gnutls\_x509\_crt\_check\_issuer(3) gnutls gnutls\_x509\_crt\_check\_issuer(3)

# [NAME](#NAME)

gnutls\_x509\_crt\_check\_issuer - API function

# [SYNOPSIS](#SYNOPSIS)

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

**unsigned gnutls\_x509\_crt\_check\_issuer(gnutls\_x509\_crt\_t cert, gnutls\_x509\_crt\_t issuer);**

# [ARGUMENTS](#ARGUMENTS)

[gnutls\_x509\_crt\_t cert](#gnutls_x509_crt_t)

is the certificate to be checked

[gnutls\_x509\_crt\_t issuer](#gnutls_x509_crt_t~2)

is the certificate of a possible issuer

# [DESCRIPTION](#DESCRIPTION)

This function will check if the given certificate was issued by the given issuer. It checks the DN fields and the authority key identifier and subject key identifier fields match.

If the same certificate is provided at the *cert* and *issuer* fields, it will check whether the certificate is self-signed.

# [RETURNS](#RETURNS)

It will return [true (1)](/man/os/gnutls/true.1) if the given certificate is issued by the given issuer, and false (0) if not.

# [REPORTING BUGS](#REPORTING_BUGS)

Report bugs to <bugs@gnutls.org>.  
Home page: https://www.gnutls.org

# [COPYRIGHT](#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](#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/](https://www.gnutls.org/manual/)

3.8.13 gnutls

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Document: gnutls_x509_crt_check_issuer(3) from gnutls 3.8.13-r3 (Chainguard OS)
Source: https://gitlab.com/gnutls/gnutls