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23 .TH CURLOPT_SSLVERSION 3 "January 10, 2018" "libcurl 7.59.0" "curl_easy_setopt options"
26 CURLOPT_SSLVERSION \- set preferred TLS/SSL version
28 #include <curl/curl.h>
30 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSLVERSION, long version);
32 Pass a long as parameter to control which version of SSL/TLS to attempt to
35 Use one of the available defines for this purpose. The available options are:
37 .IP CURL_SSLVERSION_DEFAULT
38 The default action. This will attempt to figure out the remote SSL protocol
40 .IP CURL_SSLVERSION_TLSv1
42 .IP CURL_SSLVERSION_SSLv2
44 .IP CURL_SSLVERSION_SSLv3
46 .IP CURL_SSLVERSION_TLSv1_0
47 TLSv1.0 (Added in 7.34.0)
48 .IP CURL_SSLVERSION_TLSv1_1
49 TLSv1.1 (Added in 7.34.0)
50 .IP CURL_SSLVERSION_TLSv1_2
51 TLSv1.2 (Added in 7.34.0)
52 .IP CURL_SSLVERSION_TLSv1_3
53 TLSv1.3 (Added in 7.52.0)
55 The maximum TLS version can be set by using \fIone\fP of the
56 CURL_SSLVERSION_MAX_ macros below. It is also possible to OR \fIone\fP of the
57 CURL_SSLVERSION_ macros with \fIone\fP of the CURL_SSLVERSION_MAX_ macros.
58 The MAX macros are not supported for SSL backends axTLS or wolfSSL.
60 .IP CURL_SSLVERSION_MAX_DEFAULT
61 The flag defines the maximum supported TLS version as TLSv1.2, or the default
62 value from the SSL library.
64 .IP CURL_SSLVERSION_MAX_TLSv1_0
65 The flag defines maximum supported TLS version as TLSv1.0.
67 .IP CURL_SSLVERSION_MAX_TLSv1_1
68 The flag defines maximum supported TLS version as TLSv1.1.
70 .IP CURL_SSLVERSION_MAX_TLSv1_2
71 The flag defines maximum supported TLS version as TLSv1.2.
73 .IP CURL_SSLVERSION_MAX_TLSv1_3
74 The flag defines maximum supported TLS version as TLSv1.3.
78 CURL_SSLVERSION_DEFAULT
80 All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
83 CURL *curl = curl_easy_init();
85 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
87 /* ask libcurl to use TLS version 1.0 or later */
88 curl_easy_setopt(curl, CURLOPT_SSLVERSION, CURL_SSLVERSION_TLSv1);
90 /* Perform the request */
91 curl_easy_perform(curl);
95 SSLv2 is disabled by default since 7.18.1. Other SSL versions availability may
96 vary depending on which backend libcurl has been built to use.
98 SSLv3 is disabled by default since 7.39.0.
100 Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.
102 .BR CURLOPT_USE_SSL "(3), " CURLOPT_HTTP_VERSION "(3), "
103 .BR CURLOPT_IPRESOLVE "(3) "