     [file defs.inc not included]

Invoking GPG
************

gpg2.1

synopsis

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

In contrast to the standalone command gpg from GnuPG 1.x, which is might be better suited for server and embedded platforms, the 2.x version is commonly installed under the name gpg2 and targeted to the desktop as it requires several other modules to be installed.

The old 1.x version will be kept maintained and it is possible to install both versions on the same system.  Documentation for the old GnuPG 1.x command is available as a man page and at see GnuPG 1 (gpg).

See Option Index, for an index to gpg2's commands and options.

commands

Commands
========

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

gpg2 may be run with no commands, in which case it will perform a reasonable action depending on the type of file it is given as input (an encrypted message is decrypted, a signature is verified, a file containing 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. Note 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 --symmetric together (for a signed message that may be decrypted via a secret key or a passphrase).  The key to be used for signing is chosen by default or can be set with the --local-user and --default-key options.

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

--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 GPGSYMENCALGO, 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 message that may be decrypted via a secret key or a passphrase).

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

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

--verify
     Assume that the first argument is a signed file and verify it without generating any output.  With no arguments, the signature packet is read from STDIN.  If only a one argument is given, it is expected to be a complete signature.

     With more than 1 argument, the first should be a detached signature and the remaining files ake up the the signed data. To read the signed data from STDIN, use - as the second filename.  For security reasons a detached signature cannot read the signed material from STDIN without denoting it in the above way.

     Note: If the option --batch is not used, gpg2 may assume that a single argument is a file with a detached signature and it will try to find a matching data file by stripping certain suffixes.  Using this historical feature to verify a detached signature is strongly discouraged; always specify the data file too.

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

--multifile
     This modifies certain other commands to accept multiple files for processing on the command line or read from STDIN with each filename on a separate line. This allows for many files to be processed at once. --multifile may currently be used along with --verify, --encrypt, and --decrypt. Note that --multifile --verify 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.

     Avoid using the output of this command in scripts or other programs 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. This command has the same effect as using --list-keys with --with-sig-list.

     For each signature listed, there are several flags in between the "sig" tag and keyid. These flags give additional information about each signature. From left to right, they are the numbers 1-3 for 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-policy-url), "N" for a signature that contains a notation (see --cert-notation), "X" for an eXpired signature (see --ask-cert-expire), and the numbers 1-9 or "T" for 10 and above to indicate trust signature levels (see the --edit-key command "tsign").

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

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

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

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

--list-packets
     List only the sequence of packets. This is mainly useful for debugging.  When used with option --verbose the actual MPI values are dumped and not only their lengths.

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

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

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

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

--export-secret-keys
--export-secret-subkeys
     Same as --export, but exports the secret keys instead.  The exported keys are written to STDOUT or to the file given with option --output.  This command is often used along with the option --armor to allow easy printing of the key for paper backup; however the external tool paperkey does a better job for creating backups on paper.  Note that exporting a secret key can be a security risk if the exported keys are send over an insecure channel.

     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 successfully import such a key.  Its intended use is to generated a full key with an additional signing subkey on a dedicated machine and then using this command to export the key without the primary key to the main machine.

     GnuPG may ask you to enter the passphrase for the key.  This is required because the internal protection method of the secret key is different from the one specified by the OpenPGP protocol.

--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 --import-options merge-only option which does not insert new keys but does only the merging of new signatures, user-IDs and subkeys.

