curl/lib/vtls/hostcheck.c
Daniel Stenberg 78d6232f1f
gskit: remove
We remove support for building curl with gskit.

 - This is a niche TLS library, only running on some IBM systems
 - no regular curl contributors use this backend
 - no CI builds use or verify this backend
 - gskit, or the curl adaption for it, lacks many modern TLS features
   making it an inferior solution
 - build breakages in this code take weeks or more to get detected
 - fixing gskit code is mostly done "flying blind"

This removal has been advertized in DEPRECATED in Jan 2, 2023 and it has
been mentioned on the curl-library mailing list.

It could be brought back, this is not a ban. Given proper effort and
will, gskit support is welcome back into the curl TLS backend family.

Closes #11460
2023-08-07 20:57:48 +02:00

136 lines
4.2 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 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.
*
* SPDX-License-Identifier: curl
*
***************************************************************************/
#include "curl_setup.h"
#if defined(USE_OPENSSL) \
|| 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.
*
* Only match on "*" being used for the leftmost label, not "a*", "a*b" nor
* "*b".
*
* Return TRUE on a match. FALSE if not.
*
* @unittest: 1397
*/
static bool hostmatch(const char *hostname,
size_t hostlen,
const char *pattern,
size_t patternlen)
{
const char *pattern_label_end;
DEBUGASSERT(pattern);
DEBUGASSERT(patternlen);
DEBUGASSERT(hostname);
DEBUGASSERT(hostlen);
/* normalize pattern and hostname by stripping off trailing dots */
if(hostname[hostlen-1]=='.')
hostlen--;
if(pattern[patternlen-1]=='.')
patternlen--;
if(strncmp(pattern, "*.", 2))
return pmatch(hostname, hostlen, pattern, patternlen);
/* detect IP address as hostname and fail the match if so */
else 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))
return pmatch(hostname, hostlen, pattern, patternlen);
else {
const char *hostname_label_end = memchr(hostname, '.', hostlen);
if(hostname_label_end) {
size_t skiphost = hostname_label_end - hostname;
size_t skiplen = pattern_label_end - pattern;
return pmatch(hostname_label_end, hostlen - skiphost,
pattern_label_end, patternlen - skiplen);
}
}
return FALSE;
}
/*
* Curl_cert_hostcheck() returns TRUE if a match and FALSE if not.
*/
bool Curl_cert_hostcheck(const char *match, size_t matchlen,
const char *hostname, size_t hostlen)
{
if(match && *match && hostname && *hostname)
return hostmatch(hostname, hostlen, match, matchlen);
return FALSE;
}
#endif /* OPENSSL or SCHANNEL */