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一个CrackMe的注册分析!!!(中级)

发表于: 2006-3-4 15:45 5285

一个CrackMe的注册分析!!!(中级)

jhlqb

2006-3-4 15:45

5285

这是前些天从这里下的一个Crackme,今天没事，看了看，也不知道是谁的了，也不知道有没有给出结果，就这样帖了，请作者谅解了！！！
OD载入，字符串查找，看看在下面下断点！
004014E5  |> /8D4D A0    /LEA ECX,DWORD PTR SS:[EBP-60] ;这是从下面上来的回调
004014E8  |. |E8 43ED0100 |CALL CrackMe3.00420230
004014ED  |. |8A45 EF    |MOV AL,BYTE PTR SS:[EBP-11]
004014F0  |. |6A 00       |PUSH 0                         ;  在这里下断点
004014F2  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
004014F5  |. |8845 CC    |MOV BYTE PTR SS:[EBP-34],AL
004014F8  |. |E8 A3050000 |CALL CrackMe3.00401AA0
004014FD  |. |8A4D EF    |MOV CL,BYTE PTR SS:[EBP-11]
00401500  |. |6A 00       |PUSH 0
00401502  |. |884D DC    |MOV BYTE PTR SS:[EBP-24],CL
00401505  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
00401508  |. |C645 FC 18 |MOV BYTE PTR SS:[EBP-4],18
0040150C  |. |E8 8F050000 |CALL CrackMe3.00401AA0
00401511  |. |8D4D A0    |LEA ECX,DWORD PTR SS:[EBP-60]
00401514  |. |C645 FC 19 |MOV BYTE PTR SS:[EBP-4],19
00401518  |. |E8 237B0100 |CALL CrackMe3.00419040
0040151D  |. |85C0       |TEST EAX,EAX
0040151F  |. |0F85 5B030000 |JNZ CrackMe3.00401880
00401525  |. |8B5D C4    |MOV EBX,DWORD PTR SS:[EBP-3C]
00401528  |. |8BCB       |MOV ECX,EBX
0040152A  |. |E8 51710200 |CALL CrackMe3.00428680
0040152F  |. |8378 08 02 |CMP DWORD PTR DS:[EAX+8],2    ;  注册码的长度要大于2
00401533  |. |0F87 A6000000 |JA CrackMe3.004015DF
00401539  |. |8B4D C8    |MOV ECX,DWORD PTR SS:[EBP-38]
0040153C  |. |E8 3F710200 |CALL CrackMe3.00428680
00401541  |. |8B70 08    |MOV ESI,DWORD PTR DS:[EAX+8]
00401544  |. |8BCB       |MOV ECX,EBX
00401546  |. |E8 35710200 |CALL CrackMe3.00428680
0040154B  |. |3B70 08    |CMP ESI,DWORD PTR DS:[EAX+8]
0040154E  |. |0F87 8B000000 |JA CrackMe3.004015DF
00401554  |. |BF B0464D00 |MOV EDI,CrackMe3.004D46B0    ;  ASCII "Sorry"
00401559  |. |83C9 FF    |OR ECX,FFFFFFFF
0040155C  |. |33C0       |XOR EAX,EAX
0040155E  |. |6A 01       |PUSH 1
00401560  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
00401562  |. |F7D1       |NOT ECX
00401564  |. |49          |DEC ECX
00401565  |. |8BD9       |MOV EBX,ECX
00401567  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
0040156A  |. |53          |PUSH EBX
0040156B  |. |E8 F0050000 |CALL CrackMe3.00401B60
00401570  |. |84C0       |TEST AL,AL
00401572  |. |74 21       |JE SHORT CrackMe3.00401595
00401574  |. |8B7D D0    |MOV EDI,DWORD PTR SS:[EBP-30]
00401577  |. |8BCB       |MOV ECX,EBX
00401579  |. |8BD1       |MOV EDX,ECX
0040157B  |. |BE B0464D00 |MOV ESI,CrackMe3.004D46B0    ;  ASCII "Sorry"
00401580  |. |C1E9 02    |SHR ECX,2
00401583  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
00401585  |. |8BCA       |MOV ECX,EDX
00401587  |. |53          |PUSH EBX
00401588  |. |83E1 03    |AND ECX,3
0040158B  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
0040158D  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
00401590  |. |E8 AB050000 |CALL CrackMe3.00401B40
00401595  |> |BF 9C464D00 |MOV EDI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
0040159A  |. |83C9 FF    |OR ECX,FFFFFFFF
0040159D  |. |33C0       |XOR EAX,EAX
0040159F  |. |6A 01       |PUSH 1
004015A1  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
004015A3  |. |F7D1       |NOT ECX
004015A5  |. |49          |DEC ECX
004015A6  |. |8BD9       |MOV EBX,ECX
004015A8  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
004015AB  |. |53          |PUSH EBX
004015AC  |. |E8 AF050000 |CALL CrackMe3.00401B60
004015B1  |. |84C0       |TEST AL,AL
004015B3  |. |0F84 B1020000 |JE CrackMe3.0040186A
004015B9  |. |8B7D E0    |MOV EDI,DWORD PTR SS:[EBP-20]
004015BC  |. |8BCB       |MOV ECX,EBX
004015BE  |. |8BC1       |MOV EAX,ECX
004015C0  |. |BE 9C464D00 |MOV ESI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
004015C5  |. |C1E9 02    |SHR ECX,2
004015C8  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
004015CA  |. |8BC8       |MOV ECX,EAX
004015CC  |. |53          |PUSH EBX
004015CD  |. |83E1 03    |AND ECX,3
004015D0  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
004015D2  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
004015D5  |. |E8 66050000 |CALL CrackMe3.00401B40
004015DA  |. |E9 8B020000 |JMP CrackMe3.0040186A
004015DF  |> |8B7D C8    |MOV EDI,DWORD PTR SS:[EBP-38]
004015E2  |. |33F6       |XOR ESI,ESI
004015E4  |> |8BCF       |/MOV ECX,EDI                   ;  下面的函数过程是判断用户名

