fido_bio_info_type(3)

fido_bio_info_type3

Fido2 biometric sensor information api

Part of fido_bio_info_new(3).

Usage

#include <fido.h>

#include <fido/bio.h>

fido_bio_info_t *

fido_bio_info_new(void);

void

fido_bio_info_free(fido_bio_info_t **info_p);

uint8_t

fido_bio_info_type(const fido_bio_info_t *info);

uint8_t

fido_bio_info_max_samples(const fido_bio_info_t *info);

Overview

Biometric sensor metadata is abstracted in libfido2 by the fido_bio_info_t type.

The functions described in this page allow a fido_bio_info_t type to be allocated, deallocated, and inspected. For device operations on fido_bio_info_t, please refer to fido_bio_dev_get_info(3).

The fido_bio_info_new() function returns a pointer to a newly allocated, empty fido_bio_info_t type. If memory cannot be allocated, NULL is returned.

The fido_bio_info_free() function releases the memory backing *info_p, where *info_p must have been previously allocated by fido_bio_info_new(). On return, *info_p is set to NULL. Either info_p or *info_p may be NULL, in which case fido_bio_info_free() is a NOP.

The fido_bio_info_type() function returns the fingerprint sensor type, which is 1 for touch sensors, and 2 for swipe sensors.

The fido_bio_info_max_samples() function returns the maximum number of successful samples required for enrollment.

Releases

4 releases since Debian 11 (Bullseye); the text changed 1 time.

  1. 11
  2. 12–Arch

From libfido2 1.17.0-1 in Arch Linux 2026-11-01. Parsed by carta from the page's mdoc source.