我正在编写一项服务，该服务应该从移动设备接收采用Base64编码的DER格式PKCS#10证书请求，然后返回从CA获得的证书。我正在尝试使用“https://CA-server/certsrv/mscep/mscep.dll?operation=PKIOperation&Message=urlencoded请求”$ca_link_device="https://..../certsrv/mscep/mscep.dll";$URL=$ca_link_device."?operation=PKIOperation&Message=".urlencode($BinarySecurityTok