Tribblix: manual page: CURLOPT_TLS13

CURLOPT_TLS13_CIPHERS(3) Introduction to Library Functions

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).