是否全是字符
004015E6  |. |E8 95700200 ||CALL CrackMe3.00428680
004015EB  |. |3B70 08    ||CMP ESI,DWORD PTR DS:[EAX+8] ;  用户名的位数在[EAX+8]中，

是否为0
004015EE  |. |73 53       ||JNB SHORT CrackMe3.00401643 ;  在这里跳出循环
004015F0  |. |8BCF       ||MOV ECX,EDI
004015F2  |. |E8 89700200 ||CALL CrackMe3.00428680
004015F7  |. |8B40 04    ||MOV EAX,DWORD PTR DS:[EAX+4] ;  去取用户名的地址
004015FA  |. |85C0       ||TEST EAX,EAX
004015FC  |. |75 07       ||JNZ SHORT CrackMe3.00401605
004015FE  |. |B8 C8A74B00 ||MOV EAX,CrackMe3.004BA7C8
00401603  |. |EB 02       ||JMP SHORT CrackMe3.00401607
00401605  |> |03C6       ||ADD EAX,ESI                   ;  向后移动指针
00401607  |> |0FBE08       ||MOVSX ECX,BYTE PTR DS:[EAX] ;  取用户名的第一位
0040160A  |. |51          ||PUSH ECX
0040160B  |. |E8 99130900 ||CALL CrackMe3.004929A9       ;  判定第一位是否是大写字符
00401610  |. |83C4 04    ||ADD ESP,4
00401613  |. |83F8 61    ||CMP EAX,61                   ;  与字符"a"的ASCII码比较
00401616  |. |7C 2B       ||JL SHORT CrackMe3.00401643
00401618  |. |8BCF       ||MOV ECX,EDI
0040161A  |. |E8 61700200 ||CALL CrackMe3.00428680
0040161F  |. |8B40 04    ||MOV EAX,DWORD PTR DS:[EAX+4]
00401622  |. |85C0       ||TEST EAX,EAX
00401624  |. |75 07       ||JNZ SHORT CrackMe3.0040162D
00401626  |. |B8 C8A74B00 ||MOV EAX,CrackMe3.004BA7C8
0040162B  |. |EB 02       ||JMP SHORT CrackMe3.0040162F
0040162D  |> |03C6       ||ADD EAX,ESI
0040162F  |> |0FBE10       ||MOVSX EDX,BYTE PTR DS:[EAX]
00401632  |. |52          ||PUSH EDX
00401633  |. |E8 71130900 ||CALL CrackMe3.004929A9
00401638  |. |83C4 04    ||ADD ESP,4
0040163B  |. |83F8 7A    ||CMP EAX,7A                   ;  与字符"z"的ASCII码比较
0040163E  |. |7F 03       ||JG SHORT CrackMe3.00401643
00401640  |. |46          ||INC ESI
00401641  |.^|EB A1       |\JMP SHORT CrackMe3.004015E4
00401643  |> |8BCF       |MOV ECX,EDI
00401645  |. |E8 36700200 |CALL CrackMe3.00428680
0040164A  |. |3B70 08    |CMP ESI,DWORD PTR DS:[EAX+8]
0040164D  |. |0F83 8B000000 |JNB CrackMe3.004016DE
00401653  |> |33C0       |XOR EAX,EAX
00401655  |. |BF B0464D00 |MOV EDI,CrackMe3.004D46B0    ;  ASCII "Sorry"
0040165A  |. |83C9 FF    |OR ECX,FFFFFFFF
0040165D  |. |6A 01       |PUSH 1
0040165F  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
00401661  |. |F7D1       |NOT ECX
00401663  |. |49          |DEC ECX
00401664  |. |8BD9       |MOV EBX,ECX
00401666  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
00401669  |. |53          |PUSH EBX
