DELPHI使用AES加解密密碼

這通常是運用在資料庫內有密碼的時候，不希望顯示的是明碼，所以要透過加密解密的動作來實現這個需求，這邊使用的是AES加密功能。

DELPHI 用的 AES 檔案 下載

此範例程式(D7)已含AES檔案：下載

程式執行：

將字串加密

將字串解密還原

將 28295_AESDemo.zip 解壓縮後三個檔案
ElAES.dcu
ElAES.pas
ElAES.txt
COPY 欲撰寫程式的同一目錄下面

將(ElAES, Math) USES進程式

unit hoststatus;

interface

uses
    ……….ElAES, Math;

//AES加解密用到的 Function ===========================
function Tform1.StringToHex(S: string): string;
var
    i: integer;

begin
  Result := ”;

  // Go throught every single characters, and convert them
  // to hexadecimal…
    for i := 1 to Length( S ) do
      Result := Result + IntToHex( Ord( S[i] ), 2 );
end;

function Tform1.HexToString(S: string): string;
var
    i: integer;

begin
  Result := ”;

  // Go throught every single hexadecimal characters, and convert
  // them to ASCII characters…
  for i := 1 to Length( S ) do
  begin
    // Only process chunk of 2 digit Hexadecimal…
      if ((i mod 2) = 1) then
          Result := Result + Chr( StrToInt( ‘0x’ + Copy( S, i, 2 )));
  end;
end;

//AES加密Function
function Tform1.Encrypt(Passwd: String): String;
var
  Source: TStringStream;
  Dest: TStringStream;
  Start, Stop: cardinal;
  Size: integer;
  Key: TAESKey128;
  PWD: String;
begin
  //設定加密密碼;
  PWD := ‘/.,mnbvcxz’;

  Source := TStringStream.Create( Passwd );
  Dest   := TStringStream.Create( ” );

  try
    // Save data to memory stream…
    Size := Source.Size;
    Dest.WriteBuffer( Size, SizeOf(Size) );

    // Prepare key…
    FillChar( Key, SizeOf(Key), 0 );
    Move( PChar(PWD)^, Key, Min( SizeOf( Key ), Length( PWD )));

    // Start encryption…
    Start := GetTickCount;
    EncryptAESStreamECB( Source, 0, Key, Dest );
    Stop := GetTickCount;

    // Display encrypted text using hexadecimals…
    Result := StringToHex( Dest.DataString );

  finally
    Source.Free;
    Dest.Free;
  end;
end;

//AES解密Function
function Tform1.Decypt(Passwd: String): String;
var
  Source: TStringStream;
  Dest: TStringStream;
  Start, Stop: cardinal;
  Size: integer;
  Key: TAESKey128;
  EncryptedText: TStrings;
  S: string;
  PWD: String;
begin
  //設定加密密碼;
  PWD := ‘/.,mnbvcxz’;

  // Convert hexadecimal to a strings before decrypting…
  Source := TStringStream.Create( HexToString( Passwd ));
  Dest   := TStringStream.Create( ” );

  try
    // Start decryption…
    Size := Source.Size;
    Start := GetTickCount;
    Source.ReadBuffer(Size, SizeOf(Size));

    // Prepare key…
    FillChar(Key, SizeOf(Key), 0);
    Move(PChar(PWD)^, Key, Min(SizeOf(Key), Length(PWD)));

    // Decrypt now…
    DecryptAESStreamECB(Source, Source.Size – Source.Position, Key, Dest);
    Stop := GetTickCount;

    // Display unencrypted text…
    Result := Dest.DataString;

  finally
    Source.Free;
    Dest.Free;
  end;
end;
//AES加解密用到的 Function ===========================

procedure TForm1.Button1Click(Sender: TObject);
begin
  //showmessage(Encrypt(Edit1.Text));
  Memo1.Text:= Encrypt(Edit1.Text);
  Memo2.Text:=”;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  if Trim(Memo1.Text) <> ” then
  begin
    //showmessage(Decypt(Memo1.Text));
    Memo2.Text:= Decypt(Memo1.Text);
  end else
    MessageDlg(‘沒有已加密資料可供解密!’, mtError, [mbOk], 0);
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Memo1.Enabled := false;
  Memo2.Enabled := false;
end;