_decode.pas

传世源码可编译的,功能齐全.是学习的好模版,会DELPHI的朋友们也可以自己修改,弄个自己的引擎.

{*******************************************************}
{                                                       }
{       封包加密解密                                    }
{                                                       }
{       版权所有 (C) 2006 JDboy                         }
{                                                       }
{*******************************************************}


unit _Decode;

interface

uses
  Windows, Messages, SysUtils,Classes;
  
{DES Function Start}
type
  TKeyByte = array[0..5] of Byte;
  TDesMode = (dmEncry, dmDecry);

function EncryStr(Str, Key: String): String;
function DecryStr(Str, Key: String): String;
function EncryStrHex(Str, Key: String): String;
function DecryStrHex(StrHex, Key: String): String;
{DES Function End}
function My_Encode(Str,Key:string):string;
Function My_Decode(str,Key:string):string;
{Base64 Function Start}
function MimeEncodeString (const s: AnsiString): AnsiString;
function MimeEncodeStringNoCRLF (const s: AnsiString): AnsiString;
function MimeDecodeString (const s: AnsiString): AnsiString;
procedure MimeEncodeStream (const InputStream: TStream; const OutputStream: TStream);
procedure MimeEncodeStreamNoCRLF (const InputStream: TStream; const OutputStream: TStream);
procedure MimeDecodeStream (const InputStream: TStream; const OutputStream: TStream);
function MimeEncodedSize (const i: Cardinal): Cardinal;
function MimeEncodedSizeNoCRLF (const i: Cardinal): Cardinal;
function MimeDecodedSize (const i: Cardinal): Cardinal;
procedure DecodeHttpBasicAuthentication (const BasicCredentials: AnsiString;
  out UserId, PassWord: AnsiString);
procedure MimeEncode (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
procedure MimeEncodeNoCRLF (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
procedure MimeEncodeFullLines (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
function MimeDecode (const InputBuffer; const InputBytesCount: Cardinal; out OutputBuffer): Cardinal;
function MimeDecodePartial (const InputBuffer; const InputBytesCount: Cardinal;
  out OutputBuffer; var ByteBuffer: Cardinal; var ByteBufferSpace: Cardinal): Cardinal;
function MimeDecodePartialEnd (out OutputBuffer; const ByteBuffer: Cardinal;
  const ByteBufferSpace: Cardinal): Cardinal;
procedure Base64Encode(InputFile, OutputFile: string);
procedure Base64Decode(InputFile, OutputFile: string);
const
 MIME_ENCODED_LINE_BREAK = 76;
 MIME_DECODED_LINE_BREAK = MIME_ENCODED_LINE_BREAK div 4 * 3;
 BUFFER_SIZE        = MIME_DECODED_LINE_BREAK * 3 * 4 * 16;
 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_PAD_CHAR      = Byte ('=');

 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);
  BitIP: array[0..63] of Byte =   //初始值置IP
    (57, 49, 41, 33, 25, 17,  9,  1,
     59, 51, 43, 35, 27, 19, 11,  3,
     61, 53, 45, 37, 29, 21, 13,  5,
     63, 55, 47, 39, 31, 23, 15,  7,
     56, 48, 40, 32, 24, 16,  8,  0,
     58, 50, 42, 34, 26, 18, 10,  2,
     60, 52, 44, 36, 28, 20, 12,  4,
     62, 54, 46, 38, 30, 22, 14,  6 );

  BitCP: array[0..63] of Byte = //逆初始置IP-1
    ( 39,  7, 47, 15, 55, 23, 63, 31,
      38,  6, 46, 14, 54, 22, 62, 30,
      37,  5, 45, 13, 53, 21, 61, 29,
      36,  4, 44, 12, 52, 20, 60, 28,
      35,  3, 43, 11, 51, 19, 59, 27,
      34,  2, 42, 10, 50, 18, 58, 26,
      33,  1, 41,  9, 49, 17, 57, 25,
      32,  0, 40,  8, 48, 16, 56, 24 );

  BitExp: array[0..47] of Integer = // 位选择函数E
    ( 31, 0, 1, 2, 3, 4, 3, 4, 5, 6, 7, 8, 7, 8, 9,10,
      11,12,11,12,13,14,15,16,15,16,17,18,19,20,19,20,
      21,22,23,24,23,24,25,26,27,28,27,28,29,30,31,0  );

