今天又改了CRACKME

作者：mobiledu2502897737 | 来源：互联网 | 2022-12-20 14:16

前几天写了个CRACKME，把它贴到看雪论坛，十分钟后就有人破解出来了。好郁闷。第二天改了下再放上去，两个小时后，注册机都有人写出来了。以前没写过软件注册程序，也不知道别人怎么写的，更没看过

前几天写了个CRACKME，把它贴到看雪论坛，十分钟后就有人破解出来了。好郁闷。第二天改了下再放上去，两个小时后，注册机都有人写出来了。以前没写过软件注册程序，也不知道别人怎么写的，更没看过别人写的例子。所以写的时候搞得程序里到处都是“奥尔良”(用来填充用户名字符数量的)..今天又改了下，用MD5算法加密的。验证注册码时也用MD5加密后再验证..不知道还能否有人写出注册机。

unit Utmain;

interface

///////////////////////////////////////by lanyus greathjw@163.com///////////////////////////////////////////////

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

type
TForm1 = class(TForm)
    Label2: TLabel;
    Ed1: TEdit;
    Button1: TButton;
    Button2: TButton;
    Label3: TLabel;
    EdUser: TEdit;
    StatusBar1: TStatusBar;
    Ed2: TEdit;
    Ed4: TEdit;
    Ed3: TEdit;
    Label1: TLabel;
    Label4: TLabel;
    Label5: TLabel;
    Ed5: TEdit;
    Ed6: TEdit;
    Ed8: TEdit;
    Ed7: TEdit;
    Label6: TLabel;
    Label7: TLabel;
    Label8: TLabel;
    Label9: TLabel;
    procedure Button2Click(Sender: TObject);
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure FormShow(Sender: TObject);
    procedure regsuc(reg:bool);
    procedure FormClose(Sender: TObject; var Action: TCloseAction);
    procedure Ed3KeyPress(Sender: TObject; var Key: Char);
    procedure Ed1KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed2KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed3KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed5KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed6KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed7KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
    procedure Ed4KeyUp(Sender: TObject; var Key: Word; Shift: TShiftState);
private
    { Private declarations }
public
    { Public declarations }
end;

var
Form1: TForm1;
reg,regl:boolean; //注册标志
regStr:string;
user,sn:string;
validdate:string; //有效期

implementation

uses MD5;

{$R *.dfm}

function strToHEX(str:string):string;
var
i,p:integer;
begin
for i:=1 to Length(str) do
begin
    p:=ord(str[i]);
    result:=result+Inttohex(p,2);
end;
end;

function HexToStr(str:string):string;

var
i,p,re1:integer;
begin
if Length(str)<>16 then
begin
    result:='0';
    exit;
end;
p:=1;
for i:=1 to 8 do
begin
    re1:=Strtoint('$'+copy(str,p,2));
    result:=result+chr(re1);
    p:=p+2;
end;
end;

function ReverseStr(str:string):string;
var
res:string;
i:integer;
begin
if str='' then
result:=''
else
begin
   res:=StringOfChar('1',Length(str));
   for i:=1 to Length(str) do
   begin
    res[i]:=str[Length(str)+1-i];
   end;
   result:=res;
end;
end;

function CheckSn2(username,usersn:string;var usersn_date:string):bool;
var
m,sn_md5:MD5Digest;
re:string;
i:integer;
s21,s22:string[32];
usersn_sn,usersn_sn_md5:string;
realsn:string;
begin
result:=false;
usersn_date:='';
m:=MD5String(username);
re:=MD5Print(m);
for i:=0 to 10 do
begin
    m:= MD5String(re);
    re:=MD5Print(m);
end;
s21:=re;
s22:=reversestr(s21);

for i:=0 to 10 do

begin
    m:= MD5String(s22);
    s22:=MD5Print(m);
end;
s22:=UPpercase(s22);

s22:=copy(s22,3,16);
realsn:=s22;
for i:=1 to 32 do
begin
    if i in [1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31] then
      usersn_sn:=usersn_sn+usersn[i];
    if i in [2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32] then
      usersn_date:=usersn_date+usersn[i];
end;
usersn_date:=HexToStr(ReverseStr(usersn_date));

