\u68c0\u67e5\u4ee3\u7801\u662f\u5426\u5b58\u5728\u6574\u6570\u64cd\u4f5c\u5b89\u5168\u6f0f\u6d1e <\/p>\n
\u53d1\u5e03\u65e5\u671f : 09\/02\/2004 | \u66f4\u65b0\u65e5\u671f : 09\/02\/2004 <\/p>\n
Michael Howard
Secure Windows Initiative <\/p>\n
\u6458\u8981\uff1a<\/b> Michael Howard \u63d0\u51fa\u5173\u4e8e\u6574\u6570\u64cd\u4f5c\u5b89\u5168\u6f0f\u6d1e\u7684\u95ee\u9898\uff0c\u5e76\u4e14\u9610\u8ff0\u53ef\u4ee5\u7528\u6765\u4fdd\u62a4\u81ea\u5df1\u5e94\u7528\u7a0b\u5e8f\u7684\u5b89\u5168\u6027\u8ba1\u5212\u3002 <\/p>\n
\u5f88\u591a\u5e74\u4ee5\u524d\uff0c\u5f88\u5c11\u6709\u4eba\u542c\u8bf4\u8fc7\u6574\u6570\u6ea2\u51fa\u653b\u51fb\uff0c\u4f46\u73b0\u5728\u597d\u50cf\u6bcf\u9694\u51e0\u5929\u5b83\u5c31\u4f1a\u51fa\u73b0\u4e00\u79cd\u65b0\u7684\u5f62\u5f0f\u3002\u4e0b\u9762\u7684\u7b80\u77ed\u5217\u8868\u5c31\u662f\u5728\u6700\u8fd1\u51e0\u4e2a\u6708\u5185\u53d1\u73b0\u7684\u4e00\u4e9b\u6574\u6570\u6ea2\u51fa\u7684\u5b89\u5168\u6027\u9519\u8bef\uff1a <\/p>\n
- \n
- \n
Sun RPC xdr_array <\/a><\/p>\n
- \n
OpenSSH authentication <\/a><\/p>\n
- \n
Apache Chunked Encoding <\/a><\/p>\n
- \n
Microsoft JScript <\/a><\/p>\n
- \n
FreeBSD socket and system calls <\/a><\/p>\n
- \n
Snort TCP Packet Reassembly <\/a><\/p>\n<\/li>\n<\/ul>\n
\u5728\u672c\u6708\u7684\u4e13\u680f\u4e2d\uff0c\u6211\u5c06\u9610\u8ff0\u8fd9\u4e9b\u9519\u8bef\u662f\u5982\u4f55\u51fa\u73b0\u7684\uff0c\u5982\u4f55\u5728\u4ee3\u7801\u4e2d\u641c\u5bfb\u5b83\u4eec\u4ee5\u53ca\u5982\u4f55\u4fee\u590d\u5b83\u4eec\u3002 <\/p>\n
\u5728\u8fdb\u5165\u5230\u672c\u6587\u7684\u6b63\u9898\u4e4b\u524d\uff0c\u6211\u975e\u5e38\u9ad8\u5174\u7684\u5ba3\u5e03\u201cWriting Secure Code\u201d\u63a5\u6536\u5230\u4e86\u5728 2003 \u5e74 4 \u6708\u4e8e San Francisco \u53ec\u5f00\u7684 RSA Security Conference \u7684\u201cConference Award for Industry Innovation\u201d\u3002 <\/p>\n
\u73b0\u5728\uff0c\u56de\u5230\u6574\u6570\u653b\u51fb\u95ee\u9898\u5427\uff01 <\/p>\n
\u6211\u4e0d\u60f3\u89e3\u91ca\u4ec0\u4e48\u662f\u6574\u6570\uff0c\u6211\u5047\u8bbe\u60a8\u77e5\u9053\u5b83\u4eec\u662f\u4ec0\u4e48\uff0c\u5e76\u4e14\u77e5\u9053\u6709\u4e24\u79cd\u7c7b\u578b\uff08\u6709\u7b26\u53f7\u548c\u65e0\u7b26\u53f7\uff09\uff0c\u5176\u4e2d\u5f53\u503c\u662f\u8d1f\u6570\u65f6\uff0c\u6709\u7b26\u53f7\u6574\u6570\u7684\u9ad8\u4f4d\u8bbe\u7f6e\u4e3a 1\uff0c\u8fd9\u662f\u5bf9 2 \u6c42\u8865\u7b97\u6cd5\u7684\u7ed3\u679c\u3002\u60a8\u4e5f\u77e5\u9053\u6574\u6570\u5927\u5c0f\u5404\u6709\u4e0d\u540c\uff0c\u6700\u5e38\u89c1\u7684\u957f\u5ea6\u4e3a 64 \u4f4d\u300132 \u4f4d\u300116 \u4f4d\u548c 8 \u4f4d\u7684\u6574\u6570\u3002\u8fd9\u5c31\u662f\u6211\u6240\u8bf4\u7684\u5173\u4e8e\u6574\u6570\u7684\u5168\u90e8\u5185\u5bb9\uff0c\u5bf9\u4e8e\u672c\u6587\u800c\u8a00\uff0c\u5982\u679c\u60a8\u77e5\u9053\u8fd9\u4e9b\u77e5\u8bc6\u5c31\u8db3\u591f\u4e86\u3002 <\/p>\n
\u6709\u4e09\u79cd\u4e3b\u8981\u6574\u6570\u64cd\u4f5c\u53ef\u4ee5\u5bfc\u81f4\u5b89\u5168\u6027\u6f0f\u6d1e\uff1a <\/p>\n
- \n
- \n
\u4e0a\u6ea2\u548c\u4e0b\u6ea2 <\/p>\n
