---
name: "fido_bio_info_max_samples"
section: "3"
platform: "linux"
package: "libfido2"
version: "1.17.0-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/fido_bio_info_new"
---

# fido\_bio\_info\_max\_samples(3)

FIDO2 biometric sensor information API

Part of [fido\_bio\_info\_new(3)](/fido_bio_info_new/3.md).

## NAME

**fido\_bio\_info\_new**, **fido\_bio\_info\_free**, **fido\_bio\_info\_type**, **fido\_bio\_info\_max\_samples** – FIDO2 biometric sensor information API

## SYNOPSIS

**#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)](/fido_bio_dev_get_info/3.md).

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_dev_get_info/3.md), [fido\_bio\_enroll\_new(3)](/fido_bio_enroll_new/3.md), [fido\_bio\_template(3)](/fido_bio_template/3.md)