.\" Copyright (c) 2018 Yubico AB. All rights reserved.
.\" Use of this source code is governed by a BSD-style
.\" license that can be found in the LICENSE file.
.\"
.Dd $Mdocdate: August 29 2022 $
.Dt FIDO_DEV_OPEN 3
.Os
.Sh NAME
.Nm fido_dev_open ,
.Nm fido_dev_open_with_info ,
.Nm fido_dev_close ,
.Nm fido_dev_cancel ,
.Nm fido_dev_new ,
.Nm fido_dev_new_with_info ,
.Nm fido_dev_free ,
.Nm fido_dev_force_fido2 ,
.Nm fido_dev_force_u2f ,
.Nm fido_dev_is_fido2 ,
.Nm fido_dev_is_winhello ,
.Nm fido_dev_supports_credman ,
.Nm fido_dev_supports_cred_prot ,
.Nm fido_dev_supports_permissions ,
.Nm fido_dev_supports_pin ,
.Nm fido_dev_supports_uv ,
.Nm fido_dev_has_pin ,
.Nm fido_dev_has_uv ,
.Nm fido_dev_protocol ,
.Nm fido_dev_build ,
.Nm fido_dev_flags ,
.Nm fido_dev_major ,
.Nm fido_dev_minor
.Nd FIDO2 device open/close and related functions
.Sh SYNOPSIS
.In fido.h
.Ft int
.Fn fido_dev_open "fido_dev_t *dev" "const char *path"
.Ft int
.Fn fido_dev_open_with_info "fido_dev_t *dev"
.Ft int
.Fn fido_dev_close "fido_dev_t *dev"
.Ft int
.Fn fido_dev_cancel "fido_dev_t *dev"
.Ft fido_dev_t *
.Fn fido_dev_new "void"
.Ft fido_dev_t *
.Fn fido_dev_new_with_info "const fido_dev_info_t *"
.Ft void
.Fn fido_dev_free "fido_dev_t **dev_p"
.Ft void
.Fn fido_dev_force_fido2 "fido_dev_t *dev"
.Ft void
.Fn fido_dev_force_u2f "fido_dev_t *dev"
.Ft bool
.Fn fido_dev_is_fido2 "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_is_winhello "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_supports_credman "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_supports_cred_prot "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_supports_permissions "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_supports_pin "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_supports_uv "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_has_pin "const fido_dev_t *dev"
.Ft bool
.Fn fido_dev_has_uv "const fido_dev_t *dev"
.Ft uint8_t
.Fn fido_dev_protocol "const fido_dev_t *dev"
.Ft uint8_t
.Fn fido_dev_build "const fido_dev_t *dev"
.Ft uint8_t
.Fn fido_dev_flags "const fido_dev_t *dev"
.Ft uint8_t
.Fn fido_dev_major "const fido_dev_t *dev"
.Ft uint8_t
.Fn fido_dev_minor "const fido_dev_t *dev"
.Sh DESCRIPTION
The
.Fn fido_dev_open
function opens the device pointed to by
.Fa path ,
where
.Fa dev
is a freshly allocated or otherwise closed
.Vt fido_dev_t .
If
.Fa dev
claims to be FIDO2,
.Em libfido2
will attempt to speak FIDO2 to
.Fa dev .
If that fails,
.Em libfido2
will fallback to U2F unless the
.Dv FIDO_DISABLE_U2F_FALLBACK
flag was set in
.Xr fido_init 3 .
.Pp
The
.Fn fido_dev_open_with_info
function opens
.Fa dev
as previously allocated using
.Fn fido_dev_new_with_info .
.Pp
The
.Fn fido_dev_close
function closes the device represented by
.Fa dev .
If
.Fa dev
is already closed,
.Fn fido_dev_close
is a NOP.
.Pp
The
.Fn fido_dev_cancel
function cancels any pending requests on
.Fa dev .
.Pp
The
.Fn fido_dev_new
function returns a pointer to a newly allocated, empty
.Vt fido_dev_t .
If memory cannot be allocated, NULL is returned.
.Pp
The
.Fn fido_dev_new_with_info
function returns a pointer to a newly allocated
.Vt fido_dev_t
with
.Vt fido_dev_info_t
parameters, for use with
.Xr fido_dev_info_manifest 3
and
.Fn fido_dev_open_with_info .
If memory cannot be allocated, NULL is returned.
.Pp
The
.Fn fido_dev_free
function releases the memory backing
.Fa *dev_p ,
where
.Fa *dev_p
must have been previously allocated by
.Fn fido_dev_new .
On return,
.Fa *dev_p
is set to NULL.
Either
.Fa dev_p
or
.Fa *dev_p
may be NULL, in which case
.Fn fido_dev_free
is a NOP.
.Pp
The
.Fn fido_dev_force_fido2
function can be used to force CTAP2 communication with
.Fa dev ,
where
.Fa dev
is an open device.
.Pp
The
.Fn fido_dev_force_u2f
function can be used to force CTAP1 (U2F) communication with
.Fa dev ,
where
.Fa dev
is an open device.
.Pp
The
.Fn fido_dev_is_fido2
function returns
.Dv true
if
.Fa dev
is a FIDO2 device.
.Pp
The
.Fn fido_dev_is_winhello
function returns
.Dv true
if
.Fa dev
is a Windows Hello device.
.Pp
The
.Fn fido_dev_supports_credman
function returns
.Dv true
if
.Fa dev
supports CTAP 2.1 Credential Management.
.Pp
The
.Fn fido_dev_supports_cred_prot
function returns
.Dv true
if
.Fa dev
supports CTAP 2.1 Credential Protection.
.Pp
The
.Fn fido_dev_supports_permissions
function returns
.Dv true
if
.Fa dev
supports CTAP 2.1 UV token permissions.
.Pp
The
.Fn fido_dev_supports_pin
function returns
.Dv true
if
.Fa dev
supports CTAP 2.0 Client PINs.
.Pp
The
.Fn fido_dev_supports_uv
function returns
.Dv true
if
.Fa dev
supports a built-in user verification method.
.Pp
The
.Fn fido_dev_has_pin
function returns
.Dv true
if
.Fa dev
has a CTAP 2.0 Client PIN set.
.Pp
The
.Fn fido_dev_has_uv
function returns
.Dv true
if
.Fa dev
supports built-in user verification and its user verification
feature is configured.
.Pp
The
.Fn fido_dev_protocol
function returns the CTAPHID protocol version identifier of
.Fa dev .
.Pp
The
.Fn fido_dev_build
function returns the CTAPHID build version number of
.Fa dev .
.Pp
The
.Fn fido_dev_flags
function returns the CTAPHID capabilities flags of
.Fa dev .
.Pp
The
.Fn fido_dev_major
function returns the CTAPHID major version number of
.Fa dev .
.Pp
The
.Fn fido_dev_minor
function returns the CTAPHID minor version number of
.Fa dev .
.Pp
For the format and meaning of the CTAPHID parameters returned by
functions above, please refer to the FIDO Client to Authenticator
Protocol (CTAP) specification.
.Sh RETURN VALUES
On success,
.Fn fido_dev_open ,
.Fn fido_dev_open_with_info ,
and
.Fn fido_dev_close
return
.Dv FIDO_OK .
On error, a different error code defined in
.In fido/err.h
is returned.
.Sh SEE ALSO
.Xr fido_dev_info_manifest 3 ,
.Xr fido_dev_set_io_functions 3 ,
.Xr fido_init 3