  BitPM: array[0..31] of Byte =  //置换函数P
    ( 15, 6,19,20,28,11,27,16, 0,14,22,25, 4,17,30, 9,
       1, 7,23,13,31,26, 2, 8,18,12,29, 5,21,10, 3,24 );

  sBox: array[0..7] of array[0..63] of Byte =    //S盒
    ( ( 14,  4, 13,  1,  2, 15, 11,  8,  3, 10,  6, 12,  5,  9,  0,  7,
         0, 15,  7,  4, 14,  2, 13,  1, 10,  6, 12, 11,  9,  5,  3,  8,
         4,  1, 14,  8, 13,  6,  2, 11, 15, 12,  9,  7,  3, 10,  5,  0,
        15, 12,  8,  2,  4,  9,  1,  7,  5, 11,  3, 14, 10,  0,  6, 13 ),

      ( 15,  1,  8, 14,  6, 11,  3,  4,  9,  7,  2, 13, 12,  0,  5, 10,
         3, 13,  4,  7, 15,  2,  8, 14, 12,  0,  1, 10,  6,  9, 11,  5,
         0, 14,  7, 11, 10,  4, 13,  1,  5,  8, 12,  6,  9,  3,  2, 15,
        13,  8, 10,  1,  3, 15,  4,  2, 11,  6,  7, 12,  0,  5, 14,  9 ),

      ( 10,  0,  9, 14,  6,  3, 15,  5,  1, 13, 12,  7, 11,  4,  2,  8,
        13,  7,  0,  9,  3,  4,  6, 10,  2,  8,  5, 14, 12, 11, 15,  1,
        13,  6,  4,  9,  8, 15,  3,  0, 11,  1,  2, 12,  5, 10, 14,  7,
         1, 10, 13,  0,  6,  9,  8,  7,  4, 15, 14,  3, 11,  5,  2, 12 ),

      (  7, 13, 14,  3,  0,  6,  9, 10,  1,  2,  8,  5, 11, 12,  4, 15,
        13,  8, 11,  5,  6, 15,  0,  3,  4,  7,  2, 12,  1, 10, 14,  9,
        10,  6,  9,  0, 12, 11,  7, 13, 15,  1,  3, 14,  5,  2,  8,  4,
         3, 15,  0,  6, 10,  1, 13,  8,  9,  4,  5, 11, 12,  7,  2, 14 ),

      (  2, 12,  4,  1,  7, 10, 11,  6,  8,  5,  3, 15, 13,  0, 14,  9,
        14, 11,  2, 12,  4,  7, 13,  1,  5,  0, 15, 10,  3,  9,  8,  6,
         4,  2,  1, 11, 10, 13,  7,  8, 15,  9, 12,  5,  6,  3,  0, 14,
        11,  8, 12,  7,  1, 14,  2, 13,  6, 15,  0,  9, 10,  4,  5,  3 ),

      ( 12,  1, 10, 15,  9,  2,  6,  8,  0, 13,  3,  4, 14,  7,  5, 11,
        10, 15,  4,  2,  7, 12,  9,  5,  6,  1, 13, 14,  0, 11,  3,  8,
         9, 14, 15,  5,  2,  8, 12,  3,  7,  0,  4, 10,  1, 13, 11,  6,
         4,  3,  2, 12,  9,  5, 15, 10, 11, 14,  1,  7,  6,  0,  8, 13 ),

      (  4, 11,  2, 14, 15,  0,  8, 13,  3, 12,  9,  7,  5, 10,  6,  1,
        13,  0, 11,  7,  4,  9,  1, 10, 14,  3,  5, 12,  2, 15,  8,  6,
         1,  4, 11, 13, 12,  3,  7, 14, 10, 15,  6,  8,  0,  5,  9,  2,
         6, 11, 13,  8,  1,  4, 10,  7,  9,  5,  0, 15, 14,  2,  3, 12 ),

      ( 13,  2,  8,  4,  6, 15, 11,  1, 10,  9,  3, 14,  5,  0, 12,  7,
         1, 15, 13,  8, 10,  3,  7,  4, 12,  5,  6, 11,  0, 14,  9,  2,
         7, 11,  4,  1,  9, 12, 14,  2,  0,  6, 10, 13, 15,  3,  5,  8,
         2,  1, 14,  7,  4, 10,  8, 13, 15, 12,  9,  0,  3,  5,  6, 11 ) );

  BitPMC1: array[0..55] of Byte = //选择置换PC-1
    ( 56, 48, 40, 32, 24, 16,  8,
       0, 57, 49, 41, 33, 25, 17,
       9,  1, 58, 50, 42, 34, 26,
      18, 10,  2, 59, 51, 43, 35,
      62, 54, 46, 38, 30, 22, 14,
       6, 61, 53, 45, 37, 29, 21,
      13,  5, 60, 52, 44, 36, 28,
      20, 12,  4, 27, 19, 11,  3 );

