures from the new key
1822 that are not usable. This includes signatures that were
1823 issued by keys that are not present on the keyring. This
1824 option is the same as running the --edit-key command
1825 "clean" after import. Defaults to no.
1826 import-minimal
1829 Import the smallest key possible. This removes all signa‐
1830 tures except the most recent self-signature on each user
1831 ID. This option is the same as running the --edit-key
1832 command "minimize" after import. Defaults to no.
1833 --export-options parameters
1836 This is a space or comma delimited string that gives options for
1837 exporting keys. Options can be prepended with a `no-' to give
1838 the opposite meaning. The options are:
1839 export-local-sigs
1843 Allow exporting key signatures marked as "local". This is
1844 not generally useful unless a shared keyring scheme is
1845 being used. Defaults to no.
1846 export-attributes
1849 Include attribute user IDs (photo IDs) while exporting.
1850 This is useful to export keys if they are going to be
1851 used by an OpenPGP program that does not accept attribute
1852 user IDs. Defaults to yes.
1853 export-sensitive-revkeys
1856 Include designated revoker information that was marked as
1857 "sensitive". Defaults to no.
1858 export-reset-subkey-passwd
1861 When using the --export-secret-subkeys command, this
1862 option resets the passphrases for all exported subkeys to
1863 empty. This is useful when the exported subkey is to be
1864 used on an unattended machine where a passphrase doesn't
1865 necessarily make sense. Defaults to no.
1866 export-clean
1869 Compact (remove all signatures from) user IDs on the key
1870 being exported if the user IDs are not usable. Also, do
1871 not export any signatures that are not usable. This
1872 includes signatures that were issued by keys that are not
1873 present on the keyring. This option is the same as run‐
1874 ning the --edit-key command "clean" before export except
1875 that the local copy of the key is not modified. Defaults
1876 to no.
1877 export-minimal
1880 Export the smallest key possible. This removes all signa‐
1881 tures except the most recent self-signature on each user
1882 ID. This option is the same as running the --edit-key
1883 command "minimize" before export except that the local
1884 copy of the key is not modified. Defaults to no.
1885 --with-colons
1888 Print key listings delimited by colons. Note that the output
1889 will be encoded in UTF-8 regardless of any --display-charset
1890 setting. This format is useful when GnuPG is called from scripts
1891 and other programs as it is easily machine parsed. The details
1892 of this format are documented in the file ‘doc/DETAILS’, which
1893 is included in the GnuPG source distribution.
1894 --fixed-list-mode
1897 Do not merge primary user ID and primary key in --with-colon
1898 listing mode and print all timestamps as seconds since
1899 1970-01-01. Since GnuPG 2.0.10, this mode is always used and
1900 thus this option is obsolete; it does not harm to use it though.
1901 --with-fingerprint
1904 Same as the command --fingerprint but changes only the format of
1905 the output and may be used together with another command.
1906 OpenPGP protocol specific options.
1912 -t, --textmode
1917 --no-textmode
1919 Treat input files as text and store them in the OpenPGP canoni‐
1920 cal text form with standard "CRLF" line endings. This also sets
1921 the necessary flags to inform the recipient that the encrypted
1922 or signed data is text and may need its line endings converted
1923 back to whatever the local system uses. This option is useful
1924 when communicating between two platforms that have different
1925 line ending conventions (UNIX-like to Mac, Mac to Windows, etc).
1926 --no-textmode disables this option, and is the default.
1927 --force-v3-sigs
1931 --no-force-v3-sigs
1933 OpenPGP states that an implementation should generate v4 signa‐
1934 tures but PGP versions 5 through 7 only recognize v4 signatures
1935 on key material. This option forces v3 signatures for signatures
1936 on data. Note that this option implies --ask-sig-expire, --sig-
1937 policy-url, --sig-notation, and --sig-keyserver-url, as these
1938 features cannot be used with v3 signatures. --no-force-v3-sigs
1939 disables this option.
1940 --force-v4-certs
1943 --no-force-v4-certs
1945 Always use v4 key signatures even on v3 keys. This option also
1946 changes the default hash algorithm for v3 RSA keys from MD5 to
1947 SHA-1. --no-force-v4-certs disables this option.
1948 --force-mdc
1951 Force the use of encryption with a modification detection code.
1952 This is always used with the newer ciphers (those with a block‐
1953 size greater than 64 bits), or if all of the recipient keys
1954 indicate MDC support in their feature flags.
1955 --disable-mdc
1958 Disable the use of the modification detection code. Note that by
1959 using this option, the encrypted message becomes vulnerable to a
1960 message modification attack.
1961 --personal-cipher-preferences string
1964 Set the list of personal cipher preferences to string. Use gpg2
1965 --version to get a list of available algorithms, and use none to
1966 set no preference at all. This allows the user to safely over‐
1967 ride the algorithm chosen by the recipient key preferences, as
1968 GPG will only select an algorithm that is usable by all recipi‐
1969 ents. The most highly ranked cipher in this list is also used
1970 for the --symmetric encryption command.
