1.\" Copyright (c) 2020 Yubico AB. All rights reserved. 2.\" Use of this source code is governed by a BSD-style 3.\" license that can be found in the LICENSE file. 4.\" 5.Dd $Mdocdate: August 5 2020 $ 6.Dt FIDO_DEV_GET_TOUCH_BEGIN 3 7.Os 8.Sh NAME 9.Nm fido_dev_get_touch_begin , 10.Nm fido_dev_get_touch_status 11.Nd asynchronously wait for touch on a FIDO 2 authenticator 12.Sh SYNOPSIS 13.In fido.h 14.Ft int 15.Fn fido_dev_get_touch_begin "fido_dev_t *dev" 16.Ft int 17.Fn fido_dev_get_touch_status "fido_dev_t *dev" "int *touched" "int ms" 18.Sh DESCRIPTION 19The functions described in this page allow an application to 20asynchronously wait for touch on a FIDO authenticator. 21This is useful when multiple authenticators are present and 22the application needs to know which one to use. 23.Pp 24The 25.Fn fido_dev_get_touch_begin 26function initiates a touch request on 27.Fa dev . 28.Pp 29The 30.Fn fido_dev_get_touch_status 31function continues an ongoing touch request on 32.Fa dev , 33blocking up to 34.Fa ms 35milliseconds. 36On success, 37.Fa touched 38will be updated to reflect the touch request status. 39If 40.Fa touched 41is 1, the device was touched, and the touch request is 42terminated. 43If 44.Fa touched 45is 0, the application may call 46.Fn fido_dev_get_touch_status 47to continue the touch request, or 48.Fn fido_dev_cancel 49to terminate it. 50.Sh RETURN VALUES 51The error codes returned by 52.Fn fido_dev_get_touch_begin 53and 54.Fn fido_dev_get_touch_status 55are defined in 56.In fido/err.h . 57On success, 58.Dv FIDO_OK 59is returned. 60.Sh EXAMPLES 61Please refer to 62.Em examples/select.c 63in 64.Em libfido2's 65source tree. 66.Sh SEE ALSO 67.Xr fido_dev_cancel 3 68.Sh CAVEATS 69The 70.Fn fido_dev_get_touch_status 71function will cause a command to be transmitted to U2F 72authenticators. 73These transmissions should not exceed a frequency of 5Hz. 74