Provided by: libcurl4-doc_8.9.1-2ubuntu2.1_all
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 starts sending application data before verifying the server's Finished message, thus saving a round trip when performing a full handshake.
DEFAULT
0
PROTOCOLS
This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc. This option works only with the following TLS backends: Secure Transport
EXAMPLE
int main(void) { 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 curl 7.42.0
RETURN VALUE
Returns CURLE_OK if false start is supported by the SSL backend, otherwise returns CURLE_NOT_BUILT_IN.
SEE ALSO
CURLOPT_TCP_FASTOPEN(3)