upstream: UpdateHostkeys: fixed/better detection of host keys that

exist under other names and addresses; spotted by and debugged with lots of
help from jca@

OpenBSD-Commit-ID: 5113d7f550bbd48243db1705afbf16b63792d4b7

diff --git a/clientloop.c b/clientloop.c
index f9b18fe0bc7f50f1d007317d719073ee06459ae4..c49eed3980af743873d68c4e260b51ebb7f6fe95 100644 (file)
--- a/clientloop.c
+++ b/clientloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: clientloop.c,v 1.354 2020/10/18 11:32:01 djm Exp $ */
+/* $OpenBSD: clientloop.c,v 1.355 2020/10/29 02:47:23 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1892,13 +1892,20 @@ hostkeys_find(struct hostkey_foreach_line *l, void *_ctx)
                return 0;
        }
 
-       /* Record if address matched against a different hostname. */
-       if (ctx->ip_str != NULL && (l->match & HKF_MATCH_HOST) == 0 &&
-           strchr(l->hosts, ',') != NULL) {
-               ctx->other_name_seen = 1;
-               debug3_f("found address %s against different hostname at "
-                   "%s:%ld", ctx->ip_str, l->path, l->linenum);
-               return 0;
+       /* If CheckHostIP is enabled, then check for mismatched hostname/addr */
+       if (ctx->ip_str != NULL && strchr(l->hosts, ',') != NULL) {
+               if ((l->match & HKF_MATCH_HOST) == 0) {
+                       /* Record if address matched a different hostname. */
+                       ctx->other_name_seen = 1;
+                       debug3_f("found address %s against different hostname "
+                           "at %s:%ld", ctx->ip_str, l->path, l->linenum);
+                       return 0;
+               } else if ((l->match & HKF_MATCH_IP) == 0) {
+                       /* Record if hostname matched a different address. */
+                       ctx->other_name_seen = 1;
+                       debug3_f("found hostname %s against different address "
+                           "at %s:%ld", ctx->host_str, l->path, l->linenum);
+               }
        }
 
        /*
@@ -2291,7 +2298,7 @@ client_input_hostkeys(struct ssh *ssh)
                    ctx->ip_str ? ctx->ip_str : "(none)");
                if ((r = hostkeys_foreach(options.user_hostfiles[i],
                    hostkeys_find, ctx, ctx->host_str, ctx->ip_str,
-                   HKF_WANT_PARSE_KEY|HKF_WANT_MATCH)) != 0) {
+                   HKF_WANT_PARSE_KEY)) != 0) {
                        if (r == SSH_ERR_SYSTEM_ERROR && errno == ENOENT) {
                                debug_f("hostkeys file %s does not exist",
                                    options.user_hostfiles[i]);