NAME

       CURLOPT_TLS13_CIPHERS - ciphers suites to use for TLS 1.3

SYNOPSIS

       #include <curl/curl.h>

       CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLS13_CIPHERS, char *list);

DESCRIPTION

       Pass  a  char  pointer,  pointing  to  a null-terminated string holding the list of cipher
       suites to use for the TLS 1.3 connection. The  list  must  be  syntactically  correct,  it
       consists of one or more cipher suite strings separated by colons.

       Find more details about cipher lists on this URL:

        https://curl.se/docs/ssl-ciphers.html

       This  option  is  currently used only when curl is built to use OpenSSL 1.1.1 or later, or
       Schannel. If you are using a different SSL backend you can  try  setting  TLS  1.3  cipher
       suites by using the CURLOPT_SSL_CIPHER_LIST(3) option.

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

DEFAULT

       NULL, use internal built-in

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 Schannel

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_TLS13_CIPHERS,
                            "TLS_CHACHA20_POLY1305_SHA256");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

HISTORY

       Added in 7.61.0 for OpenSSL. Available when built with OpenSSL >= 1.1.1.

       Added in 7.85.0 for Schannel.

AVAILABILITY

       Added in curl 7.61.0

RETURN VALUE

       Returns CURLE_OK if supported, CURLE_NOT_BUILT_IN otherwise.

SEE ALSO

       CURLOPT_PROXY_SSLVERSION(3),                             CURLOPT_PROXY_SSL_CIPHER_LIST(3),
       CURLOPT_PROXY_TLS13_CIPHERS(3),     CURLOPT_SSLVERSION(3),     CURLOPT_SSL_CIPHER_LIST(3),
       CURLOPT_USE_SSL(3)