@c Copyright (C) 2002 Free Software Foundation, Inc. @c This is part of the GnuPG manual. @c For copying conditions, see the file gnupg.texi. @include defs.inc @node Invoking SCDAEMON @chapter Invoking the SCDAEMON @cindex SCDAEMON command options @cindex command options @cindex options, SCDAEMON command @manpage scdaemon.1 @ifset manverb .B scdaemon \- Smartcard daemon for the GnuPG system @end ifset @mansect synopsis @ifset manverb .B scdaemon .RB [ \-\-homedir .IR dir ] .RB [ \-\-options .IR file ] .RI [ options ] .B \-\-server .br .B scdaemon .RB [ \-\-homedir .IR dir ] .RB [ \-\-options .IR file ] .RI [ options ] .B \-\-daemon .RI [ command_line ] @end ifset @mansect description The @command{scdaemon} is a daemon to manage smartcards. It is usually invoked by @command{gpg-agent} and in general not used directly. @manpause @xref{Option Index}, for an index to @command{scdaemon}'s commands and options. @mancont @menu * Scdaemon Commands:: List of all commands. * Scdaemon Options:: List of all options. * Card applications:: Description of card applications. * Scdaemon Configuration:: Configuration files. * Scdaemon Examples:: Some usage examples. * Scdaemon Protocol:: The protocol the daemon uses. @end menu @mansect commands @node Scdaemon Commands @section Commands Commands are not distinguished from options except for the fact that only one command is allowed. @table @gnupgtabopt @item --version @opindex version Print the program version and licensing information. Note that you cannot abbreviate this command. @item --help, -h @opindex help Print a usage message summarizing the most useful command-line options. Note that you can abbreviate this command. @item --dump-options @opindex dump-options Print a list of all available options and commands. Note that you cannot abbreviate this command. @item --server @opindex server Run in server mode and wait for commands on the @code{stdin}. The default mode is to create a socket and listen for commands there. @item --multi-server @opindex multi-server Run in server mode and wait for commands on the @code{stdin} as well as on an additional Unix Domain socket. The server command @code{GETINFO} may be used to get the name of that extra socket. @item --daemon @opindex daemon Run the program in the background. This option is required to prevent it from being accidentally running in the background. @end table @mansect options @node Scdaemon Options @section Option Summary @table @gnupgtabopt @item --options @var{file} @opindex options Reads configuration from @var{file} instead of from the default per-user configuration file. The default configuration file is named @file{scdaemon.conf} and expected in the @file{.gnupg} directory directly below the home directory of the user. @include opt-homedir.texi @item -v @item --verbose @opindex v @opindex verbose Outputs additional information while running. You can increase the verbosity by giving several verbose commands to @command{gpgsm}, such as @samp{-vv}. @item --debug-level @var{level} @opindex debug-level Select the debug level for investigating problems. @var{level} may be a numeric value or a keyword: @table @code @item none No debugging at all. A value of less than 1 may be used instead of the keyword. @item basic Some basic debug messages. A value between 1 and 2 may be used instead of the keyword. @item advanced More verbose debug messages. A value between 3 and 5 may be used instead of the keyword. @item expert Even more detailed messages. A value between 6 and 8 may be used instead of the keyword. @item 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. @end table How these messages are mapped to the actual debugging flags is not specified and may change with newer releases of this program. They are however carefully selected to best aid in debugging. @quotation Note All debugging options are subject to change and thus should not be used by any application program. As the name says, they are only used as helpers to debug problems. @end quotation @item --debug @var{flags} @opindex debug This option is only useful for debugging and the behavior may change at any time without notice. FLAGS are bit encoded and may be given in usual C-Syntax. The currently defined bits are: @table @code @item 0 (1) command I/O @item 1 (2) values of big number integers @item 2 (4) low level crypto operations @item 5 (32) memory allocation @item 6 (64) caching @item 7 (128) show memory statistics @item 9 (512) write hashed data to files named @code{dbgmd-000*} @item 10 (1024) trace Assuan protocol. See also option @option{--debug-assuan-log-cats}. @item 11 (2048) trace APDU I/O to the card. This may reveal sensitive data. @item 12 (4096) trace some card reader related function calls. @end table @item --debug-all @opindex debug-all Same as @code{--debug=0xffffffff} @item --debug-wait @var{n} @opindex debug-wait When running in server mode, wait @var{n} seconds before entering the actual processing loop and print the pid. This gives time to attach a debugger. @item --debug-ccid-driver @opindex debug-wait Enable debug output from the included CCID driver for smartcards. Using this option twice will also enable some tracing of the T=1 protocol. Note that this option may reveal sensitive data. @item --debug-disable-ticker @opindex debug-disable-ticker This option disables all ticker functions