delphi MD5Unit.pas

unit MD5Unit; 
 
interface 
 
uses 
  SysUtils, 
  windows, 
  Classes; 
  function transfer(tran:widestring):widestring ; 
  function GetCode(Afilename:String):String;   
implementation 
 
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; 
 
 
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; 
 
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; 
 
 
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; 
 
 
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; 
 
 
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; 
 
 
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; 
 
 
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; 
 
 
function MD5String(M: string): MD5Digest;stdcall; 
var 
	Context: MD5Context; 
begin 
	MD5Init(Context); 
	MD5Update(Context, pChar(M), length(M)); 
	MD5Final(Context, Result); 
end; 
 
function MD5Print(D: MD5Digest): string;stdcall; 
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; 
 
 
function transfer(tran:widestring):widestring ; 
begin 
    Result:=md5print(md5string(tran)); 
end; 
 
function GetCode(Afilename:String):String; 
var 
  fs:TFileStream; 
  ss:TStringStream; 
begin 
    fs:=TFileStream.Create(Afilename,OF_READ); 
    ss:=TStringStream.Create(''); 
    ss.WriteString(IntToStr(fs.Size)); 
    if fs.Size>5*1024*1024 then begin 
      ss.CopyFrom(fs,2*1024*1024); 
      fs.Position:=fs.Position-2*1024*1024-1; 
      ss.CopyFrom(fs,2*1024*1024); 
    end else begin 
      ss.CopyFrom(fs,0); 
    end; 
    Result:=transfer(ss.DataString); 
    ss.free; 
    fs.Free; 
end; 
 
end.