fido_dev_enable_entattest, fido_dev_toggle_always_uv, fido_dev_force_pin_change, fido_dev_set_pin_minlen, fido_dev_set_pin_minlen_rpid
CTAP 2.1 configuration authenticator API

#include <fido.h>
#include <fido/config.h>
fido_dev_enable_entattest(fido_dev_t *dev, const char *pin);
fido_dev_toggle_always_uv(fido_dev_t *dev, const char *pin);
fido_dev_force_pin_change(fido_dev_t *dev, const char *pin);
fido_dev_set_pin_minlen(fido_dev_t *dev, size_t len, const char *pin);
fido_dev_set_pin_minlen_rpid(fido_dev_t *dev, const char * const *rpid, size_t n, const char *pin);

The functions described in this page allow configuration of a CTAP 2.1 authenticator.
The fido_dev_enable_entattest() function enables the Enterprise Attestation feature on dev. Enterprise Attestation instructs the authenticator to include uniquely identifying information in subsequent attestation statements. The pin parameter may be NULL if dev does not have a PIN set.
The fido_dev_toggle_always_uv() function toggles the “user verification always” feature on dev. When set, this toggle enforces user verification at the authenticator level for all known credentials. If dev supports U2F (CTAP1) and the user verification methods supported by the authenticator do not allow protection of U2F credentials, the U2F subsystem will be disabled by the authenticator. The pin parameter may be NULL if dev does not have a PIN set.
The fido_dev_force_pin_change() function instructs dev to require a PIN change. Subsequent PIN authentication attempts against dev will fail until its PIN is changed.
The fido_dev_set_pin_minlen() function sets the minimum PIN length of dev to len. Minimum PIN lengths may only be increased.
The fido_dev_set_pin_minlen_rpid() function sets the list of relying party identifiers (RP IDs) that are allowed to obtain the minimum PIN length of dev through the CTAP 2.1 FIDO_EXT_MINPINLEN extension. The list of RP identifiers is denoted by rpid, a vector of n NUL-terminated UTF-8 strings. A copy of rpid is made, and no reference to it or its contents is kept. The maximum value of n supported by the authenticator can be obtained using fido_cbor_info_maxrpid_minpinlen(3).
Configuration settings are reflected in the payload returned by the authenticator in response to a fido_dev_get_cbor_info(3) call.

The error codes returned by fido_dev_enable_entattest(), fido_dev_toggle_always_uv(), fido_dev_force_pin_change(), fido_dev_set_pin_minlen(), and fido_dev_set_pin_minlen_rpid() are defined in <fido/err.h>. On success, FIDO_OK is returned.

fido_cbor_info_maxrpid_minpinlen(3), fido_cred_pin_minlen(3), fido_dev_get_cbor_info(3), fido_dev_reset(3)
March 30, 2022 Linux 5.17.4-200.fc35.x86_64