ASCII "Registered User"
取ESI(源索引寄存器)存放的字符串长度送到EAX(累加器)
00403B43 |. 8B46 FC MOV EAX,DWORD PTR DS:[ESI-4]
EAX 00000006
ECX 77D1882A USER32.77D1882A
EDX 0000000F
EBX 00954954
ESP 0012F98C
EBP 0012F9B0
ESI 00953384 ASCII "Gemgin"
EDI 00441014 ASCII "Registered User"
EIP 00403B49 CrackMe3.00403B49
00403B49 |. 29D0
SUB EAX,EDX --EAX 减去EDX 结果保存到EAX 00000006-0000000F=FFFFFFF7
00403B50 |. C1EA 02
SHR EDX,2 6(H)=0110(B) 右移2位 0001(B)=00000001(H) 这里相当于EDX字符串长度除以4？