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NAME

     gnupg-pkcs11-scd - GnuPG-compatible smart-card daemon with PKCS#11
     support

SYNOPSIS

     gnupg-pkcs11-scd [--server] [--multi-server] [--daemon] [--verbose]
                      [--quiet] [--sh] [--csh] [--options file] [--no-detach]
                      [--log-file file] [--help]

DESCRIPTION

     gnupg-pkcs11-scd is a drop-in replacement for the smart-card daemon (scd)
     shipped with the next-generation GnuPG (gnupg-2). The daemon interfaces
     to smart-cards by using RSA Security Inc. PKCS#11 Cryptographic Token
     Interface (Cryptoki).  The following options are available:

     --server
         Run in server mode (foreground). If not redirected, input and output
         are over stdin/stdout.

     --multi-server
         Run in multi-server mode (foreground). In addition to communicating
         over stdin/stdout, the server also opens an additional listening UNIX
         socket.

     --daemon
         Detach and run in background.

     --verbose
         Be verbose while running.

     --quiet
         Be as quiet as possible.

     --sh
         Output sh-style environment variable definition.

     --csh
         Output csh-style environment variable definition.

     --options file
         Read options from file.  Some of the configuration options can only
         be set in the configuration file (see the CONFIGURATION section).

     --no-detach
         Do not detach from console (useful for debugging purposes).

     --log-file file
         Output log to file.

     --help
         Print help information.

     When the daemon receives any of the SIGHUP, SIGTERM and SIGINT signals,
     it cleans up and exits.

     gnupg-pkcs11-scd works only with already personalized cards, and supports
     (for the time being) only RSA keypairs.  The following constraints must
     be satisfied:

     1.   For each private key object, a certificate object must exist on the
          card.  The existence of the corresponding public key object is not
          important (since the certificate includes public key).
     2.   The certificate and the corresponding private key must have
          identical CKA_ID attribute.

     The PKCS#11 implementation is not obliged to enforce any of the above
     rules.  However, practice has shown that popular PKCS#11 implementations
     found "in the wild" seem to respect them.

NOTES

     Unlike gpg-agent, gnupg-pkcs11-scd supports more than one token available
     at the same time. In order to make gpg-agent happy, gnupg-pkcs11-scd
     always returns the same card serial number to gpg-agent.  When
     unavailable token is requested, gnupg-pkcs11-scd will use NEEDPIN
     callback in order to ask for the requested token.  When and if gpg-agent
     will support more than one serial number or NEEDTOKEN callback, this
     behavior will be modified.

ENVIRONMENT

     HOME         Used to locate the home directory.
     GNUPGHOME    Used instead of ~/.gnupg.
     USERPROFILE  Used only on Win32 to locate the home directory.

     Additionally, the \\Software\\GNU\\GnuPG\\HomeDir registry key is used on
     Win32 to locate the default GNUPGHOME.

FILES

     Files affecting the operation of gnupg-pkcs11-scd:

     ~/.gnupg/gnupg-pkcs11-scd.conf    gnupg-pkcs11-scd uses this as a default
                                       configuration file.

     /etc/gnupg-pkcs11-scd.conf        gnupg-pkcs11-scd uses this as a default
                                       system wide configuration file.

     ~/.gnupg/gpg-agent.conf           Default configuration file for gpg-
                                       agent.

CONFIGURATION

     To tell gpg-agent to use another smart-card daemon, the following needs
     to be put in ~/.gnupg/gpg-agent.conf:

           scdaemon-program /usr/bin/gnupg-pkcs11-scd
           pinentry-program /usr/bin/pinentry-qt

     The first line is mandatory in order to use gnupg-pkcs11-scd.  With the
     second line you can set your preferred pinentry program (it has to be one
     compatible with GnuPG). Of course, you need to adjust the paths according
     to your system setup.

