极速IP搜索II

标题：发一篇C#.NET的破解文章，请各位指点指点:) (12千字)
作者：DarkNess0ut
时间：2002-12-18 1:47:10
链接：http://bbs.pediy.com

极速IP搜索II 破解文章:
软件制作平台:VS C#.NET
破解人:DarkNess0ut[FCG]
目的:了解VS.NET软件的破解,制作注册机
本文章只做研究使用!!

由于我答应了法语助手的作者,不再发布它的破解补丁文件:),所以本来要写VB.NET的文章改成了这个C#的文章,反正菩提兄写了详细的VB.NET的破解了:)

过程:
找到ILDASM.exe(好像在vs.net的第三张光盘吧),打开!
拖入SpeedII主程序,开始反汇编...OK
找到注册相关的地方(regB_Click 或启动监测处),打开!

拷贝的代码如下:
由于不做爆破,所以就不显示字节代码了,主要是算法分析(爆破也简单,一两个字节就行了)

.method private hidebysig instance void regB_Click(object sender,
class [mscorlib]System.EventArgs e) cil managed
{
// Code size 331 (0x14b)
.maxstack 5       //堆栈 5个
.locals init (char[] V_0,
char[] V_1,
int32 V_2,   0
int32 V_3,   1
int32 V_4,   2
string V_5,
int32 V_6,
bool V_7,
class [mscorlib]System.IO.StreamWriter V_8,
class [mscorlib]System.Exception V_9)
.try
{
IL_0000: ldc.i4.s 20   //压入 20
IL_0002: newarr [mscorlib]System.Char   //申明数组
IL_0007: stloc.0   //char[]=new str0[20]

IL_0008: ldc.i4.s 20   //压入 20
IL_000a: newarr [mscorlib]System.Char   //申明数组
IL_000f: stloc.1   //char[]=new str1[20]

IL_0010: ldarg.0       Arg0
IL_0011: ldfld class [System.Windows.Forms]System.Windows.Forms.TextBox SpeedIP_II.Reg::userName   //很明显,取用户名
IL_0016: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Control::get_Text()
IL_001b: callvirt instance char[] [mscorlib]System.String::ToCharArray()
IL_0020: stloc.0   //str0=username.tochararray(); 将用户名数组=>str0

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&//开始第一组计算
IL_0021: ldc.i4.0       //push 0 我按照字符解释为load (下同)
IL_0022: stloc.2   //set loc.2=0
IL_0023: br.s IL_0040 jump 40

IL_0025: ldloc.1       //load str1

IL_0026: ldloc.2       //load loc.2

>>>IL_0027: ldloc.0       //load str0
IL_0028: ldloc.2       //load loc.2
IL_0029: ldelem.u2       //[]
              //load str0[loc.2]
/IL_002a: ldloc.2       /load loc.2

|IL_002b: ldloc.0       // load str0
/ |IL_002c: ldlen       // len(str0)
| |IL_002d: conv.i4   =======//i4=len(str0)

| \IL_002e: add       //add

| /IL_002f: ldloc.0   =========// load loc.0
|IL_0030: ldlen       // len(loc.0)
| \IL_0031: conv.i4   =========//i4=len(loc.0)

\ IL_0032: mul       // *

IL_0033: add       // +

IL_0034: ldc.i4.s 26   // load 26
IL_0036: rem       // rem???这是什么

IL_0037: ldc.i4.s 65   // load 65
>>>IL_0039: add       // add

IL_003a: conv.u2       //???
IL_003b: stelem.i2       //[]

IL_003c: ldloc.2       //load loc.2
IL_003d: ldc.i4.1       //1
IL_003e: add       //I++
IL_003f: stloc.2       //set loc.2=

IL_0040: ldloc.2       //load loc.2

IL_0041: ldloc.0   //load loc.0
IL_0042: ldlen   //求长度
IL_0043: conv.i4       //i4=len(name)
IL_0044: blt.s IL_0025   //if loc.2<i4 then jump 0025
&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&
初看上面的代码觉得很乱,和菩提那篇介绍的不很一样,而且没有很多的提示,觉得很难理解
呵呵,后来我才发现了原因,解决的方法比较简单,
这个和那些写的很乱的代码很像,如果对上述代码做个下小小的变化
内容就显而易见了.

