NAME

       fido_dev_get_touch_begin,   fido_dev_get_touch_status   —  asynchronously  wait  for  touch  on  a  FIDO2
       authenticator

SYNOPSIS

       #include <fido.h>

       int
       fido_dev_get_touch_begin(fido_dev_t *dev);

       int
       fido_dev_get_touch_status(fido_dev_t *dev, int *touched, int ms);

DESCRIPTION

       The functions described in this page allow an application to asynchronously wait for  touch  on  a  FIDO2
       authenticator.  This is useful when multiple authenticators are present and the application needs to know
       which one to use.

       The fido_dev_get_touch_begin() function initiates a touch request on dev.

       The  fido_dev_get_touch_status()  function  continues  an ongoing touch request on dev, blocking up to ms
       milliseconds.  On success, touched will be updated to reflect the touch request status.  If touched is 1,
       the device was touched, and the touch request is terminated.  If touched is 0, the application  may  call
       fido_dev_get_touch_status() to continue the touch request, or fido_dev_cancel() to terminate it.

RETURN VALUES

       The  error  codes  returned  by fido_dev_get_touch_begin() and fido_dev_get_touch_status() are defined in
       <fido/err.h>.  On success, FIDO_OK is returned.

EXAMPLES

       Please refer to examples/select.c in libfido2's source tree.

SEE ALSO

       fido_dev_cancel(3)

CAVEATS

       The fido_dev_get_touch_status() function will cause a command to be transmitted  to  U2F  authenticators.
       These transmissions should not exceed a frequency of 5Hz.

Debian                                           August 5, 2020                      FIDO_DEV_GET_TOUCH_BEGIN(3)