crazy attack !!!!!!!!!!!

import itertools

class LFSR:

    def __init__(self, seed, feedback_positions):

        self.state = [int(bit) for bit in seed]

        self.feedback_positions = [int(pos) for pos in feedback_positions]

    def shift(self):

        feedback_bit = self.state[self.feedback_positions[0]]

        for pos in self.feedback_positions[1:]:

            feedback_bit ^= self.state[pos]

        stream_bit = self.state[-1]

        self.state = [feedback_bit] + self.state[:-1]

        return stream_bit

def combining_function(x1, x2, x3):

    return x3 if x1 == 0 else x2

def run_lfsr_for_keystream(lfsr, length):

    return [lfsr.shift() for _ in range(length)]

if __name__ == "__main__":

    provided_keystream = "1010111000011110011000101111110110101100010110011110101011011011111100111100100001011110011001011000101110100100110000011111110110100111111000101001100011011000110101011011011101111111111000001001110010100101100100110011010101111110010001110010001110110111001100100101111101110011001100001100001000010101111111110100000000001111110010101001101011000001001110011111011011011111001101011011110001001101110001100101010101101000011010000111011111111111111111011111111010111111111100011000101101000111011110011011100110010001110101010000111111101011000000000100001001111111111101111110100000000011011111101110111110011010010000011111111010000000000110000101100111010101011011011110001001100001001100111110111100111100000100000001000010111011110111111111111111111011111101000011001111001101100111111010011101100011001001110000000000001000000010100111101101101101010110000100000100110011011001011001011011100011111011111011010100111000000111000000100000001010011110110110111101111010000111000111010001110011001001110000000000000110101010101010010000000001010101011001111100000110000101000100110001110001110000001100001011110111010101111011011111111101111100101100011001111111101001111001111001000111100000110000000100000001010000010011111101101101111011110100001100011101000111001100100111000000000000011010101010101001000000000010101010110011111000001100001010001001100011100011100000011000010111101110101011110110111111111011111001011000110011111111010011110011110010001111000001100000001000000010100000100111111011011011110111101000011000111010001110011001001110000000000000110101010101010010000000001010101011001111100000110000101000100110001110001110000001100001011110111010101111011011111111101111100101100011001111111101001111001111001000111100000110000000100000001010000010"

    provided_keystream_list = [int(bit) for bit in provided_keystream]

    chunk_size = len(provided_keystream_list)

    initial_states_list2 = [f"{i:011b}" for i in range(128)]

    initial_states_list3 = [f"{i:013b}" for i in range(128)]

    feedback2 = [1, 10]

    feedback3 = [0, 2, 3, 12]

    # Precompute all possible outputs for LFSR1

    initial_states_list1 = [f"{i:07b}" for i in range(128)]

    feedback1 = [0, 6]

    lfsr1_outputs = {}

    for state in initial_states_list1:

        lfsr = LFSR(state, feedback1)

        output = tuple(run_lfsr_for_keystream(lfsr, chunk_size))

        lfsr1_outputs[output] = state

    match_found = False

    for initial_state2 in initial_states_list2:

        lfsr2 = LFSR(initial_state2, feedback2)

        e_keystream = run_lfsr_for_keystream(lfsr2, chunk_size)

        for initial_state3 in initial_states_list3:

            lfsr3 = LFSR(initial_state3, feedback3)

            f_keystream = run_lfsr_for_keystream(lfsr3, chunk_size)

            # Reconstruct d_keystream

            d_keystream = []

            conflict = False

            for i in range(chunk_size):

                if e_keystream[i] == f_keystream[i]:

                    if provided_keystream_list[i] != e_keystream[i]:

                        conflict = True

                        break

                    else:

                        d_keystream.append(None)  # Don't care

                else:

                    if provided_keystream_list[i] == e_keystream[i]:

                        d_keystream.append(1)

                    elif provided_keystream_list[i] == f_keystream[i]:

                        d_keystream.append(0)

                    else:

                        conflict = True

                        break

            if conflict:

                continue

            possible_d_keystreams = []

            indices = [i for i, bit in enumerate(d_keystream) if bit is None]

            for bits in itertools.product([0, 1], repeat=len(indices)):

                temp_keystream = d_keystream.copy()

                for idx, bit in zip(indices, bits):

                    temp_keystream[idx] = bit

                possible_d_keystreams.append(tuple(temp_keystream))

            for d_keystream_candidate in possible_d_keystreams:

                if d_keystream_candidate in lfsr1_outputs:

                    print(f"Matching keystream found!")

                    print(f"Initial state for LFSR1 (d_j): {lfsr1_outputs[d_keystream_candidate]}")

                    print(f"Initial state for LFSR2 (e_j): {initial_state2}")

                    print(f"Initial state for LFSR3 (f_j): {initial_state3}")

                    match_found = True

                    break

            if match_found:

                break

        if match_found:

            break

    if not match_found:

        print("No matching keystream found.")