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

# [NAME](#NAME)

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

# [SYNOPSIS](#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](#ARGUMENTS)

[gnutls\_x509\_crt\_t cert](#gnutls_x509_crt_t)

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

[gnutls\_digest\_algorithm\_t algo](#gnutls_digest_algorithm_t)

is a digest algorithm

[void * buf](#void)

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

[size\_t * buf\_size](#size_t)

initially holds the size of *buf*

# [DESCRIPTION](#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](#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](#REPORTING_BUGS)

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

# [COPYRIGHT](#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](#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/](https://www.gnutls.org/manual/)

3.8.13 gnutls

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Document: gnutls_x509_crt_get_fingerprint(3) from gnutls 3.8.13-r3 (Chainguard OS)
Source: https://gitlab.com/gnutls/gnutls