NAME

       CURLOPT_PROXY_SSLVERSION - set preferred proxy TLS/SSL version

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLVERSION, long version);

DESCRIPTION

       Pass  a  long  as  parameter  to  control  which version of SSL/TLS to attempt to use when
       connecting to an HTTPS proxy.

       Use one of the available defines for this purpose. The available options are:

              CURL_SSLVERSION_DEFAULT
                     The default action. This will attempt to figure out the remote SSL  protocol
                     version.

              CURL_SSLVERSION_TLSv1
                     TLSv1.x

              CURL_SSLVERSION_TLSv1_0
                     TLSv1.0

              CURL_SSLVERSION_TLSv1_1
                     TLSv1.1

              CURL_SSLVERSION_TLSv1_2
                     TLSv1.2

              CURL_SSLVERSION_TLSv1_3
                     TLSv1.3
       The  maximum TLS version can be set by using one of the CURL_SSLVERSION_MAX_ macros below.
       It  is  also  possible  to  OR  one  of  the  CURL_SSLVERSION_  macros  with  one  of  the
       CURL_SSLVERSION_MAX_  macros.   The MAX macros are not supported for SSL backends axTLS or
       wolfSSL.

              CURL_SSLVERSION_MAX_DEFAULT
                     The flag defines the maximum  supported  TLS  version  as  TLSv1.2,  or  the
                     default value from the SSL library.  (Added in 7.54.0)

              CURL_SSLVERSION_MAX_TLSv1_0
                     The  flag  defines  maximum  supported  TLS  version  as TLSv1.0.  (Added in
                     7.54.0)

              CURL_SSLVERSION_MAX_TLSv1_1
                     The flag defines maximum  supported  TLS  version  as  TLSv1.1.   (Added  in
                     7.54.0)

              CURL_SSLVERSION_MAX_TLSv1_2
                     The  flag  defines  maximum  supported  TLS  version  as TLSv1.2.  (Added in
                     7.54.0)

              CURL_SSLVERSION_MAX_TLSv1_3
                     The flag defines maximum  supported  TLS  version  as  TLSv1.3.   (Added  in
                     7.54.0)

DEFAULT

       CURL_SSLVERSION_DEFAULT

PROTOCOLS

       All

EXAMPLE

       CURL *curl = curl_easy_init();
       if(curl) {
         curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");

         /* ask libcurl to use TLS version 1.0 or later */
         curl_easy_setopt(curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1);

         /* Perform the request */
         curl_easy_perform(curl);
       }

AVAILABILITY

       Added in 7.52.0

RETURN VALUE

       Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO

       CURLOPT_USE_SSL(3), CURLOPT_HTTP_VERSION(3), CURLOPT_IPRESOLVE(3) CURLOPT_SSLVERSION(3),