变化如下:
IL_0021: ldc.i4.0       //push 0 我按照字符ld解释为load (下同)
IL_0022: stloc.2   //set loc.2=0
IL_0023: br.s IL_0040 jump 40

IL_0025: ldloc.1       //load str1

IL_0026: ldloc.2       //load loc.2
{
{
{
IL_0027: ldloc.0       //load str0
IL_0028: ldloc.2       //load loc.2
IL_0029: ldelem.u2       //[]
              //load str0[loc.2] arg0
}
{
{
  IL_002a: ldloc.2       /load loc.2 arg1
  {
      IL_002b: ldloc.0       // load str0   //三行看作一个arg
      IL_002c: ldlen       // len(str0)
      IL_002d: conv.i4   =======//i4=len(str0) arg2
  }
  IL_002e: add       //add 运算
  //也就是arg1+arg2=>arg1+len(str0)===> arg3
}
{
  IL_002f: ldloc.0   =========// load loc.0
  IL_0030: ldlen       // len(loc.0)
  IL_0031: conv.i4   =========//i4=len(loc.0)
}
                  arg4=len(str0)
  IL_0032: mul       // * 运算 fsarg3*arg4=>arg5
}
IL_0033: add       // +
}
IL_0034: ldc.i4.s 26   // load 26
IL_0036: rem       // rem???这是什么这个就是取模运算啦
              //当初还以为是注释语句,哈哈,汇编代码也要注释?呵呵
IL_0037: ldc.i4.s 65   // load 65
  IL_0039: add       // add
}

IL_003a: conv.u2       //??? 哦这个就是将上述的结果conv一下
IL_003b: stelem.i2       //[] set elem i2?
结合上面的语句不难看出
//IL_0025: ldloc.1       //load str1
//IL_0026: ldloc.2       //load loc.2
//RESULT
//setelem.i2
//哦,str1[loc.2]=RESULT

IL_003c: ldloc.2       //load loc.2
IL_003d: ldc.i4.1       //1
IL_003e: add       //I++
IL_003f: stloc.2       //set loc.2=loc.2+1
//很明显,循环索引值嘛

IL_0040: ldloc.2       //load loc.2

IL_0041: ldloc.0   //load loc.0
IL_0042: ldlen   //求长度
IL_0043: conv.i4       //i4=len(name)
IL_0044: blt.s IL_0025   //if loc.2<i4 then jump 0025

分析,上述过程之所以看起来很复杂的原因是因为使用了套嵌,也就是编程使用了(),哈哈
所以上述的过程的算法为,VB表示
str0=name
for i=0 to len(str0)-1
  str1[lndex]=((str0[index]+(index+len(str0))*len(str0)) mod 26) +65
next
作用是将注册码限制到[A-Z]之间

看懂了这一段的话,下面的两段代码简直和看源代码一样啦
后面不作详细解释,我将各段用空行隔开了,只要记住
数据操作总是这样的形式
  push arg1
  push arg2
  operate
找到两个参数,和一个运算就行了,简单的很,
也就是所说的堆栈操作了,没有寄存器,看起来很别扭:)
就是套嵌看起来很复杂
要是可以做到和vs.net的代码操作一样,可以将代码收缩的话,哈哈!

