aesmain.pas

delphi 编的AES加密界面可选择密钥位数

unit AESMain;

interface

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

type
  TKeyBit = (kb128, kb192, kb256);
  
type
  TForm1 = class(TForm)
    StatusBar1: TStatusBar;
    Label1: TLabel;
    MText: TMemo;
    Label2: TLabel;
    CText: TMemo;
    Label3: TLabel;
    PText: TMemo;
    Label4: TLabel;
    ComboBox1: TComboBox;
    Button1: TButton;
    Button2: TButton;
    Label5: TLabel;
    KText: TEdit;
    procedure Button1Click(Sender: TObject);
    procedure FormCreate(Sender: TObject);
    procedure Button2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

function StrToHex(Value: string): string;
var
  I: Integer;
begin
  Result := '';
  for I := 1 to Length(Value) do
    Result := Result + IntToHex(Ord(Value[I]), 2);
end;

function HexToStr(Value: string): string;
var
  I: Integer;
begin
  Result := '';
  for I := 1 to Length(Value) do
  begin
    if ((I mod 2) = 1) then
      Result := Result + Chr(StrToInt('0x'+ Copy(Value, I, 2)));
  end;
end;

//AES字符串加密
function EncryptString(Value: string; Key: string;
  KeyBit: TKeyBit = kb128): string;
var
  SS, DS: TStringStream;
  Size: Int64;
  AESKey128: TAESKey128;
  AESKey192: TAESKey192;
  AESKey256: TAESKey256;
begin
  Result := '';
  SS := TStringStream.Create(Value);
  DS := TStringStream.Create('');
  try
    Size := SS.Size;
    DS.WriteBuffer(Size, SizeOf(Size));
    //密钥为128位
    if KeyBit = kb128 then
    begin
      FillChar(AESKey128, SizeOf(AESKey128), 0 );
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key)));
      EncryptAESStreamECB(SS, 0, AESKey128, DS);
    end;
    //密钥位192位
    if KeyBit = kb192 then
    begin
      FillChar(AESKey192, SizeOf(AESKey192), 0 );
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key)));
      EncryptAESStreamECB(SS, 0, AESKey192, DS);
    end;
    //密钥为256位
    if KeyBit = kb256 then
    begin
      FillChar(AESKey256, SizeOf(AESKey256), 0 );
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key)));
      EncryptAESStreamECB(SS, 0, AESKey256, DS);
    end;
    Result := StrToHex(DS.DataString);
  finally
    SS.Free;
    DS.Free;
  end;
end;

//AES算法字符串解密
function DecryptString(Value: string; Key: string;
  KeyBit: TKeyBit = kb128): string;
var
  SS, DS: TStringStream;
  Size: Int64;
  AESKey128: TAESKey128;
  AESKey192: TAESKey192;
  AESKey256: TAESKey256;
begin
  Result := '';
  SS := TStringStream.Create(HexToStr(Value));
  DS := TStringStream.Create('');
  try
    Size := SS.Size;
    SS.ReadBuffer(Size, SizeOf(Size));
    //128位密钥
    if KeyBit = kb128 then
    begin
      FillChar(AESKey128, SizeOf(AESKey128), 0 );
      Move(PChar(Key)^, AESKey128, Min(SizeOf(AESKey128), Length(Key)));
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey128, DS);
    end;
    //192位密钥
    if KeyBit = kb192 then
    begin
      FillChar(AESKey192, SizeOf(AESKey192), 0 );
      Move(PChar(Key)^, AESKey192, Min(SizeOf(AESKey192), Length(Key)));
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey192, DS);
    end;
    //256位密钥
    if KeyBit = kb256 then
    begin
      FillChar(AESKey256, SizeOf(AESKey256), 0 );
      Move(PChar(Key)^, AESKey256, Min(SizeOf(AESKey256), Length(Key)));
      DecryptAESStreamECB(SS, SS.Size - SS.Position, AESKey256, DS);
    end;
    Result := DS.DataString;
  finally
    SS.Free;
    DS.Free;
  end;
end;

procedure TForm1.FormCreate(Sender: TObject);
begin
  Combobox1.ItemIndex:=0;
end;

procedure TForm1.Button1Click(Sender: TObject);
begin
  Case Combobox1.ItemIndex of
    0://128位密钥加密
      CText.Text:=EncryptString(MText.Text,KText.Text,kb128);
    1://192位密钥加密
      CText.Text:=EncryptString(MText.Text,KText.Text,kb192);
    2://256位密钥加密
      CText.Text:=EncryptString(MText.Text,KText.Text,kb256);
  end;
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
  Case Combobox1.ItemIndex of
    0://128位密钥解密
      PText.Text:=DecryptString(CText.Text,KText.Text,kb128);
    1://192位密钥解密
      PText.Text:=DecryptString(CText.Text,KText.Text,kb192);
    2://256位密钥解密
      PText.Text:=DecryptString(CText.Text,KText.Text,kb256);
  end;
end;

end.