{"id":956,"date":"2022-02-06T11:35:40","date_gmt":"2022-02-06T03:35:40","guid":{"rendered":"https:\/\/www.zhiwanyuzhou.com\/?p=956"},"modified":"2022-05-26T22:49:00","modified_gmt":"2022-05-26T14:49:00","slug":"%e5%b7%a5%e4%b8%9a%e4%bf%a1%e6%81%af%e5%ae%89%e5%85%a8%e6%8a%80%e8%83%bd%e5%a4%a7%e8%b5%9b2020-%e6%b5%8e%e5%8d%97%e7%ab%99-iot%e9%a2%98%e7%9b%ae%e8%a7%a3%e9%a2%98%e6%80%9d%e8%b7%af","status":"publish","type":"post","link":"https:\/\/www.zhiwanyuzhou.com\/index.php\/2022\/02\/06\/%e5%b7%a5%e4%b8%9a%e4%bf%a1%e6%81%af%e5%ae%89%e5%85%a8%e6%8a%80%e8%83%bd%e5%a4%a7%e8%b5%9b2020-%e6%b5%8e%e5%8d%97%e7%ab%99-iot%e9%a2%98%e7%9b%ae%e8%a7%a3%e9%a2%98%e6%80%9d%e8%b7%af\/","title":{"rendered":"\u5de5\u4e1a\u4fe1\u606f\u5b89\u5168\u6280\u80fd\u5927\u8d5b2020-\u6d4e\u5357\u7ad9-IoT\u9898\u76ee\u89e3\u9898\u601d\u8def"},"content":{"rendered":"\n

IoT\u9898\u76ee<\/a>\uff0c\u539f\u9898\u63cf\u8ff0<\/p>\n\n\n\n

\u4e00\u53f0\u5947\u602a\u7684\u5355\u7247\u673a\u4e0a\u8fd0\u884c\u7740\u5947\u602a\u7684\u7a0b\u5e8f\uff0c\u8bf7\u60a8\u5e2e\u52a9\u8c03\u8bd5\u76f8\u5173\u7a0b\u5e8f\u3002Flag\u683c\u5f0f\u4e3a\uff1aflag{}<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u5206\u6790\u73af\u5883<\/p>\n\n\n\n

Ubuntu 20.04
qemu 6.2.0
Ghidra 10.1<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u9996\u5148\u62ff\u5230\u9898\u76ee\uff0c\u89e3\u538b\u540e\u662f\u4e00\u4e2a\u540d\u53ebmain\u7684\u6587\u4ef6\uff0c\u4f7f\u7528file\u547d\u4ee4\u8bc6\u522b\u5176\u7c7b\u578b\u4e3aELF\u7a0b\u5e8f\uff0cCPU\u67b6\u6784\u662fRISC-V\u7684\u3002<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n
RISC-V\uff08\u53d1\u97f3\u4e3a\u201crisk-five\u201d\uff09\u662f\u4e00\u4e2a\u57fa\u4e8e\u7cbe\u7b80\u6307\u4ee4\u96c6\uff08RISC\uff09\u539f\u5219\u7684\u5f00\u6e90\u6307\u4ee4\u96c6\u67b6\u6784\uff08ISA\uff09\u3002
\u4e0e\u5927\u591a\u6570\u6307\u4ee4\u96c6\u76f8\u6bd4\uff0cRISC-V\u6307\u4ee4\u96c6\u53ef\u4ee5\u81ea\u7531\u5730\u7528\u4e8e\u4efb\u4f55\u76ee\u7684\uff0c\u5141\u8bb8\u4efb\u4f55\u4eba\u8bbe\u8ba1\u3001\u5236\u9020\u548c\u9500\u552eRISC-V\u82af\u7247\u548c\u8f6f\u4ef6\uff0c\u8be5\u9879\u76ee2010\u5e74\u59cb\u4e8e\u52a0\u5dde\u5927\u5b66\u4f2f\u514b\u5229\u5206\u6821\u3002<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u65e2\u7136\u77e5\u9053\u4e86\u5176CPU\u67b6\u6784\uff0c\u53ef\u4ee5\u8bd5\u7740\u4f7f\u7528qemu\u6a21\u62df\u8fd0\u884cELF\u6587\u4ef6\uff0c\u9996\u5148\u5b89\u88c5qemu\u73af\u5883<\/p>\n\n\n\n