--recv-keys key IDs
     Import the keys with the given key IDs from a keyserver. Option --keyserver must be used to give the 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-keyserver-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 methods 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 trustdb.  Example:

            gpg2 --export-ownertrust > otrust.txt

--import-ownertrust
     Update the trustdb with the ownertrust values stored in files (or STDIN if not given); existing values will be overwritten.  In case of a severely damaged trustdb and if you have a recent backup of the ownertrust values (e.g. in the file otrust.txt, you may re-create the trustdb using these commands:

            cd ~/.gnupg
            rm trustdb.gpg
            gpg2 --import-ownertrust < otrust.txt

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

--print-md algo
--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 count
     Emit COUNT random bytes of the given quality level 0, 1 or 2. If COUNT is not given or zero, an endless sequence of random bytes will be emitted.  If used with --armor the output will be base64 encoded.  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

--quick-gen-key user-id
     This is a simple command to generate a standard key with one user id. In contrast to --gen-key the key is generated directly without the need to answer a bunch of prompts.  Unless the option --yes is given, the key creation will be canceled if the given user id already exists in the key ring.

     If invoked directly on the console without any special options an answer to a ``Continue?'' style confirmation prompt is required.  In case the user id already exists in the key ring a second prompt to force the creation of the key will show up.

     If this command is used with --batch, --pinentry-mode has been set to loopback, and one of the passphrase options (--passphrase, --passphrase-fd, or passphrase-file) is used, the supplied passphrase is used for the new key and the agent does not ask for it.  To create a key without any protection --passphrase '' may be used.

--gen-key
     Generate a new key pair using the current default parameters.  This is the standard command to create a new key.

--full-gen-key
     Generate a new key pair with dialogs for all options.  This is an extended version of --gen-key.

     There is also a feature which allows you to create keys in batch mode. See the the manual section ``Unattended key generation'' on how to use this.

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

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

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

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

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

     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-revocable 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-revocable, and "t" (for trust) may be freely mixed and prefixed to "sign" to create a signature of any type desired.

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

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

     check
          Check the signatures on all selected user IDs.

     adduid
          Create an additional user ID.

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

     showphoto
          Display the selected photographic user ID.

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

     revuid
          Revoke a user ID or photographic user ID.

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

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

     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.

     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 preferred keyserver and signature notations (if any) are shown.

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

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

     addkey
          Add a subkey to this key.

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

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

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

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

     revkey
          Revoke a subkey.

     expire
          Change the key or subkey 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.

     trust
          Change the owner trust value for the key. 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.

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

     passwd
          Change the passphrase of the secret key.

     toggle
          This is dummy command which exists only for backward compatibility.

     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 signatures from each user ID except for the most recent self-signature.

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

     save
          Save all changes to the key rings and quit.

     quit
          Quit the program without updating the key rings.

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

     -
          No ownertrust assigned / not yet calculated.

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

     q
          Not enough information for calculation.

     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 version of the subcommand "sign" from --edit.

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

--quick-sign-key fpr [names]
--quick-lsign-key fpr [names]
     Directly sign a key from the passphrase without any further user interaction.  The fpr must be the verified primary fingerprint of a key in the local keyring. If no names are given, all useful user ids are signed; with given [names] only useful user ids matching one of theses names are signed.  The command --quick-lsign-key marks the signatures as non-exportable.  If such a non-exportable signature already exists the --quick-sign-key turns it into a exportable signature.

     This command uses reasonable defaults and thus does not provide the full flexibility of the "sign" subcommand from --edit-key. Its intended use is to help unattended key signing by utilizing a list of verified fingerprints.

--quick-adduid  USER-ID NEW-USER-ID
     This command adds a new user id to an existing key.  In contrast to the interactive sub-command adduid of --edit-key the NEW-USER-ID is added verbatim with only leading and trailing white space removed, it is expected to be UTF-8 encoded, and no checks on its form are applied.

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

options

Option Summary
==============

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

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

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

How to change the configuration
-------------------------------

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

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

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

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

--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.  Note that even with a filename given on the command line, gpg might still need to read from STDIN (in particular if gpg figures that the input is a detached signature and no data file has been specified).  Thus if you do not want to feed data via STDIN, you should connect STDIN to /dev/null.

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

--yes
     Assume "yes" on most questions.

--no
     Assume "no" on most questions.