- \n
\u6709\u7b26\u53f7\u4e0e\u65e0\u7b26\u53f7\u7684\u9519\u8bef <\/p>\n
- \n
\u622a\u65ad <\/p>\n<\/li>\n<\/ul>\n
\u53d6\u51b3\u4e8e\u5b83\u4eec\u81ea\u5df1\u7684\u60c5\u51b5\uff0c\u8fd9\u4e9b\u95ee\u9898\u53ef\u80fd\u4e0d\u4f1a\u4ea7\u751f\u5b89\u5168\u6027\u9519\u8bef\u3002\u4f46\u662f\uff0c\u5982\u679c\u60a8\u7684\u4ee3\u7801\u663e\u793a\u6709\u4e00\u4e2a\u6216\u591a\u4e2a\u8fd9\u6837\u7684\u95ee\u9898\uff0c\u5e76\u4e14\u60a8\u7684\u4ee3\u7801\u4f1a\u64cd\u4f5c\u5185\u5b58\uff0c\u90a3\u4e48\u4ea7\u751f\u7f13\u51b2\u533a\u6ea2\u51fa\u9519\u8bef\u6216\u5e94\u7528\u7a0b\u5e8f\u6545\u969c\u7684\u53ef\u80fd\u6027\u5c31\u4f1a\u589e\u52a0\u3002\u8ba9\u6211\u4eec\u4ed4\u7ec6\u67e5\u770b\u4e00\u4e0b\u6bcf\u4e00\u9879\u3002 <\/p>\n
\u4e0a\u6ea2\u548c\u4e0b\u6ea2<\/h5>\n
\u5feb\u901f\u770b\u4e00\u4e0b\u8fd9\u6bb5\u4ee3\u7801\u6709\u4ec0\u4e48\u95ee\u9898\uff1f<\/p>\n
bool func(size_t cbSize) {\n if (cbSize < 1024) {\n \/\/ we never deal with a string trailing null\n char *buf = new char[cbSize-1];\n memset(buf,0,cbSize-1);\n\n \/\/ do stuff\n\n delete [] buf;\n\n return true;\n } else {\n return false;\n }\n}\n<\/pre>\n\u4ee3\u7801\u662f\u6b63\u786e\u7684\uff0c\u5bf9\u5417\uff1f\u5b83\u9a8c\u8bc1 cbSize \u4e0d\u5927\u4e8e 1 KB\uff0c\u5e76\u4e14 new \u6216 malloc \u5e94\u8be5\u59cb\u7ec8\u6b63\u786e\u5730\u5206\u914d 1 KB\uff0c\u5bf9\u5417\uff1f\u8ba9\u6211\u4eec\u5ffd\u7565\u4ee5\u4e0b\u4e8b\u5b9e\uff0cnew \u6216 malloc \u7684\u8fd4\u56de\u503c\u5e94\u8be5\u5728\u6b64\u65f6\u8fdb\u884c\u68c0\u67e5\u3002\u540c\u6837\uff0ccbSize \u4e0d\u80fd\u4e3a\u8d1f\u6570\uff0c\u56e0\u4e3a\u5b83\u662f size_t\u3002\u4f46\u662f\uff0c\u5982\u679c cbSize \u662f\u96f6\uff0c\u53c8\u4f1a\u5982\u4f55\u5462\uff1f\u67e5\u770b\u4e00\u4e0b\u5206\u914d\u7f13\u51b2\u533a\u7684\u4ee3\u7801\uff0c\u5b83\u4ece\u7f13\u51b2\u533a\u5927\u5c0f\u8bf7\u6c42\u4e2d\u51cf\u53bb\u4e00\u3002\u4ece\u96f6\u51cf\u53bb\u4e00\u4f1a\u4ea7\u751f size_t \u53d8\u91cf\uff0c\u8fd9\u662f\u4e00\u4e2a\u65e0\u7b26\u53f7\u7684\u6574\u6570\uff0c\u5176\u9650\u5236\u4e3a 0xFFFFFFFF\uff08\u5047\u8bbe\u4e3a 32 \u4f4d\u7684\u503c\uff09\u6216\u8005 4 GB\u3002\u60a8\u7684\u5e94\u7528\u7a0b\u5e8f\u53ea\u6709\u7ed3\u675f\u4e86\uff0c\u6216\u8005\u66f4\u7cdf\uff01<\/p>\n
\u8bf7\u770b\u4e0b\u9762\u76f8\u4f3c\u7684\u95ee\u9898\uff1a<\/p>\n
bool func(char *s1, size_t len1,\n char *s2, size_t len2) {\n if (1 + len1 + len2 > 64)\n return false;\n\n \/\/ accommodate for the trailing null in the addition\n char *buf = (char*)malloc(len1+len2+1);\n if (buf) {\n StringCchCopy(buf,len1+len2,s1);\n StringCchCat(buf,len1+len2,s2);\n }\n\n \/\/ do other stuff with buf\n\n if (buf) free(buf);\n\n return true;\n}\n<\/pre>\n\u540c\u6837\uff0c\u4ee3\u7801\u770b\u8d77\u6765\u7f16\u5199\u5f97\u5f88\u597d\uff1b\u5b83\u68c0\u67e5\u6570\u636e\u5927\u5c0f\uff0c\u9a8c\u8bc1 malloc \u662f\u5426\u6210\u529f\uff0c\u5e76\u4e14\u4f7f\u7528 safe<\/i> \u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570 