ModSecurity/src/utils/decode.cc
2023-11-08 17:32:41 +01:00

125 lines
3.3 KiB
C++

/*
* ModSecurity, http://www.modsecurity.org/
* Copyright (c) 2015 - 2021 Trustwave Holdings, Inc. (http://www.trustwave.com/)
*
* 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
*
* 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 security@modsecurity.org.
*
*/
#include "src/utils/decode.h"
#include "modsecurity/modsecurity.h"
#include "src/utils/string.h"
namespace modsecurity {
namespace utils {
int urldecode_nonstrict_inplace(unsigned char *input,
uint64_t input_len, int *invalid_count, int *changed) {
unsigned char *d = (unsigned char *)input;
uint64_t 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)) {
uint64_t uni = string::x2c(&input[i + 1]);
*d++ = (wchar_t)uni;
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++;
}
}
#if 0
*d = '\0';
#endif
return count;
}
std::string uri_decode(const std::string & sSrc) {
// Note from RFC1630: "Sequences which start with a percent
// sign but are not followed by two hexadecimal characters
// (0-9, A-F) are reserved for future extension"
const unsigned char * pSrc = (const unsigned char *)sSrc.c_str();
const int SRC_LEN = sSrc.length();
const unsigned char * const SRC_END = pSrc + SRC_LEN;
// last decodable '%'
const unsigned char * const SRC_LAST_DEC = SRC_END - 2;
char * const pStart = new char[SRC_LEN];
char * pEnd = pStart;
while (pSrc < SRC_LAST_DEC) {
if (*pSrc == '%') {
char dec1, dec2;
if ((char)-1 != (dec1 = string::HEX2DEC[*(pSrc + 1)])
&& (char)-1 != (dec2 = string::HEX2DEC[*(pSrc + 2)])) {
*pEnd++ = (dec1 << 4) + dec2;
pSrc += 3;
continue;
}
}
*pEnd++ = *pSrc++;
}
// the last 2- chars
while (pSrc < SRC_END) {
*pEnd++ = *pSrc++;
}
std::string sResult(pStart, pEnd);
delete [] pStart;
return sResult;
}
} // namespace utils
} // namespace modsecurity