--list-options parameters
     This is a space or comma delimited string that gives options used when listing keys and signatures (that is, --list-keys, --list-sigs, --list-public-keys, --list-secret-keys, and the --edit-key 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.  Does not work with --with-colons: see --attribute-fd for the appropriate way to get photo data for scripts and other frontends.

     show-usage
          Show usage information for keys and subkeys in the standard key listing.  This is a list of letters indicating the allowed usage for a key (E=encryption, S=signing, C=certification, A=authentication).  Defaults to no.

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

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

     show-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 subpackets to list. If no argument is passed, list all subpackets. Defaults to no. This option is only meaningful when using --with-colons along with --list-sigs or --check-sigs.

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

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

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

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

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

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

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

     show-primary-uid-only
          Show only the primary user ID during signature verification.  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 disclose information on when and what signatures are verified or to whom data is encrypted. This is similar to the "web bug" described for the auto-key-retrieve feature.

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

--enable-large-rsa
--disable-large-rsa
     With --gen-key and --batch, enable the creation of larger RSA secret keys than is generally recommended (up to 8192 bits).  These large keys are more expensive to use, and their signatures and certifications are also larger.

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

--photo-viewer string
     This is the command line that should be run to view a photo ID. "%i" will be expanded to a filename containing the photo. "%I" does the same, except the file will not be deleted once the viewer exits. Other flags are "%k" for the key ID, "%K" for the long key ID, "%f" for the key fingerprint, "%t" for the extension of the image type (e.g. "jpg"), "%T" for the MIME type of the image (e.g. "image/jpeg"), "%v" for the single-character calculated validity of the image being viewed (e.g. "f"), "%V" for the calculated validity as a string (e.g. "full"), "%U" for a base32 encoded hash of the user ID, and "%%" for an actual percent sign. If neither %i or %I are present, then the photo will be supplied to the viewer on standard input.

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

--exec-path string
     Sets a list of directories to search for photo viewers and keyserver helpers. If not provided, keyserver helpers use the compiled-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
     This is an obsolete option and ignored.  All secret keys are stored in the private-keys-v1.d directory below the GnuPG home directory.

--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).

          [file opt-homedir.texi not included]

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

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

     iso-8859-2
          The Latin 2 set.

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

     koi8-r
          The usual Russian set (rfc1489).

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

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

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

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

-z n
--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 compression 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 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 introduced by PGP 2.

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

     always
          Skip key validation and assume that used keys are always fully valid. You generally won't use this unless you are using some external validation scheme. This option also suppresses the "[uncertain]" tag printed with signature checks when there is no evidence that the user ID is bound to the key.  Note that this trust model still does not allow the use of expired, revoked, or disabled keys.

     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@example.com keys on the local keyring.  This option takes any number of the following mechanisms, in the order they are to be tried:

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

     pka
          Locate a key using DNS PKA.

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

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

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

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

     nodefault
          This flag disables the standard local key lookup, done before any of the mechanisms defined by the --auto-key-locate are tried.  The position of this mechanism in the list does not matter.  It is not required if local is also used.

     clear
          Clear all defined mechanisms.  This is useful to override mechanisms given in a config file.

--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 convenient) 16-character key ID. Add an "0x" to either to include an "0x" at the beginning of the key ID, as in 0x99242560.  Note that this option is ignored if the option --with-colons is used.

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

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

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

     include-revoked
          When searching for a key with --search-keys, include keys that are marked on the keyserver as revoked. Note that not all keyservers differentiate between revoked and unrevoked keys, and for such keyservers this option is meaningless. Note also that most keyservers do not have 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 keyserver to refresh the key from. In addition, if auto-key-retrieve is set, and the signature being verified has a preferred keyserver URL, then use that preferred keyserver to fetch the key from. Note that this option introduces a "web bug": The creator of the key can see when the keys is refreshed.  Thus this option is not enabled by default.

     honor-pka-record
          If auto-key-retrieve is set, and the signature being verified 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 targets. Note that this option is not used with HKP keyservers, as they do not support retrieving keys by subkey id.

