SvATTT2017 - Onion

solvedyou.py

file = open('solveme.txt','r').read().split('\n')
enlarge = 0x636f

def brute(line, goal):
	# print line, goal
	for x in range(0,512):
		for y in range(0,512):
			t_x = x + enlarge
			t_y = y + enlarge
			result = 0
			for i in range(0,len(line),2):
				symbol = line[i]
				coeff,_x,_y = [int(k) for k in line[i+1]]
				# print symbol, coeff,x,_x,y,_y
				if symbol == '+':
					result += coeff*(t_x**_x)*(t_y**_y)
				elif symbol == '-':
					result -= coeff*(t_x**_x)*(t_y**_y)
				else:
					print 'error'
			if result == goal:
				return (x,y)
	return (-1,-1)

for xx in range(len(file)):
	line = file[xx].split()
	_len = len(line)
	result = 0
	board = ['+']
	if _len == 0:
		continue
	for i in range(_len):
		if line[i] == '==':
			continue
		if i == _len-1:
			result = int(line[i])
			break
		if i%2 == 0:
			temp = line[i].split('*')
			coeff, x, y = 0,0,0
			if len(temp) == 3:
				coeff, x, y = temp
			elif 'x' in line[i]:
				coeff, x = temp
			else:
				coeff, y = temp
			try:
				x = x.split('^')[1]
			except:
				pass
			try:
				y = y.split('^')[1]
			except:
				pass
			board += [(coeff,x,y)]
		else:
			board += [line[i]]
	print brute(board, result)

ss.py

ss = [361, 293, 84, 138, 197, 419, 189, 404, 216, 177, 383, 432, 344, 366, 87, 273, 419, 229, 254, 225, 349, 438, 140, 205, 107, 498, 163, 249, 206, 220, 105, 311, 315, 475, 44, 55, 355, 261, 434, 216, 249, 303, 60, 150, 493, 19, 291, 297, 184, 220, 206, 360, 303, 218, 301, 390, 343, 411, 420, 416, 70, 288, 400, 335]
size = 9
def reverse(byte, n):
    return (byte<<n)%(1<<size)|(byte>>(size-n))

flag = ''
for i in range(len(ss)-1):
    ss[i] = reverse(ss[i],(i+3) % size)
    ss[i] = reverse(ss[i],i % size)
    flag += bin(ss[i])[2:].zfill(9)
    
print hex(int(flag,2))[2:-1].decode('hex')