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ModSecurity/apache2/msc_util.c
brenosilva 549f059480 move 2.5.13 into trunk
2010-12-08 18:58:18 +00:00

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/*
* ModSecurity for Apache 2.x, http://www.modsecurity.org/
* Copyright (c) 2004-2010 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* This product is released under the terms of the General Public Licence,
* version 2 (GPLv2). Please refer to the file LICENSE (included with this
* distribution) which contains the complete text of the licence.
*
* There are special exceptions to the terms and conditions of the GPL
* as it is applied to this software. View the full text of the exception in
* file MODSECURITY_LICENSING_EXCEPTION in the directory of this software
* distribution.
*
* If any of the files related to licensing are missing or if you have any
* other questions related to licensing please contact Trustwave Holdings, Inc.
* directly using the email address support@trustwave.com.
*
*/
#include "modsecurity_config.h"
#include <ctype.h>
#include <fcntl.h>
#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include "msc_release.h"
#include "msc_util.h"
#include <apr_lib.h>
/**
* NOTE: Be careful as these can ONLY be used on static values for X.
* (i.e. VALID_HEX(c++) will NOT work)
*/
#define VALID_HEX(X) (((X >= '0')&&(X <= '9')) || ((X >= 'a')&&(X <= 'f')) || ((X >= 'A')&&(X <= 'F')))
#define ISODIGIT(X) ((X >= '0')&&(X <= '7'))
#if (defined(WIN32) || defined(NETWARE))
/** Windows does not define all the octal modes */
#define S_IXOTH 00001
#define S_IWOTH 00002
#define S_IROTH 00004
#define S_IXGRP 00010
#define S_IWGRP 00020
#define S_IRGRP 00040
#define S_IXUSR 00100
#define S_IWUSR 00200
#define S_IRUSR 00400
#define S_ISVTX 01000
#define S_ISGID 02000
#define S_ISUID 04000
#endif /* defined(WIN32 || NETWARE) */
/* Base64 tables used in decodeBase64Ext */
static const char b64_pad = '=';
static const short b64_reverse_t[256] = {
-2, -2, -2, -2, -2, -2, -2, -2, -2, -1, -1, -2, -2, -1, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-1, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, 62, -2, -2, -2, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -2, -2, -2, -2, -2, -2,
-2, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -2, -2, -2, -2, -2,
-2, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2,
-2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2, -2
};
/**
*
*/
int parse_boolean(const char *input) {
if (input == NULL) return -1;
if (strcasecmp(input, "on") == 0) return 1;
if (strcasecmp(input, "true") == 0) return 1;
if (strcasecmp(input, "1") == 0) return 1;
if (strcasecmp(input, "off") == 0) return 0;
if (strcasecmp(input, "false") == 0) return 0;
if (strcasecmp(input, "0") == 0) return 0;
return -1;
}
/* \brief Decode Base64 data with special chars
*
* \param plain_text Pointer to plain text data
* \param input Pointer to input data
* \param input_len Input data length
*
* \retval 0 On failure
* \retval string length On Success
*/
int decode_base64_ext(char *plain_text, const char *input, int input_len)
{
const char *encoded = input;
int i = 0, j = 0, k = 0;
int ch = 0;
while ((ch = *encoded++) != '\0' && input_len-- > 0) {
if (ch == b64_pad) {
if (*encoded != '=' && (i % 4) == 1) {
return 0;
}
continue;
}
ch = b64_reverse_t[ch];
if (ch < 0 || ch == -1) {
continue;
} else if (ch == -2) {
return 0;
}
switch(i % 4) {
case 0:
plain_text[j] = ch << 2;
break;
case 1:
plain_text[j++] |= ch >> 4;
plain_text[j] = (ch & 0x0f) << 4;
break;
case 2:
plain_text[j++] |= ch >>2;
plain_text[j] = (ch & 0x03) << 6;
break;
case 3:
plain_text[j++] |= ch;
break;
}
i++;
}
k = j;
if (ch == b64_pad) {
switch(i % 4) {
case 1:
return 0;
case 2:
k++;
case 3:
plain_text[k] = 0;
}
}
plain_text[j] = '\0';
return j;
}
/**
* Parses a string that contains a name-value pair in the form "name=value".
* IMP1 It does not check for whitespace between tokens.
*/
int parse_name_eq_value(apr_pool_t *mp, const char *input, char **name, char **value) {
char *p = NULL;
if ((name == NULL)||(value == NULL)) return -1;
if (input == NULL) return 0;
*name = NULL;
*value = NULL;
p = (char *)input;
while((*p != '=')&&(*p != '\0')) p++;
if (*p == '\0') {
*name = (char *)input;
return 1;
}
*name = apr_pstrmemdup(mp, input, p - input);
if (*name == NULL) return -1;
p++;
*value = apr_pstrdup(mp, p);
if (*value == NULL) return -1;
return 1;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
char *url_encode(apr_pool_t *mp, char *input, unsigned int input_len, int *changed) {
char *rval, *d;
unsigned int i, len;
*changed = 0;
len = input_len * 3 + 1;
d = rval = apr_palloc(mp, len);
if (rval == NULL) return NULL;
/* ENH Only encode the characters that really need to be encoded. */
for(i = 0; i < input_len; i++) {
unsigned char c = input[i];
if (c == ' ') {
*d++ = '+';
*changed = 1;
} else
if ( (c == 42) || ((c >= 48)&&(c <= 57)) || ((c >= 65)&&(c <= 90))
|| ((c >= 97)&&(c <= 122))
) {
*d++ = c;
} else {
*d++ = '%';
c2x(c, (unsigned char *)d);
d += 2;
*changed = 1;
}
}
*d = '\0';
return rval;
}
/**
* Appends an URL-encoded version of the source string to the
* destination string, but makes sure that no more than "maxlen"
* bytes are added.
*/
char *strnurlencat(char *destination, char *source, unsigned int maxlen) {
char *s = source;
char *d = destination;
/* ENH Only encode the characters that really need to be encoded. */
/* Advance to the end of destination string. */
while(*d != '\0') d++;
/* Loop while there's bytes in the source string or
* until we reach the output limit.
*/
while((*s != '\0')&&(maxlen > 0)) {
unsigned char c = *s;
if (c == ' ') {
*d++ = '+';
maxlen--;
} else
if ( (c == 42) || ((c >= 48)&&(c <= 57)) || ((c >= 65)&&(c <= 90))
|| ((c >= 97)&&(c <= 122))
) {
*d++ = c;
maxlen--;
} else {
if (maxlen >= 3) {
*d++ = '%';
c2x(c, (unsigned char *)d);
d += 2;
maxlen -= 3;
} else {
/* If there's not enough room for the encoded
* byte we ignore it.
*/
maxlen = 0;
}
}
s++;
}
*d++ = '\0';
return destination;
}
/**
*
*/
char *file_basename(apr_pool_t *mp, const char *filename) {
char *d, *p;
if (filename == NULL) return NULL;
d = apr_pstrdup(mp, filename);
if (d == NULL) return NULL;
p = strrchr(d, '/');
if (p != NULL) d = p + 1;
p = strrchr(d, '\\');
if (p != NULL) d = p + 1;
return d;
}
/**
*
*/
#ifdef WIN32
char *file_dirname(apr_pool_t *p, const char *filename) {
char *b, *c, *d;
if (filename == NULL) return NULL;
b = apr_pstrdup(p, filename);
if (b == NULL) return NULL;
c = strrchr(b, '/');
if (c != NULL) {
d = strrchr(c, '\\');
if (d != NULL) *d = '\0';
else *c = '\0';
} else {
d = strrchr(b, '\\');
if (d != NULL) *d = '\0';
}
return b;
}
#else
char *file_dirname(apr_pool_t *p, const char *filename) {
char *b, *c;
if (filename == NULL) return NULL;
b = apr_pstrdup(p, filename);
if (b == NULL) return NULL;
c = strrchr(b, '/');
if (c != NULL) *c = '\0';
return b;
}
#endif
/**
*
*/
int hex2bytes_inplace(unsigned char *data, int len) {
unsigned char *d = data;
int i, count = 0;
if ((data == NULL)||(len == 0)) return 0;
for(i = 0; i <= len - 2; i += 2) {
*d++ = x2c(&data[i]);
count++;
}
*d = '\0';
return count;
}
/**
* Converts a series of bytes into its hexadecimal
* representation.
*/
char *bytes2hex(apr_pool_t *pool, unsigned char *data, int len) {
static unsigned char b2hex[] = "0123456789abcdef";
char *hex = NULL;
int i, j;
hex = apr_palloc(pool, (len * 2) + 1);
if (hex == NULL) return NULL;
j = 0;
for(i = 0; i < len; i++) {
hex[j++] = b2hex[data[i] >> 4];
hex[j++] = b2hex[data[i] & 0x0f];
}
hex[j] = 0;
return hex;
}
/**
*
*/
int is_token_char(unsigned char c) {
/* ENH Is the performance important at all? We could use a table instead. */
/* CTLs not allowed */
if ((c <= 32)||(c >= 127)) return 0;
switch(c) {
case '(' :
case ')' :
case '<' :
case '>' :
case '@' :
case ',' :
case ';' :
case ':' :
case '\\' :
case '"' :
case '/' :
case '[' :
case ']' :
case '?' :
case '=' :
return 0;
}
return 1;
}
/**
*
*/
int remove_lf_crlf_inplace(char *text) {
char *p = text;
int count = 0;
if (text == NULL) return -1;
while(*p != '\0') {
count++;
p++;
}
if (count > 0) {
if (*(p - 1) == '\n') {
*(p - 1) = '\0';
if (count > 1) {
if (*(p - 2) == '\r') {
*(p - 2) = '\0';
}
}
}
}
return 1;
}
/**
* Converts a byte given as its hexadecimal representation
* into a proper byte. Handles uppercase and lowercase letters
* but does not check for overflows.
