I am trying to set cipher list as like below :

std::string ciphers = "AES256-GCM-SHA384:AES256-SHA256:AES256-SHA:AES128-GCM-SHA256:AES128-SHA256:AES128-SHA"

returnCode = ldap_set_option(NULL, LDAP_OPT_X_TLS_CIPHER_SUITE, ciphers.c_str());

But, it returns an error : "TLS could not set cipher list ....."

Can anyone suggest what is the right way of doing this?