.\" generated by cd2nroff 0.1 from CURLOPT_TLS13_CIPHERS.md
.TH CURLOPT_TLS13_CIPHERS 3 "2024-04-19" libcurl
.SH NAME
CURLOPT_TLS13_CIPHERS \- ciphers suites to use for TLS 1.3
.SH SYNOPSIS
.nf
#include <curl/curl.h>

CURLcode curl_easy_setopt(CURL *handle, CURLOPT_TLS13_CIPHERS, char *list);
.fi
.SH 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 \fICURLOPT_SSL_CIPHER_LIST(3)\fP
option.

The application does not have to keep the string around after setting this
option.
.SH DEFAULT
NULL, use internal default
.SH PROTOCOLS
All TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

This option works only with the following TLS backends:
OpenSSL, Schannel and rustls
.SH EXAMPLE
.nf
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);
  }
}
.fi
.SH AVAILABILITY
Added in 7.61.0 for OpenSSL. Available when built with OpenSSL >= 1.1.1.

Added in 7.85.0 for Schannel.
.SH RETURN VALUE
Returns CURLE_OK if supported, CURLE_NOT_BUILT_IN otherwise.
.SH SEE ALSO
.BR CURLOPT_PROXY_SSLVERSION (3),
.BR CURLOPT_PROXY_SSL_CIPHER_LIST (3),
.BR CURLOPT_PROXY_TLS13_CIPHERS (3),
.BR CURLOPT_SSLVERSION (3),
.BR CURLOPT_SSL_CIPHER_LIST (3),
.BR CURLOPT_USE_SSL (3)