---
name: "gnutls_x509_cidr_to_rfc5280"
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_cidr_to_rfc5280"
---

# gnutls\_x509\_cidr\_to\_rfc5280(3)

API function

## NAME

gnutls\_x509\_cidr\_to\_rfc5280 - API function

## SYNOPSIS

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

**int gnutls\_x509\_cidr\_to\_rfc5280(const char \*** *cidr***, gnutls\_datum\_t \*** *cidr\_rfc5280***);**

## ARGUMENTS

- const char \* cidr

  CIDR in RFC4632 format (IP/prefix), null-terminated

- gnutls\_datum\_t \* cidr\_rfc5280

  CIDR range converted to RFC5280 format

## DESCRIPTION

This function will convert text CIDR range with prefix (such as '10.0.0.0/8') to RFC5280 (IP address in network byte order followed by its network mask). Works for both IPv4 and IPv6.

The resulting object is directly usable for IP name constraints usage, for example in functions **gnutls\_x509\_name\_constraints\_add\_permitted** or **gnutls\_x509\_name\_constraints\_add\_excluded**.

The data in datum needs to be deallocated using **gnutls\_free()**.

## RETURNS

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

## SINCE

3\.5.4

## 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/