1971 --personal-digest-preferences string
1974 Set the list of personal digest preferences to string. Use gpg2
1975 --version to get a list of available algorithms, and use none to
1976 set no preference at all. This allows the user to safely over‐
1977 ride the algorithm chosen by the recipient key preferences, as
1978 GPG will only select an algorithm that is usable by all recipi‐
1979 ents. The most highly ranked digest algorithm in this list is
1980 also used when signing without encryption (e.g. --clearsign or
1981 --sign). The default value is SHA-1.
1982 --personal-compress-preferences string
1985 Set the list of personal compression preferences to string. Use
1986 gpg2 --version to get a list of available algorithms, and use
1987 none to set no preference at all. This allows the user to
1988 safely override the algorithm chosen by the recipient key pref‐
1989 erences, as GPG will only select an algorithm that is usable by
1990 all recipients. The most highly ranked compression algorithm in
1991 this list is also used when there are no recipient keys to con‐
1992 sider (e.g. --symmetric).
1993 --s2k-cipher-algo name
1996 Use name as the cipher algorithm used to protect secret keys.
1997 The default cipher is CAST5. This cipher is also used for con‐
1998 ventional encryption if --personal-cipher-preferences and
1999 --cipher-algo is not given.
2000 --s2k-digest-algo name
2003 Use name as the digest algorithm used to mangle the passphrases.
2004 The default algorithm is SHA-1.
2005 --s2k-mode n
2008 Selects how passphrases are mangled. If n is 0 a plain
2009 passphrase (which is not recommended) will be used, a 1 adds a
2010 salt to the passphrase and a 3 (the default) iterates the whole
2011 process a number of times (see --s2k-count). Unless --rfc1991
2012 is used, this mode is also used for conventional encryption.
2013 --s2k-count n
2016 Specify how many times the passphrase mangling is repeated.
2017 This value may range between 1024 and 65011712 inclusive, and
2018 the default is 65536. Note that not all values in the
2019 1024-65011712 range are legal and if an illegal value is
2020 selected, GnuPG will round up to the nearest legal value. This
2021 option is only meaningful if --s2k-mode is 3.
2022 Compliance options
2028 These options control what GnuPG is compliant to. Only one of these
2031 options may be active at a time. Note that the default setting of this
2032 is nearly always the correct one. See the INTEROPERABILITY WITH OTHER
2033 OPENPGP PROGRAMS section below before using one of these options.
2034 --gnupg
2038 Use standard GnuPG behavior. This is essentially OpenPGP behav‐
2039 ior (see --openpgp), but with some additional workarounds for
2040 common compatibility problems in different versions of PGP. This
2041 is the default option, so it is not generally needed, but it may
2042 be useful to override a different compliance option in the
2043 gpg.conf file.
2044 --openpgp
2047 Reset all packet, cipher and digest options to strict OpenPGP
2048 behavior. Use this option to reset all previous options like
2049 --s2k-*, --cipher-algo, --digest-algo and --compress-algo to
2050 OpenPGP compliant values. All PGP workarounds are disabled.
2051 --rfc4880
2054 Reset all packet, cipher and digest options to strict RFC-4880
2055 behavior. Note that this is currently the same thing as
2056 --openpgp.
2057 --rfc2440
2060 Reset all packet, cipher and digest options to strict RFC-2440
2061 behavior.
2062 --rfc1991
2065 Try to be more RFC-1991 (PGP 2.x) compliant.
2066 --pgp2 Set up all options to be as PGP 2.x compliant as possible, and
2069 warn if an action is taken (e.g. encrypting to a non-RSA key)
2070 that will create a message that PGP 2.x will not be able to han‐
2071 dle. Note that `PGP 2.x' here means `MIT PGP 2.6.2'. There are
2072 other versions of PGP 2.x available, but the MIT release is a
2073 good common baseline.
2074 This option implies --rfc1991 --disable-mdc --no-force-v4-certs
2076 --escape-from-lines --force-v3-sigs --cipher-algo IDEA --digest-
2077 algo MD5 --compress-algo ZIP. It also disables --textmode when
2078 encrypting.
2079 --pgp6 Set up all options to be as PGP 6 compliant as possible. This
2082 restricts you to the ciphers IDEA (if the IDEA plugin is
2083 installed), 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160,
2084 and the compression algorithms none and ZIP. This also disables
2085 --throw-keyids, and making signatures with signing subkeys as
2086 PGP 6 does not understand signatures made by signing subkeys.
2087 This option implies --disable-mdc --escape-from-lines --force-
2089 v3-sigs.
