[DllImport("Crypt32.dll", SetLastError = true)]
public static extern bool CryptSignAndEncryptMessage(
ref CRYPT_SIGN_MESSAGE_PARA pSignPara,
ref CRYPT_ENCRYPT_MESSAGE_PARA pEncryptPara,
uint cRecipientCert,
IntPtr[] rgpRecipientCert,
byte[] pbToBeSignedAndEncrypted,
uint cbToBeSignedAndEncrypted,
byte[] pbSignedAndEncryptedBlob,
ref uint pcbSignedAndEncryptedBlob
);