I am trying to disable Server's Certificate Issue Date Validation in libcurl. For that, I have registered a own_verify_callback function by calling SSL_CTX_set_verify in sslContextVerify callback (set via curl_easy_setopt(curl, CURLOPT_SSL_CTX_FUNCTION, sslContextVerify)).
The "own_verify_callback" gets called (I have print in this function and they are printed on console) and it returns 1 but still curl connection fails (i.e., curl_easy_perform returns with an error) with error "SSL certificate verify result: certificate is not yet valid (9)". However, it should allow the connection. I have set the system's date and time to 1990 and I was testing the Issue Date Validation. Looks like there is a bug in libcurl or I am missing something important?. Is there something I am doing wrong or is it a well-known bug? My code is below: https://stackoverflow.com/questions/59662414/disabling-ssl-issue-date-validation-in-libcurl