gnutls_certificate_expiration_time_peers - Linux

Overview

gnutls_certificate_expiration_time_peers retrieves the expiration time of the certificate chain for the server on the established connection. It is a TLS library function that verifies the server certificate and checks if it has expired or not.

Syntax

gnutls_certificate_expiration_time_peers(gnutls_session_t session) -> time_t

Options/Flags

None.

Examples

To check the expiration time of the server certificate, use the following code:

#include <gnutls/gnutls.h>

time_t expiration_time;

gnutls_session_t session;
gnutls_init(&session, GNUTLS_CLIENT);

if (gnutls_certificate_expiration_time_peers(session, &expiration_time) == 0) {
  printf("Server certificate expires at: %s", ctime(&expiration_time));
} else {
  printf("Error retrieving certificate expiration time.");
}

gnutls_deinit(session);

Common Issues

• If the server certificate is invalid or has expired, the function will return a negative value.
• If the server does not provide a certificate, the function will return GNUTLS_E_NO_CERTIFICATE.

Integration

This function can be used in conjunction with other GnuTLS functions to verify the server certificate and check its validity.

Related Commands

• gnutls_certificate_verify_peers2: Verifies the server certificate and checks its validity.
• gnutls_session_init: Initializes a TLS session.