try
    StrToInt(usersn_date)
except
    usersn_date:='00000000';
    result:=False;
    exit;
end;
if (strtoint(usersn_date)<20050101) or (strtoint(usersn_date)>22000101) then
begin
    usersn_date:='00000000';
    result:=False;
    exit;
end;
usersn_sn_md5:=usersn_sn;
for i:=0 to 10 do
begin
    sn_md5:=MD5String(usersn_sn_md5);
    usersn_sn_md5:=MD5Print(sn_md5);
end;
for i:=0 to 10 do
begin
    sn_md5:=MD5String(realsn);
    realsn:=MD5Print(sn_md5);
end;
if usersn_sn_md5=realsn then
begin
    result:=true;
    exit;
end;

end;

function CheckSn(username,usersn:string;var usersn_date:string):bool;
var
m,sn_md5:MD5Digest;
re:string;
i:integer;
s21,s22:string[32];
usersn_sn,usersn_sn_md5:string;
realsn:string;
begin
result:=false;
usersn_date:='';
m:=MD5String(username);
re:=MD5Print(m);

for i:=0 to 10 do
begin
    m:= MD5String(re);
    re:=MD5Print(m);
end;
s21:=re;

s22:=reversestr(s21);

for i:=0 to 10 do

begin
    m:= MD5String(s22);
    s22:=MD5Print(m);
end;
s22:=UPpercase(s22);

s22:=copy(s22,3,16);
realsn:=s22;
for i:=1 to 32 do

begin
    if i in [1,3,5,7,9,11,13,15,17,19,21,23,25,27,29,31] then
      usersn_sn:=usersn_sn+usersn[i];
    if i in [2,4,6,8,10,12,14,16,18,20,22,24,26,28,30,32] then
      usersn_date:=usersn_date+usersn[i];
end;
usersn_date:=HexToStr(ReverseStr(usersn_date));
try
    StrToInt(usersn_date)
except
    usersn_date:='00000000';
    result:=False;
    exit;
end;
if (strtoint(usersn_date)<20050101) or (strtoint(usersn_date)>22000101) then
begin
    usersn_date:='00000000';
    result:=False;
    exit;
end;
usersn_sn_md5:=usersn_sn;
for i:=0 to 10 do
begin
    sn_md5:=MD5String(usersn_sn_md5);
    usersn_sn_md5:=MD5Print(sn_md5);
end;
for i:=0 to 10 do

begin
    sn_md5:=MD5String(realsn);
    realsn:=MD5Print(sn_md5);
end;
if usersn_sn_md5=realsn then

begin
result:=true;
exit;
end;

end;

procedure TForm1.regsuc(reg:bool);
begin
if reg then StatusBar1.panels[0].text:=regStr;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
close;
end;

procedure TForm1.Button1Click(Sender: TObject);
var
RF:TStringList;
filepath,username,sn:string;
begin
if (EdUser.Text='') or (length(EdUser.Text)>24) then
begin
    showmessage('用户名长度出错');
    exit;
end;
if (length(trim(Ed1.Text))<>4) or (length(trim(Ed2.Text))<>4) or
    (length(trim(Ed3.Text))<>4) or (length(trim(Ed4.Text))<>4) then
begin
    showmessage('注册码要32位');
    exit;
end;
filepath:=ExtractFilePath(Application.ExeName)+'reg.dll';
rf:=TStringList.Create;
rf.LoadFromFile(filepath);
username:=trim(EdUser.Text);
sn:=Ed1.Text+Ed2.Text+Ed3.Text+Ed4.Text+Ed5.Text+Ed6.Text+Ed7.Text+Ed8.Text;
RF.Values['username']:=username;
RF.Values['sn']:=sn;
RF.Values['reg']:='0';
RF.SaveToFile(filepath);
RF.Free;
showmessage('请重启软件以验证注册码');
close;
end;

procedure TForm1.FormCreate(Sender: TObject);
var
f:TextFile;
R:string;
RF:TStringList;
creg:string;
begin
reg:=false;

regl:=false;
r:=extractfilepath(Application.ExeName)+'reg.dll';
if not FileExists(r) then
begin
    AssignFile(F,r);
    rewrite(f);
    writeln(f,'username=username');
    writeln(f,'SN=12345678901234567890123456789012');
    writeln(f,'reg=0');