***********************************************
IL_0046: ldloc.0
IL_0047: ldlen
IL_0048: conv.i4

IL_0049: stloc.3   //set loc.3=len(str0) //Index
IL_004a: br.s IL_0061   //Jump

IL_004c: ldloc.1   //str1[i]
IL_004d: ldloc.3

IL_004e: ldloc.0
IL_004f: ldc.i4.0
IL_0050: ldelem.u2

IL_0051: ldloc.3
IL_0052: mul

IL_0053: ldloc.3
IL_0054: mul

IL_0055: ldc.i4.s 26
IL_0057: rem

IL_0058: ldc.i4.s 65
IL_005a: add

IL_005b: conv.u2
IL_005c: stelem.i2

IL_005d: ldloc.3   //i
IL_005e: ldc.i4.1   //1
IL_005f: add   //i=i+1
IL_0060: stloc.3
IL_0061: ldloc.3           //round

IL_0062: ldc.i4.s 10   //?<10
IL_0064: blt.s IL_004c
***********************************************
上述运算
for Index=len(str0) to 10-1
  str1[Index]=(str0[0]*Index*Index mod 26) +65
next
============================================
IL_0066: ldc.i4.s 10
IL_0068: stloc.s V_4
IL_006a: br.s IL_0087
IL_006c: ldloc.1       //str1
IL_006d: ldloc.s V_4

IL_006f: ldloc.0

IL_0070: ldloc.0
IL_0071: ldlen
IL_0072: conv.i4

IL_0073: ldc.i4.1
IL_0074: sub

IL_0075: ldelem.u2

IL_0076: ldloc.s V_4
IL_0078: mul

IL_0079: ldc.i4.s 26
IL_007b: rem

IL_007c: ldc.i4.s 65
IL_007e: add

IL_007f: conv.u2
IL_0080: stelem.i2

IL_0081: ldloc.s V_4
IL_0083: ldc.i4.1
IL_0084: add
IL_0085: stloc.s V_4
IL_0087: ldloc.s V_4
IL_0089: ldc.i4.s 20
IL_008b: blt.s IL_006c
==============================================
For Index=10 to 20-1
  str1[Index]=(str0[len(str0)-1]*Index mod 26) +65
Next
到此,注册码的计算完成了,呵呵,还是较简单的吧
一共20位的注册码,这种算法是不行地:)
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IL_008d: ldstr "SpeedIPII-"
IL_0092: stloc.s V_5

IL_0094: ldc.i4.0
IL_0095: stloc.s V_6

IL_0097: br.s IL_00b5

IL_0099: ldloc.s V_5

IL_009b: ldloc.1
IL_009c: ldloc.s V_6
IL_009e: ldelema [mscorlib]System.Char
IL_00a3: call instance string [mscorlib]System.Char::ToString()
IL_00a8: call string [mscorlib]System.String::Concat(string,
string)
IL_00ad: stloc.s V_5 //最后将"SpeedIPII-" + 注册码=>完整的注册码

IL_00af: ldloc.s V_6
IL_00b1: ldc.i4.1
IL_00b2: add
IL_00b3: stloc.s V_6
IL_00b5: ldloc.s V_6
IL_00b7: ldc.i4.s 20
IL_00b9: blt.s IL_0099   //采用循环读取每个字节的方式
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@

