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gpg(1)                         GNU Privacy Guard                        gpg(1)




NAME

       gpg - OpenPGP encryption and signing tool


SYNOPSIS

       gpg [--homedir dir] [--options file] [options] command [args]




DESCRIPTION

       gpg  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.  gpg features complete key management and all bells and whis-
       tles you can expect from a decent OpenPGP implementation.

       This is the standalone version of gpg.  For desktop use you should con-
       sider using gpg2.









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 pro-
       gram 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 stan-
       dard. In particular, GnuPG implements many of the optional parts of the
       standard,  such as the SHA-512 hash, and the ZLIB and BZIP2 compression
       algorithms. 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 prefer-
       ences 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.

       If you absolutely must override the safe default, or if the preferences
       on a given key are invalid for some reason,  you  are  far  better  off
       using  the --pgp6, --pgp7, or --pgp8 options. These options are safe as
       they do not force any particular algorithms in  violation  of  OpenPGP,
       but rather reduce the available algorithms to a "PGP-safe" list.



COMMANDS

       Commands  are  not  distinguished from options except for the fact that
       only one command is allowed.

       gpg may be run with no commands, in which case it will perform  a  rea-
       sonable  action  depending on the type of file it is given as input (an
       encrypted message is decrypted, a signature is verified,  a  file  con-
       taining keys 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.  Not that you cannot abbreviate 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 --symmet-
              ric  together  (for a signed message that may be decrypted via a
              secret key or a passphrase).


       --clearsign
              Make a clear text signature. The content in a clear text  signa-
              ture  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.


       --detach-sign

       -b     Make a detached signature.


       --encrypt

       -e     Encrypt data. This option may be combined  with  --sign  (for  a
              signed  and  encrypted message), --symmetric (for a message that
              may be decrypted via a secret key or a  passphrase),  or  --sign
              and  --symmetric  together  (for  a  signed  message that may be
              decrypted via a secret key or a passphrase).


       --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 symmetrically 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 mes-
              sage 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 mes-
              sage.


       --verify
              Assume that the first argument is a signed file  or  a  detached
              signature  and  verify it without generating 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 argu-
              ment, 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.


       --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 --multifile --ver-
              ify may not be used with detached signatures.


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


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


       --decrypt-files
              Identical to --multifile --decrypt.


       --list-keys

       -k

       --list-public-keys
              List  all  keys from the public keyrings, or just the keys given
              on the command line.  -k is slightly different from  --list-keys
              in  that  it  allows  only for one argument and takes the second
              argument as the keyring to search.  This  is  for  command  line
              compatibility with PGP 2 and has been removed in gpg2.

              Avoid  using the output of this command in scripts or other pro-
              grams as it is likely to change as GnuPG  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 letters 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.

              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 certificate 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 contains a policy URL (see --cert-pol-
              icy-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.

              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 occured while checking the signature
              (e.g. a non supported algorithm).



       --fingerprint
              List all keys (or the specified ones) along with  their  finger-
              prints.  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.



       --card-edit
              Present a menu to work with a smartcard. The  subcommand  "help"
              provides  an  overview  on  available  commands.  For a detailed
              description,    please     see     the     Card     HOWTO     at
              http://www.gnupg.org/documentation/howtos.html#GnuPG-cardHOWTO .


       --card-status
              Show the content of the smart card.


       --change-pin
              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 and public 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  fin-
              gerprint.


       --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.  Finger-
              prints may be used instead of key IDs. Option  --keyserver  must
              be used to give the name of this keyserver. Don't send your com-
              plete keyring to a keyserver --- select only  those  keys  which
              are new or changed by you.


       --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-check-
              sum  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 synonym.

              There  are  a  few  other options which control how this command
              works.  Most notable here is the --keyserver-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 name of this keyserver.