     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 any proxy defined in dirmngr.conf.

     verbose
          This option has no more function since GnuPG 2.1.  Use the dirmngr configuration options instead.

     debug
          This option has no more function since GnuPG 2.1.  Use the dirmngr configuration options instead.

     check-cert
          This option has no more function since GnuPG 2.1.  Use the dirmngr configuration options instead.

     ca-cert-file
          This option has no more function since GnuPG 2.1.  Use the dirmngr configuration options instead.

--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).

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

--no-sig-create-check
     GnuPG normally verifies each signature right after creation to protect against bugs and hardware 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 creation needs manual interaction, this performance penalty does not matter in most settings.

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

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

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

--agent-program FILE
     Specify an agent program to be used for secret key operations.  The default value is determined by running gpgconf with the option --list-dirs.  Note that the pipe symbol (|) is used for a regression test suite hack and may thus not be used in the file name.

--dirmngr-program FILE
     Specify a dirmngr program to be used for keyserver access.  The default value is BINDIR/dirmngr.  This is only used as a fallback when the environment variable DIRMNGR_INFO is not set or a running dirmngr cannot be connected.

--no-autostart
     Do not start the gpg-agent or the dirmngr if it has not yet been started and its service is required.  This option is mostly useful on machines where the connection to gpg-agent has been redirected to another machines.  If dirmngr is required on the remote machine, it may be started manually using gpgconf --launch dirmngr.

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

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

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

--exit-on-status-write-error
     This option will cause write errors on the status FD to immediately terminate the process. That should 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 invocations. This makes random generation faster; however sometimes write operations are not desired. This option can be used to achieve that with the cost of slower random generation.

--no-greeting
     Suppress the initial copyright message.

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

--no-permission-warning
     Suppress the warning about unsafe file and home directory (--homedir) permissions. Note that the 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 warning may only be suppressed on the command line.

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

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

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

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

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 hidden "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 programs. Any time the group name is a recipient (-r or --recipient), it will be expanded to the values specified. Multiple groups with the same name are automatically merged into a single group.

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

--try-secret-key NAME
     For hidden recipients GPG needs to know the keys to use for trial decryption.  The key set with --default-key is always tried first, but this is often not sufficient.  This option allows to set more keys to be used for trial decryption.  Although any valid user-id specification may be used for NAME it makes sense to use at least the long keyid to avoid ambiguities.  Note that gpg-agent might pop up a pinentry for a lot keys to do the trial decryption.  If you want to stop all further trial decryption you may use close-window button instead of the cancel button.

--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 or --hidden-recipient) and might come handy in case where an encrypted message contains a bogus key ID.

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

Input and Output
----------------

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

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

--output FILE
-o FILE
     Write output to FILE.

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

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

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

     keep-ownertrust
          Normally possible still existing ownertrust values of a key are cleared if a key is imported.  This is in general desirable so that a formerly deleted key does not automatically gain an ownertrust values merely due to import.  On the other hand it is sometimes necessary to re-import a trusted set of keys again but keeping already assigned ownertrust values.  This can be achived by using this option.

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

     export-minimal
          Export the smallest key possible. This removes all signatures except the most recent self-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.

--print-pka-records
     Modify the output of the list commands to print PKA records suitable to put into DNS zone files.  An ORIGIN line is printed before each record to allow diverting the records to the corresponding zone file.

--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. Since GnuPG 2.0.10, this mode is always used and thus this option is obsolete; it does not harm to use it though.

--legacy-list-mode
     Revert to the pre-2.1 public key list mode.  This only affects the human readable output and not the machine interface (i.e. --with-colons).  Note that the legacy format does not allow to convey suitable information for elliptic curves.

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

--with-icao-spelling
     Print the ICAO spelling of the fingerprint in addition to the hex digits.

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

--with-secret
     Include info about the presence of a secret key in public key listings done with --with-colons.