    closeFile(f);
    exit;
end
else
begin
    RF:=TStringList.Create;
    RF.LoadFromFile(r);
    user:=trim(RF.Values['username']);
    sn:=trim(RF.Values['sn']);
    creg:=trim(RF.Values['reg']);
    RF.Free;
end;
if (user='') or (length(sn)<>32) then exit;
if (length(creg)<>1) or (creg='2') then
begin
   RF:=TStringList.Create;
   RF.Values['username']:='username';
   RF.Values['sn']:='12345678901234567890123456789012';
   rf.Values['reg']:='2';
   rf.SaveToFile(r);
   StatusBar1.Panels[0].Text:='未注册，请勿尝试破解软件';
   RF.Free;
   exit;
end;
setlength(validdate,8);
if checksn(user,sn,validdate) then
begin
    if StrToInt(validdate)    reg:=true;
    regStr:='已注册为 '+user+' 有效期至'+copy(validdate,1,4)+'年'+
            copy(validdate,5,2)+'月'+copy(validdate,7,2)+'日';
end;
end;

procedure TForm1.FormShow(Sender: TObject);
begin
if reg then regl:=true;
if regl then regsuc(true);

end;

//关闭时再次全新验证注册码
procedure TForm1.FormClose(Sender: TObject; var Action: TCloseAction);
var
f:TextFile;
R:string;
RF:TStringList;
creg:string;
validdate2:string;
begin
if not regl then exit;

r:=extractfilepath(Application.ExeName)+'reg.dll';
if not FileExists(r) then
begin
    AssignFile(F,r);
    rewrite(f);
    writeln(f,'username=username');
    writeln(f,'SN=123456789012345678901234');
    writeln(f,'reg=0');
    closeFile(f);
    exit;
end
else
begin
    RF:=TStringList.Create;
    RF.LoadFromFile(r);
    creg:=trim(RF.Values['reg']);
    user:=trim(RF.Values['username']);
    sn:=trim(RF.Values['sn']);
    RF.Free;
end;

if checksn2(user,sn,validdate2) then
begin
    if strtoint(validdate2)>strtoint(formatdatetime('yyyymmdd',now())) then
      exit
    else
    begin
      RF:=TStringList.Create;
      RF.LoadFromFile(r);
      RF.Values['reg']:='2';
      RF.Values['username']:='username';
      RF.Values['sn']:='1234567890123456789012';
      rf.SaveToFile(r);
      RF.Free;
    end;
end
else
begin
    RF:=TStringList.Create;
    RF.LoadFromFile(r);
    RF.Values['reg']:='2';
    RF.Values['username']:='username';
    RF.Values['sn']:='1234567890123456789012';
    rf.SaveToFile(r);
    RF.Free;
end;
end;

procedure TForm1.Ed3KeyPress(Sender: TObject; var Key: Char);
begin
if Key in ['G'..'Z','a'..'z'] then key:=#0;
end;

procedure TForm1.Ed1KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed1.Text)=4 then Ed2.SetFocus;
end;

procedure TForm1.Ed2KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed2.Text)=4 then Ed3.SetFocus;
end;

procedure TForm1.Ed3KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed3.Text)=4 then Ed4.SetFocus;
end;

procedure TForm1.Ed5KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed5.Text)=4 then Ed6.SetFocus;
end;

procedure TForm1.Ed6KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed6.Text)=4 then Ed7.SetFocus;
end;

procedure TForm1.Ed7KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed7.Text)=4 then Ed8.SetFocus;
end;

procedure TForm1.Ed4KeyUp(Sender: TObject; var Key: Word;
Shift: TShiftState);
begin
if Length(Ed4.Text)=4 then Ed5.SetFocus;
end;

end.

////////////////////////////////////////////////////////////////////////////////////////MD5.PAS/此单元从网上下载////////////////////////////////////////////////////

