Tribblix: manual page: CURLOPT_SSL

CURLOPT_SSL_FALSESTART(3) Introduction to Library Functions

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

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

curl_easy_setopt(3) returns a CURLcode indicating success or error.

CURLE_OK (0) means everything was OK, non-zero means an error
occurred, see libcurl-errors(3).