OpenPGP protocol specific options.
----------------------------------

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

--force-v3-sigs
--no-force-v3-sigs

--force-v4-certs
--no-force-v4-certs
     These options are obsolete and have no effect since GnuPG 2.1.

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

--disable-mdc
     Disable the use of the modification detection code. Note that by using this option, the encrypted message becomes vulnerable to a message modification attack.

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

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

--s2k-cipher-algo name
     Use name as the cipher algorithm used to protect secret keys. The default cipher is GPGSYMENCALGO. This cipher is also used for symmetric encryption with a passphrase 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 symmetric encryption with a passphrase.

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

Compliance options
------------------

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

--gnupg
     Use standard GnuPG behavior. This is essentially OpenPGP behavior (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.  This option is deprecated will be removed in GnuPG 2.1.

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

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

     This option is deprecated will be removed in GnuPG 2.1.  The reason for dropping PGP-2 support is that the PGP 2 format is not anymore considered safe (for example due to the use of the broken MD5 algorithm). Note that the decryption of PGP-2 created messages will continue to work.

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

     This option implies --disable-mdc --escape-from-lines.

--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-level LEVEL
     Select the debug level for investigating problems. LEVEL may be a numeric value or by a keyword:

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

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

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

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

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

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

--debug FLAGS
     Set debugging flags. All flags are or-ed and FLAGS may be given in C syntax (e.g. 0x0042) or as a comma separated list of flag names. To get a list of all supported flags the single word "help" can be used.

--debug-all
     Set all useful debugging flags.

--debug-iolbf
     Set stdout into line buffered mode.  This option is only honored when given on the command line.

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

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

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

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

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

--log-file file
--logger-file file
     Same as --logger-fd, except the logger data is written to file file.  Note that --log-file is only implemented for GnuPG-2.

--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 behavior is not to use a comment string. --comment may be repeated multiple times to get multiple comment strings. --no-comments removes all comments.  It is a good idea to keep the length of a single comment below 60 characters to avoid problems with mail programs wrapping such lines.  Note that comment lines, like all other header lines, are not protected by the signature.

--emit-version
--no-emit-version
     Force inclusion of the version string in ASCII armored output.  If given once only the name of the program and the major number is emitted (default), given twice the minor is also emitted, given triple the micro is added, and given quad an operating system identification is also emitted.  --no-emit-version disables the version line.

--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.example.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 (rfc4880:5.2.3.16). --sig-notation sets a notation for data signatures. --cert-notation sets a notation for key signatures (certifications). --set-notation sets both.

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

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

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

--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.  Using the empty string for STRING effectively removes the filename from the output.

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

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

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

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

--compress-algo name
     Use compression algorithm name. "zlib" is RFC-1950 ZLIB compression. "zip" is RFC-1951 ZIP compression which is used by PGP. "bzip2" is a more modern compression scheme that can compress some things better than zip or zlib, but at the cost of more memory used during compression and decompression. "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 compression window size is not limited to 8k. BZIP2 may give even better compression results than that, but will use a significantly larger amount of memory while compressing and decompressing. This may be significant in low memory situations. Note, however, that PGP (all versions) only supports ZIP compression. Using any algorithm other than ZIP or "none" will make the message unreadable with PGP. In general, you do not want to use this option as it allows you to violate the OpenPGP standard. --personal-compress-preferences is the safe way to 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 signatures 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. (Using a little social engineering anyone who is able to decrypt the message can check whether one of the other recipients is the one he suspects.)  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 disables this option.

--passphrase-repeat n
     Specify how many times gpg2 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.

     Note that this passphrase is only used if the option --batch has also been given.  This is different from GnuPG version 1.x.

--passphrase-file file
     Read the passphrase from file file. Only the first line will be read from file file. This can only be used if only one passphrase is supplied. Obviously, a passphrase stored in a file is of questionable security if other users can read this file. Don't use this option if you can avoid it. Note that this passphrase is only used if the option --batch has also been given.  This is different from GnuPG version 1.x.

--passphrase string
     Use string as the passphrase. This can only be used if only one passphrase is supplied. Obviously, this is of very questionable security on a multi-user system. Don't use this option if you can avoid it. Note that this passphrase is only used if the option --batch has also been given.  This is different from GnuPG version 1.x.

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

     default
          Use the default of the agent, which is ask.

     ask
          Force the use of the Pinentry.

     cancel
          Emulate use of Pinentry's cancel button.

     error
          Return a Pinentry error (``No Pinentry'').

     loopback
          Redirect Pinentry queries to the caller.  Note that in contrast to Pinentry the user is not prompted again if he enters a bad password.

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

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

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

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

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

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

--ignore-crc-error
     The ASCII armor used by OpenPGP is protected by a CRC checksum against transmission errors. 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 failure may also mean that the message was tampered with intentionally by an attacker.

--allow-weak-digest-algos
     Signatures made with the broken MD5 algorithm are normally rejected with an ``invalid digest algorithm'' message.  This option allows the verification of signatures made with such weak algorithms.

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

--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 listings. 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.

     You can also use this option if you receive an encrypted message which is abusive or offensive, to prove to the administrators of the messaging system that the ciphertext transmitted corresponds to an inappropriate plaintext so they can take action against the offending user.

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

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

--default-sig-expire
     The default expiration time to use for signature expiration. Valid values are "0" for no expiration, a number followed by the letter d (for days), w (for weeks), m (for months), or y (for years) (for 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 prepared 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.

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

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

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

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

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

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

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

--list-gcrypt-config
     Display various internal configuration parameters of Libgcrypt.

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

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

Deprecated options
------------------

--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.

--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-policy-url and/or --verify-options [no-]show-policy-url instead.

files

Configuration files
===================

There are a few configuration files to control certain aspects of gpg2's operation. Unless noted, they are expected in the current home directory (see option --homedir).

gpg.conf
     This is the standard configuration file read by gpg2 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 gpg-option --options). You should backup this file.

Note that on larger installations, it is useful to put predefined files into the directory SYSCONFSKELDIR so that newly created users start up with a working configuration. For existing users a small helper script is provided to create these files (see addgnupghome).

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

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

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

~/.gnupg/pubring.kbx
     The public keyring using a different format.  This file is sharred with gpgsm.  You should backup this file.

~/.gnupg/pubring.kbx.lock
     The lock file for pubring.kbx.

~/.gnupg/secring.gpg
     A secret keyring as used by GnuPG versions before 2.1.  It is not used by GnuPG 2.1 and later.

~/.gnupg/.gpg-v21-migrated
     File indicating that a migration to GnuPG 2.1 has been done.

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

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

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

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

~/.gnupg/openpgp-revocs.d/
     This is the directory where gpg stores pre-generated revocation certificates.  The file name corresponds to the OpenPGP fingerprint of the respective key.  It is suggested to backup those certificates and if the primary private key is not stored on the disk to move them to an external storage device.  Anyone who can access theses files is able to revoke the corresponding key.  You may want to print them out. You should backup all files in this directory and take care to keep this backup closed away.

DATADIR/options.skel
     The skeleton options file.

LIBDIR/
     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
     This variable was used by GnuPG versions before 2.1

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 valid and available language name (LANGID), the file with the translation is loaded from

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

examples

Examples
========

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

gpg --clearsign file
     make a clear text signature

gpg -sb file
     make a detached signature

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

gpg --list-keys user_ID
     show keys

gpg --fingerprint user_ID
     show fingerprint

gpg --verify pgpfile
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 extension (".asc" or ".sig") of sigfile or by asking the user for the filename.

how to specify a user id

return value

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

WARNINGS
********

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

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

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

interoperability

INTEROPERABILITY WITH OTHER OPENPGP PROGRAMS
********************************************

GnuPG tries to be a very flexible implementation of the OpenPGP standard. In particular, GnuPG implements many of the optional parts of the standard, such as the SHA-512 hash, and the ZLIB and BZIP2 compression 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 preferences system that will always do the right thing and create messages that are usable by all recipients, regardless of which OpenPGP program they use. Only override this safe default if you really know what you are doing.

