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 commonly installed under 21 the name gpg2 and more targeted to the desktop as it requires several 22 other modules to be installed. The standalone version will be kept 23 maintained and it is possible to install both versions on the same sys‐ 24 tem. If you need to use different configuration files, you should make 25 use of something 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 Note: When verifying a cleartext signature, gpg verifies only 206 what makes up the cleartext signed data and not any extra data 207 outside of the cleartext signature or header lines following 208 directly the dash marker line. The option --output may be used 209 to write out the actual signed data; but there are other pit‐ 210 falls with this format as well. It is suggested to avoid clear‐ 211 text signatures in favor of detached signatures. 212 --multifile 215 This modifies certain other commands to accept multiple files 216 for processing on the command line or read from STDIN with each 217 filename on a separate line. This allows for many files to be 218 processed at once. --multifile may currently be used along with 219 --verify, --encrypt, and --decrypt. Note that --multifile --ver‐ 220 ify may not be used with detached signatures. 221 --verify-files 224 Identical to --multifile --verify. 225 --encrypt-files 228 Identical to --multifile --encrypt. 229 --decrypt-files 232 Identical to --multifile --decrypt. 233 --list-keys 236 -k 238 --list-public-keys 240 List all keys from the public keyrings, or just the keys given 241 on the command line. 242 Avoid using the output of this command in scripts or other pro‐ 244 grams as it is likely to change as GnuPG changes. See --with- 245 colons for a machine-parseable key listing command that is 246 appropriate for use in scripts and other programs. 247 --list-secret-keys 250 -K List all keys from the secret keyrings, or just the ones given 252 on the command line. A # after the letters sec means that the 253 secret key is not usable (for example, if it was created via 254 --export-secret-subkeys). 255 --list-sigs 258 Same as --list-keys, but the signatures are listed too. This 259 command has the same effect as using --list-keys with --with- 260 sig-list. 261 For each signature listed, there are several flags in between 263 the "sig" tag and keyid. These flags give additional information 264 about each signature. From left to right, they are the numbers 265 1-3 for certificate check level (see --ask-cert-level), "L" for 266 a local or non-exportable signature (see --lsign-key), "R" for a 267 nonRevocable signature (see the --edit-key command "nrsign"), 268 "P" for a signature that contains a policy URL (see --cert-pol‐ 269 icy-url), "N" for a signature that contains a notation (see 270 --cert-notation), "X" for an eXpired signature (see --ask-cert- 271 expire), and the numbers 1-9 or "T" for 10 and above to indicate 272 trust signature levels (see the --edit-key command "tsign"). 273 --check-sigs 276 Same as --list-sigs, but the signatures are verified. Note that 277 for performance reasons the revocation status of a signing key 278 is not shown. This command has the same effect as using --list- 279 keys with --with-sig-check. 280 The status of the verification is indicated by a flag directly 282 following the "sig" tag (and thus before the flags described 283 above for --list-sigs). A "!" indicates that the signature has 284 been successfully verified, a "-" denotes a bad signature and a 285 "%" is used if an error occurred while checking the signature 286 (e.g. a non supported algorithm). 287 --locate-keys 290 Locate the keys given as arguments. This command basically uses 291 the same algorithm as used when locating keys for encryption or 292 signing and may thus be used to see what keys gpg2 might use. 293 In particular external methods as defined by --auto-key-locate 294 may be used to locate a key. Only public keys are listed. 295 --fingerprint 299 List all keys (or the specified ones) along with their finger‐ 300 prints. This is the same output as --list-keys but with the 301 additional output of a line with the fingerprint. May also be 302 combined with --list-sigs or --check-sigs. If this command is 303 given twice, the fingerprints of all secondary keys are listed 304 too. 305 --list-packets 308 List only the sequence of packets. This is mainly useful for 309 debugging. 310 --card-edit 314 Present a menu to work with a smartcard. The subcommand "help" 315 provides an overview on available commands. For a detailed 316 description, please see the Card HOWTO at 317 http://www.gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO . 318 --card-status 321 Show the content of the smart card. 322 --change-pin 325 Present a menu to allow changing the PIN of a smartcard. This 326 functionality is also available as the subcommand "passwd" with 327 the --card-edit command. 328 --delete-key name 331 Remove key from the public keyring. In batch mode either --yes 332 is required or the key must be specified by fingerprint. This is 333 a safeguard against accidental deletion of multiple keys. 334 --delete-secret-key name 337 Remove key from the secret keyring. In batch mode the key must 338 be specified by fingerprint. 339 --delete-secret-and-public-key name 342 Same as --delete-key, but if a secret key exists, it will be 343 removed first. In batch mode the key must be specified by fin‐ 344 gerprint. 345 --export 348 Either export all keys from all keyrings (default keyrings and 349 those registered via option --keyring), or if at least one name 350 is given, those of the given name. The new keyring is written to 351 STDOUT or to the file given with option --output. Use together 352 with --armor to mail those keys. 353 --send-keys key IDs 356 Similar to --export but sends the keys to a keyserver. Finger‐ 357 prints may be used instead of key IDs. Option --keyserver must 358 be used to give the name of this keyserver. Don't send your com‐ 359 plete keyring to a keyserver --- select only those keys which 360 are new or changed by you. If no key IDs are given, gpg does 361 nothing. 362 --export-secret-keys 365 --export-secret-subkeys 367 Same as --export, but exports the secret keys instead. This is 368 normally not very useful and a security risk. The second form 369 of the command has the special property to render the secret 370 part of the primary key useless; this is a GNU extension to 371 OpenPGP and other implementations can not be expected to suc‐ 372 cessfully import such a key. See the option --simple-sk-check‐ 373 sum if you want to import such an exported key with an older 374 OpenPGP implementation. 375 --import 378 --fast-import 380 Import/merge keys. This adds the given keys to the keyring. The 381 fast version is currently just a synonym. 382 There are a few other options which control how this command 384 works. Most notable here is the --import-options merge-only 385 option which does not insert new keys but does only the merging 386 of new signatures, user-IDs and subkeys. 387 --recv-keys key IDs 390 Import the keys with the given key IDs from a keyserver. Option 391 --keyserver must be used to give the name of this keyserver. 392 --refresh-keys 395 Request updates from a keyserver for keys that already exist on 396 the local keyring. This is useful for updating a key with the 397 latest signatures, user IDs, etc. Calling this with no arguments 398 will refresh the entire keyring. Option --keyserver must be used 399 to give the name of the keyserver for all keys that do not have 400 preferred keyservers set (see --keyserver-options honor-key‐ 401 server-url). 402 --search-keys names 405 Search the keyserver for the given names. Multiple names given 406 here will be joined together to create the search string for the 407 keyserver. Option --keyserver must be used to give the name of 408 this keyserver. Keyservers that support different search meth‐ 409 ods allow using the syntax specified in "How to specify a user 410 ID" below. Note that different keyserver types support different 411 search methods. Currently only LDAP supports them all. 412 --fetch-keys URIs 415 Retrieve keys located at the specified URIs. Note that different 416 installations of GnuPG may support different protocols (HTTP, 417 FTP, LDAP, etc.) 418 --update-trustdb 421 Do trust database maintenance. This command iterates over all 422 keys and builds the Web of Trust. This is an interactive command 423 because it may have to ask for the "ownertrust" values for keys. 424 The user has to give an estimation of how far she trusts the 425 owner of the displayed key to correctly certify (sign) other 426 keys. GnuPG only asks for the ownertrust value if it has not yet 427 been assigned to a key. Using the --edit-key menu, the assigned 428 value can be changed at any time. 429 --check-trustdb 432 Do trust database maintenance without user interaction. From 433 time to time the trust database must be updated so that expired 434 keys or signatures and the resulting changes in the Web of Trust 435 can be tracked. Normally, GnuPG will calculate when this is 436 required and do it automatically unless --no-auto-check-trustdb 437 is set. This command can be used to force a trust database check 438 at any time. The processing is identical to that of --update- 439 trustdb but it skips keys with a not yet defined "ownertrust". 440 For use with cron jobs, this command can be used together with 442 --batch in which case the trust database check is done only if a 443 check is needed. To force a run even in batch mode add the 444 option --yes. 445 --export-ownertrust 449 Send the ownertrust values to STDOUT. This is useful for backup 450 purposes as these values are the only ones which can't be re- 451 created from a corrupted trustdb. Example: 452 gpg2 --export-ownertrust > otrust.txt 453 --import-ownertrust 457 Update the trustdb with the ownertrust values stored in files 458 (or STDIN if not given); existing values will be overwritten. 459 In case of a severely damaged trustdb and if you have a recent 460 backup of the ownertrust values (e.g. in the file ‘otrust.txt’, 461 you may re-create the trustdb using these commands: 462 cd ~/.gnupg 463 rm trustdb.gpg 464 gpg2 --import-ownertrust < otrust.txt 465 --rebuild-keydb-caches 469 When updating from version 1.0.6 to 1.0.7 this command should be 470 used to create signature caches in the keyring. It might be 471 handy in other situations too. 472 --print-md algo 475 --print-mds 477 Print message digest of algorithm ALGO for all given files or 478 STDIN. With the second form (or a deprecated "*" as algo) 479 digests for all available algorithms are printed. 480 --gen-random 0|1|2 count 483 Emit count random bytes of the given quality level 0, 1 or 2. If 484 count is not given or zero, an endless sequence of random bytes 485 will be emitted. If used with --armor the output will be base64 486 encoded. PLEASE, don't use this command unless you know what 487 you are doing; it may remove precious entropy from the system! 488 --gen-prime mode bits 491 Use the source, Luke :-). The output format is still subject to 492 change. 493 --enarmor 497 --dearmor 499 Pack or unpack an arbitrary input into/from an OpenPGP ASCII 500 armor. This is a GnuPG extension to OpenPGP and in general not 501 very useful. 502 How to manage your keys 508 This section explains the main commands for key management 511 --gen-key 515 Generate a new key pair. This command is normally only used 516 interactively. 517 There is an experimental feature which allows you to create keys 519 in batch mode. See the file ‘doc/DETAILS’ in the source distri‐ 520 bution on how to use this. 521 --gen-revoke name 524 Generate a revocation certificate for the complete key. To 525 revoke a subkey or a signature, use the --edit command. 526 --desig-revoke name 529 Generate a designated revocation certificate for a key. This 530 allows a user (with the permission of the keyholder) to revoke 531 someone else's key. 532 --edit-key 536 Present a menu which enables you to do most of the key manage‐ 537 ment related tasks. It expects the specification of a key on 538 the command line. 539 uid n Toggle selection of user ID or photographic user ID with 543 index n. Use * to select all and 0 to deselect all. 544 key n Toggle selection of subkey with index n. Use * to select 547 all and 0 to deselect all. 548 sign Make a signature on key of user name If the key is not 551 yet signed by the default user (or the users given with 552 -u), the program displays the information of the key 553 again, together with its fingerprint and asks whether it 554 should be signed. This question is repeated for all users 555 specified with -u. 556 lsign Same as "sign" but the signature is marked as non- 559 exportable and will therefore never be used by others. 560 This may be used to make keys valid only in the local 561 environment. 562 nrsign Same as "sign" but the signature is marked as non-revoca‐ 565 ble and can therefore never be revoked. 566 tsign Make a trust signature. This is a signature that combines 569 the notions of certification (like a regular signature), 570 and trust (like the "trust" command). It is generally 571 only useful in distinct communities or groups. 572 Note that "l" (for local / non-exportable), "nr" (for non-revo‐ 574 cable, and "t" (for trust) may be freely mixed and prefixed to 575 "sign" to create a signature of any type desired. 576 delsig Delete a signature. Note that it is not possible to 580 retract a signature, once it has been send to the public 581 (i.e. to a keyserver). In that case you better use 582 revsig. 583 revsig Revoke a signature. For every signature which has been 586 generated by one of the secret keys, GnuPG asks whether a 587 revocation certificate should be generated. 588 check Check the signatures on all selected user IDs. 591 adduid Create an additional user ID. 594 addphoto 597 Create a photographic user ID. This will prompt for a 598 JPEG file that will be embedded into the user ID. Note 599 that a very large JPEG will make for a very large key. 600 Also note that some programs will display your JPEG 601 unchanged (GnuPG), and some programs will scale it to fit 602 in a dialog box (PGP). 603 showphoto 606 Display the selected photographic user ID. 607 deluid Delete a user ID or photographic user ID. Note that it 610 is not possible to retract a user id, once it has been 611 send to the public (i.e. to a keyserver). In that case 612 you better use revuid. 613 revuid Revoke a user ID or photographic user ID. 616 primary 619 Flag the current user id as the primary one, removes the 620 primary user id flag from all other user ids and sets the 621 timestamp of all affected self-signatures one second 622 ahead. Note that setting a photo user ID as primary makes 623 it primary over other photo user IDs, and setting a regu‐ 624 lar user ID as primary makes it primary over other regu‐ 625 lar user IDs. 626 keyserver 629 Set a preferred keyserver for the specified user ID(s). 630 This allows other users to know where you prefer they get 631 your key from. See --keyserver-options honor-keyserver- 632 url for more on how this works. Setting a value of 633 "none" removes an existing preferred keyserver. 634 notation 637 Set a name=value notation for the specified user ID(s). 638 See --cert-notation for more on how this works. Setting a 639 value of "none" removes all notations, setting a notation 640 prefixed with a minus sign (-) removes that notation, and 641 setting a notation name (without the =value) prefixed 642 with a minus sign removes all notations with that name. 643 pref List preferences from the selected user ID. This shows 646 the actual preferences, without including any implied 647 preferences. 648 showpref 651 More verbose preferences listing for the selected user 652 ID. This shows the preferences in effect by including the 653 implied preferences of 3DES (cipher), SHA-1 (digest), and 654 Uncompressed (compression) if they are not already 655 included in the preference list. In addition, the pre‐ 656 ferred keyserver and signature notations (if any) are 657 shown. 658 setpref string 661 Set the list of user ID preferences to string for all (or 662 just the selected) user IDs. Calling setpref with no 663 arguments sets the preference list to the default (either 664 built-in or set via --default-preference-list), and call‐ 665 ing setpref with "none" as the argument sets an empty 666 preference list. Use gpg2 --version to get a list of 667 available algorithms. Note that while you can change the 668 preferences on an attribute user ID (aka "photo ID"), 669 GnuPG does not select keys via attribute user IDs so 670 these preferences will not be used by GnuPG. 671 When setting preferences, you should list the algorithms 673 in the order which you'd like to see them used by someone 674 else when encrypting a message to your key. If you don't 675 include 3DES, it will be automatically added at the end. 676 Note that there are many factors that go into choosing an 677 algorithm (for example, your key may not be the only 678 recipient), and so the remote OpenPGP application being 679 used to send to you may or may not follow your exact cho‐ 680 sen order for a given message. It will, however, only 681 choose an algorithm that is present on the preference 682 list of every recipient key. See also the INTEROPERABIL‐ 683 ITY WITH OTHER OPENPGP PROGRAMS section below. 684 addkey Add a subkey to this key. 687 addcardkey 690 Generate a subkey on a card and add it to this key. 691 keytocard 694 Transfer the selected secret subkey (or the primary key 695 if no subkey has been selected) to a smartcard. The 696 secret key in the keyring will be replaced by a stub if 697 the key could be stored successfully on the card and you 698 use the save command later. Only certain key types may be 699 transferred to the card. A sub menu allows you to select 700 on what card to store the key. Note that it is not possi‐ 701 ble to get that key back from the card - if the card gets 702 broken your secret key will be lost unless you have a 703 backup somewhere. 704 bkuptocard file 707 Restore the given file to a card. This command may be 708 used to restore a backup key (as generated during card 709 initialization) to a new card. In almost all cases this 710 will be the encryption key. You should use this command 711 only with the corresponding public key and make sure that 712 the file given as argument is indeed the backup to 713 restore. You should then select 2 to restore as encryp‐ 714 tion key. You will first be asked to enter the 715 passphrase of the backup key and then for the Admin PIN 716 of the card. 717 delkey Remove a subkey (secondart key). Note that it is not pos‐ 720 sible to retract a subkey, once it has been send to the 721 public (i.e. to a keyserver). In that case you better 722 use revkey. 723 revkey Revoke a subkey. 726 expire Change the key or subkey expiration time. If a subkey is 729 selected, the expiration time of this subkey will be 730 changed. With no selection, the key expiration of the 731 primary key is changed. 732 trust Change the owner trust value for the key. This updates 735 the trust-db immediately and no save is required. 736 disable 739 enable Disable or enable an entire key. A disabled key can not 741 normally be used for encryption. 742 addrevoker 745 Add a designated revoker to the key. This takes one 746 optional argument: "sensitive". If a designated revoker 747 is marked as sensitive, it will not be exported by 748 default (see export-options). 749 passwd Change the passphrase of the secret key. 752 toggle Toggle between public and secret key listing. 755 clean Compact (by removing all signatures except the selfsig) 758 any user ID that is no longer usable (e.g. revoked, or 759 expired). Then, remove any signatures that are not usable 760 by the trust calculations. Specifically, this removes 761 any signature that does not validate, any signature that 762 is superseded by a later signature, revoked signatures, 763 and signatures issued by keys that are not present on the 764 keyring. 765 minimize 768 Make the key as small as possible. This removes all sig‐ 769 natures from each user ID except for the most recent 770 self-signature. 771 cross-certify 774 Add cross-certification signatures to signing subkeys 775 that may not currently have them. Cross-certification 776 signatures protect against a subtle attack against sign‐ 777 ing subkeys. See --require-cross-certification. All new 778 keys generated have this signature by default, so this 779 option is only useful to bring older keys up to date. 780 save Save all changes to the key rings and quit. 783 quit Quit the program without updating the key rings. 786 The listing shows you the key with its secondary keys and all 788 user ids. The primary user id is indicated by a dot, and 789 selected keys or user ids are indicated by an asterisk. The 790 trust value is displayed with the primary key: the first is the 791 assigned owner trust and the second is the calculated trust 792 value. Letters are used for the values: 793 - No ownertrust assigned / not yet calculated. 797 e Trust calculation has failed; probably due to an expired 800 key. 801 q Not enough information for calculation. 804 n Never trust this key. 807 m Marginally trusted. 810 f Fully trusted. 813 u Ultimately trusted. 816 --sign-key name 820 Signs a public key with your secret key. This is a shortcut ver‐ 821 sion of the subcommand "sign" from --edit. 822 --lsign-key name 825 Signs a public key with your secret key but marks it as non- 826 exportable. This is a shortcut version of the subcommand "lsign" 827 from --edit-key. 828 --passwd user_id 831 Change the passphrase of the secret key belonging to the cer‐ 832 tificate specified as user_id. This is a shortcut for the sub- 833 command passwd of the edit key menu. 834
840 gpg2 features a bunch of options to control the exact behaviour and to 841 change the default configuration. 842 Long options can be put in an options file (default 845 "~/.gnupg/gpg.conf"). Short option names will not work - for example, 846 "armor" is a valid option for the options file, while "a" is not. Do 847 not write the 2 dashes, but simply the name of the option and any 848 required arguments. Lines with a hash ('#') as the first non-white- 849 space character are ignored. Commands may be put in this file too, but 850 that is not generally useful as the command will execute automatically 851 with every execution of gpg. 852 Please remember that option parsing stops as soon as a non-option is 854 encountered, you can explicitly stop parsing by using the special 855 option --. 856 How to change the configuration 860 These options are used to change the configuration and are usually 863 found in the option file. 864 --default-key name 868 Use name as the default key to sign with. If this option is not 869 used, the default key is the first key found in the secret 870 keyring. Note that -u or --local-user overrides this option. 871 --default-recipient name 874 Use name as default recipient if option --recipient is not used 875 and don't ask if this is a valid one. name must be non-empty. 876 --default-recipient-self 879 Use the default key as default recipient if option --recipient 880 is not used and don't ask if this is a valid one. The default 881 key is the first one from the secret keyring or the one set with 882 --default-key. 883 --no-default-recipient 886 Reset --default-recipient and --default-recipient-self. 887 -v, --verbose 890 Give more information during processing. If used twice, the 891 input data is listed in detail. 892 --no-verbose 895 Reset verbose level to 0. 896 -q, --quiet 899 Try to be as quiet as possible. 900 --batch 903 --no-batch 905 Use batch mode. Never ask, do not allow interactive commands. 906 --no-batch disables this option. Note that even with a filename 907 given on the command line, gpg might still need to read from 908 STDIN (in particular if gpg figures that the input is a detached 909 signature and no data file has been specified). Thus if you do 910 not want to feed data via STDIN, you should connect STDIN to 911 ‘/dev/null’. 912 --no-tty 915 Make sure that the TTY (terminal) is never used for any output. 916 This option is needed in some cases because GnuPG sometimes 917 prints warnings to the TTY even if --batch is used. 918 --yes Assume "yes" on most questions. 921 --no Assume "no" on most questions. 924 --list-options parameters 928 This is a space or comma delimited string that gives options 929 used when listing keys and signatures (that is, --list-keys, 930 --list-sigs, --list-public-keys, --list-secret-keys, and the 931 --edit-key functions). Options can be prepended with a no- 932 (after the two dashes) to give the opposite meaning. The 933 options are: 934 show-photos 938 Causes --list-keys, --list-sigs, --list-public-keys, and 939 --list-secret-keys to display any photo IDs attached to 940 the key. Defaults to no. See also --photo-viewer. Does 941 not work with --with-colons: see --attribute-fd for the 942 appropriate way to get photo data for scripts and other 943 frontends. 