194 lines
7.1 KiB
Python
Executable File
194 lines
7.1 KiB
Python
Executable File
#!/usr/bin/env python3
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import itertools # product, compress, combinations
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import bisect # bisect_left, insort
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import lib as LIB
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#########################################
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# GuessVigenere : Shift values around with a given keylength
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#########################################
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class GuessVigenere(object):
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def __init__(self, nums):
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self.nums = nums
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def guess(self, keylength, score_fn): # minimize score_fn
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found = []
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avg_score = 0
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for offset in range(keylength):
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bi = -1
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bs = 9999999
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for i in range(29):
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shifted = [(x - i) % 29 for x in self.nums[offset::keylength]]
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score = score_fn(shifted)
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if score < bs:
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bs = score
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bi = i
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avg_score += bs
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found.append(bi)
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return avg_score / keylength, found
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#########################################
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# GuessAffine : Find greatest common affine key
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#########################################
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class GuessAffine(object):
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def __init__(self, nums):
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self.nums = nums
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def guess(self, keylength, score_fn): # minimize score_fn
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found = []
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avg_score = 0
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for offset in range(keylength):
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candidate = (None, None)
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best = 9999999
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for s in range(29):
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for t in range(29):
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shifted = [LIB.affine_decrypt(x, (s, t))
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for x in self.nums[offset::keylength]]
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score = score_fn(shifted)
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if score < best:
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best = score
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candidate = (s, t)
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avg_score += best
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found.append(candidate)
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return avg_score / keylength, found
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#########################################
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# SearchInterrupt : Hill climbing algorithm for interrupt detection
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#########################################
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class SearchInterrupt(object):
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def __init__(self, arr, interrupt_chr): # remove all whitespace in arr
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self.single_result = False # if False, return list of equal likelihood
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self.full = arr
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self.stops = [i for i, n in enumerate(arr) if n == interrupt_chr]
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def to_occurrence_index(self, interrupts):
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return [self.stops.index(x) + 1 for x in interrupts]
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def from_occurrence_index(self, interrupts):
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return [self.stops[x - 1] for x in interrupts]
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def join(self, interrupts=[]): # rune positions, not occurrence index
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ret = []
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i = -1
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for x in interrupts:
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ret += self.full[i + 1:x]
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i = x
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return ret + self.full[i + 1:]
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# Go over the full string but only look at the first {maxdepth} interrupts.
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# Enumerate all possibilities and choose the one with the highest score.
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# If first interrupt is set, add it to the resulting set. If not, ignore it
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# Every iteration will add a single interrupt only, not the full set.
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def sequential(self, score_fn, startAt=0, maxdepth=9):
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found = [[]]
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def best_in_one(i, depth, prefix=[]):
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best_s = 0
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best_p = [] # [match, match, ...]
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irp = self.stops[i:i + depth]
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for x in itertools.product([False, True], repeat=depth):
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part = list(itertools.compress(irp, x))
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score = score_fn(self.join(prefix + part))
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if score >= best_s:
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if score > best_s or self.single_result:
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best_s = score
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best_p = [part]
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else:
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best_p.append(part)
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return best_p, best_s
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def best_in_all(i, depth):
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best_s = 0
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best_p = [] # [(prefix, [match, match, ...]), ...]
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for pre in found:
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parts, score = best_in_one(i, depth, prefix=pre)
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if score >= best_s:
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if score > best_s or self.single_result:
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best_s = score
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best_p = [(pre, parts)]
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else:
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best_p.append((pre, parts))
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return best_p, best_s
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# first step: move maxdepth-sized window over data
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i = startAt - 1 # in case loop isnt called
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for i in range(startAt, len(self.stops) - maxdepth):
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# print('.', end='')
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parts, _ = best_in_all(i, maxdepth)
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found = []
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search = self.stops[i]
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for prfx, candidates in parts:
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bitSet = False
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bitNotSet = False
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for x in candidates:
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if len(x) > 0 and x[0] == search:
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bitSet = True
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else:
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bitNotSet = True
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if bitSet and bitNotSet:
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break
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if bitSet:
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found.append(prfx + [search])
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if bitNotSet:
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found.append(prfx)
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# print('.')
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# last step: all permutations for the remaining (< maxdepth) bits
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i += 1
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remaining, score = best_in_all(i, min(maxdepth, len(self.stops) - i))
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found = [x + z for x, y in remaining for z in y]
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return score, found
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# Flip upto {maxdepth} bits anywhere in the full string.
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# Choose the bitset with the highest score and repeat.
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# If no better score found, increment number of testing bits and repeat.
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# Either start with all interrupts set (topDown) or none set.
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def genetic(self, score_fn, topDown=False, maxdepth=3):
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best = 0
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current = self.stops if topDown else []
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def evolve(lvl):
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for x in itertools.combinations(self.stops, lvl + 1):
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tmp = current[:] # [x for x in current if x not in old]
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for y in x:
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if y is None:
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continue
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elif y in current:
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tmp.pop(bisect.bisect_left(tmp, y))
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else:
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bisect.insort(tmp, y)
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yield tmp, score_fn(self.join(tmp))
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if lvl > 0:
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yield from evolve(lvl - 1)
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best = score_fn(self.join())
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level = -1 # or start directly with maxdepth - 1
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while level < maxdepth:
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print('.', end='')
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update = None
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for interrupts, score in evolve(level):
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if score > best:
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best = score
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update = interrupts
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if update:
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current = update
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continue # did optimize, so retry with same level
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level += 1
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print('.')
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# find equally likely candidates
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if self.single_result:
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return best, [current]
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all_of_them = [x for x, score in evolve(2) if score == best]
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all_of_them.append(current)
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return best, all_of_them
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# a = GuessInterrupt([2, 0, 1, 0, 14, 15, 0, 13, 24, 25, 25, 25], 0)
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# print(a.sequential(lambda x: (1.2 if len(x) == 11 else 0.1)))
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# print(a.sequential(lambda x: (1.1 if len(x) == 10 else 0.1)))
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# print(a.sequential(lambda x: (1.3 if len(x) == 9 else 0.1)))
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