st98 の日記帳

import string
from pwn import *

def encrypt(s):
  p = process('./superencrypt')
  p.recvuntil('decrypt: ')
  p.sendline('0')
  p.recvuntil('encrypt: ')
  p.sendline(s)
  res = p.recvline()[:len(s)]
  p.close()
  return res

def find(s):
  for i, c in enumerate(s):
    if c in string.ascii_uppercase:
      return i

encrypted = 'dufhyuc>bi{{f0|;vwh<~b5p5thjq6goj}'
l = len(encrypted)
s = encrypt('A' * l)
flag = [None] * l
for i in range(l):
  j = find(encrypt('a' * i + 'A' + 'a' * (l - i - 1)))
  flag[i] = chr(ord(encrypted[j]) - ord(s[j]) + ord('A'))

print ''.join(flag)

for i in range(1,101):
    tel1l1l1l1l1l1l1lt = "REDACTED"
    import builtins, random
    l1l1l1l1l1l1l1l = getattr(builtins, "__import__")
    l1l1l1l1l1l1l1l = l1l1l1l1l1l1l1l("PIL.Image")
    l1l1l1l1l1l1l1ll1l1l1l1l1l1l1l = l1l1l1l1l1l1l1l.Image
    l1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1l = l1l1l1l1l1l1l1ll1l1l1l1l1l1l1l.new("RGB", (len(tel1l1l1l1l1l1l1lt), 1), "white")
    l1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1l = l1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1l.load()
    l1l1l1l1l1l1l1ll1l1l1l111l1l11 = 0
    for l1l1l1l1l1l1l1ll1l1l1l1l1l1l11 in tel1l1l1l1l1l1l1lt:
        l1l1l1l1l1l1l1ll1l1l1l1l1l1l11 = ord(l1l1l1l1l1l1l1ll1l1l1l1l1l1l11)
        l1l1l1l1l1l1l1ll1l1l1l1lll1l111 = random.randint(1,256)
        l1l1l1l1l1l1l1ll1l1l1l1lll1l112 = random.randint(1,256)
        l1l1l1l1l1l1l1ll1l1l1l1lll1l113 = random.randint(1,256)
        l1l1l1l1l1l1l11ll1l1l1l1lll1l111 = (l1l1l1l1l1l1l1ll1l1l1l1lll1l111/256)
        l1l1l1l1l1l1l11ll1l1l1l1lll1l112 = (l1l1l1l1l1l1l1ll1l1l1l1lll1l112/256)
        l1l1l1l1l1l1l11ll1l1l1l1lll1l113 = (l1l1l1l1l1l1l1ll1l1l1l1lll1l113/256)
        l1l121l1l1l1l11ll1l1l1l1lll1l111 = l1l1l1l1l1l1l1ll1l1l1l1l1l1l11*l1l1l1l1l1l1l11ll1l1l1l1lll1l111
        l1l121l1l1l1l11ll1l1l1l1lll1l112 = l1l121l1l1l1l11ll1l1l1l1lll1l111*l1l1l1l1l1l1l11ll1l1l1l1lll1l112
        l1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1l[l1l1l1l1l1l1l1ll1l1l1l111l1l11,0] = (l1l1l1l1l1l1l1ll1l1l1l1lll1l111, l1l1l1l1l1l1l1ll1l1l1l1lll1l112, round(l1l121l1l1l1l11ll1l1l1l1lll1l112*10))
        l1l1l1l1l1l1l1ll1l1l1l111l1l11 += 1
    l1l1l1l1l1l1l1ll1l1l1l1l1l1l1ll1l1l1l1l1l1l1l.save("out"+str(i)+".png")

for i in range(1,101):
    flag = "REDACTED"
    import builtins, random
    __import__ = getattr(builtins, "__import__")
    Image = __import__("PIL.Image")
    Image = Image.Image
    im = Image.new("RGB", (len(flag), 1), "white")
    pix = im.load()
    x = 0
    for c in flag:
        c = ord(c)
        r = random.randint(1,256)
        g = random.randint(1,256)
        b = random.randint(1,256)
        rr = (r/256)
        gg = (g/256)
        bb = (b/256)
        xx = c*rr
        yy = xx*gg
        pix[x,0] = (r, g, round(yy*10))
        x += 1
    im.save("out"+str(i)+".png")

import string
from PIL import Image

h = []

for i in range(1, 101):
  im = Image.open('encoded/out{}.png'.format(i))
  pix = im.load()
  w, _ = im.size
  h.append([pix[x, 0] for x in range(w)])

flag = ''
f = lambda pix: min(round(ord(c) * (pix[x][0] / 256) * (pix[x][1] / 256) * 10), 255) == pix[x][2]
for x in range(38):
  for c in string.printable:
    if len(list(filter(f, h))) > 90:
      flag += c
      break
  else:
    flag += '?'

print(flag)

from decimal import *
from binascii import hexlify as h
from binascii import unhexlify as u
from math import ceil as e
from sys import argv as y
D,w,O,z,j,b,X,v,o,U=Decimal,getcontext,chr,len,str,int,long,str,len,hex
def q():
    w().prec+=5;L,t,s,n,k,d,K=0,D(3),3,1,0,0,24
    while s!=L:L=s;n,k=n+k,k+8;d,K=d+K,K+32;t=(t*n)/d;s+=t
    w().prec-=5
    return +s
Q=q()
def s(x):
    w().prec+=5;i,L,s,f,n,S=1,0,x,1,x,1;
    while s!=L:L=s;i+=2;f*=i*(i-1);n*=x*x;S*=-1;s+=n/f*S
    w().prec-=5
    return +s
def E(S):
    w().prec=b(e(o(S)*2.40823996531))+1;a=(lambda:[D(O(48)+O(46)+j((lambda:X(h(S),4+4*4-4))()))*Q-Q/D(2),j(v(D(5.2))+S)+v(U(z(j(e(2.71)))))][0])()
    return j((lambda P:U(X(v((D(1)-s(a)*s(a+D(1)-D(7-5)+D(3)-D(6-4))).sqrt())[2:])))(lambda:[-2,X(j(v(1)),13)][1]))[2:-1]
A=h("Usage: "+y[0]+" <string>") if o(y)!=2 else E(y[1])
f=open("out.txt",O(b('7'+'7',(4**4)/4/4)))
f.write(u(A[:-1] if z(A)%2==1 else A))
f.close()

from decimal import *
from binascii import hexlify
from binascii import unhexlify
from math import ceil
from sys import argv

def pi():
  getcontext().prec += 5
  L, t, s, n, k, d, K = 0, Decimal(3), 3, 1, 0, 0, 24
  while s != L:
    L = s
    n, k = n + k, k + 8
    d, K = d + K, K + 32
    t = (t * n) / d
    s += t
  getcontext().prec -= 5
  return +s

PI = pi()

def sin(x):
  getcontext().prec += 5
  i, L, s, f, n, S = 1, 0, x, 1, x, 1;
  while s != L:
    L = s
    i += 2
    f *= i * (i - 1)
    n *= x * x
    S *= -1
    s += n / f * S
  getcontext().prec -= 5
  return +s

def cos(x):
  return (Decimal(1) - sin(x) * sin(x)).sqrt().copy_abs()

def encode(S):
  getcontext().prec = int(ceil(len(S) * 2.40823996531)) + 1
  a = Decimal('0.' + str(long(hexlify(S), 16))) * PI - PI / Decimal(2)
  d = str(cos(a))[2:]
  return str(hex(long(d)))[2:-1]

A = hexlify("Usage: " + argv[0] + " <string>") if len(argv) != 2 else encode(argv[1])
with open("out.txt", "w") as f:
  f.write(unhexlify(A[:-1] if len(A) % 2 == 1 else A))

import sys
from decimal import *
from dmath import *
from math import ceil

s = 'out.txt' if len(sys.argv) < 2 else sys.argv[1]
with open(s, 'rb') as f:
  x = f.read()

l = len(x)
p = int(ceil(l * 2.40823996531))
getcontext().prec = p + 1
D = Decimal
PI = pi()

x = D('0.' + str(long(x.encode('hex') + 'f', 16)))
print hex(long(str((-acos(x) + PI / D(2)) / PI)[2:2 + p]))[2:-1].decode('hex')

import re
from collections import Counter

with open('flags.txt') as f:
  s = f.read().splitlines()

t = ''.join(line[0] for line in s)
x = Counter({k: t.count(k) for k in s[0]})
print ''.join(c for c, _ in x.most_common())

import re

with open('image4.txt') as f:
  s = f.read()

p = re.compile(r"""
It's\ not\ TPCTF{.+}\ though|
TPCTF{.+}\ is\ not\ the\ flag|
The\ flag\ isn't\ TPCTF{.+}|
Fun\ fact:\ TPCTF{.+}\ is\ a\ fake\ flag|
Fun\ fact:\ TPCTF{.+}\ starts\ with\ TPCTF|
Fun\ fact:\ TPCTF{.+}\ has\ 18\ letters\ in\ between\ the\ braces|
Fun\ fact:\ All\ the\ letters\ in\ TPCTF{.+}\ are\ lowercase\ except\ for\ the\ TPCTF\ at\ the\ start|
Clarence\ Lam\ is\ a\ TPCTF\ organizer\ and\ he\ thinks\ the\ flag\ is\ TPCTF{.+}\ but\ it\ isn't|
Clarence\ Lam\ is\ a\ TPCTF\ organizer\ and\ favorite\ string\ is\ TPCTF{.+}|
Clarence\ Lam\ is\ a\ TPCTF\ organizer\ and\ he\ doesn't\ like\ strings\ of\ text\ like\ TPCTF{.+}|
Clarence\ Lam\ is\ a\ TPCTF\ organizer\ and\ his\ least\ favorite\ string\ is\ TPCTF{.+}|
Clarence\ Lam\ is\ a\ TPCTF\ organizer\ and\ the\ flag\ isn't\ TPCTF{.+}|
Clarence\ Lam\ is\ part\ of\ a\ group\ that\ organized\ TPCTF\ and\ the\ flag\ is\ not\ quite\ TPCTF{.+}|
Clarence\ Lam\ writes\ TPCTF\ problems,\ some\ of\ which\ contain\ flags,\ such\ as\ TPCTF{.+}|
Clarence\ Lam\ wrote\ a\ few\ problems\ for\ TPCTF\ and\ his\ least\ favorite\ string\ of\ text\ isn't\ not\ TPCTF{.+}|
Did\ you\ know\ that\ Clarence\ Lam's\ favorite\ command\ is\ TPCTF{.+}';\ DROP\ TABLE\ flags;\ --\ \?\ Of\ course\ you\ didn't|
""", re.X)
s = s.split('. ')
s = filter(lambda x: 'TPCTF{' in x, s)
s = filter(lambda x: not p.search(x), s)
print '\n'.join(sorted(list(s))[:10])