944 show-policy-urls 947 Show policy URLs in the --list-sigs or --check-sigs list‐ 948 ings. Defaults to no. 949 show-notations 952 show-std-notations 954 show-user-notations 956 Show all, IETF standard, or user-defined signature nota‐ 957 tions in the --list-sigs or --check-sigs listings. 958 Defaults to no. 959 show-keyserver-urls 962 Show any preferred keyserver URL in the --list-sigs or 963 --check-sigs listings. Defaults to no. 964 show-uid-validity 967 Display the calculated validity of user IDs during key 968 listings. Defaults to no. 969 show-unusable-uids 972 Show revoked and expired user IDs in key listings. 973 Defaults to no. 974 show-unusable-subkeys 977 Show revoked and expired subkeys in key listings. 978 Defaults to no. 979 show-keyring 982 Display the keyring name at the head of key listings to 983 show which keyring a given key resides on. Defaults to 984 no. 985 show-sig-expire 988 Show signature expiration dates (if any) during --list- 989 sigs or --check-sigs listings. Defaults to no. 990 show-sig-subpackets 993 Include signature subpackets in the key listing. This 994 option can take an optional argument list of the subpack‐ 995 ets to list. If no argument is passed, list all subpack‐ 996 ets. Defaults to no. This option is only meaningful when 997 using --with-colons along with --list-sigs or --check- 998 sigs. 999 --verify-options parameters 1003 This is a space or comma delimited string that gives options 1004 used when verifying signatures. Options can be prepended with a 1005 `no-' to give the opposite meaning. The options are: 1006 show-photos 1010 Display any photo IDs present on the key that issued the 1011 signature. Defaults to no. See also --photo-viewer. 1012 show-policy-urls 1015 Show policy URLs in the signature being verified. 1016 Defaults to no. 1017 show-notations 1020 show-std-notations 1022 show-user-notations 1024 Show all, IETF standard, or user-defined signature nota‐ 1025 tions in the signature being verified. Defaults to IETF 1026 standard. 1027 show-keyserver-urls 1030 Show any preferred keyserver URL in the signature being 1031 verified. Defaults to no. 1032 show-uid-validity 1035 Display the calculated validity of the user IDs on the 1036 key that issued the signature. Defaults to no. 1037 show-unusable-uids 1040 Show revoked and expired user IDs during signature veri‐ 1041 fication. Defaults to no. 1042 show-primary-uid-only 1045 Show only the primary user ID during signature verifica‐ 1046 tion. That is all the AKA lines as well as photo Ids are 1047 not shown with the signature verification status. 1048 pka-lookups 1051 Enable PKA lookups to verify sender addresses. Note that 1052 PKA is based on DNS, and so enabling this option may dis‐ 1053 close information on when and what signatures are veri‐ 1054 fied or to whom data is encrypted. This is similar to the 1055 "web bug" described for the auto-key-retrieve feature. 1056 pka-trust-increase 1059 Raise the trust in a signature to full if the signature 1060 passes PKA validation. This option is only meaningful if 1061 pka-lookups is set. 1062 --enable-dsa2 1065 --disable-dsa2 1067 Enable hash truncation for all DSA keys even for old DSA Keys up 1068 to 1024 bit. This is also the default with --openpgp. Note 1069 that older versions of GnuPG also required this flag to allow 1070 the generation of DSA larger than 1024 bit. 1071 --photo-viewer string 1074 This is the command line that should be run to view a photo ID. 1075 "%i" will be expanded to a filename containing the photo. "%I" 1076 does the same, except the file will not be deleted once the 1077 viewer exits. Other flags are "%k" for the key ID, "%K" for the 1078 long key ID, "%f" for the key fingerprint, "%t" for the exten‐ 1079 sion of the image type (e.g. "jpg"), "%T" for the MIME type of 1080 the image (e.g. "image/jpeg"), "%v" for the single-character 1081 calculated validity of the image being viewed (e.g. "f"), "%V" 1082 for the calculated validity as a string (e.g. "full"), and "%%" 1083 for an actual percent sign. If neither %i or %I are present, 1084 then the photo will be supplied to the viewer on standard input. 1085 The default viewer is "xloadimage -fork -quiet -title 'KeyID 1087 0x%k' STDIN". Note that if your image viewer program is not 1088 secure, then executing it from GnuPG does not make it secure. 1089 --exec-path string 1092 Sets a list of directories to search for photo viewers and key‐ 1093 server helpers. If not provided, keyserver helpers use the com‐ 1094 piled-in default directory, and photo viewers use the $PATH 1095 environment variable. Note, that on W32 system this value is 1096 ignored when searching for keyserver helpers. 1097 --keyring file 1100 Add file to the current list of keyrings. If file begins with a 1101 tilde and a slash, these are replaced by the $HOME directory. If 1102 the filename does not contain a slash, it is assumed to be in 1103 the GnuPG home directory ("~/.gnupg" if --homedir or $GNUPGHOME 1104 is not used). 1105 Note that this adds a keyring to the current list. If the intent 1107 is to use the specified keyring alone, use --keyring along with 1108 --no-default-keyring. 1109 --secret-keyring file 1112 Same as --keyring but for the secret keyrings. 1113 --primary-keyring file 1116 Designate file as the primary public keyring. This means that 1117 newly imported keys (via --import or keyserver --recv-from) will 1118 go to this keyring. 1119 --trustdb-name file 1122 Use file instead of the default trustdb. If file begins with a 1123 tilde and a slash, these are replaced by the $HOME directory. If 1124 the filename does not contain a slash, it is assumed to be in 1125 the GnuPG home directory (‘~/.gnupg’ if --homedir or $GNUPGHOME 1126 is not used). 1127 --homedir dir 1130 Set the name of the home directory to dir. If this option is not 1131 used, the home directory defaults to ‘~/.gnupg’. It is only 1132 recognized when given on the command line. It also overrides 1133 any home directory stated through the environment variable 1134 ‘GNUPGHOME’ or (on W32 systems) by means of the Registry entry 1135 HKCU\Software\GNU\GnuPG:HomeDir. 1136 --display-charset name 1144 Set the name of the native character set. This is used to con‐ 1145 vert some informational strings like user IDs to the proper 1146 UTF-8 encoding. Note that this has nothing to do with the char‐ 1147 acter set of data to be encrypted or signed; GnuPG does not 1148 recode user-supplied data. If this option is not used, the 1149 default character set is determined from the current locale. A 1150 verbosity level of 3 shows the chosen set. Valid values for 1151 name are: 1152 iso-8859-1 1156 This is the Latin 1 set. 1157 iso-8859-2 1160 The Latin 2 set. 1161 iso-8859-15 1164 This is currently an alias for the Latin 1 set. 1165 koi8-r The usual Russian set (rfc1489). 1168 utf-8 Bypass all translations and assume that the OS uses 1171 native UTF-8 encoding. 1172 --utf8-strings 1175 --no-utf8-strings 1177 Assume that command line arguments are given as UTF8 strings. 1178 The default (--no-utf8-strings) is to assume that arguments are 1179 encoded in the character set as specified by --display-charset. 1180 These options affect all following arguments. Both options may 1181 be used multiple times. 1182 --options file 1186 Read options from file and do not try to read them from the 1187 default options file in the homedir (see --homedir). This option 1188 is ignored if used in an options file. 1189 --no-options 1192 Shortcut for --options /dev/null. This option is detected before 1193 an attempt to open an option file. Using this option will also 1194 prevent the creation of a ‘~/.gnupg’ homedir. 1195 -z n 1198 --compress-level n 1200 --bzip2-compress-level n 1202 Set compression level to n for the ZIP and ZLIB compression 1203 algorithms. The default is to use the default compression level 1204 of zlib (normally 6). --bzip2-compress-level sets the compres‐ 1205 sion level for the BZIP2 compression algorithm (defaulting to 6 1206 as well). This is a different option from --compress-level since 1207 BZIP2 uses a significant amount of memory for each additional 1208 compression level. -z sets both. A value of 0 for n disables 1209 compression. 1210 --bzip2-decompress-lowmem 1213 Use a different decompression method for BZIP2 compressed files. 1214 This alternate method uses a bit more than half the memory, but 1215 also runs at half the speed. This is useful under extreme low 1216 memory circumstances when the file was originally compressed at 1217 a high --bzip2-compress-level. 1218 --mangle-dos-filenames 1222 --no-mangle-dos-filenames 1224 Older version of Windows cannot handle filenames with more than 1225 one dot. --mangle-dos-filenames causes GnuPG to replace (rather 1226 than add to) the extension of an output filename to avoid this 1227 problem. This option is off by default and has no effect on non- 1228 Windows platforms. 1229 --ask-cert-level 1232 --no-ask-cert-level 1234 When making a key signature, prompt for a certification level. 1235 If this option is not specified, the certification level used is 1236 set via --default-cert-level. See --default-cert-level for 1237 information on the specific levels and how they are used. --no- 1238 ask-cert-level disables this option. This option defaults to no. 1239 --default-cert-level n 1242 The default to use for the check level when signing a key. 1243 0 means you make no particular claim as to how carefully you 1245 verified the key. 1246 1 means you believe the key is owned by the person who claims to 1248 own it but you could not, or did not verify the key at all. This 1249 is useful for a "persona" verification, where you sign the key 1250 of a pseudonymous user. 1251 2 means you did casual verification of the key. For example, 1253 this could mean that you verified the key fingerprint and 1254 checked the user ID on the key against a photo ID. 1255 3 means you did extensive verification of the key. For example, 1257 this could mean that you verified the key fingerprint with the 1258 owner of the key in person, and that you checked, by means of a 1259 hard to forge document with a photo ID (such as a passport) that 1260 the name of the key owner matches the name in the user ID on the 1261 key, and finally that you verified (by exchange of email) that 1262 the email address on the key belongs to the key owner. 1263 Note that the examples given above for levels 2 and 3 are just 1265 that: examples. In the end, it is up to you to decide just what 1266 "casual" and "extensive" mean to you. 1267 This option defaults to 0 (no particular claim). 1269 --min-cert-level 1272 When building the trust database, treat any signatures with a 1273 certification level below this as invalid. Defaults to 2, which 1274 disregards level 1 signatures. Note that level 0 "no particular 1275 claim" signatures are always accepted. 1276 --trusted-key long key ID 1279 Assume that the specified key (which must be given as a full 8 1280 byte key ID) is as trustworthy as one of your own secret keys. 1281 This option is useful if you don't want to keep your secret keys 1282 (or one of them) online but still want to be able to check the 1283 validity of a given recipient's or signator's key. 1284 --trust-model pgp|classic|direct|always|auto 1287 Set what trust model GnuPG should follow. The models are: 1288 pgp This is the Web of Trust combined with trust signatures 1292 as used in PGP 5.x and later. This is the default trust 1293 model when creating a new trust database. 1294 classic 1297 This is the standard Web of Trust as used in PGP 2.x and 1298 earlier. 1299 direct Key validity is set directly by the user and not calcu‐ 1302 lated via the Web of Trust. 1303 always Skip key validation and assume that used keys are always 1306 fully trusted. You generally won't use this unless you 1307 are using some external validation scheme. This option 1308 also suppresses the "[uncertain]" tag printed with signa‐ 1309 ture checks when there is no evidence that the user ID is 1310 bound to the key. 1311 auto Select the trust model depending on whatever the internal 1314 trust database says. This is the default model if such a 1315 database already exists. 