sudo apt install gcc make libglib2.0-dev libpixman-1-dev ninja-build
wget https:\/\/download.qemu.org\/qemu-6.2.0.tar.xz
cd qemu-6.2.0
.\/configure --target-list=riscv64-softmmu,riscv64-linux-user
make
sudo make install<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u5b89\u88c5\u597dqemu\u73af\u5883\u540e\uff0c\u76f4\u63a5\u4f7f\u7528qemu-riscv64\u547d\u4ee4\u8fd0\u884cmain\u7a0b\u5e8f\uff0c\u542f\u52a8\u7a0b\u5e8f\u540e\u53ef\u4ee5\u8fdb\u884c\u8f93\u5165\uff0c\u7ecf\u8fc7\u6d4b\u8bd5\u5f53\u8f93\u5165\u7684\u5b57\u7b26\u4e32\u957f\u5ea6\u4e0d\u4e3a20\u4e2a\u5b57\u8282\u5c06\u76f4\u63a5\u9000\u51fa\uff0c\u5f53\u5b57\u7b26\u4e32\u957f\u5ea6\u7b49\u4e8e20\u4e2a\u5b57\u8282\u65f6\uff0c\u5982\u679c\u4e0d\u5339\u914d\u6b63\u786e\u7684\u7b54\u6848\u4f1a\u63d0\u793a\u201cYou Lose!\u201d\u3002<\/p>\n\n\n\n

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

\u90a3\u4e48\u8fd9\u65f6\u5019\u5c31\u5f97\u9006\u5411\u5206\u6790\u4e86\uff0c\u53ef\u4ee5\u4f7f\u7528\u53cd\u6c47\u7f16\u5de5\u5177\uff0c\u7531\u4e8eRISC-V\u8fd9\u79cdCPU\u67b6\u6784\u6bd4\u8f83\u65b0\uff0c\u7ecf\u8fc7\u6d4b\u8bd5\u9700\u8981\u4f7f\u7528\u65b0\u7248\u7684\u53cd\u7f16\u5de5\u5177\uff0c\u65e7\u7248\u7684\u5de5\u5177\u5f88\u591a\u90fd\u65e0\u6cd5\u652f\u6301\uff0c\u8fd9\u91cc\u4f7f\u7528\u4e86Ghidra 10.1<\/a> \u8fd9\u4e2a\u7248\u672c\u7684\u5de5\u5177\u3002<\/p>\n\n\n\n

Ghidra \u662f\u7531\u7f8e\u56fd\u56fd\u5bb6\u5b89\u5168\u5c40\uff08NSA\uff0cNational Security Agency\uff09\u7684\u7814\u7a76\u7406\u4e8b\u4f1a\u4e3a NSA \u7684\u7f51\u7edc\u5b89\u5168\u4efb\u52a1\u5f00\u53d1\u7684\u8f6f\u4ef6\u9006\u5411\u5de5\u7a0b\uff08SRE\uff09\u6846\u67b6\uff0c\u5b83\u6709\u52a9\u4e8e\u5206\u6790\u6076\u610f\u4ee3\u7801\u548c\u75c5\u6bd2\u7b49\u6076\u610f\u8f6f\u4ef6\uff0c\u5e76\u53ef\u4ee5\u8ba9\u7f51\u7edc\u5b89\u5168\u4e13\u4e1a\u4eba\u5458\u66f4\u597d\u5730\u4e86\u89e3\u5176\u7f51\u7edc\u548c\u7cfb\u7edf\u4e2d\u7684\u6f5c\u5728\u6f0f\u6d1e\u3002
\u4f7f\u7528\u7684\u65f6\u5019\u9700\u8981\u63d0\u524d\u5b89\u88c5JAVA\u73af\u5883\uff0c\u5173\u4e8e\u5982\u4f55\u914d\u7f6eJAVA\u73af\u5883\u53ef\u4ee5\u81ea\u884c\u641c\u7d22\u3002<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u4f7f\u7528\u5de5\u5177\u5206\u6790main\u6587\u4ef6\uff0c\u80fd\u591f\u6b63\u786e\u8bc6\u522b\u5176CPU\u67b6\u6784<\/p>\n\n\n\n