*/
unsigned char x2c(unsigned char *what) {
register unsigned char digit;
digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A') + 10 : (what[0] - '0'));
digit *= 16;
digit += (what[1] >= 'A' ? ((what[1] & 0xdf) - 'A') + 10 : (what[1] - '0'));
return digit;
}
/**
* Converts a single hexadecimal digit into a decimal value.
*/
unsigned char xsingle2c(unsigned char *what) {
register unsigned char digit;
digit = (what[0] >= 'A' ? ((what[0] & 0xdf) - 'A') + 10 : (what[0] - '0'));
return digit;
}
/**
*
*/
char *guess_tmp_dir(apr_pool_t *p) {
char *filename = NULL;
/* ENH Use apr_temp_dir_get instead. */
#ifdef WIN32
filename = apr_pcalloc(p, 256);
if (filename == NULL) return "";
if (GetTempPath(255, filename) != 0) return filename;
#endif
filename = getenv("TMPDIR");
if (filename != NULL) return filename;
filename = getenv("TEMP");
if (filename != NULL) return filename;
filename = getenv("TMP");
if (filename != NULL) return filename;
#if defined NETWARE
return("sys:/tmp/");
#elif defined WIN32
return("");
#else
return("/tmp/");
#endif
}
/**
*
*/
char *current_logtime(apr_pool_t *mp) {
apr_time_exp_t t;
char tstr[100];
apr_size_t len;
apr_time_exp_lt(&t, apr_time_now());
apr_strftime(tstr, &len, 80, "%d/%b/%Y:%H:%M:%S ", &t);
apr_snprintf(tstr + strlen(tstr), 80 - strlen(tstr), "%c%.2d%.2d",
t.tm_gmtoff < 0 ? '-' : '+',
t.tm_gmtoff / (60 * 60), t.tm_gmtoff % (60 * 60));
return apr_pstrdup(mp, tstr);
}
/**
*
*/
char *current_filetime(apr_pool_t *mp) {
apr_time_exp_t t;
char tstr[100];
apr_size_t len;
apr_time_exp_lt(&t, apr_time_now());
apr_strftime(tstr, &len, 80, "%Y%m%d-%H%M%S", &t);
return apr_pstrdup(mp, tstr);
}
/**
*
*/
int msc_mkstemp_ex(char *template, int mode) {
int fd = -1;
/* ENH Use apr_file_mktemp instead. */
#if !(defined(WIN32)||defined(NETWARE))
fd = mkstemp(template);
#ifdef HAVE_FCHMOD
if ((fd != -1) && (mode != 0)) {
if (fchmod(fd, mode) == -1) {
return -1;
}
}
#endif /* HAVE_FCHMOD */
#else
if (mktemp(template) == NULL) return -1;
fd = open(template, O_WRONLY | O_APPEND | O_CREAT | O_BINARY, mode);
#endif /* !(defined(WIN32)||defined(NETWARE)) */
return fd;
}
/**
*
*/
int msc_mkstemp(char *template) {
return msc_mkstemp_ex(template, CREATEMODE_UNISTD);
}
/**
* Converts the input string to lowercase (in-place).
*/
char *strtolower_inplace(unsigned char *str) {
unsigned char *c = str;
if (str == NULL) return NULL;
while(*c != 0) {
*c = tolower(*c);
c++;
}
return (char *)str;
}
/**
* Converts a single byte into its hexadecimal representation.
* Will overwrite two bytes at the destination.
