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[原创]KCTF 2023 第六题 至暗时刻
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发表于: 2023-9-17 23:28
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找到程序算法入口
调试运行到这里崩溃了
观察调用栈，发现运行在内存中的一段代码，提取代码
解析输入的代码sub_447
联想调用处的代码，猜测可能有个数独
solve脚本：
11230A2CD3C31CA32E0D707D38E0743531F80F726C1D133B3A914E2F034B1D63BB17F34428E2A31B038C25E0FA2BF2301053752062AA16E20A2FC1971730E90823D01A724B0CA19B0652811541480B80943AE27E13122C30C120
import numpy as np
def decode_sudoku(encoded_sudoku_data):
"""
解码数独布局，将其从16进制字符串转换为9x9矩阵。
"""
sudoku_board = np.zeros((9, 9), dtype=int)
for i in range(0, len(encoded_sudoku_data), 3):
hex_triplet = encoded_sudoku_data[i:i+3]
decimal_value = int(hex_triplet, 16)
ones_digit, tens_digit, hundreds_digit = decimal_value % 10, (
decimal_value // 10) % 10, (decimal_value // 100) % 10
sudoku_board[tens_digit, ones_digit] = hundreds_digit
return sudoku_board
def is_valid_move(board, row, col, num):
"""
检查在数独板的特定位置放置一个数字是否有效。
"""
return not (num in board[row] or num in board[:, col] or num in board[row//3*3:row//3*3 + 3, col//3*3:col//3*3 + 3])
def solve_sudoku(board):
"""
使用回溯算法解决数独问题。
"""
for row in range(9):
for col in range(9):
if board[row, col] == 0:
for num in range(1, 10):
if is_valid_move(board, row, col, num):
board[row, col] = num
if solve_sudoku(board):
return True
board[row, col] = 0
return False
return True
def convert_solution_to_hex_string(original_board, solved_board):
"""
将解决方案转换为指定的十六进制字符串格式。
"""
hex_string = ''
for row in range(9):
for col in range(9):
if original_board[row, col] == 0:
decimal_number = solved_board[row, col] * 100 + row * 10 + col
hex_number = hex(decimal_number)[2:].upper().zfill(3)
hex_string += hex_number
return hex_string
def rearrange_hex_string(hex_string_solution, correct_order_str):
"""
使用指定的正确顺序重新排列十六进制字符串解决方案。
"""
correct_order_list = [int(correct_order_str[i:i+2])
for i in range(0, len(correct_order_str), 2)]
new_array = [None] * 256
for i in range(0, len(hex_string_solution), 3):
hex_chunk = hex_string_solution[i:i+3]
decimal_value = int(hex_chunk, 16)
index_value = (decimal_value % 10) + (decimal_value // 10 %
10) + 8 * (decimal_value // 10 % 10)
new_array[index_value] = hex_chunk
final_hex_string_solution = ''.join(
new_array[i] for i in correct_order_list if new_array[i] is not None)
return final_hex_string_solution
# 主程序encoded_sudoku_data = "3201382652D139C0E22132DF1BC2212EA0991650A229B36436823D0B13D51E6"
sudoku_board = decode_sudoku(encoded_sudoku_data)
sudoku_board_copy = sudoku_board.copy()
is_solvable = solve_sudoku(sudoku_board_copy)
hex_string_solution = convert_solution_to_hex_string(
sudoku_board, sudoku_board_copy)
correct_order_str = "677116575313142309154604431859253431473963507533496829080645035455771774602058076430276921790210013736267644383505517280"
final_hex_string_solution = rearrange_hex_string(
hex_string_solution, correct_order_str)
print(sudoku_board, is_solvable, hex_string_solution, final_hex_string_solution)
import numpy as np
def decode_sudoku(encoded_sudoku_data):
"""
解码数独布局，将其从16进制字符串转换为9x9矩阵。
"""
sudoku_board = np.zeros((9, 9), dtype=int)
for i in range(0, len(encoded_sudoku_data), 3):
hex_triplet = encoded_sudoku_data[i:i+3]
decimal_value = int(hex_triplet, 16)
ones_digit, tens_digit, hundreds_digit = decimal_value % 10, (
decimal_value // 10) % 10, (decimal_value // 100) % 10
sudoku_board[tens_digit, ones_digit] = hundreds_digit
return sudoku_board
def is_valid_move(board, row, col, num):
"""
检查在数独板的特定位置放置一个数字是否有效。
"""
return not (num in board[row] or num in board[:, col] or num in board[row//3*3:row//3*3 + 3, col//3*3:col//3*3 + 3])
def solve_sudoku(board):
"""
使用回溯算法解决数独问题。
"""
for row in range(9):
for col in range(9):
if board[row, col] == 0:
for num in range(1, 10):
if is_valid_move(board, row, col, num):
board[row, col] = num
if solve_sudoku(board):
return True
[招生]科锐逆向工程师培训(2024年11月15日实地，远程教学同时开班, 第51期)
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