/* Licensed to the Apache Software Foundation (ASF) under one or more * contributor license agreements. See the NOTICE file distributed with * this work for additional information regarding copyright ownership. * The ASF licenses this file to You under the Apache License, Version 2.0 * (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License.
*/
/* A bunch of functions in util.c scan strings looking for certain characters. * To make that more efficient we encode a lookup table.
*/ #define T_ESCAPE_SHELL_CMD (0x01) #define T_ESCAPE_PATH_SEGMENT (0x02) #define T_OS_ESCAPE_PATH (0x04) #define T_HTTP_TOKEN_STOP (0x08) #define T_ESCAPE_LOGITEM (0x10) #define T_ESCAPE_FORENSIC (0x20) #define T_ESCAPE_URLENCODED (0x40) #define T_HTTP_CTRLS (0x80) #define T_VCHAR_OBSTEXT (0x100) #define T_URI_UNRESERVED (0x200)
int main(int argc, char *argv[])
{ unsigned c; unsignedshort flags;
for (c = 0; c < 256; ++c) {
flags = 0; if (c % 8 == 0)
printf("\n ");
/* escape_shell_cmd */ #ifdef NEED_ENHANCED_ESCAPES /* Win32/OS2 have many of the same vulnerable characters * as Unix sh, plus the carriage return and percent char. * The proper escaping of these characters varies from unix * since Win32/OS2 use carets or doubled-double quotes, * and neither lf nor cr can be escaped. We escape unix * specific as well, to assure that cross-compiled unix * applications behave similarly when invoked on win32/os2. * * Rem please keep in-sync with apr's list in win32/filesys.c
*/ if (c && strchr("&;`'\"|*?~<>^()[]{}$\\\n\r%", c)) {
flags |= T_ESCAPE_SHELL_CMD;
} #else if (c && strchr("&;`'\"|*?~<>^()[]{}$\\\n", c)) {
flags |= T_ESCAPE_SHELL_CMD;
} #endif
if (!apr_isalnum(c) && !strchr("$-_.+!*'(),:@&=~", c)) {
flags |= T_ESCAPE_PATH_SEGMENT;
}
if (!apr_isalnum(c) && !strchr("$-_.+!*'(),:;@&=/~", c)) {
flags |= T_OS_ESCAPE_PATH;
}
/* Stop for any non-'token' character, including ctrls, obs-text, * and "tspecials" (RFC2068) a.k.a. "separators" (RFC2616), which * is easier to express as characters remaining in the ASCII token set
*/ if (!c || !(apr_isalnum(c) || strchr("!#$%&'*+-.^_`|~", c))) {
flags |= T_HTTP_TOKEN_STOP;
}
/* Catch CTRLs other than VCHAR, HT and SP, and obs-text (RFC7230 3.2) * This includes only the C0 plane, not C1 (which is obs-text itself.) * XXX: We should verify that all ASCII C0 ctrls/DEL corresponding to * the current EBCDIC translation are captured, and ASCII C1 ctrls * corresponding are all permitted (as they fall under obs-text rule)
*/ if (!c || (apr_iscntrl(c) && c != '\t')) {
flags |= T_HTTP_CTRLS;
}
/* From RFC3986, the specific sets of gen-delims, sub-delims (2.2), * and unreserved (2.3) that are possible somewhere within a URI. * Spec requires all others to be %XX encoded, including obs-text.
*/ if (c && !apr_iscntrl(c) && c != ' ') {
flags |= T_VCHAR_OBSTEXT;
}
/* For logging, escape all control characters, * double quotes (because they delimit the request in the log file) * backslashes (because we use backslash for escaping) * and 8-bit chars with the high bit set
*/ if (c && (!apr_isprint(c) || c == '"' || c == '\\' || apr_iscntrl(c))) {
flags |= T_ESCAPE_LOGITEM;
}
/* For forensic logging, escape all control characters, top bit set, * :, | (used as delimiters) and % (used for escaping).
*/ if (!apr_isprint(c) || c == ':' || c == '|' || c == '%'
|| apr_iscntrl(c) || !c) {
flags |= T_ESCAPE_FORENSIC;
}
printf( "/* we assume the folks using this ensure 0 <= c < 256... which means\n" " * you need a cast to (unsigned char) first, you can't just plug a\n" " * char in here and get it to work, because if char is signed then it\n" " * will first be sign extended.\n" " */\n" "#define TEST_CHAR(c, f) (test_char_table[(unsigned char)(c)] & (f))\n"
);
return 0;
}
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