---
name: "gnutls_x509_crt_set_subject_alt_name"
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_subject_alt_name"
---

# gnutls\_x509\_crt\_set\_subject\_alt\_name(3)

API function

## NAME

gnutls\_x509\_crt\_set\_subject\_alt\_name - API function

## SYNOPSIS

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

**int gnutls\_x509\_crt\_set\_subject\_alt\_name(gnutls\_x509\_crt\_t** *crt***, gnutls\_x509\_subject\_alt\_name\_t** *type***, const void \*** *data***, unsigned int** *data\_size***, unsigned int** *flags***);**

## ARGUMENTS

- gnutls\_x509\_crt\_t crt

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

- gnutls\_x509\_subject\_alt\_name\_t type

  is one of the gnutls\_x509\_subject\_alt\_name\_t enumerations

- const void \* data

  The data to be set

- unsigned int data\_size

  The size of data to be set

- unsigned int flags

  GNUTLS\_FSAN\_SET to clear previous data or GNUTLS\_FSAN\_APPEND to append.

## DESCRIPTION

This function will set the subject alternative name certificate extension. It can set the following types: **GNUTLS\_SAN\_DNSNAME** as a text string, **GNUTLS\_SAN\_RFC822NAME** as a text string, **GNUTLS\_SAN\_URI** as a text string, **GNUTLS\_SAN\_IPADDRESS** as a binary IP address (4 or 16 bytes), **GNUTLS\_SAN\_OTHERNAME\_XMPP** as a UTF8 string (since 3.5.0).

Since version 3.5.7 the **GNUTLS\_SAN\_RFC822NAME**, **GNUTLS\_SAN\_DNSNAME**, and **GNUTLS\_SAN\_OTHERNAME\_XMPP** are converted to ACE format when necessary.

## RETURNS

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

## SINCE

2\.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/