gpg(1) - Man pages

GPG(1) GNU Privacy Guard 2.4 GPG(1)

NAME
gpg - OpenPGP encryption and signing tool

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

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

There are two main versions of GnuPG: GnuPG 1.x and GnuPG 2.x. GnuPG
2.x supports modern encryption algorithms and thus should be preferred
over GnuPG 1.x. You only need to use GnuPG 1.x if your platform doesn't
support GnuPG 2.x, or you need support for some features that GnuPG 2.x
has deprecated, e.g., decrypting data created with PGP-2 keys.

If you are looking for version 1 of GnuPG, you may find that version in-
stalled under the name gpg1.

RETURN VALUE
The program returns 0 if there are no severe errors, 1 if at least a
signature was bad, and other error codes for fatal errors.

Note that signature verification requires exact knowledge of what has
been signed and by whom it has been signed. Using only the return code
is thus not an appropriate way to verify a signature by a script. Ei-
ther make proper use or the status codes or use the gpgv tool which has
been designed to make signature verification easy for scripts.

WARNINGS
Use a good password for your user account and make sure that all secu-
rity issues are always fixed on your machine. Also employ diligent
physical protection to your machine. Consider to use a good passphrase
as a last resort protection to your secret key in the case your machine
gets stolen. It is important that your secret key is never leaked. Us-
ing an easy to carry around token or smartcard with the secret key is
often a advisable.

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

For scripted or other unattended use of gpg make sure to use the ma-
chine-parseable interface and not the default interface which is in-
tended for direct use by humans. The machine-parseable interface pro-
vides a stable and well documented API independent of the locale or fu-
ture changes of gpg. To enable this interface use the options
--with-colons and --status-fd. For certain operations the option --com-
mand-fd may come handy too. See this man page and the file ‘DETAILS’
for the specification of the interface. Note that the GnuPG ``info''
pages as well as the PDF version of the GnuPG manual features a chapter
on unattended use of GnuPG. As an alternative the library GPGME can be
used as a high-level abstraction on top of that interface.

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

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

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

COMMANDS
Commands are not distinguished from options except for the fact that
only one command is allowed. Generally speaking, irrelevant options are
silently ignored, and may not be checked for correctness.

gpg may be run with no commands. In this case it will print a warning
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, etc.).

If you run into any problems, please add the option --verbose to the in-
vocation to see more diagnostics.

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 arbitrarily abbreviate this com-
mand (though you can use its short form -h).

--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 Sign a message. This command may be combined with --encrypt (to
sign and encrypt a message), --symmetric (to sign and symmetri-
cally encrypt a message), or both --encrypt and --symmetric (to
sign and encrypt a message that can be decrypted using a secret
key or a passphrase). The signing key is chosen by default or
can be set explicitly using the --local-user and --default-key
options.

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

--detach-sign
-b Make a detached signature.

--encrypt
-e Encrypt data to one or more public keys. This command may be com-
bined with --sign (to sign and encrypt a message), --symmetric
(to encrypt a message that can be decrypted using a secret key or
a passphrase), or --sign and --symmetric together (for a signed
message that can be decrypted using a secret key or a
passphrase). --recipient and related options specify which pub-
lic keys to use for encryption.

--symmetric
-c Encrypt with a symmetric cipher using a passphrase. The default
symmetric cipher used is AES-128, but may be chosen with the
--cipher-algo option. This command may be combined with --sign
(for a signed and symmetrically encrypted message), --encrypt
(for a message that may be decrypted via a secret key or a
passphrase), or --sign and --encrypt together (for a signed mes-
sage that may be decrypted via a secret key or a passphrase).
gpg caches the passphrase used for symmetric encryption so that a
decrypt operation may not require that the user needs to enter
the passphrase. The option --no-symkey-cache can be used to dis-
able this feature.

--store
Store only (make a simple 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 that 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 one argument is given, the
specified file is expected to include a complete signature.

With more than one argument, the first argument should specify a
file with a detached signature and the remaining files should
contain the signed data. To read the signed data from STDIN, use
‘-’ as the second filename. For security reasons, a detached
signature will not read the signed material from STDIN if not ex-
plicitly specified.

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; you should always specify the data file ex-
plicitly.

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 the header lines directly
following 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.

Note: With option --batch he verification of signatures stops at
the first bad signature. This is a safe default for unattended
processing but sometimes a status for all signatures is needed.
To override this early bailout use the option --proc-all-sigs.

Note: To check whether a file was signed by a certain key the op-
tion --assert-signer can be used. As an alternative the gpgv
tool can be used. gpgv is designed to compare signed data
against a list of trusted keys and returns with success only for
a good signature. It has its own manual page.

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

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

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

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

--list-keys
-k
--list-public-keys
List the specified keys. If no keys are specified, then all keys
from the configured public keyrings are listed.

Never use the output of this command in scripts or other pro-
grams. The output is intended only for humans and its format is
likely to change. The --with-colons option emits the output in a
stable, machine-parseable format, which is intended for use by
scripts and other programs.

--list-secret-keys
-K List the specified secret keys. If no keys are specified, then
all known secret keys are listed. A # after the initial tags sec
or ssb means that the secret key or subkey is currently not us-
able. We also say that this key has been taken offline (for ex-
ample, a primary key can be taken offline by exporting the key
using the command --export-secret-subkeys). A > after these tags
indicate that the key is stored on a smartcard. See also
--list-keys.

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

The status of the verification is indicated by a flag directly
following the "sig" tag (and thus before the flags described be-
low. 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). Signatures where the public key is not available are
not listed; to see their keyids the command --list-sigs can be
used.

For each signature listed, there are several flags in between the
signature status flag and keyid. These flags give additional in-
formation about each key 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 con-
tains a notation (see --cert-notation), "X" for an eXpired signa-
ture (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").

--locate-keys
--locate-external-keys
Locate the keys given as arguments. This command basically uses
the same algorithm as used when locating keys for encryption and
may thus be used to see what keys gpg might use. In particular
external methods as defined by --auto-key-locate are used to lo-
cate a key if the arguments comain valid mail addresses. Only
public keys are listed.

The variant --locate-external-keys does not consider a locally
existing key and can thus be used to force the refresh of a key
via the defined external methods. If a fingerprint is given and
and the methods defined by --auto-key-locate define LDAP servers,
the key is fetched from these resources; defined non-LDAP key-
servers are skipped.

--show-keys
This commands takes OpenPGP keys as input and prints information
about them in the same way the command --list-keys does for lo-
cally stored key. In addition the list options show-unus-
able-uids, show-unusable-subkeys, show-notations and show-pol-
icy-urls are also enabled. As usual for automated processing,
this command should be combined with the option --with-colons.

--fingerprint
List all keys (or the specified ones) along with their finger-
prints. This is the same output as --list-keys but with the addi-
tional output of a line with the fingerprint. May also be com-
bined with --check-signatures. If this command is given twice,
the fingerprints of all secondary keys are listed too. This com-
mand also forces pretty printing of fingerprints if the keyid
format has been set to "none".

--list-packets
List only the sequence of packets. This command is only useful
for debugging. When used with option --verbose the actual MPI
values are dumped and not only their lengths. Note that the out-
put of this command may change with new releases.

--edit-card
--card-edit
Present a menu to work with a smartcard. The subcommand "help"
provides an overview on available commands. For a detailed de-
scription, please see the Card HOWTO at https://gnupg.org/docu-
mentation/howtos.html#GnuPG-cardHOWTO . Please note that the
command "openpgp" can be used to switch to the OpenPGP applica-
tion of cards which by default are presenting another application
(e.g. PIV).

--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 --edit-card command.

--delete-keys name
Remove key from the public keyring. In batch mode either --yes is
required or the key must be specified by fingerprint. This is a
safeguard against accidental deletion of multiple keys. If the
exclamation mark syntax is used with the fingerprint of a subkey
only that subkey is deleted; if the exclamation mark is used with
the fingerprint of the primary key the entire public key is
deleted.

--delete-secret-keys name
Remove key from the secret keyring. In batch mode the key must be
specified by fingerprint. The option --yes can be used to advise
gpg-agent not to request a confirmation. This extra pre-caution
is done because gpg can't be sure that the secret key (as con-
trolled by gpg-agent) is only used for the given OpenPGP public
key. If the exclamation mark syntax is used with the fingerprint
of a subkey only the secret part of that subkey is deleted; if
the exclamation mark is used with the fingerprint of the primary
key only the secret part of the primary key is deleted.

--delete-secret-and-public-key name
Same as --delete-key, but if a secret key exists, it will be re-
moved first. In batch mode the key must be specified by finger-
print. The option --yes can be used to advise gpg-agent not to
request a confirmation.

--export
Either export all keys from all keyrings (default keyring 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 to-
gether with --armor to mail those keys.

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

Take care: Keyservers are by design write only systems and thus
it is not possible to ever delete keys once they have been send
to a keyserver.

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

The second form of the command has the special property to render
the secret part of the primary key useless; this is a GNU exten-
sion to OpenPGP and other implementations can not be expected to
successfully import such a key. Its intended use is in generat-
ing a full key with an additional signing subkey on a dedicated
machine. This command then exports the key without the primary
key to the main machine.

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

--export-ssh-key
This command is used to export a key in the OpenSSH public key
format. It requires the specification of one key by the usual
means and exports the latest valid subkey which has an authenti-
cation capability to STDOUT or to the file given with option
--output. That output can directly be added to ssh's ‘autho-
rized_key’ file.

By specifying the key to export using a key ID or a fingerprint
suffixed with an exclamation mark (!), a specific subkey or the
primary key can be exported. This does not even require that the
key has the authentication capability flag set.

--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 op-
tion which does not insert new keys but does only the merging of
new signatures, user-IDs and subkeys.

--receive-keys keyIDs
--recv-keys keyIDs
Import the keys with the given keyIDs from a 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.

--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. Note that keyservers search for names in a different
and simpler way than gpg does. The best choice is to use a mail
address. Due to data privacy reasons keyservers may even not
even allow searching by user id or mail address and thus may only
return results when being used with the --recv-key command to
search by key fingerprint or keyid.

--fetch-keys URIs
Retrieve keys located at the specified URIs. Note that different
installations of GnuPG may support different protocols (HTTP,
FTP, LDAP, etc.). When using HTTPS the system provided root cer-
tificates are used by this command.

--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-cre-
ated 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 "*" for algo) di-
gests for all available algorithms are printed.

--gen-random 0|1|2|16|30 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. The special level 16 uses a quality level of 1 and out-
puts an endless stream of hex-encoded octets. The special level
30 outputs random as 30 zBase-32 characters.

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

--enarmor
--dearmor
Pack or unpack an arbitrary input into/from an OpenPGP ASCII ar-
mor. This is a GnuPG extension to OpenPGP and in general not
very useful. The --dearmor command can also be used to dearmor
PEM armors.

--unwrap
This option modifies the command --decrypt to output the original
message with the encryption layer removed. Thus the output will
be an OpenPGP data structure which often means a signed OpenPGP
message. Note that this option may or may not remove a compres-
sion layer which is often found beneath the encryption layer.

--tofu-policy {auto|good|unknown|bad|ask} keys
Set the TOFU policy for all the bindings associated with the
specified keys. For more information about the meaning of the
policies, see: [trust-model-tofu]. The keys may be specified ei-
ther by their fingerprint (preferred) or their keyid.

How to manage your keys

This section explains the main commands for key management.

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

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

If algo or usage are given, only the primary key is created and
no prompts are shown. To specify an expiration date but still
create a primary and subkey use ``default'' or ``future-default''
for algo and ``default'' for usage. For a description of these
optional arguments see the command --quick-add-key. The usage
accepts also the value ``cert'' which can be used to create a
certification only primary key; the default is to a create certi-
fication and signing key.

The expire argument can be used to specify an expiration date for
the key. Several formats are supported; commonly the ISO formats
``YYYY-MM-DD'' or ``YYYYMMDDThhmmss'' are used. To make the key
expire in N seconds, N days, N weeks, N months, or N years use
``seconds=N'', ``Nd'', ``Nw'', ``Nm'', or ``Ny'' respectively.
Not specifying a value, or using ``-'' results in a key expiring
in a reasonable default interval. The values ``never'', ``none''
can be used for no expiration date.

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

To create an OpenPGP key from the keys available on the currently
inserted smartcard, the special string ``card'' can be used for
algo. If the card features an encryption and a signing key, gpg
will figure them out and creates an OpenPGP key consisting of the
usual primary key and one subkey. This works only with certain
smartcards. Note that the interactive --full-gen-key command al-
lows one to do the same but with greater flexibility in the se-
lection of the smartcard keys.

Note that it is possible to create a primary key and a subkey us-
ing non-default algorithms by using ``default'' and changing the
default parameters using the option --default-new-key-algo.

--quick-set-expire fpr expire [*|subfprs]
With two arguments given, directly set the expiration time of the
primary key identified by fpr to expire. To remove the expira-
tion time 0 can be used. With three arguments and the third
given as an asterisk, the expiration time of all non-revoked and
not yet expired subkeys are set to expire. With more than two
arguments and a list of fingerprints given for subfprs, all non-
revoked subkeys matching these fingerprints are set to expire.

--quick-add-key fpr [algo [usage [expire]]]
Directly add a subkey to the key identified by the fingerprint
fpr. Without the optional arguments an encryption subkey is
added. If any of the arguments are given a more specific subkey
is added.

algo may be any of the supported algorithms or curve names given
in the format as used by key listings. To use the default algo-
rithm the string ``default'' or ``-'' can be used. Supported al-
gorithms are ``rsa'', ``dsa'', ``elg'', ``ed25519'', ``cv25519'',
and other ECC curves. For example the string ``rsa'' adds an RSA
key with the default key length; a string ``rsa4096'' requests
that the key length is 4096 bits. The string ``future-default''
is an alias for the algorithm which will likely be used as de-
fault algorithm in future versions of gpg. To list the supported
ECC curves the command gpg --with-colons --list-config curve can
be used.

Depending on the given algo the subkey may either be an encryp-
tion subkey or a signing subkey. If an algorithm is capable of
signing and encryption and such a subkey is desired, a usage
string must be given. This string is either ``default'' or ``-''
to keep the default or a comma delimited list (or space delimited
list) of keywords: ``sign'' for a signing subkey, ``auth'' for an
authentication subkey, and ``encr'' for an encryption subkey
(``encrypt'' can be used as alias for ``encr''). The valid com-
binations depend on the algorithm.

--quick-add-adsk fpr adskfpr
Directly add an Additional Decryption Subkey to the key identi-
fied by the fingerprint fpr. adskfpr is the fingerprint of an-
other key's encryption subkey. A subkey is commonly used here
because by default a primary key has no encryption capability.
Use the option --with-subkey-fingerprint with a list command to
display the subkey fingerprints. If the string "default" is used
for adskfpr all missing ADSKs configured with --de-
fault-new-key-adsk are added.

--generate-key
--gen-key
Generate a new key pair using the current default parameters.
This is the standard command to create a new key. In addition to
the key a revocation certificate is created and stored in the
‘openpgp-revocs.d’ directory below the GnuPG home directory.

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

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

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

This command merely creates the revocation certificate so that it
can be used to revoke the key if that is ever needed. To actu-
ally revoke a key the created revocation certificate needs to be
merged with the key to revoke. This is done by importing the re-
vocation certificate using the --import command. Then the re-
voked key needs to be published, which is best done by sending
the key to a keyserver (command --send-key) and by exporting
(--export) it to a file which is then send to frequent communica-
tion partners.

--generate-designated-revocation name
--desig-revoke name
Generate a designated revocation certificate for a key. This al-
lows 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 com-
mand 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 or key ID 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-ex-
portable and will therefore never be used by others. This
may be used to make keys valid only in the local environ-
ment.

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

tsign Make a trust signature. This is a signature that combines
the notions of certification (like a regular signature),
and trust (like the "trust" command). It is generally use-
ful in distinct communities or groups to implement the
concept of a Trusted Introducer. For more information
please read the sections ``Trust Signature'' and ``Regular
Expression'' in RFC-4880.

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

If the option --only-sign-text-ids is specified, then any non-text based
user ids (e.g., photo IDs) will not be selected for signing.

delsig Delete a signature. Note that it is not possible to re-
tract 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. With the
extra option selfsig only self-signatures are shown.

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 dia-
log box (PGP).

showphoto
Display the selected photographic user ID.

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

revuid Revoke a user ID or photographic user ID.

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

showpref
More verbose preferences listing for the selected user ID.
This shows the preferences in effect by including the im-
plied preferences of 3DES (cipher), SHA-1 (digest), and
Uncompressed (compression) if they are not already in-
cluded 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 argu-
ments sets the preference list to the default (either
built-in or set via --default-preference-list), and call-
ing setpref with "none" as the argument sets an empty
preference list. Use gpg --version to get a list of avail-
able algorithms. Note that while you can change the pref-
erences on an attribute user ID (aka "photo ID"), GnuPG
does not select keys via attribute user IDs so these pref-
erences will not be used by GnuPG. Note that an unat-
tended version of this command is available as --quick-up-
date-pref.

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 re-
cipient), and so the remote OpenPGP application being used
to send to you may or may not follow your exact chosen or-
der 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 trans-
ferred to the card. A sub menu allows you to select on
what card to store the key. Note that it is not possible
to get that key back from the card - if the card gets bro-
ken 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 initial-
ization) 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.

keytotpm
Transfer the selected secret subkey (or the primary key if
no subkey has been selected) to TPM form. The secret key
in the keyring will be replaced by the TPM representation
of that key, which can only be read by the particular TPM
that created it (so the keyfile now becomes locked to the
laptop containing the TPM). Only certain key types may be
transferred to the TPM (all TPM 2.0 systems are mandated
to have the rsa2048 and nistp256 algorithms but newer TPMs
may have more). Note that the key itself is not trans-
ferred into the TPM, merely encrypted by the TPM in-place,
so if the keyfile is deleted, the key will be lost. Once
transferred to TPM representation, the key file can never
be converted back to non-TPM form and the key will die
when the TPM does, so you should first have a backup on
secure offline storage of the actual secret key file be-
fore conversion. It is essential to use the physical sys-
tem TPM that you have rw permission on the TPM resource
manager device (/dev/tpmrm0). Usually this means you must
be a member of the tss group.

delkey Remove a subkey (secondary key). Note that it is not pos-
sible to retract a subkey, once it has been send to the
public (i.e. to a keyserver). In that case you better use
revkey. Also note that this only deletes the public part
of a key.

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 pri-
mary 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 op-
tional argument: "sensitive". If a designated revoker is
marked as sensitive, it will not be exported by default
(see export-options).

addadsk
Add an Additional Decryption Subkey. The user is asked to
enter the fingerprint of another encryption subkey. Note
that the exact fingerprint of another key's encryption
subkey needs to be entered. This is because commonly the
primary key has no encryption capability. Use the option
--with-subkey-fingerprint with a list command to display
the subkey fingerprints.

passwd Change the passphrase of the secret key.

toggle This is dummy command which exists only for backward com-
patibility.

clean Compact (by removing all signatures except the selfsig)
any user ID that is no longer usable (e.g. revoked, or ex-
pired). 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 signa-
tures from each user ID except for the most recent self-
signature.

change-usage
Change the usage flags (capabilities) of the primary key
or of subkeys. These usage flags (e.g. Certify, Sign, Au-
thenticate, Encrypt) are set during key creation. Some-
times it is useful to have the opportunity to change them
(for example to add Authenticate) after they have been
created. Please take care when doing this; the allowed
usage flags depend on the key algorithm.

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

save Save all changes to the keyring and quit.

quit Quit the program without updating the keyring.