*/
unsigned char *c2x(unsigned what, unsigned char *where) {
static const char c2x_table[] = "0123456789abcdef";
what = what & 0xff;
*where++ = c2x_table[what >> 4];
*where++ = c2x_table[what & 0x0f];
return where;
}
char *log_escape(apr_pool_t *mp, const char *text) {
return _log_escape(mp, (const unsigned char *)text, text ? strlen(text) : 0, 1, 0);
}
char *log_escape_nq(apr_pool_t *mp, const char *text) {
return _log_escape(mp, (const unsigned char *)text, text ? strlen(text) : 0, 0, 0);
}
char *log_escape_ex(apr_pool_t *mp, const char *text, unsigned long int text_length) {
return _log_escape(mp, (const unsigned char *)text, text_length, 1, 0);
}
char *log_escape_nq_ex(apr_pool_t *mp, const char *text, unsigned long int text_length) {
return _log_escape(mp, (const unsigned char *)text, text_length, 0, 0);
}
char *log_escape_header_name(apr_pool_t *mp, const char *text) {
return _log_escape(mp, (const unsigned char *)text, text ? strlen(text) : 0, 0, 1);
}
char *log_escape_raw(apr_pool_t *mp, const unsigned char *text, unsigned long int text_length) {
unsigned char *ret = apr_palloc(mp, text_length * 4 + 1);
unsigned long int i, j;
for (i = 0, j = 0; i < text_length; i++, j += 4) {
ret[j] = '\\';
ret[j+1] = 'x';
c2x(text[i], ret+j+2);
}
ret[text_length * 4] = '\0';
return (char *)ret;
}
char *log_escape_nul(apr_pool_t *mp, const unsigned char *text, unsigned long int text_length) {
unsigned char *ret = apr_palloc(mp, text_length * 4 + 1);
unsigned long int i, j;
for (i = 0, j = 0; i < text_length; i++) {
if (text[i] == '\0') {
ret[j] = '\\';
ret[j+1] = 'x';
c2x(text[i], ret+j+2);
j += 4;
}
else {
ret[j] = text[i];
j++;
}
}
ret[j] = '\0';
return (char *)ret;
}
/**
* Transform text to ASCII printable or hex escaped
*/
char *log_escape_hex(apr_pool_t *mp, const unsigned char *text, unsigned long int text_length) {
unsigned char *ret = apr_palloc(mp, text_length * 4 + 1);
unsigned long int i, j;
for (i = 0, j = 0; i < text_length; i++) {
if ( (text[i] == '"')
||(text[i] == '\\')
||(text[i] <= 0x1f)
||(text[i] >= 0x7f))
{
ret[j] = '\\';
ret[j+1] = 'x';
c2x(text[i], ret+j+2);
j += 4;
}
else {
ret[j] = text[i];
j ++;
}
}
ret[j] = '\0';
return (char *)ret;
}
/**
* Transform input into a form safe for logging.
*/
char *_log_escape(apr_pool_t *mp, const unsigned char *input, unsigned long int input_len,
int escape_quotes, int escape_colon)
{
unsigned char *d = NULL;
char *ret = NULL;
unsigned long int i;
if (input == NULL) return NULL;
ret = apr_palloc(mp, input_len * 4 + 1);
if (ret == NULL) return NULL;
d = (unsigned char *)ret;
i = 0;
while(i < input_len) {
switch(input[i]) {
case ':' :
if (escape_colon) {
*d++ = '\\';
*d++ = ':';
} else {
*d++ = input[i];
}
break;
case '"' :
if (escape_quotes) {
*d++ = '\\';
*d++ = '"';
} else {
*d++ = input[i];
}
break;
case '\b' :
*d++ = '\\';
*d++ = 'b';
break;
case '\n' :
*d++ = '\\';
*d++ = 'n';
break;
case '\r' :
*d++ = '\\';
*d++ = 'r';
break;
case '\t' :
*d++ = '\\';
*d++ = 't';
break;
case '\v' :
*d++ = '\\';
*d++ = 'v';
break;
case '\\' :
*d++ = '\\';
*d++ = '\\';
break;
default :
if ((input[i] <= 0x1f)||(input[i] >= 0x7f)) {
*d++ = '\\';
*d++ = 'x';
c2x(input[i], d);
d += 2;
} else {
*d++ = input[i];
}
break;
}
i++;
}
*d = 0;
return ret;
}
/**
* JavaScript decoding.
* IMP1 Assumes NUL-terminated
*/
int js_decode_nonstrict_inplace(unsigned char *input, long int input_len) {
unsigned char *d = (unsigned char *)input;
long int i, count;
if (input == NULL) return -1;
i = count = 0;
while (i < input_len) {
if (input[i] == '\\') {
/* Character is an escape. */
if ( (i + 5 < input_len) && (input[i + 1] == 'u')
&& (VALID_HEX(input[i + 2])) && (VALID_HEX(input[i + 3]))
&& (VALID_HEX(input[i + 4])) && (VALID_HEX(input[i + 5])) )
{
/* \uHHHH */
/* Use only the lower byte. */
*d = x2c(&input[i + 4]);
/* Full width ASCII (ff01 - ff5e) needs 0x20 added */
if ( (*d > 0x00) && (*d < 0x5f)
&& ((input[i + 2] == 'f') || (input[i + 2] == 'F'))
&& ((input[i + 3] == 'f') || (input[i + 3] == 'F')))
{
(*d) += 0x20;
}
d++;
count++;
i += 6;
}
else if ( (i + 3 < input_len) && (input[i + 1] == 'x')
&& VALID_HEX(input[i + 2]) && VALID_HEX(input[i + 3])) {
/* \xHH */
*d++ = x2c(&input[i + 2]);
count++;
i += 4;
}
else if ((i + 1 < input_len) && ISODIGIT(input[i + 1])) {
/* \OOO (only one byte, \000 - \377) */
char buf[4];
int j = 0;
while((i + 1 + j < input_len)&&(j < 3)) {
buf[j] = input[i + 1 + j];
j++;
if (!ISODIGIT(input[i + 1 + j])) break;
}
buf[j] = '\0';
if (j > 0) {
/* Do not use 3 characters if we will be > 1 byte */
if ((j == 3) && (buf[0] > '3')) {
j = 2;
buf[j] = '\0';
}
*d++ = (unsigned char)strtol(buf, NULL, 8);
i += 1 + j;
count++;
}
}
else if (i + 1 < input_len) {
/* \C */
unsigned char c = input[i + 1];
switch(input[i + 1]) {
case 'a' :
c = '\a';
break;
case 'b' :
c = '\b';
break;
case 'f' :
c = '\f';
break;
case 'n' :
c = '\n';
break;
case 'r' :
c = '\r';
break;
case 't' :
c = '\t';
break;
case 'v' :
c = '\v';
break;
/* The remaining (\?,\\,\',\") are just a removal
* of the escape char which is default.
