From 4635e729462bf3208f1e76e3e186783ac43d064d Mon Sep 17 00:00:00 2001
From: djm <djm>
Date: Thu, 26 May 2005 02:03:31 +0000
Subject: [PATCH]    - jakob@cvs.openbsd.org 2005/04/20 10:05:45      [dns.c]  
    do not try to look up SSHFP for numerical hostname. ok djm@

---
 ChangeLog |  3 +++
 dns.c     | 29 +++++++++++++++++++++++++++--
 2 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 4fa3e20e..bdb6f79b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -20,6 +20,9 @@
      [ssh.1]
      arg to -b is an address, not if_name;
      ok markus@
+   - jakob@cvs.openbsd.org 2005/04/20 10:05:45
+     [dns.c]
+     do not try to look up SSHFP for numerical hostname. ok djm@
 
 20050524
  - (djm) [contrib/caldera/openssh.spec contrib/redhat/openssh.spec]
diff --git a/dns.c b/dns.c
index 140ab604..5a964bc7 100644
--- a/dns.c
+++ b/dns.c
@@ -1,4 +1,4 @@
-/*	$OpenBSD: dns.c,v 1.10 2004/06/21 17:36:31 avsm Exp $	*/
+/*	$OpenBSD: dns.c,v 1.11 2005/04/20 10:05:45 jakob Exp $	*/
 
 /*
  * Copyright (c) 2003 Wesley Griffin. All rights reserved.
@@ -43,7 +43,7 @@
 #include "uuencode.h"
 
 extern char *__progname;
-RCSID("$OpenBSD: dns.c,v 1.10 2004/06/21 17:36:31 avsm Exp $");
+RCSID("$OpenBSD: dns.c,v 1.11 2005/04/20 10:05:45 jakob Exp $");
 
 #ifndef LWRES
 static const char *errset_text[] = {
@@ -142,6 +142,26 @@ dns_read_rdata(u_int8_t *algorithm, u_int8_t *digest_type,
 	return success;
 }
 
+/*
+ * Check if hostname is numerical.
+ * Returns -1 if hostname is numeric, 0 otherwise
+ */
+static int
+is_numeric_hostname(const char *hostname)
+{
+	struct addrinfo hints, *ai;
+
+	memset(&hints, 0, sizeof(hints));
+	hints.ai_socktype = SOCK_DGRAM;
+	hints.ai_flags = AI_NUMERICHOST;
+
+	if (getaddrinfo(hostname, "0", &hints, &ai) == 0) {
+		freeaddrinfo(ai);
+		return -1;
+	}
+
+	return 0;
+}
 
 /*
  * Verify the given hostname, address and host key using DNS.
@@ -171,6 +191,11 @@ verify_host_key_dns(const char *hostname, struct sockaddr *address,
 	if (hostkey == NULL)
 		fatal("No key to look up!");
 
+	if (is_numeric_hostname(hostname)) {
+		debug("skipped DNS lookup for numerical hostname");
+		return -1;
+	}
+
 	result = getrrsetbyname(hostname, DNS_RDATACLASS_IN,
 	    DNS_RDATATYPE_SSHFP, 0, &fingerprints);
 	if (result) {
-- 
2.45.1