GPG(1) GNU Privacy Guard 1.4 GPG(1)

NAME

gpg - OpenPGP encryption and signing tool

SYNOPSIS

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

DESCRIPTION

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

This is the standalone version of gpg. For desktop use you should
consider using gpg2 from the GnuPG-2 package
([On some platforms gpg2 is installed under the name gpg]).

RETURN VALUE

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

WARNINGS

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

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

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

INTEROPERABILITY

GnuPG tries to be a very flexible implementation of the OpenPGP
standard. In particular, GnuPG implements many of the optional parts
of the standard, such as the SHA-512 hash, and the ZLIB and BZIP2
compression 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.

COMMANDS

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

gpg may be run with no commands, in which case it will perform a
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 AES128, 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 make 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, gpg 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.

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

Avoid using the output of this command in scripts or other
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.

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.

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).


--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.


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


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


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


--export
Either export all keys from all keyrings (default keyrings and
those registered via option --keyring), or if at least one
name is given, those of the given name. The 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.

See the option --simple-sk-checksum if you want to import an
exported secret key into ancient OpenPGP implementations.


--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:
gpg --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
gpg --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


--gen-key
Generate a new key pair using the current default parameters.
This is the standard command to create a new 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 gpg --version to get a list
of available algorithms. Note that while you can change
the preferences on an attribute user ID (aka "photo
ID"), GnuPG does not select keys via attribute user IDs
so these preferences will not be used by GnuPG.

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


addkey Add a subkey to this key.


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


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


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


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


revkey Revoke a subkey.


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 Toggle between public and secret key listing.


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


minimize
Make the key as small as possible. This removes all
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.

OPTIONS

gpg 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. This option is commonly used
for unattended operations.

WARNING: Unattended operation bears a higher risk of being
exposed to security attacks. In particular any unattended use
of GnuPG which involves the use of secret keys should take
care not to provide an decryption oracle. There are several
standard pre-cautions against being used as an oracle. For
example never return detailed error messages or any
diagnostics printed by your software to the remote site.
Consult with an expert in case of doubt.

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
Same as --keyring but for the secret keyrings.


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


--trustdb-name file
Use file instead of the default trustdb. If file begins with a
tilde and a slash, these are replaced by the $HOME directory.
If the filename does not contain a slash, it is assumed to be
in the GnuPG home directory (`~/.gnupg' if --homedir or
$GNUPGHOME is not used).


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

On Windows systems it is possible to install GnuPG as a
portable application. In this case only this command line
option is considered, all other ways to set a home directory
are ignored.

To install GnuPG as a portable application under Windows,
create an empty file name `gpgconf.ctl' in the same directory
as the tool `gpgconf.exe'. The root of the installation is
than that directory; or, if `gpgconf.exe' has been installed
directly below a directory named `bin', its parent directory.
You also need to make sure that the following directories
exist and are writable: `ROOT/home' for the GnuPG home and
`ROOT/var/cache/gnupg' for internal cache files.


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


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


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


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


include-revoked
When searching for a key with --search-keys, include
keys that are marked on the keyserver as revoked. Note
that not all keyservers differentiate between revoked
and unrevoked keys, and for such keyservers this option
is meaningless. Note also that most keyservers do not
have 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. Defaults to
yes.


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.


use-temp-files
On most Unix-like platforms, GnuPG communicates with
the keyserver helper program via pipes, which is the
most efficient method. This option forces GnuPG to use
temporary files to communicate. On some platforms (such
as Win32 and RISC OS), this option is always enabled.


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


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


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


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


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


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


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


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

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


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


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


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


--simple-sk-checksum
Secret keys are integrity protected by using a SHA-1 checksum.
This method is part of the upcoming enhanced OpenPGP
specification but GnuPG already uses it as a countermeasure
against certain attacks. Old applications don't understand
this new format, so this option may be used to switch back to
the old behaviour. Using this option bears a security risk.
Note that using this option only takes effect when the secret
key is encrypted - the simplest way to make this happen is to
change the passphrase on the key (even changing it to the same
value is acceptable).


--no-sig-cache
Do not cache the verification status of key signatures.
Caching gives a much better performance in key listings.
However, if you suspect that your public keyring is not save
against write 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
This options is obsolete. It has no function.


--auto-check-trustdb

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


--use-agent

--no-use-agent
Try to use the GnuPG-Agent. With this option, GnuPG first
tries to connect to the agent before it asks for a passphrase.
--no-use-agent disables this option. Note, that the tool gpg-
preset-passphrase, which comes with GnuPG-2, cannot be used to
preset a passphrase for this version of GnuPG.


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


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


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


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


--exit-on-status-write-error
This option will cause write errors on the status FD to
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 gpg.


--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-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.

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


export-clean
Compact (remove all signatures from) user IDs on the
key being exported if the user IDs are not usable.
Also, do not export any signatures that are not usable.
This includes signatures that were issued by keys that
are not present on the keyring. This option is the same
as 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.


