manpagez: man pages & more
man gpg-card(1)
Home | html | info | man
gpg-card(1)                  GNU Privacy Guard 2.6                 gpg-card(1)


NAME

       gpg-card - Administrate Smart Cards


SYNOPSIS

       gpg-card [options]
       gpg-card [options] command { -- command }



DESCRIPTION

       The gpg-card is used to administrate smart cards and USB tokens.  It
       provides a superset of features from gpg --card-edit an can be
       considered a frontend to scdaemon which is a daemon started by
       gpg-agent to handle smart cards.

       If gpg-card is invoked without commands an interactive mode is used.

       If gpg-card is invoked with one or more commands the same commands as
       available in the interactive mode are run from the command line.  These
       commands need to be delimited with a double-dash.  If a double-dash or
       a shell specific character is required as part of a command the entire
       command needs to be put in quotes.  If one of those commands returns an
       error the remaining commands are not anymore run unless the command was
       prefixed with a single dash.

       A list of commands is available by using the command help and a brief
       description of each command is printed by using help CMD.  See the
       section COMMANDS for a full description.

       See the NOTES sections for instructions pertaining to specific cards or
       card applications.



COMMANDS

       gpg-card understands the following commands, which have options of
       their own.  The pseudo-option `--' can be used to separate command
       options from arguments; if this pseudo option is used on the command
       line the entire command with options and arguments must be quoted, so
       that it is not mixed up with the `--' as used on the command line to
       separate commands.  Note that a short online help is available for all
       commands by prefixing them with ``help''.  Command completion in the
       interactive mode is also supported.



       AUTHENTICATE [--setkey] [--raw] [< file]|key]
       AUTH   Authenticate to the card.  Perform a mutual authentication
              either by reading the key from file or by taking it from the
              command line as key.  Without the option --raw the key is
              expected to be hex encoded.  To install a new administration key
              --setkey is used; this requires a prior authentication with the
              old key.  This is used with PIV cards.



       CAFPR [--clear] N
              Change the CA fingerprint number N of an OpenPGP card.  N must
              be in the range 1 to 3.  The option --clear clears the specified
              CA fingerprint N or all of them if N is 0 or not given.


       FACTORY-RESET
              Do a complete reset of some OpenPGP and PIV cards.  This command
              deletes all data and keys and resets the PINs to their default.
              Don't worry, you need to confirm before the command proceeds.


       FETCH  Retrieve a key using the URL data object of an OpenPGP card or
              if that is missing using the stored fingerprint.


       FORCESIG
              Toggle the forcesig flag of an OpenPGP card.


       GENERATE [--force] [--algo=algo{+algo2}] keyref
              Create a new key on a card.  Use --force to overwrite an
              existing key.  Use "help" for algo to get a list of known
              algorithms.  For OpenPGP cards several algos may be given.  Note
              that the OpenPGP key generation is done interactively unless
              --algo or keyref are given.


       KDF-SETUP
              Prepare the OpenPGP card KDF feature for this card.


       LANG [--clear]
              Change the language info for the card.  This info can be used by
              applications for a personalized greeting.  Up to 4 two-digit
              language identifiers can be entered as a preference.  The option
              --clear removes all identifiers.  GnuPG does not use this info.


       LIST [--cards] [--apps] [--info] [--no-key-lookup] [n] [app]
       L      This command reads all information from the current card and
              display them in a human readable format.  The first section
              shows generic information vaialable for all cards.  The next
              section shows information pertaining to keys which depend on the
              actual card and application.

              With n given select and list the n-th card; with app also given
              select that application.  To select an app on the current card
              use "-" for n.  The serial number of the card may be used
              instead of n.

              The option --cards lists the serial numbers of available cards.
              The option --apps lists all card applications.  The option
              --info selects a card and prints its serial number.  The option
              --no-key-lookup suppresses the listing of matching OpenPGP or
              X.509 keys.



       LOGIN [--clear] [< file]
              Set the login data object of OpenPGP cards.  If file is given
              the data is is read from that file.  This allows one to store
              binary data in the login field.  The option --clear deletes the
              login data object.