2090 --pgp7 Set up all options to be as PGP 7 compliant as possible. This is
2093 identical to --pgp6 except that MDCs are not disabled, and the
2094 list of allowable ciphers is expanded to add AES128, AES192,
2095 AES256, and TWOFISH.
2096 --pgp8 Set up all options to be as PGP 8 compliant as possible. PGP 8
2099 is a lot closer to the OpenPGP standard than previous versions
2100 of PGP, so all this does is disable --throw-keyids and set
2101 --escape-from-lines. All algorithms are allowed except for the
2102 SHA224, SHA384, and SHA512 digests.
2103 Doing things one usually doesn't want to do.
2109 -n
2114 --dry-run
2116 Don't make any changes (this is not completely implemented).
2117 --list-only
2120 Changes the behaviour of some commands. This is like --dry-run
2121 but different in some cases. The semantic of this command may be
2122 extended in the future. Currently it only skips the actual
2123 decryption pass and therefore enables a fast listing of the
2124 encryption keys.
2125 -i
2128 --interactive
2130 Prompt before overwriting any files.
2131 --debug-level level
2134 Select the debug level for investigating problems. level may be
2135 a numeric value or by a keyword:
2136 none No debugging at all. A value of less than 1 may be used
2139 instead of the keyword.
2140 basic Some basic debug messages. A value between 1 and 2 may
2142 be used instead of the keyword.
2143 advanced
2145 More verbose debug messages. A value between 3 and 5 may
2146 be used instead of the keyword.
2147 expert Even more detailed messages. A value between 6 and 8 may
2149 be used instead of the keyword.
2150 guru All of the debug messages you can get. A value greater
2152 than 8 may be used instead of the keyword. The creation
2153 of hash tracing files is only enabled if the keyword is
2154 used.
2155 How these messages are mapped to the actual debugging flags is not
2157 specified and may change with newer releases of this program. They are
2158 however carefully selected to best aid in debugging.
2159 --debug flags
2162 Set debugging flags. All flags are or-ed and flags may be given
2163 in C syntax (e.g. 0x0042).
2164 --debug-all
2167 Set all useful debugging flags.
2168 --enable-progress-filter
2172 Enable certain PROGRESS status outputs. This option allows fron‐
2173 tends to display a progress indicator while gpg is processing
2174 larger files. There is a slight performance overhead using it.
2175 --status-fd n
2178 Write special status strings to the file descriptor n. See the
2179 file DETAILS in the documentation for a listing of them.
2180 --status-file file
2183 Same as --status-fd, except the status data is written to file
2184 file.
2185 --logger-fd n
2188 Write log output to file descriptor n and not to STDERR.
2189 --log-file file
2192 --logger-file file
2194 Same as --logger-fd, except the logger data is written to file
2195 file. Note that --log-file is only implemented for GnuPG-2.
2196 --attribute-fd n
2199 Write attribute subpackets to the file descriptor n. This is
2200 most useful for use with --status-fd, since the status messages
2201 are needed to separate out the various subpackets from the
2202 stream delivered to the file descriptor.
2203 --attribute-file file
2206 Same as --attribute-fd, except the attribute data is written to
2207 file file.
2208 --comment string
2211 --no-comments
2213 Use string as a comment string in clear text signatures and
2214 ASCII armored messages or keys (see --armor). The default behav‐
2215 ior is not to use a comment string. --comment may be repeated
2216 multiple times to get multiple comment strings. --no-comments
2217 removes all comments. It is a good idea to keep the length of a
2218 single comment below 60 characters to avoid problems with mail
2219 programs wrapping such lines. Note that comment lines, like all
2220 other header lines, are not protected by the signature.
2221 --emit-version
2224 --no-emit-version
2226 Force inclusion of the version string in ASCII armored output.
2227 --no-emit-version disables this option.
2228 --sig-notation name=value
2231 --cert-notation name=value
2233 -N, --set-notation name=value
2235 Put the name value pair into the signature as notation data.
2236 name must consist only of printable characters or spaces, and
2237 must contain a '@' character in the form keyname@domain.exam‐
2238 ple.com (substituting the appropriate keyname and domain name,
2239 of course). This is to help prevent pollution of the IETF
2240 reserved notation namespace. The --expert flag overrides the '@'
2241 check. value may be any printable string; it will be encoded in
2242 UTF8, so you should check that your --display-charset is set
2243 correctly. If you prefix name with an exclamation mark (!), the
2244 notation data will be flagged as critical (rfc2440:5.2.3.15).
2245 --sig-notation sets a notation for data signatures. --cert-nota‐
2246 tion sets a notation for key signatures (certifications). --set-
2247 notation sets both.
2248 There are special codes that may be used in notation names. "%k"
2250 will be expanded into the key ID of the key being signed, "%K"
2251 into the long key ID of the key being signed, "%f" into the fin‐
2252 gerprint of the key being signed, "%s" into the key ID of the
2253 key making the signature, "%S" into the long key ID of the key
2254 making the signature, "%g" into the fingerprint of the key mak‐
2255 ing the signature (which might be a subkey), "%p" into the fin‐
2256 gerprint of the primary key of the key making the signature,
2257 "%c" into the signature count from the OpenPGP smartcard, and
2258 "%%" results in a single "%". %k, %K, and %f are only meaningful
2259 when making a key signature (certification), and %c is only
2260 meaningful when using the OpenPGP smartcard.