like checking for card insertions. @item --debug-allow-core-dump @opindex debug-allow-core-dump For security reasons we won't create a core dump when the process aborts. For debugging purposes it is sometimes better to allow core dump. This option enables it and also changes the working directory to @file{/tmp} when running in @option{--server} mode. @item --debug-log-tid @opindex debug-log-tid This option appends a thread ID to the PID in the log output. @item --debug-assuan-log-cats @var{cats} @opindex debug-assuan-log-cats @efindex ASSUAN_DEBUG Changes the active Libassuan logging categories to @var{cats}. The value for @var{cats} is an unsigned integer given in usual C-Syntax. A value of of 0 switches to a default category. If this option is not used the categories are taken from the environment variable @code{ASSUAN_DEBUG}. Note that this option has only an effect if the Assuan debug flag has also been with the option @option{--debug}. For a list of categories see the Libassuan manual. @item --no-detach @opindex no-detach Don't detach the process from the console. This is mainly useful for debugging. @item --log-file @var{file} @opindex log-file Append all logging output to @var{file}. This is very helpful in seeing what the agent actually does. Use @file{socket://} to log to socket. @item --pcsc-driver @var{library} @opindex pcsc-driver Use @var{library} to access the smartcard reader. The current default is @file{libpcsclite.so}. Instead of using this option you might also want to install a symbolic link to the default file name (e.g. from @file{libpcsclite.so.1}). @item --ctapi-driver @var{library} @opindex ctapi-driver Use @var{library} to access the smartcard reader. The current default is @file{libtowitoko.so}. Note that the use of this interface is deprecated; it may be removed in future releases. @item --disable-ccid @opindex disable-ccid Disable the integrated support for CCID compliant readers. This allows falling back to one of the other drivers even if the internal CCID driver can handle the reader. Note, that CCID support is only available if libusb was available at build time. @item --reader-port @var{number_or_string} @opindex reader-port This option may be used to specify the port of the card terminal. A value of 0 refers to the first serial device; add 32768 to access USB devices. The default is 32768 (first USB device). PC/SC or CCID readers might need a string here; run the program in verbose mode to get a list of available readers. The default is then the first reader found. To get a list of available CCID readers you may use this command: @cartouche @smallexample echo scd getinfo reader_list \ | gpg-connect-agent --decode | awk '/^D/ @{print $2@}' @end smallexample @end cartouche @item --card-timeout @var{n} @opindex card-timeout If @var{n} is not 0 and no client is actively using the card, the card will be powered down after @var{n} seconds. Powering down the card avoids a potential risk of damaging a card when used with certain cheap readers. This also allows applications that are not aware of Scdaemon to access the card. The disadvantage of using a card timeout is that accessing the card takes longer and that the user needs to enter the PIN again after the next power up. Note that with the current version of Scdaemon the card is powered down immediately at the next timer tick for any value of @var{n} other than 0. @item --enable-pinpad-varlen @opindex enable-pinpad-varlen Please specify this option when the card reader supports variable length input for pinpad (default is no). For known readers (listed in ccid-driver.c and apdu.c), this option is not needed. Note that if your card reader doesn't supports variable length input but you want to use it, you need to specify your pinpad request on your card. @item --disable-pinpad @opindex disable-pinpad Even if a card reader features a pinpad, do not try to use it. @item --deny-admin @opindex deny-admin @opindex allow-admin This option disables the use of admin class commands for card applications where this is supported. Currently we support it for the OpenPGP card. This option is useful to inhibit accidental access to admin class command which could ultimately lock the card through wrong PIN numbers. Note that GnuPG versions older than 2.0.11 featured an @option{--allow-admin} option which was required to use such admin commands. This option has no more effect today because the default is now to allow admin commands. @item --disable-application @var{name} @opindex disable-application This option disables the use of the card application named @var{name}. This is mainly useful for debugging or if a application with lower priority should be used by default. @end table All the long options may also be given in the configuration file after stripping off the two leading dashes. @mansect card applications @node Card applications @section Description of card applications @command{scdaemon} supports the card applications as described below. @menu * OpenPGP Card:: The OpenPGP card application * NKS Card:: The Telesec NetKey card application * DINSIG Card:: The DINSIG card application * PKCS#15 Card:: The PKCS#15 card application * Geldkarte Card:: The Geldkarte application * SmartCard-HSM:: The SmartCard-HSM application * Undefined Card:: The Undefined stub application @end menu @node OpenPGP