0040166A  |. |E8 F1040000 |CALL CrackMe3.00401B60
0040166F  |. |84C0       |TEST AL,AL
00401671  |. |74 21       |JE SHORT CrackMe3.00401694
00401673  |. |8B7D D0    |MOV EDI,DWORD PTR SS:[EBP-30]
00401676  |. |8BCB       |MOV ECX,EBX
00401678  |. |8BC1       |MOV EAX,ECX
0040167A  |. |BE B0464D00 |MOV ESI,CrackMe3.004D46B0    ;  ASCII "Sorry"
0040167F  |. |C1E9 02    |SHR ECX,2
00401682  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
00401684  |. |8BC8       |MOV ECX,EAX
00401686  |. |53          |PUSH EBX
00401687  |. |83E1 03    |AND ECX,3
0040168A  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
0040168C  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
0040168F  |. |E8 AC040000 |CALL CrackMe3.00401B40
00401694  |> |BF 9C464D00 |MOV EDI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
00401699  |. |83C9 FF    |OR ECX,FFFFFFFF
0040169C  |. |33C0       |XOR EAX,EAX
0040169E  |. |6A 01       |PUSH 1
004016A0  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
004016A2  |. |F7D1       |NOT ECX
004016A4  |. |49          |DEC ECX
004016A5  |. |8BD9       |MOV EBX,ECX
004016A7  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
004016AA  |. |53          |PUSH EBX
004016AB  |. |E8 B0040000 |CALL CrackMe3.00401B60
004016B0  |. |84C0       |TEST AL,AL
004016B2  |. |0F84 B2010000 |JE CrackMe3.0040186A
004016B8  |. |8B7D E0    |MOV EDI,DWORD PTR SS:[EBP-20]
004016BB  |. |8BCB       |MOV ECX,EBX
004016BD  |. |8BD1       |MOV EDX,ECX
004016BF  |. |BE 9C464D00 |MOV ESI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
004016C4  |. |C1E9 02    |SHR ECX,2
004016C7  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
004016C9  |. |8BCA       |MOV ECX,EDX
004016CB  |. |53          |PUSH EBX
004016CC  |. |83E1 03    |AND ECX,3
004016CF  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
004016D1  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
004016D4  |. |E8 67040000 |CALL CrackMe3.00401B40
004016D9  |. |E9 8C010000 |JMP CrackMe3.0040186A
004016DE  |> |8BCB       |MOV ECX,EBX
004016E0  |. |E8 9B6F0200 |CALL CrackMe3.00428680       ;  取注册码的地址
004016E5  |. |8B40 04    |MOV EAX,DWORD PTR DS:[EAX+4]
004016E8  |. |85C0       |TEST EAX,EAX
004016EA  |. |75 05       |JNZ SHORT CrackMe3.004016F1
004016EC  |. |B8 C8A74B00 |MOV EAX,CrackMe3.004BA7C8
004016F1  |> |50          |PUSH EAX
004016F2  |. |E8 A7120900 |CALL CrackMe3.0049299E       ;  这个函数将注册码的ASCII码