       NAME [--clear]
              Set the name field of an OpenPGP card.  With option --clear the
              stored name is cleared off the card.


       PASSWD [--reset|--nullpin] [pinref]
              Change or unblock the PINs.  Note that in interactive mode and
              without a pinref a menu is presented for certain cards."  In
              non-interactive mode and without a pinref a default value i used
              for these cards.  The option --reset is used with TCOS cards to
              reset the PIN using the PUK or vice versa; the option --nullpin
              is used for these cards to set the initial PIN.


       PRIVATEDO [--clear] n [< file]
              Change the private data object n of an OpenPGP card.  n must be
              in the range 1 to 4.  If file is given the data is is read from
              that file.  The option --clear clears the data.


       QUIT
       Q      Stop processing and terminate gpg-card.


       READCERT [--openpgp] certref > file
              Read the certificate for key certref and store it in file.  With
              option --openpgp an OpenPGP keyblock wrapped in a dedicated CMS
              content type (OID=1.3.6.1.4.1.11591.2.3.1) is expected and
              extracted to file.  Note that for current OpenPGP cards a
              certificate may only be available at the certref "OPENPGP.3".


       RESET  Send a reset to the card daemon.


       SALUTATION [--clear]
       SALUT  Change the salutation info for the card.  This info can be used
              by applications for a personalized greeting.  The option --clear
              removes this data object.  GnuPG does not use this info.


       UIF N [on|off|permanent]
              Change the User Interaction Flag.  That flags tells whether the
              confirmation button of a token shall be used.  n must in the
              range 1 to 3.  "permanent" is the same as "on" but the flag
              can't be changed anymore.


       UNBLOCK
              Unblock a PIN using a PUK or Reset Code.  Note that OpenPGP
              cards prior to version 2 can't use this; instead the PASSWD can
              be used to set a new PIN.


       URL [--clear]
              Set the URL data object of an OpenPGP card.  That data object
              can be used by by gpg's --fetch command to retrieve the full
              public key.  The option --clear deletes the content of that data
              object.


       VERIFY [chvid]
              Verify the PIN identified by chvid or the default PIN.


       WRITECERT certref < file
       WRITECERT --openpgp certref [< file|fpr]
       WRITECERT --clear certref
              Write a certificate to the card under the id certref.  The
              option --clear removes the certificate from the card.  The
              option --openpgp expects an OpenPGP keyblock and stores it
              encapsulated in a CMS container; the keyblock is taken from file
              or directly from the OpenPGP key identified by fingerprint fpr.


       WRITEKEY [--force] keyref keygrip
              Write a private key object identified by keygrip to the card
              under the id keyref.  Option --force allows overwriting an
              existing key.


       CHECKKEYS [--ondisk] [--delete-clear-copy] [--delete-protected-copy]
              Print a list of keys noticed on all inserted cards.  With
              --ondisk only smartcard keys with a copy on disk are listed.
              With --delete-clear-copy copies of smartcard keys stored on disk
              without any protection will be deleted.  With
              --delete-protected-copy password protected copies of smartcard
              keys stored on disk will be deleted.

              This command creates missing shadow keys.  The delete options
              print the status of the keys before they are deleted.

              The format of the output is:

              Serial number
                     A hex-string with the serial number of the card.

              Type   This gives the type of the card's application.  For
                     example "OpenPGP" or "PIV".

              Keygrip
                     A hex-string identifying a key.

              Keyref The application slot where the key is stored on the card.
                     For example "OpenPGP.1"

              Status The status of the key.  The most common value is
                     "shadowed" for a key where only the public key along with
                     the card's serial number is stored on the disk.  The
                     value "clear" indicates that a copy of the card's key is
                     stored unprotected on disk.  The value "protected"
                     indicated that a copy of the car's key is stored on disk
                     but is protected by a password.  The value "error" may
                     also be shown if there was a problem reading information
                     from the card.


       YUBIKEY cmd args
              Various commands pertaining to Yubikey tokens with cmd being:

              LIST   List supported and enabled Yubikey applications.

