DatabaseTool注册算法分析

DataBaseTool破解，
这个软件突破点在反汇编查找注册失败的地方
:00508775 DD1C24                  fstp qword ptr [esp]
:00508778 9B                      wait
:00508779 8D55F8                  lea edx, dword ptr [ebp-08]
:0050877C 8B83F8020000            mov eax, dword ptr [ebx+000002F8]
:00508782 E8110BF4FF              call 00449298
:00508787 8B55F8                  mov edx, dword ptr [ebp-08]
:0050878A 8BC3                    mov eax, ebx
:0050878C E8AFFDFFFF              call 00508540
:00508791 84C0                    test al, al
:00508793 742E                    je 005087C3
:00508795 C6057060520001          mov byte ptr [00526070], 01
:0050879C 8BC3                    mov eax, ebx
:0050879E E891FEFFFF              call 00508634

* Possible StringData Ref from Code Obj ->"注册成功!,请记下随机码.如果改变机器,请使用原来"
                                        ->"的随机码和注册码进行注册!"
                                  |
:005087A3 B8FC875000              mov eax, 005087FC
:005087A8 E8030F0000              call 005096B0
:005087AD A12C3E5200              mov eax, dword ptr [00523E2C]
:005087B2 8B00                    mov eax, dword ptr [eax]
:005087B4 8B80DC030000            mov eax, dword ptr [eax+000003DC]
:005087BA 33D2                    xor edx, edx
:005087BC E8F709F4FF              call 004491B8
:005087C1 EB0A                    jmp 005087CD

* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:00508793(C)
|

* Possible StringData Ref from Code Obj ->"注册失败!"
                                  |
:005087C3 B84C885000              mov eax, 0050884C
:005087C8 E8E30E0000              call 005096B0

可以看出:0050878C E8AFFDFFFF              call 00508540
这个call很关键，就在里面校验，
跟进去
005085DB   |.  8B45 F8        mov eax,dword ptr ss:[ebp-8]
005085DE   |.  8B55 F4        mov edx,dword ptr ss:[ebp-C]
005085E1   |.  E8 82C5EFFF    call unpacked.00404B68
005085E6   |.  75 02          jnz short unpacked.005085EA
005085E8   |.  B3 01          mov bl,1
005085EA   |>  33C0           xor eax,eax

在5085E1处看到注册码edx

"609968273"