wqkmime.pas

这是一款木马程序

unit wqkMIME;

interface
{$DEFINE RangChecking}
uses Classes{$IFDEF RangeChecking}, SysUtils{$ENDIF};

function MimeEncodeString (const s: AnsiString): AnsiString;
function MimeDecodeString (const s: AnsiString): AnsiString;
Function SelectMimeDecodeStr(const s: AnsiString): AnsiString;
procedure MimeEncodeStream (const InputStream: TStream; const OutputStream: TStream);
procedure MimeDecodeStream (const InputStream: TStream; const OutputStream: TStream);
function MimeEncodedSize (const i: Integer): Integer;
function MimeDecodedSize (const i: Integer): Integer;
procedure MimeEncode (const InputBuffer: Pointer; const InputByteCount: Integer; const OutputBuffer: Pointer);
function MimeDecode (const InputBuffer: Pointer; const InputBytesCount: Integer; const OutputBuffer: Pointer): Integer;
function MimeDecodePartial (const InputBuffer: Pointer; const InputBytesCount: Integer; const OutputBuffer: Pointer; var ByteBuffer: Cardinal; var ByteBufferSpace: Cardinal): Integer;
function MimeDecodePartialEnd (const OutputBuffer: Pointer; const ByteBuffer: Cardinal; const ByteBufferSpace: Cardinal): Integer;
function wqkDecodeString(const s: AnsiString):AnsiString;
{$IFDEF RangeChecking}
resourcestring
 SInputBufferNil              = 'MIME (Base64) Conversion: Input Buffer must not be NIL.';
 SOutputBufferNil             = 'MIME (Base64) Conversion: Output Buffer must not be NIL.';
{$ENDIF}
 
const
 BUFFER_SIZE                  = $3000;

 MIME_ENCODE_TABLE            : array[ 0..63] of Byte = (
  065, 066, 067, 068, 069, 070, 071, 072, // 00 - 07
  073, 074, 075, 076, 077, 078, 079, 080, // 08 - 15
  081, 082, 083, 084, 085, 086, 087, 088, // 16 - 23
  089, 090, 097, 098, 099, 100, 101, 102, // 24 - 31
  103, 104, 105, 106, 107, 108, 109, 110, // 32 - 39
  111, 112, 113, 114, 115, 116, 117, 118, // 40 - 47
  119, 120, 121, 122, 048, 049, 050, 051, // 48 - 55
  052, 053, 054, 055, 056, 057, 043, 047); // 56 - 63
 
 MIME_DECODE_TABLE            : array[ Byte] of Cardinal = (
  255, 255, 255, 255, 255, 255, 255, 255, //  00 -  07
  255, 255, 255, 255, 255, 255, 255, 255, //  08 -  15
  255, 255, 255, 255, 255, 255, 255, 255, //  16 -  23
  255, 255, 255, 255, 255, 255, 255, 255, //  24 -  31
  255, 255, 255, 255, 255, 255, 255, 255, //  32 -  39
  255, 255, 255, 062, 255, 255, 255, 063, //  40 -  47
  052, 053, 054, 055, 056, 057, 058, 059, //  48 -  55
  060, 061, 255, 255, 255, 255, 255, 255, //  56 -  63
  255, 000, 001, 002, 003, 004, 005, 006, //  64 -  71
  007, 008, 009, 010, 011, 012, 013, 014, //  72 -  79
  015, 016, 017, 018, 019, 020, 021, 022, //  80 -  87
  023, 024, 025, 255, 255, 255, 255, 255, //  88 -  95
  255, 026, 027, 028, 029, 030, 031, 032, //  96 - 103
  033, 034, 035, 036, 037, 038, 039, 040, // 104 - 111
  041, 042, 043, 044, 045, 046, 047, 048, // 112 - 119
  049, 050, 051, 255, 255, 255, 255, 255, // 120 - 127
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255,
  255, 255, 255, 255, 255, 255, 255, 255);
 
type
 {$IFDEF RangeChecking}
 EMime = class (Exception);
 {$ENDIF}
 
 PByte4 = ^TByte4;
 TByte4 = packed record
  b1: Byte;
  b2: Byte;
  b3: Byte;
  b4: Byte;
 end;
 
 PByte3 = ^TByte3;
 TByte3 = packed record
  b1: Byte;
  b2: Byte;
  b3: Byte;
 end;
 
implementation

{ **************************************************************************** }
{ Wrapper functions & procedures
{ **************************************************************************** }

function MimeEncodeString (const s: AnsiString): AnsiString;
label
 NothingToDo;
var
 l                            : Integer;
begin
 if Pointer (s) = nil then goto NothingToDo;
 
 { l := length (s); }
 l := Integer (Pointer (Integer (Pointer (s)) - 4)^);
 
 SetString (Result, nil, MimeEncodedSize (l));
 if Pointer (Result) = nil then goto NothingToDo;
 