2261 --sig-policy-url string
2264 --cert-policy-url string
2266 --set-policy-url string
2268 Use string as a Policy URL for signatures (rfc2440:5.2.3.19).
2269 If you prefix it with an exclamation mark (!), the policy URL
2270 packet will be flagged as critical. --sig-policy-url sets a pol‐
2271 icy url for data signatures. --cert-policy-url sets a policy url
2272 for key signatures (certifications). --set-policy-url sets both.
2273 The same %-expandos used for notation data are available here as
2275 well.
2276 --sig-keyserver-url string
2279 Use string as a preferred keyserver URL for data signatures. If
2280 you prefix it with an exclamation mark (!), the keyserver URL
2281 packet will be flagged as critical.
2282 The same %-expandos used for notation data are available here as
2284 well.
2285 --set-filename string
2288 Use string as the filename which is stored inside messages.
2289 This overrides the default, which is to use the actual filename
2290 of the file being encrypted.
2291 --for-your-eyes-only
2294 --no-for-your-eyes-only
2296 Set the `for your eyes only' flag in the message. This causes
2297 GnuPG to refuse to save the file unless the --output option is
2298 given, and PGP to use a "secure viewer" with a claimed Tempest-
2299 resistant font to display the message. This option overrides
2300 --set-filename. --no-for-your-eyes-only disables this option.
2301 --use-embedded-filename
2304 --no-use-embedded-filename
2306 Try to create a file with a name as embedded in the data. This
2307 can be a dangerous option as it allows to overwrite files.
2308 Defaults to no.
2309 --cipher-algo name
2312 Use name as cipher algorithm. Running the program with the com‐
2313 mand --version yields a list of supported algorithms. If this is
2314 not used the cipher algorithm is selected from the preferences
2315 stored with the key. In general, you do not want to use this
2316 option as it allows you to violate the OpenPGP standard. --per‐
2317 sonal-cipher-preferences is the safe way to accomplish the same
2318 thing.
2319 --digest-algo name
2322 Use name as the message digest algorithm. Running the program
2323 with the command --version yields a list of supported algo‐
2324 rithms. In general, you do not want to use this option as it
2325 allows you to violate the OpenPGP standard. --personal-digest-
2326 preferences is the safe way to accomplish the same thing.
2327 --compress-algo name
2330 Use compression algorithm name. "zlib" is RFC-1950 ZLIB compres‐
2331 sion. "zip" is RFC-1951 ZIP compression which is used by PGP.
2332 "bzip2" is a more modern compression scheme that can compress
2333 some things better than zip or zlib, but at the cost of more
2334 memory used during compression and decompression. "uncompressed"
2335 or "none" disables compression. If this option is not used, the
2336 default behavior is to examine the recipient key preferences to
2337 see which algorithms the recipient supports. If all else fails,
2338 ZIP is used for maximum compatibility.
2339 ZLIB may give better compression results than ZIP, as the com‐
2341 pression window size is not limited to 8k. BZIP2 may give even
2342 better compression results than that, but will use a signifi‐
2343 cantly larger amount of memory while compressing and decompress‐
2344 ing. This may be significant in low memory situations. Note,
2345 however, that PGP (all versions) only supports ZIP compression.
2346 Using any algorithm other than ZIP or "none" will make the mes‐
2347 sage unreadable with PGP. In general, you do not want to use
2348 this option as it allows you to violate the OpenPGP standard.
2349 --personal-compress-preferences is the safe way to accomplish
2350 the same thing.
2351 --cert-digest-algo name
2354 Use name as the message digest algorithm used when signing a
2355 key. Running the program with the command --version yields a
2356 list of supported algorithms. Be aware that if you choose an
2357 algorithm that GnuPG supports but other OpenPGP implementations
2358 do not, then some users will not be able to use the key signa‐
2359 tures you make, or quite possibly your entire key.
2360 --disable-cipher-algo name
2363 Never allow the use of name as cipher algorithm. The given name
2364 will not be checked so that a later loaded algorithm will still
2365 get disabled.
2366 --disable-pubkey-algo name
2369 Never allow the use of name as public key algorithm. The given
2370 name will not be checked so that a later loaded algorithm will
2371 still get disabled.
2372 --throw-keyids
2375 --no-throw-keyids
2377 Do not put the recipient key IDs into encrypted messages. This
2378 helps to hide the receivers of the message and is a limited
2379 countermeasure against traffic analysis. ([Using a little social
2380 engineering anyone who is able to decrypt the message can check
2381 whether one of the other recipients is the one he suspects.])
2382 On the receiving side, it may slow down the decryption process
2383 because all available secret keys must be tried. --no-throw-
2384 keyids disables this option. This option is essentially the same
2385 as using --hidden-recipient for all recipients.
2386 --not-dash-escaped
2389 This option changes the behavior of cleartext signatures so that
2390 they can be used for patch files. You should not send such an
2391 armored file via email because all spaces and line endings are
2392 hashed too. You can not use this option for data which has 5
2393 dashes at the beginning of a line, patch files don't have this.
2394 A special armor header line tells GnuPG about this cleartext
2395 signature option.