*/
}
*d++ = c;
i += 2;
count++;
}
else {
/* Not enough bytes */
while(i < input_len) {
*d++ = input[i++];
count++;
}
}
}
else {
*d++ = input[i++];
count++;
}
}
*d = '\0';
return count;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
int urldecode_uni_nonstrict_inplace_ex(unsigned char *input, long int input_len, int *changed) {
unsigned char *d = input;
long int i, count;
*changed = 0;
if (input == NULL) return -1;
i = count = 0;
while (i < input_len) {
if (input[i] == '%') {
/* Character is a percent sign. */
if ((i + 1 < input_len)&&( (input[i + 1] == 'u')||(input[i + 1] == 'U') )) {
/* IIS-specific %u encoding. */
if (i + 5 < input_len) {
/* We have at least 4 data bytes. */
if ( (VALID_HEX(input[i + 2]))&&(VALID_HEX(input[i + 3]))
&&(VALID_HEX(input[i + 4]))&&(VALID_HEX(input[i + 5])) )
{
/* We first make use of the lower byte here, ignoring the higher byte. */
*d = x2c(&input[i + 4]);
/* Full width ASCII (ff01 - ff5e) needs 0x20 added */
if ( (*d > 0x00) && (*d < 0x5f)
&& ((input[i + 2] == 'f') || (input[i + 2] == 'F'))
&& ((input[i + 3] == 'f') || (input[i + 3] == 'F')))
{
(*d) += 0x20;
}
d++;
count++;
i += 6;
*changed = 1;
} else {
/* Invalid data, skip %u. */
*d++ = input[i++];
*d++ = input[i++];
count += 2;
}
} else {
/* Not enough bytes (4 data bytes), skip %u. */
*d++ = input[i++];
*d++ = input[i++];
count += 2;
}
}
else {
/* Standard URL encoding. */
/* Are there enough bytes available? */
if (i + 2 < input_len) {
/* Yes. */
/* Decode a %xx combo only if it is valid.
*/
char c1 = input[i + 1];
char c2 = input[i + 2];
if (VALID_HEX(c1) && VALID_HEX(c2)) {
*d++ = x2c(&input[i + 1]);
count++;
i += 3;
*changed = 1;
} else {
/* Not a valid encoding, skip this % */
*d++ = input[i++];
count++;
}
} else {
/* Not enough bytes available, skip this % */
*d++ = input[i++];
count++;
}
}
}
else {
/* Character is not a percent sign. */
if (input[i] == '+') {
*d++ = ' ';
*changed = 1;
} else {
*d++ = input[i];
}
count++;
i++;
}
}
*d = '\0';
return count;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
int urldecode_nonstrict_inplace_ex(unsigned char *input, long int input_len, int *invalid_count, int *changed) {
unsigned char *d = (unsigned char *)input;
long int i, count;
*changed = 0;
if (input == NULL) return -1;
i = count = 0;
while (i < input_len) {
if (input[i] == '%') {
/* Character is a percent sign. */
/* Are there enough bytes available? */
if (i + 2 < input_len) {
char c1 = input[i + 1];
char c2 = input[i + 2];
if (VALID_HEX(c1) && VALID_HEX(c2)) {
/* Valid encoding - decode it. */
*d++ = x2c(&input[i + 1]);
count++;
i += 3;
*changed = 1;
} else {
/* Not a valid encoding, skip this % */
*d++ = input[i++];
count ++;
(*invalid_count)++;
}
} else {
/* Not enough bytes available, copy the raw bytes. */
*d++ = input[i++];
count ++;
(*invalid_count)++;
}
} else {
/* Character is not a percent sign. */
if (input[i] == '+') {
*d++ = ' ';
*changed = 1;
} else {
*d++ = input[i];
}
count++;
i++;
}
}
*d = '\0';
return count;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
int html_entities_decode_inplace(apr_pool_t *mp, unsigned char *input, int input_len) {
unsigned char *d = input;
int i, count;
if ((input == NULL)||(input_len <= 0)) return 0;
i = count = 0;
while((i < input_len)&&(count < input_len)) {
int z, copy = 1;
/* Require an ampersand and at least one character to
* start looking into the entity.