  BitPMC2: array[0..47] of Byte =//选择置换PC-2 
    ( 13, 16, 10, 23,  0,  4,
       2, 27, 14,  5, 20,  9,
      22, 18, 11,  3, 25,  7,
      15,  6, 26, 19, 12,  1,
      40, 51, 30, 36, 46, 54,
      29, 39, 50, 44, 32, 47,
      43, 48, 38, 55, 33, 52,
      45, 41, 49, 35, 28, 31 );

type
 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;
{Base64 Function End}

var
 subKey: array[0..15] of TKeyByte;
implementation
//..........................Base64 Start
function MimeEncodeString (const s: AnsiString): AnsiString;
var
 l                  : Cardinal;
begin
 if Pointer (s) <> nil then
  begin
   l := Cardinal (Pointer (Cardinal (s) - 4)^);
   SetLength (Result, MimeEncodedSize (l));
   MimeEncode (Pointer (s)^, l, Pointer (Result)^);
  end
 else
  Result := '';
end;

function MimeEncodeStringNoCRLF (const s: AnsiString): AnsiString;
var
 l                  : Cardinal;
begin
 if Pointer (s) <> nil then
  begin
   l := Cardinal (Pointer (Cardinal (s) - 4)^);
   SetLength (Result, MimeEncodedSizeNoCRLF (l));
   MimeEncodeNoCRLF (Pointer (s)^, l, Pointer (Result)^);
  end
 else
  Result := '';
end;

function MimeDecodeString (const s: AnsiString): AnsiString;
var
 ByteBuffer, ByteBufferSpace: Cardinal;
 l                  : Cardinal;
begin
 if Pointer (s) <> nil then
  begin
   l := Cardinal (Pointer (Cardinal (s) - 4)^);
   SetLength (Result, (l + 3) div 4 * 3);
   ByteBuffer := 0;
   ByteBufferSpace := 4;
   l := MimeDecodePartial (Pointer (s)^, l, Pointer (Result)^, ByteBuffer, ByteBufferSpace);
   Inc (l, MimeDecodePartialEnd (Pointer (Cardinal (Result) + l)^,
     ByteBuffer, ByteBufferSpace));
   SetLength (Result, l);
  end
 else
  Result := '';
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 + BUFFER_SIZE div 
   MIME_DECODED_LINE_BREAK * 2 - 1] of Byte;
 BytesRead : Cardinal;
 IDelta, ODelta : Cardinal;
begin
 BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));

 while BytesRead = SizeOf (InputBuffer) do
  begin
   MimeEncodeFullLines (InputBuffer, SizeOf (InputBuffer), OutputBuffer);
   OutputStream.Write (OutputBuffer, SizeOf (OutputBuffer));
   BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
  end;

 MimeEncodeFullLines (InputBuffer, BytesRead, OutputBuffer);
 
 IDelta := BytesRead div MIME_DECODED_LINE_BREAK; // Number of lines processed.
 ODelta := IDelta * (MIME_ENCODED_LINE_BREAK + 2);
 IDelta := IDelta * MIME_DECODED_LINE_BREAK;
 MimeEncodeNoCRLF(Pointer(Cardinal (@InputBuffer) + IDelta)^, BytesRead - IDelta, 
   Pointer (Cardinal (@OutputBuffer) + ODelta)^);

 OutputStream.Write (OutputBuffer, MimeEncodedSize (BytesRead));
end;

procedure MimeEncodeStreamNoCRLF (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          : Cardinal;
begin
 BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
 while BytesRead = SizeOf (InputBuffer) do
  begin
   MimeEncodeNoCRLF (InputBuffer, SizeOf (InputBuffer), OutputBuffer);
   OutputStream.Write (OutputBuffer, SizeOf (OutputBuffer));
   BytesRead := InputStream.Read (InputBuffer, SizeOf (InputBuffer));
  end;

 MimeEncodeNoCRLF (InputBuffer, BytesRead, OutputBuffer);
 OutputStream.Write (OutputBuffer, (BytesRead + 2) div 3 * 4);
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          : Cardinal;
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;

procedure DecodeHttpBasicAuthentication (const BasicCredentials: AnsiString; out UserId, PassWord: AnsiString);
label
 Fail;
const
 LBasic = 6;                { Length ('Basic ') }
var
 DecodedPtr, p      : PAnsiChar;
 i, l               : Cardinal;
begin
 p := Pointer (BasicCredentials);
 if p = nil then goto Fail;

 l := Cardinal (Pointer (p - 4)^);
 if l <= LBasic then goto Fail;

