From: Ken Raeburn <raeburn@mit.edu>
Date: Tue, 9 Jul 2002 18:16:00 +0000 (+0000)
Subject: * hst_realm.c (krb5_get_host_realm): Return KRB5_ERR_NUMERIC_REALM if the
X-Git-Tag: krb5-1.3-alpha1~600
X-Git-Url: http://git.tremily.us/?a=commitdiff_plain;h=11c20954ab6a7f1915702b465aa404375489e463;p=krb5.git

* hst_realm.c (krb5_get_host_realm): Return KRB5_ERR_NUMERIC_REALM if the
hostname is a numeric-address form.

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@14619 dc483132-0cff-0310-8789-dd5450dbe970
---

diff --git a/src/lib/krb5/os/ChangeLog b/src/lib/krb5/os/ChangeLog
index 3cbe50c13..a1176306c 100644
--- a/src/lib/krb5/os/ChangeLog
+++ b/src/lib/krb5/os/ChangeLog
@@ -1,3 +1,8 @@
+2002-07-09  Ken Raeburn  <raeburn@mit.edu>
+
+	* hst_realm.c (krb5_get_host_realm): Return KRB5_ERR_NUMERIC_REALM
+	if the hostname is a numeric-address form.
+
 2002-07-08  Ken Raeburn  <raeburn@mit.edu>
 
 	* localaddr.c (get_localaddrs): Split out main body of
diff --git a/src/lib/krb5/os/hst_realm.c b/src/lib/krb5/os/hst_realm.c
index 4238f5e54..2485c8710 100644
--- a/src/lib/krb5/os/hst_realm.c
+++ b/src/lib/krb5/os/hst_realm.c
@@ -280,6 +280,28 @@ krb5_get_host_realm(context, host, realmsp)
     char local_host[MAX_DNS_NAMELEN+1];
 
     if (host) {
+	/* Filter out numeric addresses if the caller utterly failed to
+	   convert them to names.  */
+	/* IPv4 - dotted quads only */
+	if (strspn(host, "01234567890.") == strlen(host)) {
+	    /* All numbers and dots... if it's three dots, it's an
+	       IP address, and we reject it.  But "12345" could be
+	       a local hostname, couldn't it?  We'll just assume
+	       that a name with three dots is not meant to be an
+	       all-numeric hostname three all-numeric domains down
+	       from the current domain.  */
+	    int ndots = 0;
+	    const char *p;
+	    for (p = host; *p; p++)
+		if (*p == '.')
+		    ndots++;
+	    if (ndots == 3)
+		return KRB5_ERR_NUMERIC_REALM;
+	}
+	if (strchr(host, ':'))
+	    /* IPv6 numeric address form?  Bye bye.  */
+	    return KRB5_ERR_NUMERIC_REALM;
+
 	/* Should probably error out if strlen(host) > MAX_DNS_NAMELEN.  */
 	strncpy(local_host, host, sizeof(local_host));
 	local_host[sizeof(local_host) - 1] = '\0';