*/
if ((input[i] == '&')&&(i + 1 < input_len)) {
int k, j = i + 1;
if (input[j] == '#') {
/* Numerical entity. */
copy++;
if (!(j + 1 < input_len)) goto HTML_ENT_OUT; /* Not enough bytes. */
j++;
if ((input[j] == 'x')||(input[j] == 'X')) {
/* Hexadecimal entity. */
copy++;
if (!(j + 1 < input_len)) goto HTML_ENT_OUT; /* Not enough bytes. */
j++; /* j is the position of the first digit now. */
k = j;
while((j < input_len)&&(isxdigit(input[j]))) j++;
if (j > k) { /* Do we have at least one digit? */
/* Decode the entity. */
char *x = apr_pstrmemdup(mp, (const char *)&input[k], j - k);
*d++ = (unsigned char)strtol(x, NULL, 16);
count++;
/* Skip over the semicolon if it's there. */
if ((j < input_len)&&(input[j] == ';')) i = j + 1;
else i = j;
continue;
} else {
goto HTML_ENT_OUT;
}
} else {
/* Decimal entity. */
k = j;
while((j < input_len)&&(isdigit(input[j]))) j++;
if (j > k) { /* Do we have at least one digit? */
/* Decode the entity. */
char *x = apr_pstrmemdup(mp, (const char *)&input[k], j - k);
*d++ = (unsigned char)strtol(x, NULL, 10);
count++;
/* Skip over the semicolon if it's there. */
if ((j < input_len)&&(input[j] == ';')) i = j + 1;
else i = j;
continue;
} else {
goto HTML_ENT_OUT;
}
}
} else {
/* Text entity. */
k = j;
while((j < input_len)&&(isalnum(input[j]))) j++;
if (j > k) { /* Do we have at least one digit? */
char *x = apr_pstrmemdup(mp, (const char *)&input[k], j - k);
/* Decode the entity. */
/* ENH What about others? */
if (strcasecmp(x, "quot") == 0) *d++ = '"';
else
if (strcasecmp(x, "amp") == 0) *d++ = '&';
else
if (strcasecmp(x, "lt") == 0) *d++ = '<';
else
if (strcasecmp(x, "gt") == 0) *d++ = '>';
else
if (strcasecmp(x, "nbsp") == 0) *d++ = NBSP;
else {
/* We do no want to convert this entity, copy the raw data over. */
copy = j - k + 1;
goto HTML_ENT_OUT;
}
count++;
/* Skip over the semicolon if it's there. */
if ((j < input_len)&&(input[j] == ';')) i = j + 1;
else i = j;
continue;
}
}
}
HTML_ENT_OUT:
for(z = 0; ((z < copy) && (count < input_len)); z++) {
*d++ = input[i++];
count++;
}
}
*d = '\0';
return count;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
int ansi_c_sequences_decode_inplace(unsigned char *input, int input_len) {
unsigned char *d = input;
int i, count;
i = count = 0;
while(i < input_len) {
if ((input[i] == '\\')&&(i + 1 < input_len)) {
int c = -1;
switch(input[i + 1]) {
case 'a' :
c = '\a';
break;
case 'b' :
c = '\b';
break;
case 'f' :
c = '\f';
break;
case 'n' :
c = '\n';
break;
case 'r' :
c = '\r';
break;
case 't' :
c = '\t';
break;
case 'v' :
c = '\v';
break;
case '\\' :
c = '\\';
break;
case '?' :
c = '?';
break;
case '\'' :
c = '\'';
break;
case '"' :
c = '"';
break;
}
if (c != -1) i += 2;
/* Hexadecimal or octal? */
if (c == -1) {
if ((input[i + 1] == 'x')||(input[i + 1] == 'X')) {
/* Hexadecimal. */
if ((i + 3 < input_len)&&(isxdigit(input[i + 2]))&&(isxdigit(input[i + 3]))) {
/* Two digits. */
c = x2c(&input[i + 2]);
i += 4;
} else {
/* Invalid encoding, do nothing. */
}
}
else
if (ISODIGIT(input[i + 1])) { /* Octal. */
char buf[4];
int j = 0;
while((i + 1 + j < input_len)&&(j < 3)) {
buf[j] = input[i + 1 + j];
j++;
if (!ISODIGIT(input[i + 1 + j])) break;
}
buf[j] = '\0';
if (j > 0) {
c = strtol(buf, NULL, 8);
i += 1 + j;
}
}
}
if (c == -1) {
/* Didn't recognise encoding, copy raw bytes. */
*d++ = input[i + 1];
count++;
i += 2;
} else {
/* Converted the encoding. */
*d++ = c;
count++;
}
} else {
/* Input character not a backslash, copy it. */
*d++ = input[i++];
count++;
}
}
*d = '\0';
return count;
}
/**
*
* IMP1 Assumes NUL-terminated
*/
int normalize_path_inplace(unsigned char *input, int input_len, int win, int *changed) {
unsigned char *src;
unsigned char *dst;
unsigned char *end;
int ldst = 0;
int hitroot = 0;
int done = 0;
int relative;
int trailing;
*changed = 0;
/* Need at least one byte to normalize */
if (input_len <= 0) return 0;
/*
* ENH: Deal with UNC and drive letters?