              ENABLE usb|nfc|all [otp|u2f|opgp|piv|oath|fido2|all]
              DISABLE
                     Enable or disable the specified or all applications on
                     the given interface.



NOTES (OPENPGP)

       The support for OpenPGP cards in gpg-card is not yet complete.  For
       missing features, please continue to use gpg --card-edit.



NOTES (PIV)

       GnuPG has support for PIV cards (``Personal Identity Verification'' as
       specified by NIST Special Publication 800-73-4).  This section
       describes how to initialize (personalize) a fresh Yubikey token
       featuring the PIV application (requires Yubikey-5).  We assume that the
       credentials have not yet been changed and thus are:

       Authentication key
              This is a 24 byte key described by the hex string
              010203040506070801020304050607080102030405060708.

       PIV Application PIN
              This is the string 123456.

       PIN Unblocking Key
              This is the string 12345678.

       See the example section on how to change these defaults.  For
       production use it is important to use secure values for them.  Note
       that the Authentication Key is not queried via the usual Pinentry
       dialog but needs to be entered manually or read from a file.  The use
       of a dedicated machine to personalize tokens is strongly suggested.

       To see what is on the card, the command list can be given.  We will use
       the interactive mode in the following (the string gpg/card> is the
       prompt).  An example output for a fresh card is:

         gpg/card> list
         Reader ...........: 1050:0407:X:0
         Card type ........: yubikey
         Card firmware ....: 5.1.2
         Serial number ....: D2760001240102010006090746250000
         Application type .: OpenPGP
         Version ..........: 2.1
         [...]

       It can be seen by the ``Application type'' line that GnuPG selected the
       OpenPGP application of the Yubikey.  This is because GnuPG assigns the
       highest priority to the OpenPGP application.  To use the PIV
       application of the Yubikey several methods can be used:

       With a Yubikey 5 or later the OpenPGP application on the Yubikey can be
       disabled:

         gpg/card> yubikey disable all opgp
         gpg/card> yubikey list
         Application  USB    NFC
         -----------------------
         OTP          yes    yes
         U2F          yes    yes
         OPGP         no     no
         PIV          yes    no
         OATH         yes    yes
         FIDO2        yes    yes
         gpg/card> reset

       The reset is required so that the GnuPG system rereads the card.  Note
       that disabled applications keep all their data and can at any time be
       re-enabled (use `help yubikey').

       Another option, which works for all Yubikey versions, is to disable the
       support for OpenPGP cards in scdaemon.  This is done by adding the line

         disable-application openpgp

       to `~/.gnupg/scdaemon.conf' and by restarting scdaemon, either by
       killing the process or by using `gpgconf --kill scdaemon'.  Finally the
       default order in which card applications are tried by scdaemon can be
       changed.   For example to prefer PIV over OpenPGP it is sufficient to
       add

         application-priority piv

       to `~/.gnupg/scdaemon.conf' and to restart scdaemon.  This has an
       effect only on tokens which support both, PIV and OpenPGP, but does not
       hamper the use of OpenPGP only tokens.

       With one of these methods employed the list command of gpg-card shows
       this:

         gpg/card> list
         Reader ...........: 1050:0407:X:0
         Card type ........: yubikey
         Card firmware ....: 5.1.2
         Serial number ....: FF020001008A77C1
         Application type .: PIV
         Version ..........: 1.0
         Displayed s/n ....: yk-9074625
         PIN usage policy .: app-pin
         PIN retry counter : - 3 -
         PIV authentication: [none]
               keyref .....: PIV.9A
         Card authenticat. : [none]
               keyref .....: PIV.9E
         Digital signature : [none]
               keyref .....: PIV.9C
         Key management ...: [none]
               keyref .....: PIV.9D

       In case several tokens are plugged into the computer, gpg-card will
       show only one.  To show another token the number of the token (0, 1, 2,
       ...) can be given as an argument to the list command.  The command
       `list --cards' prints a list of all inserted tokens.

