CURLOPT_TLS13_CIPHERS

Section: curl_easy_setopt options (3)
Updated: November 04, 2020
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NAME

CURLOPT_TLS13_CIPHERS - specify ciphers suites to use for TLS 1.3

SYNOPSIS

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

DESCRIPTION

Pass a char *, 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.

You'll 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. If you are using a different SSL backend you can try setting TLS 1.3 cipher suites by using the CURLOPT_SSL_CIPHER_LIST option.

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

DEFAULT

NULL, use internal default

PROTOCOLS

All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

EXAMPLE

CURL *curl = curl_easy_init();
if(curl) {
  curl_easy_setopt(curl, CURLOPT_URL, "https://example.com/");
  curl_easy_setopt(curl, CURLOPT_TLS13_CIPHERS,
                   "TLS13-CHACHA20-POLY1305-SHA256");
  ret = curl_easy_perform(curl);
  curl_easy_cleanup(curl);
}

AVAILABILITY

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

RETURN VALUE

Returns CURLE_OK if supported, CURLE_NOT_BUILT_IN otherwise.