NAME

       CURLOPT_PROXY_CRLFILE - HTTPS proxy Certificate Revocation List file

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_CRLFILE, char *file);

DESCRIPTION

       This option is for connecting to an HTTPS proxy, not an HTTPS server.

       Pass  a  char  pointer to a null-terminated string naming a file with the concatenation of
       CRL (in PEM format) to use in the  certificate  validation  that  occurs  during  the  SSL
       exchange.

       When  curl  is  built to use GnuTLS, there is no way to influence the use of CRL passed to
       help  in  the  verification  process.  When  libcurl  is  built  with   OpenSSL   support,
       X509_V_FLAG_CRL_CHECK  and  X509_V_FLAG_CRL_CHECK_ALL  are  both  set, requiring CRL check
       against all the elements of the certificate chain if a CRL file is passed.

       This   option   makes    sense    only    when    used    in    combination    with    the
       CURLOPT_PROXY_SSL_VERIFYPEER(3) option.

       A  specific  error code (CURLE_SSL_CRL_BADFILE) is defined with the option. It is returned
       when the SSL exchange fails  because  the  CRL  file  cannot  be  loaded.   A  failure  in
       certificate verification due to a revocation information found in the CRL does not trigger
       this specific error.

       The application does not have to keep the string around after setting this option.

DEFAULT

       NULL

PROTOCOLS

       This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

       This option works only with the following TLS backends: GnuTLS, OpenSSL and mbedTLS

EXAMPLE

       int main(void)
       {
         CURL *curl = curl_easy_init();
         if(curl) {
           CURLcode res;
           curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
           curl_easy_setopt(curl, CURLOPT_PROXY, "https://localhost:80");
           curl_easy_setopt(curl, CURLOPT_PROXY_CRLFILE, "/etc/certs/crl.pem");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in curl 7.52.0

RETURN VALUE

       Returns  CURLE_OK  if  the  option  is  supported,   CURLE_UNKNOWN_OPTION   if   not,   or
       CURLE_OUT_OF_MEMORY if there was insufficient heap space.

SEE ALSO

       CURLOPT_PROXY_SSL_VERIFYHOST(3),                          CURLOPT_PROXY_SSL_VERIFYPEER(3),
       CURLOPT_SSL_VERIFYHOST(3), CURLOPT_SSL_VERIFYPEER(3)