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26.\" SPDX-License-Identifier: BSD-2-Clause
27.\"
28.Dd $Mdocdate: May 24 2018 $
29.Dt FIDO_DEV_GET_ASSERT 3
30.Os
31.Sh NAME
32.Nm fido_dev_get_assert
33.Nd obtains an assertion from a FIDO2 device
34.Sh SYNOPSIS
35.In fido.h
36.Ft int
37.Fn fido_dev_get_assert "fido_dev_t *dev" "fido_assert_t *assert" "const char *pin"
38.Sh DESCRIPTION
39The
40.Fn fido_dev_get_assert
41function asks the FIDO2 device represented by
42.Fa dev
43for an assertion according to the following parameters defined in
44.Fa assert :
45.Pp
46.Bl -dash -compact
47.It
48.Nm relying party ID ;
49.It
50.Nm client data hash ;
51.It
52.Nm list of allowed credential IDs ;
53.It
54.Nm user presence and user verification attributes .
55.El
56.Pp
57See
58.Xr fido_assert_set_authdata 3
59for information on how these values are set.
60.Pp
61If a PIN is not needed to authenticate the request against
62.Fa dev ,
63then
64.Fa pin
65may be NULL.
66Otherwise
67.Fa pin
68must point to a NUL-terminated UTF-8 string.
69.Pp
70After a successful call to
71.Fn fido_dev_get_assert ,
72the
73.Xr fido_assert_count 3 ,
74.Xr fido_assert_user_display_name 3 ,
75.Xr fido_assert_user_icon 3 ,
76.Xr fido_assert_user_name 3 ,
77.Xr fido_assert_authdata_ptr 3 ,
78.Xr fido_assert_user_id_ptr 3 ,
79.Xr fido_assert_sig_ptr 3 ,
80and
81.Xr fido_assert_sigcount 3
82functions may be invoked on
83.Fa assert
84to retrieve the various attributes of the generated assertion.
85.Pp
86Please note that
87.Fn fido_dev_get_assert
88is synchronous and will block if necessary.
89.Sh RETURN VALUES
90The error codes returned by
91.Fn fido_dev_get_assert
92are defined in
93.In fido/err.h .
94On success,
95.Dv FIDO_OK
96is returned.
97.Sh SEE ALSO
98.Xr fido_assert_new 3 ,
99.Xr fido_assert_set_authdata 3
100