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.

bugs

BUGS
****

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

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

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

Unattended Usage
================

gpg is often used as a backend engine by other software.  To help with this a machine interface has been defined to have an unambiguous way to do this.  The options --status-fd and --batch are almost always required for this.

Unattended key generation
-------------------------

The command --gen-key may be used along with the option --batch for unattended key generation.  The parameters are either read from stdin or given as a file on the command line. The format of the parameter file is as follows:

  * Text only, line length is limited to about 1000 characters.

  * UTF-8 encoding must be used to specify non-ASCII characters.

  * Empty lines are ignored.

  * Leading and trailing while space is ignored.

  * A hash sign as the first non white space character indicates a comment line.

  * Control statements are indicated by a leading percent sign, the arguments are separated by white space from the keyword.

  * Parameters are specified by a keyword, followed by a colon.  Arguments are separated by white space.

  * The first parameter must be Key-Type; control statements may be placed anywhere.

  * The order of the parameters does not matter except for Key-Type which must be the first parameter.  The parameters are only used for the generated keyblock (primary and subkeys); parameters from previous sets are not used.  Some syntactically checks may be performed.

  * Key generation takes place when either the end of the parameter file is reached, the next Key-Type parameter is encountered or at the control statement %commit is encountered.

Control statements:

%echo TEXT
     Print TEXT as diagnostic.

%dry-run
     Suppress actual key generation (useful for syntax checking).

%commit
     Perform the key generation.  Note that an implicit commit is done at the next Key-Type parameter.

%pubring FILENAME
%secring FILENAME
     Do not write the key to the default or commandline given keyring but to FILENAME.  This must be given before the first commit to take place, duplicate specification of the same filename is ignored, the last filename before a commit is used.  The filename is used until a new filename is used (at commit points) and all keys are written to that file. If a new filename is given, this file is created (and overwrites an existing one).  For GnuPG versions prior to 2.1, both control statements must be given. For GnuPG 2.1 and later %secring is a no-op.

%ask-passphrase
%no-ask-passphrase
     This option is a no-op for GnuPG 2.1 and later.

%no-protection
     Using this option allows the creation of keys without any passphrase protection.  This option is mainly intended for regression tests.

%transient-key
     If given the keys are created using a faster and a somewhat less secure random number generator.  This option may be used for keys which are only used for a short time and do not require full cryptographic strength.  It takes only effect if used together with the control statement %no-protection.

General Parameters:

Key-Type: ALGO
     Starts a new parameter block by giving the type of the primary key. The algorithm must be capable of signing.  This is a required parameter.  ALGO may either be an OpenPGP algorithm number or a string with the algorithm name.  The special value default may be used for ALGO to create the default key type; in this case a Key-Usage shall not be given and default also be used for Subkey-Type.

Key-Length: NBITS
     The requested length of the generated key in bits.  The default is returned by running the command gpg2 --gpgconf-list.

Key-Grip: HEXSTRING
     This is optional and used to generate a CSR or certificate for an already existing key.  Key-Length will be ignored when given.

Key-Usage: USAGE-LIST
     Space or comma delimited list of key usages.  Allowed values are encrypt, sign, and auth.  This is used to generate the key flags.  Please make sure that the algorithm is capable of this usage.  Note that OpenPGP requires that all primary keys are capable of certification, so no matter what usage is given here, the cert flag will be on.  If no Key-Usage is specified and the Key-Type is not default, all allowed usages for that particular algorithm are used; if it is not given but default is used the usage will be sign.

Subkey-Type: ALGO
     This generates a secondary key (subkey).  Currently only one subkey can be handled.  See also Key-Type above.

