---
name: "gnutls_certificate_set_x509_key"
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_certificate_set_x509_key"
---

# gnutls\_certificate\_set\_x509\_key(3)

API function

## NAME

gnutls\_certificate\_set\_x509\_key - API function

## SYNOPSIS

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

**int gnutls\_certificate\_set\_x509\_key(gnutls\_certificate\_credentials\_t** *res***, gnutls\_x509\_crt\_t \*** *cert\_list***, int** *cert\_list\_size***, gnutls\_x509\_privkey\_t** *key***);**

## ARGUMENTS

- gnutls\_certificate\_credentials\_t res

  is a **gnutls\_certificate\_credentials\_t** type.

- gnutls\_x509\_crt\_t \* cert\_list

  contains a certificate list (path) for the specified private key

- int cert\_list\_size

  holds the size of the certificate list

- gnutls\_x509\_privkey\_t key

  is a **gnutls\_x509\_privkey\_t** key

## DESCRIPTION

This function sets a certificate/private key pair in the gnutls\_certificate\_credentials\_t type.  This function may be called more than once, in case multiple keys/certificates exist for the server.  For clients that wants to send more than their own end entity certificate (e.g., also an intermediate CA cert) then put the certificate chain in  *cert\_list* .

Note that the certificates and keys provided, can be safely deinitialized after this function is called.

If that function fails to load the  *res* type is at an undefined state, it must not be reused to load other keys or certificates.

Note that, this function by default returns zero on success and a negative value on error. Since 3.5.6, when the flag **GNUTLS\_CERTIFICATE\_API\_V2** is set using **gnutls\_certificate\_set\_flags()** it returns an index (greater or equal to zero). That index can be used to other functions to refer to the added key-pair.

## RETURNS

On success this functions returns zero, and otherwise a negative value on error (see above for modifying that behavior).

## SINCE

2\.4.0

## 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/