       Note that the ``Displayed s/n'' is printed on the token and also shown
       in Pinentry prompts asking for the PIN.  The four standard key slots
       are always shown, if other key slots are initialized they are shown as
       well.  The PIV authentication key (internal reference PIV.9A) is used
       to authenticate the card and the card holder.  The use of the
       associated private key is protected by the Application PIN which needs
       to be provided once and the key can the be used until the card is reset
       or removed from the reader or USB port.  GnuPG uses this key with its
       Secure Shell support.  The Card authentication key (PIV.9E) is also
       known as the CAK and used to support physical access applications.  The
       private key is not protected by a PIN and can thus immediately be used.
       The Digital signature key (PIV.9C) is used to digitally sign documents.
       The use of the associated private key is protected by the Application
       PIN which needs to be provided for each signing operation.  The Key
       management key (PIV.9D) is used for encryption.  The use of the
       associated private key is protected by the Application PIN which needs
       to be provided only once so that decryption operations can then be done
       until the card is reset or removed from the reader or USB port.

       We now generate three of the four keys.  Note that GnuPG does currently
       not use the the Card authentication key; however, that key is mandatory
       by the PIV standard and thus we create it too.  Key generation requires
       that we authenticate to the card.  This can be done either on the
       command line (which would reveal the key):

         gpg/card> auth 010203040506070801020304050607080102030405060708

       or by reading the key from a file.  That file needs to consist of one
       LF terminated line with the hex encoded key (as above):

         gpg/card> auth < myauth.key

       As usual `help auth' gives help for this command.  An error message is
       printed if a non-matching key is used.  The authentication is valid
       until a reset of the card or until the card is removed from the reader
       or the USB port.  Note that that in non-interactive mode the `<' needs
       to be quoted so that the shell does not interpret it as a its own
       redirection symbol.


       Here are the actual commands to generate the keys:

         gpg/card> generate --algo=nistp384 PIV.9A
         PIV card no. yk-9074625 detected
         gpg/card> generate --algo=nistp256 PIV.9E
         PIV card no. yk-9074625 detected
         gpg/card> generate --algo=rsa2048 PIV.9C
         PIV card no. yk-9074625 detected

       If a key has already been created for one of the slots an error will be
       printed; to create a new key anyway the option `--force' can be used.
       Note that only the private and public keys have been created but no
       certificates are stored in the key slots.  In fact, GnuPG uses its own
       non-standard method to store just the public key in place of the
       certificate.  Other application will not be able to make use these keys
       until gpgsm or another tool has been used to create and store the
       respective certificates.   Let us see what the list command now shows:

         gpg/card> list
         Reader ...........: 1050:0407:X:0
         Card type ........: yubikey
         Card firmware ....: 5.1.2
         Serial number ....: FF020001008A77C1
         Application type .: PIV
         Version ..........: 1.0
         Displayed s/n ....: yk-9074625
         PIN usage policy .: app-pin
         PIN retry counter : - 3 -
         PIV authentication: 213D1825FDE0F8240CB4E4229F01AF90AC658C2E
               keyref .....: PIV.9A  (auth)
               algorithm ..: nistp384
         Card authenticat. : 7A53E6CFFE7220A0E646B4632EE29E5A7104499C
               keyref .....: PIV.9E  (auth)
               algorithm ..: nistp256
         Digital signature : 32A6C6FAFCB8421878608AAB452D5470DD3223ED
               keyref .....: PIV.9C  (sign,cert)
               algorithm ..: rsa2048
         Key management ...: [none]
               keyref .....: PIV.9D

       The primary information for each key is the keygrip, a 40 byte hex-
       string identifying the key.  This keygrip is a unique identifier for
       the specific parameters of a key.  It is used by gpg-agent and other
       parts of GnuPG to associate a private key to its protocol specific
       certificate format (X.509, OpenPGP, or SecureShell).  Below the keygrip
       the key reference along with the key usage capabilities are show.
       Finally the algorithm is printed in the format used by  {gpg}.  At that
       point no other information is shown because for these new keys gpg
       won't be able to find matching certificates.