StringCchCopy \u548c StringCchCat\uff08\u60a8\u53ef\u4ee5\u4ece http:\/\/msdn.microsoft.com\/library\/en-us\/dnsecure\/html\/strsafe.asp<\/a> \u9605\u8bfb\u66f4\u591a\u5173\u4e8e\u8fd9\u4e9b\u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\u7684\u5185\u5bb9\uff09\u3002\u4f46\u662f\uff0c\u8fd9\u6bb5\u4ee3\u7801\u53ef\u80fd\u4f1a\u53d7\u5230\u6574\u6570\u4e0a\u6ea2\u7684\u5371\u5bb3\u3002\u5982\u679c len1 \u662f 64\uff0clen2 \u662f 0xFFFFFFFF\uff0c\u53c8\u4f1a\u5982\u4f55\u5462\uff1f\u786e\u5b9a\u7f13\u51b2\u533a\u5927\u5c0f\u7684\u4ee3\u7801\u5408\u6cd5\u5730\u5c06 1\u300164 \u548c 0xFFFFFFFF \u52a0\u5728\u4e00\u8d77\uff0c\u7531\u4e8e\u52a0\u64cd\u4f5c\u7684\u9650\u5236\uff0c\u4f1a\u4ea7\u751f 64\u3002\u63a5\u4e0b\u6765\uff0c\u4ee3\u7801\u4ec5\u5206\u914d\u4e86 64 \u4e2a\u5b57\u8282\uff0c\u7136\u540e\u4ee3\u7801\u751f\u6210\u4e86\u4e00\u4e2a\u957f\u5ea6\u4e3a 64 \u4e2a\u5b57\u8282\u7684\u65b0\u5b57\u7b26\u4e32\uff0c\u7136\u540e\u5c06 0xFFFFFFFFF \u5b57\u8282\u4e0e\u8be5\u5b57\u7b26\u4e32\u76f8\u8fde\u3002\u540c\u6837\uff0c\u5e94\u7528\u7a0b\u5e8f\u5c06\u4f1a\u7ed3\u675f\uff0c\u5728\u67d0\u4e9b\u60c5\u51b5\u4e0b\uff0c\u5982\u679c\u5229\u7528\u7cbe\u5fc3\u8bbe\u8ba1\u7684\u5927\u5c0f\u8fdb\u884c\u653b\u51fb\uff0c\u4ee3\u7801\u53ef\u80fd\u4f1a\u53d7\u5230\u53ef\u7528\u7f13\u51b2\u533a\u6ea2\u51fa\u653b\u51fb\u3002<\/p>\n
\u6b64\u5904\u7684\u53e6\u5916\u4e00\u4e2a\u6559\u8bad\u5c31\u662f\uff0c\u5982\u679c\u7f13\u51b2\u533a\u5927\u5c0f\u8ba1\u7b97\u4e0d\u6b63\u786e\uff0c_safe<\/i> \u5b57\u7b26\u4e32\u5904\u7406\u51fd\u6570\u5c31\u4e0d\u5b89\u5168\u3002<\/p>\n
![\"\"](\"http:\/\/msdn.microsoft.com\/zh-cn\/library\/ms972818.arrow_px_up(zh-cn,MSDN.10).gif\")
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\nJScript \u6ea2\u51fa\u653b\u51fb<\/h5>\n
\u5f53\u4f7f\u7528\u4e58\u6cd5\u65f6\u4e5f\u4f1a\u51fa\u73b0\u76f8\u540c\u7c7b\u578b\u7684\u4e0a\u6ea2\u9519\u8bef\uff0c\u8fd9\u53d1\u751f\u5728 Microsoft JScript \u9519\u8bef\u4e2d\u3002\u8be5\u9519\u8bef\u4ec5\u8868\u660e\u5b83\u81ea\u5df1\u5728\u4f7f\u7528 JScript \u7a00\u758f\u6570\u7ec4\u652f\u6301\u65f6\u4f1a\u51fa\u73b0\uff1a<\/p>\n
var arr = new Array();\narr[1] = 1;\narr[2] = 2;\narr[0x40000001] = 3;\n<\/pre>\n
\u5728\u8fd9\u4e2a\u793a\u4f8b\u4e2d\uff0c\u6570\u7ec4\u5177\u6709\u4e09\u4e2a\u5143\u7d20\uff0c\u4e14\u957f\u5ea6\u4e3a 0x40000001\uff08\u5341\u8fdb\u5236\u4e3a 1073741825\uff09\u3002\u4f46\u662f\uff0c\u7531\u4e8e\u8be5\u793a\u4f8b\u4f7f\u7528\u7a00\u758f\u6570\u7ec4\uff0c\u5b83\u53ea\u5360\u7528\u5185\u5b58\u7684\u4e09\u4e2a\u5143\u7d20\u7684\u6570\u7ec4\u3002<\/p>\n
\u5b9e\u73b0 JScript \u81ea\u5b9a\u4e49\u6392\u5e8f\u4f8b\u7a0b\u7684 C++ \u4ee3\u7801\u5728\u5806\u4e0a\u5206\u914d\u4e34\u65f6\u7684\u7f13\u51b2\u533a\u3001\u5c06\u4e09\u4e2a\u5143\u7d20\u590d\u5236\u5230\u4e34\u65f6\u7f13\u51b2\u533a\u4e2d\u3001\u4f7f\u7528\u81ea\u5b9a\u4e49\u51fd\u6570\u6392\u5e8f\u4e34\u65f6\u7f13\u51b2\u533a\uff0c\u7136\u540e\u5c06\u4e34\u65f6\u7f13\u51b2\u533a\u7684\u5185\u5bb9\u79fb\u52a8\u56de\u6570\u7ec4\u4e2d\u3002\u4e0b\u9762\u662f\u5206\u914d\u4e34\u65f6\u7f13\u51b2\u533a\u7684\u4ee3\u7801\uff1a<\/p>\n