2396 --escape-from-lines
2399 --no-escape-from-lines
2401 Because some mailers change lines starting with "From " to
2402 ">From " it is good to handle such lines in a special way when
2403 creating cleartext signatures to prevent the mail system from
2404 breaking the signature. Note that all other PGP versions do it
2405 this way too. Enabled by default. --no-escape-from-lines dis‐
2406 ables this option.
2407 --passphrase-repeat n
2410 Specify how many times gpg2 will request a new passphrase be
2411 repeated. This is useful for helping memorize a passphrase.
2412 Defaults to 1 repetition.
2413 --passphrase-fd n
2416 Read the passphrase from file descriptor n. Only the first line
2417 will be read from file descriptor n. If you use 0 for n, the
2418 passphrase will be read from STDIN. This can only be used if
2419 only one passphrase is supplied. Note that this passphrase is
2420 only used if the option --batch has also been given. This is
2421 different from gpg.
2422 --passphrase-file file
2425 Read the passphrase from file file. Only the first line will be
2426 read from file file. This can only be used if only one
2427 passphrase is supplied. Obviously, a passphrase stored in a file
2428 is of questionable security if other users can read this file.
2429 Don't use this option if you can avoid it. Note that this
2430 passphrase is only used if the option --batch has also been
2431 given. This is different from gpg.
2432 --passphrase string
2435 Use string as the passphrase. This can only be used if only one
2436 passphrase is supplied. Obviously, this is of very questionable
2437 security on a multi-user system. Don't use this option if you
2438 can avoid it. Note that this passphrase is only used if the
2439 option --batch has also been given. This is different from gpg.
2440 --command-fd n
2443 This is a replacement for the deprecated shared-memory IPC mode.
2444 If this option is enabled, user input on questions is not
2445 expected from the TTY but from the given file descriptor. It
2446 should be used together with --status-fd. See the file
2447 doc/DETAILS in the source distribution for details on how to use
2448 it.
2449 --command-file file
2452 Same as --command-fd, except the commands are read out of file
2453 file
2454 --allow-non-selfsigned-uid
2457 --no-allow-non-selfsigned-uid
2459 Allow the import and use of keys with user IDs which are not
2460 self-signed. This is not recommended, as a non self-signed user
2461 ID is trivial to forge. --no-allow-non-selfsigned-uid disables.
2462 --allow-freeform-uid
2465 Disable all checks on the form of the user ID while generating a
2466 new one. This option should only be used in very special envi‐
2467 ronments as it does not ensure the de-facto standard format of
2468 user IDs.
2469 --ignore-time-conflict
2472 GnuPG normally checks that the timestamps associated with keys
2473 and signatures have plausible values. However, sometimes a sig‐
2474 nature seems to be older than the key due to clock problems.
2475 This option makes these checks just a warning. See also
2476 --ignore-valid-from for timestamp issues on subkeys.
2477 --ignore-valid-from
2480 GnuPG normally does not select and use subkeys created in the
2481 future. This option allows the use of such keys and thus
2482 exhibits the pre-1.0.7 behaviour. You should not use this option
2483 unless you there is some clock problem. See also --ignore-time-
2484 conflict for timestamp issues with signatures.
2485 --ignore-crc-error
2488 The ASCII armor used by OpenPGP is protected by a CRC checksum
2489 against transmission errors. Occasionally the CRC gets mangled
2490 somewhere on the transmission channel but the actual content
2491 (which is protected by the OpenPGP protocol anyway) is still
2492 okay. This option allows GnuPG to ignore CRC errors.
2493 --ignore-mdc-error
2496 This option changes a MDC integrity protection failure into a
2497 warning. This can be useful if a message is partially corrupt,
2498 but it is necessary to get as much data as possible out of the
2499 corrupt message. However, be aware that a MDC protection fail‐
2500 ure may also mean that the message was tampered with intention‐
2501 ally by an attacker.
2502 --no-default-keyring
2505 Do not add the default keyrings to the list of keyrings. Note
2506 that GnuPG will not operate without any keyrings, so if you use
2507 this option and do not provide alternate keyrings via --keyring
2508 or --secret-keyring, then GnuPG will still use the default pub‐
2509 lic or secret keyrings.
2510 --skip-verify
2513 Skip the signature verification step. This may be used to make
2514 the decryption faster if the signature verification is not
2515 needed.
2516 --with-key-data
2519 Print key listings delimited by colons (like --with-colons) and
2520 print the public key data.
2521 --fast-list-mode
2524 Changes the output of the list commands to work faster; this is
2525 achieved by leaving some parts empty. Some applications don't
2526 need the user ID and the trust information given in the list‐
2527 ings. By using this options they can get a faster listing. The
2528 exact behaviour of this option may change in future versions.
2529 If you are missing some information, don't use this option.
2530 --no-literal
2533 This is not for normal use. Use the source to see for what it
2534 might be useful.
2535 --set-filesize
2538 This is not for normal use. Use the source to see for what it
2539 might be useful.
2540 --show-session-key
2543 Display the session key used for one message. See --override-
2544 session-key for the counterpart of this option.
2545 We think that Key Escrow is a Bad Thing; however the user should
2547 have the freedom to decide whether to go to prison or to reveal
2548 the content of one specific message without compromising all
2549 messages ever encrypted for one secret key. DON'T USE IT UNLESS
2550 YOU ARE REALLY FORCED TO DO SO.
2551 --override-session-key string
2554 Don't use the public key but the session key string. The format
2555 of this string is the same as the one printed by --show-session-
2556 key. This option is normally not used but comes handy in case
2557 someone forces you to reveal the content of an encrypted mes‐
2558 sage; using this option you can do this without handing out the
2559 secret key.
2560 --ask-sig-expire
2563 --no-ask-sig-expire
2565 When making a data signature, prompt for an expiration time. If
2566 this option is not specified, the expiration time set via
2567 --default-sig-expire is used. --no-ask-sig-expire disables this
2568 option. Note that by default, --force-v3-sigs is set which also
2569 disables this option. If you want signature expiration, you must
2570 set --no-force-v3-sigs as well as turning --ask-sig-expire on.
2571 --default-sig-expire
2574 The default expiration time to use for signature expiration.
2575 Valid values are "0" for no expiration, a number followed by the
2576 letter d (for days), w (for weeks), m (for months), or y (for
2577 years) (for example "2m" for two months, or "5y" for five
2578 years), or an absolute date in the form YYYY-MM-DD. Defaults to
2579 "0".
2580 --ask-cert-expire
2583 --no-ask-cert-expire
2585 When making a key signature, prompt for an expiration time. If
2586 this option is not specified, the expiration time set via
2587 --default-cert-expire is used. --no-ask-cert-expire disables
2588 this option.
2589 --default-cert-expire
2592 The default expiration time to use for key signature expiration.
2593 Valid values are "0" for no expiration, a number followed by the
2594 letter d (for days), w (for weeks), m (for months), or y (for
2595 years) (for example "2m" for two months, or "5y" for five
2596 years), or an absolute date in the form YYYY-MM-DD. Defaults to
2597 "0".
2598 --allow-secret-key-import
2601 This is an obsolete option and is not used anywhere.
2602 --allow-multiple-messages
2605 --no-allow-multiple-messages
2607 Allow processing of multiple OpenPGP messages contained in a
2608 single file or stream. Some programs that call GPG are not pre‐
2609 pared to deal with multiple messages being processed together,
2610 so this option defaults to no. Note that versions of GPG prior
2611 to 1.4.7 always allowed multiple messages.
2612 Warning: Do not use this option unless you need it as a tempo‐
2614 rary workaround!
2615 --enable-special-filenames
2619 This options enables a mode in which filenames of the form
2620 ‘-&n’, where n is a non-negative decimal number, refer to the
2621 file descriptor n and not to a file with that name.
2622 --no-expensive-trust-checks
2625 Experimental use only.
2626 --preserve-permissions
2629 Don't change the permissions of a secret keyring back to user
2630 read/write only. Use this option only if you really know what
2631 you are doing.
2632 --default-preference-list string
2635 Set the list of default preferences to string. This preference
2636 list is used for new keys and becomes the default for "setpref"
2637 in the edit menu.
2638 --default-keyserver-url name
2641 Set the default keyserver URL to name. This keyserver will be
2642 used as the keyserver URL when writing a new self-signature on a
2643 key, which includes key generation and changing preferences.
2644 --list-config
2647 Display various internal configuration parameters of GnuPG. This
2648 option is intended for external programs that call GnuPG to per‐
2649 form tasks, and is thus not generally useful. See the file
2650 ‘doc/DETAILS’ in the source distribution for the details of
2651 which configuration items may be listed. --list-config is only
2652 usable with --with-colons set.
2653 --gpgconf-list
2656 This command is similar to --list-config but in general only
2657 internally used by the gpgconf tool.
2658 --gpgconf-test
2661 This is more or less dummy action. However it parses the con‐
2662 figuration file and returns with failure if the configuration
2663 file would prevent gpg from startup. Thus it may be used to run
2664 a syntax check on the configuration file.
2665 Deprecated options
2670 --show-photos
2676 --no-show-photos
2678 Causes --list-keys, --list-sigs, --list-public-keys, --list-
2679 secret-keys, and verifying a signature to also display the photo
2680 ID attached to the key, if any. See also --photo-viewer. These
2681 options are deprecated. Use --list-options [no-]show-photos
2682 and/or --verify-options [no-]show-photos instead.
2683 --show-keyring
2686 Display the keyring name at the head of key listings to show
2687 which keyring a given key resides on. This option is deprecated:
2688 use --list-options [no-]show-keyring instead.
2689 --always-trust
2693 Identical to --trust-model always. This option is deprecated.
2694 --show-notation
2697 --no-show-notation
2699 Show signature notations in the --list-sigs or --check-sigs
2700 listings as well as when verifying a signature with a notation
2701 in it. These options are deprecated. Use --list-options
2702 [no-]show-notation and/or --verify-options [no-]show-notation
2703 instead.
