www.westphal-electronic.com

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Hints concerning use of API (Application Program Interface)
for the ZRANDOM generators

General

• The API is realized by a Windows DLL.
• The DLL contains a function that starts the ZRANDOM generator.
• The DLL function can be called by several programming languages (e.g. Delphi, C++, Visual Basic).
• A function call provides 20000 true random bits.

Advantages

• Generation of true random bits "on demand".
• A simple function call starts the ZRANDOM generator.
• Generation control (e.g. physical mode or XOR mode) by function parameters.
• No necessity to use the ZRANDOM graphic control panels.
• Random bit transfer is feasible by a binary file or by use of an array variable.
• Storing random bits on hard disk can be deactivated (=> random bit transfer only via RAM).
• When required a protocol file with the FIPS401-1 test results can be created.

Demo source code for a DLL function call in Delphi

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unit Unit1_CallZran;  // Windows API (Application Program Interface)
// This file calls the function StartZrandom in Zran.dll
// in order to generate 20000 true random bits on demand.
// This file is a DELPHI Unit used by the DELPHI Project CallZran.dpr
// Zran.dll can also be used by C++ or Visual Basic!

interface

uses
Windows, Messages, SysUtils, Classes, Graphics, Controls, Forms, Dialogs,
StdCtrls, ExtCtrls, ComCtrls;

implementation

var
returnvalue,i : longint;
randombits : array[0..19999] of longint;
s,allbits : string;

function StartZrandom(baseaddress,mode:longint; filename_bin,filename_log:PChar;
writefiles:longint; var randombits : array of longint) : longint;
stdcall; external 'Zran.dll';

begin

{
The function parameters have following meanings:
1. Base address of the ISA-Slot-Card (default: $210).
   The "$" sign indicates that 210 is a hex number.
   (Not necessary for USB version.)
2. Generation mode (0: physical, 1: XOR)
3. Binary file name
4. Protocol file name
5. Write files (0: No, 1: Yes)
6. Array [0..19999] of generated True Random Bits (longint)
Possible function results:
return value = 0 -> No Error
return value > 0 -> Error described in the protocol file
}

// ---------------- Start ZRANDOM generator ----------------------------------------------
returnvalue:=StartZrandom($210,0,'ZBITS.BIN','ZBITS.LOG',1,randombits);
// -------------------------------------------------------------------------------------------------------

s:=Format('%d',[returnvalue]);
ShowMessage('Return value = '+s);

// Show first 1000 True Random Bits:
allbits:='';
for i:=0 to 999 do
begin
 s:=Format('%d',[randombits[i]]);
 allbits:=allbits+s;
 if ((i+1) mod 80)=0 then allbits:=allbits+#13
end;
ShowMessage(allbits);

end.

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The function call is marked red.
The result of this demo program is a window containing the first 1000 (of 20000 generated) true random bits.

Here you will find a text file with the demo program.

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Links concerning use of DLL functions in Delphi, C++, Visial Basic

About Delphi Programming
http://delphi.about.com/

Dynamic Link Libraries and Delphi
http://delphi.about.com/library/weekly/aa041100a.htm

Visual Basic source code of DLL use
http://delphi.about.com/gi/dynamic/offsite.htm?site=http://www.avdf.com/aug95/samp1%5Fdll3.html

About C/C++
http://cplus.about.com/

About Visual Basic
http://visualbasic.about.com/

Programmers Heaven
http://www.programmersheaven.com/

EXE vs. DLL - Which one?
http://www.visualcadd.org/articles/api/api2.html#vcsetup