The listing shows you the key with its secondary keys and all
user IDs. The primary user ID is indicated by a dot, and se-
lected keys or user IDs are indicated by an asterisk. The trust
value is displayed with the primary key: "trust" is the assigned
owner trust and "validity" is the calculated validity of the key.
Validity values are also displayed for all user IDs. For possi-
ble values of trust, see: [trust-values].

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

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

--quick-sign-key fpr [names]
--quick-lsign-key fpr [names]
Directly sign a key from the passphrase without any further user
interaction. The fpr must be the verified primary fingerprint of
a key in the local keyring. If no names are given, all useful
user ids are signed; with given [names] only useful user ids
matching one of these names are signed. By default, or if a name
is prefixed with a '*', a case insensitive substring match is
used. If a name is prefixed with a '=' a case sensitive exact
match is done.

The command --quick-lsign-key marks the signatures as non-ex-
portable. If such a non-exportable signature already exists the
--quick-sign-key turns it into a exportable signature. If you
need to update an existing signature, for example to add or
change notation data, you need to use the option
--force-sign-key.

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

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

--quick-revoke-uid user-id user-id-to-revoke
This command revokes a user ID on an existing key. It cannot be
used to revoke the last user ID on key (some non-revoked user ID
must remain), with revocation reason ``User ID is no longer
valid''. If you want to specify a different revocation reason,
or to supply supplementary revocation text, you should use the
interactive sub-command revuid of --edit-key.

--quick-revoke-sig fpr signing-fpr [names]
This command revokes the key signatures made by signing-fpr from
the key specified by the fingerprint fpr. With names given only
the signatures on user ids of the key matching any of the given
names are affected (see --quick-sign-key). If a revocation al-
ready exists a notice is printed instead of creating a new revo-
cation; no error is returned in this case. Note that key signa-
ture revocations may be superseded by a newer key signature and
in turn again revoked.

--quick-set-primary-uid user-id primary-user-id
This command sets or updates the primary user ID flag on an ex-
isting key. user-id specifies the key and primary-user-id the
user ID which shall be flagged as the primary user ID. The pri-
mary user ID flag is removed from all other user ids and the
timestamp of all affected self-signatures is set one second
ahead.

--quick-update-pref user-id
This command updates the preference list of the key to the cur-
rent default value (either built-in or set via --default-prefer-
ence-list). This is the unattended version of using "setpref" in
the --key-edit menu without giving a list. Note that you can
show the preferences in a key listing by using --list-options
show-pref or --list-options show-pref-verbose. You should also
re-distribute updated keys to your peers.

--quick-set-ownertrust user-id value
This command sets the ownertrust of a key and can also be used to
set the disable flag of a key. This is the unattended version of
using "trust", "disable", or "enable" in the --key-edit menu.

--change-passphrase user-id
--passwd user-id
Change the passphrase of the secret key belonging to the certifi-
cate specified as user-id. This is a shortcut for the sub-com-
mand passwd of the --edit-key menu. When using together with the
option --dry-run this will not actually change the passphrase but
check that the current passphrase is correct.

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 charac-
ter 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 en-
countered, you can explicitly stop parsing by using the special option
--.

How to change the configuration

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

--default-key name
Use name as the default key to sign with. It is suggested to use
a fingerprint or at least a long keyID for name. 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.
This option may be given multiple times. In this case, the last
key for which a secret key is available is used. If there is no
secret key available for any of the specified values, GnuPG will
not emit an error message but continue as if this option wasn't
given.

--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 and
it is suggested to use a fingerprint for name.

--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 --de-
fault-key.

--no-default-recipient
Reset --default-recipient and --default-recipient-self. Should
not be used in an option file.

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

--no-verbose
Reset verbose level to 0. Should not be used in an option file.

-q, --quiet
Try to be as quiet as possible. Should not be used in an option
file.

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

It is highly recommended to use this option along with the op-
tions --status-fd and --with-colons for any unattended use of
gpg. Should not be used in an option file.

--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. Should not be used in an option
file.

--no Assume "no" on most questions. Should not be used in an option
file.

--proc-all-sigs
This option overrides the behaviour of the --batch option to stop
signature verification at the first bad signatures.

--list-filter {select=expr}
A list filter can be used to output only certain keys during key
listing commands. For the available property names, see the de-
scription of --import-filter.

--list-options parameters
This is a space or comma delimited string that gives options used
when listing keys and signatures (that is, --list-keys,
--check-signatures, --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, --check-signatures, --list-pub-
lic-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 stan-
dard 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 yes.

show-ownertrust
Show the ownertrust value for keys also in the standard
key listing. Defaults to no.

show-policy-urls
Show policy URLs in the --check-signatures listings. De-
faults to no.

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

show-keyserver-urls
Show any preferred keyserver URL in the --check-signatures
listings. Defaults to no.

show-uid-validity
Display the calculated validity of user IDs during key
listings. Defaults to yes.

show-unusable-uids
Show revoked and expired user IDs in key listings. De-
faults to no.

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

show-unusable-sigs
Show key signature made using weak or unsupported algo-
rithms.

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
--check-signatures listings. Defaults to no.

show-sig-subpackets
Include signature subpackets in the key listing. This op-
tion 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 --check-signatures.

show-only-fpr-mbox
For each user-id which has a valid mail address print only
the fingerprint followed by the mail address.

sort-sigs
With --list-sigs and --check-sigs sort the signatures by
keyID and creation time to make it easier to view the his-
tory of these signatures. The self-signature is also
listed before other signatures. Defaults to yes. This op-
tion has no effect in -with-colons mode.

--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 yes.

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

show-keyserver-urls
Show any preferred keyserver URL in the signature being
verified. Defaults to yes.

show-uid-validity
Display the calculated validity of the user IDs on the key
that issued the signature. Defaults to yes.

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

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

--enable-large-rsa
--disable-large-rsa
Enable the creation of RSA secret keys as large as 8192 bit.
Note: 8192 bit is more than is generally recommended. These
large keys don't significantly improve security, but they are
more expensive to use, and their signatures and certifications
are larger. This option is only available if the binary was
build with large-secmem support.

--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 gen-
eration 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 im-
age (e.g. "image/jpeg"), "%v" for the single-character calculated
validity of the image being viewed (e.g. "f"), "%V" for the cal-
culated 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.

On Unix the default viewer is xloadimage -fork -quiet -title
'KeyID 0x%k' STDIN with a fallback to display -title 'KeyID 0x%k'
%i and finally to xdg-open %i. On Windows !ShellExecute 400 %i
is used; here the command is a meta command to use that API call
followed by a wait time in milliseconds which is used to give the
viewer time to read the temporary image file before gpg deletes
it again. Note that if your image viewer program is not secure,
then executing it from gpg does not make it secure.

--exec-path string
Sets a list of directories to search for photo viewers If not
provided photo viewers use the PATH environment variable.

--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" unless --homedir or $GNUPGHOME
is 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.

If the option --no-keyring has been used no keyrings will be used
at all.

Note that if the option use-keyboxd is enabled in ‘common.conf’,
no keyrings are used at all and keys are all maintained by the
keyboxd process in its own database.

--primary-keyring file
This is a varian of --keyring and designates file as the primary
public keyring. This means that newly imported keys (via --import
or keyserver --recv-from) will go to this keyring.

--secret-keyring file
This is an obsolete option and ignored. All secret keys are
stored in the ‘private-keys-v1.d’ directory below the GnuPG home
directory.

--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 rec-
ognized 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 en-
try 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 con-
sidered, all other ways to set a home directory are ignored.

--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 en-
coding. 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. This option should not be used on Windows.
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 (RFC-1489).

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 UTF-8 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. This option should not be used in an option
file.

This option has no effect on Windows. There the internal used
UTF-8 encoding is translated for console input and output. The
command line arguments are expected as Unicode and translated to
UTF-8. Thus when calling this program from another, make sure to
use the Unicode version of CreateProcess.

--options file
Read options from file and do not try to read them from the de-
fault 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
--no-compress
Set compression level to n for the ZIP and ZLIB compression algo-
rithms. 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.

Option -z sets both. A value of 0 for n disables compression. A
value of -1 forces compression using the default level. Option
--no-compress is identical to -z0.

Except for the --store command compression is always used unless
gpg detects that the input is already compressed. To inhibit the
use of compression use -z0 or --no-compress; to force compression
use -z-1 or option z with another compression level than the de-
fault as indicated by -1. Note that this overriding of the de-
fault deection works only with z and not with the long variant of
this option.

--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 informa-
tion 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 ver-
ified 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 or fingerprint
Assume that the specified key (which should be given as finger-
print) is as trustworthy as one of your own secret keys. This op-
tion 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. If the given key is
not locally available but an LDAP keyserver is configured the
missing key is imported from that server. The value "none" is
explicitly allowed to distinguish between the use of any trusted-
key option and no use of this option at all (e.g. due to the
--no-options option).

--add-desig-revoker [sensitive:]fingerprint
Add the key specified by fingerprint as a designated revoker to
newly created keys. If the fingerprint is prefixed with the key-
word ``sensitive:'' that info is normally not exported with the
key. This option may be given several times to add more than one
designated revoker. If the keyword ``clear'' is used instead of
a fingerprint, all previously fiven fingerprints are discarded.
Designated revokers are marked on the key as non-revocable. Note
that a designated revoker specified using a parameter file will
also be added to the key.

--default-new-key-adsk fingerprint
Add the subkey specified by fingerprint as an Additional Decryp-
tion Subkey (ADSK) to newly created keys. This option may be
given several time to add more than one ADSK. It is also possi-
ble to give several fingerprints delimited by space or comma as
value to this option. If the keyword ``clear'' is used instead
of a fingerprint, all previously specified fingerprints are dis-
carded (useful to override options given in a config file). The
fingerprint is expected to specify a subkey and it does not need
an exclamation mark as suffix; it must be given in cmpact format
(40 or 64 hex-digits without any spaces).

