Function PEM_write_PKCS8PrivateKey 

pub unsafe extern "C" fn PEM_write_PKCS8PrivateKey(
    fp: *mut FILE,
    in_: *const EVP_PKEY,
    enc: *const EVP_CIPHER,
    pass: *const c_char,
    pass_len: c_int,
    cb: pem_password_cb,
    userdata: *mut c_void,
) -> c_int