--- c: Copyright (C) Daniel Stenberg, , et al. SPDX-License-Identifier: curl Title: CURLOPT_PROXY_SSLVERSION Section: 3 Source: libcurl See-also: - CURLOPT_HTTP_VERSION (3) - CURLOPT_IPRESOLVE (3) - CURLOPT_SSLVERSION (3) - CURLOPT_USE_SSL (3) Protocol: - TLS TLS-backend: - All --- # NAME CURLOPT_PROXY_SSLVERSION - preferred HTTPS proxy TLS version # SYNOPSIS ~~~c #include 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 attempts 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 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) ## In versions of curl prior to 7.54 the CURL_SSLVERSION_TLS options were documented to allow *only* the specified TLS version, but behavior was inconsistent depending on the TLS library. # DEFAULT CURL_SSLVERSION_DEFAULT # EXAMPLE ~~~c 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); } } ~~~ # AVAILABILITY Added in 7.52.0 # RETURN VALUE Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.