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.