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23 .TH CURLOPT_SSL_FALSESTART 3 "May 15, 2017" "libcurl 7.59.0" "curl_easy_setopt options"
26 CURLOPT_SSL_FALSESTART \- enable TLS false start
28 #include <curl/curl.h>
30 CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_FALSESTART, long enable);
32 Pass a long as parameter set to 1L to enable or 0 to disable.
34 This option determines whether libcurl should use false start during the TLS
35 handshake. False start is a mode where a TLS client will start sending
36 application data before verifying the server's Finished message, thus saving a
37 round trip when performing a full handshake.
41 All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
44 CURL *curl = curl_easy_init();
46 curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
47 curl_easy_setopt(curl, CURLOPT_SSL_FALSESTART, 1L);
48 curl_easy_perform(curl);
52 Added in 7.42.0. This option is currently only supported by the NSS and
53 Secure Transport (on iOS 7.0 or later, or OS X 10.9 or later) TLS backends.
55 Returns CURLE_OK if false start is supported by the SSL backend, otherwise
56 returns CURLE_NOT_BUILT_IN.