       --refresh-keys
              Request  updates from a keyserver for keys that already exist on
              the local keyring. This is useful for updating a  key  with  the
              latest signatures, user IDs, etc. Calling this with no arguments
              will refresh the entire keyring. Option --keyserver must be used
              to  give the name of the keyserver for all keys that do not have
              preferred keyservers  set  (see  --keyserver-options  honor-key-
              server-url).


       --search-keys names
              Search  the  keyserver for the given names. Multiple names given
              here will be joined together to create the search string for the
              keyserver.   Option --keyserver must be used to give the name of
              this keyserver.  Keyservers that support different search  meth-
              ods  allow  using the syntax specified in "How to specify a user
              ID" below. Note that different keyserver types support different
              search methods. Currently 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 processing 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 trust DB.


       --import-ownertrust
              Update the trustdb with the ownertrust values  stored  in  files
              (or stdin if not given); existing values will be overwritten.


       --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

       --print-mds
              Print  message  digest  of algorithm ALGO for all given files or
              stdin.  With the second form  (or  a  deprecated  "*"  as  algo)
              digests for all available algorithms are printed.


       --gen-random 0|1|2
              Emit  count random bytes of the given quality level. If count is
              not given or zero, an endless sequence of random bytes  will  be
              emitted.   PLEASE,  don't  use this command unless you know what
              you are doing; it may remove precious entropy from the system!


       --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 distri-
              bution 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 manage-
              ment related tasks.  It expects the specification of  a  key  on
              the command line.



              sign   Make  a  signature  on key of user name If the key is not
                     yet signed by the default user (or the users  given  with
                     -u),  the  program  displays  the  information of the key
                     again, together with its fingerprint and asks whether  it
                     should be signed. This question is repeated for all users
                     specified with -u.


              lsign  Same as "sign"  but  the  signature  is  marked  as  non-
                     exportable  and  will  therefore never be used by others.
                     This may be used to make keys valid  only  in  the  local
                     environment.


              nrsign Same as "sign" but the signature is marked as non-revoca-
                     ble and can therefore never be revoked.


              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 distinct communities or groups.

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



              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.


              trust  Change  the  owner trust value. This updates the trust-db
                     immediately and no save is required.


              disable

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


              adduid Create an alternate 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  programs  will  display  your  JPEG
                     unchanged (GnuPG), and some programs will scale it to fit
                     in a dialog box (PGP).


              deluid Delete a 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.


              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.


              revuid Revoke a user id.


              addkey Add a subkey to this key.


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


              keytocard
                     Transfer the selected secret key (or the primary  key  if
                     no  key 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  trans-
                     ferred  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 encryp-
                     tion  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 pos-
                     sible  to  retract a subkey, once it has been send to the
                     public (i.e. to a keyserver).  In that  case  you  better
                     use revkey.


              addrevoker
                     Add  a  designated revoker. This takes one optional argu-
                     ment: "sensitive". If a designated revoker is  marked  as
                     sensitive,  it  will  not  be  exported  by  default (see
                     export-options).


              revkey Revoke a subkey.


              expire Change the key expiration time. If a subkey is  selected,
                     the  expiration time of this subkey will be changed. With
                     no selection, the key expiration of the  primary  key  is
                     changed.


              passwd Change the passphrase of the secret key.


              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 setting 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  regu-
                     lar user IDs.


              uid n  Toggle selection of user id with index n.  Use 0 to dese-
                     lect all.


              key n  Toggle selection of subkey with index n.  Use 0 to  dese-
                     lect all.


              check  Check all selected user ids.


              showphoto
                     Display the selected photographic user id.


              pref   List  preferences  from  the selected user ID. This shows
                     the actual preferences,  without  including  any  implied
                     preferences.


              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  (compression)  if  they  are  not   already
                     included  in  the  preference list. In addition, the pre-
                     ferred 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 call-
                     ing  setpref  with  "none"  as the argument sets an empty
                     preference list. Use gpg  --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.


