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GPG2(1)                                           GNU Privacy Guard                                           GPG2(1)



NAME
       gpg2 - OpenPGP encryption and signing tool

SYNOPSIS
       gpg2 [--homedir dir] [--options file] [options] command [args]


DESCRIPTION
       gpg2  is  the  OpenPGP  part  of the GNU Privacy Guard (GnuPG). It is a tool to provide digital encryption and
       signing services using the OpenPGP standard. gpg2 features complete key management and all bells and  whistles
       you can expect from a decent OpenPGP implementation.


       In  contrast  to the standalone version gpg, which is more suited for server and embedded platforms, this ver‐
       sion is commonly installed under the name gpg2 and more targeted to the desktop as it requires  several  other
       modules  to  be  installed.  The standalone version will be kept maintained and it is possible to install both
       versions on the same system.  If you need to use different configuration files, you should make use  of  some‐
       thing like ‘gpg.conf-2’ instead of just ‘gpg.conf’.







RETURN VALUE
       The  program  returns  0  if everything was fine, 1 if at least a signature was bad, and other error codes for
       fatal errors.


WARNINGS
       Use a *good* password for your user account  and  a  *good*  passphrase  to  protect  your  secret  key.  This
       passphrase  is  the weakest part of the whole system. Programs to do dictionary attacks on your secret keyring
       are very easy to write and so you should protect your "~/.gnupg/" directory very well.

       Keep in mind that, if this program is used over a network  (telnet),  it  is  *very*  easy  to  spy  out  your
       passphrase!

       If  you  are  going to verify detached signatures, make sure that the program knows about it; either give both
       filenames on the command line or use '-' to specify STDIN.


INTEROPERABILITY
       GnuPG tries to be a very flexible implementation of the OpenPGP standard. In particular, GnuPG implements many
       of  the  optional  parts  of  the standard, such as the SHA-512 hash, and the ZLIB and BZIP2 compression algo‐
       rithms. It is important to be aware that not all OpenPGP programs implement these optional algorithms and that
       by  forcing  their use via the --cipher-algo, --digest-algo, --cert-digest-algo, or --compress-algo options in
       GnuPG, it is possible to create a perfectly valid OpenPGP message, but one that cannot be read by the intended
       recipient.

       There are dozens of variations of OpenPGP programs available, and each supports a slightly different subset of
       these optional algorithms.  For example, until recently, no (unhacked) version of PGP supported  the  BLOWFISH
       cipher  algorithm. A message using BLOWFISH simply could not be read by a PGP user. By default, GnuPG uses the
       standard OpenPGP preferences system that will always do the right thing and create messages that are usable by
       all  recipients,  regardless  of which OpenPGP program they use. Only override this safe default if you really
       know what you are doing.
       is listed).

       Please  remember  that option as well as command parsing stops as soon as a non-option is encountered, you can
       explicitly stop parsing by using the special option --.






   Commands not specific to the function



       --version
              Print the program version and licensing information.  Note that you cannot abbreviate this command.


       --help

       -h     Print a usage message summarizing the most useful command line options.  Note that you cannot  abbrevi‐
              ate this command.


       --warranty
              Print warranty information.


       --dump-options
              Print a list of all available options and commands.  Note that you cannot abbreviate this command.




   Commands to select the type of operation





       --sign

       -s     Make  a  signature.  This  command may be combined with --encrypt (for a signed and encrypted message),
              --symmetric (for a signed and symmetrically encrypted message), or --encrypt and  --symmetric  together
              (for  a signed message that may be decrypted via a secret key or a passphrase).  The key to be used for
              signing is chosen by default or can be set with the --local-user and --default-key options.


       --clearsign
              Make a clear text signature.  The content in a clear text signature is  readable  without  any  special
              software.  OpenPGP  software  is only needed to verify the signature.  Clear text signatures may modify
              end-of-line whitespace for platform independence and are not intended to be reversible.  The key to  be
              used for signing is chosen by default or can be set with the --local-user and --default-key options.



       --symmetric

       -c     Encrypt with a symmetric cipher using a passphrase. The default symmetric cipher used is CAST5, but may
              be chosen with the --cipher-algo option. This option may be combined with --sign (for a signed and sym‐
              metrically  encrypted  message),  --encrypt  (for a message that may be decrypted via a secret key or a
              passphrase), or --sign and --encrypt together (for a signed message that may be decrypted via a  secret
              key or a passphrase).


       --store
              Store only (make a simple RFC1991 literal data packet).


       --decrypt

       -d     Decrypt  the  file  given on the command line (or STDIN if no file is specified) and write it to STDOUT
              (or the file specified with --output). If the decrypted file is signed, the signature is also verified.
              This  command  differs from the default operation, as it never writes to the filename which is included
              in the file and it rejects files which don't begin with an encrypted message.


       --verify
              Assume that the first argument is a signed file or a detached signature and verify it without  generat‐
              ing any output. With no arguments, the signature packet is read from STDIN. If only a sigfile is given,
              it may be a complete signature or a detached signature, in which case the signed stuff is expected in a
              file without the ".sig" or ".asc" extension.  With more than 1 argument, the first should be a detached
              signature and the remaining files are the signed stuff. To read the signed stuff from STDIN, use '-' as
              the  second  filename.   For security reasons a detached signature cannot read the signed material from
              STDIN without denoting it in the above way.

              Note: When verifying a cleartext signature, gpg verifies only what makes up the cleartext  signed  data
              and  not  any extra data outside of the cleartext signature or header lines following directly the dash
              marker line.  The option --output may be used to write out the actual signed data; but there are  other
              pitfalls  with this format as well.  It is suggested to avoid cleartext signatures in favor of detached
              signatures.


       --multifile
              This modifies certain other commands to accept multiple files for processing on  the  command  line  or
              read  from  STDIN  with each filename on a separate line. This allows for many files to be processed at
              once. --multifile may currently be used along with --verify, --encrypt, and --decrypt. Note that --mul‐
              tifile --verify may not be used with detached signatures.


       --verify-files
              Identical to --multifile --verify.


       --encrypt-files
              Identical to --multifile --encrypt.


              changes. See --with-colons for a machine-parseable key listing command that is appropriate for  use  in
              scripts and other programs.


       --list-secret-keys

       -K     List  all keys from the secret keyrings, or just the ones given on the command line. A # after the let‐
              ters sec means that the secret key is not usable (for example, if it was created  via  --export-secret-
              subkeys).


       --list-sigs
              Same  as  --list-keys,  but  the  signatures are listed too.  This command has the same effect as using
              --list-keys with --with-sig-list.

              For each signature listed, there are several flags in between the "sig" tag and keyid. These flags give
              additional  information about each signature. From left to right, they are the numbers 1-3 for certifi‐
              cate check level (see --ask-cert-level), "L" for a local or non-exportable signature (see --lsign-key),
              "R"  for  a nonRevocable signature (see the --edit-key command "nrsign"), "P" for a signature that con‐
              tains a policy URL (see --cert-policy-url), "N" for a signature that contains a notation  (see  --cert-
              notation),  "X" for an eXpired signature (see --ask-cert-expire), and the numbers 1-9 or "T" for 10 and
              above to indicate trust signature levels (see the --edit-key command "tsign").


       --check-sigs
              Same as --list-sigs, but the signatures are verified.  Note that for performance reasons the revocation
              status  of  a  signing  key  is  not shown.  This command has the same effect as using --list-keys with
              --with-sig-check.

              The status of the verification is indicated by a flag directly following the "sig" tag (and thus before
              the  flags  described above for --list-sigs).  A "!" indicates that the signature has been successfully
              verified, a "-" denotes a bad signature and a "%" is used if an error occurred while checking the  sig‐
              nature (e.g. a non supported algorithm).


       --locate-keys
              Locate the keys given as arguments.  This command basically uses the same algorithm as used when locat‐
              ing keys for encryption or signing and may thus be used to see what keys gpg2 might use.  In particular
              external  methods  as  defined  by --auto-key-locate may be used to locate a key.  Only public keys are
              listed.



       --fingerprint
              List all keys (or the specified ones) along with their fingerprints. This is the same output as --list-
              keys  but  with the additional output of a line with the fingerprint. May also be combined with --list-
              sigs or --check-sigs.  If this command is given twice, the  fingerprints  of  all  secondary  keys  are
              listed too.


       --list-packets
              List only the sequence of packets. This is mainly useful for debugging.


              Present  a  menu  to allow changing the PIN of a smartcard. This functionality is also available as the
              subcommand "passwd" with the --card-edit command.


       --delete-key name
              Remove key from the public keyring. In batch mode either --yes is required or the key must be specified
              by fingerprint. This is a safeguard against accidental deletion of multiple keys.


       --delete-secret-key name
              Remove key from the secret keyring. In batch mode the key must be specified by fingerprint.


       --delete-secret-and-public-key name
              Same  as --delete-key, but if a secret key exists, it will be removed first. In batch mode the key must
              be specified by fingerprint.


       --export
              Either export all keys from all keyrings (default keyrings and those registered via option  --keyring),
              or  if  at least one name is given, those of the given name. The new keyring is written to STDOUT or to
              the file given with option --output. Use together with --armor to mail those keys.


       --send-keys key IDs
              Similar to --export but sends the keys to a keyserver.  Fingerprints may be used instead  of  key  IDs.
              Option --keyserver must be used to give the name of this keyserver. Don't send your complete keyring to
              a keyserver --- select only those keys which are new or changed by you.  If no key IDs are  given,  gpg
              does nothing.


       --export-secret-keys

       --export-secret-subkeys
              Same as --export, but exports the secret keys instead.  This is normally not very useful and a security
              risk.  The second form of the command has the special property to render the secret part of the primary
              key  useless;  this is a GNU extension to OpenPGP and other implementations can not be expected to suc‐
              cessfully import such a key.  See the option  --simple-sk-checksum  if  you  want  to  import  such  an
              exported key with an older OpenPGP implementation.


       --import

       --fast-import
              Import/merge  keys.  This adds the given keys to the keyring. The fast version is currently just a syn‐
              onym.

              There are a few other options which control how this command works.  Most notable here is the --import-
              options  merge-only  option which does not insert new keys but does only the merging of new signatures,
              user-IDs and subkeys.


       --recv-keys key IDs
              Import the keys with the given key IDs from a keyserver. Option --keyserver must be used  to  give  the
              the  search  string  for  the keyserver.  Option --keyserver must be used to give the name of this key‐
              server.  Keyservers that support different search methods allow using the syntax specified in  "How  to
              specify  a  user  ID" below. Note that different keyserver types support different search methods. Cur‐
              rently only LDAP supports them all.


       --fetch-keys URIs
              Retrieve keys located at the specified URIs. Note that different installations  of  GnuPG  may  support
              different protocols (HTTP, FTP, LDAP, etc.)


       --update-trustdb
              Do trust database maintenance. This command iterates over all keys and builds the Web of Trust. This is
              an interactive command because it may have to ask for the "ownertrust" values for keys. The user has to
              give  an  estimation  of  how far she trusts the owner of the displayed key to correctly certify (sign)
              other keys. GnuPG only asks for the ownertrust value if it has not yet been assigned to  a  key.  Using
              the --edit-key menu, the assigned value can be changed at any time.


       --check-trustdb
              Do  trust  database  maintenance without user interaction. From time to time the trust database must be
              updated so that expired keys or signatures and the resulting  changes  in  the  Web  of  Trust  can  be
              tracked. Normally, GnuPG will calculate when this is required and do it automatically unless --no-auto-
              check-trustdb is set. This command can be used to force a trust database check at any  time.  The  pro‐
              cessing is identical to that of --update-trustdb but it skips keys with a not yet defined "ownertrust".

              For use with cron jobs, this command can be used together with --batch in which case the trust database
              check is done only if a check is needed. To force a run even in batch mode add the option --yes.



       --export-ownertrust
              Send the ownertrust values to STDOUT. This is useful for backup purposes as these values are  the  only
              ones which can't be re-created from a corrupted trustdb.  Example:
                  gpg2 --export-ownertrust > otrust.txt



       --import-ownertrust
              Update  the trustdb with the ownertrust values stored in files (or STDIN if not given); existing values
              will be overwritten.  In case of a severely damaged trustdb and if you have a recent backup of the own‐
              ertrust values (e.g. in the file ‘otrust.txt’, you may re-create the trustdb using these commands:
                  cd ~/.gnupg
                  rm trustdb.gpg
                  gpg2 --import-ownertrust < otrust.txt



       --rebuild-keydb-caches
              When updating from version 1.0.6 to 1.0.7 this command should be used to create signature caches in the
              keyring. It might be handy in other situations too.


       --print-md algo

       --gen-prime mode bits
              Use the source, Luke :-). The output format is still subject to change.



       --enarmor

       --dearmor
              Pack or unpack an arbitrary input into/from an OpenPGP ASCII armor.   This  is  a  GnuPG  extension  to
              OpenPGP and in general not very useful.





   How to manage your keys


       This section explains the main commands for key management



       --gen-key
              Generate a new key pair. This command is normally only used interactively.

              There  is  an  experimental  feature  which  allows  you  to  create  keys  in batch mode. See the file
              ‘doc/DETAILS’ in the source distribution on how to use this.


       --gen-revoke name
              Generate a revocation certificate for the complete key. To revoke a subkey  or  a  signature,  use  the
              --edit command.


       --desig-revoke name
              Generate  a designated revocation certificate for a key. This allows a user (with the permission of the
              keyholder) to revoke someone else's key.



       --edit-key
              Present a menu which enables you to do most of the key management related tasks.  It expects the speci‐
              fication of a key on the command line.



              uid n  Toggle  selection of user ID or photographic user ID with index n.  Use * to select all and 0 to
                     deselect all.


              key n  Toggle selection of subkey with index n.  Use * to select all and 0 to deselect all.



              tsign  Make a trust signature. This is a signature that combines the notions of certification  (like  a
                     regular  signature),  and  trust (like the "trust" command). It is generally only useful in dis‐
                     tinct communities or groups.

              Note that "l" (for local / non-exportable), "nr" (for non-revocable, and "t" (for trust) may be  freely
              mixed and prefixed to "sign" to create a signature of any type desired.



              delsig Delete  a  signature. Note that it is not possible to retract a signature, once it has been send
                     to the public (i.e. to a keyserver).  In that case you better use revsig.


              revsig Revoke a signature. For every signature which has been generated by  one  of  the  secret  keys,
                     GnuPG asks whether a revocation certificate should be generated.


              check  Check the signatures on all selected user IDs.


              adduid Create an additional user ID.


              addphoto
                     Create  a  photographic user ID. This will prompt for a JPEG file that will be embedded into the
                     user ID. Note that a very large JPEG will make for a very large key. Also note  that  some  pro‐
                     grams will display your JPEG unchanged (GnuPG), and some programs will scale it to fit in a dia‐
                     log box (PGP).


              showphoto
                     Display the selected photographic user ID.


              deluid Delete a user ID or photographic user ID.  Note that it is not possible to retract  a  user  id,
                     once it has been send to the public (i.e. to a keyserver).  In that case you better use revuid.


              revuid Revoke a user ID or photographic user ID.


              primary
                     Flag  the  current  user  id as the primary one, removes the primary user id flag from all other
                     user ids and sets the timestamp of all affected self-signatures one second ahead. Note that set‐
                     ting  a photo user ID as primary makes it primary over other photo user IDs, and setting a regu‐
                     lar user ID as primary makes it primary over other regular user IDs.


              keyserver
                     Set a preferred keyserver for the specified user ID(s). This allows other users  to  know  where
                     you  prefer  they get your key from. See --keyserver-options honor-keyserver-url for more on how
                     this works.  Setting a value of "none" removes an existing preferred keyserver.


              showpref
                     More verbose preferences listing for the selected user ID. This shows the preferences in  effect
                     by  including  the  implied preferences of 3DES (cipher), SHA-1 (digest), and Uncompressed (com‐
                     pression) if they are not already included in the preference list. In  addition,  the  preferred
                     keyserver and signature notations (if any) are shown.


              setpref string
                     Set  the  list of user ID preferences to string for all (or just the selected) user IDs. Calling
                     setpref with no arguments sets the preference list to the default (either built-in  or  set  via
                     --default-preference-list),  and calling setpref with "none" as the argument sets an empty pref‐
                     erence list. Use gpg2 --version to get a list of available algorithms. Note that while  you  can
                     change  the preferences on an attribute user ID (aka "photo ID"), GnuPG does not select keys via
                     attribute user IDs so these preferences will not be used by GnuPG.

                     When setting preferences, you should list the algorithms in the order which you'd  like  to  see
                     them  used by someone else when encrypting a message to your key.  If you don't include 3DES, it
                     will be automatically added at the end.  Note that there are many factors that go into  choosing
                     an  algorithm  (for  example, your key may not be the only recipient), and so the remote OpenPGP
                     application being used to send to you may or may not follow your exact chosen order for a  given
                     message.   It  will, however, only choose an algorithm that is present on the preference list of
                     every recipient key.  See also the INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS section below.


              addkey Add a subkey to this key.


              addcardkey
                     Generate a subkey on a card and add it to this key.


              keytocard
                     Transfer the selected secret subkey (or the primary key if no subkey has  been  selected)  to  a
                     smartcard.  The  secret key in the keyring will be replaced by a stub if the key could be stored
                     successfully on the card and you use the save command later.  Only  certain  key  types  may  be
                     transferred  to  the  card.  A sub menu allows you to select on what card to store the key. Note
                     that it is not possible to get that key back from the card - if the card gets broken your secret
                     key will be lost unless you have a backup somewhere.


              bkuptocard file
                     Restore the given file to a card. This command may be used to restore a backup key (as generated
                     during card initialization) to a new card. In almost all cases this will be the encryption  key.
                     You  should  use this command only with the corresponding public key and make sure that the file
                     given as argument is indeed the backup to restore. You  should  then  select  2  to  restore  as
                     encryption  key.  You will first be asked to enter the passphrase of the backup key and then for
                     the Admin PIN of the card.


              delkey Remove a subkey (secondart key). Note that it is not possible to retract a subkey, once  it  has
                     been send to the public (i.e. to a keyserver).  In that case you better use revkey.


              revkey Revoke a subkey.
              enable Disable or enable an entire key. A disabled key can not normally be used for encryption.


              addrevoker
                     Add  a designated revoker to the key. This takes one optional argument: "sensitive". If a desig‐
                     nated revoker is marked as sensitive, it will not be exported by default (see export-options).


              passwd Change the passphrase of the secret key.


              toggle Toggle between public and secret key listing.


              clean  Compact (by removing all signatures except the selfsig) any user ID that  is  no  longer  usable
                     (e.g.  revoked, or expired). Then, remove any signatures that are not usable by the trust calcu‐
                     lations.  Specifically, this removes any signature that does not validate, any signature that is
                     superseded  by a later signature, revoked signatures, and signatures issued by keys that are not
                     present on the keyring.


              minimize
                     Make the key as small as possible. This removes all signatures from each user ID except for  the
                     most recent self-signature.


              cross-certify
                     Add  cross-certification  signatures to signing subkeys that may not currently have them. Cross-
                     certification signatures protect against a subtle attack against signing subkeys. See --require-
                     cross-certification.   All  new keys generated have this signature by default, so this option is
                     only useful to bring older keys up to date.


              save   Save all changes to the key rings and quit.


              quit   Quit the program without updating the key rings.

              The listing shows you the key with its secondary keys and all user ids.  The primary user id  is  indi‐
              cated  by  a  dot, and selected keys or user ids are indicated by an asterisk.  The trust value is dis‐
              played with the primary key: the first is the assigned owner trust and the  second  is  the  calculated
              trust value. Letters are used for the values:



              -      No ownertrust assigned / not yet calculated.


              e      Trust calculation has failed; probably due to an expired key.


              q      Not enough information for calculation.



       --sign-key name
              Signs  a  public  key  with  your  secret key. This is a shortcut version of the subcommand "sign" from
              --edit.


       --lsign-key name
              Signs a public key with your secret key but marks it as non-exportable. This is a shortcut  version  of
              the subcommand "lsign" from --edit-key.


       --passwd user_id
              Change  the  passphrase of the secret key belonging to the certificate specified as user_id.  This is a
              shortcut for the sub-command passwd of the edit key menu.





OPTIONS
       gpg2 features a bunch of options to control the exact behaviour and to change the default configuration.


       Long options can be put in an options file (default "~/.gnupg/gpg.conf"). Short option names will not  work  -
       for  example, "armor" is a valid option for the options file, while "a" is not. Do not write the 2 dashes, but
       simply the name of the option and any required arguments. Lines with a hash ('#') as the first non-white-space
       character  are  ignored. Commands may be put in this file too, but that is not generally useful as the command
       will execute automatically with every execution of gpg.

       Please remember that option parsing stops as soon as a non-option is  encountered,  you  can  explicitly  stop
       parsing by using the special option --.



   How to change the configuration


       These options are used to change the configuration and are usually found in the option file.



       --default-key name
              Use  name as the default key to sign with. If this option is not used, the default key is the first key
              found in the secret keyring.  Note that -u or --local-user overrides this option.


       --default-recipient name
              Use name as default recipient if option --recipient is not used and don't ask if this is a  valid  one.
              name must be non-empty.


       --default-recipient-self
              Use  the  default key as default recipient if option --recipient is not used and don't ask if this is a
              valid one. The default key is the first one from the secret keyring or the one set with --default-key.


       -q, --quiet
              Try to be as quiet as possible.


       --batch

       --no-batch
              Use batch mode.  Never ask, do not allow interactive commands.  --no-batch disables this option.   Note
              that  even  with a filename given on the command line, gpg might still need to read from STDIN (in par‐
              ticular if gpg figures that the input is a detached signature and no data  file  has  been  specified).
              Thus if you do not want to feed data via STDIN, you should connect STDIN to ‘/dev/null’.


       --no-tty
              Make  sure  that  the TTY (terminal) is never used for any output.  This option is needed in some cases
              because GnuPG sometimes prints warnings to the TTY even if --batch is used.


       --yes  Assume "yes" on most questions.


       --no   Assume "no" on most questions.



       --list-options parameters
              This is a space or comma delimited string that gives options used  when  listing  keys  and  signatures
              (that  is,  --list-keys,  --list-sigs, --list-public-keys, --list-secret-keys, and the --edit-key func‐
              tions).  Options can be prepended with a no- (after the two dashes) to give the opposite meaning.   The
              options are:



              show-photos
                     Causes --list-keys, --list-sigs, --list-public-keys, and --list-secret-keys to display any photo
                     IDs attached to the key.  Defaults to no. See also --photo-viewer.  Does not work  with  --with-
                     colons: see --attribute-fd for the appropriate way to get photo data for scripts and other fron‐
                     tends.


              show-policy-urls
                     Show policy URLs in the --list-sigs or --check-sigs listings.  Defaults to no.


              show-notations

              show-std-notations

              show-user-notations
                     Show all, IETF standard, or user-defined signature notations in the --list-sigs or  --check-sigs
                     listings. Defaults to no.


              show-unusable-subkeys
                     Show revoked and expired subkeys in key listings. Defaults to no.


              show-keyring
                     Display  the  keyring name at the head of key listings to show which keyring a given key resides
                     on. Defaults to no.


              show-sig-expire
                     Show signature expiration dates (if any) during --list-sigs or --check-sigs  listings.  Defaults
                     to no.


              show-sig-subpackets
                     Include  signature subpackets in the key listing. This option can take an optional argument list
                     of the subpackets to list. If no argument is passed, list all subpackets. Defaults to  no.  This
                     option is only meaningful when using --with-colons along with --list-sigs or --check-sigs.



       --verify-options parameters
              This  is  a  space or comma delimited string that gives options used when verifying signatures. Options
              can be prepended with a `no-' to give the opposite meaning. The options are:



              show-photos
                     Display any photo IDs present on the key that issued the signature.  Defaults to  no.  See  also
                     --photo-viewer.


              show-policy-urls
                     Show policy URLs in the signature being verified. Defaults to no.


              show-notations

              show-std-notations

              show-user-notations
                     Show  all,  IETF  standard, or user-defined signature notations in the signature being verified.
                     Defaults to IETF standard.


              show-keyserver-urls
                     Show any preferred keyserver URL in the signature being verified.  Defaults to no.


              show-uid-validity
                     Display the calculated validity of the user IDs on the key that issued the  signature.  Defaults
                     to no.

                     this option may disclose information on when and what signatures are verified or to whom data is
                     encrypted. This is similar to the "web bug" described for the auto-key-retrieve feature.


              pka-trust-increase
                     Raise the trust in a signature to full if the signature passes PKA validation.  This  option  is
                     only meaningful if pka-lookups is set.


       --enable-dsa2

       --disable-dsa2
              Enable hash truncation for all DSA keys even for old DSA Keys up to 1024 bit.  This is also the default
              with --openpgp.  Note that older versions of GnuPG also required this flag to allow the  generation  of
              DSA larger than 1024 bit.


       --photo-viewer string
              This  is  the  command  line that should be run to view a photo ID. "%i" will be expanded to a filename
              containing the photo. "%I" does the same, except the file will not be deleted once  the  viewer  exits.
              Other  flags  are "%k" for the key ID, "%K" for the long key ID, "%f" for the key fingerprint, "%t" for
              the extension of the image type (e.g. "jpg"), "%T" for the MIME type of the image (e.g.  "image/jpeg"),
              "%v"  for  the  single-character calculated validity of the image being viewed (e.g. "f"), "%V" for the
              calculated validity as a string (e.g.  "full"), and "%%" for an actual percent sign. If neither  %i  or
              %I are present, then the photo will be supplied to the viewer on standard input.

              The  default  viewer  is  "xloadimage  -fork -quiet -title 'KeyID 0x%k' STDIN". Note that if your image
              viewer program is not secure, then executing it from GnuPG does not make it secure.


       --exec-path string
              Sets a list of directories to search for photo viewers and keyserver helpers.  If  not  provided,  key‐
              server helpers use the compiled-in default directory, and photo viewers use the $PATH environment vari‐
              able.  Note, that on W32 system this value is ignored when searching for keyserver helpers.


       --keyring file
              Add file to the current list of keyrings. If file begins with a tilde and a slash, these  are  replaced
              by the $HOME directory. If the filename does not contain a slash, it is assumed to be in the GnuPG home
              directory ("~/.gnupg" if --homedir or $GNUPGHOME is not used).

              Note that this adds a keyring to the current list. If the intent is to use the specified keyring alone,
              use --keyring along with --no-default-keyring.


       --secret-keyring file
              Same as --keyring but for the secret keyrings.


       --primary-keyring file
              Designate file as the primary public keyring. This means that newly imported keys (via --import or key‐
              server --recv-from) will go to this keyring.








       --display-charset name
              Set  the name of the native character set. This is used to convert some informational strings like user
              IDs to the proper UTF-8 encoding.  Note that this has nothing to do with the character set of  data  to
              be  encrypted  or  signed;  GnuPG  does  not recode user-supplied data. If this option is not used, the
              default character set is determined from the current locale. A verbosity level of 3  shows  the  chosen
              set.  Valid values for name are:



              iso-8859-1
                     This is the Latin 1 set.


              iso-8859-2
                     The Latin 2 set.


              iso-8859-15
                     This is currently an alias for the Latin 1 set.


              koi8-r The usual Russian set (rfc1489).


              utf-8  Bypass all translations and assume that the OS uses native UTF-8 encoding.


       --utf8-strings

       --no-utf8-strings
              Assume  that  command  line  arguments are given as UTF8 strings. The default (--no-utf8-strings) is to
              assume that arguments are encoded in the character set as specified by --display-charset. These options
              affect all following arguments. Both options may be used multiple times.



       --options file
              Read  options  from  file and do not try to read them from the default options file in the homedir (see
              --homedir). This option is ignored if used in an options file.


       --no-options
              Shortcut for --options /dev/null. This option is detected before an attempt to  open  an  option  file.
              Using this option will also prevent the creation of a ‘~/.gnupg’ homedir.


       -z n


              than half the memory, but also runs at half the speed. This is useful under extreme low memory  circum‐
              stances when the file was originally compressed at a high --bzip2-compress-level.



       --mangle-dos-filenames

       --no-mangle-dos-filenames
              Older  version of Windows cannot handle filenames with more than one dot. --mangle-dos-filenames causes
              GnuPG to replace (rather than add to) the extension of an output filename to avoid this  problem.  This
              option is off by default and has no effect on non-Windows platforms.


       --ask-cert-level

       --no-ask-cert-level
              When  making  a  key  signature, prompt for a certification level. If this option is not specified, the
              certification level used is set via --default-cert-level. See --default-cert-level for  information  on
              the  specific  levels  and  how  they  are  used. --no-ask-cert-level disables this option. This option
              defaults to no.


       --default-cert-level n
              The default to use for the check level when signing a key.

              0 means you make no particular claim as to how carefully you verified the key.

              1 means you believe the key is owned by the person who claims to own it but you could not, or  did  not
              verify  the  key  at  all.  This  is  useful  for a "persona" verification, where you sign the key of a
              pseudonymous user.

              2 means you did casual verification of the key. For example, this could mean that you verified the  key
              fingerprint and checked the user ID on the key against a photo ID.

              3  means  you did extensive verification of the key. For example, this could mean that you verified the
              key fingerprint with the owner of the key in person, and that you checked, by means of a hard to  forge
              document  with  a  photo ID (such as a passport) that the name of the key owner matches the name in the
              user ID on the key, and finally that you verified (by exchange of email) that the email address on  the
              key belongs to the key owner.

              Note  that the examples given above for levels 2 and 3 are just that: examples. In the end, it is up to
              you to decide just what "casual" and "extensive" mean to you.

              This option defaults to 0 (no particular claim).


       --min-cert-level
              When building the trust database, treat any  signatures  with  a  certification  level  below  this  as
              invalid.  Defaults  to  2, which disregards level 1 signatures. Note that level 0 "no particular claim"
              signatures are always accepted.


       --trusted-key long key ID
              Assume that the specified key (which must be given as a full 8 byte key ID) is as trustworthy as one of

              classic
                     This is the standard Web of Trust as used in PGP 2.x and earlier.


              direct Key validity is set directly by the user and not calculated via the Web of Trust.


              always Skip  key validation and assume that used keys are always fully trusted. You generally won't use
                     this unless you are using some external validation  scheme.  This  option  also  suppresses  the
                     "[uncertain]"  tag  printed  with signature checks when there is no evidence that the user ID is
                     bound to the key.


              auto   Select the trust model depending on whatever the internal  trust  database  says.  This  is  the
                     default model if such a database already exists.


       --auto-key-locate parameters

       --no-auto-key-locate
              GnuPG  can  automatically  locate  and  retrieve  keys  as  needed using this option. This happens when
              encrypting to an email address (in the "[email protected]" form), and there are no [email protected] keys
              on  the local keyring.  This option takes any number of the following mechanisms, in the order they are
              to be tried:



              cert   Locate a key using DNS CERT, as specified in rfc4398.


              pka    Locate a key using DNS PKA.


              ldap   Using DNS Service Discovery, check the domain in question for any LDAP keyservers  to  use.   If
                     this   fails,   attempt   to  locate  the  key  using  the  PGP  Universal  method  of  checking
                     'ldap://keys.(thedomain)'.


              keyserver
                     Locate a key using whatever keyserver is defined using the --keyserver option.


              keyserver-URL
                     In addition, a keyserver URL as used in the --keyserver option may be used here  to  query  that
                     particular keyserver.


              local  Locate  the key using the local keyrings.  This mechanism allows to select the order a local key
                     lookup is done.  Thus using '--auto-key-locate local' is identical to --no-auto-key-locate.


              nodefault
                     This flag disables the standard local key lookup, done before any of the mechanisms  defined  by

       --keyserver name
              Use  name  as  your keyserver. This is the server that --recv-keys, --send-keys, and --search-keys will
              communicate with to receive keys from, send keys to, and search for keys on. The format of the name  is
              a  URI:  `scheme:[//]keyservername[:port]'  The scheme is the type of keyserver: "hkp" for the HTTP (or
              compatible) keyservers, "ldap" for the LDAP keyservers, or "mailto" for the Graff email keyserver. Note
              that  your particular installation of GnuPG may have other keyserver types available as well. Keyserver
              schemes are case-insensitive. After the keyserver name, optional keyserver configuration options may be
              provided.  These are the same as the global --keyserver-options from below, but apply only to this par‐
              ticular keyserver.

              Most keyservers synchronize with each other, so there is generally no need to send keys  to  more  than
              one  server. The keyserver hkp://keys.gnupg.net uses round robin DNS to give a different keyserver each
              time you use it.


       --keyserver-options name=value1
              This is a space or comma delimited string that gives options for the keyserver. Options can be prefixed
              with  a  `no-' to give the opposite meaning. Valid import-options or export-options may be used here as
              well to apply to importing (--recv-key) or exporting (--send-key) a key from a keyserver. While not all
              options are available for all keyserver types, some common options are:



              include-revoked
                     When  searching  for  a key with --search-keys, include keys that are marked on the keyserver as
                     revoked. Note that not all keyservers differentiate between revoked and unrevoked keys, and  for
                     such  keyservers  this option is meaningless. Note also that most keyservers do not have crypto‐
                     graphic verification of key revocations, and so turning this option off may result  in  skipping
                     keys that are incorrectly marked as revoked.


              include-disabled
                     When  searching  for  a key with --search-keys, include keys that are marked on the keyserver as
                     disabled. Note that this option is not used with HKP keyservers.


              auto-key-retrieve
                     This option enables the automatic retrieving of keys from a keyserver when verifying  signatures
                     made by keys that are not on the local keyring.

                     Note  that  this  option  makes a "web bug" like behavior possible.  Keyserver operators can see
                     which keys you request, so by sending you a message signed by a brand new key (which  you  natu‐
                     rally  will  not have on your local keyring), the operator can tell both your IP address and the
                     time when you verified the signature.


              honor-keyserver-url
                     When using --refresh-keys, if the key in question has a preferred keyserver URL, then  use  that
                     preferred  keyserver  to refresh the key from. In addition, if auto-key-retrieve is set, and the
                     signature being verified has a preferred keyserver URL, then use  that  preferred  keyserver  to
                     fetch the key from. Defaults to yes.


              honor-pka-record

                     cate. On some platforms (such as Win32 and RISC OS), this option is always enabled.


              keep-temp-files
                     If  using `use-temp-files', do not delete the temp files after using them. This option is useful
                     to learn the keyserver communication protocol by reading the temporary files.


              verbose
                     Tell the keyserver helper program to be more verbose. This option can be repeated multiple times
                     to increase the verbosity level.


              timeout
                     Tell  the  keyserver  helper program how long (in seconds) to try and perform a keyserver action
                     before giving up. Note that performing multiple actions at the same time uses this timeout value
                     per  action.   For  example,  when retrieving multiple keys via --recv-keys, the timeout applies
                     separately to each key retrieval, and not to the --recv-keys command as a whole. Defaults to  30
                     seconds.


              http-proxy=value
                     Set  the  proxy to use for HTTP and HKP keyservers.  This overrides the "http_proxy" environment
                     variable, if any.



              max-cert-size
                     When retrieving a key via DNS CERT, only accept keys up to this size.  Defaults to 16384 bytes.


              debug  Turn on debug output in the keyserver helper program.  Note that the  details  of  debug  output
                     depends  on which keyserver helper program is being used, and in turn, on any libraries that the
                     keyserver helper program uses internally (libcurl, openldap, etc).


              check-cert
                     Enable certificate checking if the keyserver presents one (for hkps or ldaps).  Defaults to on.


              ca-cert-file
                     Provide a certificate store to override the system default.  Only  necessary  if  check-cert  is
                     enabled,  and  the keyserver is using a certificate that is not present in a system default cer‐
                     tificate list.

                     Note that depending on the SSL library that the keyserver helper is built with, this  may  actu‐
                     ally be a directory or a file.


       --completes-needed n
              Number of completely trusted users to introduce a new key signer (defaults to 1).


       --marginals-needed n

              the  secret  key is encrypted - the simplest way to make this happen is to change the passphrase on the
              key (even changing it to the same value is acceptable).


       --no-sig-cache
              Do not cache the verification status of key signatures.  Caching gives a much better performance in key
              listings. However, if you suspect that your public keyring is not save against write modifications, you
              can use this option to disable the caching. It probably does not make sense to disable it  because  all
              kind of damage can be done if someone else has write access to your public keyring.


