{"blog_title":"Learning cyber security by playing and enjoying CTFs","author_url":"https://blog.hatena.ne.jp/M5453/","author_name":"M5453","provider_name":"Hatena Blog","title":"Daily AlpacaHack \"Compile time flag checker\" writeup","url":"https://m5453.hatenablog.com/entry/2026/07/18/110638","description":"1. \u306f\u3058\u3081\u306b \u3053\u306e\u8a18\u4e8b\u306f\u3001Daily AlpacaHack 2026/07/12\u51fa\u984c\u300cCompile time flag checker\u300d\u306ewriteup\u3067\u3059\u3002 \u3053\u306e\u554f\u984c\u306eTopic\u306f C++\u3001Category\u306fRev\u3067\u3059\u3002 \u4ee5\u4e0b\u3001\u5f53\u8a72\u51fa\u984c\u306e\u30cd\u30bf\u30d0\u30ec\u304c\u542b\u307e\u308c\u307e\u3059\u306e\u3067\u6ce8\u610f\u3057\u3066\u304f\u3060\u3055\u3044\u3002 2. Writeup 2-1. \u8a2d\u554f \u6b63\u3057\u3044\u30d5\u30e9\u30b0\u3067\u3060\u3051\u30b3\u30f3\u30d1\u30a4\u30eb\u3067\u304d\u307e\u3059\u3002 \u521d\u5fc3\u8005\u5411\u3051\u30d2\u30f3\u30c81: C++\u306e\u6a5f\u80fd \uff08\u7701\u7565\uff09 \u521d\u5fc3\u8005\u5411\u3051\u30d2\u30f3\u30c82: \u554f\u984c\u3078\u306e\u30a2\u30d7\u30ed\u30fc\u30c1 \uff08\u7701\u7565\uff09 1\u500b\u306etar.gz\u30d5\u30a1\u30a4\u30eb\u304c\u63d0\u4f9b\u3055\u308c\u3001\u305d\u306e\u4e2d\u306b\u306f\u4ee5\u4e0b\u306eC++\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3068\u30b3\u30f3\u30d1\u30a4\u30eb\u5b9f\u884c\u306e\u305f\u3081\u306e\u30b3\u30de\u30f3\u30c9\u304c\u3042\u308a\u307e\u3059\u3002 \u300cchal.cpp\u2026","blog_url":"https://m5453.hatenablog.com/","categories":[],"version":"1.0","width":"100%","provider_url":"https://hatena.blog","image_url":null,"html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fm5453.hatenablog.com%2Fentry%2F2026%2F07%2F18%2F110638\" title=\"Daily AlpacaHack &quot;Compile time flag checker&quot; writeup - Learning cyber security by playing and enjoying CTFs\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","type":"rich","published":"2026-07-18 11:06:38","height":"190"}