CryptMsgEncodeAndSignCTL

[DllImport("Crypt32.dll", SetLastError = true)]
public static extern bool CryptMsgEncodeAndSignCTL(
   uint dwMsgEncodingType,
   IntPtr pCtlInfo,
   IntPtr rgSigners,
   IntPtr rgUnauthAttrs,
   IntPtr pbEncoded,
   ref uint pcbEncoded
);

Microsoft documentation: Link