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

\u70b9\u51fbOK\u540e\uff0c\u5f39\u51fa\u4e00\u4e2a\u81ea\u52a8\u5206\u6790\u5bf9\u8bdd\u6846\uff0c\u70b9\u51fbYes\u5f00\u59cb\u5206\u6790<\/p>\n\n\n\n

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

\u9009\u62e9\u9ed8\u8ba4\u7684\u5206\u6790\u9879\uff0c\u70b9\u51fbAnalysze<\/p>\n\n\n\n

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

\u7ecf\u8fc7\u4e00\u4f1a\u5c31\u80fd\u5206\u6790\u5b8c\u6bd5\uff0c\u8fd9\u65f6\u5019\u770b\u5230\u5de6\u8fb9\u6709\u4e00\u4e2aSymbol Tree\u7684\u7a97\u53e3\uff0c\u8fd9\u91cc\u663e\u793a\u4e86\u51fd\u6570\u3001\u53d8\u91cf\u7b49\u7b49\u6807\u8bc6\u7b26\u3002<\/p>\n\n\n\n

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

\u4e00\u822c\u6765\u8bf4\u5206\u6790\u4e00\u4e2aELF\u7a0b\u5e8f\uff0c\u53ef\u4ee5\u4ecemain\u51fd\u6570\u5165\u624b\uff0c\u90a3\u4e48\uff0c\u5728Symbol Tree\u7684\u7a97\u53e3\u4e0b\u9762\u7684Filter\u67e5\u8be2\u6846\u67e5\u627e\u662f\u5426\u6709main\u51fd\u6570<\/p>\n\n\n\n

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

\u9009\u62e9Exports\u5bfc\u51fa\u8868\u7684main\u51fd\u6570\uff0cListing\u7a97\u53e3\u662f\u663e\u793a\u53cd\u6c47\u7f16\u4ee3\u7801\uff0cDecompile\u7a97\u53e3\u662f\u53cd\u6c47\u7f16\u7684\u4f2aC\u4ee3\u7801<\/p>\n\n\n\n

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

\u4f2a\u4ee3\u7801\u5982\u4e0b\u6240\u793a<\/p>\n\n\n\n

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

\u7ecf\u8fc7\u9759\u6001\u5206\u6790\u53ef\u4ee5\u77e5\u9053\u5176\u57fa\u672c\u903b\u8f91<\/p>\n\n\n\n

1\u3001\u957f\u5ea6\u8981\u6c4220\u5b57\u8282
2\u3001\u8f93\u5165\u7684\u5185\u5bb9\u7ecf\u8fc7\u201c\u5f02\u6216\u201d\u4e0e\u6b63\u786e\u7b54\u6848\u5404\u4e2a\u5b57\u7b26\u5339\u914d<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u73b0\u5728\u9700\u8981\u5904\u7406\u4e00\u4e0b\u5f02\u6216\u7684\u6570\u7ec4xor\u3001cyt\uff0c\u53cc\u51fb\u4f2a\u4ee3\u7801\u7684xor\u8fdb\u5165\u6c47\u7f16\u4ee3\u7801\uff0c\u53ef\u4ee5\u77e5\u9053\u6570\u7ec4\u662f4\u4e2a\u5b57\u8282\u4e3a1\u7ec4\u7684<\/p>\n\n\n\n

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

\u53f3\u952e\u9009\u62e9\u6700\u5f00\u59cbundefined\u5b57\u7b26\uff0c\u9009\u62e9Data -> dword\u4f7f\u5176\u5b9a\u4e49\u4e3a4\u4e2a\u5b57\u8282\u53d8\u91cf<\/p>\n\n\n\n

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

\u76ee\u524d\u53d8\u6210ddw\u5f62\u5f0f\uff08dword\uff09<\/p>\n\n\n\n

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

\u540c\u6837\u53f3\u952e\u9009\u62e9ddw\u5b57\u7b26\u4e32\uff0c\u9009\u62e9Data -> Create Array\u4f7f\u5176\u5b9a\u4e49\u4e3a\u4e00\u4e2a\u6570\u7ec4<\/p>\n\n\n\n

