众所周知，目前很多共享软件现在都使用全局变量，作为软件注册与否的标志，在汇编中体现为在某个内存地址中，存入1或0，往往1代表已注册，0为共享状态，计算机专业用语中,这个内存地址称之为FLAG,当程序运行时，初始化值为0，读取windoz注册表或*.ini文件中的注册信息后，若已注册，那么flag值变为1，否则，继续保持为0，程序的其他部分可以访问这个flag,维持软件的共享状态。一般情况下，我们只是非常关注一些跳转，crack时有时很难见效！如果熟练掌握了注册Flag，在破解软件中有时会起到事半功倍的效果！下面我以一个教育教学软件为例，说明此法的应用。 有不当之处，垦请各位大虾指正！ 
        工具：Wdasm 8.93增强版：注[它可以直接查找汉字，对各种防止静态反编译的软件也可以反编译，如果没有的话，可以到：http://personal.dfminfo.com.cn/~kuangren处下载]                            Hacker view 很多版本都可以！ 
        对象：金数龙光学物理实验室 v1.01  可以到：http://luckteacher.yeah.net物理软件中下载！ 
        软件的保护：未注册时，程序启动时显示注册信息，共享时有功能限制，保存器件不能多于一个，程序未被压缩！程序运行时，在当前目录中产生s_data.obj文件，用来存放注册信息，注册成功后，注册信息就存放在此文件中，启动时，读此信息，显示在窗体上"属于xxx  xxx".如果删除此文件，启动后仍显示未注册！属共享状态！ 
        开始：执行仿真物理实验室.exe,跳出NAGS，要求注册等等，随意填写注册，对话框为"注册不成功"。关闭程序，检查一下，没加壳！太好了！（-_-）用Wdasm增强版反编译，查找"注册不成功"立即找到，注[可能显示为乱码，可启动Richwin或类似的软件即可看清汉字，但这毕竟不影响]代码如下：[共有两处] 
        :004370B1 8D45FC                  lea eax, dword ptr [ebp-04] 
:004370B4 E86342FDFF              call 0040B31C 
:004370B9 50                      push eax 
:004370BA 8D95A8F7FFFF            lea edx, dword ptr [ebp+FFFFF7A8] 
:004370C0 52                      push edx 
:004370C1 E8CEF10600              call 004A6294 
:004370C6 83C408                  add esp, 00000008 
:004370C9 33C9                    xor ecx, ecx 
:004370CB 894D8C                  mov dword ptr [ebp-74], ecx 
:004370CE 894D90                  mov dword ptr [ebp-70], ecx 
:004370D1 33C0                    xor eax, eax 
:004370D3 894588                  mov dword ptr [ebp-78], eax 

