Function nginx::RSA_meth_set_sign

pub unsafe extern "C" fn RSA_meth_set_sign(
    rsa: *mut RSA_METHOD, 
    sign: Option<unsafe extern "C" fn(type_: c_int, m: *const c_uchar, m_length: c_uint, sigret: *mut c_uchar, siglen: *mut c_uint, rsa: *const RSA) -> c_int>
) -> c_int