H&NCTF2025 - Misc、Forensic、Osint - WriteUp

 1import os
 2import re
 3import hashlib
 4
 5# 1. 构建数字 1–50 到对应 md5 值的映射
 6#    数字 <10 时使用两位格式 01-09，其余正常
 7
 8def build_md5_map():
 9    md5_map = {}
10    for i in range(1, 51):
11        # 小于10时补0
12        s = f"{i:02d}" if i < 10 else str(i)
13        h = hashlib.md5(s.encode('utf-8')).hexdigest()
14        md5_map[h] = i
15    return md5_map
16
17# 2. 主函数：遍历、筛选并重命名
18
19def rename_files_by_md5(input_dir, output_dir):
20    """
21    遍历 input_dir 下的所有.txt文件，
22    匹配文件名是否为32位小写十六进制MD5，
23    并根据映射生成 outputs 目录下对应序号的文件
24    """
25    os.makedirs(output_dir, exist_ok=True)
26    md5_map = build_md5_map()
27    pattern = re.compile(r"^[0-9a-f]{32}$")
28
29    for fname in os.listdir(input_dir):
30        if not fname.lower().endswith('.txt'):
31            continue
32
33        name = fname[:-4].strip().lower()
34        if not pattern.fullmatch(name):
35            continue
36
37        num = md5_map.get(name)
38        if num is None:
39            print(f"Warning: 未找到对应序号的MD5：{name}.txt")
40            continue
41
42        src = os.path.join(input_dir, fname)
43        dst = os.path.join(output_dir, f"{num}.txt")
44
45        with open(src, 'r', encoding='utf-8') as f_src:
46            content = f_src.read()
47        with open(dst, 'w', encoding='utf-8') as f_dst:
48            f_dst.write(content)
49
50        print(f"生成: {num}.txt")
51
52
53if __name__ == '__main__':
54    INPUT_DIR = 'txt/End/End'  # 包含 MD5 文件的目录
55    OUTPUT_DIR = 'outputs'
56    rename_files_by_md5(INPUT_DIR, OUTPUT_DIR)

 1import os
 2
 3def merge_txt_files(input_dir, output_file='merged.txt'):
 4    with open(output_file, 'w', encoding='utf-8') as outfile:
 5        for i in range(1, 51):
 6            filename = os.path.join(input_dir, f'{i}.txt')
 7            try:
 8                with open(filename, 'r', encoding='utf-8') as infile:
 9                    content = infile.read()
10                    outfile.write(content)
11                    # outfile.write('\n')  # 可选：每个文件之间加一个换行
12            except FileNotFoundError:
13                print(f'Warning: {filename} not found, skipping.')
14
15if __name__ == '__main__':
16    # 示例路径：请替换为你的目录路径
17    input_directory = 'outputs'
18    merge_txt_files(input_directory, output_file='merged.txt')

1H&NCTF{0503-丁鼻垄}

1H&NCTF{0504-东庠岛灯塔}

1H&NCTF{0504-流水码头-岚庠渡3号}