作业

汇编

1. 该函数是将CCCC赋值于ax 并将值后赋值于bx中的地址，并依次写入128次，每次写入便将bx所代表的地址累加。

   改写 ：

   func_1:
       mov ax, CCCC
       mov cx, 128
       mov dx,0
   MyLoop: 
       mov [bx], ax
       add bx, 2
       add dx, 1
       cmp dx,cx
       jnz MyLoop
       ret
   

2. 分析后可知该代码获取了str的长度 并读取，后异或33h后将值赋给str 所以加密方式为 str[i]^33h

a = [0x5b,0x54,0x52,0x5e,0x56,0x48,0x44,0x56,0x5f,0x50,0x3,0x5e,0x56,0x6c,0x47,0x3,0x6c,0x41,0x56,0x6c,0x44,0x5c,0x41,0x2,0x57,0x12,0x4e]
flag = ""
for i in range(len(a)):
    flag+=chr(a[i]^0x33)
print(flag)

flag = hgame{welc0me_t0_re_wor1d!}

python

def Factorial(num):
    if num == 1:
        return 1
    else :
        return Factorial(num-1)*num
a = int (input())
print(Factorial(a))

a=[]
it=[x for x in input().split(',')]
for i in it:
    x = int (i,2)
    if x%5==0:
        a.append(i)
print(','.join(a))

RE

用ida打开附件后 可知

flag{this_Is_a_EaSyRe}