       Although we could have created the Key management key also with the
       generate command, we will create that key off-card so that a backup
       exists.  To accomplish this a key needs to be created with either gpg
       or gpgsm or imported in one of these tools.  In our example we create a
       self-signed X.509 certificate (exit the gpg-card tool, first):

         $ gpgsm --gen-key -o encr.crt
            (1) RSA
            (2) Existing key
            (3) Existing key from card
         Your selection? 1
         What keysize do you want? (3072) 2048
         Requested keysize is 2048 bits
         Possible actions for a RSA key:
            (1) sign, encrypt
            (2) sign
            (3) encrypt
         Your selection? 3
         Enter the X.509 subject name: CN=Encryption key for yk-9074625,O=example,C=DE
         Enter email addresses (end with an empty line):
         > otto@example.net
         >
         Enter DNS names (optional; end with an empty line):
         >
         Enter URIs (optional; end with an empty line):
         >
         Create self-signed certificate? (y/N) y
         These parameters are used:
             Key-Type: RSA
             Key-Length: 2048
             Key-Usage: encrypt
             Serial: random
             Name-DN: CN=Encryption key for yk-9074625,O=example,C=DE
             Name-Email: otto@example.net

         Proceed with creation? (y/N)
         Now creating self-signed certificate.  This may take a while ...
         gpgsm: about to sign the certificate for key: &34798AAFE0A7565088101CC4AE31C5C8C74461CB
         gpgsm: certificate created
         Ready.
         $ gpgsm --import encr.crt
         gpgsm: certificate imported
         gpgsm: total number processed: 1
         gpgsm:               imported: 1

       Note the last step which imported the created certificate.  If you you
       instead created a certificate signing request (CSR) instead of a self-
       signed certificate and sent this off to a CA you would do the same
       import step with the certificate received from the CA.  Take note of
       the keygrip (prefixed with an ampersand) as shown during the
       certificate creation or listed it again using `gpgsm --with-keygrip -k
       otto@example.net'.  Now to move the key and certificate to the card
       start gpg-card again and enter:

         gpg/card> writekey PIV.9D 34798AAFE0A7565088101CC4AE31C5C8C74461CB
         gpg/card> writecert PIV.9D < encr.crt

       If you entered a passphrase to protect the private key, you will be
       asked for it via the Pinentry prompt.  On success the key and the
       certificate has been written to the card and a list command shows:

         [...]
         Key management ...: 34798AAFE0A7565088101CC4AE31C5C8C74461CB
               keyref .....: PIV.9D  (encr)
               algorithm ..: rsa2048
               used for ...: X.509
                 user id ..: CN=Encryption key for yk-9074625,O=example,C=DE
                 user id ..: <otto@example.net>

       In case the same key (identified by the keygrip) has been used for
       several certificates you will see several ``used for'' parts.  With
       this the encryption key is now fully functional and can be used to
       decrypt messages encrypted to this certificate.  Take care: the
       original key is still stored on-disk and should be moved to a backup
       medium.  This can simply be done by copying the file
       `34798AAFE0A7565088101CC4AE31C5C8C74461CB.key' from the directory
       `~/.gnupg/private-keys-v1.d/' to the backup medium and deleting the
       file at its original place.

       The final example is to create a self-signed certificate for digital
       signatures.  Leave gpg-card using quit or by pressing Control-D and use
       gpgsm:

         $ gpgsm --learn
         $ gpgsm --gen-key -o sign.crt
         Please select what kind of key you want:
            (1) RSA
            (2) Existing key
            (3) Existing key from card
         Your selection? 3
         Serial number of the card: FF020001008A77C1
         Available keys:
            (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384
            (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256
            (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048
            (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048
         Your selection? 3
         Possible actions for a RSA key:
            (1) sign, encrypt
            (2) sign
            (3) encrypt
         Your selection? 2
         Enter the X.509 subject name: CN=Signing key for yk-9074625,O=example,C=DE
         Enter email addresses (end with an empty line):
         > otto@example.net
         >
         Enter DNS names (optional; end with an empty line):
         >
         Enter URIs (optional; end with an empty line):
         >
         Create self-signed certificate? (y/N)
         These parameters are used:
             Key-Type: card:PIV.9C
             Key-Length: 1024
             Key-Usage: sign
             Serial: random
             Name-DN: CN=Signing key for yk-9074625,O=example,C=DE
             Name-Email: otto@example.net

