add phunkypython1 and 2

This commit is contained in:
Jacob Magnuson 2017-02-15 17:14:23 +00:00
parent c72dc03b96
commit 8777cfeafe
6 changed files with 67 additions and 0 deletions

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The other day we happened upon a dusty old laptop covered in duct tape and surrounded by several papers with notes scrawled all over them. Upon inspection, we found that the laptop contained several python files labeled `phunky`.
We've determined that each of the files contains a mini reversing challenge. The first task is simple: Find the value of `x` such that the program prints out `easyctf`.
[phunky1.py](${phunky1_py})

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phunkypython1/grader.py Normal file
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from cStringIO import StringIO
def get_flag(random):
n = random.randint(10**16, 10**19)
return n
def generate_phunky(random):
n = get_flag(random)
digs = [n + ord(t) for t in 'easyctf']
prog = 'x = 0 # REDACTED\ndigs = {}\nout = ""\nfor letter in reversed(digs):\n out = chr(letter - x) + out\nprint out'.format(str(digs))
return StringIO(prog)
def generate(random):
return dict(files={
"phunky1.py": generate_phunky
})
def grade(random, key):
n = get_flag(random)
if key.find("%d" % n) >= 0:
return True, "Nice work!"
return False, "Nope."

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author: blockingthesky
title: Phunky Python I
category: Reversing
autogen: true
programming: false
value: 30

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We stumbled across another phunky Python file. Can you find the redacted value of jkx that makes [this program](${phunky2_py}) print `True`?

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phunkypython2/grader.py Normal file
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from cStringIO import StringIO
def get_flag(random):
n = random.randint(10**16, 10**19)
return n
def generate_phunky(random):
n = get_flag(random)
n *= n - 1
n = [int(u) for u in str(n)]
primes = [2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 127, 131, 137, 139, 149, 151, 157, 163, 167, 173]
big = 1
for i in range(len(n)):
big *= primes[i] ** n[i]
prog = 'import operator\njkx = 0 # REDACTED\npork = ((12*jkx+44)/4)-(1234/617)*jkx-sum([1, 4, 7])\njkx *= pork\npp = filter(lambda g: not any(g % u == 0 for u in range(2, g)), range(2, 10000))\nb = reduce(operator.mul, (pp[i] ** int(str(jkx)[i]) for i in range(len(str(jkx)))))\nprint b == {}'.format(str(big))
return StringIO(prog)
def generate(random):
return dict(files={
"phunky2.py": generate_phunky
})
def grade(random, key):
n = get_flag(random)
if key.find("%d" % n) >= 0:
return True, "Nice work!"
return False, "Nope."

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author: blockingthesky
title: Phunky Python II
category: Reversing
autogen: true
programming: false
value: 115