使用blowfish加解密

unit Unit1;

interface

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

type
  TForm1 = class(TForm)
    Button1: TButton;
    procedure Button1Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;
  g_LibHandle : THandle ;  // dynamic load library
  BlowfishEncodeString : function(lpszString: PChar; lpszKey: PChar;lpszBuffer: PChar; dwBufferSize: DWORD): DWORD; stdcall ;
  BlowfishDecodeString : function(lpszEncodedString: PChar; lpszKey: PChar;lpszBuffer: PChar; dwBufferSize: DWORD): DWORD; stdcall ;
  CalcCrc32 : function(pBuffer: Pointer; dwBufferSize: DWORD): DWORD; stdcall ;
  //加解密
  function  EncrypBlowfishPassword(sPassword    : String): String; //傳入欲加密字串,傳回加密後的字串  {Blowfish}
  function  DecrypBlowfishPassword(sEncrypedPWD : String): String; //傳入加密過的密碼,傳回解密後的明文密碼 {Blowfish}
const
  _BLOWFISH_KEY               = 'FORT_BLOWFISH_KEY';  //使用BlowFish 加密的Key

implementation

{$R *.dfm}
//----------------------------------------------------------------------------//
// LoadAllLibrary 載入所需Dll                                                 //
//                傳回值 :  TRUE  載入成功                                    //
//                          False 載入失敗                                    //
//----------------------------------------------------------------------------//
function  LoadAllLibrary():boolean ;
var
  sPathName :string ;
begin
  Result := true ;
  sPathName := 'C:\facrypto.dll' ;
  g_LibHandle  := LoadLibrary(PAnsiChar(sPathName)) ;
  if( g_LibHandle = 0 ) then
  begin
    showmessage('載入 DLL 發生錯誤');
    Result := false ;
    Exit ;
  end ;

  //加密
  @BlowfishEncodeString := GetprocAddress( g_LibHandle, 'BlowfishEncodeString') ;

  //解密
  @BlowfishDecodeString := GetprocAddress( g_LibHandle, 'BlowfishDecodeString') ;

  //CRC32
  @CalcCrc32 := GetprocAddress( g_LibHandle, 'CalcCrc32') ;

  //若三者有一出錯,即傳回False
  if( (@BlowfishEncodeString=NIL) OR (@BlowfishDecodeString=NIL) OR (@CalcCrc32=NIL) ) then
  begin
    showmessage('載入 DLL 發生錯誤');
    Result := false ;
    Exit ;
  end ;
end ;

procedure FreeAllLibrary() ;
begin
  FreeLibrary(g_LibHandle) ;
end ;

//----------------------------------------------------------------------------//
// EncrypBlowfishPassword 加密欲加密的密碼                                    //
//                        參數 : 明文字串                                     //
//                        傳回值 : 加密後的字串                               //
//----------------------------------------------------------------------------//
function  EncrypBlowfishPassword(sPassword    : String): String;
var
  cEncrypt : array[0..255] of Char;

begin

  try
    { encrypt } // 欲加密字串, 加密參數 ,加密後的秘文,buffer長度
    BlowfishEncodeString( PChar(sPassword), PChar(_BLOWFISH_KEY),cEncrypt, 256) ;

    //轉回字串後傳回
    Result := string(cEncrypt);
  except
    //InfoMsgBox('Encryp Error!!');
    Exit;
  end;

end;

//----------------------------------------------------------------------------//
// DecrypBlowfishPassword 解開被加密後的密文                                  //
//                        參數 : 密文字串                                     //
//                        傳回值 : 解密後的明文字串                           //
//----------------------------------------------------------------------------//
function  DecrypBlowfishPassword(sEncrypedPWD : String): String;
var
  cDecrypt : array[0..255] of Char;

begin

  try
    //解密
    BlowfishDecodeString(PChar(sEncrypedPWD),PChar(_BLOWFISH_KEY), cDecrypt,255) ;

    //轉回字串後 傳回
    Result := string(cDecrypt);
  except
    //InfoMsgBox('Decry Error!!');
    exit;
  end;

end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  if not LoadAllLibrary() then
  begin
    showmessage('Error occurred while loading library') ;
    exit;
  end ;
  caption := EncrypBlowfishPassword('kobe');
  FreeAllLibrary() ;  // free all library
end;

end.