Constant openssl_sys::EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY
pub const EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY: c_int = 1;
The portability is definied by:
#[cfg(ossl111)]
pub const EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY: c_int = 1;
#[cfg(ossl111)]