// tabs = 2
// -----------------------------------------------------------------------------------------------
//
//                                 MD5 Message-Digest for Delphi 4
//
//                                 Delphi 4 Unit implementing the
//                      RSA Data Security, Inc. MD5 Message-Digest Algorithm
//
//                          Implementation of Ronald L. Rivest's RFC 1321
//
//                      Copyright ?1997-1999 Medienagentur Fichtner & Meyer
//                                  Written by Matthias Fichtner
//
// -----------------------------------------------------------------------------------------------
//               See RFC 1321 for RSA Data Security's copyright and license notice!
// -----------------------------------------------------------------------------------------------
//
//     14-Jun-97 mf Implemented MD5 according to RFC 1321                           RFC 1321
//     16-Jun-97 mf Initial release of the compiled unit (no source code)           RFC 1321
//     28-Feb-99 mf Added MD5Match function for comparing two digests               RFC 1321
//     13-Sep-99 mf Reworked the entire unit                                        RFC 1321
//     17-Sep-99 mf Reworked the "Test Driver" project                              RFC 1321
//     19-Sep-99 mf Release of sources for MD5 unit and "Test Driver" project       RFC 1321
//
// -----------------------------------------------------------------------------------------------
//                   The latest release of md5.pas will always be available from
//                  the distribution site at: http://www.fichtner.net/delphi/md5/
// -----------------------------------------------------------------------------------------------
//                       Please send questions, bug reports and suggestions
//                      regarding this code to: mfichtner@fichtner-meyer.com
// -----------------------------------------------------------------------------------------------
//                        This code is provided "as is" without express or
//                     implied warranty of any kind. Use it at your own risk.
// -----------------------------------------------------------------------------------------------

unit md5;

// -----------------------------------------------------------------------------------------------
INTERFACE
// -----------------------------------------------------------------------------------------------

uses
Windows;

type
MD5Count = array[0..1] of DWORD;
MD5State = array[0..3] of DWORD;
MD5Block = array[0..15] of DWORD;
MD5CBits = array[0..7] of byte;
MD5Digest = array[0..15] of byte;
MD5Buffer = array[0..63] of byte;
MD5COntext= record
  State: MD5State;
  Count: MD5Count;
  Buffer: MD5Buffer;
end;

procedure MD5Init(var Context: MD5Context);
procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest);

function MD5String(M: string): MD5Digest;
function MD5File(N: string): MD5Digest;
function MD5Print(D: MD5Digest): string;

function MD5Match(D1, D2: MD5Digest): boolean;

// -----------------------------------------------------------------------------------------------
IMPLEMENTATION
// -----------------------------------------------------------------------------------------------

var
PADDING: MD5Buffer = (
  $80, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00,
  $00, $00, $00, $00, $00, $00, $00, $00
);

function F(x, y, z: DWORD): DWORD;
begin
Result := (x and y) or ((not x) and z);
end;

function G(x, y, z: DWORD): DWORD;
begin
Result := (x and z) or (y and (not z));
end;

function H(x, y, z: DWORD): DWORD;
begin
Result := x xor y xor z;
end;

function I(x, y, z: DWORD): DWORD;
begin
Result := y xor (x or (not z));
end;

procedure rot(var x: DWORD; n: BYTE);
begin
x := (x shl n) or (x shr (32 - n));
end;

procedure FF(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, F(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end;

procedure GG(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, G(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end;

procedure HH(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, H(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end;

procedure II(var a: DWORD; b, c, d, x: DWORD; s: BYTE; ac: DWORD);
begin
inc(a, I(b, c, d) + x + ac);
rot(a, s);
inc(a, b);
end;

// -----------------------------------------------------------------------------------------------

// Encode Count bytes at Source into (Count / 4) DWORDs at Target
procedure Encode(Source, Target: pointer; Count: longword);
var
S: PByte;
T: PDWORD;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count div 4 do begin
  T^ := S^;
  inc(S);
  T^ := T^ or (S^ shl 8);
  inc(S);
  T^ := T^ or (S^ shl 16);
  inc(S);
  T^ := T^ or (S^ shl 24);
  inc(S);
  inc(T);
end;
end;

// Decode Count DWORDs at Source into (Count * 4) Bytes at Target
procedure Decode(Source, Target: pointer; Count: longword);
var
S: PDWORD;
T: PByte;
I: longword;
begin
S := Source;
T := Target;
for I := 1 to Count do begin
  T^ := S^ and $ff;
  inc(T);
  T^ := (S^ shr 8) and $ff;
  inc(T);
  T^ := (S^ shr 16) and $ff;
  inc(T);
  T^ := (S^ shr 24) and $ff;
  inc(T);
  inc(S);
end;
end;