         Proceed with creation? (y/N) y
         Now creating self-signed certificate.  This may take a while ...
         gpgsm: about to sign the certificate for key: &32A6C6FAFCB8421878608AAB452D5470DD3223ED
         gpgsm: certificate created
         Ready.
         $ gpgsm --import sign.crt
         gpgsm: certificate imported
         gpgsm: total number processed: 1
         gpgsm:               imported: 1

       The use of `gpgsm --learn' is currently necessary so that gpg-agent
       knows what keys are available on the card.  The need for this command
       will eventually be removed.  The remaining commands are similar to the
       creation of an on-disk key.  However, here we select the `Digital
       signature' key.  During the creation process you will be asked for the
       Application PIN of the card.  The final step is to write the
       certificate to the card using gpg-card:

         gpg/card> writecert PIV.9C < sign.crt

       By running list again we will see the fully initialized card:

         Reader ...........: 1050:0407:X:0
         Card type ........: yubikey
         Card firmware ....: 5.1.2
         Serial number ....: FF020001008A77C1
         Application type .: PIV
         Version ..........: 1.0
         Displayed s/n ....: yk-9074625
         PIN usage policy .: app-pin
         PIN retry counter : - [verified] -
         PIV authentication: 213D1825FDE0F8240CB4E4229F01AF90AC658C2E
               keyref .....: PIV.9A  (auth)
               algorithm ..: nistp384
         Card authenticat. : 7A53E6CFFE7220A0E646B4632EE29E5A7104499C
               keyref .....: PIV.9E  (auth)
               algorithm ..: nistp256
         Digital signature : 32A6C6FAFCB8421878608AAB452D5470DD3223ED
               keyref .....: PIV.9C  (sign,cert)
               algorithm ..: rsa2048
               used for ...: X.509
                 user id ..: CN=Signing key for yk-9074625,O=example,C=DE
                 user id ..: <otto@example.net>
         Key management ...: 34798AAFE0A7565088101CC4AE31C5C8C74461CB
               keyref .....: PIV.9D  (encr)
               algorithm ..: rsa2048
               used for ...: X.509
                 user id ..: CN=Encryption key for yk-9074625,O=example,C=DE
                 user id ..: <otto@example.net>

       It is now possible to sign and to encrypt with this card using gpgsm
       and to use the `PIV authentication' key with ssh:

         $ ssh-add -l
         384 SHA256:0qnJ0Y0ehWxKcx2frLfEljf6GCdlO55OZed5HqGHsaU cardno:yk-9074625 (ECDSA)

       As usual use ssh-add with the uppercase `-L' to list the public ssh
       key.  To use the certificates with Thunderbird or Mozilla, please
       consult the Scute manual for details.

       If you want to use the same PIV keys also for OpenPGP (for example on a
       Yubikey to avoid switching between OpenPGP and PIV), this is also
       possible:

         $ gpgsm --learn
         $ gpg --full-gen-key
         Please select what kind of key you want:
            (1) RSA and RSA (default)
            (2) DSA and Elgamal
            (3) DSA (sign only)
            (4) RSA (sign only)
           (14) Existing key from card
         Your selection? 14
         Serial number of the card: FF020001008A77C1
         Available keys:
            (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384 (auth)
            (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256 (auth)
            (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048 (cert,sign)
            (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048 (encr)
         Your selection? 3
         Please specify how long the key should be valid.
                  0 = key does not expire
               <n>  = key expires in n days
               <n>w = key expires in n weeks
               <n>m = key expires in n months
               <n>y = key expires in n years
         Key is valid for? (0)
         Key does not expire at all
         Is this correct? (y/N) y

         GnuPG needs to construct a user ID to identify your key.

         Real name:
         Email address: otto@example.net
         Comment:
         You selected this USER-ID:
             "otto@example.net"

         Change (N)ame, (C)omment, (E)mail or (O)kay/(Q)uit? o
         gpg: key C3AFA9ED971BB365 marked as ultimately trusted
         gpg: revocation certificate stored as '[...]D971BB365.rev'
         public and secret key created and signed.

