descrypt.pas

参照上兴、鸽子等源码编写编写出来的。 编译环境：Delphi7+SP+DP+indy9等控件

unit DESCrypt;

interface
uses
  SysUtils,Classes;
function StrDecrypt(str: string): string;
implementation


function StrDecrypt(str: string): string;
var
  X, Y: Integer;
  A: Byte;
  Key: string;
begin
  Key := '123456789'; //注意了,這裡要和加密鑰匙一樣.
  Y := 1;
  for X := 1 to Length(Str) do
  begin
    A := (ord(Str[X]) and $0F) xor (ord(Key[Y]) and $0F);
    Str[X] := char((ord(Str[X]) and $F0) + A);
    Inc(Y);
    if Y > length(Key) then Y := 1;
  end;
  Result := Str;
end;
end.