plucky (3) CURLOPT_CRLFILE.3.gz

NAME

       CURLOPT_CRLFILE - Certificate Revocation List file

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

       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.  Also
       note  that  CURLOPT_CRLFILE(3) implies CURLSSLOPT_NO_PARTIALCHAIN (see CURLOPT_SSL_OPTIONS(3)) since curl
       7.71.0 due to an OpenSSL bug.

       This option makes sense only when used in combination with the CURLOPT_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.

       Using this option multiple times makes the last set string override the previous ones. Set it to NULL  to
       disable its use again.

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, mbedTLS and rustls

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_CRLFILE, "/etc/certs/crl.pem");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

AVAILABILITY

       Added in curl 7.19.0

RETURN VALUE

       curl_easy_setopt(3) returns a CURLcode indicating success or error.

       CURLE_OK (0) means everything was OK, non-zero means an error occurred, see libcurl-errors(3).

SEE ALSO

       CURLOPT_PROXY_CRLFILE(3), CURLOPT_SSL_VERIFYHOST(3), CURLOPT_SSL_VERIFYPEER(3)