的字符串转换成数值
004016F7  |. |50          |PUSH EAX                      ;  eax中为输入的注册码的数值
004016F8  |. |E8 03F9FFFF |CALL CrackMe3.00401000       ;  关键函数；函数代码在后面
004016FD  |. |83C4 08    |ADD ESP,8
00401700  |. |84C0       |TEST AL,AL
00401702  |.^|0F84 4BFFFFFF |JE CrackMe3.00401653          ;  回跳，退出
00401708  |. |8BCB       |MOV ECX,EBX
0040170A  |. |E8 716F0200 |CALL CrackMe3.00428680
0040170F  |. |8B40 08    |MOV EAX,DWORD PTR DS:[EAX+8] ;  注册码的位数
00401712  |. |33DB       |XOR EBX,EBX
00401714  |. |8D78 FF    |LEA EDI,DWORD PTR DS:[EAX-1]
00401717  |> |3BDF       |/CMP EBX,EDI                   ;  下面的循环实现了判断是否注

册码为对称值的判断，不是就退出
00401719  |. |0F8F C7000000 ||JG CrackMe3.004017E6          ;  跳，就注册成功
0040171F  |. |8B4D C4    ||MOV ECX,DWORD PTR SS:[EBP-3C]
00401722  |. |E8 596F0200 ||CALL CrackMe3.00428680
00401727  |. |8B40 04    ||MOV EAX,DWORD PTR DS:[EAX+4]
0040172A  |. |BE C8A74B00 ||MOV ESI,CrackMe3.004BA7C8
0040172F  |. |85C0       ||TEST EAX,EAX
00401731  |. |74 03       ||JE SHORT CrackMe3.00401736
00401733  |. |8D3418       ||LEA ESI,DWORD PTR DS:[EAX+EBX]
00401736  |> |8B4D C4    ||MOV ECX,DWORD PTR SS:[EBP-3C]
00401739  |. |E8 426F0200 ||CALL CrackMe3.00428680
0040173E  |. |8B40 04    ||MOV EAX,DWORD PTR DS:[EAX+4]
00401741  |. |85C0       ||TEST EAX,EAX
00401743  |. |75 07       ||JNZ SHORT CrackMe3.0040174C
00401745  |. |B8 C8A74B00 ||MOV EAX,CrackMe3.004BA7C8
0040174A  |. |EB 02       ||JMP SHORT CrackMe3.0040174E
0040174C  |> |03C7       ||ADD EAX,EDI
0040174E  |> |8A0E       ||MOV CL,BYTE PTR DS:[ESI]
00401750  |. |8A10       ||MOV DL,BYTE PTR DS:[EAX]
00401752  |. |3ACA       ||CMP CL,DL                   ;  第一位和最后一位是否相等
00401754  |. |75 04       ||JNZ SHORT CrackMe3.0040175A ;  跳，就OVER
00401756  |. |4F          ||DEC EDI
00401757  |. |43          ||INC EBX
00401758  |.^|EB BD       |\JMP SHORT CrackMe3.00401717
0040175A  |> |BF B0464D00 |MOV EDI,CrackMe3.004D46B0    ;  ASCII "Sorry"
0040175F  |. |83C9 FF    |OR ECX,FFFFFFFF
00401762  |. |33C0       |XOR EAX,EAX
00401764  |. |6A 01       |PUSH 1
00401766  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
00401768  |. |F7D1       |NOT ECX
0040176A  |. |49          |DEC ECX
0040176B  |. |8BD9       |MOV EBX,ECX
0040176D  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
00401770  |. |53          |PUSH EBX