* Referenced by a (U)nconditional or (C)onditional Jump at Address: 
|:0043714E(C) 
| 
:004370D6 8B5588                  mov edx, dword ptr [ebp-78] 
:004370D9 80BC15A8F7FFFF00        cmp byte ptr [ebp+edx-00000858], 00 
:004370E1 90                      nop 
:004370E2 90                      nop 
:004370E3 8B4D88                  mov ecx, dword ptr [ebp-78] 
:004370E6 0FBE840DA8F7FFFF        movsx eax, byte ptr [ebp+ecx-00000858] 
:004370EE 8985A4F7FFFF            mov dword ptr [ebp+FFFFF7A4], eax 
:004370F4 DB85A4F7FFFF            fild dword ptr [ebp+FFFFF7A4] 
:004370FA 83C4F8                  add esp, FFFFFFF8 
:004370FD DD1C24                  fstp qword ptr [esp] 
:00437100 E88F3A0700              call 004AAB94 
:00437105 83C408                  add esp, 00000008 
:00437108 DB2D64744300            fld tbyte ptr [00437464] 
:0043710E DEC9                    fmulp st(1), st(0) 
:00437110 83C4F8                  add esp, FFFFFFF8 
:00437113 DD1C24                  fstp qword ptr [esp] 
:00437116 E895510700              call 004AC2B0 
:0043711B 83C408                  add esp, 00000008 
:0043711E D80D70744300            fmul dword ptr [00437470] 
:00437124 DC0574744300            fadd qword ptr [00437474] 
:0043712A 83C4F8                  add esp, FFFFFFF8 
:0043712D DD1C24                  fstp qword ptr [esp] 
:00437130 E82F380700              call 004AA964 
:00437135 83C408                  add esp, 00000008 
:00437138 D80D7C744300            fmul dword ptr [0043747C] 
:0043713E DC458C                  fadd qword ptr [ebp-74] 
:00437141 DD5D8C                  fstp qword ptr [ebp-74] 
:00437144 FF4588                  inc [ebp-78] 
:00437147 817D88D0070000          cmp dword ptr [ebp-78], 000007D0 
:0043714E 7C86                    jl 004370D6 
:00437150 66C745B45000            mov [ebp-4C], 0050 
:00437156 66C745B45C00            mov [ebp-4C], 005C 
:0043715C 8D45E0                  lea eax, dword ptr [ebp-20] 
:0043715F E844A7FCFF              call 004018A8 
:00437164 8BD0                    mov edx, eax 
:00437166 FF45C0                  inc [ebp-40] 
:00437169 8B4DA0                  mov ecx, dword ptr [ebp-60] 
:0043716C 8B81F0020000            mov eax, dword ptr [ecx+000002F0] 
:00437172 E885F70300              call 004768FC 
:00437177 8D45E0                  lea eax, dword ptr [ebp-20] 
:0043717A E885B60700              call 004B2804 
:0043717F DD5D94                  fstp qword ptr [ebp-6C] 
:00437182 FF4DC0                  dec [ebp-40] 
:00437185 8D45E0                  lea eax, dword ptr [ebp-20] 
:00437188 BA02000000              mov edx, 00000002 
:0043718D E8AAB40700              call 004B263C 
:00437192 66C745B41400            mov [ebp-4C], 0014 
:00437198 EB5F                    jmp 004371F9 
:0043719A 6A00                    push 00000000 

* Possible StringData Ref from Data Obj ->"提示" 
                                  | 
:0043719C B929234C00              mov ecx, 004C2329 

* Possible StringData Ref from Data Obj ->"注册不成功。" 
                                  | 
:004371A1 BA1C234C00              mov edx, 004C231C 
:004371A6 A18C714C00              mov eax, dword ptr [004C718C] 
:004371AB 8B00                    mov eax, dword ptr [eax] 
:004371AD E84EB30700              call 004B2500 
:004371B2 8B45A0                  mov eax, dword ptr [ebp-60] 
:004371B5 E86E1A0300              call 00468C28 
:004371BA FF4DC0                  dec [ebp-40] 
:004371BD 8D45F8                  lea eax, dword ptr [ebp-08] 
:004371C0 BA02000000              mov edx, 00000002 
:004371C5 E872B40700              call 004B263C 
:004371CA FF4DC0                  dec [ebp-40] 
:004371CD 8D45FC                  lea eax, dword ptr [ebp-04] 
:004371D0 BA02000000              mov edx, 00000002 
:004371D5 E862B40700              call 004B263C 
:004371DA 33C9                    xor ecx, ecx 
:004371DC 894DC0                  mov dword ptr [ebp-40], ecx 
:004371DF 8D45A4                  lea eax, dword ptr [ebp-5C] 
:004371E2 50                      push eax 
:004371E3 E8E78A0700              call 004AFCCF 
:004371E8 59                      pop ecx 
:004371E9 E96C020000              jmp 0043745A 
:004371EE 66C745B45800            mov [ebp-4C], 0058 
:004371F4 E82C840700              call 004AF625 

* Referenced by a (U)nconditional or (C)onditional Jump at Address: 
|:00437198(U)