--trust-model {pgp|classic|tofu|tofu+pgp|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.

tofu

TOFU stands for Trust On First Use. In this experimental
trust model, the first time a key is seen, it is memo-
rized. If later another key with a user id with the same
email address is seen, both keys are marked as suspect.
In that case, the next time either is used, a warning is
displayed describing the conflict, why it might have oc-
curred (either the user generated a new key and failed to
cross sign the old and new keys, the key is forgery, or a
man-in-the-middle attack is being attempted), and the user
is prompted to manually confirm the validity of the key in
question.

Because a potential attacker is able to control the email
address and thereby circumvent the conflict detection al-
gorithm by using an email address that is similar in ap-
pearance to a trusted email address, whenever a message is
verified, statistics about the number of messages signed
with the key are shown. In this way, a user can easily
identify attacks using fake keys for regular correspon-
dents.

When compared with the Web of Trust, TOFU offers signifi-
cantly weaker security guarantees. In particular, TOFU
only helps ensure consistency (that is, that the binding
between a key and email address doesn't change). A major
advantage of TOFU is that it requires little maintenance
to use correctly. To use the web of trust properly, you
need to actively sign keys and mark users as trusted in-
troducers. This is a time-consuming process and anecdotal
evidence suggests that even security-conscious users
rarely take the time to do this thoroughly and instead
rely on an ad-hoc TOFU process.

In the TOFU model, policies are associated with bindings
between keys and email addresses (which are extracted from
user ids and normalized). There are five policies, which
can be set manually using the --tofu-policy option. The
default policy can be set using the --tofu-default-policy
option.

The TOFU policies are: auto, good, unknown, bad and ask.
The auto policy is used by default (unless overridden by
--tofu-default-policy) and marks a binding as marginally
trusted. The good, unknown and bad policies mark a bind-
ing as fully trusted, as having unknown trust or as having
trust never, respectively. The unknown policy is useful
for just using TOFU to detect conflicts, but to never as-
sign positive trust to a binding. The final policy, ask
prompts the user to indicate the binding's trust. If
batch mode is enabled (or input is inappropriate in the
context), then the user is not prompted and the undefined
trust level is returned.

tofu+pgp
This experimental trust model combines TOFU with the Web
of Trust. This is done by computing the trust level for
each model and then taking the maximum trust level where
the trust levels are ordered as follows: unknown < unde-
fined < marginal < fully < ultimate < expired < never.

By setting --tofu-default-policy=unknown, this model can
be used to implement the web of trust with TOFU's conflict
detection algorithm, but without its assignment of posi-
tive trust values, which some security-conscious users
don't like.

direct Key validity is set directly by the user and not calcu-
lated via the Web of Trust. This model is solely based on
the key and does not distinguish user IDs. Note that when
changing to another trust model the trust values assigned
to a key are transformed into ownertrust values, which
also indicate how you trust the owner of the key to sign
other keys.

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 al-
low 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. Note that a tofu trust model is
not considered here and must be enabled explicitly.

--always-trust
Identical to --trust-model always.

--assert-signer fpr_or_file
This option checks whether at least one valid signature on a file
has been made with the specified key. The key is either speci-
fied as a fingerprint or a file listing fingerprints. The fin-
gerprint must be given or listed in compact format (no colons or
spaces in between). This option can be given multiple times and
each fingerprint is checked against the signing key as well as
the corresponding primary key. If fpr_or_file specifies a file,
empty lines are ignored as well as all lines starting with a hash
sign. With this option gpg is guaranteed to return with an exit
code of 0 if and only if a signature has been encountered, is
valid, and the key matches one of the fingerprints given by this
option.

--assert-pubkey-algo algolist
During data signature verification this options checks whether
the used public key algorithm matches the algorithms given by al-
golist. This option can be given multiple times to concatenate
more algorithms to the list; the delimiter of the list are either
commas or spaces.

The algorithm names given in the list may either be verbatim
names like "ed25519" with an optional leading single equal sign,
or being prefixed with ">", ">=", "<=", or "<". That prefix op-
erator is applied to the number part of the algorithm name; for
example 2048 in "rsa2048" or 384 in "brainpoolP384r1". If the
the leading non-digits in the name matches, the prefix operator
is used to compare the number part, a trailing suffix is ignored
in this case. For example an algorithm list ">rsa3000, >=brain-
pool384r1, =ed25519" allows RSA signatures with more that 3000
bits, Brainpool curves 384 and 512, and the ed25519 algorithm.

With this option gpg (and also gpgv) is guaranteed to return with
an exit code of 0 if and only if all valid signatures on data are
made using a matching algorithm from the given list.

--auto-key-locate mechanisms
--no-auto-key-locate
GnuPG can automatically locate and retrieve keys as needed using
this option. This happens when encrypting to an email address
(in the "user@example.com" form), and there are no "user@exam-
ple.com" keys on the local keyring. This option takes any number
of the mechanisms listed below, in the order they are to be
tried. Instead of listing the mechanisms as comma delimited ar-
guments, the option may also be given several times to add more
mechanism. The option --no-auto-key-locate or the mechanism
"clear" resets the list. The default is "local,wkd".

cert Locate a key using DNS CERT, as specified in RFC-4398.

dane Locate a key using DANE, as specified in draft-ietf-dane-
openpgpkey-05.txt.

wkd Locate a key using the Web Key Directory protocol.

ldap Locate the key using the configured LDAP servers. This
method is similar to the keyserver mechanism but always
uses only LDAP servers.

ntds Locate the key using the Active Directory (Windows only).
This method also allows one to search by fingerprint using
the command --locate-external-key. Note that this mecha-
nism is actually a shortcut for the mechanism ‘ldap’ using
only "ldap:///" as the keyserver.

keyserver
Locate a key using a keyserver. This method also allows
one to search by fingerprint using the command --lo-
cate-external-key if any of the configured keyservers is
an LDAP server.

keyserver-URL
In addition, a keyserver URL as used in the dirmngr con-
figuration may be used here to query that particular key-
server. This method also allows one to search by finger-
print using the command --locate-external-key if the URL
specifies an LDAP server.

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 be-
fore any of the mechanisms defined by the --auto-key-lo-
cate 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. Note that a nodefault
in mechanisms will also be cleared unless it is given af-
ter the clear.

--auto-key-import
--no-auto-key-import
This is an offline mechanism to get a missing key for signature
verification and for later encryption to this key. If this op-
tion is enabled and a signature includes an embedded key, that
key is used to verify the signature and on verification success
the key is imported. The default is --no-auto-key-import.

On the sender (signing) site the option --include-key-block needs
to be used to put the public part of the signing key as “Key
Block subpacket” into the signature.

--auto-key-retrieve
--no-auto-key-retrieve
These options enable or disable the automatic retrieving of keys
from a keyserver when verifying signatures made by keys that are
not on the local keyring. The default is --no-auto-key-retrieve.

The order of methods tried to lookup the key is:

1. If the option --auto-key-import is set and the signatures in-
cludes an embedded key, that key is used to verify the signature
and on verification success that key is imported.

2. If a preferred keyserver is specified in the signature and the
option honor-keyserver-url is active (which is not the default),
that keyserver is tried. Note that the creator of the signature
uses the option --sig-keyserver-url to specify the preferred key-
server for data signatures.

3. If the signature has the Signer's UID set (e.g. using --sender
while creating the signature) a Web Key Directory (WKD) lookup is
done. This is the default configuration but can be disabled by
removing WKD from the auto-key-locate list or by using the option
--disable-signer-uid.

4. If any keyserver is configured and the Issuer Fingerprint is
part of the signature (since GnuPG 2.1.16), the configured key-
servers are tried.

Note that this option makes a "web bug" like behavior possible.
Keyserver or Web Key Directory 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 ver-
ified the signature.

--keyid-format {none|short|0xshort|long|0xlong}
Select how to display key IDs. "none" does not show the key ID
at all but shows the fingerprint in a separate line. "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
This option is deprecated - please use the --keyserver in ‘dirm-
ngr.conf’ instead.

Use name as your keyserver. This is the server that --re-
ceive-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"/"hkps" for the HTTP
(or compatible) keyservers or "ldap"/"ldaps" for the LDAP key-
servers. Note that your particular installation of GnuPG may
have other keyserver types available as well. Keyserver schemes
are case-insensitive.

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

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

include-revoked
When searching for a key with --search-keys, include keys
that are marked on the keyserver as revoked. Note that not
all keyservers differentiate between revoked and unrevoked
keys, and for such keyservers this option is meaningless.
Note also that most keyservers do not have cryptographic
verification of key revocations, and so turning this op-
tion 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 is an obsolete alias for the option auto-key-re-
trieve. Please do not use it; it will be removed in fu-
ture versions..

honor-keyserver-url
When using --refresh-keys, if the key in question has a
preferred keyserver URL, then use that preferred keyserver
to refresh the key from. In addition, if auto-key-retrieve
is set, and the signature being verified has a preferred
keyserver URL, then use that preferred keyserver to fetch
the key from. Note that this option introduces a "web
bug": The creator of the key can see when the keys is re-
freshed. Thus this option is not enabled by default.

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

only-pubkeys
Do now allow to import secret keys.

timeout
http-proxy=value
verbose
debug
check-cert

ca-cert-file
These options have no more function since GnuPG 2.1. Use
the dirmngr configuration options instead.

The default list of options is: "self-sigs-only, repair-keys, repair-
pks-subkey-bug, export-attributes". However, if the actual used source
is an LDAP server "no-self-sigs-only" is assumed unless "self-sigs-only"
has been explicitly configured.

--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)

--tofu-default-policy {auto|good|unknown|bad|ask}
The default TOFU policy (defaults to auto). For more information
about the meaning of this option, see: [trust-model-tofu].

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

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

--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 in-
ternally. This may be a time consuming process.
--no-auto-check-trustdb disables this option.

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

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

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

--dirmngr-program file
Specify a dirmngr program to be used for keyserver access. The
default value is ‘/usr/bin/dirmngr’.

--disable-dirmngr
Entirely disable the use of the Dirmngr.

