hsts: ignore numberical IP address hosts

Also, use a single function library-wide for detecting if a given hostname is
a numerical IP address.

Reported-by: Harry Sintonen
Fixes #7146
Closes #7149

lib/cookie.c

@@ -146,31 +146,6 @@ static bool tailmatch(const char *cooke_domain, const char *hostname)
   return FALSE;
 }
 
-/*
- * isip
- *
- * Returns true if the given string is an IPv4 or IPv6 address (if IPv6 has
- * been enabled while building libcurl, and false otherwise.
- */
-static bool isip(const char *domain)
-{
-  struct in_addr addr;
-#ifdef ENABLE_IPV6
-  struct in6_addr addr6;
-#endif
-
-  if(Curl_inet_pton(AF_INET, domain, &addr)
-#ifdef ENABLE_IPV6
-     || Curl_inet_pton(AF_INET6, domain, &addr6)
-#endif
-    ) {
-    /* domain name given as IP address */
-    return TRUE;
-  }
-
-  return FALSE;
-}
-
 /*
  * matching cookie path and url path
  * RFC6265 5.1.4 Paths and Path-Match
@@ -303,7 +278,7 @@ static size_t cookiehash(const char * const domain)
   const char *top;
   size_t len;
 
-  if(!domain || isip(domain))
+  if(!domain || Curl_host_is_ipnum(domain))
     return 0;
 
   top = get_top_domain(domain, &len);
@@ -645,7 +620,7 @@ Curl_cookie_add(struct Curl_easy *data,
             domain = ":";
 #endif
 
-          is_ip = isip(domain ? domain : whatptr);
+          is_ip = Curl_host_is_ipnum(domain ? domain : whatptr);
 
           if(!domain
              || (is_ip && !strcmp(whatptr, domain))
@@ -996,7 +971,7 @@ Curl_cookie_add(struct Curl_easy *data,
    * must also check that the data handle isn't NULL since the psl code will
    * dereference it.
    */
-  if(data && (domain && co->domain && !isip(co->domain))) {
+  if(data && (domain && co->domain && !Curl_host_is_ipnum(co->domain))) {
     const psl_ctx_t *psl = Curl_psl_use(data);
     int acceptable;
 
@@ -1355,7 +1330,7 @@ struct Cookie *Curl_cookie_getlist(struct CookieInfo *c,
   remove_expired(c);
 
   /* check if host is an IP(v4|v6) address */
-  is_ip = isip(host);
+  is_ip = Curl_host_is_ipnum(host);
 
   co = c->cookies[myhash];
 

lib/hostcheck.c

@@ -36,7 +36,7 @@
 
 #include "hostcheck.h"
 #include "strcase.h"
-#include "inet_pton.h"
+#include "hostip.h"
 
 #include "curl_memory.h"
 /* The last #include file should be: */
@@ -67,10 +67,6 @@ static int hostmatch(char *hostname, char *pattern)
   const char *pattern_label_end, *pattern_wildcard, *hostname_label_end;
   int wildcard_enabled;
   size_t prefixlen, suffixlen;
-  struct in_addr ignored;
-#ifdef ENABLE_IPV6
-  struct sockaddr_in6 si6;
-#endif
 
   /* normalize pattern and hostname by stripping off trailing dots */
   size_t len = strlen(hostname);
@@ -86,12 +82,8 @@ static int hostmatch(char *hostname, char *pattern)
       CURL_HOST_MATCH : CURL_HOST_NOMATCH;
 
   /* detect IP address as hostname and fail the match if so */
-  if(Curl_inet_pton(AF_INET, hostname, &ignored) > 0)
+  if(Curl_host_is_ipnum(hostname))
     return CURL_HOST_NOMATCH;
-#ifdef ENABLE_IPV6
-  if(Curl_inet_pton(AF_INET6, hostname, &si6.sin6_addr) > 0)
-    return CURL_HOST_NOMATCH;
-#endif
 
   /* We require at least 2 dots in pattern to avoid too wide wildcard
      match. */

lib/hostip.c

@@ -460,6 +460,25 @@ Curl_cache_addr(struct Curl_easy *data,
   return dns;
 }
 
+/*
+ * Curl_host_is_ipnum() returns TRUE if the given string is a numerical IPv4
+ * (or IPv6 if supported) address.
+ */
+bool Curl_host_is_ipnum(const char *hostname)
+{
+  struct in_addr in;
+#ifdef ENABLE_IPV6
+  struct in6_addr in6;
+#endif
+  if(Curl_inet_pton(AF_INET, hostname, &in) > 0
+#ifdef ENABLE_IPV6
+     || Curl_inet_pton(AF_INET6, hostname, &in6) > 0
+#endif
+    )
+    return TRUE;
+  return FALSE;
+}
+
 /*
  * Curl_resolv() is the main name resolve function within libcurl. It resolves
  * a name and returns a pointer to the entry in the 'entry' argument (if one

lib/hostip.h

@@ -71,6 +71,8 @@ struct Curl_dns_entry {
   long inuse;
 };
 
+bool Curl_host_is_ipnum(const char *hostname);
+
 /*
  * Curl_resolv() returns an entry with the info for the specified host
  * and port.

lib/hsts.c

@@ -138,6 +138,11 @@ CURLcode Curl_hsts_parse(struct hsts *h, const char *hostname,
   struct stsentry *sts;
   time_t now = time(NULL);
 
+  if(Curl_host_is_ipnum(hostname))
+    /* "explicit IP address identification of all forms is excluded."
+       / RFC 6797 */
+    return CURLE_OK;
+
   do {
     while(*p && ISSPACE(*p))
       p++;

lib/url.c

@@ -92,7 +92,6 @@ bool curl_win32_idn_to_ascii(const char *in, char **out);
 #include "speedcheck.h"
 #include "warnless.h"
 #include "non-ascii.h"
-#include "inet_pton.h"
 #include "getinfo.h"
 #include "urlapi-int.h"
 #include "system_win32.h"