hgame 2021部分wp

Re

pypy

  1. 题目所给的时Python字节码，如下
  4           0 LOAD_GLOBAL              0 (input)
              2 LOAD_CONST               1 ('give me your flag:\n')
              4 CALL_FUNCTION            1
              6 STORE_FAST               0 (raw_flag)

  5           8 LOAD_GLOBAL              1 (list)
             10 LOAD_FAST                0 (raw_flag)
             12 LOAD_CONST               2 (6)
             14 LOAD_CONST               3 (-1)
             16 BUILD_SLICE              2
             18 BINARY_SUBSCR
             20 CALL_FUNCTION            1
             22 STORE_FAST               1 (cipher)

  6          24 LOAD_GLOBAL              2 (len)
             26 LOAD_FAST                1 (cipher)
             28 CALL_FUNCTION            1
             30 STORE_FAST               2 (length)

  8          32 LOAD_GLOBAL              3 (range)
             34 LOAD_FAST                2 (length)
             36 LOAD_CONST               4 (2)
             38 BINARY_FLOOR_DIVIDE
             40 CALL_FUNCTION            1
             42 GET_ITER
        >>   44 FOR_ITER                54 (to 100)
             46 STORE_FAST               3 (i)

  9          48 LOAD_FAST                1 (cipher)
             50 LOAD_CONST               4 (2)
             52 LOAD_FAST                3 (i)
             54 BINARY_MULTIPLY
             56 LOAD_CONST               5 (1)
             58 BINARY_ADD
             60 BINARY_SUBSCR
             62 LOAD_FAST                1 (cipher)
             64 LOAD_CONST               4 (2)
             66 LOAD_FAST                3 (i)
             68 BINARY_MULTIPLY
             70 BINARY_SUBSCR
             72 ROT_TWO
             74 LOAD_FAST                1 (cipher)
             76 LOAD_CONST               4 (2)
             78 LOAD_FAST                3 (i)
             80 BINARY_MULTIPLY
             82 STORE_SUBSCR
             84 LOAD_FAST                1 (cipher)
             86 LOAD_CONST               4 (2)
             88 LOAD_FAST                3 (i)
             90 BINARY_MULTIPLY
             92 LOAD_CONST               5 (1)
             94 BINARY_ADD
             96 STORE_SUBSCR
             98 JUMP_ABSOLUTE           44

 12     >>  100 BUILD_LIST               0
            102 STORE_FAST               4 (res)

 13         104 LOAD_GLOBAL              3 (range)
            106 LOAD_FAST                2 (length)
            108 CALL_FUNCTION            1
            110 GET_ITER
        >>  112 FOR_ITER                26 (to 140)
            114 STORE_FAST               3 (i)

 14         116 LOAD_FAST                4 (res)
            118 LOAD_METHOD              4 (append)
            120 LOAD_GLOBAL              5 (ord)
            122 LOAD_FAST                1 (cipher)
            124 LOAD_FAST                3 (i)
            126 BINARY_SUBSCR
            128 CALL_FUNCTION            1
            130 LOAD_FAST                3 (i)
            132 BINARY_XOR
            134 CALL_METHOD              1
            136 POP_TOP
            138 JUMP_ABSOLUTE          112

 15     >>  140 LOAD_GLOBAL              6 (bytes)
            142 LOAD_FAST                4 (res)
            144 CALL_FUNCTION            1
            146 LOAD_METHOD              7 (hex)
            148 CALL_METHOD              0
            150 STORE_FAST               4 (res)

 16         152 LOAD_GLOBAL              8 (print)
            154 LOAD_CONST               6 ('your flag: ')
            156 LOAD_FAST                4 (res)
            158 BINARY_ADD
            160 CALL_FUNCTION            1
            162 POP_TOP
            164 LOAD_CONST               0 (None)
            166 RETURN_VALUE

# your flag: 30466633346f59213b4139794520572b45514d61583151576638643a
  1. 将字节码翻译为Python代码，参考
raw_flag = input('give me your flag:\n')

cipher = list(raw_flag[6:-1])

length = len(cipher)

for i in range(length // 2):
    cipher[2*i], cipher[2*i + 1] = cipher[2*i + 1], cipher[2*i]

rse = []
for i in range(length):
    res.append(ord(cipher[i]) ^ i)

res = bytes(res).hex()
print('your flag: ', res)