// Transform State according to first 64 bytes at Buffer
procedure Transform(Buffer: pointer; var State: MD5State);
var
a, b, c, d: DWORD;
Block: MD5Block;
begin
Encode(Buffer, @Block, 64);
a := State[0];
b := State[1];
c := State[2];
d := State[3];
FF (a, b, c, d, Block[ 0], 7, $d76aa478);
FF (d, a, b, c, Block[ 1], 12, $e8c7b756);
FF (c, d, a, b, Block[ 2], 17, $242070db);
FF (b, c, d, a, Block[ 3], 22, $c1bdceee);
FF (a, b, c, d, Block[ 4], 7, $f57c0faf);
FF (d, a, b, c, Block[ 5], 12, $4787c62a);
FF (c, d, a, b, Block[ 6], 17, $a8304613);
FF (b, c, d, a, Block[ 7], 22, $fd469501);
FF (a, b, c, d, Block[ 8], 7, $698098d8);
FF (d, a, b, c, Block[ 9], 12, $8b44f7af);
FF (c, d, a, b, Block[10], 17, $ffff5bb1);
FF (b, c, d, a, Block[11], 22, $895cd7be);
FF (a, b, c, d, Block[12], 7, $6b901122);
FF (d, a, b, c, Block[13], 12, $fd987193);
FF (c, d, a, b, Block[14], 17, $a679438e);
FF (b, c, d, a, Block[15], 22, $49b40821);
GG (a, b, c, d, Block[ 1], 5, $f61e2562);
GG (d, a, b, c, Block[ 6], 9, $c040b340);
GG (c, d, a, b, Block[11], 14, $265e5a51);
GG (b, c, d, a, Block[ 0], 20, $e9b6c7aa);
GG (a, b, c, d, Block[ 5], 5, $d62f105d);
GG (d, a, b, c, Block[10], 9, $2441453);
GG (c, d, a, b, Block[15], 14, $d8a1e681);
GG (b, c, d, a, Block[ 4], 20, $e7d3fbc8);
GG (a, b, c, d, Block[ 9], 5, $21e1cde6);
GG (d, a, b, c, Block[14], 9, $c33707d6);
GG (c, d, a, b, Block[ 3], 14, $f4d50d87);
GG (b, c, d, a, Block[ 8], 20, $455a14ed);
GG (a, b, c, d, Block[13], 5, $a9e3e905);
GG (d, a, b, c, Block[ 2], 9, $fcefa3f8);
GG (c, d, a, b, Block[ 7], 14, $676f02d9);
GG (b, c, d, a, Block[12], 20, $8d2a4c8a);
HH (a, b, c, d, Block[ 5], 4, $fffa3942);
HH (d, a, b, c, Block[ 8], 11, $8771f681);
HH (c, d, a, b, Block[11], 16, $6d9d6122);
HH (b, c, d, a, Block[14], 23, $fde5380c);
HH (a, b, c, d, Block[ 1], 4, $a4beea44);
HH (d, a, b, c, Block[ 4], 11, $4bdecfa9);
HH (c, d, a, b, Block[ 7], 16, $f6bb4b60);
HH (b, c, d, a, Block[10], 23, $bebfbc70);
HH (a, b, c, d, Block[13], 4, $289b7ec6);
HH (d, a, b, c, Block[ 0], 11, $eaa127fa);
HH (c, d, a, b, Block[ 3], 16, $d4ef3085);
HH (b, c, d, a, Block[ 6], 23, $4881d05);
HH (a, b, c, d, Block[ 9], 4, $d9d4d039);
HH (d, a, b, c, Block[12], 11, $e6db99e5);
HH (c, d, a, b, Block[15], 16, $1fa27cf8);
HH (b, c, d, a, Block[ 2], 23, $c4ac5665);
II (a, b, c, d, Block[ 0], 6, $f4292244);
II (d, a, b, c, Block[ 7], 10, $432aff97);
II (c, d, a, b, Block[14], 15, $ab9423a7);
II (b, c, d, a, Block[ 5], 21, $fc93a039);
II (a, b, c, d, Block[12], 6, $655b59c3);
II (d, a, b, c, Block[ 3], 10, $8f0ccc92);
II (c, d, a, b, Block[10], 15, $ffeff47d);
II (b, c, d, a, Block[ 1], 21, $85845dd1);
II (a, b, c, d, Block[ 8], 6, $6fa87e4f);
II (d, a, b, c, Block[15], 10, $fe2ce6e0);
II (c, d, a, b, Block[ 6], 15, $a3014314);
II (b, c, d, a, Block[13], 21, $4e0811a1);
II (a, b, c, d, Block[ 4], 6, $f7537e82);
II (d, a, b, c, Block[11], 10, $bd3af235);
II (c, d, a, b, Block[ 2], 15, $2ad7d2bb);
II (b, c, d, a, Block[ 9], 21, $eb86d391);
inc(State[0], a);
inc(State[1], b);
inc(State[2], c);
inc(State[3], d);
end;

// -----------------------------------------------------------------------------------------------

// Initialize given Context
procedure MD5Init(var Context: MD5Context);
begin
with Context do begin
  State[0] := $67452301;
  State[1] := $efcdab89;
  State[2] := $98badcfe;
  State[3] := $10325476;
  Count[0] := 0;
  Count[1] := 0;
  ZeroMemory(@Buffer, SizeOf(MD5Buffer));
end;
end;

// Update given Context to include Length bytes of Input
procedure MD5Update(var Context: MD5Context; Input: pChar; Length: longword);
var
Index: longword;
PartLen: longword;
I: longword;
begin
with Context do begin
  Index := (Count[0] shr 3) and $3f;
  inc(Count[0], Length shl 3);
  if Count[0] <(Length shl 3) then inc(Count[1]);
  inc(Count[1], Length shr 29);
end;
PartLen := 64 - Index;
if Length >= PartLen then begin
  CopyMemory(@Context.Buffer[Index], Input, PartLen);
  Transform(@Context.Buffer, Context.State);
  I := PartLen;
  while I + 63    Transform(@Input[I], Context.State);
   inc(I, 64);
  end;
  Index := 0;
end else I := 0;
CopyMemory(@Context.Buffer[Index], @Input[I], Length - I);
end;

// Finalize given Context, create Digest and zeroize Context
procedure MD5Final(var Context: MD5Context; var Digest: MD5Digest);
var
Bits: MD5CBits;
Index: longword;
PadLen: longword;
begin
Decode(@Context.Count, @Bits, 2);
Index := (Context.Count[0] shr 3) and $3f;
if Index <56 then PadLen := 56 - Index else PadLen := 120 - Index;
MD5Update(Context, @PADDING, PadLen);
MD5Update(Context, @Bits, 8);
Decode(@Context.State, @Digest, 4);
ZeroMemory(@Context, SizeOf(MD5Context));
end;

// -----------------------------------------------------------------------------------------------

// Create digest of given Message
function MD5String(M: string): MD5Digest;
var
Context: MD5Context;
begin
MD5Init(Context);
MD5Update(Context, pChar(M), length(M));
MD5Final(Context, Result);
end;

// Create digest of file with given Name
function MD5File(N: string): MD5Digest;
var
FileHandle: THandle;
MapHandle: THandle;
ViewPointer: pointer;
Context: MD5Context;
begin
MD5Init(Context);
FileHandle := CreateFile(pChar(N), GENERIC_READ, FILE_SHARE_READ or FILE_SHARE_WRITE,
  nil, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL or FILE_FLAG_SEQUENTIAL_SCAN, 0);
if FileHandle <> INVALID_HANDLE_VALUE then try
  MapHandle := CreateFileMapping(FileHandle, nil, PAGE_READONLY, 0, 0, nil);
  if MapHandle <> 0 then try
   ViewPointer := MapViewOfFile(MapHandle, FILE_MAP_READ, 0, 0, 0);
   if ViewPointer <> nil then try
    MD5Update(Context, ViewPointer, GetFileSize(FileHandle, nil));
   finally
    UnmapViewOfFile(ViewPointer);
   end;
  finally
   CloseHandle(MapHandle);
  end;
finally
  CloseHandle(FileHandle);
end;
MD5Final(Context, Result);
end;

// Create hex representation of given Digest
function MD5Print(D: MD5Digest): string;
var
I: byte;
const
Digits: array[0..15] of char =
('0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f');
begin
Result := '';
for I := 0 to 15 do Result := Result + Digits[(D[I] shr 4) and $0f] + Digits[D[I] and $0f];
end;

// -----------------------------------------------------------------------------------------------

// Compare two Digests
function MD5Match(D1, D2: MD5Digest): boolean;
var
I: byte;
begin
I := 0;
Result := TRUE;
while Result and (I <16) do begin
Result := D1[I] = D2[I];
inc(I);
end;
end;

end.