CURLOPT_TLS13_CIPHERS(3) Library Functions Manual CURLOPT_TLS13_CIPHERS(3)
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 Li-
breSSL >= 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), CUR-
LOPT_PROXY_TLS13_CIPHERS(3), CURLOPT_SSLVERSION(3), CURLOPT_SSL_CI-
PHER_LIST(3), CURLOPT_USE_SSL(3)
libcurl 2026-07-12 CURLOPT_TLS13_CIPHERS(3)
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