TemporaryBuffer = (Element *)malloc(ElementCount * sizeof(Element));<\/p>\n
Element \u662f\u4e00\u4e2a 20 \u5b57\u8282\u7684\u6570\u636e\u7ed3\u6784\uff0c\u7528\u4e8e\u4fdd\u5b58\u6570\u7ec4\u9879\u3002\u770b\u8d77\u6765\u7a0b\u5e8f\u5c06\u5c1d\u8bd5\u4e3a\u4e34\u65f6\u7f13\u51b2\u533a\u5206\u914d\u5927\u7ea6 20 GB\u3002\u60a8\u53ef\u80fd\u8ba4\u4e3a\u7531\u4e8e\u5927\u591a\u6570\u4eba\u7684\u8ba1\u7b97\u673a\u4e0a\u4e0d\u4f1a\u6709 20 GB \u7684\u5185\u5b58\uff0c\u5206\u914d\u5c1d\u8bd5\u5c06\u4f1a\u5931\u8d25\u3002\u90a3\u4e48\uff0cJScript \u5e38\u89c4\u5185\u5b58\u4e0d\u8db3\u5904\u7406\u4f8b\u7a0b\u5c06\u4f1a\u5904\u7406\u8be5\u95ee\u9898\u3002\u9057\u61be\u7684\u662f\uff0c\u5e76\u6ca1\u6709\u53d1\u751f\u8fd9\u6837\u7684\u60c5\u51b5\u3002<\/p>\n
\u5f53\u4f7f\u7528 32 \u4f4d\u7684\u6574\u6570\u7b97\u6cd5\u65f6\uff0c\u7531\u4e8e\u7ed3\u679c (0x0000000500000014) \u592a\u5927\u65e0\u6cd5\u4fdd\u5b58\u5728 32 \u4f4d\u7684\u503c\u4e2d\uff0c\u6211\u4eec\u4f1a\u53d7\u5230\u4e00\u4e2a\u6574\u6570\u4e0a\u6ea2\u653b\u51fb\uff1a<\/p>\n
0x40000001 * 0x00000014 = 0x0000000500000014\n<\/pre>\n
C++ \u4f1a\u4e22\u5f03\u6240\u6709\u4e0d\u7b26\u5408\u7684\u4f4d\uff0c\u56e0\u6b64\u6211\u4eec\u4f1a\u5f97\u5230 0x00000014\u3002\u8fd9\u5c31\u662f\u5206\u914d\u5e76\u672a\u5931\u8d25\u7684\u539f\u56e0 \uff0d \u5206\u914d\u6ca1\u6709\u5c1d\u8bd5\u53bb\u5206\u914d 20 GB\uff0c\u800c\u662f\u4ec5\u4ec5\u5c1d\u8bd5\u5206\u914d\u4e86 20 \u4e2a\u5b57\u8282\u3002\u7136\u540e\uff0c\u6392\u5e8f\u4f8b\u7a0b\u4f1a\u5047\u8bbe\u7f13\u51b2\u533a\u5bf9\u4e8e\u4fdd\u5b58\u7a00\u758f\u6570\u7ec4\u4e2d\u7684\u4e09\u4e2a\u5143\u7d20\u6765\u8bf4\u8db3\u591f\u5927\uff0c\u56e0\u6b64\u5b83\u5c06\u7ec4\u6210\u8fd9\u4e09\u4e2a\u5143\u7d20\u7684 60 \u4e2a\u5b57\u8282\u590d\u5236\u5230\u4e86 20 \u4e2a\u5b57\u8282\u7684\u7f13\u51b2\u533a\u4e2d\uff0c\u8fd9\u6837\u5c31\u6ea2\u51fa\u7f13\u51b2\u533a 40 \u4e2a\u5b57\u8282\u3002\u5b9e\u5728\u592a\u5192\u9669\u4e86\uff01<\/p>\n
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u6709\u7b26\u53f7\u4e0e\u65e0\u7b26\u53f7\u9519\u8bef<\/h5>\n
\u5feb\u901f\u67e5\u770b\u4e0b\u9762\u7684\u4ee3\u7801\u3002\u5b83\u7c7b\u4f3c\u4e8e\u7b2c\u4e00\u4e2a\u793a\u4f8b\u3002\u770b\u770b\u60a8\u662f\u5426\u80fd\u591f\u53d1\u73b0\u9519\u8bef\uff0c\u5982\u679c\u60a8\u53d1\u73b0\u4e86\u9519\u8bef\uff0c\u8bf7\u8bd5\u7740\u786e\u5b9a\u8be5\u9519\u8bef\u4f1a\u4ea7\u751f\u4ec0\u4e48\u7ed3\u679c\u3002<\/p>\n
bool func(char *s1, int len1,\n char *s2, int len2) {\n\n char buf[128];\n\n if (1 + len1 + len2 > 128)\n return false;\n\n if (buf) {\n strncpy(buf,s1,len1);\n strncat(buf,s2,len2);\n }\n\n return true;\n}\n<\/pre>\n\u6b64\u5904\u7684\u95ee\u9898\u5728\u4e8e\u5b57\u7b26\u4e32\u7684\u5927\u5c0f\u5b58\u50a8\u4e3a\u6709\u7b26\u53f7\u7684\u6574\u6570\uff0c\u56e0\u6b64\u53ea\u8981 len2 \u662f\u8d1f\u503c\uff0clen1 \u5c31\u53ef\u4ee5\u5927\u4e8e 128\uff0c\u4ece\u800c\u548c\u5c31\u5c0f\u4e8e 128 \u4e2a\u5b57\u8282\u3002\u4f46\u662f\uff0c\u5230 strncpy \u7684\u8c03\u7528\u5c06\u4f1a\u6ea2\u51fa buf \u7f13\u51b2\u533a\u3002<\/p>\n