# your flag: 30466633346f59213b4139794520572b45514d61583151576638643a
  1. 解密代码为
res = '30466633346f59213b4139794520572b45514d61583151576638643a'
res_b = bytes.fromhex(res)
print(res_b)

cipher = []
for i in range(len(res_b)):
    cipher.append(chr(res_b[i] ^ i))
print(cipher)

for i in range(len(cipher) // 2):
    cipher[2*i], cipher[2*i + 1] = cipher[2*i + 1], cipher[2*i]

print(cipher)
flag = ""
for i in cipher:
    flag += i
print(flag)
  1. 结果为G00dj0&_H3r3-I$Y@Ur_$L@G!~!~

Crypto

まひと

  1. 下载文件并打开，时morse电码，解码得到
86/109/108/110/90/87/53/108/99/109/85/116/84/71/108/114/97/84/112/57/86/109/116/116/100/107/112/105/73/84/70/89/100/69/70/52/90/83/70/111/99/69/48/120/101/48/48/114/79/88/104/120/101/110/74/85/84/86/57/79/97/110/53/106/85/109/99/48/101/65/61/61
  1. 十进制转ASCII
VmlnZW5lcmUtTGlraTp9VmttdkpiITFYdEF4ZSFocE0xe00rOXhxenJUTV9Oan5jUmc0eA==
  1. base64解码
Vigenere-Liki:}VkmvJb!1XtAxe!hpM1{M+9xqzrTM_Nj~cRg4x
  1. 维吉尼亚加密，且密钥为Liki，解密
}KccnYt!1NlPpu!zeE1{C+9pfrhLB_Fz~uGy4n
  1. 因为明文中是包含hgame的，因此必有移位，遍历以下移位后结果中包含hgame的
def caesar(c, n):
    tmp = ""
    for i in c:
        if 'a' <= i <= 'z':
            if ord(i) + n > ord('z'):
                tmp += chr((ord(i) - ord('a') + n) % 26 + ord('a'))
            else:
                tmp += chr(ord(i) + n)
        elif 'A' <= i <= 'Z':
            if ord(i) + n > ord('Z'):
                tmp += chr((ord(i) - ord('A') + n) % 26 + ord('A'))
            else:
                tmp += chr(ord(i) + n)
        else:
            tmp += i
    return tmp


c = "}KccnYt!1NlPpu!zeE1{C+9pfrhLB_Fz~uGy4n"

for i in range(2, 26):
    res = caesar(c, i)
    if 'h' in res and 'g' in res and 'a' in res and 'm' in res and 'e' in res:
        print(i, res)

结果为移位13时包含，字符串为}XppaLg!1AyCch!mrR1{P+9cseuYO_Sm~hTl4a
6. 根据括号的位置可以判断还有一层栅栏密码，尝试发现每组字数6，得到}!!Pu~X1m+YhpAr9OTpyRc_laC1sS4Lc{emagh字符串反转一下得到flag
hgame{cL4Ss1Cal_cRypTO9rAphY+m1X~uP!!}

WhitegiveRSA

确实白给

  1. 先大数分解得到p和q分别为857504083339712752489993810777和1029224947942998075080348647219
  2. python代码如下
import gmpy2
from Crypto.Util.number import long_to_bytes

e = 65537
c = 747831491353896780365654517748216624798517769637260742155527
n = 882564595536224140639625987659416029426239230804614613279163
p = 857504083339712752489993810777
q = 1029224947942998075080348647219

phn = (p-1) * (q-1)
d = gmpy2.invert(e, phn)
print(d)

m = pow(c, d, n)
print(long_to_bytes(m)

