Full solution script for Confidence 2019 Teaser

solv.py

import sys

original = [0,0,0,0,0,0,0,0,2   ,0,3,2,1,1,0,   0,
            0,0,0,0,0,0,0,1,0   ,3,4,2,3,0,0xff,0,
            0,0,0,0,0,0,1,0,2   ,2,1,3,0,1,0   ,0,
            0,0,0,0,0,0,0,2,0   ,1,0,0,0,0,0   ,0,
            0,0,0,0,0,0,0,0,0xfe,0,0,0,0,0,0   ,0]

import importlib
a=importlib.import_module(sys.argv[1])


import string

def solve():
	print('#'+str(len(a.solution)))
	new_sol = []
	sol_len = len(a.solution)
	while sol_len > 0:
		partial = a.solution[0]
		if partial in a.solution:
			a.solution.remove(partial)
			sol_len = len(a.solution)
		for c in xrange(0x30,0x7d+1):
			if chr(c) not in string.digits and chr(c) not in string.ascii_lowercase and chr(c) != '}':
				continue 
			idx = 72
			if original[idx] != 0xfe:
				break	
			flag = original[:]
			correct = True
			p = (c << a.shifts) + partial
			clone = p
			for k in range(a.bit_len):
				b = p & 3
				if b == 0:
					idx -= 17
				elif b == 1:
					idx -= 15
				elif b == 2:
					idx += 15
				elif b == 3:
					idx += 17
				if idx < 0:
					idx += 16
				if idx < 0 or idx > len(flag):
					correct = False
				if flag[idx] == 0 or flag[idx] == 0xfe:
					correct = False
					break #we can't step on zero's
				flag[idx] -= 1

				p >>= 2
			if correct:# and idx==30:
				#print("#[+] Potential successful num: {0:x}".format(clone))
				new_sol.append(clone)
	return new_sol

print("bit_len={0}".format(a.bit_len+4))
print("shifts={0}".format(a.shifts+8))
print("solution=["+','.join('{:#04x}'.format(x) for x in solve())+"]")