Constant openssl_sys::SSL_EXT_TLS1_3_SERVER_HELLO
pub const SSL_EXT_TLS1_3_SERVER_HELLO: c_uint = 0x0200;
The portability is definied by:
#[cfg(ossl111)]
pub const SSL_EXT_TLS1_3_SERVER_HELLO: c_uint = 0x0200;
#[cfg(ossl111)]