1316 --auto-key-locate parameters 1319 --no-auto-key-locate 1321 GnuPG can automatically locate and retrieve keys as needed using 1322 this option. This happens when encrypting to an email address 1323 (in the "user@example.com" form), and there are no user@exam‐ 1324 ple.com keys on the local keyring. This option takes any number 1325 of the following mechanisms, in the order they are to be tried: 1326 cert Locate a key using DNS CERT, as specified in rfc4398. 1330 pka Locate a key using DNS PKA. 1333 ldap Using DNS Service Discovery, check the domain in question 1336 for any LDAP keyservers to use. If this fails, attempt 1337 to locate the key using the PGP Universal method of 1338 checking 'ldap://keys.(thedomain)'. 1339 keyserver 1342 Locate a key using whatever keyserver is defined using 1343 the --keyserver option. 1344 keyserver-URL 1347 In addition, a keyserver URL as used in the --keyserver 1348 option may be used here to query that particular key‐ 1349 server. 1350 local Locate the key using the local keyrings. This mechanism 1353 allows to select the order a local key lookup is done. 1354 Thus using '--auto-key-locate local' is identical to 1355 --no-auto-key-locate. 1356 nodefault 1359 This flag disables the standard local key lookup, done 1360 before any of the mechanisms defined by the --auto-key- 1361 locate are tried. The position of this mechanism in the 1362 list does not matter. It is not required if local is 1363 also used. 1364 --keyid-format short|0xshort|long|0xlong 1368 Select how to display key IDs. "short" is the traditional 1369 8-character key ID. "long" is the more accurate (but less conve‐ 1370 nient) 16-character key ID. Add an "0x" to either to include an 1371 "0x" at the beginning of the key ID, as in 0x99242560. Note 1372 that this option is ignored if the option --with-colons is used. 1373 --keyserver name 1376 Use name as your keyserver. This is the server that --recv-keys, 1377 --send-keys, and --search-keys will communicate with to receive 1378 keys from, send keys to, and search for keys on. The format of 1379 the name is a URI: `scheme:[//]keyservername[:port]' The scheme 1380 is the type of keyserver: "hkp" for the HTTP (or compatible) 1381 keyservers, "ldap" for the LDAP keyservers, or "mailto" for the 1382 Graff email keyserver. Note that your particular installation of 1383 GnuPG may have other keyserver types available as well. Key‐ 1384 server schemes are case-insensitive. After the keyserver name, 1385 optional keyserver configuration options may be provided. These 1386 are the same as the global --keyserver-options from below, but 1387 apply only to this particular keyserver. 1388 Most keyservers synchronize with each other, so there is gener‐ 1390 ally no need to send keys to more than one server. The keyserver 1391 hkp://keys.gnupg.net uses round robin DNS to give a different 1392 keyserver each time you use it. 1393 --keyserver-options name=value1 1396 This is a space or comma delimited string that gives options for 1397 the keyserver. Options can be prefixed with a `no-' to give the 1398 opposite meaning. Valid import-options or export-options may be 1399 used here as well to apply to importing (--recv-key) or export‐ 1400 ing (--send-key) a key from a keyserver. While not all options 1401 are available for all keyserver types, some common options are: 1402 include-revoked 1406 When searching for a key with --search-keys, include keys 1407 that are marked on the keyserver as revoked. Note that 1408 not all keyservers differentiate between revoked and 1409 unrevoked keys, and for such keyservers this option is 1410 meaningless. Note also that most keyservers do not have 1411 cryptographic verification of key revocations, and so 1412 turning this option off may result in skipping keys that 1413 are incorrectly marked as revoked. 1414 include-disabled 1417 When searching for a key with --search-keys, include keys 1418 that are marked on the keyserver as disabled. Note that 1419 this option is not used with HKP keyservers. 1420 auto-key-retrieve 1423 This option enables the automatic retrieving of keys from 1424 a keyserver when verifying signatures made by keys that 1425 are not on the local keyring. 1426 Note that this option makes a "web bug" like behavior 1428 possible. Keyserver operators can see which keys you 1429 request, so by sending you a message signed by a brand 1430 new key (which you naturally will not have on your local 1431 keyring), the operator can tell both your IP address and 1432 the time when you verified the signature. 1433 honor-keyserver-url 1436 When using --refresh-keys, if the key in question has a 1437 preferred keyserver URL, then use that preferred key‐ 1438 server to refresh the key from. In addition, if auto-key- 1439 retrieve is set, and the signature being verified has a 1440 preferred keyserver URL, then use that preferred key‐ 1441 server to fetch the key from. Defaults to yes. 1442 honor-pka-record 1445 If auto-key-retrieve is set, and the signature being ver‐ 1446 ified has a PKA record, then use the PKA information to 1447 fetch the key. Defaults to yes. 1448 include-subkeys 1451 When receiving a key, include subkeys as potential tar‐ 1452 gets. Note that this option is not used with HKP key‐ 1453 servers, as they do not support retrieving keys by subkey 1454 id. 1455 use-temp-files 1458 On most Unix-like platforms, GnuPG communicates with the 1459 keyserver helper program via pipes, which is the most 1460 efficient method. This option forces GnuPG to use tempo‐ 1461 rary files to communicate. On some platforms (such as 1462 Win32 and RISC OS), this option is always enabled. 1463 keep-temp-files 1466 If using `use-temp-files', do not delete the temp files 1467 after using them. This option is useful to learn the key‐ 1468 server communication protocol by reading the temporary 1469 files. 1470 verbose 1473 Tell the keyserver helper program to be more verbose. 1474 This option can be repeated multiple times to increase 1475 the verbosity level. 1476 timeout 1479 Tell the keyserver helper program how long (in seconds) 1480 to try and perform a keyserver action before giving up. 1481 Note that performing multiple actions at the same time 1482 uses this timeout value per action. For example, when 1483 retrieving multiple keys via --recv-keys, the timeout 1484 applies separately to each key retrieval, and not to the 1485 --recv-keys command as a whole. Defaults to 30 seconds. 1486 http-proxy=value 1489 Set the proxy to use for HTTP and HKP keyservers. This 1490 overrides the "http_proxy" environment variable, if any. 1491 max-cert-size 1495 When retrieving a key via DNS CERT, only accept keys up 1496 to this size. Defaults to 16384 bytes. 1497 debug Turn on debug output in the keyserver helper program. 1500 Note that the details of debug output depends on which 1501 keyserver helper program is being used, and in turn, on 1502 any libraries that the keyserver helper program uses 1503 internally (libcurl, openldap, etc). 1504 check-cert 1507 Enable certificate checking if the keyserver presents one 1508 (for hkps or ldaps). Defaults to on. 1509 ca-cert-file 1512 Provide a certificate store to override the system 1513 default. Only necessary if check-cert is enabled, and 1514 the keyserver is using a certificate that is not present 1515 in a system default certificate list. 1516 Note that depending on the SSL library that the keyserver 1518 helper is built with, this may actually be a directory or 1519 a file. 1520 --completes-needed n 1523 Number of completely trusted users to introduce a new key signer 1524 (defaults to 1). 1525 --marginals-needed n 1528 Number of marginally trusted users to introduce a new key signer 1529 (defaults to 3) 1530 --max-cert-depth n 1533 Maximum depth of a certification chain (default is 5). 1534 --simple-sk-checksum 1537 Secret keys are integrity protected by using a SHA-1 checksum. 1538 This method is part of the upcoming enhanced OpenPGP specifica‐ 1539 tion but GnuPG already uses it as a countermeasure against cer‐ 1540 tain attacks. Old applications don't understand this new for‐ 1541 mat, so this option may be used to switch back to the old behav‐ 1542 iour. Using this option bears a security risk. Note that using 1543 this option only takes effect when the secret key is encrypted - 1544 the simplest way to make this happen is to change the passphrase 1545 on the key (even changing it to the same value is acceptable). 1546 --no-sig-cache 1549 Do not cache the verification status of key signatures. Caching 1550 gives a much better performance in key listings. However, if you 1551 suspect that your public keyring is not save against write modi‐ 1552 fications, you can use this option to disable the caching. It 1553 probably does not make sense to disable it because all kind of 1554 damage can be done if someone else has write access to your pub‐ 1555 lic keyring. 1556 --no-sig-create-check 1559 GnuPG normally verifies each signature right after creation to 1560 protect against bugs and hardware malfunctions which could leak 1561 out bits from the secret key. This extra verification needs some 1562 time (about 115% for DSA keys), and so this option can be used 1563 to disable it. However, due to the fact that the signature cre‐ 1564 ation needs manual interaction, this performance penalty does 1565 not matter in most settings. 1566 --auto-check-trustdb 1569 --no-auto-check-trustdb 1571 If GnuPG feels that its information about the Web of Trust has 1572 to be updated, it automatically runs the --check-trustdb command 1573 internally. This may be a time consuming process. --no-auto- 1574 check-trustdb disables this option. 1575 --use-agent 1578 --no-use-agent 1580 This is dummy option. gpg2 always requires the agent. 1581 --gpg-agent-info 1584 This is dummy option. It has no effect when used with gpg2. 1585 --lock-once 1588 Lock the databases the first time a lock is requested and do not 1589 release the lock until the process terminates. 1590 --lock-multiple 1593 Release the locks every time a lock is no longer needed. Use 1594 this to override a previous --lock-once from a config file. 1595 --lock-never 1598 Disable locking entirely. This option should be used only in 1599 very special environments, where it can be assured that only one 1600 process is accessing those files. A bootable floppy with a 1601 stand-alone encryption system will probably use this. Improper 1602 usage of this option may lead to data and key corruption. 1603 --exit-on-status-write-error 1606 This option will cause write errors on the status FD to immedi‐ 1607 ately terminate the process. That should in fact be the default 1608 but it never worked this way and thus we need an option to 1609 enable this, so that the change won't break applications which 1610 close their end of a status fd connected pipe too early. Using 1611 this option along with --enable-progress-filter may be used to 1612 cleanly cancel long running gpg operations. 1613 --limit-card-insert-tries n 1616 With n greater than 0 the number of prompts asking to insert a 1617 smartcard gets limited to N-1. Thus with a value of 1 gpg won't 1618 at all ask to insert a card if none has been inserted at 1619 startup. This option is useful in the configuration file in case 1620 an application does not know about the smartcard support and 1621 waits ad infinitum for an inserted card. 1622 --no-random-seed-file 1625 GnuPG uses a file to store its internal random pool over invoca‐ 1626 tions. This makes random generation faster; however sometimes 1627 write operations are not desired. This option can be used to 1628 achieve that with the cost of slower random generation. 1629 --no-greeting 1632 Suppress the initial copyright message. 1633 --no-secmem-warning 1636 Suppress the warning about "using insecure memory". 1637 --no-permission-warning 1640 Suppress the warning about unsafe file and home directory 1641 (--homedir) permissions. Note that the permission checks that 1642 GnuPG performs are not intended to be authoritative, but rather 1643 they simply warn about certain common permission problems. Do 1644 not assume that the lack of a warning means that your system is 1645 secure. 1646 Note that the warning for unsafe --homedir permissions cannot be 1648 suppressed in the gpg.conf file, as this would allow an attacker 1649 to place an unsafe gpg.conf file in place, and use this file to 1650 suppress warnings about itself. The --homedir permissions warn‐ 1651 ing may only be suppressed on the command line. 1652 --no-mdc-warning 1655 Suppress the warning about missing MDC integrity protection. 1656 --require-secmem 1659 --no-require-secmem 1661 Refuse to run if GnuPG cannot get secure memory. Defaults to no 1662 (i.e. run, but give a warning). 