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

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

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

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

--exit-on-status-write-error
This option will cause write errors on the status FD to immedi-
ately terminate the process. That should in fact be the default
but it never worked this way and thus we need an option to enable
this, so that the change won't break applications which close
their end of a status fd connected pipe too early. Using this op-
tion 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 appli-
cation does not know about the smartcard support and waits ad in-
finitum for an inserted card.

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

--no-greeting
Suppress the initial copyright message.

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

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

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.

--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 incom-
patible things like generating unusual key types. This also dis-
ables certain warning messages about potentially incompatible ac-
tions. 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-recip-
ient 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 un-
less --default-recipient is given.

--recipient-file file
-f This option is similar to --recipient except that it encrypts to
a key stored in the given file. file must be the name of a file
containing exactly one key. gpg assumes that the key in this
file is fully valid.

--hidden-recipient-file file
-F This option is similar to --hidden-recipient except that it en-
crypts to a key stored in the given file. file must be the name
of a file containing exactly one key. gpg assumes that the key
in this file is fully valid.

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

--hidden-encrypt-to name
Same as --hidden-recipient but this one is intended for use in
the options file and may be used with your own user-id as a hid-
den "encrypt-to-self". It is suggested to use a fingerprint or
at least a long keyID for name. 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=value}
Sets up a named group, which is similar to aliases in email pro-
grams. Any time the group name is a recipient (-r or --recipi-
ent), it will be expanded to the values specified. Multiple
groups with the same name are automatically merged into a single
group.

The values are key IDs or fingerprints, but any key description
is accepted. Note that a value with spaces in it will be treated
as two different values. Note also there is only one level of ex-
pansion --- 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.

--sender mbox
This option has two purposes. mbox must either be a complete
user ID containing a proper mail address or just a plain mail ad-
dress. The option can be given multiple times.

When creating a signature this option tells gpg the signing key's
user id used to make the signature and embeds that user ID into
the created signature (using OpenPGP's ``Signer's User ID'' sub-
packet). If the option is given multiple times a suitable user
ID is picked. However, if the signing key was specified directly
by using a mail address (i.e. not by using a fingerprint or key
ID) this option is used and the mail address is embedded in the
created signature.

When verifying a signature mbox is used to restrict the informa-
tion printed by the TOFU code to matching user IDs. If the op-
tion is used and the signature contains a ``Signer's User ID''
subpacket that information is is also used to restrict the
printed information. Note that GnuPG considers only the mail ad-
dress part of a User ID.

If this option or the said subpacket is available the TRUST lines
as printed by option status-fd correspond to the corresponding
User ID; if no User ID is known the TRUST lines are computed di-
rectly on the key and do not give any information about the User
ID. In the latter case it his highly recommended to scripts and
other frontends to evaluate the VALIDSIG line, retrieve the key
and print all User IDs along with their validity (trust) informa-
tion.

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

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

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

Input and Output

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

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

--output file
-o file
Write output to file. To write to stdout use - as the filename.

--max-output n
This option sets a limit on the number of bytes that will be gen-
erated 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".

--chunk-size n
The AEAD encryption mode encrypts the data in chunks so that a
receiving side can check for transmission errors or tampering at
the end of each chunk and does not need to delay this until all
data has been received. The used chunk size is 2^n byte. The
lowest allowed value for n is 6 (64 byte) and the largest is the
default of 22 which creates chunks not larger than 4 MiB.

--input-size-hint n
This option can be used to tell GPG the size of the input data in
bytes. n must be a positive base-10 number. This option is only
useful if the input is not taken from a file. GPG may use this
hint to optimize its buffer allocation strategy. It is also used
by the --status-fd line ``PROGRESS'' to provide a value for ``to-
tal'' if that is not available by other means.

--key-origin string[,url]
gpg can track the origin of a key. Certain origins are implicitly
known (e.g. keyserver, web key directory) and set. For a stan-
dard import the origin of the keys imported can be set with this
option. To list the possible values use "help" for string. Some
origins can store an optional url argument. That URL can ap-
pended to string after a comma.

--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 be-
ing 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 automat-
ically 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 op-
tion.

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 sub-
key. Defaults to no for regular --import and to yes for
keyserver --receive-keys.

import-show
show-only
Show a listing of the key as imported right before it is
stored. This can be combined with the option --dry-run to
only look at keys; the option show-only is a shortcut for
this combination. The command --show-keys is another
shortcut for this. Note that suffixes like '#' for "sec"
and "sbb" lines may or may not be printed.

import-export
Run the entire import code but instead of storing the key
to the local keyring write it to the output. The export
option export-dane affect the output. This option can for
example be used to remove all invalid parts from a key
without the need to store it.

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" af-
ter import. Defaults to no.

self-sigs-only
Accept only self-signatures while importing a key. All
other key signatures are skipped at an early import stage.
This option can be used with keyserver-options to mitigate
attempts to flood a key with bogus signatures from a key-
server. The drawback is that all other valid key signa-
tures, as required by the Web of Trust are also not im-
ported. Note that when using this option along with im-
port-clean it suppresses the final clean step after merg-
ing the imported key into the existing key.

ignore-attributes
Ignore all attribute user IDs (photo IDs) and their signa-
tures while importing a key.

repair-keys
After import, fix various problems with the keys. For ex-
ample, this reorders signatures, and strips duplicate sig-
natures. Defaults to yes.

bulk-import
When used the keyboxd (option use-keyboxd in ‘com-
mon.conf’) does the import within a single transaction.

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

restore
import-restore
Import in key restore mode. This imports all data which
is usually skipped during import; including all GnuPG spe-
cific data. All other contradicting options are overrid-
den.

--import-filter {name=expr}
--export-filter {name=expr}
These options define an import/export filter which are applied to
the imported/exported keyblock right before it will be
stored/written. name defines the type of filter to use, expr the
expression to evaluate. The option can be used several times
which then appends more expression to the same name.

The available filter types are:

keep-uid
This filter will keep a user id packet and its dependent
packets in the keyblock if the expression evaluates to
true.

drop-subkey
This filter drops the selected subkeys. Currently only
implemented for --export-filter.

drop-sig
This filter drops the selected key signatures on user ids.
Self-signatures are not considered. Currently only imple-
mented for --import-filter.

select This filter is only implemented by --list-filter. All
property names may be used.

For the syntax of the expression see the chapter "FILTER EXPRESSIONS".
The property names for the expressions depend on the actual filter type
and are indicated in the following table. Note that all property names
may also be used by --list-filter.

Property names may be prefix with a scope delimited by a slash. Valid
scopes are "pub" for public and secret primary keys, "sub" for public
and secret subkeys, "uid" for for user-ID packets, and "sig" for signa-
ture packets. Invalid scopes are currently ignored.

The available properties are:

uid A string with the user id. (keep-uid)

mbox The addr-spec part of a user id with mailbox or the empty
string. (keep-uid)

algostr
A string with the key algorithm description. For example
"rsa3072" or "ed25519".

key_algo
A number with the public key algorithm of a key or subkey
packet. (drop-subkey)

key_size
A number with the effective key size of a key or subkey
packet. (drop-subkey)

key_created
key_created_d
The first is the timestamp a public key or subkey packet
was created. The second is the same but given as an ISO
string, e.g. "2016-08-17". (drop-subkey)

key_expires
key_expires_d
The expiration time of a public key or subkey or 0 if it
does not expire. The second is the same but given as an
ISO date string or an empty string e.g. "2038-01-19".

fpr The hexified fingerprint of the current subkey or primary
key. (drop-subkey)

primary
Boolean indicating whether the user id is the primary one.
(keep-uid)

expired
Boolean indicating whether a user id (keep-uid), a key
(drop-subkey), or a signature (drop-sig) expired.

revoked
Boolean indicating whether a user id (keep-uid) or a key
(drop-subkey) has been revoked.

disabled
Boolean indicating whether a primary key is disabled.

secret Boolean indicating whether a key or subkey is a secret
one. (drop-subkey)

usage A string indicating the usage flags for the subkey, from
the sequence ``ecsa?''. For example, a subkey capable of
just signing and authentication would be an exact match
for ``sa''. (drop-subkey)

sig_created
sig_created_d
The first is the timestamp a signature packet was created.
The second is the same but given as an ISO date string,
e.g. "2016-08-17". (drop-sig)

sig_expires
sig_expires_d
The expiration time of a signature packet or 0 if it does
not expire. The second is the same but given as an ISO
date string or an empty string e.g. "2038-01-19".

sig_algo
A number with the public key algorithm of a signature
packet. (drop-sig)

sig_digest_algo
A number with the digest algorithm of a signature packet.
(drop-sig)

origin A string with the key origin or a question mark. For ex-
ample the string ``wkd'' is used if a key originated from
a Web Key Directory lookup.

lastupd
The timestamp the key was last updated from a keyserver or
the Web Key Directory.

url A string with the the URL associated wit the last key
lookup.

--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 be-
ing used. Defaults to no.

export-attributes
Include attribute user IDs (photo IDs) while exporting.
Not including attribute user IDs is useful to export keys
that 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.

backup
export-backup
Export for use as a backup. The exported data includes
all data which is needed to restore the key or keys later
with GnuPG. The format is basically the OpenPGP format
but enhanced with GnuPG specific data. All other contra-
dicting options are overridden.

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 in-
cludes 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 signa-
tures except the most recent self-signature on each user
ID. This option is the same as running the --edit-key com-
mand "minimize" before export except that the local copy
of the key is not modified. Defaults to no.

export-revocs
Export only standalone revocation certificates of the key.
This option does not export revocations of 3rd party cer-
tificate revocations.

export-dane
Instead of outputting the key material output OpenPGP DANE
records suitable to put into DNS zone files. An ORIGIN
line is printed before each record to allow diverting the
records to the corresponding zone file.

mode1003
Enable the use of a new secret key export format. This
format avoids the re-encryption as required with the cur-
rent OpenPGP format and also improves the security of the
secret key if it has been protected with a passphrase.
Note that an unprotected key is exported as-is and thus
not secure; the general rule to convey secret keys in an
OpenPGP encrypted file still applies with this mode. Ver-
sions of GnuPG before 2.4.0 are not able to import such a
secret file.

