{"id":620,"date":"2023-02-23T10:56:38","date_gmt":"2023-02-23T02:56:38","guid":{"rendered":"https:\/\/scutvk.cn\/?p=620"},"modified":"2023-02-23T15:53:02","modified_gmt":"2023-02-23T07:53:02","slug":"snort%e8%af%ad%e6%b3%95%e8%a7%84%e5%88%99-%e5%8d%95%e4%bd%8d-distance-within-depth-offset","status":"publish","type":"post","link":"https:\/\/scutvk.cn\/?p=620","title":{"rendered":"Snort\u8bed\u6cd5\u89c4\u5219 | \u5355\u4f4d distance within depth offset"},"content":{"rendered":"\n

offset\u504f\u79fb\u91cf\u5355\u4f4d\u8bf4\u660e<\/strong><\/p>\n\n\n\n

\u5728\u8ba1\u7b97\u673a\u4e2d\uff0c\u4e00\u4e2a\u5b57\u7b26\u5360\u7528\u7684\u5b57\u8282\u6570\u53d6\u51b3\u4e8e\u6240\u4f7f\u7528\u7684\u5b57\u7b26\u7f16\u7801\u65b9\u5f0f\u3002\u5728 ASCII \u7f16\u7801\u4e2d\uff0c\u6bcf\u4e2a\u5b57\u7b26\u5360\u7528 1 \u4e2a\u5b57\u8282\uff0c\u800c\u5728 Unicode \u7f16\u7801\u4e2d\uff0c\u6bcf\u4e2a\u5b57\u7b26\u5360\u7528 2 \u4e2a\u6216 4 \u4e2a\u5b57\u8282\uff0c\u5177\u4f53\u53d6\u51b3\u4e8e\u6240\u4f7f\u7528\u7684\u7f16\u7801\u683c\u5f0f\u3002<\/p>\n\n\n\n

\u5728 Snort \u89c4\u5219\u4e2d\uff0c\u504f\u79fb\u91cf\u6307\u7684\u662f\u8981\u68c0\u6d4b\u7684\u6570\u636e\u4ece\u6570\u636e\u7684\u8d77\u59cb\u4f4d\u7f6e\u5f00\u59cb\u7684\u5b57\u8282\u6570\uff0c\u800c\u4e0d\u662f\u5b57\u7b26\u6570\u3002\u56e0\u6b64\uff0c\u5982\u679c\u4f7f\u7528\u7684\u662f ASCII \u7f16\u7801\uff0c\u5e76\u4e14\u8981\u4ece\u7b2c 13 \u4e2a\u5b57\u7b26\u5f00\u59cb\u8fdb\u884c\u5339\u914d\uff0c\u90a3\u4e48\u504f\u79fb\u91cf\u5c31\u662f 12\uff08\u56e0\u4e3a\u5b57\u7b26\u8ba1\u6570\u4ece 0 \u5f00\u59cb\uff09\u3002<\/p>\n\n\n\n

\u5982\u679c\u4f7f\u7528\u7684\u662f Unicode \u7f16\u7801\uff0c\u504f\u79fb\u91cf\u9700\u8981\u4e58\u4ee5\u6bcf\u4e2a\u5b57\u7b26\u6240\u5360\u7528\u7684\u5b57\u8282\u6570\uff0c\u4f8b\u5982\uff0c\u5982\u679c\u4f7f\u7528 UTF-16 \u7f16\u7801\uff0c\u5e76\u4e14\u8981\u4ece\u7b2c 13 \u4e2a\u5b57\u7b26\u5f00\u59cb\u8fdb\u884c\u5339\u914d\uff0c\u90a3\u4e48\u504f\u79fb\u91cf\u5c31\u662f 24\uff08\u56e0\u4e3a\u6bcf\u4e2a\u5b57\u7b26\u5360\u7528 2 \u4e2a\u5b57\u8282\uff09\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

1 offset<\/strong><\/p>\n\n\n\n

\u4f8b\u5b501\uff1a<\/p>\n\n\n\n

content:\"GET\"; offset:0;<\/code><\/pre>\n\n\n\n
\u8fd9\u662fSnort\u89c4\u5219\u4e2d\u7684\u4e00\u4e2a\u9009\u9879\uff0c\u7528\u4e8e\u6307\u5b9a\u8981\u68c0\u6d4b\u7684\u6570\u636e\u7684\u5185\u5bb9\u3001\u504f\u79fb\u91cf\u548c\u5176\u4ed6\u7279\u5f81\u3002<\/p>\n\n\n\n
    \n
  • content<\/code>\uff1a\u7528\u4e8e\u6307\u5b9a\u8981\u68c0\u6d4b\u7684\u6570\u636e\u7684\u5185\u5bb9\u3002<\/li>\n\n\n\n
  • \"GET\"<\/code>\uff1a\u662f\u8981\u68c0\u6d4b\u7684\u5177\u4f53\u5185\u5bb9\uff0c\u8fd9\u91cc\u662f\u68c0\u6d4bHTTP\u8bf7\u6c42\u4e2d\u662f\u5426\u5305\u542b”GET”\u3002<\/li>\n\n\n\n
  • offset<\/code>\uff1a\u7528\u4e8e\u6307\u5b9a\u4ece\u6570\u636e\u5f00\u59cb\u5904\u7684\u504f\u79fb\u91cf\u3002<\/li>\n\n\n\n
  • 0<\/code>\uff1a\u8fd9\u91cc\u662f\u6307\u4ece\u6570\u636e\u7684\u8d77\u59cb\u4f4d\u7f6e\u5f00\u59cb\u8fdb\u884c\u5339\u914d\u3002<\/li>\n<\/ul>\n\n\n\n
    \u56e0\u6b64\uff0c\u8be5\u89c4\u5219\u5c06\u68c0\u6d4bHTTP\u8bf7\u6c42\u4e2d\u662f\u5426\u5305\u542b”GET”\uff0c\u5e76\u4e14\u5c06\u4ece\u8bf7\u6c42\u7684\u5f00\u59cb\u4f4d\u7f6e\u8fdb\u884c\u5339\u914d\u3002\u4f8b\u5982\uff0c\u4ee5\u4e0bHTTP\u8bf7\u6c42\u5c06\u5339\u914d\u8be5\u89c4\u5219\uff1a<\/p>\n\n\n\n
    GET \/index.html HTTP\/1.1\nHost: example.com<\/code><\/pre>\n\n\n\n
    \u800c\u4ee5\u4e0bHTTP\u8bf7\u6c42\u5219\u4e0d\u4f1a\u5339\u914d\u8be5\u89c4\u5219\uff1a<\/p>\n\n\n\n
    POST \/submit-form HTTP\/1.1\nHost: example.com<\/code><\/pre>\n\n\n\n
    \u8bf7\u6ce8\u610f\uff0c\u8fd9\u53ea\u662fSnort\u89c4\u5219\u4e2d\u7684\u4e00\u90e8\u5206\uff0c\u8fd8\u9700\u8981\u5c06\u5176\u4e0e\u5176\u4ed6\u9009\u9879\u7ec4\u5408\u4f7f\u7528\uff0c\u4f8b\u5982http_method<\/code>\u9009\u9879\u4ee5\u9650\u5b9a\u5339\u914dHTTP\u8bf7\u6c42\u65b9\u6cd5\u3002<\/p>\n\n\n\n
    \u4f8b\u5b502\uff1a<\/p>\n\n\n\n
    content:\"GET\"; offset:0; content:\"downloads\"; offset:10;<\/code><\/pre>\n\n\n\n
    \u8fd9\u4e2a Snort \u89c4\u5219\u5c06\u5339\u914d\u5305\u542b\u5b57\u7b26\u4e32 “GET” \u548c “downloads” \u7684\u6570\u636e\u6d41\u3002\u5177\u4f53\u6765\u8bf4\uff0c\u5b83\u4f1a\u4ece\u6570\u636e\u6d41\u7684\u8d77\u59cb\u4f4d\u7f6e\uff08\u504f\u79fb\u91cf\u4e3a 0\uff09\u5f00\u59cb\u67e5\u627e “GET” \u5b57\u7b26\u4e32\uff0c\u7136\u540e\u4ece\u7b2c 10 \u4e2a\u5b57\u8282\u5f00\u59cb\u67e5\u627e “downloads” \u5b57\u7b26\u4e32\u3002<\/p>\n\n\n\n
    GET \/downloads\/index.html HTTP\/1.1\nHost: www.example.com<\/code><\/pre>\n\n\n\n
    2 depth<\/strong><\/p>\n\n\n\n
    content:\"GET\"; depth:3;<\/code><\/pre>\n\n\n\n
    \u8fd9\u4e2a Snort \u89c4\u5219\u5c06\u4ece\u6570\u636e\u6d41\u7684\u8d77\u59cb\u4f4d\u7f6e\u5f00\u59cb\u67e5\u627e “GET” \u5b57\u7b26\u4e32\uff0c\u4f46\u53ea\u4f1a\u67e5\u627e\u524d\u4e09\u4e2a\u5b57\u8282\u3002\u5177\u4f53\u6765\u8bf4\uff0c\u8fd9\u4e2a\u89c4\u5219\u4f1a\u5728\u6570\u636e\u6d41\u7684\u524d\u4e09\u4e2a\u5b57\u8282\u4e2d\u67e5\u627e “GET” \u5b57\u7b26\u4e32\u3002<\/p>\n\n\n\n
    \u4f8b\u5982\uff0c\u8003\u8651\u4ee5\u4e0b HTTP \u8bf7\u6c42\uff1a<\/p>\n\n\n\n
    GET \/index.html HTTP\/1.1\nHost: www.example.com<\/code><\/pre>\n\n\n\n
    \u5728\u8fd9\u4e2a\u8bf7\u6c42\u4e2d\uff0c”GET” \u51fa\u73b0\u5728\u8bf7\u6c42\u884c\u7684\u7b2c\u4e00\u4e2a\u5355\u8bcd\u4e2d\uff0c\u56e0\u6b64\u7b26\u5408 Snort \u89c4\u5219\u7684\u5339\u914d\u6761\u4ef6\u3002\u4f46\u662f\u7531\u4e8e\u89c4\u5219\u7684\u6df1\u5ea6\u9650\u5236\u4e3a 3\uff0c\u56e0\u6b64 Snort \u53ea\u4f1a\u67e5\u627e\u8bf7\u6c42\u884c\u7684\u524d\u4e09\u4e2a\u5b57\u8282\uff0c\u5373 “GET”\u3002\u7531\u4e8e “GET” \u51fa\u73b0\u5728\u8fd9\u4e2a\u4f4d\u7f6e\uff0c\u56e0\u6b64 Snort \u5c06\u89e6\u53d1\u89c4\u5219\u7684\u52a8\u4f5c\uff08\u4f8b\u5982\u751f\u6210\u8b66\u62a5\u6216\u8bb0\u5f55\u65e5\u5fd7\uff09\u3002<\/p>\n\n\n\n
    3 distance<\/strong><\/p>\n\n\n\n
    distance\u8be5\u5173\u952e\u5b57\u7c7b\u4f3c\u4e8eoffset\uff0c\u90fd\u662f\u8ddd\u79bb\u54ea\u591a\u5c11\u4e2a\u5b57\u8282\u5f00\u59cb\u641c\u7d22\uff0c\u4f46\u662fdistance\u662f\u76f8\u5bf9\u4e8e\u524d\u9762\u7684\u5185\u5bb9\u5339\u914d\uff08\u4e8e\u6b64\u6848\u4f8b\u4e2d\u662fcontent:”GET”<\/strong>\uff09\uff0c\u800coffset\u662f\u8ddd\u79bb\u6709\u6548\u8d1f\u8f7d\/\u7f13\u51b2\u533a\u7684\u5f00\u5934\uff08\u4e5f\u5c31\u662f\u4ece\u5168\u6587\u76840\u5b57\u8282\u5f00\u59cb\uff09\u3002\u7b80\u5355\u6765\u8bf4\uff0cdistance\u5b83\u544a\u8bc9 Snort \u5728\u67e5\u627e\u6b64\u5185\u5bb9\u5339\u914d\u4e4b\u524d\u5728\u6700\u540e\u4e00\u4e2a\u5185\u5bb9\u5339\u914d\u540e\u67e5\u770b\u8df3\u8fc7 X<\/em> \u4e2a\u5b57\u8282\u3002<\/p>\n\n\n\n
    content:\"GET\"; content:\"downloads\"; distance:10;<\/code><\/pre>\n\n\n\n
    \u8fd9\u6761 Snort \u89c4\u5219\u7528\u4e8e\u68c0\u6d4b\u6570\u636e\u6d41\u4e2d\u662f\u5426\u5b58\u5728 “GET” \u548c “downloads” \u8fd9\u4e24\u4e2a\u5173\u952e\u5b57\uff0c\u5e76\u4e14\u5b83\u4eec\u4e4b\u95f4\u7684\u8ddd\u79bb\u4e3a 10 \u4e2a\u5b57\u8282\u4ee5\u5185\u3002<\/p>\n\n\n\n
    \u5177\u4f53\u6765\u8bf4\uff0cSnort \u5728\u6570\u636e\u6d41\u4e2d\u641c\u7d22 “GET” \u8fd9\u4e2a\u5173\u952e\u5b57\uff0c\u7136\u540e\u7ee7\u7eed\u5f80\u540e\u641c\u7d22\u76f4\u5230\u627e\u5230 “downloads” \u8fd9\u4e2a\u5173\u952e\u5b57\u3002\u5728\u8fd9\u4e2a\u8fc7\u7a0b\u4e2d\uff0cSnort \u5c06\u68c0\u67e5\u8fd9\u4e24\u4e2a\u5173\u952e\u5b57\u4e4b\u95f4\u7684\u8ddd\u79bb\u662f\u5426\u5c0f\u4e8e\u7b49\u4e8e 10 \u4e2a\u5b57\u8282\u3002\u5982\u679c\u6ee1\u8db3\u6761\u4ef6\uff0c\u8be5\u89c4\u5219\u5c06\u88ab\u89e6\u53d1\uff0c\u8868\u793a\u6570\u636e\u6d41\u4e2d\u5b58\u5728\u5339\u914d\u8be5\u89c4\u5219\u7684\u5185\u5bb9\u3002<\/p>\n\n\n\n
    4 within<\/strong><\/p>\n\n\n\n
    within\u548cdepth\u7c7b\u4f3c\uff0cdepth \u548c within \u662f Snort \u89c4\u5219\u4e2d\u7528\u4e8e\u9650\u5236\u641c\u7d22\u6570\u636e\u6d41\u7684\u53c2\u6570\u3002\u5b83\u4eec\u7684\u533a\u522b\u5982\u4e0b\uff1a<\/p>\n\n\n\n
      \n
    • depth\uff1adepth \u53c2\u6570\u7528\u4e8e\u9650\u5236\u641c\u7d22\u6570\u636e\u6d41\u7684\u6df1\u5ea6\u3002\u5728\u89c4\u5219\u4e2d\u6307\u5b9a depth \u53c2\u6570\u540e\uff0cSnort \u53ea\u4f1a\u641c\u7d22\u6570\u636e\u6d41\u7684\u524d N \u4e2a\u5b57\u8282\u3002\u8fd9\u6709\u52a9\u4e8e\u63d0\u9ad8\u89c4\u5219\u7684\u6027\u80fd\u5e76\u51cf\u5c11\u8bef\u62a5\uff0c\u56e0\u4e3a\u5728\u6df1\u5ea6\u9650\u5236\u4e4b\u524d\u505c\u6b62\u641c\u7d22\u6570\u636e\u6d41\u53ef\u4ee5\u51cf\u5c11\u4e0d\u5fc5\u8981\u7684\u5904\u7406\u3002\u5982\u679c\u6df1\u5ea6\u8bbe\u7f6e\u5f97\u592a\u5c0f\uff0c\u53ef\u80fd\u4f1a\u9519\u8fc7\u4e0e\u89c4\u5219\u5339\u914d\u7684\u6570\u636e\u3002\u56e0\u6b64\uff0c\u5e94\u8be5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u8c03\u6574\u6df1\u5ea6\u53c2\u6570\uff0c\u4ee5\u786e\u4fdd\u89c4\u5219\u53ef\u4ee5\u51c6\u786e\u5730\u5339\u914d\u5173\u952e\u5b57\u3002<\/li>\n\n\n\n
    • within\uff1awithin \u53c2\u6570\u7528\u4e8e\u9650\u5236\u641c\u7d22\u5173\u952e\u5b57\u51fa\u73b0\u7684\u8303\u56f4\u3002\u5728\u89c4\u5219\u4e2d\u6307\u5b9a within \u53c2\u6570\u540e\uff0cSnort \u5c06\u5728\u8ddd\u79bb\u5173\u952e\u5b57\u4e4b\u540e\u7684 N \u4e2a\u5b57\u8282\u5185\u641c\u7d22\u89c4\u5219\u3002\u5982\u679c\u5173\u952e\u5b57\u51fa\u73b0\u5728 within \u53c2\u6570\u6307\u5b9a\u7684\u8303\u56f4\u5185\uff0c\u5219\u89c4\u5219\u5c06\u89e6\u53d1\u3002\u8fd9\u6709\u52a9\u4e8e\u63d0\u9ad8\u89c4\u5219\u7684\u51c6\u786e\u6027\u5e76\u51cf\u5c11\u8bef\u62a5\uff0c\u56e0\u4e3a\u9650\u5236\u641c\u7d22\u8303\u56f4\u53ef\u4ee5\u51cf\u5c11\u4e0d\u5fc5\u8981\u7684\u5904\u7406\u3002\u5982\u679c within \u53c2\u6570\u8bbe\u7f6e\u5f97\u592a\u5c0f\uff0c\u53ef\u80fd\u4f1a\u9519\u8fc7\u4e0e\u89c4\u5219\u5339\u914d\u7684\u6570\u636e\u3002\u56e0\u6b64\uff0c\u5e94\u8be5\u6839\u636e\u5177\u4f53\u60c5\u51b5\u8c03\u6574 within \u53c2\u6570\uff0c\u4ee5\u786e\u4fdd\u89c4\u5219\u53ef\u4ee5\u51c6\u786e\u5730\u5339\u914d\u5173\u952e\u5b57\u3002<\/li>\n<\/ul>\n\n\n\n
      \u5047\u5982distance\u5927\u4e8ewithin\u4f1a\u600e\u4e48\u6837\uff1f<\/strong><\/p>\n\n\n\n
      \u5982\u679c\u4f7f\u7528distance\u53c2\u6570\u9650\u5b9a\u7684\u4f4d\u7f6e\u4e0ewithin\u53c2\u6570\u9650\u5b9a\u7684\u957f\u5ea6\u8303\u56f4\u76f8\u6bd4\u8f83\uff0cdistance\u5927\u4e8ewithin\uff0c\u90a3\u4e48\u5339\u914d\u89c4\u5219\u5c06\u4f1a\u65e0\u6548\u3002<\/p>\n\n\n\n
      \u4f8b\u5982\uff0c\u4ee5\u4e0b\u89c4\u5219\uff1a<\/p>\n\n\n\n
      alert tcp any any -> any any (msg:\"Test\"; content:\"abc\"; distance:20; within:10;)\n<\/code><\/pre>\n\n\n\n
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