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


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


OpenPGP protocol specific options.


-t, --textmode

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

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


--force-v3-sigs

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


--force-v4-certs

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


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


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


--personal-cipher-preferences string
Set the list of personal cipher preferences to string. Use
gpg --version to get a list of available algorithms, and use
none to set no preference at all. This allows the user to
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
gpg --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 gpg --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 AES128. This cipher is also used for
conventional encryption if --personal-cipher-preferences and
--cipher-algo is not given.


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


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


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

Compliance options

These options control what GnuPG is compliant to. Only one of these
options may be active at a time. Note that the default setting of
this is nearly always the correct one. See the INTEROPERABILITY WITH
OTHER OPENPGP 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 --force-
v3-sigs.


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


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


Doing things one usually doesn't want to do.


-n

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


--list-only
Changes the behaviour of some commands. This is like --dry-run
but different in some cases. The semantic of this command may
be extended in the future. Currently it only skips the actual
decryption pass and therefore enables a fast listing of the
encryption keys.


-i

--interactive
Prompt before overwriting any files.


--debug-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).


--debug-all
Set all useful debugging flags.


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


--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, 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
(default) 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.


--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 enables overwriting 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 gpg will request a new passphrase be
repeated. This is useful for helping memorize a passphrase.
Defaults to 1 repetition.


--passphrase-fd n
Read the passphrase from file descriptor n. Only the first
line will be read from file descriptor n. If you use 0 for n,
the passphrase will be read from STDIN. This can only be used
if only one passphrase is supplied.


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


--passphrase string
Use string as the passphrase. This can only be used if only
one passphrase is supplied. Obviously, this is of very
questionable security on a multi-user system. Don't use this
option if you can avoid it.


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


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


--allow-non-selfsigned-uid

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


--allow-freeform-uid
Disable all checks on the form of the user ID while generating
a new one. This option should only be used in very special
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 known-weak digest algorithms are normally
rejected with an ``invalid digest algorithm'' message. This
option allows the verification of signatures made with such
weak algorithms. MD5 is the only digest algorithm considered
weak by default. See also --weak-digest to reject other
digest algorithms.


--weak-digest name
Treat the specified digest algorithm as weak. Signatures made
over weak digests algorithms are normally rejected. This
option can be supplied multiple times if multiple algorithms
should be considered weak. See also --allow-weak-digest-algos
to disable rejection of weak digests. MD5 is always
considered weak, and does not need to be listed explicitly.


--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.
DON'T USE IT UNLESS YOU ARE REALLY FORCED TO DO SO.


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


--ask-sig-expire

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


--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

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


--show-photos

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


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


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


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


--show-notation

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


--show-policy-url

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

EXAMPLES

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


gpg --clearsign file
make a clear text signature


gpg -sb file
make a detached signature


gpg -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

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


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

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

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

234567C4
0F34E556E
01347A56A
0xAB123456

234AABBCC34567C4
0F323456784E56EAB
01AB3FED1347A5612
0x234AABBCC34567C4


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

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

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

1234343434343434C434343434343434
123434343434343C3434343434343734349A3434
0E12343434343434343434EAB3484343434343434
0xE12343434343434343434EAB3484343434343434


gpgsm also accepts colons between each pair of hexadecimal digits
because this is the de-facto standard on how to present X.509
fingerprints. gpg also allows the use of the space separated SHA-1
fingerprint as printed by the key listing commands.


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

=Heinrich Heine <heinrichh@uni-duesseldorf.de>


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

<heinrichh@uni-duesseldorf.de>


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

+Heinrich Heine duesseldorf


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

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


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

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


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

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


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

&D75F22C3F86E355877348498CDC92BD21010A480


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

Heine
*Heine


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

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

FILES

There are a few configuration files to control certain aspects of
gpg'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 gpg on
startup. It may contain any valid long option; the leading
two dashes may not be entered and the option may not be
abbreviated. This default name may be changed on the command
line (see: [gpg-option --options]). You should backup this
file.


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

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


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


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


~/.gnupg/pubring.kbx

~/.gnupg/pubring.kbx.lock
A public keyring and its lock file used by GnuPG versions >=
2. It is ignored by GnuPG 1.x


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


~/.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.


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


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


Operation is further controlled by a few environment variables:


HOME Used to locate the default home directory.


GNUPGHOME
If set directory used instead of "~/.gnupg".


GPG_AGENT_INFO
Used to locate the gpg-agent. This is only honored when
--use-agent is set.

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


PINENTRY_USER_DATA
This value is passed via gpg-agent to pinentry. It is useful
to convey extra information to a custom pinentry.


COLUMNS

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


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

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

BUGS

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

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

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

SEE ALSO

gpgv(1),

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

info gnupg

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

GnuPG 1.4.23 2023-03-03 GPG(1)