传奇3封包加密解密

最新推荐文章于 2023-03-27 17:29:23 发布

转载最新推荐文章于 2023-03-27 17:29:23 发布 · 5.2k 阅读

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传奇3封包加密解密程序下载

这种软件的核心就两个函数,一个加密一个解密,这两个函数在做封包分析的过程中起很重要的作用:

Function Decode(source: string): string;
Var
  Source_Len,Len : integer;
  Count,c1,c2 : integer;
  code : array[0..7] of byte;
  a1,a2 : byte;
  ind : dword;
  Decode_Str : string;
  label L1,L2;
Begin
  Result := '';
  Decode_Str := '';
  code[2] := $fc;
  code[4] := $f0;
  code[6] := $c0;
  Len := 0;
  a1 := 0;
  a2 := 0;
  c1 := 2;
  c2 := 0;
  ind := 0;
  Count := 0;
  Source_Len := Length(source);
  while (Count < Source_Len) do
    begin
      if(ord(Source[Count+1]) - $3c) < 0 then
        begin
          Decode_Str := Decode_Str + Source[Count+1];
          inc(Len);
          inc(Count);
          a1 := 0;
          a2 := 0;
          c1 := 2;
          c2 := 0;
          ind := 0;
          Continue;
          //break;
        end;
      a1 := ord(Source[Count+1]) - $3c;
      if Len >= Source_Len then
        begin
          break;
        end;
      if (c2 + 6) < 8 then
        begin
          goto L2;
        end;
      ind := a1 and $3f;
      ind := ind shr (6-c1);
      Decode_Str := Decode_Str + chr(ind or a2);
      Inc(Len);
      c2 := 0;
      if c1 >= 6 then
        begin
          c1 := 2;
          goto L1;
        end;
      inc(c1,2);
      L2 :a2 := a1 shl c1;
      a2 := a2 and code[c1];
      c2 := c2 + (8 - c1);
      L1 :inc(count);
    end;
    SetLength(Decode_Str,Len);
    Result := Decode_Str;
end;

function Encode(source: string): string;
var
  Source_Len,Len : integer;
  Count,c : integer;
  a1,a2 : byte;
  ind : dword;
  Encode_Str : string;
begin
Result := '';
Encode_Str := '';
Len := 0;
a1 := 0;
a2 := 0;
c := 0;
ind := 0;
Count := 0;
Source_Len := Length(source);
while Count < Source_Len do
begin
if Len >= $2710 then
break;
ind := ord(source[Count+1]);
ind := ind shr (c+2);
a1 := ind or a2;
a1 := a1 and $3f;
ind := ord(source[Count+1]);
ind := ind shl (8-(c+2));
ind := ind shr 2;
a2 := ind and $3f;
inc(c,2);
if c >= 6 then
begin
if Len >= $270f then
begin
Encode_Str := Encode_Str + chr(a1 + $3c);
inc(Len);
end
else
begin
Encode_Str := Encode_Str + chr(a1 + $3c);
Encode_Str := Encode_Str + chr(a2 + $3c);
Inc(Len,2);
end;
c := 0;
a2 := 0;
end
else
begin
Encode_Str := Encode_Str + chr(a1 + $3c);
Inc(Len);
end;
inc(Count);
end;
if c > 0 then
begin
Encode_Str := Encode_Str + chr(a2 + $3c);
Inc(Len);
end;
SetLength(Encode_Str,Len);
Result := Encode_Str;
end;