              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.


              notation
                     Set a name=value notation for the specified  user  ID(s).
                     See --cert-notation for more on how this works. Setting a
                     value of "none" removes all notations, setting a notation
                     prefixed with a minus sign (-) removes that notation, and
                     setting a notation name  (without  the  =value)  prefixed
                     with a minus sign removes all notations with that name.


              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 calculations.   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  sig-
                     natures  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  sign-
                     ing subkeys. See --require-cross-certification.


              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. Selected keys or user ids are indicated by  an  aster-
              isk.  The  trust  value  is  displayed with the primary key: the
              first is the assigned owner trust and the second is  the  calcu-
              lated 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.


              n      Never trust this key.


              m      Marginally trusted.


              f      Fully trusted.


              u      Ultimately trusted.


       --sign-key name
              Signs a public key with your secret key. This is a shortcut ver-
              sion 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.







OPTIONS

       gpg  comes  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.


       --no-default-recipient
              Reset --default-recipient and --default-recipient-self.


       -v, --verbose
              Give more information during  processing.  If  used  twice,  the
              input data is listed in detail.


       --no-verbose
              Reset verbose level to 0.


       -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.


       --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  functions).   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.


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


              show-notations

              show-std-notations

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


              show-keyserver-urls

                     Show any preferred keyserver URL in  the  --list-sigs  or
                     --check-sigs listings. Defaults to no.


              show-uid-validity
                     Display  the  calculated  validity of user IDs during key
                     listings.  Defaults to no.


              show-unusable-uids
                     Show revoked  and  expired  user  IDs  in  key  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 subpack-
                     ets  to list. If no argument is passed, list all subpack-
                     ets. 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  nota-
                     tions  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.


              show-unusable-uids
                     Show revoked and expired user IDs during signature  veri-
                     fication.  Defaults to no.


              show-primary-uid-only
                     Show  only the primary user ID during signature verifica-
                     tion.  That is all the AKA lines as well as photo Ids are
                     not shown with the signature verification status.


              pka-lookups
                     Enable  PKA lookups to verify sender addresses. Note that
                     PKA is based on DNS, and so enabling this option may dis-
                     close  information  on when and what signatures are veri-
                     fied 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
              Enables  new-style  DSA keys which (unlike the old style) may be
              larger than 1024  bit  and  use  hashes  other  than  SHA-1  and
              RIPEMD/160.  Note that very few programs currently support these
              keys and signatures from them.


       --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  exten-
              sion  of  the image type (e.g. "jpg"), "%T" for the MIME type of
              the image (e.g. "image/jpeg"), 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  key-
              server  helpers. If not provided, keyserver helpers use the com-
              piled-in default directory, and  photo  viewers  use  the  $PATH
              environment  variable.   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 keyserver --recv-from) will
              go to this keyring.


       --trustdb-name file
              Use file instead of the default trustdb. 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).



       --homedir dir
              Set the name of the home directory to dir. If his option is  not
              used,  the  home  directory  defaults to `~/.gnupg'.  It is only
              recognized when given on the command line.   It  also  overrides
              any  home  directory  stated  through  the  environment variable
              `GNUPGHOME' or (on W32 systems) by means on the  Registry  entry
              HKCU\Software\GNU\GnuPG:HomeDir.



       --pcsc-driver file
              Use  file to access the smartcard reader. The current default is
              `libpcsclite.so.1'   for    GLIBC    based    systems,    `/Sys-
              tem/Library/Frameworks/PCSC.framework/PCSC'  for MAC OS X, `win-
              scard.dll' for Windows and `libpcsclite.so' for other systems.


       --disable-ccid
              Disable the integrated support for CCID compliant readers.  This
              allows  to  fall  back  to  one of the other drivers even if the
              internal CCID driver can handle the reader. Note, that CCID sup-
              port is only available if libusb was available at build time.


       --reader-port number_or_string
              This  option  may be used to specify the port of the card termi-
              nal. A value of 0 refers to the first serial device;  add  32768
              to  access USB devices. The default is 32768 (first USB device).
              PC/SC or CCID readers might need a string here; run the  program
              in  verbose mode to get a list of available readers. The default
              is then the first reader found.


       --display-charset name
              Set the name of the native character set. This is used  to  con-
              vert  some  informational  strings  like  user IDs to the proper
              UTF-8 encoding.  Note that this has nothing to do with the char-
              acter  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

       --compress-level n

       --bzip2-compress-level n
              Set compression level to n for  the  ZIP  and  ZLIB  compression
              algorithms.  The default is to use the default compression level
              of zlib (normally 6). --bzip2-compress-level sets  the  compres-
              sion  level for the BZIP2 compression algorithm (defaulting to 6
              as well). This is a different option from --compress-level since
              BZIP2  uses  a  significant amount of memory for each additional
              compression level.  -z sets both. A value of 0  for  n  disables
              compression.


       --bzip2-decompress-lowmem
              Use a different decompression method for BZIP2 compressed files.
              This alternate method uses a bit more than half the memory,  but
              also  runs  at  half the speed. This is useful under extreme low
              memory circumstances 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 that 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 your own  secret  keys.
              This option is useful if you don't want to keep your secret keys
              (or one of them) online but still want to be able to  check  the
              validity of a given recipient's or signator's key.


       --trust-model pgp|classic|direct|always|auto
              Set what trust model GnuPG should follow. The models are:



              pgp    This  is  the Web of Trust combined with trust signatures
                     as used in PGP 5.x and later. This is the  default  trust
                     model when creating a new trust database.


              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  calcu-
                     lated 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 signa-
                     ture 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 "user@example.com" form), and there  are  no  user@exam-
              ple.com  keys on the local keyring. This option takes any number
              of the following arguments, in the order they are to be tried:



              cert   locate a key using DNS  CERT,  as  specified  in  2538bis
                     (currently       in       draft):      http://www.josefs-
                     son.org/rfc2538bis/


              pka    locate a key using DNS PKA.


              ldap   locate a 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 key-
                     server.


       --keyid-format short|0xshort|long|0xlong
              Select how to  display  key  IDs.  "short"  is  the  traditional
              8-character key ID. "long" is the more accurate (but less conve-
              nient) 16-character key ID. Add an "0x" to either to include  an
              "0x" at the beginning of the key ID, as in 0x99242560.


       --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.  Key-
              server  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 particular keyserver.

              Most keyservers synchronize with each other, so there is  gener-
              ally no need to send keys to more than one server. The keyserver
              hkp://subkeys.pgp.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 prepended 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  export-
              ing  (--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
                     cryptographic  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 naturally 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 key-
                     server 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  key-
                     server to fetch the key from. Defaults to yes.


              honor-pka-record
                     If auto-key-retrieve is set, and the signature being ver-
                     ified has a PKA record, then use the PKA  information  to
                     fetch the key. Defaults to yes.


              include-subkeys
                     When  receiving  a key, include subkeys as potential tar-
                     gets. Note that this option is not  used  with  HKP  key-
                     servers, as they do not support retrieving keys by subkey
                     id.


              use-temp-files
                     On most Unix-like platforms, GnuPG communicates with  the
                     keyserver  helper  program  via  pipes, which is the most
                     efficient method. This option forces GnuPG to use  tempo-
                     rary  files  to  communicate.  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 key-
                     server 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.


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


       --marginals-needed n
              Number of marginally trusted users to introduce a new key signer
              (defaults to 3)


       --max-cert-depth n
              Maximum depth of a certification chain (default is 5).


       --simple-sk-checksum
              Secret keys are integrity protected by using a  SHA-1  checksum.
              This  method is part of the upcoming enhanced OpenPGP specifica-
              tion but GnuPG already uses it as a countermeasure against  cer-
              tain  attacks.   Old applications don't understand this new for-
              mat, so this option may be used to switch back to the old behav-
              iour.  Using  this option bears a security risk. Note that using
              this option only takes effect when 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 modi-
              fications,  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 pub-
              lic keyring.


       --no-sig-create-check
              GnuPG normally verifies each signature right after  creation  to
              protect  against bugs and hardware malfunctions 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 cre-
              ation  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 disables this option.


       --use-agent

       --no-use-agent
              Try to use the GnuPG-Agent.  With this option, GnuPG first tries
              to connect to the agent before it asks for a  passphrase.  --no-
              use-agent disables this option.


       --gpg-agent-info
              Override  the  value  of  the  environment  variable been given.
              Given that this option is not anymore used by gpg2, it should be
              avoided if possible.


       --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 immedi-
              ately terminate the process. That should in fact be the  default
              but  it  never  worked  this  way  and thus we need an option to
              enable this, so that the change won't break  applications  which
              close  their  end of a status fd connected pipe too early. Using
              this option along with --enable-progress-filter may be  used  to
              cleanly cancel long running gpg operations.


       --limit-card-insert-tries n
              With  n  greater than 0 the number of prompts asking to insert a
              smartcard gets limited to N-1. Thus with a value of 1 gpg  won't
              at  all  ask  to  insert  a  card  if  none has been inserted at
              startup. This option is useful in the configuration file in case
              an  application  does  not  know about the smartcard support and
              waits ad infinitum for an inserted card.


       --no-random-seed-file
              GnuPG uses a file to store its internal random pool over invoca-
              tions.   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  permission  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 system 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 warn-
              ing 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 sub-
              keys that can sign.  Defaults  to  --require-cross-certification
              for gpg.


       --expert

       --no-expert
              Allow  the user to do certain nonsensical or "silly" things like
              signing an expired or revoked key, or certain potentially incom-
              patible things like generating unusual key types. This also dis-
              ables 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.








   Key related options




       --recipient name

       -r     Encrypt  for  user id name. If this option or --hidden-recipient
              is not specified, GnuPG asks for the 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 hid-
              den "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.


       --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 pro-
              grams.   Any time the group name is a recipient (-r or --recipi-
              ent), 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 arguments.


       --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  over-
              rides --default-key.


       --try-all-secrets
              Don't  look  at  the key ID as stored in the message but try all
              secret keys in turn to  find  the  right  decryption  key.  This
              option  forces  the  behaviour  as  used by anonymous recipients
              (created by using --throw-keyids) and might come handy  in  case
              where an encrypted message contains a bogus key ID.








   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.


              repair-pks-subkey-bug
                     During import, attempt to repair the damage caused by the
                     PKS keyserver bug (pre version 0.9.6) that  mangles  keys
                     with  multiple  subkeys. Note that this cannot completely
                     repair the damaged key as some crucial data is removed by
                     the  keyserver,  but  it  does at least give you back one
                     subkey. Defaults to no for regular --import  and  to  yes
                     for keyserver --recv-keys.


              merge-only
                     During import, allow key updates to existing keys, but do
                     not allow any new keys to be imported. 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 signa-
                     tures  except the most recent self-signature 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 unattended 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 run-
                     ning 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 signa-
                     tures  except the most recent self-signature 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-colons
              Print key listings delimited by colons.  Note  that  the  output
              will  be  encoded  in  UTF-8 regardless of any --display-charset
              setting. This format is useful when GnuPG is called from scripts
              and  other  programs as it is easily machine parsed. The details
              of this format are documented in the file  `doc/DETAILS',  which
              is included in the GnuPG source distribution.


       --fixed-list-mode
              Do  not  merge  primary  user ID and primary key in --with-colon
              listing  mode  and  print  all  timestamps  as   seconds   since
              1970-01-01.


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





   OpenPGP protocol specific options.




       -t, --textmode

       --no-textmode
              Treat input files as text and store them in the OpenPGP  canoni-
              cal  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.

              If  -t  (but  not --textmode) is used together with armoring and
              signing, this  enables  clearsigned  messages.  This  kludge  is
              needed for command-line compatibility with command-line versions
              of PGP; normally you would use --sign or --clearsign  to  select
              the type of the signature.


       --force-v3-sigs

       --no-force-v3-sigs
              OpenPGP  states that an implementation should generate v4 signa-
              tures 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 --ask-sig-expire, --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.


       --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  block-
              size  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 message becomes vulnerable to a
              message modification attack.


       --personal-cipher-preferences string
              Set the list of personal cipher preferences to string.  Use  gpg
              --version to get a list of available algorithms, and use none to
              set no preference at all.  This allows the  user  to  factor  in
              their  own  preferred  algorithms when algorithms are chosen via
              recipient key preferences.  The most  highly  ranked  cipher  in
              this list is also used for the --symmetric encryption command.


       --personal-digest-preferences string
              Set  the list of personal digest preferences to string.  Use gpg
              --version to get a list of available algorithms, and use none to
              set  no  preference  at  all.  This allows the user to factor in
              their own preferred algorithms when algorithms  are  chosen  via
              recipient  key preferences.  The most highly ranked digest algo-
              rithm in this list is algo used when signing without  encryption
              (e.g. --clearsign or --sign). The default value is SHA-1.


       --personal-compress-preferences string
              Set the list of personal compression preferences to string.  Use
              gpg --version to get a list of  available  algorithms,  and  use
              none  to set no preference at all.  This allows the user to fac-
              tor in their own preferred algorithms when algorithms are chosen
              via  recipient key preferences.  The most highly ranked compres-
              sion algorithm in this list is  algo  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  con-
              ventional   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,  and
              the  default  is  65536.   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 PROGRAMS section below before using one of these options.



       --gnupg
              Use  standard GnuPG behavior. This is essentially OpenPGP behav-
              ior (see --openpgp), but with some  additional  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 in the
              gpg.conf file.


       --openpgp
              Reset all packet, cipher and digest options  to  strict  OpenPGP
              behavior.  Use  this  option  to reset all previous options like
              --s2k-*, --cipher-algo,  --digest-algo  and  --compress-algo  to
              OpenPGP compliant values. All PGP workarounds are disabled.


       --rfc4880
              Reset  all  packet, cipher and digest options to strict RFC-4880
              behavior.  Note  that  this  is  currently  the  same  thing  as
              --openpgp.


       --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 han-
              dle.  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
              --no-sk-comment  --escape-from-lines  --force-v3-sigs  --cipher-
              algo  IDEA  --digest-algo  MD5 --compress-algo ZIP. It also dis-
              ables --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 --no-sk-comment --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 semantic of this command may be
              extended  in  the  future.  Currently  it  only skips the actual
              decryption pass and therefore enables  a  fast  listing  of  the
              encryption keys.


       -i

       --interactive
              Prompt before overwriting any files.


       --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.


       --debug-ccid-driver
              Enable debug output from the included  CCID  driver  for  smart-
              cards.   Note that this option is only available on some system.


       --enable-progress-filter
              Enable certain PROGRESS status outputs. This option allows fron-
              tends  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.


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


       --attribute-fd n
              Write attribute subpackets to the file  descriptor  n.  This  is
              most  useful for use with --status-fd, since the status messages
              are needed to separate  out  the  various  subpackets  from  the
              stream delivered to the file descriptor.


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


       --comment string

       --no-comments
              Use string as a comment string  in  clear  text  signatures  and
              ASCII armored messages or keys (see --armor). The default behav-
              ior 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 characters or spaces, and
              must contain a '@' character in  the  form  keyname@domain.exam-
              ple.com  (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 (rfc2440:5.2.3.15).
              --sig-notation sets a notation for data signatures. --cert-nota-
              tion 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 fin-
              gerprint  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 mak-
              ing the signature (which might be a subkey), "%p" into the  fin-
              gerprint  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 (rfc2440:5.2.3.19).
              If you prefix it with an exclamation mark (!),  the  policy  URL
              packet will be flagged as critical. --sig-policy-url sets a pol-
              icy 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.


