CURLOPT_SSL_EC_CURVES(3)   Library Functions Manual   CURLOPT_SSL_EC_CURVES(3)

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)

libcurl                          April 26 2024        CURLOPT_SSL_EC_CURVES(3)