1663 --require-cross-certification 1667 --no-require-cross-certification 1669 When verifying a signature made from a subkey, ensure that the 1670 cross certification "back signature" on the subkey is present 1671 and valid. This protects against a subtle attack against sub‐ 1672 keys that can sign. Defaults to --require-cross-certification 1673 for gpg2. 1674 --expert 1677 --no-expert 1679 Allow the user to do certain nonsensical or "silly" things like 1680 signing an expired or revoked key, or certain potentially incom‐ 1681 patible things like generating unusual key types. This also dis‐ 1682 ables certain warning messages about potentially incompatible 1683 actions. As the name implies, this option is for experts only. 1684 If you don't fully understand the implications of what it allows 1685 you to do, leave this off. --no-expert disables this option. 1686 Key related options 1692 --recipient name 1697 -r Encrypt for user id name. If this option or --hidden-recipient 1699 is not specified, GnuPG asks for the user-id unless --default- 1700 recipient is given. 1701 --hidden-recipient name 1704 -R Encrypt for user ID name, but hide the key ID of this user's 1706 key. This option helps to hide the receiver of the message and 1707 is a limited countermeasure against traffic analysis. If this 1708 option or --recipient is not specified, GnuPG asks for the user 1709 ID unless --default-recipient is given. 1710 --encrypt-to name 1713 Same as --recipient but this one is intended for use in the 1714 options file and may be used with your own user-id as an 1715 "encrypt-to-self". These keys are only used when there are other 1716 recipients given either by use of --recipient or by the asked 1717 user id. No trust checking is performed for these user ids and 1718 even disabled keys can be used. 1719 --hidden-encrypt-to name 1722 Same as --hidden-recipient but this one is intended for use in 1723 the options file and may be used with your own user-id as a hid‐ 1724 den "encrypt-to-self". These keys are only used when there are 1725 other recipients given either by use of --recipient or by the 1726 asked user id. No trust checking is performed for these user 1727 ids and even disabled keys can be used. 1728 --no-encrypt-to 1731 Disable the use of all --encrypt-to and --hidden-encrypt-to 1732 keys. 1733 --group name=value1 1736 Sets up a named group, which is similar to aliases in email pro‐ 1737 grams. Any time the group name is a recipient (-r or --recipi‐ 1738 ent), it will be expanded to the values specified. Multiple 1739 groups with the same name are automatically merged into a single 1740 group. 1741 The values are key IDs or fingerprints, but any key description 1743 is accepted. Note that a value with spaces in it will be treated 1744 as two different values. Note also there is only one level of 1745 expansion --- you cannot make an group that points to another 1746 group. When used from the command line, it may be necessary to 1747 quote the argument to this option to prevent the shell from 1748 treating it as multiple arguments. 1749 --ungroup name 1752 Remove a given entry from the --group list. 1753 --no-groups 1756 Remove all entries from the --group list. 1757 --local-user name 1760 -u Use name as the key to sign with. Note that this option over‐ 1762 rides --default-key. 1763 --try-secret-key name 1766 For hidden recipients GPG needs to know the keys to use for 1767 trial decryption. The key set with --default-key is always 1768 tried first, but this is often not sufficient. This option 1769 allows to set more keys to be used for trial decryption. 1770 Although any valid user-id specification may be used for name it 1771 makes sense to use at least the long keyid to avoid ambiguities. 1772 Note that gpg-agent might pop up a pinentry for a lot keys to do 1773 the trial decryption. If you want to stop all further trial 1774 decryption you may use close-window button instead of the cancel 1775 button. 1776 --try-all-secrets 1779 Don't look at the key ID as stored in the message but try all 1780 secret keys in turn to find the right decryption key. This 1781 option forces the behaviour as used by anonymous recipients 1782 (created by using --throw-keyids or --hidden-recipient) and 1783 might come handy in case where an encrypted message contains a 1784 bogus key ID. 1785 --skip-hidden-recipients 1788 --no-skip-hidden-recipients 1790 During decryption skip all anonymous recipients. This option 1791 helps in the case that people use the hidden recipients feature 1792 to hide there own encrypt-to key from others. If oneself has 1793 many secret keys this may lead to a major annoyance because all 1794 keys are tried in turn to decrypt soemthing which was not really 1795 intended for it. The drawback of this option is that it is cur‐ 1796 rently not possible to decrypt a message which includes real 1797 anonymous recipients. 1798 Input and Output 1804 --armor 1809 -a Create ASCII armored output. The default is to create the 1811 binary OpenPGP format. 1812 --no-armor 1815 Assume the input data is not in ASCII armored format. 1816 --output file 1819 -o file 1821 Write output to file. 1822 --max-output n 1825 This option sets a limit on the number of bytes that will be 1826 generated when processing a file. Since OpenPGP supports various 1827 levels of compression, it is possible that the plaintext of a 1828 given message may be significantly larger than the original 1829 OpenPGP message. While GnuPG works properly with such messages, 1830 there is often a desire to set a maximum file size that will be 1831 generated before processing is forced to stop by the OS limits. 1832 Defaults to 0, which means "no limit". 1833 --import-options parameters 1836 This is a space or comma delimited string that gives options for 1837 importing keys. Options can be prepended with a `no-' to give 1838 the opposite meaning. The options are: 1839 import-local-sigs 1843 Allow importing key signatures marked as "local". This is 1844 not generally useful unless a shared keyring scheme is 1845 being used. Defaults to no. 1846 repair-pks-subkey-bug 1849 During import, attempt to repair the damage caused by the 1850 PKS keyserver bug (pre version 0.9.6) that mangles keys 1851 with multiple subkeys. Note that this cannot completely 1852 repair the damaged key as some crucial data is removed by 1853 the keyserver, but it does at least give you back one 1854 subkey. Defaults to no for regular --import and to yes 1855 for keyserver --recv-keys. 1856 merge-only 1859 During import, allow key updates to existing keys, but do 1860 not allow any new keys to be imported. Defaults to no. 1861 import-clean 1864 After import, compact (remove all signatures except the 1865 self-signature) any user IDs from the new key that are 1866 not usable. Then, remove any signatures from the new key 1867 that are not usable. This includes signatures that were 1868 issued by keys that are not present on the keyring. This 1869 option is the same as running the --edit-key command 1870 "clean" after import. Defaults to no. 1871 import-minimal 1874 Import the smallest key possible. This removes all signa‐ 1875 tures except the most recent self-signature on each user 1876 ID. This option is the same as running the --edit-key 1877 command "minimize" after import. Defaults to no. 1878 --export-options parameters 1881 This is a space or comma delimited string that gives options for 1882 exporting keys. Options can be prepended with a `no-' to give 1883 the opposite meaning. The options are: 1884 export-local-sigs 1888 Allow exporting key signatures marked as "local". This is 1889 not generally useful unless a shared keyring scheme is 1890 being used. Defaults to no. 1891 export-attributes 1894 Include attribute user IDs (photo IDs) while exporting. 1895 This is useful to export keys if they are going to be 1896 used by an OpenPGP program that does not accept attribute 1897 user IDs. Defaults to yes. 1898 export-sensitive-revkeys 1901 Include designated revoker information that was marked as 1902 "sensitive". Defaults to no. 1903 export-reset-subkey-passwd 1906 When using the --export-secret-subkeys command, this 1907 option resets the passphrases for all exported subkeys to 1908 empty. This is useful when the exported subkey is to be 1909 used on an unattended machine where a passphrase doesn't 1910 necessarily make sense. Defaults to no. 1911 export-clean 1914 Compact (remove all signatures from) user IDs on the key 1915 being exported if the user IDs are not usable. Also, do 1916 not export any signatures that are not usable. This 1917 includes signatures that were issued by keys that are not 1918 present on the keyring. This option is the same as run‐ 1919 ning the --edit-key command "clean" before export except 1920 that the local copy of the key is not modified. Defaults 1921 to no. 1922 export-minimal 1925 Export the smallest key possible. This removes all signa‐ 1926 tures except the most recent self-signature on each user 1927 ID. This option is the same as running the --edit-key 1928 command "minimize" before export except that the local 1929 copy of the key is not modified. Defaults to no. 1930 --with-colons 1933 Print key listings delimited by colons. Note that the output 1934 will be encoded in UTF-8 regardless of any --display-charset 1935 setting. This format is useful when GnuPG is called from scripts 1936 and other programs as it is easily machine parsed. The details 1937 of this format are documented in the file ‘doc/DETAILS’, which 1938 is included in the GnuPG source distribution. 1939 --fixed-list-mode 1942 Do not merge primary user ID and primary key in --with-colon 1943 listing mode and print all timestamps as seconds since 1944 1970-01-01. Since GnuPG 2.0.10, this mode is always used and 1945 thus this option is obsolete; it does not harm to use it though. 1946 --with-fingerprint 1949 Same as the command --fingerprint but changes only the format of 1950 the output and may be used together with another command. 1951 --with-keygrip 1954 Include the keygrip in the key listings. 1955 OpenPGP protocol specific options. 1960 -t, --textmode 1965 --no-textmode 1967 Treat input files as text and store them in the OpenPGP canoni‐ 1968 cal text form with standard "CRLF" line endings. This also sets 1969 the necessary flags to inform the recipient that the encrypted 1970 or signed data is text and may need its line endings converted 1971 back to whatever the local system uses. This option is useful 1972 when communicating between two platforms that have different 1973 line ending conventions (UNIX-like to Mac, Mac to Windows, etc). 1974 --no-textmode disables this option, and is the default. 1975 --force-v3-sigs 1979 --no-force-v3-sigs 1981 OpenPGP states that an implementation should generate v4 signa‐ 1982 tures but PGP versions 5 through 7 only recognize v4 signatures 1983 on key material. This option forces v3 signatures for signatures 1984 on data. Note that this option implies --no-ask-sig-expire, and 1985 unsets --sig-policy-url, --sig-notation, and --sig-keyserver- 1986 url, as these features cannot be used with v3 signatures. --no- 1987 force-v3-sigs disables this option. Defaults to no. 1988 --force-v4-certs 1991 --no-force-v4-certs 1993 Always use v4 key signatures even on v3 keys. This option also 1994 changes the default hash algorithm for v3 RSA keys from MD5 to 1995 SHA-1. --no-force-v4-certs disables this option. 1996 --force-mdc 1999 Force the use of encryption with a modification detection code. 2000 This is always used with the newer ciphers (those with a block‐ 2001 size greater than 64 bits), or if all of the recipient keys 2002 indicate MDC support in their feature flags. 2003 --disable-mdc 2006 Disable the use of the modification detection code. Note that by 2007 using this option, the encrypted message becomes vulnerable to a 2008 message modification attack. 2009 --personal-cipher-preferences string 2012 Set the list of personal cipher preferences to string. Use gpg2 2013 --version to get a list of available algorithms, and use none to 2014 set no preference at all. This allows the user to safely over‐ 2015 ride the algorithm chosen by the recipient key preferences, as 2016 GPG will only select an algorithm that is usable by all recipi‐ 2017 ents. The most highly ranked cipher in this list is also used 2018 for the --symmetric encryption command. 