2704 --show-policy-url
2707 --no-show-policy-url
2709 Show policy URLs in the --list-sigs or --check-sigs listings as
2710 well as when verifying a signature with a policy URL in it.
2711 These options are deprecated. Use --list-options [no-]show-pol‐
2712 icy-url and/or --verify-options [no-]show-policy-url instead.
2713
2720 gpg -se -r Bob file
2721 sign and encrypt for user Bob
2722 gpg --clearsign file
2725 make a clear text signature
2726 gpg -sb file
2729 make a detached signature
2730 gpg -u 0x12345678 -sb file
2733 make a detached signature with the key 0x12345678
2734 gpg --list-keys user_ID
2737 show keys
2738 gpg --fingerprint user_ID
2741 show fingerprint
2742 gpg --verify pgpfile
2745 gpg --verify sigfile
2747 Verify the signature of the file but do not output the data. The
2748 second form is used for detached signatures, where sigfile is
2749 the detached signature (either ASCII armored or binary) and are
2750 the signed data; if this is not given, the name of the file
2751 holding the signed data is constructed by cutting off the exten‐
2752 sion (".asc" or ".sig") of sigfile or by asking the user for the
2753 filename.
2754
2759 There are different ways to specify a user ID to GnuPG. Some of them
2760 are only valid for gpg others are only good for gpgsm. Here is the
2761 entire list of ways to specify a key:
2762 By key Id.
2766 This format is deduced from the length of the string and its
2767 content or 0x prefix. The key Id of an X.509 certificate are the
2768 low 64 bits of its SHA-1 fingerprint. The use of key Ids is
2769 just a shortcut, for all automated processing the fingerprint
2770 should be used.
2771 When using gpg an exclamation mark (!) may be appended to force
2773 using the specified primary or secondary key and not to try and
2774 calculate which primary or secondary key to use.
2775 The last four lines of the example give the key ID in their long
2777 form as internally used by the OpenPGP protocol. You can see the
2778 long key ID using the option --with-colons.
2779 234567C4
2781 0F34E556E
2782 01347A56A
2783 0xAB123456
2784 234AABBCC34567C4
2786 0F323456784E56EAB
2787 01AB3FED1347A5612
2788 0x234AABBCC34567C4
2789 By fingerprint.
2794 This format is deduced from the length of the string and its
2795 content or the 0x prefix. Note, that only the 20 byte version
2796 fingerprint is available with gpgsm (i.e. the SHA-1 hash of the
2797 certificate).
2798 When using gpg an exclamation mark (!) may be appended to force
2800 using the specified primary or secondary key and not to try and
2801 calculate which primary or secondary key to use.
2802 The best way to specify a key Id is by using the fingerprint.
2804 This avoids any ambiguities in case that there are duplicated
2805 key IDs.
2806 1234343434343434C434343434343434
2808 123434343434343C3434343434343734349A3434
2809 0E12343434343434343434EAB3484343434343434
2810 0xE12343434343434343434EAB3484343434343434
2811 (gpgsm also accepts colons between each pair of hexadecimal digits
2814 because this is the de-facto standard on how to present X.509 finger‐
2815 prints.)
2816 By exact match on OpenPGP user ID.
2819 This is denoted by a leading equal sign. It does not make sense
2820 for X.509 certificates.
2821 =Heinrich Heine <heinrichh@uni-duesseldorf.de>
2823 By exact match on an email address.
2826 This is indicated by enclosing the email address in the usual
2827 way with left and right angles.
2828 <heinrichh@uni-duesseldorf.de>
2830 By word match.
2834 All words must match exactly (not case sensitive) but can appear
2835 in any order in the user ID or a subjects name. Words are any
2836 sequences of letters, digits, the underscore and all characters
2837 with bit 7 set.
2838 +Heinrich Heine duesseldorf
2840 By exact match on the subject's DN.
2843 This is indicated by a leading slash, directly followed by the
2844 RFC-2253 encoded DN of the subject. Note that you can't use the
2845 string printed by "gpgsm --list-keys" because that one as been
2846 reordered and modified for better readability; use --with-colons
2847 to print the raw (but standard escaped) RFC-2253 string
2848 /CN=Heinrich Heine,O=Poets,L=Paris,C=FR
2850 By exact match on the issuer's DN.
2853 This is indicated by a leading hash mark, directly followed by a
2854 slash and then directly followed by the rfc2253 encoded DN of
2855 the issuer. This should return the Root cert of the issuer.
2856 See note above.
2857 #/CN=Root Cert,O=Poets,L=Paris,C=FR
2859 By exact match on serial number and issuer's DN.
2863 This is indicated by a hash mark, followed by the hexadecimal
2864 representation of the serial number, then followed by a slash
2865 and the RFC-2253 encoded DN of the issuer. See note above.
2866 #4F03/CN=Root Cert,O=Poets,L=Paris,C=FR
2868 By keygrip
2871 This is indicated by an ampersand followed by the 40 hex digits
2872 of a keygrip. gpgsm prints the keygrip when using the command
2873 --dump-cert. It does not yet work for OpenPGP keys.
