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/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2022, Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
***************************************************************************/
#include "curl_setup.h"
#if defined(USE_OPENSSL) \
|| defined(USE_GSKIT) \
|| defined(USE_SCHANNEL)
/* these backends use functions from this file */
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_NETINET_IN6_H
#include <netinet/in6.h>
#endif
#include "curl_memrchr.h"
#include "hostcheck.h"
#include "strcase.h"
#include "hostip.h"
#include "curl_memory.h"
/* The last #include file should be: */
#include "memdebug.h"
/* check the two input strings with given length, but do not
assume they end in nul-bytes */
static bool pmatch(const char *hostname, size_t hostlen,
const char *pattern, size_t patternlen)
{
if(hostlen != patternlen)
return FALSE;
return strncasecompare(hostname, pattern, hostlen);
}
/*
* 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.
* https://datatracker.ietf.org/doc/html/rfc6125#section-6.4.3
*
* In addition: ignore trailing dots in the host names and wildcards, so that
* the names are used normalized. This is what the browsers do.
*
* Do not allow wildcard matching on IP numbers. There are apparently
* certificates being used with an IP address in the CN field, thus making no
* apparent distinction between a name and an IP. We need to detect the use of
* an IP address and not wildcard match on such names.
*
* Return TRUE on a match. FALSE if not.
*/
static bool hostmatch(const char *hostname, const char *pattern)
{
const char *pattern_label_end, *wildcard, *hostname_label_end;
size_t prefixlen, suffixlen;
/* normalize pattern and hostname by stripping off trailing dots */
size_t patternlen;
size_t hostlen = strlen(hostname);
if(hostname[hostlen-1]=='.')
hostlen--;
patternlen = strlen(pattern);
if(pattern[patternlen-1]=='.')
patternlen--;
wildcard = memchr(pattern, '*', patternlen);
if(!wildcard)
return pmatch(hostname, hostlen, pattern, patternlen);
/* detect IP address as hostname and fail the match if so */
if(Curl_host_is_ipnum(hostname))
return FALSE;
/* We require at least 2 dots in the pattern to avoid too wide wildcard
match. */
pattern_label_end = memchr(pattern, '.', patternlen);
if(!pattern_label_end ||
(memrchr(pattern, '.', patternlen) == pattern_label_end) ||
strncasecompare(pattern, "xn--", 4))
return pmatch(hostname, hostlen, pattern, patternlen);
hostname_label_end = memchr(hostname, '.', hostlen);
if(!hostname_label_end)
return FALSE;
else {
size_t skiphost = hostname_label_end - hostname;
size_t skiplen = pattern_label_end - pattern;
if(!pmatch(hostname_label_end, hostlen - skiphost,
pattern_label_end, patternlen - skiplen))
return FALSE;
}
/* 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 FALSE;
prefixlen = wildcard - pattern;
suffixlen = pattern_label_end - (wildcard + 1);
return strncasecompare(pattern, hostname, prefixlen) &&
strncasecompare(wildcard + 1, hostname_label_end - suffixlen,
suffixlen) ? TRUE : FALSE;
}
/*
* Curl_cert_hostcheck() returns TRUE if a match and FALSE if not.
*/
bool Curl_cert_hostcheck(const char *match, const char *hostname)
{
if(match && *match && hostname && *hostname)
return hostmatch(hostname, match);
return FALSE;
}
#endif /* OPENSSL, GSKIT or schannel+wince */
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