2019 --personal-digest-preferences string 2022 Set the list of personal digest preferences to string. Use gpg2 2023 --version to get a list of available algorithms, and use none to 2024 set no preference at all. This allows the user to safely over‐ 2025 ride the algorithm chosen by the recipient key preferences, as 2026 GPG will only select an algorithm that is usable by all recipi‐ 2027 ents. The most highly ranked digest algorithm in this list is 2028 also used when signing without encryption (e.g. --clearsign or 2029 --sign). 2030 --personal-compress-preferences string 2033 Set the list of personal compression preferences to string. Use 2034 gpg2 --version to get a list of available algorithms, and use 2035 none to set no preference at all. This allows the user to 2036 safely override the algorithm chosen by the recipient key pref‐ 2037 erences, as GPG will only select an algorithm that is usable by 2038 all recipients. The most highly ranked compression algorithm in 2039 this list is also used when there are no recipient keys to con‐ 2040 sider (e.g. --symmetric). 2041 --s2k-cipher-algo name 2044 Use name as the cipher algorithm used to protect secret keys. 2045 The default cipher is CAST5. This cipher is also used for con‐ 2046 ventional encryption if --personal-cipher-preferences and 2047 --cipher-algo is not given. 2048 --s2k-digest-algo name 2051 Use name as the digest algorithm used to mangle the passphrases. 2052 The default algorithm is SHA-1. 2053 --s2k-mode n 2056 Selects how passphrases are mangled. If n is 0 a plain 2057 passphrase (which is not recommended) will be used, a 1 adds a 2058 salt to the passphrase and a 3 (the default) iterates the whole 2059 process a number of times (see --s2k-count). Unless --rfc1991 2060 is used, this mode is also used for conventional encryption. 2061 --s2k-count n 2064 Specify how many times the passphrase mangling is repeated. 2065 This value may range between 1024 and 65011712 inclusive. The 2066 default is inquired from gpg-agent. Note that not all values in 2067 the 1024-65011712 range are legal and if an illegal value is 2068 selected, GnuPG will round up to the nearest legal value. This 2069 option is only meaningful if --s2k-mode is 3. 2070 Compliance options 2076 These options control what GnuPG is compliant to. Only one of these 2079 options may be active at a time. Note that the default setting of this 2080 is nearly always the correct one. See the INTEROPERABILITY WITH OTHER 2081 OPENPGP PROGRAMS section below before using one of these options. 2082 --gnupg 2086 Use standard GnuPG behavior. This is essentially OpenPGP behav‐ 2087 ior (see --openpgp), but with some additional workarounds for 2088 common compatibility problems in different versions of PGP. This 2089 is the default option, so it is not generally needed, but it may 2090 be useful to override a different compliance option in the 2091 gpg.conf file. 2092 --openpgp 2095 Reset all packet, cipher and digest options to strict OpenPGP 2096 behavior. Use this option to reset all previous options like 2097 --s2k-*, --cipher-algo, --digest-algo and --compress-algo to 2098 OpenPGP compliant values. All PGP workarounds are disabled. 2099 --rfc4880 2102 Reset all packet, cipher and digest options to strict RFC-4880 2103 behavior. Note that this is currently the same thing as 2104 --openpgp. 2105 --rfc2440 2108 Reset all packet, cipher and digest options to strict RFC-2440 2109 behavior. 2110 --rfc1991 2113 Try to be more RFC-1991 (PGP 2.x) compliant. 2114 --pgp2 Set up all options to be as PGP 2.x compliant as possible, and 2117 warn if an action is taken (e.g. encrypting to a non-RSA key) 2118 that will create a message that PGP 2.x will not be able to han‐ 2119 dle. Note that `PGP 2.x' here means `MIT PGP 2.6.2'. There are 2120 other versions of PGP 2.x available, but the MIT release is a 2121 good common baseline. 2122 This option implies --rfc1991 --disable-mdc --no-force-v4-certs 2124 --escape-from-lines --force-v3-sigs --cipher-algo IDEA --digest- 2125 algo MD5 --compress-algo ZIP. It also disables --textmode when 2126 encrypting. 2127 --pgp6 Set up all options to be as PGP 6 compliant as possible. This 2130 restricts you to the ciphers IDEA (if the IDEA plugin is 2131 installed), 3DES, and CAST5, the hashes MD5, SHA1 and RIPEMD160, 2132 and the compression algorithms none and ZIP. This also disables 2133 --throw-keyids, and making signatures with signing subkeys as 2134 PGP 6 does not understand signatures made by signing subkeys. 2135 This option implies --disable-mdc --escape-from-lines --force- 2137 v3-sigs. 2138 --pgp7 Set up all options to be as PGP 7 compliant as possible. This is 2141 identical to --pgp6 except that MDCs are not disabled, and the 2142 list of allowable ciphers is expanded to add AES128, AES192, 2143 AES256, and TWOFISH. 2144 --pgp8 Set up all options to be as PGP 8 compliant as possible. PGP 8 2147 is a lot closer to the OpenPGP standard than previous versions 2148 of PGP, so all this does is disable --throw-keyids and set 2149 --escape-from-lines. All algorithms are allowed except for the 2150 SHA224, SHA384, and SHA512 digests. 2151 Doing things one usually doesn't want to do. 2157 -n 2162 --dry-run 2164 Don't make any changes (this is not completely implemented). 2165 --list-only 2168 Changes the behaviour of some commands. This is like --dry-run 2169 but different in some cases. The semantic of this command may be 2170 extended in the future. Currently it only skips the actual 2171 decryption pass and therefore enables a fast listing of the 2172 encryption keys. 2173 -i 2176 --interactive 2178 Prompt before overwriting any files. 2179 --debug-level level 2182 Select the debug level for investigating problems. level may be 2183 a numeric value or by a keyword: 2184 none No debugging at all. A value of less than 1 may be used 2187 instead of the keyword. 2188 basic Some basic debug messages. A value between 1 and 2 may 2190 be used instead of the keyword. 2191 advanced 2193 More verbose debug messages. A value between 3 and 5 may 2194 be used instead of the keyword. 2195 expert Even more detailed messages. A value between 6 and 8 may 2197 be used instead of the keyword. 2198 guru All of the debug messages you can get. A value greater 2200 than 8 may be used instead of the keyword. The creation 2201 of hash tracing files is only enabled if the keyword is 2202 used. 2203 How these messages are mapped to the actual debugging flags is not 2205 specified and may change with newer releases of this program. They are 2206 however carefully selected to best aid in debugging. 2207 --debug flags 2210 Set debugging flags. All flags are or-ed and flags may be given 2211 in C syntax (e.g. 0x0042). 2212 --debug-all 2215 Set all useful debugging flags. 2216 --faked-system-time epoch 2220 This option is only useful for testing; it sets the system time 2221 back or forth to epoch which is the number of seconds elapsed 2222 since the year 1970. Alternatively epoch may be given as a full 2223 ISO time string (e.g. "20070924T154812"). 2224 --enable-progress-filter 2227 Enable certain PROGRESS status outputs. This option allows fron‐ 2228 tends to display a progress indicator while gpg is processing 2229 larger files. There is a slight performance overhead using it. 2230 --status-fd n 2233 Write special status strings to the file descriptor n. See the 2234 file DETAILS in the documentation for a listing of them. 2235 --status-file file 2238 Same as --status-fd, except the status data is written to file 2239 file. 2240 --logger-fd n 2243 Write log output to file descriptor n and not to STDERR. 2244 --log-file file 2247 --logger-file file 2249 Same as --logger-fd, except the logger data is written to file 2250 file. Note that --log-file is only implemented for GnuPG-2. 2251 --attribute-fd n 2254 Write attribute subpackets to the file descriptor n. This is 2255 most useful for use with --status-fd, since the status messages 2256 are needed to separate out the various subpackets from the 2257 stream delivered to the file descriptor. 2258 --attribute-file file 2261 Same as --attribute-fd, except the attribute data is written to 2262 file file. 2263 --comment string 2266 --no-comments 2268 Use string as a comment string in clear text signatures and 2269 ASCII armored messages or keys (see --armor). The default behav‐ 2270 ior is not to use a comment string. --comment may be repeated 2271 multiple times to get multiple comment strings. --no-comments 2272 removes all comments. It is a good idea to keep the length of a 2273 single comment below 60 characters to avoid problems with mail 2274 programs wrapping such lines. Note that comment lines, like all 2275 other header lines, are not protected by the signature. 2276 --emit-version 2279 --no-emit-version 2281 Force inclusion of the version string in ASCII armored output. 2282 --no-emit-version disables this option. 2283 --sig-notation name=value 2286 --cert-notation name=value 2288 -N, --set-notation name=value 2290 Put the name value pair into the signature as notation data. 2291 name must consist only of printable characters or spaces, and 2292 must contain a '@' character in the form keyname@domain.exam‐ 2293 ple.com (substituting the appropriate keyname and domain name, 2294 of course). This is to help prevent pollution of the IETF 2295 reserved notation namespace. The --expert flag overrides the '@' 2296 check. value may be any printable string; it will be encoded in 2297 UTF8, so you should check that your --display-charset is set 2298 correctly. If you prefix name with an exclamation mark (!), the 2299 notation data will be flagged as critical (rfc4880:5.2.3.16). 2300 --sig-notation sets a notation for data signatures. --cert-nota‐ 2301 tion sets a notation for key signatures (certifications). --set- 2302 notation sets both. 2303 There are special codes that may be used in notation names. "%k" 2305 will be expanded into the key ID of the key being signed, "%K" 2306 into the long key ID of the key being signed, "%f" into the fin‐ 2307 gerprint of the key being signed, "%s" into the key ID of the 2308 key making the signature, "%S" into the long key ID of the key 2309 making the signature, "%g" into the fingerprint of the key mak‐ 2310 ing the signature (which might be a subkey), "%p" into the fin‐ 2311 gerprint of the primary key of the key making the signature, 2312 "%c" into the signature count from the OpenPGP smartcard, and 2313 "%%" results in a single "%". %k, %K, and %f are only meaningful 2314 when making a key signature (certification), and %c is only 2315 meaningful when using the OpenPGP smartcard. 2316 --sig-policy-url string 2319 --cert-policy-url string 2321 --set-policy-url string 2323 Use string as a Policy URL for signatures (rfc4880:5.2.3.20). 2324 If you prefix it with an exclamation mark (!), the policy URL 2325 packet will be flagged as critical. --sig-policy-url sets a pol‐ 2326 icy url for data signatures. --cert-policy-url sets a policy url 2327 for key signatures (certifications). --set-policy-url sets both. 2328 The same %-expandos used for notation data are available here as 2330 well. 2331 --sig-keyserver-url string 2334 Use string as a preferred keyserver URL for data signatures. If 2335 you prefix it with an exclamation mark (!), the keyserver URL 2336 packet will be flagged as critical. 2337 The same %-expandos used for notation data are available here as 2339 well. 2340 --set-filename string 2343 Use string as the filename which is stored inside messages. 2344 This overrides the default, which is to use the actual filename 2345 of the file being encrypted. 2346 --for-your-eyes-only 2349 --no-for-your-eyes-only 2351 Set the `for your eyes only' flag in the message. This causes 2352 GnuPG to refuse to save the file unless the --output option is 2353 given, and PGP to use a "secure viewer" with a claimed Tempest- 2354 resistant font to display the message. This option overrides 2355 --set-filename. --no-for-your-eyes-only disables this option. 2356 --use-embedded-filename 2359 --no-use-embedded-filename 2361 Try to create a file with a name as embedded in the data. This 2362 can be a dangerous option as it allows to overwrite files. 2363 Defaults to no. 2364 --cipher-algo name 2367 Use name as cipher algorithm. Running the program with the com‐ 2368 mand --version yields a list of supported algorithms. If this is 2369 not used the cipher algorithm is selected from the preferences 2370 stored with the key. In general, you do not want to use this 2371 option as it allows you to violate the OpenPGP standard. --per‐ 2372 sonal-cipher-preferences is the safe way to accomplish the same 2373 thing. 