.\" generated by cd2nroff 0.1 from CURLOPT_PROXY_SSLVERSION.md
.TH CURLOPT_PROXY_SSLVERSION 3 "2024-11-07" libcurl
.SH NAME
CURLOPT_PROXY_SSLVERSION \- preferred HTTPS proxy TLS version
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXY_SSLVERSION,
                          long version);
.fi
.SH 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:
.IP CURL_SSLVERSION_DEFAULT
The default action. This attempts to figure out the remote SSL protocol
version.
.IP CURL_SSLVERSION_TLSv1
TLSv1.x
.IP CURL_SSLVERSION_TLSv1_0
TLSv1.0
.IP CURL_SSLVERSION_TLSv1_1
TLSv1.1
.IP CURL_SSLVERSION_TLSv1_2
TLSv1.2
.IP CURL_SSLVERSION_TLSv1_3
TLSv1.3
.PP
The maximum TLS version can be set by using \fIone\fP of the CURL_SSLVERSION_MAX_
macros below. It is also possible to OR \fIone\fP of the CURL_SSLVERSION_ macros
with \fIone\fP of the CURL_SSLVERSION_MAX_ macros. The MAX macros are not
supported for wolfSSL.
.IP 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)
.IP CURL_SSLVERSION_MAX_TLSv1_0
The flag defines maximum supported TLS version as TLSv1.0.
(Added in 7.54.0)
.IP CURL_SSLVERSION_MAX_TLSv1_1
The flag defines maximum supported TLS version as TLSv1.1.
(Added in 7.54.0)
.IP CURL_SSLVERSION_MAX_TLSv1_2
The flag defines maximum supported TLS version as TLSv1.2.
(Added in 7.54.0)
.IP CURL_SSLVERSION_MAX_TLSv1_3
The flag defines maximum supported TLS version as TLSv1.3.
(Added in 7.54.0)
.PP
In versions of curl prior to 7.54 the CURL_SSLVERSION_TLS options were
documented to allow \fIonly\fP the specified TLS version, but behavior was
inconsistent depending on the TLS library.
.SH DEFAULT
CURL_SSLVERSION_DEFAULT
.SH PROTOCOLS
This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

All TLS backends support this option.
.SH EXAMPLE
.nf
int main(void)
{
  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);
  }
}
.fi
.SH AVAILABILITY
Added in curl 7.52.0
.SH RETURN VALUE
Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
.SH SEE ALSO
.BR CURLOPT_HTTP_VERSION (3),
.BR CURLOPT_IPRESOLVE (3),
.BR CURLOPT_SSLVERSION (3),
.BR CURLOPT_USE_SSL (3)