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Overview
| Comment: | Update the HTTP server to prohibit malformed and possibly malicious HTTP_HOST parameters. |
|---|---|
| Timelines: | family | ancestors | descendants | both | trunk |
| Files: | files | file ages | folders |
| SHA1: |
5bb4dfcc73b900a9f9544333b604dcee |
| User & Date: | drh 2014-10-05 20:54:57 |
Context
|
2014-10-05
| ||
| 23:01 | Improved documentation comments on the althttpd.c server program. check-in: d217041b2b user: drh tags: trunk | |
| 20:54 | Update the HTTP server to prohibit malformed and possibly malicious HTTP_HOST parameters. check-in: 5bb4dfcc73 user: drh tags: trunk | |
| 20:07 | Move the 3.8.7 release into October. Updates to URI documentation. check-in: 55869edbde user: drh tags: trunk | |
Changes
Changes to misc/althttpd.c.
888 888 /* 1x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 889 889 /* 2x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 1, 1, 890 890 /* 3x */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 891 891 /* 4x */ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 892 892 /* 5x */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1, 893 893 /* 6x */ 0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 894 894 /* 7x */ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 0, 895 +/* 8x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 896 +/* 9x */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 897 +/* Ax */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 898 +/* Bx */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 899 +/* Cx */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 900 +/* Dx */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 901 +/* Ex */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 902 +/* Fx */ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 895 903 }; 904 + 905 +/* 906 +** Remove all disallowed characters in the input string z[]. Convert any 907 +** disallowed characters into "_". 908 +** 909 +** Not that the three character sequence "%XX" where X is any byte is 910 +** converted into a single "_" character. 911 +** 912 +** Return the number of characters converted. An "%XX" -> "_" conversion 913 +** counts as a single character. 914 +*/ 915 +static int sanitizeString(char *z){ 916 + int nChange = 0; 917 + while( *z ){ 918 + if( !allowedInName[*(unsigned char*)z] ){ 919 + if( *z=='%' && z[1]!=0 && z[2]!=0 ){ 920 + int i; 921 + for(i=3; (z[i-2] = z[i])!=0; i++){} 922 + } 923 + *z = '_'; 924 + nChange++; 925 + } 926 + z++; 927 + } 928 + return nChange; 929 +} 896 930 897 931 /* 898 932 ** Count the number of "/" characters in a string. 899 933 */ 900 934 static int countSlashes(const char *z){ 901 935 int n = 0; 902 936 while( *z ) if( *(z++)=='/' ) n++; ................................................................................ 1015 1049 closeConnection = 1; 1016 1050 }else if( !forceClose && strcasecmp(zVal, "keep-alive")==0 ){ 1017 1051 closeConnection = 0; 1018 1052 } 1019 1053 }else if( strcasecmp(zFieldName,"Host:")==0 ){ 1020 1054 int inSquare = 0; 1021 1055 char c; 1056 + if( sanitizeString(zVal) ) Forbidden(); 1022 1057 zHttpHost = StrDup(zVal); 1023 1058 zServerPort = zServerName = StrDup(zHttpHost); 1024 1059 while( zServerPort && (c = *zServerPort)!=0 1025 1060 && (c!=':' || inSquare) ){ 1026 1061 if( c=='[' ) inSquare = 1; 1027 1062 if( c==']' ) inSquare = 0; 1028 1063 zServerPort++; ................................................................................ 1035 1070 zServerPort = StrDup(zRealPort); 1036 1071 } 1037 1072 }else if( strcasecmp(zFieldName,"Authorization:")==0 ){ 1038 1073 zAuthType = GetFirstElement(StrDup(zVal), &zAuthArg); 1039 1074 } 1040 1075 } 1041 1076 1042 - /* Disallow referring from certain clients */ 1077 + /* Disallow requests from certain clients */ 1043 1078 if( zAgent ){ 1044 1079 if( strstr(zAgent, "Windows_9")!=0 1045 1080 || strstr(zAgent, "Download_Master")!=0 1046 1081 || strstr(zAgent, "Ezooms/")!=0 1047 1082 /*|| strstr(zAgent, "bingbot")!=0*/ 1048 1083 || strstr(zAgent, "AhrefsBot")!=0 1049 1084 ){ ................................................................................ 1135 1170 /* Make sure the running time is not too great */ 1136 1171 if( useTimeout ) alarm(10); 1137 1172 1138 1173 /* Convert all unusual characters in the script name into "_". 1139 1174 ** 1140 1175 ** This is a defense against various attacks, XSS attacks in particular. 1141 1176 */ 1142 - for(z=zScript; *z; z++){ 1143 - unsigned char c = *(unsigned char*)z; 1144 - if( (c&0x80)!=0 || !allowedInName[c] ){ 1145 - *z = '_'; 1146 - if( c=='%' && z[1]!=0 && z[2]!=0 ){ 1147 - for(i=3; (z[i-2] = z[i])!=0; i++){} 1148 - } 1149 - } 1150 - } 1177 + sanitizeString(zScript); 1151 1178 1152 - /* Don't allow "/." or "/-" to to occur anywhere in the entity name. 1179 + /* Do not allow "/." or "/-" to to occur anywhere in the entity name. 1153 1180 ** This prevents attacks involving ".." and also allows us to create 1154 - ** files and directories whose names begin with "-" which are invisible 1155 - ** to the webserver. 1181 + ** files and directories whose names begin with "-" or "." which are 1182 + ** invisible to the webserver. 1156 1183 */ 1157 1184 for(z=zScript; *z; z++){ 1158 1185 if( *z=='/' && (z[1]=='.' || z[1]=='-') ){ 1159 1186 NotFound(__LINE__); 1160 1187 } 1161 1188 } 1162 1189