svn commit: r303832 - head/crypto/openssh

[Dag-Erling Smørgrav]

Author: des
Date: Mon Aug  8 10:46:18 2016
New Revision: 303832
URL: https://svnweb.freebsd.org/changeset/base/303832

Log:
  Try to check whether each key file exists before adding it, and bail out
  if we didn't find any of them.  This reduces log spam about key files for
  deprecated algorithms, which we look for but don't generate.
  
  PR:		208254
  MFC after:	3 days

Modified:
  head/crypto/openssh/servconf.c

Modified: head/crypto/openssh/servconf.c
==============================================================================
--- head/crypto/openssh/servconf.c	Mon Aug  8 08:20:10 2016	(r303831)
+++ head/crypto/openssh/servconf.c	Mon Aug  8 10:46:18 2016	(r303832)
@@ -22,6 +22,7 @@ __RCSID("$FreeBSD$");
 #include <netinet/ip.h>
 
 #include <ctype.h>
+#include <fcntl.h>
 #include <netdb.h>
 #include <pwd.h>
 #include <stdio.h>
@@ -206,24 +207,28 @@ fill_default_server_options(ServerOption
 	/* Standard Options */
 	if (options->protocol == SSH_PROTO_UNKNOWN)
 		options->protocol = SSH_PROTO_2;
+#define add_host_key_file(path)						\
+	do {								\
+		if (access((path), O_RDONLY) == 0)			\
+			options->host_key_files				\
+			    [options->num_host_key_files++] = (path);	\
+	} while (0)
 	if (options->num_host_key_files == 0) {
 		/* fill default hostkeys for protocols */
 		if (options->protocol & SSH_PROTO_1)
-			options->host_key_files[options->num_host_key_files++] =
-			    _PATH_HOST_KEY_FILE;
+			add_host_key_file(_PATH_HOST_KEY_FILE);
 		if (options->protocol & SSH_PROTO_2) {
-			options->host_key_files[options->num_host_key_files++] =
-			    _PATH_HOST_RSA_KEY_FILE;
-			options->host_key_files[options->num_host_key_files++] =
-			    _PATH_HOST_DSA_KEY_FILE;
+			add_host_key_file(_PATH_HOST_RSA_KEY_FILE);
+			add_host_key_file(_PATH_HOST_DSA_KEY_FILE);
 #ifdef OPENSSL_HAS_ECC
-			options->host_key_files[options->num_host_key_files++] =
-			    _PATH_HOST_ECDSA_KEY_FILE;
+			add_host_key_file(_PATH_HOST_ECDSA_KEY_FILE);
 #endif
-			options->host_key_files[options->num_host_key_files++] =
-			    _PATH_HOST_ED25519_KEY_FILE;
+			add_host_key_file(_PATH_HOST_ED25519_KEY_FILE);
 		}
 	}
+#undef add_host_key_file
+	if (options->num_host_key_files == 0)
+		fatal("No host key files found");
 	/* No certificates by default */
 	if (options->num_ports == 0)
 		options->ports[options->num_ports++] = SSH_DEFAULT_PORT;