       --no-sig-create-check
              GnuPG  normally  verifies each signature right after creation to protect against bugs and hardware mal‐
              functions which could leak out bits from the secret key. This extra verification needs some time (about
              115%  for  DSA  keys), and so this option can be used to disable it.  However, due to the fact that the
              signature creation needs manual interaction, this performance penalty does not matter in most settings.


       --auto-check-trustdb

       --no-auto-check-trustdb
              If GnuPG feels that its information about the Web of Trust has to be updated, it automatically runs the
              --check-trustdb command internally.  This may be a time consuming process. --no-auto-check-trustdb dis‐
              ables this option.


       --use-agent

       --no-use-agent
              This is dummy option. gpg2 always requires the agent.


       --gpg-agent-info
              This is dummy option. It has no effect when used with gpg2.


       --lock-once
              Lock the databases the first time a lock is requested and do not release the  lock  until  the  process
              terminates.


       --lock-multiple
              Release  the  locks  every time a lock is no longer needed. Use this to override a previous --lock-once
              from a config file.


       --lock-never
              Disable locking entirely. This option should be used only in very special environments, where it can be
              assured that only one process is accessing those files. A bootable floppy with a stand-alone encryption
              system will probably use this. Improper usage of this option may lead to data and key corruption.


       --exit-on-status-write-error
              This option will cause write errors on the status FD to immediately terminate the process. That  should

       --no-random-seed-file
              GnuPG  uses  a  file  to store its internal random pool over invocations.  This makes random generation
              faster; however sometimes write operations are not desired. This option can be  used  to  achieve  that
              with the cost of slower random generation.


       --no-greeting
              Suppress the initial copyright message.


       --no-secmem-warning
              Suppress the warning about "using insecure memory".


       --no-permission-warning
              Suppress  the  warning about unsafe file and home directory (--homedir) permissions. Note that the per‐
              mission checks that GnuPG performs are not intended to be authoritative, but rather  they  simply  warn
              about certain common permission problems. Do not assume that the lack of a warning means that your sys‐
              tem is secure.

              Note that the warning for unsafe --homedir permissions cannot be suppressed in the  gpg.conf  file,  as
              this  would  allow an attacker to place an unsafe gpg.conf file in place, and use this file to suppress
              warnings about itself. The --homedir permissions warning may only be suppressed on the command line.


       --no-mdc-warning
              Suppress the warning about missing MDC integrity protection.


       --require-secmem

       --no-require-secmem
              Refuse to run if GnuPG cannot get secure memory. Defaults to no (i.e. run, but give a warning).



       --require-cross-certification

       --no-require-cross-certification
              When verifying a signature made from a subkey, ensure that the cross certification "back signature"  on
              the  subkey is present and valid.  This protects against a subtle attack against subkeys that can sign.
              Defaults to --require-cross-certification for gpg2.


       --expert

       --no-expert
              Allow the user to do certain nonsensical or "silly" things like signing an expired or revoked  key,  or
              certain  potentially  incompatible things like generating unusual key types. This also disables certain
              warning messages about potentially incompatible actions. As  the  name  implies,  this  option  is  for
              experts  only.  If  you don't fully understand the implications of what it allows you to do, leave this
              off. --no-expert disables this option.

              user-id unless --default-recipient is given.


       --hidden-recipient name

       -R     Encrypt  for  user  ID  name,  but  hide  the  key ID of this user's key. This option helps to hide the
              receiver of the message and is a limited countermeasure against traffic analysis.  If  this  option  or
              --recipient is not specified, GnuPG asks for the user ID unless --default-recipient is given.


       --encrypt-to name
              Same  as --recipient but this one is intended for use in the options file and may be used with your own
              user-id as an "encrypt-to-self". These keys are only used when there are other recipients given  either
              by  use  of --recipient or by the asked user id.  No trust checking is performed for these user ids and
              even disabled keys can be used.


       --hidden-encrypt-to name
              Same as --hidden-recipient but this one is intended for use in the options file and may  be  used  with
              your  own  user-id as a hidden "encrypt-to-self". These keys are only used when there are other recipi‐
              ents given either by use of --recipient or by the asked user id.  No trust checking  is  performed  for
              these user ids and even disabled keys can be used.


       --no-encrypt-to
              Disable the use of all --encrypt-to and --hidden-encrypt-to keys.


       --group name=value1
              Sets  up  a  named  group, which is similar to aliases in email programs.  Any time the group name is a
              recipient (-r or --recipient), it will be expanded to the values specified. Multiple  groups  with  the
              same name are automatically merged into a single group.

              The  values  are  key  IDs or fingerprints, but any key description is accepted. Note that a value with
              spaces in it will be treated as two different values. Note also there is only one  level  of  expansion
              ---  you  cannot make an group that points to another group. When used from the command line, it may be
              necessary to quote the argument to this option to prevent the shell from treating it as multiple  argu‐
              ments.


       --ungroup name
              Remove a given entry from the --group list.


       --no-groups
              Remove all entries from the --group list.


       --local-user name

       -u     Use name as the key to sign with. Note that this option overrides --default-key.


       --try-secret-key name

              a bogus key ID.


       --skip-hidden-recipients

       --no-skip-hidden-recipients
              During  decryption  skip  all  anonymous recipients.  This option helps in the case that people use the
              hidden recipients feature to hide there own encrypt-to key from others.  If  oneself  has  many  secret
              keys  this  may lead to a major annoyance because all keys are tried in turn to decrypt soemthing which
              was not really intended for it.  The drawback of this option is that it is currently  not  possible  to
              decrypt a message which includes real anonymous recipients.





   Input and Output




       --armor

       -a     Create ASCII armored output.  The default is to create the binary OpenPGP format.


       --no-armor
              Assume the input data is not in ASCII armored format.


       --output file

       -o file
              Write output to file.


       --max-output n
              This  option  sets  a limit on the number of bytes that will be generated when processing a file. Since
              OpenPGP supports various levels of compression, it is possible that the plaintext of  a  given  message
              may  be  significantly  larger  than the original OpenPGP message. While GnuPG works properly with such
              messages, there is often a desire to set a maximum file size that will be generated  before  processing
              is forced to stop by the OS limits. Defaults to 0, which means "no limit".


       --import-options parameters
              This  is  a  space  or  comma  delimited  string  that gives options for importing keys. Options can be
              prepended with a `no-' to give the opposite meaning. The options are:



              import-local-sigs
                     Allow importing key signatures marked as "local". This is not generally useful unless  a  shared
                     keyring scheme is being used.  Defaults to no.


              import-clean
                     After  import,  compact  (remove all signatures except the self-signature) any user IDs from the
                     new key that are not usable.  Then, remove any signatures from the new key that are not  usable.
                     This  includes  signatures  that  were  issued by keys that are not present on the keyring. This
                     option is the same as running the --edit-key command "clean" after import. Defaults to no.


              import-minimal
                     Import the smallest key possible. This removes all signatures except the most recent self-signa‐
                     ture on each user ID. This option is the same as running the --edit-key command "minimize" after
                     import.  Defaults to no.


       --export-options parameters
              This is a space or comma delimited string that  gives  options  for  exporting  keys.  Options  can  be
              prepended with a `no-' to give the opposite meaning. The options are:



              export-local-sigs
                     Allow  exporting  key signatures marked as "local". This is not generally useful unless a shared
                     keyring scheme is being used.  Defaults to no.


              export-attributes
                     Include attribute user IDs (photo IDs) while exporting. This is useful to export  keys  if  they
                     are  going to be used by an OpenPGP program that does not accept attribute user IDs. Defaults to
                     yes.


              export-sensitive-revkeys
                     Include designated revoker information that was marked as "sensitive". Defaults to no.


              export-reset-subkey-passwd
                     When using the --export-secret-subkeys command, this  option  resets  the  passphrases  for  all
                     exported  subkeys  to  empty.  This is useful when the exported subkey is to be used on an unat‐
                     tended machine where a passphrase doesn't necessarily make sense. Defaults to no.


              export-clean
                     Compact (remove all signatures from) user IDs on the key being exported if the user IDs are  not
                     usable.  Also,  do  not export any signatures that are not usable. This includes signatures that
                     were issued by keys that are not present on the keyring. This option is the same as running  the
                     --edit-key  command "clean" before export except that the local copy of the key is not modified.
                     Defaults to no.


              export-minimal
                     Export the smallest key possible. This removes all signatures except the most recent self-signa‐
                     ture  on  each  user  ID.  This  option is the same as running the --edit-key command "minimize"
                     before export except that the local copy of the key is not modified. Defaults to no.



       --with-fingerprint
              Same  as  the  command --fingerprint but changes only the format of the output and may be used together
              with another command.


       --with-keygrip
              Include the keygrip in the key listings.




   OpenPGP protocol specific options.




       -t, --textmode

       --no-textmode
              Treat input files as text and store them in the OpenPGP canonical text form with standard  "CRLF"  line
              endings.  This  also sets the necessary flags to inform the recipient that the encrypted or signed data
              is text and may need its line endings converted back to whatever the local system uses. This option  is
              useful  when communicating between two platforms that have different line ending conventions (UNIX-like
              to Mac, Mac to Windows, etc). --no-textmode disables this option, and is the default.