Subkey-Length: NBITS
     Length of the secondary key (subkey) in bits.  The default is returned by running the command gpg2 --gpgconf-list".

Subkey-Usage: USAGE-LIST
     Key usage lists for a subkey; similar to Key-Usage.

Passphrase: STRING
     If you want to specify a passphrase for the secret key, enter it here. Default is to use the Pinentry dialog to ask for a passphrase.

Name-Real: NAME
Name-Comment: COMMENT
Name-Email: EMAIL
     The three parts of a user name.  Remember to use UTF-8 encoding here. If you don't give any of them, no user ID is created.

Expire-Date: ISO-DATE|(NUMBER[d|w|m|y])
     Set the expiration date for the key (and the subkey).  It may either be entered in ISO date format (e.g. "20000815T145012") or as number of days, weeks, month or years after the creation date.  The special notation "seconds=N" is also allowed to specify a number of seconds since creation.  Without a letter days are assumed.  Note that there is no check done on the overflow of the type used by OpenPGP for timestamps.  Thus you better make sure that the given value make sense.  Although OpenPGP works with time intervals, GnuPG uses an absolute value internally and thus the last year we can represent is 2105.

Creation-Date: ISO-DATE
     Set the creation date of the key as stored in the key information and which is also part of the fingerprint calculation.  Either a date like "1986-04-26" or a full timestamp like "19860426T042640" may be used. The time is considered to be UTC.  The special notation "seconds=N" may be used to directly specify a the number of seconds since Epoch (Unix time).  If it is not given the current time is used.

Preferences: STRING
     Set the cipher, hash, and compression preference values for this key. This expects the same type of string as the sub-command setpref in the --edit-key menu.

Revoker: ALGO:FPR [sensitive]
     Add a designated revoker to the generated key.  Algo is the public key algorithm of the designated revoker (i.e. RSA=1, DSA=17, etc.) FPR is the fingerprint of the designated revoker.  The optional sensitive flag marks the designated revoker as sensitive information.  Only v4 keys may be designated revokers.

Keyserver: STRING
     This is an optional parameter that specifies the preferred keyserver URL for the key.

Handle: STRING
     This is an optional parameter only used with the status lines KEY_CREATED and KEY_NOT_CREATED.  STRING may be up to 100 characters and should not contain spaces.  It is useful for batch key generation to associate a key parameter block with a status line.

Here is an example on how to create a key:

     $ cat >foo <<EOF
          %echo Generating a basic OpenPGP key
          Key-Type: DSA
          Key-Length: 1024
          Subkey-Type: ELG-E
          Subkey-Length: 1024
          Name-Real: Joe Tester
          Name-Comment: with stupid passphrase
          Name-Email: joe@foo.bar
          Expire-Date: 0
          Passphrase: abc
          %pubring foo.pub
          %secring foo.sec
          # Do a commit here, so that we can later print "done" :-)
          %commit
          %echo done
     EOF
     $ gpg2 --batch --gen-key foo
      [...]
     $ gpg2 --no-default-keyring --secret-keyring ./foo.sec \
            --keyring ./foo.pub --list-secret-keys
     /home/wk/work/gnupg-stable/scratch/foo.sec
     ------------------------------------------
     sec  1024D/915A878D 2000-03-09 Joe Tester (with stupid passphrase) <joe@foo.bar>
     ssb  1024g/8F70E2C0 2000-03-09

If you want to create a key with the default algorithms you would use these parameters:

          %echo Generating a default key
          Key-Type: default
          Subkey-Type: default
          Name-Real: Joe Tester
          Name-Comment: with stupid passphrase
          Name-Email: joe@foo.bar
          Expire-Date: 0
          Passphrase: abc
          %pubring foo.pub
          %secring foo.sec
          # Do a commit here, so that we can later print "done" :-)
          %commit
          %echo done

see also
     [file see-also-note.texi not included]