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

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

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

--with-subkey-fingerprint
If a fingerprint is printed for the primary key, this option
forces printing of the fingerprint for all subkeys. This could
also be achieved by using the --with-fingerprint twice but by us-
ing this option along with keyid-format "none" a compact finger-
print is printed.

--with-v5-fingerprint
In a colon mode listing emit "fp2" lines for version 4 OpenPGP
keys having a v5 style fingerprint of the key.

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

--with-keygrip
Include the keygrip in the key listings. In --with-colons mode
this is implicitly enable for secret keys.

--with-key-origin
Include the locally held information on the origin and last up-
date of a key in a key listing. In --with-colons mode this is
always printed. This data is currently experimental and shall
not be considered part of the stable API.

--with-wkd-hash
Print a Web Key Directory identifier along with each user ID in
key listings. This is an experimental feature and semantics may
change.

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

OpenPGP protocol specific options

--force-ocb
--force-aead
Force the use of AEAD encryption over MDC encryption. AEAD is a
modern and faster way to do authenticated encryption than the old
MDC method. --force-aead is an alias and deprecated. See also
option --chunk-size.

--force-mdc
--disable-mdc
These options are obsolete and have no effect since GnuPG 2.2.8.
The MDC is always used unless the keys indicate that an AEAD al-
gorithm can be used in which case AEAD is used. But note: If the
creation of a legacy non-MDC message is exceptionally required,
the option --rfc2440 allows for this.

--disable-signer-uid
By default the user ID of the signing key is embedded in the data
signature. As of now this is only done if the signing key has
been specified with local-user using a mail address, or with
sender. This information can be helpful for verifier to locate
the key; see option --auto-key-retrieve.

--include-key-block
--no-include-key-block
This option is used to embed the actual signing key into a data
signature. The embedded key is stripped down to a single user id
and includes only the signing subkey used to create the signature
as well as as valid encryption subkeys. All other info is re-
moved from the key to keep it and thus the signature small. This
option is the OpenPGP counterpart to the gpgsm option --in-
clude-certs and allows the recipient of a signed message to reply
encrypted to the sender without using any online directories to
lookup the key. The default is --no-include-key-block. See also
the option --auto-key-import.

--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 over-
ride the algorithm chosen by the recipient key preferences, as
GPG will only select an algorithm that is usable by all recipi-
ents. 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 over-
ride the algorithm chosen by the recipient key preferences, as
GPG will only select an algorithm that is usable by all recipi-
ents. The most highly ranked digest algorithm in this list is
also used when signing without encryption (e.g. --clear-sign 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 recip-
ients. 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 for symmetric encryption with a
passphrase if --personal-cipher-preferences and --cipher-algo are
not given. The default is AES-128.

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

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

--s2k-count n
Specify how many times the passphrases mangling for symmetric en-
cryption 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 near-
est legal value. This option is only meaningful if --s2k-mode is
set to the default of 3.

Compliance options

These options control what GnuPG is compliant to. Only one of these op-
tions may be active at a time. If multiple options are given, the last
one supersedes all the others. 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 now LibrePGP behavior, which
is a different draft protocol that overlaps in some cases with
OpenPGP.

--openpgp
Set all packet, cipher and digest options to OpenPGP compatible
(RFC-9580) behavior. Note that not all of RFC-9580 is imple-
mented by GnuPG. This is the default option, so it is not gener-
ally needed, but it may be useful to override a different compli-
ance option in the gpg.conf file.

--rfc4880
Set all packet, cipher and digest options to strict RFC-4880 be-
havior. RFC-4880 is the legacy version of the OpenPGP standard.
This option implies --allow-old-cipher-algos.

--rfc4880bis
This option is obsolete; it is handled as an alias for --gnupg.

--rfc2440
Set all packet, cipher and digest options to strict RFC-2440 be-
havior. RFC-2440 is a very old version of OpenPGP. Note that by
using this option encryption packets are created in a legacy mode
without MDC protection. This is dangerous and should thus only
be used for experiments. This option implies --allow-old-ci-
pher-algos. See also option --ignore-mdc-error.

--pgp6 This option is obsolete; it is handled as an alias for --pgp7.

--pgp7 Set up all options to be as PGP 7 compliant as possible. This al-
lowed the ciphers IDEA, 3DES, CAST5,AES128, AES192, AES256, and
TWOFISH., the hashes MD5, SHA1 and RIPEMD160, and the compression
algorithms none and ZIP. This option implies --escape-from-lines
and disables --throw-keyids,

--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 --es-
cape-from-lines. All algorithms are allowed except for the
SHA224, SHA384, and SHA512 digests.

--compliance string
This option can be used instead of one of the options above.
Valid values for string are the above option names (without the
double dash) and possibly others as shown when using "help" for
string.

--min-rsa-length n
This option adjusts the compliance mode "de-vs" for stricter key
size requirements. For example, a value of 3000 turns rsa2048
and dsa2048 keys into non-VS-NfD compliant keys.

--require-compliance
To check that data has been encrypted according to the rules of
the current compliance mode, a gpg user needs to evaluate the
status lines. This is allows frontends to handle compliance
check in a more flexible way. However, for scripted use the re-
quired evaluation of the status-line requires quite some effort;
this option can be used instead to make sure that the gpg process
exits with a failure if the compliance rules are not fulfilled.
Note that this option has currently an effect only in "de-vs"
mode.

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 option may be
extended in the future. Currently it only skips the actual de-
cryption pass and therefore enables a fast listing of the encryp-
tion keys.

-i
--interactive
Prompt before overwriting any files.

--compatibility-flags flags
Set compatibility flags to work around problems due to non-com-
pliant keys or data. The flags are given as a comma separated
list of flag names and are OR-ed together. The special flag
"none" clears the list and allows one to start over with an empty
list. To get a list of available flags the sole word "help" can
be used.

--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 spec-
ified and may change with newer releases of this program. They are how-
ever carefully selected to best aid in debugging.

--debug flags
Set debug flags. All flags are or-ed and flags may be given in C
syntax (e.g. 0x0042) or as a comma separated list of flag names.
To get a list of all supported flags the single word "help" can
be used. This option is only useful for debugging and the behav-
ior may change at any time without notice.

--debug-all
Set all useful debugging flags.

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

--debug-set-iobuf-size n
Change the buffer size of the IOBUFs to n kilobyte. Using 0
prints the current size. Note well: This is a maintainer only
option and may thus be changed or removed at any time without no-
tice.

--debug-allow-large-chunks
To facilitate software tests and experiments this option allows
one to specify a limit of up to 4 EiB (--chunk-size 62).

--debug-ignore-expiration
This option tries to override certain key expiration dates. It
is only useful for certain regression tests.

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

If you suffix epoch with an exclamation mark (!), the system time
will appear to be frozen at the specified time.

--full-timestrings
Change the format of printed creation and expiration times from
just the date to the date and time. This is in general not use-
ful and the same information is anyway available in --with-colons
mode. These longer strings are also not well aligned with other
printed data.

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

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

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

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

--log-file file
--logger-file file
Same as --logger-fd, except the logger data is written to file
file. Use ‘socket://’ to log to s socket.

--log-time
Prefix all log output with a timestamp even if no log file is
used.

--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 de-
livered 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 cleartext 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 com-
ment 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 thrice
the micro is added, and given four times an operating system
identification is also emitted. --no-emit-version (default) dis-
ables 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.exam-
ple.com (substituting the appropriate keyname and domain name, of
course). This is to help prevent pollution of the IETF reserved
notation namespace. The --expert flag overrides the '@' check.
value may be any printable string; it will be encoded in UTF-8,
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-nota-
tion 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 fin-
gerprint of the key being signed, "%s" into the key ID of the key
making the signature, "%S" into the long key ID of the key making
the signature, "%g" into the fingerprint of the key 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.

--known-notation name
Adds name to a list of known critical signature notations. The
effect of this is that gpg will not mark a signature with a crit-
ical signature notation of that name as bad. Note that gpg al-
ready knows by default about a few critical signatures notation
names.

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

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

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

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

--set-filename string
Use string as the filename which is stored inside messages. This
overrides the default, which is to use the actual filename of the
file being encrypted. Using the empty string for string effec-
tively removes the filename from the output.

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

--use-embedded-filename
--no-use-embedded-filename
Try to create a file with a name as embedded in the data. This
can be a dangerous option as it enables overwriting files by giv-
ing the sender control on how to store files. Defaults to no.
Note that the option --output overrides this option.

A better approach than using this option is to decrypt to a tem-
porary filename and then rename that file to the embedded file
name after checking that the embedded filename is harmless. When
using the --status-fd option gpg tells the filename as part of
the PLAINTEXT status message. If the filename is important, the
use of gpgtar is another option because gpgtar will never over-
write a file but decrypt the files to a new directory.

Note also that unless a modern version 5 signature is used the
embedded filename is not part of the signed data.

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

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

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

--cert-digest-algo name
Use name as the message digest algorithm used when signing a key.
Running the program with the command --version yields a list of
supported algorithms. Be aware that if you choose an algorithm
that GnuPG supports but other OpenPGP implementations do not,
then some users will not be able to use the key signatures you
make, or quite possibly your entire key. Note also that a public
key algorithm must be compatible with the specified digest algo-
rithm; thus selecting an arbitrary digest algorithm may result in
error messages from lower crypto layers or lead to security
flaws.

--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 coun-
termeasure against traffic analysis. ([Using a little social en-
gineering 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 be-
cause all available secret keys must be tried. --no-throw-keyids
disables this option. This option is essentially the same as us-
ing --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 ar-
mored 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 signa-
ture 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 re-
peated. This is useful for helping memorize a passphrase. De-
faults to 1 repetition; can be set to 0 to disable any passphrase
repetition. Note that a n greater than 1 will pop up the pinen-
try window n+1 times even if a modern pinentry with two entry
fields is used.

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

Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1 the
--pinentry-mode also needs to be set to loopback.

--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 ques-
tionable security if other users can read this file. Don't use
this option if you can avoid it.

Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1 the
--pinentry-mode also needs to be set to loopback.

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

Note that since Version 2.0 this passphrase is only used if the
option --batch has also been given. Since Version 2.1 the
--pinentry-mode also needs to be set to loopback.

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

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

ask Force the use of the Pinentry.

cancel Emulate use of Pinentry's cancel button.

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

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

--no-symkey-cache
Disable the passphrase cache used for symmetrical en- and decryp-
tion. This cache is based on the message specific salt value
(cf. --s2k-mode).

--request-origin origin
Tell gpg to assume that the operation ultimately originated at
origin. Depending on the origin certain restrictions are applied
and the Pinentry may include an extra note on the origin. Sup-
ported values for origin are: local which is the default, remote
to indicate a remote origin or browser for an operation requested
by a web browser.

--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 ex-
pected 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 environ-
ments 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 signa-
ture seems to be older than the key due to clock problems. This
option makes these checks just a warning. See also --ig-
nore-valid-from for timestamp issues on subkeys.

--ignore-valid-from
GnuPG normally does not select and use subkeys created in the fu-
ture. 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. It is required to decrypt old messages which did not
use an MDC. It may also be useful if a message is partially gar-
bled, but it is necessary to get as much data as possible out of
that garbled message. Be aware that a missing or failed MDC can
be an indication of an attack. Use with great caution; see also
option --rfc2440.

--allow-old-cipher-algos
Old cipher algorithms like 3DES, IDEA, or CAST5 encrypt data us-
ing blocks of 64 bits; modern algorithms use blocks of 128 bit
instead. To avoid certain attack on these old algorithms it is
suggested not to encrypt more than 150 MiByte using the same key.
For this reason gpg does not allow the use of 64 bit block size
algorithms for encryption unless this option is specified. Some
compliance modes already set or clear this flag and thus this
flag should be used after a compliance mode setting.

--allow-weak-digest-algos
Signatures made with known-weak digest algorithms are normally
rejected with an ``invalid digest algorithm'' message. This op-
tion 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 algo-
rithms.

--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.

--allow-weak-key-signatures
To avoid a minor risk of collision attacks on third-party key
signatures made using SHA-1, those key signatures are considered
invalid. This options allows one to override this restriction.

--override-compliance-check
This was a temporary introduced option and has no more effect.

--no-default-keyring
Do not add the default keyring to the list of keyrings. Note that
GnuPG needs for almost all operations a keyring. Thus if you use
this option and do not provide alternate keyrings via --keyring,
then GnuPG will still use the default keyring.

Note that if the option use-keyboxd is enabled in ‘common.conf’,
no keyrings are used at all and keys are all maintained by the
keyboxd process in its own database.

--no-keyring
Do not use any keyring at all. This overrides the default and
all options which specify 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.

--list-signatures
--list-sigs
Same as --list-keys, but the signatures are listed too. This
command has the same effect as using --list-keys with
--with-sig-list. Note that in contrast to --check-signatures the
key signatures are not verified. This command can be used to
create a list of signing keys missing in the local keyring; for
example:

gpg --list-sigs --with-colons USERID | \
awk -F: '$1=="sig" && $2=="?" {if($13){print $13}else{print $5}}'

--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-ses-
sion-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 mes-
sages ever encrypted for one secret key.

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

--override-session-key string
--override-session-key-fd fd
Don't use the public key but the session key string respective
the session key taken from the first line read from file descrip-
tor fd. 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 en-
crypted message; using this option you can do this without hand-
ing out the secret key. Note that using --override-session-key
may reveal the session key to all local users via the global
process table. Often it is useful to combine this option with
--no-keyring.

--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 --de-
fault-sig-expire is used. --no-ask-sig-expire disables this op-
tion.

--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 --de-
fault-cert-expire is used. --no-ask-cert-expire disables this op-
tion.

--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".

--default-new-key-algo string
This option can be used to change the default algorithms for key
generation. The string is similar to the arguments required for
the command --quick-add-key but slightly different. You need to
consult the source code to learn the details. Note that the ad-
vanced key generation commands can always be used to specify a
key algorithm directly. Setting a compliance mode will set or
clear this flag, so it should only be used after a compliance
mode setting.

--no-auto-trust-new-key
When creating a new key the ownertrust of the new key is set to
ultimate. This option disables this and the user needs to manu-
ally assign an ownertrust value.

--force-sign-key
This option modifies the behaviour of the commands
--quick-sign-key, --quick-lsign-key, and the "sign" sub-commands
of --edit-key by forcing the creation of a key signature, even if
one already exists.

--forbid-gen-key
This option is intended for use in the global config file to dis-
allow the use of generate key commands. Those commands will then
fail with the error code for Not Enabled.

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

--allow-multiple-messages

--no-allow-multiple-messages
These are obsolete options; they have no more effect since GnuPG
2.2.8.

--enable-special-filenames
This option enables a mode in which filenames of the form ‘-&n’,
where n is a non-negative decimal number, refer to the file de-
scriptor 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-key menu.

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

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

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

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

--gpgconf-test
This is more or less dummy action. However it parses the config-
uration 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.

--chuid uid
Change the current user to uid which may either be a number or a
name. This can be used from the root account to run gpg for an-
other user. If uid is not the current UID a standard PATH is set
and the envvar GNUPGHOME is unset. To override the latter the
option --homedir can be used. This option has only an effect
when used on the command line. This option has currently no ef-
fect at all on Windows.

Deprecated 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 was useful when
communicating between two platforms with different line ending
conventions (UNIX-like to Mac, Mac to Windows, etc).
--no-textmode disables this option, and is the default. Note
that this is a legacy option which should not anymore be used by
any modern software.

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

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

--show-photos
--no-show-photos
Causes --list-keys, --list-signatures, --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.

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

--show-policy-url
--no-show-policy-url
Show policy URLs in the --list-signatures or --check-signatures
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.

--personal-aead-preferences string
This option is deprecated and has no more effect since version
2.3.9.

--aead-algo name
This option is deprecated and has no more effect since version
2.3.9.

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

gpg --clear-sign file
make a cleartext 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 [datafile]
Verify the signature of the file but do not output the data un-
less requested. The second form is used for detached signatures,
where sigfile is the detached signature (either ASCII armored or
binary) and datafile 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. If the option --output is also
used the signed data is written to the file specified by that op-
tion; use - to write the signed data to stdout.

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 en-
tire list of ways to specify a key:

By key Id.
This format is deduced from the length of the string and its con-
tent 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 con-
tent or the 0x prefix. Note, that only the 20 byte version fin-
gerprint is available with gpgsm (i.e. the SHA-1 hash of the cer-
tificate).

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 be-
cause this is the de-facto standard on how to present X.509 finger-
prints. gpg also allows the use of the space separated SHA-1 finger-
print 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 partial match on an email address.
This is indicated by prefixing the search string with an @. This
uses a substring search but considers only the mail address (i.e.
inside the angle brackets).

@heinrichh

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 has been re-
ordered 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 RFC-2253 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.

&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

. and + prefixes
These prefixes are reserved for looking up mails anchored at the
end and for a word search mode. They are not yet implemented and
using them is undefined.

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 encod-
ing as meta data.

FILTER EXPRESSIONS
The options --import-filter and --export-filter use expressions with
this syntax (square brackets indicate an optional part and curly braces
a repetition, white space between the elements are allowed):

[lc] {[{flag}] PROPNAME op VALUE [lc]}

The name of a property (PROPNAME) may only consist of letters, digits
and underscores. The description for the filter type describes which
properties are defined. If an undefined property is used it evaluates
to the empty string. Unless otherwise noted, the VALUE must always be
given and may not be the empty string. No quoting is defined for the
value, thus the value may not contain the strings && or ||, which are
used as logical connection operators. The flag -- can be used to remove
this restriction.

Numerical values are computed as long int; standard C notation applies.
lc is the logical connection operator; either && for a conjunction or ||
for a disjunction. A conjunction is assumed at the begin of an expres-
sion. Conjunctions have higher precedence than disjunctions. If VALUE
starts with one of the characters used in any op a space after the op is
required.

The supported operators (op) are:

=~ Substring must match.

!~ Substring must not match.

= The full string must match.

<> The full string must not match.

== The numerical value must match.

!= The numerical value must not match.

<= The numerical value of the field must be LE than the value.

< The numerical value of the field must be LT than the value.

> The numerical value of the field must be GT than the value.

>= The numerical value of the field must be GE than the value.

-le The string value of the field must be less or equal than the
value.

-lt The string value of the field must be less than the value.

-gt The string value of the field must be greater than the value.

-ge The string value of the field must be greater or equal than the
value.

-n True if value is not empty (no value allowed).

-z True if value is empty (no value allowed).

-t Alias for "PROPNAME != 0" (no value allowed).

-f Alias for "PROPNAME == 0" (no value allowed).

Values for flag must be space separated. The supported flags are:

-- VALUE spans to the end of the expression.

-c The string match in this part is done case-sensitive.

-t Leading and trailing spaces are not removed from VALUE. The op-
tional single space after op is here required.

The filter options concatenate several specifications for a filter of
the same type. For example the four options in this example:

--import-filter keep-uid="uid =~ Alfa"
--import-filter keep-uid="&& uid !~ Test"
--import-filter keep-uid="|| uid =~ Alpha"
--import-filter keep-uid="uid !~ Test"

which is equivalent to

--import-filter \
keep-uid="uid =~ Alfa" && uid !~ Test" || uid =~ Alpha" && "uid !~ Test"

imports only the user ids of a key containing the strings "Alfa" or "Al-
pha" but not the string "test".

TRUST VALUES
Trust values are used to indicate ownertrust and validity of keys and
user IDs. They are displayed with letters or strings:

-
unknown
No ownertrust assigned / not yet calculated.

e
expired

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

q
undefined, undef
Not enough information for calculation.

n
never Never trust this key.

m
marginal
Marginally trusted.

f
full Fully trusted.

u
ultimate
Ultimately trusted.

r
revoked
For validity only: the key or the user ID has been revoked.