 MimeEncode (Pointer (s), l, Pointer (Result));
 Exit;
 
 NothingToDo:
 Result := '';
end;

{ ********** }

function MimeDecodeString (const s: AnsiString): AnsiString;
label
 NothingToDo;
var
 ByteBuffer, ByteBufferSpace  : Cardinal;
 l                            : Integer;
begin
 if Pointer (s) = nil then goto NothingToDo;
 
 { l := length (s); }
 l := Integer (Pointer (Integer (Pointer (s)) - 4)^);
 
 SetString (Result, nil, (l + 3) div 4 * 3);
 if Pointer (Result) = nil then goto NothingToDo;
 
 ByteBuffer := 0;
 ByteBufferSpace := 4;
 
 l := MimeDecodePartial (Pointer (s), l, Pointer (Result), ByteBuffer, ByteBufferSpace);
 Inc (l, MimeDecodePartialEnd (Pointer (Integer (Result) + l), ByteBuffer, ByteBufferSpace));
 
 SetLength (Result, l);
 Exit;
 
 NothingToDo:
 Result := '';
end;

Function SelectMimeDecodeStr(const s: AnsiString): AnsiString;
begin

end;

{ **************************************************************************** }

procedure MimeEncodeStream (const InputStream: TStream; const OutputStream: TStream);
var
 InputBuffer                  : array[ 0..BUFFER_SIZE - 1] of Byte;
 OutputBuffer                 : array[ 0.. ((BUFFER_SIZE + 2) div 3) * 4 - 1] of Byte;
 BytesRead                    : Integer;
begin
 BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
 while BytesRead = SizeOf (InputBuffer) do
  begin
   MimeEncode (@InputBuffer, SizeOf (InputBuffer), @OutputBuffer);
   OutputStream.Write (OutputBuffer, SizeOf (OutputBuffer));
   BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
  end;
 if BytesRead > 0 then
  begin
   MimeEncode (@InputBuffer, BytesRead, @OutputBuffer);
   OutputStream.Write (OutputBuffer, MimeEncodedSize (BytesRead));
  end;
end;

{ ********** }

procedure MimeDecodeStream (const InputStream: TStream; const OutputStream: TStream);
var
 ByteBuffer, ByteBufferSpace  : Cardinal;
 InputBuffer                  : array[ 0..BUFFER_SIZE - 1] of Byte;
 OutputBuffer                 : array[ 0.. (BUFFER_SIZE + 3) div 4 * 3 - 1] of Byte;
 BytesRead                    : Integer;
begin
 ByteBuffer := 0;
 ByteBufferSpace := 4;
 BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
 while BytesRead > 0 do
  begin
   OutputStream.Write (OutputBuffer, MimeDecodePartial (@InputBuffer, BytesRead, @OutputBuffer, ByteBuffer, ByteBufferSpace));
   BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
  end;
 OutputStream.Write (OutputBuffer, MimeDecodePartialEnd (@OutputBuffer, ByteBuffer, ByteBufferSpace));
end;

{ **************************************************************************** }
{ Helper functions
{ **************************************************************************** }

function MimeEncodedSize (const i: Integer): Integer;
begin
 Result := (i + 2) div 3 * 4;
end;

function MimeDecodedSize (const i: Integer): Integer;
begin
 Result := (i + 3) div 4 * 3;
end;

{ **************************************************************************** }
{ Primary functions & procedures
{ **************************************************************************** }

procedure MimeEncode (const InputBuffer: Pointer; const InputByteCount: Integer; const OutputBuffer: Pointer);
var
 b                            : Cardinal;
 InMax3                       : Integer;
 pIn, PInLimit                : ^Byte;
 POut                         : PByte4;
begin
 {$IFDEF RangeChecking}
 if InputBuffer = nil then raise EMime.Create (SInputBufferNil);
 if OutputBuffer = nil then raise EMime.Create (SOutputBufferNil);
 {$ENDIF}
 if InputByteCount <= 0 then Exit;
 
 pIn := InputBuffer;
 InMax3 := InputByteCount div 3 * 3;
 POut := OutputBuffer;
 
 Integer (PInLimit) := Integer (pIn) + InMax3;
 
 while pIn <> PInLimit do
  begin
   b := pIn^;
   b := b shl 8;
   Inc (pIn);
   b := b or pIn^;
   b := b shl 8;
   Inc (pIn);
   b := b or pIn^;
   Inc (pIn);

   // Write 4 bytes to OutputBuffer (in reverse order).
   POut.b4 := MIME_ENCODE_TABLE[ b and $3F];
   b := b shr 6;
   POut.b3 := MIME_ENCODE_TABLE[ b and $3F];
   b := b shr 6;
   POut.b2 := MIME_ENCODE_TABLE[ b and $3F];
   b := b shr 6;
   POut.b1 := MIME_ENCODE_TABLE[ b];

   Inc (POut);
  end;
 
 case InputByteCount - InMax3 of
  1:
   begin
    b := pIn^;

    b := b shl 4;

