/*
* Copyright 1996-2014 Daniel Stenberg <daniel@haxx.se>.
* Copyright 2014 Michael Steinert
*
* All rights reserved.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF THIRD PARTY RIGHTS.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
* DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
* OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
* USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* Except as contained in this notice, the name of a copyright holder shall
* not be used in advertising or otherwise to promote the sale, use or other
* dealings in this Software without prior written authorization of the
* copyright holder.
*/
#include "amqp_hostcheck.h"
#include <string.h>
/* Portable, consistent toupper (remember EBCDIC). Do not use toupper()
* because its behavior is altered by the current locale.
*/
static char amqp_raw_toupper(char in) {
switch (in) {
case 'a':
return 'A';
case 'b':
return 'B';
case 'c':
return 'C';
case 'd':
return 'D';
case 'e':
return 'E';
case 'f':
return 'F';
case 'g':
return 'G';
case 'h':
return 'H';
case 'i':
return 'I';
case 'j':
return 'J';
case 'k':
return 'K';
case 'l':
return 'L';
case 'm':
return 'M';
case 'n':
return 'N';
case 'o':
return 'O';
case 'p':
return 'P';
case 'q':
return 'Q';
case 'r':
return 'R';
case 's':
return 'S';
case 't':
return 'T';
case 'u':
return 'U';
case 'v':
return 'V';
case 'w':
return 'W';
case 'x':
return 'X';
case 'y':
return 'Y';
case 'z':
return 'Z';
}
return in;
}
/*
* amqp_raw_equal() is for doing "raw" case insensitive strings. This is meant
* to be locale independent and only compare strings we know are safe for
* this. See http://daniel.haxx.se/blog/2008/10/15/strcasecmp-in-turkish/ for
* some further explanation to why this function is necessary.
*
* The function is capable of comparing a-z case insensitively even for
* non-ascii.
*/
static int amqp_raw_equal(const char *first, const char *second) {
while (*first && *second) {
if (amqp_raw_toupper(*first) != amqp_raw_toupper(*second)) {
/* get out of the loop as soon as they don't match */
break;
}
first++;
second++;
}
/* we do the comparison here (possibly again), just to make sure that if
* the loop above is skipped because one of the strings reached zero, we
* must not return this as a successful match
*/
return (amqp_raw_toupper(*first) == amqp_raw_toupper(*second));
}
static int amqp_raw_nequal(const char *first, const char *second, size_t max) {
while (*first && *second && max) {
if (amqp_raw_toupper(*first) != amqp_raw_toupper(*second)) {
break;
}
max--;
first++;
second++;
}
if (0 == max) {
return 1; /* they are equal this far */
}
return amqp_raw_toupper(*first) == amqp_raw_toupper(*second);
}
/*
* Match a hostname against a wildcard pattern.
* E.g.
* "foo.host.com" matches "*.host.com".
*
* We use the matching rule described in RFC6125, section 6.4.3.
* http://tools.ietf.org/html/rfc6125#section-6.4.3
*/
static amqp_hostcheck_result amqp_hostmatch(const char *hostname,
const char *pattern) {
const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
int wildcard_enabled;
size_t prefixlen, suffixlen;
pattern_wildcard = strchr(pattern, '*');
if (pattern_wildcard == NULL) {
return amqp_raw_equal(pattern, hostname) ? AMQP_HCR_MATCH
: AMQP_HCR_NO_MATCH;
}
/* We require at least 2 dots in pattern to avoid too wide wildcard match. */
wildcard_enabled = 1;
pattern_label_end = strchr(pattern, '.');
if (pattern_label_end == NULL || strchr(pattern_label_end + 1, '.') == NULL ||
pattern_wildcard > pattern_label_end ||
amqp_raw_nequal(pattern, "xn--", 4)) {
wildcard_enabled = 0;
}
if (!wildcard_enabled) {
return amqp_raw_equal(pattern, hostname) ? AMQP_HCR_MATCH
: AMQP_HCR_NO_MATCH;
}
hostname_label_end = strchr(hostname, '.');
if (hostname_label_end == NULL ||
!amqp_raw_equal(pattern_label_end, hostname_label_end)) {
return AMQP_HCR_NO_MATCH;
}
/* The wildcard must match at least one character, so the left-most
* label of the hostname is at least as large as the left-most label
* of the pattern.
*/
if (hostname_label_end - hostname < pattern_label_end - pattern) {
return AMQP_HCR_NO_MATCH;
}
prefixlen = pattern_wildcard - pattern;
suffixlen = pattern_label_end - (pattern_wildcard + 1);
return amqp_raw_nequal(pattern, hostname, prefixlen) &&
amqp_raw_nequal(pattern_wildcard + 1,
hostname_label_end - suffixlen, suffixlen)
? AMQP_HCR_MATCH
: AMQP_HCR_NO_MATCH;
}
amqp_hostcheck_result amqp_hostcheck(const char *match_pattern,
const char *hostname) {
/* sanity check */
if (!match_pattern || !*match_pattern || !hostname || !*hostname) {
return AMQP_HCR_NO_MATCH;
}
/* trivial case */
if (amqp_raw_equal(hostname, match_pattern)) {
return AMQP_HCR_MATCH;
}
return amqp_hostmatch(hostname, match_pattern);
}