 Dec (l, LBasic);
 Inc (p, LBasic);

 GetMem (DecodedPtr, (l + 3) div 4 * 3 { MimeDecodedSize (l) });
 l := MimeDecode (p^, l, DecodedPtr^);
 i := 0;
 p := DecodedPtr;
 while (l > 0) and (p[i] <> ':') do
  begin
   Inc (i);
   Dec (l);
  end;
 SetString (UserId, DecodedPtr, i);
 if l > 1 then
  SetString (PassWord, DecodedPtr + i + 1, l - 1)
 else
  PassWord := '';
 
 FreeMem (DecodedPtr);
 Exit;

 Fail:
 UserId := '';
 PassWord := '';
end;

function MimeEncodedSize (const i: Cardinal): Cardinal;
begin
 Result := (i + 2) div 3 * 4 + (i - 1) div MIME_DECODED_LINE_BREAK * 2;
end;

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

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

procedure MimeEncode (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
var
 IDelta, ODelta     : Cardinal;
begin
 MimeEncodeFullLines (InputBuffer, InputByteCount, OutputBuffer);
 IDelta := InputByteCount div MIME_DECODED_LINE_BREAK; 
 ODelta := IDelta * (MIME_ENCODED_LINE_BREAK + 2);
 IDelta := IDelta * MIME_DECODED_LINE_BREAK;
 MimeEncodeNoCRLF (Pointer (Cardinal (@InputBuffer) + IDelta)^,
  InputByteCount - IDelta, Pointer (Cardinal (@OutputBuffer) + ODelta)^);
end;

procedure MimeEncodeFullLines (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
var
 b, OuterLimit      : Cardinal;
 InPtr, InnerLimit  : ^Byte;
 OutPtr             : PByte4;
begin
 if InputByteCount = 0 then Exit;
 InPtr := @InputBuffer;
 OutPtr := @OutputBuffer;

 InnerLimit := InPtr;
 Inc (Cardinal (InnerLimit), MIME_DECODED_LINE_BREAK);

 OuterLimit := Cardinal (InPtr);
 Inc (OuterLimit, InputByteCount);

 while Cardinal (InnerLimit) <= OuterLimit do
  begin

   while InPtr <> InnerLimit do
    begin
     b := InPtr^;
     b := b shl 8;
     Inc (InPtr);
     b := b or InPtr^;
     b := b shl 8;
     Inc (InPtr);
     b := b or InPtr^;
     Inc (InPtr);
     OutPtr^.b4 := MIME_ENCODE_TABLE[b and $3F];
     b := b shr 6;
     OutPtr^.b3 := MIME_ENCODE_TABLE[b and $3F];
     b := b shr 6;
     OutPtr^.b2 := MIME_ENCODE_TABLE[b and $3F];
     b := b shr 6;
     OutPtr^.b1 := MIME_ENCODE_TABLE[b];
     Inc (OutPtr);
    end;
   OutPtr^.b1 := 13;
   OutPtr^.b2 := 10;
   Inc (Cardinal (OutPtr), 2);

   Inc (InnerLimit, MIME_DECODED_LINE_BREAK);
  end;
 
end;

procedure MimeEncodeNoCRLF (const InputBuffer; const InputByteCount: Cardinal; out OutputBuffer);
var
 b, OuterLimit      : Cardinal;
 InPtr, InnerLimit  : ^Byte;
 OutPtr             : PByte4;
begin
 if InputByteCount = 0 then Exit;
 InPtr := @InputBuffer;
 OutPtr := @OutputBuffer;
 
 OuterLimit := InputByteCount div 3 * 3;

 InnerLimit := @InputBuffer;
 Inc (Cardinal (InnerLimit), OuterLimit);
 while InPtr <> InnerLimit do
  begin
   b := InPtr^;
   b := b shl 8;
   Inc (InPtr);
   b := b or InPtr^;
   b := b shl 8;
   Inc (InPtr);
   b := b or InPtr^;
   Inc (InPtr);
   OutPtr^.b4 := MIME_ENCODE_TABLE[b and $3F];
   b := b shr 6;
   OutPtr^.b3 := MIME_ENCODE_TABLE[b and $3F];
   b := b shr 6;
   OutPtr^.b2 := MIME_ENCODE_TABLE[b and $3F];
   b := b shr 6;
   OutPtr^.b1 := MIME_ENCODE_TABLE[b];
   Inc (OutPtr);
  end;
 case InputByteCount - OuterLimit of
  1: