{"url":"https://yosupo.hatenablog.com/entry/2015/08/30/231546","provider_name":"Hatena Blog","blog_url":"https://yosupo.hatenablog.com/","type":"rich","image_url":"http://cdn-ak.f.st-hatena.com/images/fotolife/y/yosupo/20150830/20150830230647.png","html":"<iframe src=\"https://hatenablog-parts.com/embed?url=https%3A%2F%2Fyosupo.hatenablog.com%2Fentry%2F2015%2F08%2F30%2F231546\" title=\"TDUCTF KeyGeneretor? 200pt writeup - \u3088\u3059\u307d\u306e\u65e5\u8a18\" class=\"embed-card embed-blogcard\" scrolling=\"no\" frameborder=\"0\" style=\"display: block; width: 100%; height: 190px; max-width: 500px; margin: 10px 0px;\"></iframe>","author_url":"https://blog.hatena.ne.jp/yosupo/","author_name":"yosupo","categories":[],"provider_url":"https://hatena.blog","published":"2015-08-30 23:15:46","height":"190","title":"TDUCTF KeyGeneretor? 200pt writeup","version":"1.0","blog_title":"\u3088\u3059\u307d\u306e\u65e5\u8a18","width":"100%","description":"\u307e\u305a\u306f\u5b9f\u884c \u306a\u308b\u307b\u3069\u3001\u3069\u3046\u306b\u304b\u3057\u30664\u3092\u5b9f\u884c\u3057\u306a\u3055\u3044\u3063\u3066\u30ef\u30b1\u306d IDA\u306b\u7a81\u3063\u8fbc\u3080 \u7d42\u3002 gdb\u3067\u30a6\u30a7\u30a4\u3059\u308b\u3068\u7c21\u5358\u306a\u6761\u4ef6\u5206\u5c90\u3060\u3063\u305f\u306e\u3067\u3001 set $pc = hoge \u3067\u7121\u7406\u3084\u308a4\u3092\u9078\u3076\u3002 4\u3092\u9078\u3076\u3068print_flag\u3068\u3044\u3046\u95a2\u6570\u306b\u98db\u3093\u3067\u3044\u305f\u306e\u3067\u5927\u52dd\u5229\u3063\u307d\u3044 \u4eba\u9593\u3092\u8210\u3081\u3066\u3044\u308b \u7d42\u3002 print_flag\u306e\u4e2d\u3092\u8210\u3081\u308b\u3088\u3046\u306b\u898b\u305f\u3051\u3069\u7279\u306b\u5909\u306a\u5206\u5c90\u306f\u7121\u3044\u3057\u3001\u5b8c\u5168\u306b\u624b\u8a70\u307e\u308a \u30d2\u30f3\u30c8\u304f\u308c\u301c\u983c\u3080\u301c\u3068\u8a00\u3063\u305f\u3089\u89e3\u6790\u3059\u308b\u5bfe\u8c61\u304c\u9055\u3046\u3088\u2764\ufe0f\u3068\u8a00\u308f\u308c\u3066\u3001\u30a2\u30c3\u3053\u308c\u306a\u3093\u3068\u304b\u304b\u3093\u3068\u304b.so\u3092\u89e3\u6790\u3059\u308b\u3084\u3064\u3060\u3063\u3066\u306a\u308b objdump \u3081\u3063\u3061\u3083\u610f\u5473\u6df1\u3063\u307d\u3044\u90e8\u5206\u304c\u51fa\u3066\u304f\u308b \u3069\u3046\u3084\u3089\u3053\u306e\u30d0\u30a4\u30c8\u5217\u306b0x6d\u3092xor\u3057\u3066\u51fa\u529b\u3057\u3066\u308b\u3063\u307d\u3044\u306e\u3067\u30dd\u2026"}