*/
src = dst = input;
end = input + (input_len - 1);
ldst = 1;
relative = ((*input == '/') || (win && (*input == '\\'))) ? 0 : 1;
trailing = ((*end == '/') || (win && (*end == '\\'))) ? 1 : 0;
while (!done && (src <= end) && (dst <= end)) {
/* Convert backslash to forward slash on Windows only. */
if (win) {
if (*src == '\\') {
*src = '/';
*changed = 1;
}
if ((src < end) && (*(src + 1) == '\\')) {
*(src + 1) = '/';
*changed = 1;
}
}
/* Always normalize at the end of the input. */
if (src == end) {
done = 1;
}
/* Skip normalization if this is NOT the end of the path segment. */
else if (*(src + 1) != '/') {
goto copy; /* Skip normalization. */
}
/*** Normalize the path segment. ***/
/* Could it be an empty path segment? */
if ((src != end) && *src == '/') {
/* Ignore */
*changed = 1;
goto copy; /* Copy will take care of this. */
}
/* Could it be a back or self reference? */
else if (*src == '.') {
/* Back-reference? */
if ((dst > input) && (*(dst - 1) == '.')) {
/* If a relative path and either our normalization has
* already hit the rootdir, or this is a backref with no
* previous path segment, then mark that the rootdir was hit
* and just copy the backref as no normilization is possible.
*/
if (relative && (hitroot || ((dst - 2) <= input))) {
hitroot = 1;
goto copy; /* Skip normalization. */
}
/* Remove backreference and the previous path segment. */
dst -= 3;
while ((dst > input) && (*dst != '/')) {
dst--;
}
/* But do not allow going above rootdir. */
if (dst <= input) {
hitroot = 1;
dst = input;
/* Need to leave the root slash if this
* is not a relative path and the end was reached
* on a backreference.
*/
if (!relative && (src == end)) {
dst++;
}
}
if (done) goto length; /* Skip the copy. */
src++;
*changed = 1;
}
/* Relative Self-reference? */
else if (dst == input) {
*changed = 1;
/* Ignore. */
if (done) goto length; /* Skip the copy. */
src++;
}
/* Self-reference? */
else if (*(dst - 1) == '/') {
*changed = 1;
/* Ignore. */
if (done) goto length; /* Skip the copy. */
dst--;
src++;
}
}
/* Found a regular path segment. */
else if (dst > input) {
hitroot = 0;
}
copy:
/*** Copy the byte if required. ***/
/* Skip to the last forward slash when multiple are used. */
if (*src == '/') {
unsigned char *oldsrc = src;
while ( (src < end)
&& ((*(src + 1) == '/') || (win && (*(src + 1) == '\\'))) )
{
src++;
}
if (oldsrc != src) *changed = 1;
/* Do not copy the forward slash to the root
* if it is not a relative path. Instead
* move over the slash to the next segment.
*/
if (relative && (dst == input)) {
src++;
goto length; /* Skip the copy */
}
}
*(dst++) = *(src++);
length:
ldst = (dst - input);
}
/* Make sure that there is not a trailing slash in the
* normalized form if there was not one in the original form.
*/
if (!trailing && (dst > input) && *(dst - 1) == '/') {
ldst--;
dst--;
}
/* Always NUL terminate */
*dst = '\0';
return ldst;
}
char *modsec_build(apr_pool_t *mp) {
return apr_psprintf(mp, "%02i%02i%02i%1i%02i",
atoi(MODSEC_VERSION_MAJOR),
atoi(MODSEC_VERSION_MINOR),
atoi(MODSEC_VERSION_MAINT),
get_modsec_build_type(NULL),
atoi(MODSEC_VERSION_RELEASE));
}
int is_empty_string(const char *string) {
unsigned int i;
if (string == NULL) return 1;
for(i = 0; string[i] != '\0'; i++) {
if (!isspace(string[i])) {
return 0;
}
}
return 1;
}
char *resolve_relative_path(apr_pool_t *pool, const char *parent_filename, const char *filename) {
if (filename == NULL) return NULL;
// TODO Support paths on operating systems other than Unix.
if (filename[0] == '/') return (char *)filename;
return apr_pstrcat(pool, apr_pstrndup(pool, parent_filename,
strlen(parent_filename) - strlen(apr_filepath_name_get(parent_filename))),
filename, NULL);
}
/**
* Decode a string that contains CSS-escaped characters.