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

\u56e0\u4e3a\u5bf9\u6bd4\u7684\u5b57\u7b26\u4e32\u957f\u5ea6\u4e3a20\uff0c\u90a3\u4e48\u5728\u8fd9\u91cc\u53ef\u4ee5\u8bbe\u5b9a\u5176\u503c\u4e3a20<\/p>\n\n\n\n

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

\u8bbe\u5b9a\u540e\uff0cxor\u6570\u7ec4\u5982\u4e0b<\/p>\n\n\n\n

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

cyt\u6570\u7ec4\u540c\u7406\u53ef\u4ee5\u8bbe\u5b9a\u4e3a\u6570\u7ec4<\/p>\n\n\n\n

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

\u6839\u636e\u5f02\u6216\u7684\u89c4\u5219<\/p>\n\n\n\n

A ^ B = C \u53ef\u4ee5\u5f97\u5230 A ^ C = B<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u90a3\u4e48\u7f16\u5199\u4ee3\u7801\u8fdb\u884c\u9a8c\u8bc1\uff0c\u8fd9\u91cc\u4f7f\u7528python\u8fdb\u884c\u5feb\u901f\u7f16\u7801<\/p>\n\n\n\n

#\/usr\/bin\/python

cyt = [
0xF9,   0x95,   0x11E, 0x84,
0x43,   0x11E, 0x148, 0x186,
0x164, 0x108, 0x159, 0xDE,
0xBF,   0x78,   0x1E3, 0xC8,
0x154, 0x1FB, 0x9E,   0x104
]
xor = [
0x9F,   0xF9,    0x17F,  0xE3,
0x38,   0x146, 0x127,  0x1D4,
0x13B, 0x141, 0x16C, 0x81,
0xEC,   0x48,   0x1BC, 0x8D,
0x135, 0x188,  0xE7,  0x179
]

inputstr = \"\"
for i in range(20):
    inputstr += chr(cyt[i] ^ xor[i])
print(inputstr)<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

\u6253\u5370\u51fa\u7ed3\u679c\u4e3a<\/p>\n\n\n\n

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

\u8fd0\u884cmain\u7a0b\u5e8f\uff0c\u8f93\u5165\u201cflag{XoR_I5_S0_Easy}\u201d\uff0c\u63d0\u793a\u6b63\u786e\uff01<\/p>\n\n\n\n

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

\u53c2\u8003\u94fe\u63a5\uff1a<\/p>\n\n\n\n

https:\/\/writeup.ctfhub.com\/Challenge\/2020\/%E5%B7%A5%E4%B8%9A%E4%BF%A1%E6%81%AF%E5%AE%89%E5%85%A8%E6%8A%80%E8%83%BD%E5%A4%A7%E8%B5%9B\/%E6%B5%8E%E5%8D%97%E7%AB%99\/tRBwdk3Fhndm4UVjpAYQHy.html<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

IoT\u9898\u76ee\uff0c\u539f\u9898\u63cf\u8ff0 \u4e00\u53f0\u5947\u602a\u7684\u5355\u7247\u673a\u4e0a\u8fd0\u884c\u7740\u5947\u602a\u7684\u7a0b\u5e8f\uff0c\u8bf7\u60a8\u5e2e\u52a9\u8c03\u8bd5\u76f8\u5173\u7a0b\u5e8f\u3002Flag\u683c\u5f0f\u4e3a\uff1aflag{} \u5206\u6790\u73af\u5883 Ubuntu 20.04qemu 6.2.0Ghidra 10.1 \u9996\u5148\u62ff\u5230\u9898\u76ee\u2026<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[23],"tags":[],"blocksy_meta":{"styles_descriptor":{"styles":{"desktop":"","tablet":"","mobile":""},"google_fonts":[],"version":5}},"_links":{"self":[{"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/posts\/956"}],"collection":[{"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/comments?post=956"}],"version-history":[{"count":5,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/posts\/956\/revisions"}],"predecessor-version":[{"id":1168,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/posts\/956\/revisions\/1168"}],"wp:attachment":[{"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/media?parent=956"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/categories?post=956"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.zhiwanyuzhou.com\/index.php\/wp-json\/wp\/v2\/tags?post=956"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}