IL_00bb: ldloc.s V_5
IL_00bd: ldarg.0
IL_00be: ldfld class [System.Windows.Forms]System.Windows.Forms.TextBox SpeedIP_II.Reg::userCode   //读取输入的注册码
IL_00c3: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Control::get_Text()
IL_00c8: callvirt instance bool [mscorlib]System.String::Equals(string)   //=?
IL_00cd: stloc.s V_7
IL_00cf: ldloc.s V_7
IL_00d1: brfalse.s IL_0122   // 如果不.则跳到122给你警告啦! 爆破也在这里啦
不过应该在启动的时候爆破,这里没有意义
IL_00d3: ldstr "ProgrameMessage.dll"
IL_00d8: call class [mscorlib]System.IO.StreamWriter [mscorlib]System.IO.File::CreateText(string)
IL_00dd: stloc.s V_8
IL_00df: ldloc.s V_8
IL_00e1: ldarg.0
IL_00e2: ldfld class [System.Windows.Forms]System.Windows.Forms.TextBox SpeedIP_II.Reg::userName
IL_00e7: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Control::get_Text()
IL_00ec: callvirt instance void [mscorlib]System.IO.TextWriter::WriteLine(string)
IL_00f1: ldloc.s V_8
IL_00f3: ldarg.0
IL_00f4: ldfld class [System.Windows.Forms]System.Windows.Forms.TextBox SpeedIP_II.Reg::userCode
IL_00f9: callvirt instance string [System.Windows.Forms]System.Windows.Forms.Control::get_Text()
IL_00fe: callvirt instance void [mscorlib]System.IO.TextWriter::WriteLine(string)
IL_0103: ldloc.s V_8
IL_0105: callvirt instance void [mscorlib]System.IO.TextWriter::Close()
IL_010a: ldstr bytearray (E8 6C 8C 51 10 62 9F 52 01 FF 1F 61 22 8C A8 60 // .l.Q.b.R...a"..`
84 76 E8 6C 8C 51 01 FF 08 FF F7 8B CD 91 B0 65 // .v.l.Q.........e
2F 54 A8 52 6F 8F F6 4E 09 FF ) // /T.Ro..N..
  //上面的这段数组,猜都能猜到是信息文字啦,那是什么呢,怎么看?
  //很简单阿,用一个Unicode=>ASCII的显示工具就可以看到了
  //正好做了一个小工具,显示看看
  //"注册成功！感谢您的注册！（请重新启动软件）"
  //哈哈,等的就是这个啦
IL_010f: ldstr bytearray (D0 63 3A 79 E1 4F 6F 60 ) // .c:y.Oo`
IL_0114: call valuetype [System.Windows.Forms]System.Windows.Forms.DialogResult [System.Windows.Forms]System.Windows.Forms.MessageBox::Show(string,
string)
IL_0119: pop
IL_011a: ldarg.0
IL_011b: call instance void [System.Windows.Forms]System.Windows.Forms.Form::Close()
IL_0120: br.s IL_0132
IL_0122: ldstr bytearray (F9 5B 0D 4E 77 8D 01 FF A8 60 40 62 93 8F 65 51 // .[.Nw....`@b..eQ
84 76 28 75 37 62 0D 54 8C 54 E8 6C 8C 51 01 78 // .v(u7b.T.T.l.Q.x
0D 4E 26 7B 01 FF ) // .N&{..
IL_0127: ldstr bytearray (D0 63 3A 79 E1 4F 6F 60 ) // .c:y.Oo`
IL_012c: call valuetype [System.Windows.Forms]System.Windows.Forms.DialogResult [System.Windows.Forms]System.Windows.Forms.MessageBox::Show(string,
string)
      //"对不起！您所输入的用户名和注册码不符！"
IL_0131: pop
IL_0132: leave.s IL_014a
} // end .try
catch [mscorlib]System.Exception
{
IL_0134: stloc.s V_9
IL_0136: ldloc.s V_9
IL_0138: callvirt instance string [mscorlib]System.Exception::get_Message()
IL_013d: ldstr bytearray (D0 63 3A 79 E1 4F 6F 60 ) // .c:y.Oo`
IL_0142: call valuetype [System.Windows.Forms]System.Windows.Forms.DialogResult [System.Windows.Forms]System.Windows.Forms.MessageBox::Show(string,
string)
IL_0147: pop
IL_0148: leave.s IL_014a
} // end handler
IL_014a: ret
} // end of method Reg::regB_Click

这是继法语助手Vb.net后我破解的第二个.net软件,
不过由于使用了一句语句的运算,使得结构看起来比较乱,还好搞定了!:)
哈哈,发文章了,好长时间没写了,手生了!

注册机的话,用VBs写就行了,反正简单,不写了!:)