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.

       For setting TLS 1.2 (1.1, 1.0) ciphers see CURLOPT_SSL_CIPHER_LIST(3).

       A valid example of a cipher list is:
       "TLS_AES_128_GCM_SHA256:TLS_CHACHA20_POLY1305_SHA256"

       Find more details about cipher lists on this URL:

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

       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 to internal default.

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

HISTORY

       OpenSSL support added in 7.61.0, available when built with OpenSSL >= 1.1.1.  LibreSSL support  added  in
       8.3.0,  available  when  built with LibreSSL >= 3.4.1.  wolfSSL support added in 8.10.0.  mbedTLS support
       added in 8.10.0, available when built with mbedTLS >= 3.6.0.  Rustls support added in 8.10.0.

       Before  curl  8.10.0  with  mbedTLS  or  wolfSSL,  TLS  1.3  cipher  suites  were  set   by   using   the
       CURLOPT_SSL_CIPHER_LIST(3) option.

AVAILABILITY

       Added in curl 7.61.0

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).

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)

libcurl                                            2025-03-05                           CURLOPT_TLS13_CIPHERS(3)