00401771  |. |E8 EA030000 |CALL CrackMe3.00401B60
00401776  |. |84C0       |TEST AL,AL
00401778  |. |74 21       |JE SHORT CrackMe3.0040179B
0040177A  |. |8B7D D0    |MOV EDI,DWORD PTR SS:[EBP-30]
0040177D  |. |8BCB       |MOV ECX,EBX
0040177F  |. |8BD1       |MOV EDX,ECX
00401781  |. |BE B0464D00 |MOV ESI,CrackMe3.004D46B0    ;  ASCII "Sorry"
00401786  |. |C1E9 02    |SHR ECX,2
00401789  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
0040178B  |. |8BCA       |MOV ECX,EDX
0040178D  |. |53          |PUSH EBX
0040178E  |. |83E1 03    |AND ECX,3
00401791  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
00401793  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
00401796  |. |E8 A5030000 |CALL CrackMe3.00401B40
0040179B  |> |BF 9C464D00 |MOV EDI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
004017A0  |. |83C9 FF    |OR ECX,FFFFFFFF
004017A3  |. |33C0       |XOR EAX,EAX
004017A5  |. |6A 01       |PUSH 1
004017A7  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
004017A9  |. |F7D1       |NOT ECX
004017AB  |. |49          |DEC ECX
004017AC  |. |8BD9       |MOV EBX,ECX
004017AE  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
004017B1  |. |53          |PUSH EBX
004017B2  |. |E8 A9030000 |CALL CrackMe3.00401B60
004017B7  |. |84C0       |TEST AL,AL
004017B9  |. |0F84 AB000000 |JE CrackMe3.0040186A
004017BF  |. |8B7D E0    |MOV EDI,DWORD PTR SS:[EBP-20]
004017C2  |. |8BCB       |MOV ECX,EBX
004017C4  |. |8BC1       |MOV EAX,ECX
004017C6  |. |BE 9C464D00 |MOV ESI,CrackMe3.004D469C    ;  ASCII "Register Failed!"
004017CB  |. |C1E9 02    |SHR ECX,2
004017CE  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
004017D0  |. |8BC8       |MOV ECX,EAX
004017D2  |. |83E1 03    |AND ECX,3
004017D5  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
004017D7  |. |8B4D E0    |MOV ECX,DWORD PTR SS:[EBP-20]
004017DA  |. |895D E4    |MOV DWORD PTR SS:[EBP-1C],EBX
004017DD  |. |C60419 00    |MOV BYTE PTR DS:[ECX+EBX],0
004017E1  |. |E9 84000000 |JMP CrackMe3.0040186A
004017E6  |> |BF 8C464D00 |MOV EDI,CrackMe3.004D468C    ;  ASCII "Congratulate"
004017EB  |. |83C9 FF    |OR ECX,FFFFFFFF
004017EE  |. |33C0       |XOR EAX,EAX
004017F0  |. |6A 01       |PUSH 1
004017F2  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI] ;  扫描字符"C",得到字符串