Card @subsection The OpenPGP card application ``openpgp'' This application is currently only used by @command{gpg} but may in future also be useful with @command{gpgsm}. Version 1 and version 2 of the card is supported. @noindent The specifications for these cards are available at@* @uref{http://g10code.com/docs/openpgp-card-1.0.pdf} and@* @uref{http://g10code.com/docs/openpgp-card-2.0.pdf}. @node NKS Card @subsection The Telesec NetKey card ``nks'' This is the main application of the Telesec cards as available in Germany. It is a superset of the German DINSIG card. The card is used by @command{gpgsm}. @node DINSIG Card @subsection The DINSIG card application ``dinsig'' This is an application as described in the German draft standard @emph{DIN V 66291-1}. It is intended to be used by cards supporting the German signature law and its bylaws (SigG and SigV). @node PKCS#15 Card @subsection The PKCS#15 card application ``p15'' This is common framework for smart card applications. It is used by @command{gpgsm}. @node Geldkarte Card @subsection The Geldkarte card application ``geldkarte'' This is a simple application to display information of a German Geldkarte. The Geldkarte is a small amount debit card application which comes with almost all German banking cards. @node SmartCard-HSM @subsection The SmartCard-HSM card application ``sc-hsm'' This application adds read-only support for keys and certificates stored on a @uref{http://www.smartcard-hsm.com, SmartCard-HSM}. To generate keys and store certifiates you may use @uref{https://github.com/OpenSC/OpenSC/wiki/SmartCardHSM, OpenSC} or the tools from @uref{http://www.openscdp.org, OpenSCDP}. The SmartCard-HSM cards requires a card reader that supports Extended Length APDUs. @node Undefined Card @subsection The Undefined card application ``undefined'' This is a stub application to allow the use of the APDU command even if no supported application is found on the card. This application is not used automatically but must be explicitly requested using the SERIALNO command. @c ******************************************* @c *************** **************** @c *************** FILES **************** @c *************** **************** @c ******************************************* @mansect files @node Scdaemon Configuration @section Configuration files There are a few configuration files to control certain aspects of @command{scdaemons}'s operation. Unless noted, they are expected in the current home directory (@pxref{option --homedir}). @table @file @item scdaemon.conf @cindex scdaemon.conf This is the standard configuration file read by @command{scdaemon} on startup. It may contain any valid long option; the leading two dashes may not be entered and the option may not be abbreviated. This default name may be changed on the command line (@pxref{option --options}). @item scd-event @cindex scd-event If this file is present and executable, it will be called on every card reader's status change. An example of this script is provided with the distribution @item reader_@var{n}.status This file is created by @command{scdaemon} to let other applications now about reader status changes. Its use is now deprecated in favor of @file{scd-event}. @end table @c @c Examples @c @mansect examples @node Scdaemon Examples @section Examples @c man begin EXAMPLES @example $ scdaemon --server -v @end example @c man end @c @c Assuan Protocol @c @manpause @node Scdaemon Protocol @section 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 @file{@value{LOCALRUNDIR}/scdaemon/socket}, configuration information is read from @var{@value{SYSCONFDIR}/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 @end menu @node Scdaemon SERIALNO @subsection Return the serial number This command should be used to check for the presence of a card. It is special in that it can be used to reset the card. Most other commands will return an error when a card change has been detected and the use of this function is therefore required. Background: We want to keep the client clear of handling card changes between operations; i.e. the client can assume that all operations are done on the same card unless he call this function. @example SERIALNO @end example Return the serial number of the card using a status response like: @example S SERIALNO D27600000000000000000000 0 @end example The trailing 0 should be ignored for now, it is reserved for a future extension. The serial number is the hex encoded value identified by the @code{0x5A} tag in the GDO file (FIX=0x2F02). @node Scdaemon LEARN @subsection Read all useful information from the card @example LEARN [--force] @end example Learn all useful information of the currently inserted card. When used without the @option{--force} option, the command might do an INQUIRE like this: @example INQUIRE KNOWNCARDP @end example The client should just send an @code{END} if the processing should go on or a @code{CANCEL} to force the function to terminate with a cancel error message. The response of this command is a list of status lines formatted as this: @example S KEYPAIRINFO @var{hexstring_with_keygrip} @var{hexstring_with_id} @end example If there is no certificate yet stored on the card a single "X" is returned in @var{hexstring_with_keygrip}. @node Scdaemon READCERT @subsection Return a certificate @example READCERT @var{hexified_certid}|@var{keyid} @end example This function is used to read a certificate identified by @var{hexified_certid} from the card. With OpenPGP cards the keyid @code{OpenPGP.3} may be used to read the certificate of version 2 cards. @node Scdaemon READKEY @subsection Return a public key @example READKEY @var{hexified_certid} @end example Return the public key for the given cert or key ID as an standard S-Expression. @node Scdaemon PKSIGN @subsection Signing data with a Smartcard To sign some data the caller should use the command @example SETDATA @var{hexstring} @end example to tell @command{scdaemon} about the data to be signed. The data must be given in hex notation. The actual signing is done using the command @example PKSIGN @var{keyid} @end example where @var{keyid} is the hexified ID of the key to be used. The key id may have been retrieved using the command @code{LEARN}. If another hash algorithm than SHA-1 is used, that algorithm may be given like: @example PKSIGN --hash=@var{algoname} @var{keyid} @end example With @var{algoname} are one of @code{sha1}, @code{rmd160} or @code{md5}. @node Scdaemon PKDECRYPT @subsection Decrypting data with a Smartcard To decrypt some data the caller should use the command @example SETDATA @var{hexstring} @end example to tell @command{scdaemon} about the data to be decrypted. The data must be given in hex notation. The actual decryption is then done using the command @example PKDECRYPT @var{keyid} @end example where @var{keyid} is the hexified ID of the key to be used. If the card is aware of the apdding format a status line with padding information is send before the plaintext data. The key for this status line is @code{PADDING} with the only defined value being 0 and meaning padding has been removed. @node Scdaemon GETATTR @subsection Read an attribute's value. TO BE WRITTEN. @node Scdaemon SETATTR @subsection Update an attribute's value. TO BE WRITTEN. @node Scdaemon WRITEKEY @subsection Write a key to a card. @example WRITEKEY [--force] @var{keyid} @end example This command is used to store a secret key on a smartcard. The allowed keyids depend on the currently selected smartcard application. The actual keydata is requested using the inquiry @code{KEYDATA} and need to be provided without any protection. With @option{--force} set an existing key under this @var{keyid} will get overwritten. The key data is expected to be the usual canonical encoded S-expression. A PIN will be requested in most cases. This however depends on the actual card application. @node Scdaemon GENKEY @subsection Generate a new key on-card. TO BE WRITTEN. @node Scdaemon RANDOM @subsection Return random bytes generate on-card. TO BE WRITTEN. @node Scdaemon PASSWD @subsection Change PINs. @example PASSWD [--reset] [--nullpin] @var{chvno} @end example Change the PIN or reset the retry counter of the card holder verification vector number @var{chvno}. The option @option{--nullpin} is used to initialize the PIN of TCOS cards (6 byte NullPIN only). @node Scdaemon CHECKPIN @subsection Perform a VERIFY operation. @example CHECKPIN @var{idstr} @end example Perform a VERIFY operation without doing anything else. This may be used to initialize a the PIN cache earlier to long lasting operations. Its use is highly application dependent: @table @strong @item OpenPGP Perform a simple verify operation for CHV1 and CHV2, so that further operations won't ask for CHV2 and it is possible to do a cheap check on the PIN: If there is something wrong with the PIN entry system, only the regular CHV will get blocked and not the dangerous CHV3. @var{idstr} is the usual card's serial number in hex notation; an optional fingerprint part will get ignored. There is however a special mode if @var{idstr} is suffixed with the literal string @code{[CHV3]}: In this case the Admin PIN is checked if and only if the retry counter is still at 3. @end table @node Scdaemon RESTART @subsection Perform a RESTART operation. @example RESTART @end example Restart the current connection; this is a kind of warm reset. It deletes the context used by this connection but does not actually reset the card. This is used by gpg-agent to reuse a primary pipe connection and may be used by clients to backup from a conflict in the serial command; i.e. to select another application. @node Scdaemon APDU @subsection Send a verbatim APDU to the card. @example APDU [--atr] [--more] [--exlen[=@var{n}]] [@var{hexstring}] @end example Send an APDU to the current reader. This command bypasses the high level functions and sends the data directly to the card. @var{hexstring} is expected to be a proper APDU. If @var{hexstring} is not given no commands are send to the card; However the command will implicitly check whether the card is ready for use. Using the option @code{--atr} returns the ATR of the card as a status message before any data like this: @example S CARD-ATR 3BFA1300FF813180450031C173C00100009000B1 @end example Using the option @code{--more} handles the card status word MORE_DATA (61xx) and concatenate all responses to one block. Using the option @code{--exlen} the returned APDU may use extended length up to N bytes. If N is not given a default value is used (currently 4096). @mansect see also @ifset isman @command{gpg-agent}(1), @command{gpgsm}(1), @command{gpg2}(1) @end ifset @include see-also-note.texi