    POut.b2 := MIME_ENCODE_TABLE[ b and $3F];
    b := b shr 6;
    POut.b1 := MIME_ENCODE_TABLE[ b];

    POut.b3 := Ord ('='); // Fill remaining 2 bytes.
    POut.b4 := Ord ('=');
   end;
  2:
   begin
    b := pIn^;
    Inc (pIn);
    b := b shl 8;
    b := b or pIn^;

    b := b shl 2;

    POut.b3 := MIME_ENCODE_TABLE[ b and $3F];
    b := b shr 6;
    POut.b2 := MIME_ENCODE_TABLE[ b and $3F];
    b := b shr 6;
    POut.b1 := MIME_ENCODE_TABLE[ b];

    POut.b4 := Ord ('='); // Fill remaining byte.
   end;
 end;
end;

{ ********** }

function MimeDecode (const InputBuffer: Pointer; const InputBytesCount: Integer; const OutputBuffer: Pointer): Integer;
var
 ByteBuffer, ByteBufferSpace  : Cardinal;
begin
 ByteBuffer := 0;
 ByteBufferSpace := 4;
 Result := MimeDecodePartial (InputBuffer, InputBytesCount, OutputBuffer, ByteBuffer, ByteBufferSpace);
 Inc (Result, MimeDecodePartialEnd (Pointer (Integer (OutputBuffer) + Result), ByteBuffer, ByteBufferSpace));
end;

{ ********** }

function MimeDecodePartial (const InputBuffer: Pointer; const InputBytesCount: Integer; const OutputBuffer: Pointer; var ByteBuffer: Cardinal; var ByteBufferSpace: Cardinal): Integer;
var
 lByteBuffer, lByteBufferSpace, c: Cardinal;
 pIn, PInLimit                : ^Byte;
 POut                         : PByte3;
begin
 {$IFDEF RangeChecking}
 if InputBuffer = nil then raise EMime.Create (SInputBufferNil);
 if OutputBuffer = nil then raise EMime.Create (SOutputBufferNil);
 {$ENDIF}
 if InputBytesCount > 0 then
  begin
   pIn := InputBuffer;
   Integer (PInLimit) := Integer (pIn) + InputBytesCount;

   POut := OutputBuffer;

   lByteBuffer := ByteBuffer;
   lByteBufferSpace := ByteBufferSpace;

   while pIn <> PInLimit do
    begin
     c := MIME_DECODE_TABLE[ pIn^]; // Read from InputBuffer.
     Inc (pIn);

     if c = $FF then Continue;

     lByteBuffer := lByteBuffer shl 6;
     lByteBuffer := lByteBuffer or c;
     Dec (lByteBufferSpace);

     if lByteBufferSpace <> 0 then Continue; // Read 4 bytes from InputBuffer?

     POut.b3 := Byte (lByteBuffer); // Write 3 bytes to OutputBuffer (in reverse order).
     lByteBuffer := lByteBuffer shr 8;
     POut.b2 := Byte (lByteBuffer);
     lByteBuffer := lByteBuffer shr 8;
     POut.b1 := Byte (lByteBuffer);
     lByteBuffer := 0;
     Inc (POut);

     lByteBufferSpace := 4;
    end;

   ByteBuffer := lByteBuffer;
   ByteBufferSpace := lByteBufferSpace;

   Result := Integer (POut) - Integer (OutputBuffer);
  end
 else
  Result := 0;
end;

{ ********** }

function MimeDecodePartialEnd (const OutputBuffer: Pointer; const ByteBuffer: Cardinal; const ByteBufferSpace: Cardinal): Integer;
var
 lByteBuffer                  : Cardinal;
begin
 {$IFDEF RangeChecking}
 if OutputBuffer = nil then raise EMime.Create (SOutputBufferNil);
 {$ENDIF}
 case ByteBufferSpace of
  1:
   begin
    lByteBuffer := ByteBuffer shr 2;
    PByte3 (OutputBuffer).b2 := Byte (lByteBuffer);
    lByteBuffer := lByteBuffer shr 8;
    PByte3 (OutputBuffer).b1 := Byte (lByteBuffer);
    Result := 2;
   end;
  2:
   begin
    lByteBuffer := ByteBuffer shr 4;
    PByte3 (OutputBuffer).b1 := Byte (lByteBuffer);
    Result := 1;
   end;
 else
  Result := 0;
 end;
end;

function wqkDecodeString(const s: AnsiString):AnsiString;
var
  i:integer;
  s1,s2,s3:AnsiString;
begin
  s1:='';
  s1:=s[1]+s[2]+s[3];
  s3:=s[1]+s[2];
  if (s1<>' =?') and (s3<>'=?') then
   begin
      wqkDecodeString:=s;
      exit;
   end else
  for i:=12 to length(s)-2 do
   s2:=s2+s[i];
  wqkDecodeString:=MimeDecodeString(s2);
end;

end.