       --sig-keyserver-url string
              Use  string as a preferred keyserver URL for data signatures. If
              you prefix it with an exclamation mark (!),  the  keyserver  URL
              packet will be flagged as critical.

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


       --set-filename string
              Use string as the filename  which  is  stored  inside  messages.
              This  overrides the default, which is to use the actual filename
              of the file being encrypted.


       --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 the "secure viewer" with a  Tempest-resis-
              tant  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  com-
              mand --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.  --per-
              sonal-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 algo-
              rithms. 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 compres-
              sion.  "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. "uncompressed"
              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  com-
              pression  window  size is not limited to 8k. BZIP2 may give even
              better compression results than that, but will  use  a  signifi-
              cantly larger amount of memory while compressing and decompress-
              ing. 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  mes-
              sage  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 accomplish
              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  signa-
              tures you make, or quite possibly your entire key.


       --disable-cipher-algo name
              Never allow the use of name as cipher algorithm.  The given name
              will not be checked so that a later loaded algorithm will  still
              get disabled.


       --disable-pubkey-algo name
              Never  allow the use of name as public key algorithm.  The given
              name will not be checked so that a later loaded  algorithm  will
              still get disabled.


       --throw-keyids

       --no-throw-keyids
              Do  not  put the recipient key IDs into encrypted messages. This
              helps to hide the receivers of the  message  and  is  a  limited
              countermeasure  against traffic analysis. 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 signature. Note that all other PGP versions  do  it
              this  way  too.  Enabled by default. --no-escape-from-lines dis-
              ables this option.


       --passphrase-repeat n
              Specify how many times gpg will  request  a  new  passphrase  be
              repeated.   This  is  useful  for helping memorize 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.


       --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.


       --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.


       --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  envi-
              ronments  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 sig-
              nature 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  you 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. Occasionally the CRC gets mangled
              somewhere on the transmission channel  but  the  actual  content
              (which  is  protected  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 fail-
              ure may also mean that the message was tampered with  intention-
              ally 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  pub-
              lic or secret keyrings.


       --skip-verify
              Skip  the  signature verification step. This may be used to make
              the decryption faster  if  the  signature  verification  is  not
              needed.


       --with-key-data
              Print  key listings delimited by colons (like --with-colons) and
              print the public key data.


       --fast-list-mode
              Changes the output of the list commands to work faster; this  is
              achieved  by  leaving  some parts empty. Some applications don't
              need the user ID and the trust information given  in  the  list-
              ings.  By  using this options they can get a faster listing. The
              exact behaviour of this option may change  in  future  versions.
              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 mes-
              sage; 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  expiration  time  set  via
              --default-sig-expire  is used. --no-ask-sig-expire disables this
              option. Note that by default, --force-v3-sigs is set which  also
              disables this option. If you want signature expiration, you must
              set --no-force-v3-sigs as well as turning --ask-sig-expire on.


       --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  example  "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  expiration  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 expiration, 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
              "0".


       --allow-secret-key-import
              This is an obsolete option and is not used anywhere.


       --allow-multiple-messages

       --no-allow-multiple-messages
              Allow  processing  of  multiple  OpenPGP messages contained in a
              single file or stream.  Some programs that call GPG are not pre-
              pared  to  deal with multiple messages being processed together,
              so this option defaults to no.  Note that versions of GPG  prior
              to 1.4.7 always allowed multiple messages.


       --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 programs that call GnuPG to per-
              form  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 con-
              figuration 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




       --load-extension name
              Load an extension module. If name does not contain a slash it is
              searched  for  in  the directory configured when GnuPG was built
              (generally "/usr/local/lib/gnupg"). Extensions are not generally
              useful anymore, and the use of this option is deprecated.