Congratulate的长度
004017F4  |. |F7D1       |NOT ECX
004017F6  |. |49          |DEC ECX
004017F7  |. |8BD9       |MOV EBX,ECX
004017F9  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
004017FC  |. |53          |PUSH EBX
004017FD  |. |E8 5E030000 |CALL CrackMe3.00401B60
00401802  |. |84C0       |TEST AL,AL
00401804  |. |74 22       |JE SHORT CrackMe3.00401828    ;  跳，就成功
00401806  |. |8B7D D0    |MOV EDI,DWORD PTR SS:[EBP-30]
00401809  |. |8BCB       |MOV ECX,EBX
0040180B  |. |8BD1       |MOV EDX,ECX
0040180D  |. |BE 8C464D00 |MOV ESI,CrackMe3.004D468C    ;  ASCII "Congratulate"
00401812  |. |C1E9 02    |SHR ECX,2
00401815  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
00401817  |. |8BCA       |MOV ECX,EDX
00401819  |. |83E1 03    |AND ECX,3
0040181C  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
0040181E  |. |8B45 D0    |MOV EAX,DWORD PTR SS:[EBP-30]
00401821  |. |895D D4    |MOV DWORD PTR SS:[EBP-2C],EBX
00401824  |. |C60418 00    |MOV BYTE PTR DS:[EAX+EBX],0
00401828  |> |BF 78464D00 |MOV EDI,CrackMe3.004D4678    ;  ASCII "Register Succeed!"
0040182D  |. |83C9 FF    |OR ECX,FFFFFFFF
00401830  |. |33C0       |XOR EAX,EAX
00401832  |. |6A 01       |PUSH 1
00401834  |. |F2:AE       |REPNE SCAS BYTE PTR ES:[EDI]
00401836  |. |F7D1       |NOT ECX
00401838  |. |49          |DEC ECX
00401839  |. |8BD9       |MOV EBX,ECX
0040183B  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
0040183E  |. |53          |PUSH EBX
0040183F  |. |E8 1C030000 |CALL CrackMe3.00401B60
00401844  |. |84C0       |TEST AL,AL
00401846  |. |74 22       |JE SHORT CrackMe3.0040186A
00401848  |. |8B7D E0    |MOV EDI,DWORD PTR SS:[EBP-20]
0040184B  |. |8BCB       |MOV ECX,EBX
0040184D  |. |8BD1       |MOV EDX,ECX
0040184F  |. |BE 78464D00 |MOV ESI,CrackMe3.004D4678    ;  ASCII "Register Succeed!"
00401854  |. |C1E9 02    |SHR ECX,2
00401857  |. |F3:A5       |REP MOVS DWORD PTR ES:[EDI],DWO>
00401859  |. |8BCA       |MOV ECX,EDX
0040185B  |. |83E1 03    |AND ECX,3
0040185E  |. |F3:A4       |REP MOVS BYTE PTR ES:[EDI],BYTE>
00401860  |. |8B45 E0    |MOV EAX,DWORD PTR SS:[EBP-20]
00401863  |. |895D E4    |MOV DWORD PTR SS:[EBP-1C],EBX
00401866  |. |C60418 00    |MOV BYTE PTR DS:[EAX+EBX],0
0040186A  |> |8D4D 94    |LEA ECX,DWORD PTR SS:[EBP-6C]
0040186D  |. |6A 00       |PUSH 0
0040186F  |. |8D55 DC    |LEA EDX,DWORD PTR SS:[EBP-24]
00401872  |. |51          |PUSH ECX
00401873  |. |8D45 CC    |LEA EAX,DWORD PTR SS:[EBP-34]
00401876  |. |52          |PUSH EDX
00401877  |. |50          |PUSH EAX
00401878  |. |E8 C3CE0100 |CALL CrackMe3.0041E740
0040187D  |. |83C4 10    |ADD ESP,10
00401880  |> |6A 01       |PUSH 1
00401882  |. |8D4D DC    |LEA ECX,DWORD PTR SS:[EBP-24]
00401885  |. |C645 FC 18 |MOV BYTE PTR SS:[EBP-4],18
00401889  |. |E8 12020000 |CALL CrackMe3.00401AA0
0040188E  |. |6A 01       |PUSH 1
00401890  |. |8D4D CC    |LEA ECX,DWORD PTR SS:[EBP-34]
00401893  |. |C645 FC 10 |MOV BYTE PTR SS:[EBP-4],10
00401897  |. |E8 04020000 |CALL CrackMe3.00401AA0
0040189C  |. |8D4D A0    |LEA ECX,DWORD PTR SS:[EBP-60]
0040189F  |. |E8 9C770100 |CALL CrackMe3.00419040
004018A4  |. |83F8 01    |CMP EAX,1
004018A7  |.^\0F85 38FCFFFF \JNZ CrackMe3.004014E5
004018AD  |.  E8 FE4C0800 CALL CrackMe3.004865B0