       --force-v3-sigs

       --no-force-v3-sigs
              OpenPGP states that an implementation should generate v4 signatures but PGP versions 5 through  7  only
              recognize v4 signatures on key material. This option forces v3 signatures for signatures on data.  Note
              that this option implies --no-ask-sig-expire, and unsets --sig-policy-url, --sig-notation,  and  --sig-
              keyserver-url,  as  these features cannot be used with v3 signatures.  --no-force-v3-sigs disables this
              option.  Defaults to no.


       --force-v4-certs

       --no-force-v4-certs
              Always use v4 key signatures even on v3 keys. This option also changes the default hash  algorithm  for
              v3 RSA keys from MD5 to SHA-1.  --no-force-v4-certs disables this option.


       --force-mdc
              Force  the  use  of  encryption  with a modification detection code. This is always used with the newer
              ciphers (those with a blocksize greater than 64 bits), or if all of the  recipient  keys  indicate  MDC
              support in their feature flags.


       --disable-mdc
              Disable  the use of the modification detection code. Note that by using this option, the encrypted mes‐
              Set the list of personal digest preferences to string.  Use gpg2 --version to get a list  of  available
              algorithms,  and  use  none  to  set no preference at all.  This allows the user to safely override the
              algorithm chosen by the recipient key preferences, as GPG will only select an algorithm that is  usable
              by  all  recipients.   The  most  highly ranked digest algorithm in this list is also used when signing
              without encryption (e.g. --clearsign or --sign).


       --personal-compress-preferences string
              Set the list of personal compression preferences to string.  Use gpg2 --version to get a list of avail‐
              able algorithms, and use none to set no preference at all.  This allows the user to safely override the
              algorithm chosen by the recipient key preferences, as GPG will only select an algorithm that is  usable
              by  all  recipients.  The most highly ranked compression algorithm in this list is also used when there
              are no recipient keys to consider (e.g. --symmetric).


       --s2k-cipher-algo name
              Use name as the cipher algorithm used to protect secret keys.  The default cipher is CAST5. This cipher
              is  also  used  for  conventional  encryption if --personal-cipher-preferences and --cipher-algo is not
              given.


       --s2k-digest-algo name
              Use name as the digest algorithm used to mangle the passphrases.  The default algorithm is SHA-1.


       --s2k-mode n
              Selects how passphrases are mangled. If n is 0 a plain passphrase (which is not  recommended)  will  be
              used,  a  1  adds a salt to the passphrase and a 3 (the default) iterates the whole process a number of
              times (see --s2k-count).  Unless --rfc1991 is used, this mode is also used for conventional encryption.


       --s2k-count n
              Specify how many times the passphrase mangling is repeated.  This value  may  range  between  1024  and
              65011712  inclusive.   The  default  is  inquired  from  gpg-agent.   Note  that  not all values in the
              1024-65011712 range are legal and if an illegal value is selected, GnuPG will round up to  the  nearest
              legal value.  This option is only meaningful if --s2k-mode is 3.





   Compliance options


       These options control what GnuPG is compliant to. Only one of these options may be active at a time. Note that
       the default setting of this is nearly always the correct one. See the INTEROPERABILITY WITH OTHER OPENPGP PRO‐
       GRAMS section below before using one of these options.



       --gnupg
              Use  standard GnuPG behavior. This is essentially OpenPGP behavior (see --openpgp), but with some addi‐
              tional workarounds for common compatibility problems in different versions of PGP. This is the  default
              option,  so  it is not generally needed, but it may be useful to override a different compliance option


       --rfc2440
              Reset all packet, cipher and digest options to strict RFC-2440 behavior.


       --rfc1991
              Try to be more RFC-1991 (PGP 2.x) compliant.


       --pgp2 Set  up  all  options  to  be  as  PGP  2.x compliant as possible, and warn if an action is taken (e.g.
              encrypting to a non-RSA key) that will create a message that PGP 2.x will not be able to  handle.  Note
              that  `PGP  2.x' here means `MIT PGP 2.6.2'. There are other versions of PGP 2.x available, but the MIT
              release is a good common baseline.

              This option implies --rfc1991  --disable-mdc  --no-force-v4-certs  --escape-from-lines  --force-v3-sigs
              --cipher-algo IDEA --digest-algo MD5 --compress-algo ZIP. It also disables --textmode when encrypting.


       --pgp6 Set up all options to be as PGP 6 compliant as possible. This restricts you to the ciphers IDEA (if the
              IDEA plugin is installed), 3DES, and CAST5, the hashes MD5, SHA1 and  RIPEMD160,  and  the  compression
              algorithms  none and ZIP. This also disables --throw-keyids, and making signatures with signing subkeys
              as PGP 6 does not understand signatures made by signing subkeys.

              This option implies --disable-mdc --escape-from-lines --force-v3-sigs.


       --pgp7 Set up all options to be as PGP 7 compliant as possible. This is identical to --pgp6 except  that  MDCs
              are  not  disabled,  and  the  list of allowable ciphers is expanded to add AES128, AES192, AES256, and
              TWOFISH.


       --pgp8 Set up all options to be as PGP 8 compliant as possible. PGP 8 is a lot closer to the OpenPGP  standard
              than  previous versions of PGP, so all this does is disable --throw-keyids and set --escape-from-lines.
              All algorithms are allowed except for the SHA224, SHA384, and SHA512 digests.





   Doing things one usually doesn't want to do.




       -n

       --dry-run
              Don't make any changes (this is not completely implemented).


       --list-only
              Changes the behaviour of some commands. This is like --dry-run but different in some cases. The  seman‐
              tic  of  this command may be extended in the future. Currently it only skips the actual decryption pass

              none   No debugging at all.  A value of less than 1 may be used instead of the keyword.

              basic  Some basic debug messages.  A value between 1 and 2 may be used instead of the keyword.

              advanced
                     More verbose debug messages.  A value between 3 and 5 may be used instead of the keyword.

              expert Even more detailed messages.  A value between 6 and 8 may be used instead of the keyword.

              guru   All of the debug messages you can get. A value greater than 8 may be used instead  of  the  key‐
                     word.  The creation of hash tracing files is only enabled if the keyword is used.

       How  these  messages  are  mapped  to  the  actual  debugging flags is not specified and may change with newer
       releases of this program. They are however carefully selected to best aid in debugging.


       --debug flags
              Set debugging flags. All flags are or-ed and flags may be given in C syntax (e.g. 0x0042).


       --debug-all
              Set all useful debugging flags.



       --faked-system-time epoch
              This option is only useful for testing; it sets the system time back or forth to  epoch  which  is  the
              number  of  seconds  elapsed  since the year 1970.  Alternatively epoch may be given as a full ISO time
              string (e.g. "20070924T154812").


       --enable-progress-filter
              Enable certain PROGRESS status outputs. This option allows frontends to display  a  progress  indicator
              while gpg is processing larger files.  There is a slight performance overhead using it.


       --status-fd n
              Write special status strings to the file descriptor n.  See the file DETAILS in the documentation for a
              listing of them.


       --status-file file
              Same as --status-fd, except the status data is written to file file.


       --logger-fd n
              Write log output to file descriptor n and not to STDERR.


       --log-file file

       --logger-file file
              Same as --logger-fd, except the logger data is written to file file.   Note  that  --log-file  is  only

       --comment string

       --no-comments
              Use  string  as  a  comment  string  in  clear  text signatures and ASCII armored messages or keys (see
              --armor). The default behavior is not to use a comment string. --comment may be repeated multiple times
              to  get  multiple  comment  strings. --no-comments removes all comments.  It is a good idea to keep the
              length of a single comment below 60 characters to avoid  problems  with  mail  programs  wrapping  such
              lines.  Note that comment lines, like all other header lines, are not protected by the signature.


       --emit-version

       --no-emit-version
              Force inclusion of the version string in ASCII armored output.  --no-emit-version disables this option.


       --sig-notation name=value

       --cert-notation name=value

       -N, --set-notation name=value
              Put the name value pair into the signature as notation data.  name must consist only of printable char‐
              acters or spaces, and must contain a '@' character in the form [email protected] (substituting
              the  appropriate  keyname  and  domain name, of course).  This is to help prevent pollution of the IETF
              reserved notation namespace. The --expert flag overrides the '@' check.  value  may  be  any  printable
              string;  it  will be encoded in UTF8, so you should check that your --display-charset is set correctly.
              If you prefix name with an exclamation mark  (!),  the  notation  data  will  be  flagged  as  critical
              (rfc4880:5.2.3.16). --sig-notation sets a notation for data signatures. --cert-notation sets a notation
              for key signatures (certifications). --set-notation sets both.

              There are special codes that may be used in notation names. "%k" will be expanded into the  key  ID  of
              the  key  being signed, "%K" into the long key ID of the key being signed, "%f" into the fingerprint of
              the key being signed, "%s" into the key ID of the key making the signature, "%S" into the long  key  ID
              of the key making the signature, "%g" into the fingerprint of the key making the signature (which might
              be a subkey), "%p" into the fingerprint of the primary key of the key making the signature,  "%c"  into
              the  signature  count  from the OpenPGP smartcard, and "%%" results in a single "%". %k, %K, and %f are
              only meaningful when making a key signature (certification), and %c is only meaningful when  using  the
              OpenPGP smartcard.


       --sig-policy-url string

       --cert-policy-url string

       --set-policy-url string
              Use  string  as  a  Policy URL for signatures (rfc4880:5.2.3.20).  If you prefix it with an exclamation
              mark (!), the policy URL packet will be flagged as critical. --sig-policy-url sets  a  policy  url  for
              data signatures. --cert-policy-url sets a policy url for key signatures (certifications). --set-policy-
              url sets both.