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u622a\u65ad\u9519\u8bef<\/h5>\n
\u8ba9\u6211\u4eec\u67e5\u770b\u6700\u540e\u4e00\u79cd\u653b\u51fb\u7c7b\u578b\uff0c\u901a\u8fc7\u4ee3\u7801\u793a\u4f8b\uff0c\u60a8\u6765\u731c\u731c\u770b\u3002 <\/p>\n
bool func(byte *name, DWORD cbBuf) {\n unsigned short cbCalculatedBufSize = cbBuf;\n byte *buf = (byte*)malloc(cbCalculatedBufSize);\n if (buf) {\n memcpy(buf, name, cbBuf);\n \/\/ do stuff with buf\n if (buf) free(buf);\n return true;\n }\n\n return false;\n}\n<\/pre>\n\u8fd9\u79cd\u653b\u51fb\uff0c\u81f3\u5c11\u8fd9\u79cd\u7ed3\u679c\uff0c\u4e0e\u524d\u9762\u9610\u8ff0\u7684 JScript \u9519\u8bef\u6709\u4e00\u70b9\u7c7b\u4f3c\u3002\u5982\u679c cbBuf \u662f 0x00010020\uff0c\u53c8\u4f1a\u5982\u4f55\u5462\uff1fcbCalculatedBufSize \u53ea\u6709 0x20\uff0c\u56e0\u4e3a\u53ea\u4ece 0x00010020 \u590d\u5236\u4e86\u4f4e 16 \u4f4d\u3002\u56e0\u6b64\uff0c\u4ec5\u5206\u914d\u4e86 0x20 \u4e2a\u5b57\u8282\uff0c\u5e76\u4e14 0x00010020 \u5b57\u8282\u590d\u5236\u5230\u65b0\u5206\u914d\u7684\u76ee\u6807\u7f13\u51b2\u533a\u4e2d\u3002\u8bf7\u6ce8\u610f\uff0c\u4f7f\u7528 Microsoft Visual C++?\/W4 \u9009\u9879\u7f16\u8bd1\u8fd9\u6bb5\u4ee3\u7801\u4f1a\u751f\u6210\uff1a<\/p>\n
warning C4244: 'initializing' : conversion from 'DWORD' to 'unsigned\nshort', possible loss of data\n<\/pre>\n
\u8bf7\u6ce8\u610f\u7c7b\u4f3c\u4e0b\u9762\u7684\u64cd\u4f5c\u4e0d\u8981\u6807\u8bb0\u4e3a\u4e00\u4e2a\u8b66\u544a\uff1a<\/p>\n
int len = 16;\nmemcpy(buf, szData, len);\n<\/pre>\n
memcpy \u7684\u6700\u540e\u4e00\u4e2a\u53c2\u6570\u662f size_t\uff0c\u800c\u53c2\u6570 len \u662f\u6709\u7b26\u53f7\u7684\u3002\u4e0d\u4f1a\u53d1\u51fa\u8b66\u544a\u662f\u56e0\u4e3a memcpy \u59cb\u7ec8\u5047\u8bbe\u7b2c\u4e09\u4e2a\u53c2\u6570\u662f\u65e0\u7b26\u53f7\u7684\uff0c\u8f6c\u6362\u6210\u65e0\u7b26\u53f7\u4e0d\u4f1a\u6539\u53d8\u51fd\u6570\u7684\u8f93\u51fa\u3002<\/p>\n
\u6ce8\u610f\uff0c\u5982\u679c\u60a8\u5c1d\u8bd5\u4e3a DWORD \u5206\u914d\u4e00\u4e2a size_t\uff0c\u60a8\u5c06\u4f1a\u6536\u5230\u4e00\u4e2a\u8b66\u544a\uff0c\u5e76\u4e0d\u662f\u56e0\u4e3a\u5728 32 \u4f4d\u5e73\u53f0\u4e0a\u53ef\u80fd\u4f1a\u51fa\u73b0\u6570\u636e\u4e22\u5931\uff0c\u800c\u662f\u56e0\u4e3a\u5728 64 \u4f4d\u5e73\u53f0\u4e0a\u5c06\u4f1a\u51fa\u73b0\u6570\u636e\u4e22\u5931\u3002<\/p>\n
warning C4267: '=' : conversion from 'size_t' to 'DWORD', possible loss\nof data\n<\/pre>\n
\u60a8\u5c06\u6536\u5230\u8fd9\u4e2a\u8b66\u544a\uff0c\u56e0\u4e3a\u6240\u6709\u9ed8\u8ba4 C++ \u9879\u76ee\u90fd\u4f7f\u7528 -Wp64 \u9009\u9879\u8fdb\u884c\u7f16\u8bd1\uff0c\u8be5\u9009\u9879\u4f1a\u901a\u77e5\u7f16\u8bd1\u5668\u76d1\u89c6 64 \u4f4d\u53ef\u79fb\u690d\u6027\u95ee\u9898\u3002<\/p>\n
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u6258\u7ba1\u4ee3\u7801\u4e2d\u7684\u6574\u6570\u64cd\u4f5c\u95ee\u9898<\/h5>\n
\u6574\u6570\u64cd\u4f5c\u9519\u8bef\u53ef\u80fd\u4f1a\u53d1\u751f\u5728\u6258\u7ba1\u8bed\u8a00\u4e2d\uff0c\u4f8b\u5982 C# \u548c Visual Basic?.NET\uff0c\u4f46\u662f\u6f5c\u5728\u7684\u635f\u5bb3\u4f1a\u7531\u4e8e\u4ee3\u7801\u4e0d\u76f4\u63a5\u8bbf\u95ee\u5185\u5b58\u800c\u663e\u8457\u5730\u964d\u4f4e\u3002\u4f46\u662f\uff0c\u8c03\u7528\u672c\u673a\u4ee3\u7801\uff08\u5047\u8bbe\u60a8\u7684\u4ee3\u7801\u88ab\u6388\u4e88\u8c03\u7528\u975e\u6258\u7ba1\u4ee3\u7801\u7684\u6743\u9650\uff09\u4ecd\u7136\u53ef\u80fd\u4f1a\u5f15\u8d77\u7c7b\u4f3c\u4e8e\u4e0a\u8ff0\u7684\u5b89\u5168\u6027\u95ee\u9898\u3002\u901a\u7528\u8bed\u8a00\u89c4\u8303 (CLS) \u4e2d\u7684\u6574\u6570\u662f\u6709\u7b26\u53f7\u7684\uff0c\u4e00\u4e2a\u9519\u8bef\u5c31\u662f\u5f53\u5728\u975e\u6258\u7ba1\u4ee3\u7801\u4e2d\u5c06\u53d8\u91cf\u89c6\u4e3a\u65e0\u7b26\u53f7\u7684\u6574\u6570\u65f6\uff0c\u5728\u6258\u7ba1\u4ee3\u7801\u4e2d\u9a8c\u8bc1\u662f\u5426\u4e3a\u6709\u7b26\u53f7\u7684\u6574\u6570\u53c2\u6570\u3002<\/p>\n
\u8fd9\u4e2a\u7279\u5b9a\u7684\u4f8b\u5b50\u63d0\u51fa\u4e86\u4e00\u4e2a\u66f4\u901a\u7528\u7684\u5efa\u8bae\uff1a\u59cb\u7ec8\u68c0\u67e5\u8981\u4f20\u9012\u5230\u672a\u6258\u7ba1\u4ee3\u7801\u7684\u5185\u5bb9\u3002\u6258\u7ba1\u4ee3\u7801\u4e2d\u7684\u5f88\u591a\u6574\u6570\u64cd\u4f5c\u9519\u8bef\u53ef\u80fd\u4f1a\u5f15\u8d77 Visual Basic .NET \u4e2d\u7684\u53ef\u9760\u6027\u9519\u8bef\uff0c\u56e0\u4e3a\u5982\u679c\u53d1\u751f\u4e0a\u6ea2\u6216\u4e0b\u6ea2\uff0c\u6240\u6709\u8fd9\u6837\u7684\u64cd\u4f5c\u90fd\u5c06\u5f15\u53d1 System.OverflowException\u3002<\/p>\n
\u9ed8\u8ba4\u60c5\u51b5\u4e0b\uff0cC# \u5e76\u4e0d\u5f15\u53d1\u8fd9\u4e9b\u5f02\u5e38\u3002\u5982\u679c\u60a8\u5e0c\u671b\u68c0\u67e5\u8fd9\u4e9b\u95ee\u9898\uff0c\u8bf7\u4f7f\u7528 checked \u5173\u952e\u5b57\uff1a<\/p>\n
UInt32 i = 0xFFFFFFF0;\nUInt32 j = 0x00000100;\nUInt32 k;\nchecked {k = i + j;}\n<\/pre>\n <\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u8865\u6551\u63aa\u65bd<\/h5>\n
\u8c01\u4f1a\u60f3\u5230\u53ea\u662f\u64cd\u4f5c\u6574\u6570\u5c31\u4f1a\u5bfc\u81f4\u5b89\u5168\u6027\u95ee\u9898\u5462\uff1f\u5bf9\u4e8e\u6613\u53d7\u653b\u51fb\u7684\u4ee3\u7801\u7684\u7b80\u5355\u7684\u8865\u6551\u63aa\u65bd\u5982\u4e0b\u6240\u793a\uff1a<\/p>\n
if (A + B > MAX) return -1;\n<\/pre>\n
\u5229\u7528\u65e0\u7b26\u53f7\u6574\u6570\u4f7f\u7528\u8be5\u4ee3\u7801\uff1a<\/p>\n
if (A + B >= A && A + B < MAX) {\n \/\/ cool!\n}\n<\/pre>\n\u7b2c\u4e00\u4e2a\u64cd\u4f5c A + B >= A\uff0c\u68c0\u67e5\u662f\u5426\u5b58\u5728\u5305\u56f4\uff0c\u7b2c\u4e8c\u4e2a\u64cd\u4f5c\u786e\u4fdd\u76f8\u52a0\u540e\u7684\u548c\u5c0f\u4e8e\u76ee\u6807\u5927\u5c0f\u3002<\/p>\n
\u5bf9\u4e8e JScript \u4e2d\u7684\u64cd\u4f5c\u95ee\u9898\uff0c\u60a8\u53ef\u4ee5\u68c0\u67e5\u5143\u7d20\u7684\u6570\u91cf\u4e0d\u8d85\u8fc7\u9884\u5b9a\u7684\u503c\uff0c\u800c\u9884\u5b9a\u7684\u503c\u8981\u5c0f\u4e8e\u60a8\u5c06\u8981\u5206\u914d\u7ed9\u5185\u5b58\u7684\u6700\u5927\u91cf\u3002\u4f8b\u5982\uff0c\u4e0b\u9762\u7684\u4ee3\u7801\u4f1a\u6f5c\u5728\u5730\u5206\u914d\u591a\u8fbe 64 MB \u7684\u5185\u5b58\uff1a<\/p>\n
const size_t MAX = 1024 * 1024 * 64;\nconst size_t ELEM_SIZE = sizeof(ELEMENT);\nconst size_t MAX_ELEMS = MAX \/ ELEM_SIZE;\n\nif (cElems >= MAX_ELEMS)\n return false;\n<\/pre>\n
\u6700\u540e\uff0c\u5bf9\u4e8e\u6570\u7ec4\u7d22\u5f15\u3001\u7f13\u51b2\u533a\u5927\u5c0f\u4ee5\u53ca\u76f8\u4f3c\u5bf9\u8c61\uff0c\u8bf7\u4f7f\u7528\u65e0\u7b26\u53f7\u7684\u6574\u6570\uff0c\u4f8b\u5982 DWORD \u548c size_t\u3002<\/p>\n
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u5173\u952e\u4ee3\u7801\u68c0\u67e5\u70b9<\/h5>\n
\u5f53\u7f16\u8bd1\u6216\u68c0\u67e5\u4e0e\u6574\u6570\u76f8\u5173\u7684\u95ee\u9898\u7684\u4ee3\u7801\u65f6\uff0c\u8bf7\u8bb0\u4f4f\u4e0b\u5217\u8981\u70b9\uff1a<\/p>\n
- \n
- \n
\u4f7f\u7528\u6700\u9ad8\u7684\u8b66\u544a\u7ea7\u522b \/W4 \u6765\u7f16\u8bd1 C \u548c C++ \u4ee3\u7801\u3002 <\/p>\n
- \n
\u5bf9\u4e8e\u7f13\u51b2\u533a\u5927\u5c0f\u548c\u5143\u7d20\u8ba1\u6570\uff0c\u4f7f\u7528 size_t \u6216 DWORD\u3002\u6ca1\u6709\u4efb\u4f55\u7406\u7531\u8981\u4e3a\u8fd9\u4e9b\u7ed3\u6784\u4f7f\u7528\u6709\u7b26\u53f7\u7684\u503c\u3002 <\/p>\n
- \n
\u8bf7\u7262\u8bb0\uff0csize_t \u4f1a\u6839\u636e\u60a8\u6240\u4f7f\u7528\u7684\u5e73\u53f0\u6765\u8868\u793a\u4e0d\u540c\u7684\u7c7b\u578b\u3002size_t \u662f\u5185\u5b58\u5730\u5740\u7684\u5927\u5c0f\uff0c\u56e0\u6b64\u5728 32 \u4f4d\u5e73\u53f0\u4e0a\uff0c\u5b83\u662f 32 \u4f4d\u7684\u503c\uff0c\u4f46\u5728 64 \u4f4d\u5e73\u53f0\u4e0a\uff0c\u5b83\u5c31\u662f 64 \u4f4d\u7684\u503c\u3002 <\/p>\n
- \n
\u5982\u679c\u4ee3\u7801\u6267\u884c\u4efb\u610f\u7c7b\u578b\u7684\u6574\u6570\u64cd\u4f5c\uff08\u52a0\u3001\u4e58\u7b49\u7b49\uff09\uff0c\u5176\u4e2d\u7ed3\u679c\u7528\u4e8e\u7d22\u5f15\u5230\u6570\u7ec4\u6216\u8ba1\u7b97\u7f13\u51b2\u533a\u5927\u5c0f\uff0c\u8bf7\u786e\u4fdd\u64cd\u4f5c\u6570\u4f4d\u4e8e\u4e00\u4e2a\u5c0f\u7684\u3001\u5bb9\u6613\u7406\u89e3\u7684\u8303\u56f4\u5185\u3002 <\/p>\n
- \n
\u8b66\u60d5\u5185\u5b58\u5206\u914d\u51fd\u6570\uff08new<\/b>\u3001malloc<\/b>\u3001GlobalAlloc<\/b> \u7b49\u7b49\uff09\u7684\u6709\u7b26\u53f7\u53c2\u6570\uff0c\u56e0\u4e3a\u5b83\u4eec\u5c06\u88ab\u89c6\u4e3a\u65e0\u7b26\u53f7\u7684\u6574\u6570\u3002 <\/p>\n
- \n
\u6ce8\u610f\u4ea7\u751f C4018\u3001C4389 \u548c C4244 \u8b66\u544a\u7684\u64cd\u4f5c\u3002 <\/p>\n
- \n
\u6ce8\u610f\u629b\u5f03 C4018\u3001C4389 \u548c C4244 \u8b66\u544a\u7684\u8f6c\u6362\u3002 <\/p>\n
- \n
\u8c03\u67e5\u7981\u7528 C4018\u3001C4389 \u548c C4244 \u8b66\u544a\u7684 #pragma warning(disable, Cnnnn) \u7684\u6240\u6709\u4f7f\u7528\u3002\u5b9e\u9645\u4e0a\uff0c\u5c06\u5b83\u4eec\u6807\u8bb0\u4e3a\u6ce8\u91ca\u3001\u91cd\u65b0\u7f16\u8bd1\uff0c\u7136\u540e\u68c0\u67e5\u4e0e\u6574\u6570\u76f8\u5173\u7684\u6240\u6709\u65b0\u7684\u8b66\u544a\u3002 <\/p>\n
- \n
\u4ece\u5176\u4ed6\u5e73\u53f0\u6216\u7f16\u8bd1\u5668\u8fc1\u79fb\u7684\u4ee3\u7801\u53ef\u80fd\u4f1a\u4f7f\u7528\u4e0d\u540c\u7684\u6570\u636e\u5927\u5c0f\u3002\u5343\u4e07\u8981\u5c0f\u5fc3\uff01 <\/p>\n
- \n
\u5982\u679c\u4ece\u6258\u7ba1\u4ee3\u7801\u8c03\u7528\u975e\u6258\u7ba1\u4ee3\u7801\uff0c\u8bf7\u786e\u4fdd\u5b83\u7684\u7b26\u53f7\u662f\u6b63\u786e\u7684\u3002Win32 API \u7684\u5f88\u591a\u53c2\u6570\u90fd\u662f\u65e0\u7b26\u53f7\u7684 int \u6216 DWORD\uff0c\u800c\u5f88\u591a\u6258\u7ba1\u4ee3\u7801\u53d8\u91cf\u5219\u662f\u6709\u7b26\u53f7\u7684\u3002 <\/p>\n
- \n
\u6700\u540e\uff0c\u5982\u679c\u60a8\u4f7f\u7528\u6258\u7ba1\u4ee3\u7801\uff0c\u8bf7\u786e\u4fdd\u5728\u9002\u5f53\u7684\u65f6\u5019\u4f7f\u7528 catch OverflowExceptions<\/b>\u3002 <\/p>\n<\/li>\n<\/ul>\n
<\/a>\u8fd4\u56de\u9875\u9996<\/a><\/p>\n\u53d1\u73b0\u5b89\u5168\u6f0f\u6d1e<\/h5>\n
\u5f88\u591a\u4eba\u68c0\u67e5\u51fa\u4e86\u6211\u4e0a\u4e2a\u6708\u7684\u95ee\u9898\u3002\u5b83\u662f\u4e00\u4e2a\u6574\u6570\u4e0a\u6ea2\u653b\u51fb\u3002\u90a3\u4e48\u8fd9\u6bb5 C# \u4ee3\u7801\u6709\u4ec0\u4e48\u95ee\u9898\u5462\uff1f<\/p>\n
string Status = \"No\";\nstring sqlstring =\"\";\ntry {\n SqlConnection sql= new SqlConnection(\n @\"data source=localhost;\" +\n \"user id=sa;password=password;\");\n sql.Open();\n sqlstring=\"SELECT HasShipped\" +\n \" FROM detail WHERE ID='\" + Id + \"'\";\n SqlCommand cmd = new SqlCommand(sqlstring,sql);\n if ((int)cmd.ExecuteScalar() != 0)\n Status = \"Yes\";\n} catch (SqlException se) {\n Status = sqlstring + \" failednr\";\n foreach (SqlError e in se.Errors) {\n Status += e.Message + \"nr\";\n }\n} catch (Exception e) {\n Status = e.ToString();\n}\n<\/pre>\n<\/blockquote>\n\u68c0\u67e5\u4ee3\u7801\u662f\u5426\u5b58\u5728\u6574\u6570\u64cd\u4f5c\u5b89\u5168\u6f0f\u6d1e<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"
\u68c0\u67e5\u4ee3\u7801\u662f\u5426\u5b58\u5728\u6574\u6570\u64cd\u4f5c\u5b89\u5168\u6f0f\u6d1e \u53d1\u5e03\u65e5\u671f : 09\/02\/2004 | \u66f4\u65b0\u65e5\u671f : 09\/0 … \u7ee7\u7eed\u9605\u8bfb\u201c\u68c0\u67e5\u4ee3\u7801\u662f\u5426\u5b58\u5728\u6574\u6570\u64cd\u4f5c\u5b89\u5168\u6f0f\u6d1e\u201d<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[137,166,244,358,460],"class_list":["post-7822","post","type-post","status-publish","format-standard","hentry","category-uncategorized","tag-dword","tag-gb","tag-max","tag-sql-2","tag-460"],"_links":{"self":[{"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/posts\/7822","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/comments?post=7822"}],"version-history":[{"count":0,"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/posts\/7822\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/media?parent=7822"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/categories?post=7822"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.bohu.net\/blog\/wp-json\/wp\/v2\/tags?post=7822"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
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