/**********************************************************/
  pStreamIn := TMemoryStream.Create;
  pStreamIn.LoadFromFile( 'c:\temp\test.txt' );

  pStreamOut := TMemoryStream.Create;

  FillChar(SigParams, SizeOf( CRYPT_SIGN_MESSAGE_PARA ), #0);

  MessageArray[1] := pStreamIn.Memory;
  MessageSize[1] := pStreamIn.Size;
  MessageCert[1] := aCert;

  SigParams.cbSize := SizeOF( CRYPT_SIGN_MESSAGE_PARA );
  SigParams.dwMsgEncodingType := X509_ASN_ENCODING or PKCS_7_ASN_ENCODING;
  SigParams.pSigningCert := aCert;
  SigParams.HashAlgorithm.pszObjId := szOID_CP_GOST_R3411;
  SigParams.cMsgCert := 1;
  SigParams.rgpMsgCert := @MessageCert;

  aSize := 0;
  if not (CryptSignMessage(@SigParams, false, 1, @MessageArray, @MessageSize, nil, aSize)) then
    mText.Lines.Add('CryptSignMessage OK. Размер буфера: ' + IntToStr(GetLastError) )
  else
    mText.Lines.Add(Err('Ошибка CryptSignMessage. Size: ' + IntToStr(aSize)));

 pStreamOut.Size := aSize;

  if not (CryptSignMessage( @SigParams, false, 1, @MessageArray, @MessageSize, pStreamOut.Memory, aSize )) then
    mText.Lines.Add(Err('Файл не подписан'));

  pStreamOut.SaveToFile('c:\temp\test.txt.sig');
    mText.Lines.Add('Файл успешно подписан');
/**********************************************************/