              The same %-expandos used for notation data are available here as well.



       --for-your-eyes-only

       --no-for-your-eyes-only
              Set the `for your eyes only' flag in the message. This causes GnuPG to refuse to save the  file  unless
              the --output option is given, and PGP to use a "secure viewer" with a claimed Tempest-resistant font to
              display the message. This  option  overrides  --set-filename.   --no-for-your-eyes-only  disables  this
              option.


       --use-embedded-filename

       --no-use-embedded-filename
              Try  to  create a file with a name as embedded in the data. This can be a dangerous option as it allows
              to overwrite files. Defaults to no.


       --cipher-algo name
              Use name as cipher algorithm. Running the program with the command --version yields a list of supported
              algorithms.  If  this is not used the cipher algorithm is selected from the preferences stored with the
              key. In general, you do not want to use this option as it allows you to violate the  OpenPGP  standard.
              --personal-cipher-preferences is the safe way to accomplish the same thing.


       --digest-algo name
              Use  name as the message digest algorithm. Running the program with the command --version yields a list
              of supported algorithms. In general, you do not want to use this option as it allows you to violate the
              OpenPGP standard. --personal-digest-preferences is the safe way to accomplish the same thing.


       --compress-algo name
              Use  compression algorithm name. "zlib" is RFC-1950 ZLIB compression. "zip" is RFC-1951 ZIP compression
              which is used by PGP.  "bzip2" is a more modern compression scheme that can compress some things better
              than  zip  or  zlib,  but at the cost of more memory used during compression and decompression. "uncom‐
              pressed" or "none" disables compression. If this option is not used, the default behavior is to examine
              the recipient key preferences to see which algorithms the recipient supports. If all else fails, ZIP is
              used for maximum compatibility.

              ZLIB may give better compression results than ZIP, as the compression window size is not limited to 8k.
              BZIP2 may give even better compression results than that, but will use a significantly larger amount of
              memory while compressing and decompressing. This may be significant in  low  memory  situations.  Note,
              however,  that  PGP (all versions) only supports ZIP compression. Using any algorithm other than ZIP or
              "none" will make the message unreadable with PGP. In general, you do not want to use this option as  it
              allows  you  to violate the OpenPGP standard. --personal-compress-preferences is the safe way to accom‐
              plish the same thing.


       --cert-digest-algo name
              Use name as the message digest algorithm used when signing a key. Running the program with the  command
              --version  yields  a  list of supported algorithms. Be aware that if you choose an algorithm that GnuPG
              supports but other OpenPGP implementations do not, then some users will not be able to use the key sig‐
              natures you make, or quite possibly your entire key.


       --disable-cipher-algo name

              Do  not put the recipient key IDs into encrypted messages. This helps to hide the receivers of the mes‐
              sage and is a limited countermeasure against traffic analysis. ([Using a little social engineering any‐
              one who is able to decrypt the message can check whether one of the other recipients is the one he sus‐
              pects.])  On the receiving side, it may slow down the decryption process because all  available  secret
              keys  must  be  tried.   --no-throw-keyids disables this option. This option is essentially the same as
              using --hidden-recipient for all recipients.


       --not-dash-escaped
              This option changes the behavior of cleartext signatures so that they can be used for patch files.  You
              should  not send such an armored file via email because all spaces and line endings are hashed too. You
              can not use this option for data which has 5 dashes at the beginning of a line, patch files don't  have
              this. A special armor header line tells GnuPG about this cleartext signature option.


       --escape-from-lines

       --no-escape-from-lines
              Because  some mailers change lines starting with "From " to ">From " it is good to handle such lines in
              a special way when creating cleartext signatures to prevent the mail system from  breaking  the  signa‐
              ture.  Note that all other PGP versions do it this way too.  Enabled by default. --no-escape-from-lines
              disables this option.


       --passphrase-repeat n
              Specify how many times gpg2 will request a new passphrase be repeated.  This is useful for helping mem‐
              orize a passphrase.  Defaults to 1 repetition.


       --passphrase-fd n
              Read the passphrase from file descriptor n. Only the first line will be read from file descriptor n. If
              you use 0 for n, the passphrase will be read from STDIN. This can only be used if only  one  passphrase
              is  supplied.   Note that this passphrase is only used if the option --batch has also been given.  This
              is different from gpg.


       --passphrase-file file
              Read the passphrase from file file. Only the first line will be read from file file. This can  only  be
              used  if  only  one passphrase is supplied. Obviously, a passphrase stored in a file is of questionable
              security if other users can read this file. Don't use this option if you can avoid it.  Note that  this
              passphrase is only used if the option --batch has also been given.  This is different from gpg.


       --passphrase string
              Use string as the passphrase. This can only be used if only one passphrase is supplied. Obviously, this
              is of very questionable security on a multi-user system. Don't use this option if  you  can  avoid  it.
              Note  that  this  passphrase is only used if the option --batch has also been given.  This is different
              from gpg.


       --pinentry-mode mode
              Set the pinentry mode to mode.  Allowed values for mode are:

              default

       --command-fd n
              This is a replacement for the deprecated shared-memory IPC mode.  If this option is enabled, user input
              on questions is not expected from the TTY but from  the  given  file  descriptor.  It  should  be  used
              together  with  --status-fd.  See the file doc/DETAILS in the source distribution for details on how to
              use it.


       --command-file file
              Same as --command-fd, except the commands are read out of file file


       --allow-non-selfsigned-uid

       --no-allow-non-selfsigned-uid
              Allow the import and use of keys with user IDs which are not self-signed. This is not recommended, as a
              non self-signed user ID is trivial to forge. --no-allow-non-selfsigned-uid disables.


       --allow-freeform-uid
              Disable  all  checks  on the form of the user ID while generating a new one. This option should only be
              used in very special environments as it does not ensure the de-facto standard format of user IDs.


       --ignore-time-conflict
              GnuPG normally checks that the timestamps associated with keys and signatures  have  plausible  values.
              However,  sometimes a signature seems to be older than the key due to clock problems. This option makes
              these checks just a warning. See also --ignore-valid-from for timestamp issues on subkeys.


       --ignore-valid-from
              GnuPG normally does not select and use subkeys created in the future.  This option allows  the  use  of
              such  keys  and  thus  exhibits the pre-1.0.7 behaviour. You should not use this option unless there is
              some clock problem. See also --ignore-time-conflict for timestamp issues with signatures.


       --ignore-crc-error
              The ASCII armor used by OpenPGP is protected by a CRC checksum against transmission  errors.  Occasion‐
              ally  the  CRC gets mangled somewhere on the transmission channel but the actual content (which is pro‐
              tected by the OpenPGP protocol anyway) is still okay. This option allows GnuPG to ignore CRC errors.


       --ignore-mdc-error
              This option changes a MDC integrity protection failure into a warning.  This can be useful if a message
              is  partially  corrupt, but it is necessary to get as much data as possible out of the corrupt message.
              However, be aware that a MDC protection failure may also mean that the message was tampered with inten‐
              tionally by an attacker.


       --no-default-keyring
              Do  not  add the default keyrings to the list of keyrings. Note that GnuPG will not operate without any
              keyrings, so if you use this option and do not provide alternate keyrings via  --keyring  or  --secret-
              keyring, then GnuPG will still use the default public or secret keyrings.

              Some applications don't need the user ID and the trust information given in the listings. By using this
              options they can get a faster listing. The exact behaviour of this option may  change  in  future  ver‐
              sions.  If you are missing some information, don't use this option.


       --no-literal
              This is not for normal use. Use the source to see for what it might be useful.


       --set-filesize
              This is not for normal use. Use the source to see for what it might be useful.


       --show-session-key
              Display  the  session  key used for one message. See --override-session-key for the counterpart of this
              option.

              We think that Key Escrow is a Bad Thing; however the user should have the freedom to decide whether  to
              go  to  prison  or to reveal the content of one specific message without compromising all messages ever
              encrypted for one secret key. DON'T USE IT UNLESS YOU ARE REALLY FORCED TO DO SO.


       --override-session-key string
              Don't use the public key but the session key string. The format of this string is the same as  the  one
              printed  by --show-session-key. This option is normally not used but comes handy in case someone forces
              you to reveal the content of an encrypted message; using this option you can do  this  without  handing
              out the secret key.


       --ask-sig-expire

       --no-ask-sig-expire
              When making a data signature, prompt for an expiration time. If this option is not specified, the expi‐
              ration time set via --default-sig-expire is used. --no-ask-sig-expire disables this option.


       --default-sig-expire
              The default expiration time to use for signature expiration. Valid values are "0" for no expiration,  a
              number  followed by the letter d (for days), w (for weeks), m (for months), or y (for years) (for exam‐
              ple "2m" for two months, or "5y" for five years), or an absolute date in the form YYYY-MM-DD.  Defaults
              to "0".


       --ask-cert-expire

       --no-ask-cert-expire
              When  making a key signature, prompt for an expiration time. If this option is not specified, the expi‐
              ration time set via --default-cert-expire is used. --no-ask-cert-expire disables this option.


