File: gnupg.info,  Node: Scdaemon Protocol,  Prev: Scdaemon Examples,  Up: Invoking SCDAEMON

6.6 Scdaemon's Assuan Protocol
==============================

The SC-Daemon should be started by the system to provide access to
external tokens.  Using Smartcards on a multi-user system does not make
much sense except for system services, but in this case no regular user
accounts are hosted on the machine.

   A client connects to the SC-Daemon by connecting to the socket named
'/usr/local/var/run/gnupg/scdaemon/socket', configuration information is
read from /USR/LOCAL/ETC/GNUPG/SCDAEMON.CONF

   Each connection acts as one session, SC-Daemon takes care of
synchronizing access to a token between sessions.

* Menu:

* Scdaemon SERIALNO::     Return the serial number.
* Scdaemon LEARN::        Read all useful information from the card.
* Scdaemon READCERT::     Return a certificate.
* Scdaemon READKEY::      Return a public key.
* Scdaemon PKSIGN::       Signing data with a Smartcard.
* Scdaemon PKDECRYPT::    Decrypting data with a Smartcard.
* Scdaemon GETATTR::      Read an attribute's value.
* Scdaemon SETATTR::      Update an attribute's value.
* Scdaemon WRITEKEY::     Write a key to a card.
* Scdaemon GENKEY::       Generate a new key on-card.
* Scdaemon RANDOM::       Return random bytes generated on-card.
* Scdaemon PASSWD::       Change PINs.
* Scdaemon CHECKPIN::     Perform a VERIFY operation.
* Scdaemon RESTART::      Restart connection
* Scdaemon APDU::         Send a verbatim APDU to the card