这是关键函数的代码：

00401000  /$  56          PUSH ESI
00401001  |.  8B7424 08    MOV ESI,DWORD PTR SS:[ESP+8]
00401005  |.  83FE 02    CMP ESI,2                      ;  注册码为2就退出
00401008  |.  75 04       JNZ SHORT CrackMe3.0040100E
0040100A  |.  B0 01       MOV AL,1
0040100C  |.  5E          POP ESI
0040100D  |.  C3          RETN
0040100E  |>  85F6       TEST ESI,ESI
00401010  |.  74 42       JE SHORT CrackMe3.00401054
00401012  |.  83FE 01    CMP ESI,1
00401015  |.  74 3D       JE SHORT CrackMe3.00401054    ;  跳就OVER
00401017  |.  8BC6       MOV EAX,ESI
00401019  |.  25 01000080 AND EAX,80000001                ;  最高位和最低位是否为1,其余

位清零
0040101E  |.  79 05       JNS SHORT CrackMe3.00401025
00401020  |.  48          DEC EAX
00401021  |.  83C8 FE    OR EAX,FFFFFFFE
00401024  |.  40          INC EAX
00401025  |>  74 2D       JE SHORT CrackMe3.00401054    ;  跳就OVER
00401027  |.  DB4424 08    FILD DWORD PTR SS:[ESP+8]
0040102B  |.  D9FA       FSQRT                         ;  对注册码的数值进行开方
0040102D  |.  E8 B6170900 CALL CrackMe3.004927E8          ;  取整注册码的开方值
00401032  |.  8BC8       MOV ECX,EAX
00401034  |.  83F9 03    CMP ECX,3
00401037  |.  7C 11       JL SHORT CrackMe3.0040104A    ;  小于3，就退出
00401039  |>  8BC6       /MOV EAX,ESI                   ;  若注册码为s,则这里计算s/

([sqr(s)]-2)的余数，余数为0或者([sqr(s)]-2)<=3退出循环
0040103B  |.  99          |CDQ
0040103C  |.  F7F9       |IDIV ECX
0040103E  |.  85D2       |TEST EDX,EDX
00401040  |.  74 08       |JE SHORT CrackMe3.0040104A
00401042  |.  83E9 02    |SUB ECX,2
00401045  |.  83F9 03    |CMP ECX,3
00401048  |.^ 7D EF       \JGE SHORT CrackMe3.00401039
0040104A  |>  33C0       XOR EAX,EAX
0040104C  |.  83F9 03    CMP ECX,3
0040104F  |.  0F9CC0       SETL AL                         ; 标志位sf与of值异或的结果
00401052  |.  5E          POP ESI
00401053  |.  C3          RETN
00401054  |>  32C0       XOR AL,AL
00401056  |.  5E          POP ESI
00401057  \.  C3          RETN

分析总结：
（1）要求注册的用户名必须是字母，并且不能是零长
（2）注册码有以下限制：
   ①必须是整数
   ②回文（即第一位和最后位相同，第二位与倒数第二位相同，依次类推）
   ③从注册码的开方值取整后开始以步长为2来寻找第一个能被注册码整除的数，并且这个数要小

   于等于3，也就是说这个数应该为质数
   综合以上分析，这里的注册码应该是质数中的回文.
注册函数VC++编译通过如下：
#include "stdafx.h"
#include "iostream.h"
void main()
{int i;

for(i=10;i<500;i++)
{
   if (((i<100) &&((i/10)==(i%10)) && (i%2!=0))||(((i>100) && (i/100)==(i%10) && (i%

2)!=0)))

cout<<"The Number "<<i<<" is one of the Code!"<<endl;

  }
}

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斩天雪币： 225 活跃值： (1236) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 115 粉丝 0 关注私信	斩天 2 楼顶一个不过 Crackme 下载后解压失败 2006-3-5 08:56 0
angie 雪币： 200 活跃值： (42) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 67 粉丝 1 关注私信	angie 3 楼顶,学习一下! 2006-3-5 11:32 0
晴空雪币： 200 活跃值： (10) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 41 粉丝 0 关注私信	晴空 4 楼这个CrackMe在什么地方还能找到吗？上面那个文件已经损坏了。 2006-3-5 14:48 0
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最新回复 (4)
斩天雪币： 225 活跃值： (1236) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 115 粉丝 0 关注私信	斩天 2 楼顶一个不过 Crackme 下载后解压失败 2006-3-5 08:56 0
angie 雪币： 200 活跃值： (42) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 67 粉丝 1 关注私信	angie 3 楼顶,学习一下! 2006-3-5 11:32 0
晴空雪币： 200 活跃值： (10) 能力值： ( LV2，RANK：10 ) 在线值：发帖 4 回帖 41 粉丝 0 关注私信	晴空 4 楼这个CrackMe在什么地方还能找到吗？上面那个文件已经损坏了。 2006-3-5 14:48 0
jhlqb 雪币： 289 活跃值： (236) 能力值： ( LV13，RANK：420 ) 在线值：发帖 24 回帖 94 粉丝 0 关注私信	jhlqb 10 5 楼对不起,前几天下的,一直到周末才有时间整理,不知道上传出错了!!! 也不知道是谁的!!!我修改一下了!!! 2006-3-5 15:15 0
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