NAME

       CURLOPT_SSL_CIPHER_LIST - ciphers to use for TLS

SYNOPSIS

       #include <curl/curl.h>

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

DESCRIPTION

       Pass  a  char pointer, pointing to a null-terminated string holding the list of ciphers to
       use for the SSL connection. The list must be syntactically correct, it consists of one  or
       more  cipher  strings separated by colons. Commas or spaces are also acceptable separators
       but colons are normally used, !, - and + can be used as operators.

       For OpenSSL and GnuTLS valid examples of cipher lists include RC4-SHA, SHA1+DES, TLSv1 and
       DEFAULT. The default list is normally set when you compile OpenSSL.

       For    wolfSSL,    valid    examples    of   cipher   lists   include   ECDHE-RSA-RC4-SHA,
       AES256-SHA:AES256-SHA256, etc.

       For    mbedTLS    and    BearSSL,    valid    examples    of    cipher    lists    include
       ECDHE-RSA-CHACHA20-POLY1305:ECDHE-RSA-AES128-GCM-SHA256,   or   when   using   IANA  names
       TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256:TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,    etc.
       With  mbedTLS  and BearSSL you do not add/remove ciphers. If one uses this option then all
       known ciphers are disabled and only those passed in are enabled.

       For Schannel, you can use this option to set algorithms but not  specific  cipher  suites.
       Refer to the ciphers lists document for algorithms.

       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.

DEFAULT

       NULL, use built-in list

PROTOCOLS

       This functionality affects all TLS based protocols: HTTPS, FTPS, IMAPS, POP3S, SMTPS etc.

       This  option  works  only  with  the  following  TLS  backends:  BearSSL, GnuTLS, OpenSSL,
       Schannel, Secure Transport, mbedTLS 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_SSL_CIPHER_LIST, "TLSv1");
           res = curl_easy_perform(curl);
           curl_easy_cleanup(curl);
         }
       }

HISTORY

       Added in 7.9, in 7.83.0 for BearSSL, in 8.8.0 for mbedTLS

AVAILABILITY

       Added in curl 7.9

RETURN VALUE

       Returns CURLE_OK if TLS is supported, CURLE_UNKNOWN_OPTION if not, or  CURLE_OUT_OF_MEMORY
       if there was insufficient heap space.

SEE ALSO

       CURLOPT_PROXY_SSL_CIPHER_LIST(3),  CURLOPT_PROXY_TLS13_CIPHERS(3),  CURLOPT_SSLVERSION(3),
       CURLOPT_TLS13_CIPHERS(3), CURLOPT_USE_SSL(3)