---
name: "gnutls_x509_crt_get_fingerprint"
section: "3"
platform: "linux"
package: "gnutls"
version: "3.8.13-3"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/gnutls_x509_crt_get_fingerprint"
---

# gnutls\_x509\_crt\_get\_fingerprint(3)

API function

## NAME

gnutls\_x509\_crt\_get\_fingerprint - API function

## SYNOPSIS

**#include \<gnutls/x509.h\>**

**int gnutls\_x509\_crt\_get\_fingerprint(gnutls\_x509\_crt\_t** *cert***, gnutls\_digest\_algorithm\_t** *algo***, void \*** *buf***, size\_t \*** *buf\_size***);**

## ARGUMENTS

- gnutls\_x509\_crt\_t cert

  should contain a **gnutls\_x509\_crt\_t** type

- gnutls\_digest\_algorithm\_t algo

  is a digest algorithm

- void \* buf

  a pointer to a structure to hold the fingerprint (may be null)

- size\_t \* buf\_size

  initially holds the size of  *buf*

## DESCRIPTION

This function will calculate and copy the certificate's fingerprint in the provided buffer. The fingerprint is a hash of the DER-encoded data of the certificate.

If the buffer is null then only the size will be filled.

## RETURNS

**GNUTLS\_E\_SHORT\_MEMORY\_BUFFER** if the provided buffer is not long enough, and in that case the \*buf\_size will be updated with the required size.  On success 0 is returned.

## REPORTING BUGS

Report bugs to \<bugs@gnutls.org\>.\
 Home page: https://www.gnutls.org

## COPYRIGHT

Copyright © 2001-2023 Free Software Foundation, Inc., and others.\
 Copying and distribution of this file, with or without modification, are permitted in any medium without royalty provided the copyright notice and this notice are preserved.

## SEE ALSO

The full documentation for **gnutls** is maintained as a Texinfo manual. If the /usr/share/doc/gnutls/ directory does not contain the HTML form visit

- https://www.gnutls.org/manual/