NepnepxCATCTF

WEB

ez_js



Crypto

cat’s gift


:::tips
1 - 1/3 + 1/5 - 1/7 + … 是求Π/4 近似值的c语言算法 分成4份，所以是派(pie)
:::
CatCTF{pie}

盖茨比

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from Crypto.Cipher import AES
from Crypto.Util.strxor import strxor as xor
from Crypto.Util.Padding import pad
from random import *
from base64 import *
from copy import copy
from secret import data

iv=bytes([randint(0,2**8-1) for i in range(16)]) 
iva=copy(iv)
key=bytes([randint(0,2**8-1) for i in range(16)])
cipher=AES.new(key,mode=AES.MODE_ECB)
data=pad(data,16)
c=b""
for i in range(0,len(data),16):
    s=data[i:i+16].ljust(16,b"\n")
    c+=cipher.encrypt(xor(s,iv))
    iv=xor(s,c[-16:])


key=b64encode(key)
c=b64encode(c)

print(key)
print(c)



"""
b'+0zkhmid1PFjVdxSP09zSw=='
b'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'


"""

:::tips
这段代码实现了对明文数据进行加密，并使用了 AES 加密算法，使用了 ECB 模式。
它先生成了一个 16 字节的随机密钥和一个 16 字节的随机初始化向量 (IV)。然后使用这个密钥和 IV 初始化一个 AES 加密器。接着，它对明文数据进行补齐，使其长度是 16 的倍数，并将明文分块。每一块都使用相同的密钥进行加密，但是使用的 IV 是加密的前一块的输出与当前块的异或。
最后，将加密的密钥和密文进行 base64 编码，并输出。
:::

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from Crypto.Cipher import AES
from Crypto.Util.strxor import strxor as xor
from string import printable
from base64 import b64decode
from Crypto.Util.number import *

# 将密钥和密文 base64 解码
key = b64decode(b'+0zkhmid1PFjVdxSP09zSw==')
ciphertext = b64decode(b'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'
)
cipher=AES.new(key,mode=AES.MODE_ECB)
c2 = [ciphertext[i:i+16] for i in range(0,len(ciphertext),16)]
xor_s = []
xor_iv = b''
for ciphertext in c2:
    xor_s.append(cipher.decrypt(ciphertext))
    
s = b''
tiv = b'\xd4\x5d\x47\xaf\x96\xc5\xde\x2d\x96\x51\x6d\xf5\x3e\xe9\x30' 
for j in [0x99]:
    iv = tiv+long_to_bytes(j)
    trycry = ''
    for i in range(len(xor_s)):
        s = xor(xor_s[i], iv)
        iv = xor(s, c2[i])
        try:
            trycry += s.decode()
            if trycry[-1] not in printable:
                break
            trycry += ''
        except:
            break
    if 'flag' in trycry:   #查找关键字flag
        print(trycry)
        #flag{This's_why_PCBC_is_not_living}

Misc

CatCat

图片010打开检索password出密码 catflag
然后rabbit密码解密，密钥为catflag
然后base91解码
最后Ook解码



MeowMeow

010打开

:::tips
CatCTF{CAT_GOES_MEOW}
:::

Cat_Jump

010打开检索

:::tips
CatCTF{EFI_1sv3ry_funn9}
:::

miao~

foremost分离出一个音频

Audacity打开

得到key：CatCTF
DeepSound打开

1
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兽音解密 https://roar.iiilab.com/

CatchCat

打开是GPS数据

参考：https://blog.csdn.net/jwq2011/article/details/53674125
GPS路径可视化

:::tips
CatCTF{GPS_M1ao}
:::

Peekaboo

一个一个试，试出来是百里玄策

CatFlag

丢linux直接cat flag

Nepnep 祝你新年快乐啦！

REVERSE

The cat did it



0~100尝试，必出，结果 0%就出了
:::tips
CatCTF{9f1ef07877f9d85a82bd500f408b4814}
:::

CTF > 比赛Write Up
#比赛Write Up
NepnepxCATCTF
http://example.com/2023/02/09/NepnepxCATCTF/
作者
J_0k3r
发布于
2023年2月9日
许可协议
BY J_0K3R