       --default-cert-expire
              The default expiration time to use for key signature expiration.  Valid values are "0" for  no  expira‐
              tion,  a  number  followed  by the letter d (for days), w (for weeks), m (for months), or y (for years)
              (for example "2m" for two months, or "5y" for five years), or an absolute date in the form  YYYY-MM-DD.
              defaults to no.  Note that versions of GPG prior to 1.4.7 always allowed multiple messages.

              Warning: Do not use this option unless you need it as a temporary workaround!



       --enable-special-filenames
              This  options  enables  a  mode in which filenames of the form ‘-&n’, where n is a non-negative decimal
              number, refer to the file descriptor n and not to a file with that name.


       --no-expensive-trust-checks
              Experimental use only.


       --preserve-permissions
              Don't change the permissions of a secret keyring back to user read/write only. Use this option only  if
              you really know what you are doing.


       --default-preference-list string
              Set  the  list  of default preferences to string. This preference list is used for new keys and becomes
              the default for "setpref" in the edit menu.


       --default-keyserver-url name
              Set the default keyserver URL to name. This keyserver will be used as the keyserver URL when writing  a
              new self-signature on a key, which includes key generation and changing preferences.


       --list-config
              Display  various  internal configuration parameters of GnuPG. This option is intended for external pro‐
              grams that call GnuPG to perform tasks, and is thus not generally useful. See the file ‘doc/DETAILS’ in
              the  source  distribution  for the details of which configuration items may be listed. --list-config is
              only usable with --with-colons set.


       --gpgconf-list
              This command is similar to --list-config but in general only internally used by the gpgconf tool.


       --gpgconf-test
              This is more or less dummy action.  However it parses the configuration file and returns  with  failure
              if the configuration file would prevent gpg from startup.  Thus it may be used to run a syntax check on
              the configuration file.




   Deprecated options







       --always-trust
              Identical to --trust-model always. This option is deprecated.


       --show-notation

       --no-show-notation
              Show signature notations in the --list-sigs or --check-sigs listings as well as when verifying a signa‐
              ture with a notation in it. These options are deprecated. Use --list-options [no-]show-notation  and/or
              --verify-options [no-]show-notation instead.


       --show-policy-url

       --no-show-policy-url
              Show policy URLs in the --list-sigs or --check-sigs listings as well as when verifying a signature with
              a policy URL in it. These options are deprecated. Use --list-options [no-]show-policy-url and/or --ver‐
              ify-options [no-]show-policy-url instead.






EXAMPLES
       gpg -se -r Bob file
              sign and encrypt for user Bob


       gpg --clearsign file
              make a clear text signature


       gpg -sb file
              make a detached signature


       gpg -u 0x12345678 -sb file
              make a detached signature with the key 0x12345678


       gpg --list-keys user_ID
              show keys


       gpg --fingerprint user_ID
              show fingerprint


       gpg --verify pgpfile




       By key Id.
              This  format  is  deduced  from the length of the string and its content or 0x prefix. The key Id of an
              X.509 certificate are the low 64 bits of its SHA-1 fingerprint.  The use of key Ids is just a shortcut,
              for all automated processing the fingerprint should be used.

              When  using  gpg  an  exclamation mark (!) may be appended to force using the specified primary or sec‐
              ondary key and not to try and calculate which primary or secondary key to use.

              The last four lines of the example give the key ID in their long form as internally used by the OpenPGP
              protocol. You can see the long key ID using the option --with-colons.

         234567C4
         0F34E556E
         01347A56A
         0xAB123456

         234AABBCC34567C4
         0F323456784E56EAB
         01AB3FED1347A5612
         0x234AABBCC34567C4




       By fingerprint.
              This format is deduced from the length of the string and its content or the 0x prefix.  Note, that only
              the 20 byte version fingerprint is available with gpgsm (i.e. the SHA-1 hash of the certificate).

              When using gpg an exclamation mark (!) may be appended to force using the  specified  primary  or  sec‐
              ondary key and not to try and calculate which primary or secondary key to use.

              The best way to specify a key Id is by using the fingerprint.  This avoids any ambiguities in case that
              there are duplicated key IDs.

         1234343434343434C434343434343434
         123434343434343C3434343434343734349A3434
         0E12343434343434343434EAB3484343434343434
         0xE12343434343434343434EAB3484343434343434


       (gpgsm also accepts colons between each pair of hexadecimal digits because this is the  de-facto  standard  on
       how to present X.509 fingerprints.)


       By exact match on OpenPGP user ID.
              This is denoted by a leading equal sign. It does not make sense for X.509 certificates.

         =Heinrich Heine <[email protected]>


       By exact match on an email address.


       By exact match on the subject's DN.
              This  is  indicated  by  a  leading slash, directly followed by the RFC-2253 encoded DN of the subject.
              Note that you can't use the string printed by "gpgsm --list-keys" because that one  as  been  reordered
              and modified for better readability; use --with-colons to print the raw (but standard escaped) RFC-2253
              string

         /CN=Heinrich Heine,O=Poets,L=Paris,C=FR


       By exact match on the issuer's DN.
              This is indicated by a leading hash mark, directly followed by a slash and then  directly  followed  by
              the rfc2253 encoded DN of the issuer.  This should return the Root cert of the issuer.  See note above.

         #/CN=Root Cert,O=Poets,L=Paris,C=FR



       By exact match on serial number and issuer's DN.
              This is indicated by a hash mark, followed by the hexadecimal representation of the serial number, then
              followed by a slash and the RFC-2253 encoded DN of the issuer. See note above.

         #4F03/CN=Root Cert,O=Poets,L=Paris,C=FR


       By keygrip
              This is indicated by an ampersand followed by the 40 hex digits of a keygrip.  gpgsm prints the keygrip
              when using the command --dump-cert.  It does not yet work for OpenPGP keys.

         &D75F22C3F86E355877348498CDC92BD21010A480



       By substring match.
              This  is the default mode but applications may want to explicitly indicate this by putting the asterisk
              in front.  Match is not case sensitive.

         Heine
         *Heine



       Please note that we have reused the hash mark identifier which was used in old GnuPG versions to indicate  the
       so called local-id.  It is not anymore used and there should be no conflict when used with X.509 stuff.

       Using  the  RFC-2253  format  of DNs has the drawback that it is not possible to map them back to the original
       encoding, however we don't have to do this because our key database stores this encoding as meta data.





FILES

       so that newly created users start up with a working configuration.  For existing  users  the  a  small  helper
       script is provided to create these files (see: [addgnupghome]).

       For  internal  purposes  gpg2  creates  and  maintains a few other files; They all live in in the current home
       directory (see: [option --homedir]).  Only the gpg2 may modify these files.



       ~/.gnupg/secring.gpg
              The secret keyring.  You should backup this file.


       ~/.gnupg/secring.gpg.lock
              The lock file for the secret keyring.


       ~/.gnupg/pubring.gpg
              The public keyring.  You should backup this file.


       ~/.gnupg/pubring.gpg.lock
              The lock file for the public keyring.


       ~/.gnupg/trustdb.gpg
              The trust database.  There is no need to backup this file; it is better to backup the ownertrust values
              (see: [option --export-ownertrust]).


       ~/.gnupg/trustdb.gpg.lock
              The lock file for the trust database.


       ~/.gnupg/random_seed
              A file used to preserve the state of the internal random pool.


       /usr[/local]/share/gnupg/options.skel
              The skeleton options file.


       /usr[/local]/lib/gnupg/
              Default location for extensions.


       Operation is further controlled by a few environment variables:



       HOME   Used to locate the default home directory.


       GNUPGHOME
              If set directory used instead of "~/.gnupg".
              This  value  is passed via gpg-agent to pinentry.  It is useful to convey extra information to a custom
              pinentry.


       COLUMNS

       LINES  Used to size some displays to the full size of the screen.



       LANGUAGE
              Apart from its use by GNU, it is used in the W32  version  to  override  the  language  selection  done
              through  the  Registry.  If used and set to a valid and available language name (langid), the file with
              the translation is loaded from

              gpgdir/gnupg.nls/langid.mo.  Here gpgdir is the directory out of which the gpg binary has been  loaded.
              If  it  can't  be  loaded  the Registry is tried and as last resort the native Windows locale system is
              used.





BUGS
       On older systems this program should be installed as setuid(root). This is necessary  to  lock  memory  pages.
       Locking memory pages prevents the operating system from writing memory pages (which may contain passphrases or
       other sensitive material) to disk. If you get no warning message about insecure memory your  operating  system
       supports locking without being root. The program drops root privileges as soon as locked memory is allocated.

       Note also that some systems (especially laptops) have the ability to ``suspend to disk'' (also known as ``safe
       sleep'' or ``hibernate'').  This writes all memory to disk before going into a low power or even  powered  off
       mode.   Unless  measures  are  taken in the operating system to protect the saved memory, passphrases or other
       sensitive material may be recoverable from it later.

       Before you report a bug you should first search the mailing list archives  for  similar  problems  and  second
       check whether such a bug has already been reported to our bug tracker at http://bugs.gnupg.org .



SEE ALSO
       gpgv(1), gpgsm(1), gpg-agent(1)

       The  full  documentation  for  this tool is maintained as a Texinfo manual.  If GnuPG and the info program are
       properly installed at your site, the command

         info gnupg

       should give you access to the complete manual including a menu structure and an index.



GnuPG 2.0.22                                          2016-11-05                                              GPG2(1)