Tribblix: manual page: CURLOPT_SSL_EC

CURLOPT_SSL_EC_CURVES(3) Introduction to Library Functions

NAME

CURLOPT_SSL_EC_CURVES - key exchange curves

SYNOPSIS

#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_EC_CURVES, char *list);

DESCRIPTION

Pass a string as parameter with a colon delimited list of Elliptic
curve (EC) algorithms. This option defines the client's key exchange
algorithms in the SSL handshake (if the SSL backend libcurl is built
to use supports it).

The application does not have to keep the string around after setting
this option.

Using this option multiple times makes the last set string override
the previous ones. Set it to NULL to restore back to internal
default.

DEFAULT

"", embedded in SSL backend

PROTOCOLS

This functionality affects all TLS based protocols: HTTPS, FTPS,
IMAPS, POP3S, SMTPS etc.

This option works only with the following TLS backends: OpenSSL and
wolfSSL

EXAMPLE

int main(void)
{
CURL *curl = curl_easy_init();
if(curl) {
CURLcode res;
curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
curl_easy_setopt(curl, CURLOPT_SSL_EC_CURVES, "X25519:P-521");
res = curl_easy_perform(curl);
curl_easy_cleanup(curl);
}
}

AVAILABILITY

Added in curl 7.73.0

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).