--- c: Copyright (C) Daniel Stenberg, , et al. SPDX-License-Identifier: curl Title: CURLOPT_TLS13_CIPHERS Section: 3 Source: libcurl 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) Protocol: - TLS TLS-backend: - OpenSSL - wolfSSL - mbedTLS - rustls Added-in: 7.61.0 --- # NAME CURLOPT_TLS13_CIPHERS - ciphers suites to use for TLS 1.3 # SYNOPSIS ~~~c #include 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: ~~~c "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% # EXAMPLE ~~~c 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% # RETURN VALUE Returns CURLE_OK if supported, CURLE_NOT_BUILT_IN otherwise.