---
name: "gnutls_x509_crt_set_spki"
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_set_spki"
---

# gnutls\_x509\_crt\_set\_spki(3)

API function

## NAME

gnutls\_x509\_crt\_set\_spki - API function

## SYNOPSIS

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

**int gnutls\_x509\_crt\_set\_spki(gnutls\_x509\_crt\_t** *crt***, const gnutls\_x509\_spki\_t** *spki***, unsigned int** *flags***);**

## ARGUMENTS

- gnutls\_x509\_crt\_t crt

  a certificate of type **gnutls\_x509\_crt\_t**

- const gnutls\_x509\_spki\_t spki

  a SubjectPublicKeyInfo structure of type **gnutls\_x509\_spki\_t**

- unsigned int flags

  must be zero

## DESCRIPTION

This function will set the certificate's subject public key information explicitly. This is intended to be used in the cases where a single public key (e.g., RSA) can be used for multiple signature algorithms (RSA PKCS1-1.5, and RSA-PSS).

To export the public key (i.e., the SubjectPublicKeyInfo part), check **gnutls\_pubkey\_import\_x509()**.

## RETURNS

On success, **GNUTLS\_E\_SUCCESS** (0) is returned, otherwise a negative error value.

## SINCE

3\.6.0

## 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/