FIDO_BIO_INFO_NEW(3) | Library Functions Manual | FIDO_BIO_INFO_NEW(3)

# NAME

`fido_bio_info_new`, `fido_bio_info_free`, `fido_bio_info_type`, `fido_bio_info_max_samples` — FIDO2 biometric sensor information API

# SYNOPSIS

library “libfido2” libcbor libcrypto libz
`#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);

# DESCRIPTION

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.

# SEE ALSO

fido_bio_dev_get_info(3), fido_bio_enroll_new(3), fido_bio_template(3)

July 9, 2025 | Debian