NAME¶

CURLOPT_SSL_EC_CURVES - key exchange curves

SYNOPSIS¶

#include <curl/curl.h>
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_SSL_EC_CURVES, char *alg_list);

DESCRIPTION¶

Pass a string as parameter with a colon delimited list of (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).

DEFAULT¶

"", embedded in SSL backend

PROTOCOLS¶

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 7.73.0. Supported by the OpenSSL backend.

RETURN VALUE¶

Returns CURLE_OK if the option is supported, and CURLE_UNKNOWN_OPTION if not.

SEE ALSO¶

CURLOPT_SSL_CIPHER_LIST(3), CURLOPT_SSL_OPTIONS(3), CURLOPT_TLS13_CIPHERS(3)