2874 &D75F22C3F86E355877348498CDC92BD21010A480
2876 By substring match.
2880 This is the default mode but applications may want to explicitly
2881 indicate this by putting the asterisk in front. Match is not
2882 case sensitive.
2883 Heine
2885 *Heine
2886 Please note that we have reused the hash mark identifier which was used
2890 in old GnuPG versions to indicate the so called local-id. It is not
2891 anymore used and there should be no conflict when used with X.509
2892 stuff.
2893 Using the RFC-2253 format of DNs has the drawback that it is not possi‐
2895 ble to map them back to the original encoding, however we don't have to
2896 do this because our key database stores this encoding as meta data.
2897
2903 There are a few configuration files to control certain aspects of
2904 gpg2's operation. Unless noted, they are expected in the current home
2905 directory (see: [option --homedir]).
2906 gpg.conf
2910 This is the standard configuration file read by gpg2 on startup.
2911 It may contain any valid long option; the leading two dashes may
2912 not be entered and the option may not be abbreviated. This
2913 default name may be changed on the command line (see: [option
2914 --options]). You should backup this file.
2915 Note that on larger installations, it is useful to put predefined files
2918 into the directory ‘/etc/skel/.gnupg/’ so that newly created users
2919 start up with a working configuration. For existing users the a small
2920 helper script is provided to create these files (see: [addgnupghome]).
2921 For internal purposes gpg2 creates and maintains a few other files;
2923 They all live in in the current home directory (see: [option --home‐
2924 dir]). Only the gpg2 may modify these files.
2925 ~/.gnupg/secring.gpg
2929 The secret keyring. You should backup this file.
2930 ~/.gnupg/secring.gpg.lock
2933 The lock file for the secret keyring.
2934 ~/.gnupg/pubring.gpg
2937 The public keyring. You should backup this file.
2938 ~/.gnupg/pubring.gpg.lock
2941 The lock file for the public keyring.
2942 ~/.gnupg/trustdb.gpg
2945 The trust database. There is no need to backup this file; it is
2946 better to backup the ownertrust values (see: [option --export-
2947 ownertrust]).
2948 ~/.gnupg/trustdb.gpg.lock
2951 The lock file for the trust database.
2952 ~/.gnupg/random_seed
2955 A file used to preserve the state of the internal random pool.
2956 /usr[/local]/share/gnupg/options.skel
2959 The skeleton options file.
2960 /usr[/local]/lib/gnupg/
2963 Default location for extensions.
2964 Operation is further controlled by a few environment variables:
2967 HOME Used to locate the default home directory.
2971 GNUPGHOME
2974 If set directory used instead of "~/.gnupg".
2975 GPG_AGENT_INFO
2978 Used to locate the gpg-agent. The value consists of 3 colon
2979 delimited fields: The first is the path to the Unix Domain
2980 Socket, the second the PID of the gpg-agent and the protocol
2981 version which should be set to 1. When starting the gpg-agent as
2982 described in its documentation, this variable is set to the cor‐
2983 rect value. The option --gpg-agent-info can be used to override
2984 it.
2985 PINENTRY_USER_DATA
2988 This value is passed via gpg-agent to pinentry. It is useful to
2989 convey extra information to a custom pinentry.
2990 COLUMNS
2993 LINES Used to size some displays to the full size of the screen.
2995 LANGUAGE
2999 Apart from its use by GNU, it is used in the W32 version to
3000 override the language selection done through the Registry. If
3001 used and set to a valid and available language name (langid),
3002 the file with the translation is loaded from
3003 gpgdir/gnupg.nls/langid.mo. Here gpgdir is the directory out of
3004 which the gpg binary has been loaded. If it can't be loaded the
3005 Registry is tried and as last resort the native Windows locale
3006 system is used.
3007
3013 On many systems this program should be installed as setuid(root). This
3014 is necessary to lock memory pages. Locking memory pages prevents the
3015 operating system from writing memory pages (which may contain
3016 passphrases or other sensitive material) to disk. If you get no warning
3017 message about insecure memory your operating system supports locking
3018 without being root. The program drops root privileges as soon as locked
3019 memory is allocated.
3020 Note also that some systems (especially laptops) have the ability to
3022 ``suspend to disk'' (also known as ``safe sleep'' or ``hibernate'').
3023 This writes all memory to disk before going into a low power or even
3024 powered off mode. Unless measures are taken in the operating system to
3025 protect the saved memory, passphrases or other sensitive material may
3026 be recoverable from it later.
3027
3030 gpgv(1), gpgsm(1), gpg-agent(1)
3031 The full documentation for this tool is maintained as a Texinfo manual.
3033 If GnuPG and the info program are properly installed at your site, the
3034 command
3035 info gnupg
3037 should give you access to the complete manual including a menu struc‐
3039 ture and an index.
3040GnuPG 2.0.14 2018-07-13 GPG2(1)