9.6 BUUCTF [GWCTF 2019]pyre

pyc文件用https://tool.lu/pyc/ 打开
然后分析源码
直接通过最后计算出的 code[] 反向即可
注意 要将 "%lf"这种转成 "\x1f"才能让python转义为字符
所以处理后的code[]:

code = [
        '\x1f','\x12','\x1d','(','0','4','\x01','\x06','\x14',
        '4',',','\x1b','U','?','o','6','*',':','\x01','D',';','%','\x13']

还有一个点 枚举ascii时 1~123的范围不够 会漏掉 '{' 所以循环上届开大点

if __name__ == '__main__':
    code = [
        '\x1f','\x12','\x1d','(','0','4','\x01','\x06','\x14',
        '4',',','\x1b','U','?','o','6','*',':','\x01','D',';','%','\x13']
    l = len(code)   
    for j in range(l-1):
        # print(j)        
        i = l-2-j
        # print(i)
        code[i] = chr(ord(code[i])^ord(code[i+1]))

    flag=""
    for i in range(l):
        for k in range(1,178):
            if ord(code[i])==(((k+i)%128)+128)%128:
                flag += chr(k)
                break

    print(flag)

最后flag: