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 < Length do begin
  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] <