PHP加密算法转换delphi出问题

 function encrypt($string,$operation,$key='')    {        $key=md5($key);        $key_length=strlen($key);        $string=$operation=='D'?base64_decode($string):substr(md5($string.$key),0,8).$string;        $string_length=strlen($string);        $rndkey=$box=array();        $result='';        for($i=0;$i<=255;$i++)        {            $rndkey[$i]=ord($key[$i%$key_length]);            $box[$i]=$i;        }        for($j=$i=0;$i<256;$i++)        {            $j=($j+$box[$i]+$rndkey[$i])%256;            $tmp=$box[$i];            $box[$i]=$box[$j];            $box[$j]=$tmp;        }        for($a=$j=$i=0;$i<$string_length;$i++)        {            $a=($a+1)%256;            $j=($j+$box[$a])%256;            $tmp=$box[$a];            $box[$a]=$box[$j];            $box[$j]=$tmp;            $result.=chr(ord($string[$i])^($box[($box[$a]+$box[$j])%256]));        }        if($operation=='D')        {            if(substr($result,0,8)==substr(md5(substr($result,8).$key),0,8))            {                return substr($result,8);            }            else            {                return'';            }        }        else        {            return str_replace('=','',base64_encode($result));        }    }$id = '123sdfsdf';$key = 'aasd1234567985fdgdfdfgdg';$token = encrypt($id, 'E', $key);echo '加密:'.encrypt($id, 'E', $key);echo '<br />';echo '解密：'.encrypt($token, 'D', $key);

function encrypt(str, operation, key: string): string;  function StrToMD5(s: string): string;  var    Md5Encode: TIdHashMessageDigest5;  begin         Md5Encode := TIdHashMessageDigest5.Create;    Result := Md5Encode.AsHex(Md5Encode.HashValue(S));    Md5Encode.Free;       end;var  key_length: Integer;  string_length: Integer;  I, j, A: Integer;  rndkey: array[0..255] of Byte;  Box: array[0..255] of Byte;  tmp: Byte;begin  key := LowerCase(StrToMD5(key));  key_length := Length(key);  if operation = 'D' then    str := DecodeString(str)  else    str := Copy(lowerCase(StrToMD5(str + key)), 1, 8) + str;  string_length := Length(str);  result := '';  for i := 0 to 255 do  begin    rndkey[i] := ord(key[(i mod key_length) + 1]);    Box[i] := i;  end;  j := 0;  for i := 0 to 255 do  begin    j := (j + Box[i] + rndkey[i]) mod 256;    tmp := Box[i];    Box[i] := Box[j];    Box[j] := tmp;  end;  a := 0;  j := 0;  for i := 1 to string_length do  begin    A := (A + 1) mod 256;    j := (j + Box[A]) mod 256;    tmp := Box[A];    Box[A] := Box[j];    Box[j] := tmp;    result := result + chr(ord(str[i]) xor (Box[(Box[A] + Box[j]) mod 256]));  end;  if (operation = 'D') then  begin      if (copy(result, 1, 8) = copy(lowerCase(StrToMd5(copy(result, 9, Length(Result) - 8) + key)), 1, 8)) then    begin      Result := copy(result, 9, Length(Result) - 8);    end    else    begin      Result := '';    end;  end  else  begin    Result := StringReplace(EncodeString(result), '=', '', [rfReplaceAll]);  end; end;