*
* References:
* http://www.w3.org/TR/REC-CSS2/syndata.html#q4
* http://www.unicode.org/roadmaps/
*/
int css_decode_inplace(unsigned char *input, long int input_len) {
unsigned char *d = (unsigned char *)input;
long int i, j, count;
if (input == NULL) return -1;
i = count = 0;
while (i < input_len) {
/* Is the character a backslash? */
if (input[i] == '\\') {
/* Is there at least one more byte? */
if (i + 1 < input_len) {
i++; /* We are not going to need the backslash. */
/* Check for 1-6 hex characters following the backslash */
j = 0;
while ( (j < 6)
&& (i + j < input_len)
&& (VALID_HEX(input[i + j])))
{
j++;
}
if (j > 0) { /* We have at least one valid hexadecimal character. */
int fullcheck = 0;
/* For now just use the last two bytes. */
switch (j) {
/* Number of hex characters */
case 1:
*d++ = xsingle2c(&input[i]);
break;
case 2:
case 3:
/* Use the last two from the end. */
*d++ = x2c(&input[i + j - 2]);
break;
case 4:
/* Use the last two from the end, but request
* a full width check.
*/
*d = x2c(&input[i + j - 2]);
fullcheck = 1;
break;
case 5:
/* Use the last two from the end, but request
* a full width check if the number is greater
* or equal to 0xFFFF.
*/
*d = x2c(&input[i + j - 2]);
/* Do full check if first byte is 0 */
if (input[i] == '0') {
fullcheck = 1;
}
else {
d++;
}
break;
case 6:
/* Use the last two from the end, but request
* a full width check if the number is greater
* or equal to 0xFFFF.
*/
*d = x2c(&input[i + j - 2]);
/* Do full check if first/second bytes are 0 */
if ( (input[i] == '0')
&& (input[i + 1] == '0')
) {
fullcheck = 1;
}
else {
d++;
}
break;
}
/* Full width ASCII (0xff01 - 0xff5e) needs 0x20 added */
if (fullcheck) {
if ( (*d > 0x00) && (*d < 0x5f)
&& ((input[i + j - 3] == 'f') ||
(input[i + j - 3] == 'F'))
&& ((input[i + j - 4] == 'f') ||
(input[i + j - 4] == 'F')))
{
(*d) += 0x20;
}
d++;
}
/* We must ignore a single whitespace after a hex escape */
if ((i + j < input_len) && isspace(input[i + j])) {
j++;
}
/* Move over. */
count++;
i += j;
}
/* No hexadecimal digits after backslash */
else if (input[i] == '\n') {
/* A newline character following backslash is ignored. */
i++;
}
/* The character after backslash is not a hexadecimal digit, nor a newline. */
else {
/* Use one character after backslash as is. */
*d++ = input[i++];
count++;
}
}
/* No characters after backslash. */
else {
/* Do not include backslash in output (continuation to nothing) */
i++;
}
}
/* Character is not a backslash. */
else {
/* Copy one normal character to output. */
*d++ = input[i++];
count++;
}
}
/* Terminate output string. */
*d = '\0';
return count;
}
/**
* Translate UNIX octal umask/mode to APR apr_fileperms_t
*/
apr_fileperms_t mode2fileperms(int mode) {
apr_fileperms_t perms = 0;
if (mode & S_IXOTH) perms |= APR_WEXECUTE;
if (mode & S_IWOTH) perms |= APR_WWRITE;
if (mode & S_IROTH) perms |= APR_WREAD;
if (mode & S_IXGRP) perms |= APR_GEXECUTE;
if (mode & S_IWGRP) perms |= APR_GWRITE;
if (mode & S_IRGRP) perms |= APR_GREAD;
if (mode & S_IXUSR) perms |= APR_UEXECUTE;
if (mode & S_IWUSR) perms |= APR_UWRITE;
if (mode & S_IRUSR) perms |= APR_UREAD;
if (mode & S_ISVTX) perms |= APR_WSTICKY;
if (mode & S_ISGID) perms |= APR_GSETID;
if (mode & S_ISUID) perms |= APR_USETID;
return perms;
}
/**
* Generate a single variable.
*/
char *construct_single_var(modsec_rec *msr, char *name) {
char *varname = NULL;
char *param = NULL;
msre_var *var = NULL;
msre_var *vx = NULL;
char *my_error_msg = NULL;
/* Extract variable name and its parameter from the script. */
varname = apr_pstrdup(msr->mp, name);
param = strchr(varname, '.');
if (param != NULL) {
*param = '\0';
param++;
}
/* Resolve variable. */
var = msre_create_var_ex(msr->mp, msr->modsecurity->msre,
varname, param, msr, &my_error_msg);
if (var == NULL) return NULL;
/* Generate variable. */
vx = generate_single_var(msr, var, NULL, NULL, msr->msc_rule_mptmp);
if (vx == NULL) return NULL;
return (char *)vx->value;
}
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