---
name: "gnutls_certificate_set_x509_key_mem"
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_mem"
---

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

API function

## NAME

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

## SYNOPSIS

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

**int gnutls\_certificate\_set\_x509\_key\_mem(gnutls\_certificate\_credentials\_t** *res***, const gnutls\_datum\_t \*** *cert***, const gnutls\_datum\_t \*** *key***, gnutls\_x509\_crt\_fmt\_t** *type***);**

## ARGUMENTS

- gnutls\_certificate\_credentials\_t res

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

- const gnutls\_datum\_t \* cert

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

- const gnutls\_datum\_t \* key

  is the private key, or **NULL**

- gnutls\_x509\_crt\_fmt\_t type

  is PEM or DER

## 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.

Note that the keyUsage (2.5.29.15) PKIX extension in X.509 certificates is supported. This means that certificates intended for signing cannot be used for ciphersuites that require encryption.

If the certificate and the private key are given in PEM encoding then the strings that hold their values must be null terminated.

The  *key* may be **NULL** if you are using a sign callback, see **gnutls\_sign\_callback\_set()**.

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).

## 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/