2374 --digest-algo name 2377 Use name as the message digest algorithm. Running the program 2378 with the command --version yields a list of supported algo‐ 2379 rithms. In general, you do not want to use this option as it 2380 allows you to violate the OpenPGP standard. --personal-digest- 2381 preferences is the safe way to accomplish the same thing. 2382 --compress-algo name 2385 Use compression algorithm name. "zlib" is RFC-1950 ZLIB compres‐ 2386 sion. "zip" is RFC-1951 ZIP compression which is used by PGP. 2387 "bzip2" is a more modern compression scheme that can compress 2388 some things better than zip or zlib, but at the cost of more 2389 memory used during compression and decompression. "uncompressed" 2390 or "none" disables compression. If this option is not used, the 2391 default behavior is to examine the recipient key preferences to 2392 see which algorithms the recipient supports. If all else fails, 2393 ZIP is used for maximum compatibility. 2394 ZLIB may give better compression results than ZIP, as the com‐ 2396 pression window size is not limited to 8k. BZIP2 may give even 2397 better compression results than that, but will use a signifi‐ 2398 cantly larger amount of memory while compressing and decompress‐ 2399 ing. This may be significant in low memory situations. Note, 2400 however, that PGP (all versions) only supports ZIP compression. 2401 Using any algorithm other than ZIP or "none" will make the mes‐ 2402 sage unreadable with PGP. In general, you do not want to use 2403 this option as it allows you to violate the OpenPGP standard. 2404 --personal-compress-preferences is the safe way to accomplish 2405 the same thing. 2406 --cert-digest-algo name 2409 Use name as the message digest algorithm used when signing a 2410 key. Running the program with the command --version yields a 2411 list of supported algorithms. Be aware that if you choose an 2412 algorithm that GnuPG supports but other OpenPGP implementations 2413 do not, then some users will not be able to use the key signa‐ 2414 tures you make, or quite possibly your entire key. 2415 --disable-cipher-algo name 2418 Never allow the use of name as cipher algorithm. The given name 2419 will not be checked so that a later loaded algorithm will still 2420 get disabled. 2421 --disable-pubkey-algo name 2424 Never allow the use of name as public key algorithm. The given 2425 name will not be checked so that a later loaded algorithm will 2426 still get disabled. 2427 --throw-keyids 2430 --no-throw-keyids 2432 Do not put the recipient key IDs into encrypted messages. This 2433 helps to hide the receivers of the message and is a limited 2434 countermeasure against traffic analysis. ([Using a little social 2435 engineering anyone who is able to decrypt the message can check 2436 whether one of the other recipients is the one he suspects.]) 2437 On the receiving side, it may slow down the decryption process 2438 because all available secret keys must be tried. --no-throw- 2439 keyids disables this option. This option is essentially the same 2440 as using --hidden-recipient for all recipients. 2441 --not-dash-escaped 2444 This option changes the behavior of cleartext signatures so that 2445 they can be used for patch files. You should not send such an 2446 armored file via email because all spaces and line endings are 2447 hashed too. You can not use this option for data which has 5 2448 dashes at the beginning of a line, patch files don't have this. 2449 A special armor header line tells GnuPG about this cleartext 2450 signature option. 2451 --escape-from-lines 2454 --no-escape-from-lines 2456 Because some mailers change lines starting with "From " to 2457 ">From " it is good to handle such lines in a special way when 2458 creating cleartext signatures to prevent the mail system from 2459 breaking the signature. Note that all other PGP versions do it 2460 this way too. Enabled by default. --no-escape-from-lines dis‐ 2461 ables this option. 2462 --passphrase-repeat n 2465 Specify how many times gpg2 will request a new passphrase be 2466 repeated. This is useful for helping memorize a passphrase. 2467 Defaults to 1 repetition. 2468 --passphrase-fd n 2471 Read the passphrase from file descriptor n. Only the first line 2472 will be read from file descriptor n. If you use 0 for n, the 2473 passphrase will be read from STDIN. This can only be used if 2474 only one passphrase is supplied. Note that this passphrase is 2475 only used if the option --batch has also been given. This is 2476 different from gpg. 2477 --passphrase-file file 2480 Read the passphrase from file file. Only the first line will be 2481 read from file file. This can only be used if only one 2482 passphrase is supplied. Obviously, a passphrase stored in a file 2483 is of questionable security if other users can read this file. 2484 Don't use this option if you can avoid it. Note that this 2485 passphrase is only used if the option --batch has also been 2486 given. This is different from gpg. 2487 --passphrase string 2490 Use string as the passphrase. This can only be used if only one 2491 passphrase is supplied. Obviously, this is of very questionable 2492 security on a multi-user system. Don't use this option if you 2493 can avoid it. Note that this passphrase is only used if the 2494 option --batch has also been given. This is different from gpg. 2495 --pinentry-mode mode 2498 Set the pinentry mode to mode. Allowed values for mode are: 2499 default 2501 Use the default of the agent, which is ask. 2502 ask Force the use of the Pinentry. 2504 cancel Emulate use of Pinentry's cancel button. 2506 error Return a Pinentry error (``No Pinentry''). 2508 loopback 2510 Redirect Pinentry queries to the caller. Note that in 2511 contrast to Pinentry the user is not prompted again if he 2512 enters a bad password. 2513 --command-fd n 2516 This is a replacement for the deprecated shared-memory IPC mode. 2517 If this option is enabled, user input on questions is not 2518 expected from the TTY but from the given file descriptor. It 2519 should be used together with --status-fd. See the file 2520 doc/DETAILS in the source distribution for details on how to use 2521 it. 2522 --command-file file 2525 Same as --command-fd, except the commands are read out of file 2526 file 2527 --allow-non-selfsigned-uid 2530 --no-allow-non-selfsigned-uid 2532 Allow the import and use of keys with user IDs which are not 2533 self-signed. This is not recommended, as a non self-signed user 2534 ID is trivial to forge. --no-allow-non-selfsigned-uid disables. 2535 --allow-freeform-uid 2538 Disable all checks on the form of the user ID while generating a 2539 new one. This option should only be used in very special envi‐ 2540 ronments as it does not ensure the de-facto standard format of 2541 user IDs. 2542 --ignore-time-conflict 2545 GnuPG normally checks that the timestamps associated with keys 2546 and signatures have plausible values. However, sometimes a sig‐ 2547 nature seems to be older than the key due to clock problems. 2548 This option makes these checks just a warning. See also 2549 --ignore-valid-from for timestamp issues on subkeys. 2550 --ignore-valid-from 2553 GnuPG normally does not select and use subkeys created in the 2554 future. This option allows the use of such keys and thus 2555 exhibits the pre-1.0.7 behaviour. You should not use this option 2556 unless there is some clock problem. See also --ignore-time-con‐ 2557 flict for timestamp issues with signatures. 2558 --ignore-crc-error 2561 The ASCII armor used by OpenPGP is protected by a CRC checksum 2562 against transmission errors. Occasionally the CRC gets mangled 2563 somewhere on the transmission channel but the actual content 2564 (which is protected by the OpenPGP protocol anyway) is still 2565 okay. This option allows GnuPG to ignore CRC errors. 2566 --ignore-mdc-error 2569 This option changes a MDC integrity protection failure into a 2570 warning. This can be useful if a message is partially corrupt, 2571 but it is necessary to get as much data as possible out of the 2572 corrupt message. However, be aware that a MDC protection fail‐ 2573 ure may also mean that the message was tampered with intention‐ 2574 ally by an attacker. 2575 --no-default-keyring 2578 Do not add the default keyrings to the list of keyrings. Note 2579 that GnuPG will not operate without any keyrings, so if you use 2580 this option and do not provide alternate keyrings via --keyring 2581 or --secret-keyring, then GnuPG will still use the default pub‐ 2582 lic or secret keyrings. 2583 --skip-verify 2586 Skip the signature verification step. This may be used to make 2587 the decryption faster if the signature verification is not 2588 needed. 2589 --with-key-data 2592 Print key listings delimited by colons (like --with-colons) and 2593 print the public key data. 2594 --fast-list-mode 2597 Changes the output of the list commands to work faster; this is 2598 achieved by leaving some parts empty. Some applications don't 2599 need the user ID and the trust information given in the list‐ 2600 ings. By using this options they can get a faster listing. The 2601 exact behaviour of this option may change in future versions. 2602 If you are missing some information, don't use this option. 2603 --no-literal 2606 This is not for normal use. Use the source to see for what it 2607 might be useful. 2608 --set-filesize 2611 This is not for normal use. Use the source to see for what it 2612 might be useful. 2613 --show-session-key 2616 Display the session key used for one message. See --override- 2617 session-key for the counterpart of this option. 2618 We think that Key Escrow is a Bad Thing; however the user should 2620 have the freedom to decide whether to go to prison or to reveal 2621 the content of one specific message without compromising all 2622 messages ever encrypted for one secret key. DON'T USE IT UNLESS 2623 YOU ARE REALLY FORCED TO DO SO. 2624 --override-session-key string 2627 Don't use the public key but the session key string. The format 2628 of this string is the same as the one printed by --show-session- 2629 key. This option is normally not used but comes handy in case 2630 someone forces you to reveal the content of an encrypted mes‐ 2631 sage; using this option you can do this without handing out the 2632 secret key. 2633 --ask-sig-expire 2636 --no-ask-sig-expire 2638 When making a data signature, prompt for an expiration time. If 2639 this option is not specified, the expiration time set via 2640 --default-sig-expire is used. --no-ask-sig-expire disables this 2641 option. 2642 --default-sig-expire 2645 The default expiration time to use for signature expiration. 2646 Valid values are "0" for no expiration, a number followed by the 2647 letter d (for days), w (for weeks), m (for months), or y (for 2648 years) (for example "2m" for two months, or "5y" for five 2649 years), or an absolute date in the form YYYY-MM-DD. Defaults to 2650 "0". 2651 --ask-cert-expire 2654 --no-ask-cert-expire 2656 When making a key signature, prompt for an expiration time. If 2657 this option is not specified, the expiration time set via 2658 --default-cert-expire is used. --no-ask-cert-expire disables 2659 this option. 2660 --default-cert-expire 2663 The default expiration time to use for key signature expiration. 2664 Valid values are "0" for no expiration, a number followed by the 2665 letter d (for days), w (for weeks), m (for months), or y (for 2666 years) (for example "2m" for two months, or "5y" for five 2667 years), or an absolute date in the form YYYY-MM-DD. Defaults to 2668 "0". 2669 --allow-secret-key-import 2672 This is an obsolete option and is not used anywhere. 2673 --allow-multiple-messages 2676 --no-allow-multiple-messages 2678 Allow processing of multiple OpenPGP messages contained in a 2679 single file or stream. Some programs that call GPG are not pre‐ 2680 pared to deal with multiple messages being processed together, 2681 so this option defaults to no. Note that versions of GPG prior 2682 to 1.4.7 always allowed multiple messages. 2683 Warning: Do not use this option unless you need it as a tempo‐ 2685 rary workaround! 2686 --enable-special-filenames 2690 This options enables a mode in which filenames of the form 2691 ‘-&n’, where n is a non-negative decimal number, refer to the 2692 file descriptor n and not to a file with that name. 2693 --no-expensive-trust-checks 2696 Experimental use only. 2697 --preserve-permissions 2700 Don't change the permissions of a secret keyring back to user 2701 read/write only. Use this option only if you really know what 2702 you are doing. 