     An example ~/.gnupg/gnupg-pkcs11-scd.conf file (lines beginning with #
     are comments):

           # Log file.
           #log-file log1

           # Default is not verbose.
           #verbose

           # Default is no debugging.
           #debug-all

           # Pin cache period in seconds; default is infinite.
           #pin-cache 20

           # Comma-separated list of available provider names. Then set
           # attributes for each provider using the provider-[name]-attribute
           # syntax.
           providers p1

           # Provider attributes (see below for detailed description)
           provider-p1-library /usr/lib/pkcs11/p1.so
           #provider-p1-allow-protected-auth
           #provider-p1-cert-private
           #provider-p1-private-mask 0

           #emulate-openpgpg
           #openpgp-sign 5C661B8C07CFD957F7D98D5B9A0F31D236BFAC2A
           #openpgp-encr D2DC0BD1EDD185969748B6025B452816F97CBA57
           #openpgp-auth A7B8C1A3A8F71FCEC018886F8767927B9C8D871F

     The following attributes can be set for each provider:

     library
         Full path to the PKCS#11 shared library (= provider).

     allow-protected-auth
         Allow protected authentication for provider. This needs to be
         supported by the provider and you should have appropriate reader
         hardware.

     cert-private
         Authentication is required before certificates can be accessed. Most
         configurations store certificates as public, so there is no need to
         use this option.

     private-mask
         Private key mask mode. Use this only when you have problem using
         private key operations. The value is hex encoded mask number.
         0        Determine automatically.
         1        Force sign.
         2        Force sign with recovery.
         4        Force decrypt.
         8        Force decrypt with unwrap.

     emulate-openpgp
         Emulate OpenPGP card. Unfortunately, gnupg cannot handle the OpenPGP
         card with certificates.  So you need to turn this on in order to
         learn card keys.

         In OpenPGP card emulation we cannot guess which key should match a
         type, so you have to specify the SHA1 of the key explicitly.

         In order to determine which key is which, use the following command:
               gpg-agent --server gpg-connect-agent
         Enter "SCD LEARN" and look for "KEY-FRIEDNLY" responses, the first
         field is the hash, the second is the subject name.

         You still have to store a certificate (may be self-signed) that
         corresponds to the keypair.

     openpgp-sign
         Hex string (Upper letter, no space) SHA1 of signing public key.

     openpgp-encr
         Hex string (Upper letter, no space) SHA1 of encryption public key.

     openpgp-auth
         Hex string (Upper letter, no space) SHA1 of authentication public
         key.

GNUPG INTEGRATION

     Typical steps to set up a card for gpgsm usage:

     1.   Import the CA certificate of your issuer:
                gpgsm --import < ca-certificate
          You should also manually import all self-signed certificates.

     2.   Instruct GnuPG to discover all useful certificates on the card:
                gpgsm --learn-card

     Signing, verification, etc. work as usual with gpgsm.

     Typical steps to set up a card for gpg usage:

     1.   Configure gnupg-pkcs11-scd for opengpg emulation, specify the public
          key hashes to be used for signature, encryption and authentication.

     2.   Instruct GnuPG to discover all useful information of card:
                gpg --card-status
          You should see valid card status.

     3.   Now, you should virtual generate keys, the keys are not actually
          generated, but returned to gpg to be registered.
                gpg --card-edit
                admin
                generate (DO NOT BACKUP KEYS)

     4.   Disable the opengpg emulation.

     Now you can use the same card with your gpg and gpgsm keys. We don’t know
     if this is a bug or feature in gnupg, but we glad that it works.

     Signing, verification, etc. work as usual with gpg.

SECURITY CONSIDERATIONS

     All communication between components is currently unprotected and in
     plain text (that’s how the Assuan protocol operates). It is trivial to
     trace (using e.g. the strace(1) program) individual components (e.g.
     pinentry) and steal sensitive data (such as the smart-card PIN) or even
     change it (e.g. the hash to be signed).

     When using the software in production scenario, be sure to turn off
     debugging/verbose options in configuration of all components. Otherwise,
     some sensitive data might be displayed on the screen (most notably, the
     PIN).

SEE ALSO

     strace(1) truss(1) gnupg(7)

     GnuPG Home Page, http://www.gnupg.org.

     gnupg-pkcs11 Home Page, http://gnupg-pkcs11.sourceforge.net.

AUTHORS AND COPYRIGHT

     Copyright (c) 2006-2007 Zeljko Vrba <zvrba@globalnet.hr>

     Copyright (c) 2006-2007 Alon Bar-Lev <alon.barlev@gmail.com>

     All rights reserved.

     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
     OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
     IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
     CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT
     OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR
     THE USE OR OTHER DEALINGS IN THE SOFTWARE.