hgame{w0w~yOU_kNoW+R5@!}

MISC

Week-1

不起眼压缩包的养成的方法

  1. 下载得到一个jpg文件，用010Editor打开，发现末尾有
  2. 因此推测jpg中包含zip文件，且口令为8位数字
  3. 用foremost分离出zip文件，并使用Advanced Archive Password Recovery暴力破解，得到口令为70415155
  4. 成功解压缩，得到两个文件
  5. 发现plain.zip中还有个NO PASSWORD.txt且没有更多的提示，因此应该是利用这个文本文件进行已知明文攻击，参考
  6. 在ARCHPR中添加待解密的文件和我们自己压缩的文件，最初在此遇到了报错
  7. 因此换成winRAR进行压缩，在压缩前查看了已有的待破解压缩包的属性有
  8. 因此将NO PASSWORD.txt以同样的方式进行压缩
  9. 现在可以成功开始
  10. 最终得到口令为C8uvP$DP
  11. 解压plain.zip得到其中的flag.zip，由于没有更多的提示，所以用010Editor查看以下，得到以下信息
  12. 将这段值复制出来转成ASCII即可得到flag为hgame{2IP_is_Usefu1_and_Me9umi_i5_W0r1d}

Galaxy

  1. 下载pcapng文件，拖到wireshark看下，根据提示有一张星空壁纸，所以先搜索有无png
  2. 双击这条，然后找到PNG文件流所在位置，复制hex流
  3. 用Python将其转为文件
import binascii

m= '将复制好的hex流粘贴至此'
f=open('flag.png', 'wb')
f.write(binascii.a2b_hex(m))
  1. 打开得到的png文件却提示
  2. 用010Editor打开提示CRC校验错误，看一下图片宽高，因此可能是高度有错，通过CRC爆破即可，这里参考以前的一篇博客，只需改下图片名即可
import struct
import binascii
from Crypto.Util.number import bytes_to_long

img = open("flag.png", "rb").read()

for i in range(0xFFFF):
    stream = img[12:20] + struct.pack('>i', i) + img[24:29]
    crc = binascii.crc32(stream)
    if crc == bytes_to_long(img[29:33]):
         print(hex(i))
  1. 输出结果1000，因此将高度改为1000即可看到flag

hgame{Wh4t_A_W0nderfu1_Wa11paper}

Word RE:MASTER

  1. 解压缩发现两个文件，maimai.docx需要口令，因此推测first中有关键信息

    查看文件属性也可以发现提示
  2. binwalk查看
  3. binwalk -e first.docx分离文件，发现有个password.xml
  4. 打开后得到
+++++ +++[- >++++ ++++< ]>+++ +.<++ +[->+ ++<]> ++.<+ ++[-> +++<] >+.<+ ++[-> ---<] >-.++ ++++. <+++[ ->--- <]>-. +++.+ .++++ ++++. <+++[ ->--- <]>-- ----. +.--- --..+ .++++ +++++ .<+++ [->-- -<]>- ----- .<
  1. Brainfuck解密，得到DOYOUKNOWHIDDEN?
  2. 用其成功打开maimai.docx
  3. 请教大佬，发现是snow隐写参考
  4. 将docx导出txt文件
  5. SNOW.EXE -C maimai.txt

hgame{Cha11en9e_Whit3_P4ND0R4_P4R4D0XXX}

Week-2

Hallucigenia

  1. 用Stegsolve打开，发现了一个被反色的QR二维码
  2. 保存这个二维码并反色，得到
  3. 扫描得到
gmBCrkRORUkAAAAA+jrgsWajaq0BeC3IQhCEIQhCKZw1MxTzSlNKnmJpivW9IHVPrTjvkkuI3sP7bWAEdIHWCbDsGsRkZ9IUJC9AhfZFbpqrmZBtI+ZvptWC/KCPrL0gFeRPOcI2WyqjndfUWlNj+dgWpe1qSTEcdurXzMRAc5EihsEflmIN8RzuguWq61JWRQpSI51/KHHT/6/ztPZJ33SSKbieTa1C5koONbLcf9aYmsVh7RW6p3SpASnUSb3JuSvpUBKxscbyBjiOpOTq8jcdRsx5/IndXw3VgJV6iO1+6jl4gjVpWouViO6ih9ZmybSPkhaqyNUxVXpV5cYU+Xx5sQTfKystDLipmqaMhxIcgvplLqF/LWZzIS5PvwbqOvrSlNHVEYchCEIQISICSZJijwu50rRQHDyUpaF0y///p6FEDCCDFsuW7YFoVEFEST0BAACLgLOrAAAAAggUAAAAtAAAAFJESEkNAAAAChoKDUdOUIk=
posted @ 2021-02-03 12:16  vict0r  阅读(559)  评论(0)  编辑  收藏  举报