         Note that this key cannot be used for encryption.  You may want to use
         the command "--edit-key" to generate a subkey for this purpose.
         pub   rsa2048 2019-04-04 [SC]
               7F899AE2FB73159DD68A1B20C3AFA9ED971BB365
         uid                      otto@example.net

       Note that you will be asked two times to enter the PIN of your PIV
       card.  If you run gpg in --expert mode you will also ge given the
       option to change the usage flags of the key.  The next typescript shows
       how to add the encryption subkey:

         $ gpg --edit-key 7F899AE2FB73159DD68A1B20C3AFA9ED971BB365
         Secret key is available.

         sec  rsa2048/C3AFA9ED971BB365
              created: 2019-04-04  expires: never       usage: SC
              card-no: FF020001008A77C1
              trust: ultimate      validity: ultimate
         [ultimate] (1). otto@example.net
         gpg> addkey
         Secret parts of primary key are stored on-card.
         Please select what kind of key you want:
            (3) DSA (sign only)
            (4) RSA (sign only)
            (5) Elgamal (encrypt only)
            (6) RSA (encrypt only)
           (14) Existing key from card
         Your selection? 14
         Serial number of the card: FF020001008A77C1
         Available keys:
            (1) 213D1825FDE0F8240CB4E4229F01AF90AC658C2E PIV.9A nistp384 (auth)
            (2) 7A53E6CFFE7220A0E646B4632EE29E5A7104499C PIV.9E nistp256 (auth)
            (3) 32A6C6FAFCB8421878608AAB452D5470DD3223ED PIV.9C rsa2048 (cert,sign)
            (4) 34798AAFE0A7565088101CC4AE31C5C8C74461CB PIV.9D rsa2048 (encr)
         Your selection? 4
         Please specify how long the key should be valid.
                  0 = key does not expire
               <n>  = key expires in n days
               <n>w = key expires in n weeks
               <n>m = key expires in n months
               <n>y = key expires in n years
         Key is valid for? (0)
         Key does not expire at all
         Is this correct? (y/N) y
         Really create? (y/N) y

         sec  rsa2048/C3AFA9ED971BB365
              created: 2019-04-04  expires: never       usage: SC
              card-no: FF020001008A77C1
              trust: ultimate      validity: ultimate
         ssb  rsa2048/7067860A98FCE6E1
              created: 2019-04-04  expires: never       usage: E
              card-no: FF020001008A77C1
         [ultimate] (1). otto@example.net

         gpg> save

       Now you can use your PIV card also with gpg.




OPTIONS

       gpg-card understands these options:



       --with-colons
              This option has currently no effect.


       --status-fd n
              Write special status strings to the file descriptor n.  This
              program returns only the status messages SUCCESS or FAILURE
              which are helpful when the caller uses a double fork approach
              and can't easily get the return code of the process.


       --verbose
              Enable extra informational output.


       --quiet
              Disable almost all informational output.


       --version
              Print version of the program and exit.


       --help Display a brief help page and exit.


       --no-autostart
              Do not start the gpg-agent if it has not yet been started and
              its service is required.  This option is mostly useful on
              machines where the connection to gpg-agent has been redirected
              to another machines.


       --no-history
              In interactive mode the command line history is usually saved
              and restored to and from a file below the GnuPG home directory.
              This option inhibits the use of that file.


       --agent-program file
              Specify the agent program to be started if none is running.  The
              default value is determined by running gpgconf with the option
              --list-dirs.


       --gpg-program file
              Specify a non-default gpg binary to be used by certain commands.


       --gpgsm-program file
              Specify a non-default gpgsm binary to be used by certain
              commands.


       --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-card
              for another 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 effect at all on Windows.



SEE ALSO

       scdaemon(1)

GnuPG 2.5.16                      2025-12-29                       gpg-card(1)

gnupg 2.5.16 - Generated Sun Jan 18 06:08:20 CST 2026
© manpagez.com 2000-2026
Individual documents may contain additional copyright information.