Function botan_sys::botan_x509_cert_get_issuer_dn

pub unsafe extern "C" fn botan_x509_cert_get_issuer_dn(
    cert: botan_x509_cert_t, 
    key: *const c_char, 
    index: usize, 
    out: *mut u8, 
    out_len: *mut usize
) -> c_int