?
err The program encountered an unknown trust value.

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 de-
fault name may be changed on the command line (see: [gpg-option
--options]). You should backup this file.

common.conf
This is an optional configuration file read by gpg on startup.
It may contain options pertaining to all components of GnuPG.
Its current main use is for the "use-keyboxd" option. If the de-
fault home directory ‘~/.gnupg’ does not exist, GnuPG creates
this directory and a ‘common.conf’ file with "use-keyboxd".

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 existing users a small helper
script is provided to create these files (see: [addgnupghome]).

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

~/.gnupg
This is the default home directory which is used if neither the
environment variable GNUPGHOME nor the option --homedir is given.

~/.gnupg/pubring.gpg
The public keyring using a legacy format. You should backup this
file.

If this file is not available, gpg defaults to the new keybox
format and creates a file ‘pubring.kbx’ unless that file already
exists in which case that file will also be used for OpenPGP
keys.

Note that in the case that both files, ‘pubring.gpg’ and ‘pub-
ring.kbx’ exists but the latter has no OpenPGP keys, the legacy
file ‘pubring.gpg’ will be used. Take care: GnuPG versions be-
fore 2.1 will always use the file ‘pubring.gpg’ because they do
not know about the new keybox format. In the case that you have
to use GnuPG 1.4 to decrypt archived data you should keep this
file.

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

~/.gnupg/pubring.kbx
The public keyring using the new keybox format. This file is
shared with gpgsm. You should backup this file. See above for
the relation between this file and it predecessor.

To convert an existing ‘pubring.gpg’ file to the keybox format,
you first backup the ownertrust values, then rename ‘pubring.gpg’
to ‘publickeys.backup’, so it won’t be recognized by any GnuPG
version, run import, and finally restore the ownertrust values:

$ cd ~/.gnupg
$ gpg --export-ownertrust >otrust.lst
$ mv pubring.gpg publickeys.backup
$ gpg --import-options restore --import publickeys.backup
$ gpg --import-ownertrust otrust.lst

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

~/.gnupg/secring.gpg
The legacy secret keyring as used by GnuPG versions before 2.1.
It is not used by GnuPG 2.1 and later. You may want to keep it
in case you have to use GnuPG 1.4 to decrypt archived data.

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

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

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

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

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

~/.gnupg/openpgp-revocs.d/
This is the directory where gpg stores pre-generated revocation
certificates. The file name corresponds to the OpenPGP finger-
print 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 these 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.

Operation is further controlled by a few environment variables:

HOME Used to locate the default home directory.

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

GPG_AGENT_INFO
This variable is obsolete; it was used by GnuPG versions before
2.1.

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

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

LANGUAGE
Apart from its use by GNU, it is used in the W32 version to over-
ride 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.

GNUPG_BUILD_ROOT
This variable is only used by the regression test suite as a
helper under operating systems without proper support to figure
out the name of a process' text file.

GNUPG_EXEC_DEBUG_FLAGS
This variable allows one to enable diagnostics for process man-
agement. A numeric decimal value is expected. Bit 0 enables
general diagnostics, bit 1 enables certain warnings on Windows.

When calling the gpg-agent component gpg sends a set of environment
variables to gpg-agent. The names of these variables can be listed us-
ing the command:

gpg-connect-agent 'getinfo std_env_names' /bye | awk '$1=="D" {print $2}'

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

Programmatic use of GnuPG

Please consider using GPGME instead of calling gpg directly. GPGME of-
fers a stable, backend-independent interface for many cryptographic op-
erations. It supports OpenPGP and S/MIME, and also allows interaction
with various GnuPG components.

GPGME provides a C-API, and comes with bindings for C++, Qt, and Python.
Bindings for other languages are available.

Ephemeral home directories

Sometimes you want to contain effects of some operation, for example you
want to import a key to inspect it, but you do not want this key to be
added to your keyring. In earlier versions of GnuPG, it was possible to
specify alternate keyring files for both public and secret keys. In
modern GnuPG versions, however, we changed how secret keys are stored in
order to better protect secret key material, and it was not possible to
preserve this interface.

The preferred way to do this is to use ephemeral home directories. This
technique works across all versions of GnuPG.

Create a temporary directory, create (or copy) a configuration that
meets your needs, make gpg use this directory either using the environ-
ment variable GNUPGHOME, or the option --homedir. GPGME supports this
too on a per-context basis, by modifying the engine info of contexts.
Now execute whatever operation you like, import and export key material
as necessary. Once finished, you can delete the directory. All GnuPG
backend services that were started will detect this and shut down.

The quick key manipulation interface

Recent versions of GnuPG have an interface to manipulate keys without
using the interactive command --edit-key. This interface was added
mainly for the benefit of GPGME (please consider using GPGME, see the
manual subsection ``Programmatic use of GnuPG''). This interface is de-
scribed in the subsection ``How to manage your keys''.

Unattended key generation

The command --generate-key may be used along with the option --batch for
unattended key generation. This is the most flexible way of generating
keys, but it is also the most complex one. Consider using the quick key
manipulation interface described in the previous subsection ``The quick
key manipulation interface''.

The parameters for the key are either read from stdin or given as a file
on the command line. The format of the parameter file is as follows:
Text only, line length is limited to about 1000 characters. UTF-8 en-
coding must be used to specify non-ASCII characters. Empty lines are
ignored. Leading and trailing white space is ignored. A hash sign as
the first non white space character indicates a comment line. Control
statements are indicated by a leading percent sign, their arguments are
separated by white space from the keyword. Parameters are specified by
a keyword, followed by a colon; arguments are separated by white space.
The first parameter must be ‘Key-Type’ but control statements may be
placed anywhere. The order of the parameters does not matter except for
‘Key-Type’. The parameters are only used for the generated keyblock
(primary and subkeys); parameters from previous sets are not used. Some
syntax checks may be performed. Key commences when either the end of
the parameter file is reached, the next ‘Key-Type’ parameter is encoun-
tered, or the control statement ‘%commit’ is encountered.

Control statements:

%echo text
Print text as diagnostic.

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

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

%pubring filename
Do not write the key to the default or commandline given keyring
but to filename. This must be given before the first commit to
take place, duplicate specification of the same filename is ig-
nored, the last filename before a commit is used. The filename
is used until a new filename is used (at commit points) and all
keys are written to that file. If a new filename is given, this
file is created (and overwrites an existing one).

See the previous subsection ``Ephemeral home directories'' for a
more robust way to contain side-effects.

%secring filename
This option is a no-op for GnuPG 2.1 and later.

See the previous subsection ``Ephemeral home directories''.

%ask-passphrase
%no-ask-passphrase
This option is a no-op since GnuPG version 2.1.

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

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

General Parameters:

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

Key-Length: nbits
The requested length of the generated key in bits. The default
is returned by running the command ‘gpg --gpgconf-list’. For ECC
keys this parameter is ignored.

Key-Curve: curve
The requested elliptic curve of the generated key. This is a re-
quired parameter for ECC keys. It is ignored for non-ECC keys.

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

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

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

Subkey-Length: nbits
Length of the secondary key (subkey) in bits. The default is re-
turned by running the command ‘gpg --gpgconf-list’.

Subkey-Curve: curve
Key curve for a subkey; similar to ‘Key-Curve’.

Subkey-Usage: usage-list
Key usage lists for a subkey; similar to ‘Key-Usage’.

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

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

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

Creation-Date: iso-date
Set the creation date of the key as stored in the key information
and which is also part of the fingerprint calculation. Either a
date like "1986-04-26" or a full timestamp like "19860426T042640"
may be used. The time is considered to be UTC. The special no-
tation "seconds=N" may be used to directly specify a the number
of seconds since Epoch (Unix time). If it is not given the cur-
rent time is used.

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

Revoker: algo:fpr [sensitive]
Add a designated revoker to the generated key. Algo is the pub-
lic key algorithm of the designated revoker (i.e. RSA=1, DSA=17,
etc.) fpr is the fingerprint of the designated revoker. fpr may
not contain spaces or colons. The optional ‘sensitive’ flag
marks the designated revoker as sensitive information. Only v4
and v5 keys may be designated revokers.

Keyserver: string
This is an optional parameter that specifies the preferred key-
server URL for the key.

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

Here is an example on how to create a key in an ephemeral home direc-
tory:
$ export GNUPGHOME="$(mktemp -d)"
$ cat >foo <<EOF
%echo Generating a basic OpenPGP key
Key-Type: DSA
Key-Length: 1024
Subkey-Type: ELG-E
Subkey-Length: 1024
Name-Real: Joe Tester
Name-Comment: with stupid passphrase
Name-Email: joe@foo.bar
Expire-Date: 0
Passphrase: abc
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done
EOF
$ gpg --batch --generate-key foo
[...]
$ gpg --list-secret-keys
/tmp/tmp.0NQxB74PEf/pubring.kbx
-------------------------------
sec dsa1024 2016-12-16 [SCA]
768E895903FC1C44045C8CB95EEBDB71E9E849D0
uid [ultimate] Joe Tester (with stupid passphrase) <joe@foo.bar>
ssb elg1024 2016-12-16 [E]

If you want to create a key with the default algorithms you would use
these parameters:
%echo Generating a default key
Key-Type: default
Subkey-Type: default
Name-Real: Joe Tester
Name-Comment: with stupid passphrase
Name-Email: joe@foo.bar
Expire-Date: 0
Passphrase: abc
# Do a commit here, so that we can later print "done" :-)
%commit
%echo done

BUGS
On older systems this program should be installed as setuid(root). This
is necessary to lock memory pages. Locking memory pages prevents the op-
erating 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 be-
ing 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 https://bugs.gnupg.org.

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

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

info gnupg

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

GnuPG 2.4.7 2024-11-22 GPG(1)

Generated by dwww version 1.16 on Tue Dec 16 04:53:14 CET 2025.