gnutls_certificate_set_params_function - Linux


gnutls_certificate_set_params_function is used to set the callback function for certificate parameters. It is typically used by applications to provide custom logic for modifying or validating certificate parameters.


gnutls_certificate_set_params_function(cert, params_function)


  • cert: A gnutls_certificate_t object representing the certificate to set the parameters function for.
  • params_function: A callback function that takes a gnutls_certificate_params_t object as an argument. This function should modify the parameters as needed.


The following example shows how to use gnutls_certificate_set_params_function to modify the key usage parameters of a certificate:

#include <gnutls/gnutls.h>

void modify_key_usage(gnutls_certificate_params_t params) {
  /* Modify the key usage parameters as needed. */
  gnutls_certificate_params_set_key_usage(params, GNUTLS_KEY_USAGE_DIGITAL_SIGNATURE);

int main() {
  gnutls_certificate_t cert;

  gnutls_certificate_set_params_function(cert, modify_key_usage);

  /* Use the certificate as needed. */


  return 0;

Common Issues

One common issue when using gnutls_certificate_set_params_function is that the callback function may not be called consistently across different platforms. To avoid this, it is recommended to set the parameters directly using gnutls_certificate_params_set_* functions instead of relying on the callback.


gnutls_certificate_set_params_function can be combined with other GnuTLS functions to create powerful applications. For example, it can be used to create custom certificate validators that enforce specific security requirements.

Related Commands

  • gnutls_certificate_init: Initializes a certificate object.
  • gnutls_certificate_deinit: Deinitializes a certificate object.
  • gnutls_certificate_params_set_*: Functions to set specific certificate parameters.