       --show-photos

       --no-show-photos
              Causes  --list-keys,  --list-sigs,  --list-public-keys,  --list-
              secret-keys, and verifying a signature to also display the photo
              ID  attached  to the key, if any. See also --photo-viewer. These
              options  are  deprecated.  Use  --list-options  [no-]show-photos
              and/or --verify-options [no-]show-photos instead.


       --show-keyring
              Display  the  keyring  name  at the head of key listings to show
              which keyring a given key resides on. This option is deprecated:
              use --list-options [no-]show-keyring instead.


       --ctapi-driver file
              Use  file to access the smartcard reader. The current default is
              `libtowitoko.so'. Note that the use of this interface is  depre-
              cated; it may be removed in future releases.


       --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 signature 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-pol-
              icy-url and/or --verify-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 --list-keys user_ID
              show keys


       gpg --fingerprint user_ID
              show fingerprint


       gpg --verify pgpfile

       gpg --verify sigfile
              Verify the signature of the file but do not output the data. The
              second  form  is  used for detached signatures, where sigfile is
              the detached signature (either ASCII armored or binary) and  are
              the  signed  data;  if  this  is not given, the name of the file
              holding the signed data is constructed by cutting off the exten-
              sion (".asc" or ".sig") of sigfile or by asking the user for the
              filename.





HOW TO SPECIFY A USER ID

       There are different ways to specify a user ID to GnuPG.  Some  of  them
       are  only  valid  for  gpg others are only good for gpgsm.  Here is the
       entire list of ways to specify a key:



       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 secondary 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 secondary 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  finger-
       prints.)


       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 <heinrichh@uni-duesseldorf.de>


       By exact match on an email address.
              This is indicated by enclosing the email address  in  the  usual
              way with left and right angles.

         <heinrichh@uni-duesseldorf.de>



       By word match.
              All words must match exactly (not case sensitive) but can appear
              in any order in the user ID or a subjects name.  Words  are  any
              sequences  of letters, digits, the underscore and all characters
              with bit 7 set.

         +Heinrich Heine duesseldorf


       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 possi-
       ble 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

       There are a few configuration files to control certain aspects of gpg's
       operation.  Unless  noted, they are expected in the current home direc-
       tory (see: [option --homedir]).



       gpg.conf
              This is the standard configuration file read by gpg on  startup.
              It may contain any valid long option; the leading two dashes may
              not be entered and the option  may  not  be  abbreviated.   This
              default name may be changed on the command line (see: [option
                --options]).


       Note that on larger installations, it is useful to put predefined files
       into the directory `/etc/skel/.gnupg/'  so  that  newly  created  users
       start up with a working configuration.

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



       ~/.gnupg/secring.gpg
              The secret keyring.


       ~/.gnupg/secring.gpg.lock
              and the lock file


       ~/.gnupg/pubring.gpg
              The public keyring


       ~/.gnupg/pubring.gpg.lock
              and the lock file


       ~/.gnupg/trustdb.gpg
              The trust database


       ~/.gnupg/trustdb.gpg.lock
              and the lock file


       ~/.gnupg/random_seed
              used to preserve the internal random pool


       /usr[/local]/share/gnupg/options.skel
              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".


       GPG_AGENT_INFO
              Used  to locate the gpg-agent.  This is only honored when --use-
              agent is set.  The value consists of 3 colon  delimited  fields:
              The  first is the path to the Unix Domain Socket, the second the
              PID of the gpg-agent and the protocol version  which  should  be
              set  to 1. When starting the gpg-agent as described in its docu-
              mentation, this variable is set to the correct value. The option
              --gpg-agent-info can be used to override it.


       PINENTRY_USER_DATA
              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 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 laoded.  If it can't be loaded the
              Registry is tried as a fallback.






BUGS

       On many 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.



SEE ALSO

       gpgv(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 struc-
       ture and an index.



GnuPG 1.4.9                       2008-09-19                            gpg(1)

gnupg 1.4.9 - Generated Sun Sep 28 10:11:21 CDT 2008
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