CURLOPT_SSL_FALSESTART(3) curl_easy_setopt options CURLOPT_SSL_FALSESTART(3)
NAME
CURLOPT_SSL_FALSESTART - TLS false start
SYNOPSIS
#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_FALSESTART, long enable);
DESCRIPTION
Pass a long as parameter set to 1L to enable or 0 to disable.
This option determines whether libcurl should use false start during
the TLS handshake. False start is a mode where a TLS client will start
sending application data before verifying the server's Finished mes-
sage, thus saving a round trip when performing a full handshake.
DEFAULT
0
PROTOCOLS
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.
EXAMPLE
CURL *curl = curl_easy_init();
if(curl) {
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com");
curl_easy_setopt(curl, CURLOPT_SSL_FALSESTART, 1L);
curl_easy_perform(curl);
}
AVAILABILITY
Added in 7.42.0. This option is currently only supported by the NSS and
Secure Transport (on iOS 7.0 or later, or OS X 10.9 or later) TLS back-
ends.
RETURN VALUE
Returns CURLE_OK if false start is supported by the SSL backend, other-
wise returns CURLE_NOT_BUILT_IN.
SEE ALSO
CURLOPT_TCP_FASTOPEN(3),
libcurl 7.81.0 November 26, 2021 CURLOPT_SSL_FALSESTART(3)
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