2703 --default-preference-list string 2706 Set the list of default preferences to string. This preference 2707 list is used for new keys and becomes the default for "setpref" 2708 in the edit menu. 2709 --default-keyserver-url name 2712 Set the default keyserver URL to name. This keyserver will be 2713 used as the keyserver URL when writing a new self-signature on a 2714 key, which includes key generation and changing preferences. 2715 --list-config 2718 Display various internal configuration parameters of GnuPG. This 2719 option is intended for external programs that call GnuPG to per‐ 2720 form tasks, and is thus not generally useful. See the file 2721 ‘doc/DETAILS’ in the source distribution for the details of 2722 which configuration items may be listed. --list-config is only 2723 usable with --with-colons set. 2724 --gpgconf-list 2727 This command is similar to --list-config but in general only 2728 internally used by the gpgconf tool. 2729 --gpgconf-test 2732 This is more or less dummy action. However it parses the con‐ 2733 figuration file and returns with failure if the configuration 2734 file would prevent gpg from startup. Thus it may be used to run 2735 a syntax check on the configuration file. 2736 Deprecated options 2741 --show-photos 2747 --no-show-photos 2749 Causes --list-keys, --list-sigs, --list-public-keys, --list- 2750 secret-keys, and verifying a signature to also display the photo 2751 ID attached to the key, if any. See also --photo-viewer. These 2752 options are deprecated. Use --list-options [no-]show-photos 2753 and/or --verify-options [no-]show-photos instead. 2754 --show-keyring 2757 Display the keyring name at the head of key listings to show 2758 which keyring a given key resides on. This option is deprecated: 2759 use --list-options [no-]show-keyring instead. 2760 --always-trust 2764 Identical to --trust-model always. This option is deprecated. 2765 --show-notation 2768 --no-show-notation 2770 Show signature notations in the --list-sigs or --check-sigs 2771 listings as well as when verifying a signature with a notation 2772 in it. These options are deprecated. Use --list-options 2773 [no-]show-notation and/or --verify-options [no-]show-notation 2774 instead. 2775 --show-policy-url 2778 --no-show-policy-url 2780 Show policy URLs in the --list-sigs or --check-sigs listings as 2781 well as when verifying a signature with a policy URL in it. 2782 These options are deprecated. Use --list-options [no-]show-pol‐ 2783 icy-url and/or --verify-options [no-]show-policy-url instead. 2784
2791 gpg -se -r Bob file 2792 sign and encrypt for user Bob 2793 gpg --clearsign file 2796 make a clear text signature 2797 gpg -sb file 2800 make a detached signature 2801 gpg -u 0x12345678 -sb file 2804 make a detached signature with the key 0x12345678 2805 gpg --list-keys user_ID 2808 show keys 2809 gpg --fingerprint user_ID 2812 show fingerprint 2813 gpg --verify pgpfile 2816 gpg --verify sigfile 2818 Verify the signature of the file but do not output the data. The 2819 second form is used for detached signatures, where sigfile is 2820 the detached signature (either ASCII armored or binary) and are 2821 the signed data; if this is not given, the name of the file 2822 holding the signed data is constructed by cutting off the exten‐ 2823 sion (".asc" or ".sig") of sigfile or by asking the user for the 2824 filename. 2825
2830 There are different ways to specify a user ID to GnuPG. Some of them 2831 are only valid for gpg others are only good for gpgsm. Here is the 2832 entire list of ways to specify a key: 2833 By key Id. 2837 This format is deduced from the length of the string and its 2838 content or 0x prefix. The key Id of an X.509 certificate are the 2839 low 64 bits of its SHA-1 fingerprint. The use of key Ids is 2840 just a shortcut, for all automated processing the fingerprint 2841 should be used. 2842 When using gpg an exclamation mark (!) may be appended to force 2844 using the specified primary or secondary key and not to try and 2845 calculate which primary or secondary key to use. 2846 The last four lines of the example give the key ID in their long 2848 form as internally used by the OpenPGP protocol. You can see the 2849 long key ID using the option --with-colons. 2850 234567C4 2852 0F34E556E 2853 01347A56A 2854 0xAB123456 2855 234AABBCC34567C4 2857 0F323456784E56EAB 2858 01AB3FED1347A5612 2859 0x234AABBCC34567C4 2860 By fingerprint. 2865 This format is deduced from the length of the string and its 2866 content or the 0x prefix. Note, that only the 20 byte version 2867 fingerprint is available with gpgsm (i.e. the SHA-1 hash of the 2868 certificate). 2869 When using gpg an exclamation mark (!) may be appended to force 2871 using the specified primary or secondary key and not to try and 2872 calculate which primary or secondary key to use. 2873 The best way to specify a key Id is by using the fingerprint. 2875 This avoids any ambiguities in case that there are duplicated 2876 key IDs. 2877 1234343434343434C434343434343434 2879 123434343434343C3434343434343734349A3434 2880 0E12343434343434343434EAB3484343434343434 2881 0xE12343434343434343434EAB3484343434343434 2882 (gpgsm also accepts colons between each pair of hexadecimal digits 2885 because this is the de-facto standard on how to present X.509 finger‐ 2886 prints.) 2887 By exact match on OpenPGP user ID. 2890 This is denoted by a leading equal sign. It does not make sense 2891 for X.509 certificates. 2892 =Heinrich Heine <heinrichh@uni-duesseldorf.de> 2894 By exact match on an email address. 2897 This is indicated by enclosing the email address in the usual 2898 way with left and right angles. 2899 <heinrichh@uni-duesseldorf.de> 2901 By word match. 2905 All words must match exactly (not case sensitive) but can appear 2906 in any order in the user ID or a subjects name. Words are any 2907 sequences of letters, digits, the underscore and all characters 2908 with bit 7 set. 2909 +Heinrich Heine duesseldorf 2911 By exact match on the subject's DN. 2914 This is indicated by a leading slash, directly followed by the 2915 RFC-2253 encoded DN of the subject. Note that you can't use the 2916 string printed by "gpgsm --list-keys" because that one as been 2917 reordered and modified for better readability; use --with-colons 2918 to print the raw (but standard escaped) RFC-2253 string 2919 /CN=Heinrich Heine,O=Poets,L=Paris,C=FR 2921 By exact match on the issuer's DN. 2924 This is indicated by a leading hash mark, directly followed by a 2925 slash and then directly followed by the rfc2253 encoded DN of 2926 the issuer. This should return the Root cert of the issuer. 2927 See note above. 2928 #/CN=Root Cert,O=Poets,L=Paris,C=FR 2930 By exact match on serial number and issuer's DN. 2934 This is indicated by a hash mark, followed by the hexadecimal 2935 representation of the serial number, then followed by a slash 2936 and the RFC-2253 encoded DN of the issuer. See note above. 2937 #4F03/CN=Root Cert,O=Poets,L=Paris,C=FR 2939 By keygrip 2942 This is indicated by an ampersand followed by the 40 hex digits 2943 of a keygrip. gpgsm prints the keygrip when using the command 2944 --dump-cert. It does not yet work for OpenPGP keys. 2945 &D75F22C3F86E355877348498CDC92BD21010A480 2947 By substring match. 2951 This is the default mode but applications may want to explicitly 2952 indicate this by putting the asterisk in front. Match is not 2953 case sensitive. 2954 Heine 2956 *Heine 2957 Please note that we have reused the hash mark identifier which was used 2961 in old GnuPG versions to indicate the so called local-id. It is not 2962 anymore used and there should be no conflict when used with X.509 2963 stuff. 2964 Using the RFC-2253 format of DNs has the drawback that it is not possi‐ 2966 ble to map them back to the original encoding, however we don't have to 2967 do this because our key database stores this encoding as meta data. 2968
2974 There are a few configuration files to control certain aspects of 2975 gpg2's operation. Unless noted, they are expected in the current home 2976 directory (see: [option --homedir]). 2977 gpg.conf 2981 This is the standard configuration file read by gpg2 on startup. 2982 It may contain any valid long option; the leading two dashes may 2983 not be entered and the option may not be abbreviated. This 2984 default name may be changed on the command line (see: [gpg- 2985 option --options]). You should backup this file. 2986 Note that on larger installations, it is useful to put predefined files 2989 into the directory ‘/etc/skel/.gnupg/’ so that newly created users 2990 start up with a working configuration. For existing users the a small 2991 helper script is provided to create these files (see: [addgnupghome]). 2992 For internal purposes gpg2 creates and maintains a few other files; 2994 They all live in in the current home directory (see: [option --home‐ 2995 dir]). Only the gpg2 may modify these files. 2996 ~/.gnupg/secring.gpg 3000 The secret keyring. You should backup this file. 3001 ~/.gnupg/secring.gpg.lock 3004 The lock file for the secret keyring. 3005 ~/.gnupg/pubring.gpg 3008 The public keyring. You should backup this file. 3009 ~/.gnupg/pubring.gpg.lock 3012 The lock file for the public keyring. 3013 ~/.gnupg/trustdb.gpg 3016 The trust database. There is no need to backup this file; it is 3017 better to backup the ownertrust values (see: [option --export- 3018 ownertrust]). 3019 ~/.gnupg/trustdb.gpg.lock 3022 The lock file for the trust database. 3023 ~/.gnupg/random_seed 3026 A file used to preserve the state of the internal random pool. 3027 /usr[/local]/share/gnupg/options.skel 3030 The skeleton options file. 3031 /usr[/local]/lib/gnupg/ 3034 Default location for extensions. 3035 Operation is further controlled by a few environment variables: 3038 HOME Used to locate the default home directory. 3042 GNUPGHOME 3045 If set directory used instead of "~/.gnupg". 3046 GPG_AGENT_INFO 3049 Used to locate the gpg-agent. 3050 The value consists of 3 colon delimited fields: The first is 3051 the path 3052 to the Unix Domain Socket, the second the PID of the gpg-agent 3053 and the 3054 protocol version which should be set to 1. When starting the 3055 gpg-agent 3056 as described in its documentation, this variable is set to the 3057 correct 3058 value. The option --gpg-agent-info can be used to override it. 3059 PINENTRY_USER_DATA 3062 This value is passed via gpg-agent to pinentry. It is useful to 3063 convey extra information to a custom pinentry. 3064 COLUMNS 3067 LINES Used to size some displays to the full size of the screen. 3069 LANGUAGE 3073 Apart from its use by GNU, it is used in the W32 version to 3074 override the language selection done through the Registry. If 3075 used and set to a valid and available language name (langid), 3076 the file with the translation is loaded from 3077 gpgdir/gnupg.nls/langid.mo. Here gpgdir is the directory out of 3079 which the gpg binary has been loaded. If it can't be loaded the 3080 Registry is tried and as last resort the native Windows locale 3081 system is used. 3082
3088 On older systems this program should be installed as setuid(root). This 3089 is necessary to lock memory pages. Locking memory pages prevents the 3090 operating system from writing memory pages (which may contain 3091 passphrases or other sensitive material) to disk. If you get no warning 3092 message about insecure memory your operating system supports locking 3093 without being root. The program drops root privileges as soon as locked 3094 memory is allocated. 3095 Note also that some systems (especially laptops) have the ability to 3097 ``suspend to disk'' (also known as ``safe sleep'' or ``hibernate''). 3098 This writes all memory to disk before going into a low power or even 3099 powered off mode. Unless measures are taken in the operating system to 3100 protect the saved memory, passphrases or other sensitive material may 3101 be recoverable from it later. 3102 Before you report a bug you should first search the mailing list ar‐ 3104 chives for similar problems and second check whether such a bug has 3105 already been reported to our bug tracker at http://bugs.gnupg.org . 3106
3110 gpgv(1), gpgsm(1), gpg-agent(1) 3111 The full documentation for this tool is maintained as a Texinfo manual. 3113 If GnuPG and the info program are properly installed at your site, the 3114 command 3115 info gnupg 3117 should give you access to the complete manual including a menu struc‐ 3119 ture and an index. 3120GnuPG 2.0.22 2018-07-13 GPG2(1)