---
name: "gnutls_x509_crt_sign2"
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_sign2"
---

# gnutls\_x509\_crt\_sign2(3)

API function

## NAME

gnutls\_x509\_crt\_sign2 - API function

## SYNOPSIS

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

**int gnutls\_x509\_crt\_sign2(gnutls\_x509\_crt\_t** *crt***, gnutls\_x509\_crt\_t** *issuer***, gnutls\_x509\_privkey\_t** *issuer\_key***, gnutls\_digest\_algorithm\_t** *dig***, unsigned int** *flags***);**

## ARGUMENTS

- gnutls\_x509\_crt\_t crt

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

- gnutls\_x509\_crt\_t issuer

  is the certificate of the certificate issuer

- gnutls\_x509\_privkey\_t issuer\_key

  holds the issuer's private key

- gnutls\_digest\_algorithm\_t dig

  The message digest to use, **GNUTLS\_DIG\_SHA256** is a safe choice

- unsigned int flags

  must be 0

## DESCRIPTION

This function will sign the certificate with the issuer's private key, and will copy the issuer's information into the certificate.

This must be the last step in a certificate generation since all the previously set parameters are now signed.

A known limitation of this function is, that a newly-signed certificate will not be fully functional (e.g., for signature verification), until it is exported an re-imported.

After GnuTLS 3.6.1 the value of  *dig* may be **GNUTLS\_DIG\_UNKNOWN**, and in that case, a suitable but reasonable for the key algorithm will be selected.

## RETURNS

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

## 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/