From 1b9dd4aa15208100fbc3650f33ea052255578282 Mon Sep 17 00:00:00 2001
From: "djm@openbsd.org" <djm@openbsd.org>
Date: Sun, 12 Aug 2018 20:19:13 +0000
Subject: [PATCH] upstream: better diagnosics on alg list assembly errors; ok

deraadt@ markus@

OpenBSD-Commit-ID: 5a557e74b839daf13cc105924d2af06a1560faee
---
 readconf.c | 27 +++++++++++++++------------
 servconf.c | 28 ++++++++++++++--------------
 2 files changed, 29 insertions(+), 26 deletions(-)

diff --git a/readconf.c b/readconf.c
index 4b11bab5e..db5f2d547 100644
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.296 2018/07/27 05:34:42 dtucker Exp $ */
+/* $OpenBSD: readconf.c,v 1.297 2018/08/12 20:19:13 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -53,6 +53,7 @@
 
 #include "xmalloc.h"
 #include "ssh.h"
+#include "ssherr.h"
 #include "compat.h"
 #include "cipher.h"
 #include "pathnames.h"
@@ -1924,6 +1925,7 @@ void
 fill_default_options(Options * options)
 {
 	char *all_cipher, *all_mac, *all_kex, *all_key;
+	int r;
 
 	if (options->forward_agent == -1)
 		options->forward_agent = 0;
@@ -2075,17 +2077,18 @@ fill_default_options(Options * options)
 	all_mac = mac_alg_list(',');
 	all_kex = kex_alg_list(',');
 	all_key = sshkey_alg_list(0, 0, 1, ',');
-	if (kex_assemble_names(&options->ciphers,
-	    KEX_CLIENT_ENCRYPT, all_cipher) != 0 ||
-	    kex_assemble_names(&options->macs,
-	    KEX_CLIENT_MAC, all_mac) != 0 ||
-	    kex_assemble_names(&options->kex_algorithms,
-	    KEX_CLIENT_KEX, all_kex) != 0 ||
-	    kex_assemble_names(&options->hostbased_key_types,
-	    KEX_DEFAULT_PK_ALG, all_key) != 0 ||
-	    kex_assemble_names(&options->pubkey_key_types,
-	    KEX_DEFAULT_PK_ALG, all_key) != 0)
-		fatal("%s: kex_assemble_names failed", __func__);
+#define ASSEMBLE(what, defaults, all) \
+	do { \
+		if ((r = kex_assemble_names(&options->what, \
+		    defaults, all)) != 0) \
+			fatal("%s: %s: %s", __func__, #what, ssh_err(r)); \
+	} while (0)
+	ASSEMBLE(ciphers, KEX_SERVER_ENCRYPT, all_cipher);
+	ASSEMBLE(macs, KEX_SERVER_MAC, all_mac);
+	ASSEMBLE(kex_algorithms, KEX_SERVER_KEX, all_kex);
+	ASSEMBLE(hostbased_key_types, KEX_DEFAULT_PK_ALG, all_key);
+	ASSEMBLE(pubkey_key_types, KEX_DEFAULT_PK_ALG, all_key);
+#undef ASSEMBLE
 	free(all_cipher);
 	free(all_mac);
 	free(all_kex);
diff --git a/servconf.c b/servconf.c
index f1010b3b9..c0f6af0be 100644
--- a/servconf.c
+++ b/servconf.c
@@ -1,5 +1,5 @@
 
-/* $OpenBSD: servconf.c,v 1.339 2018/07/11 18:53:29 markus Exp $ */
+/* $OpenBSD: servconf.c,v 1.340 2018/08/12 20:19:13 djm Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -192,24 +192,24 @@ static void
 assemble_algorithms(ServerOptions *o)
 {
 	char *all_cipher, *all_mac, *all_kex, *all_key;
+	int r;
 
 	all_cipher = cipher_alg_list(',', 0);
 	all_mac = mac_alg_list(',');
 	all_kex = kex_alg_list(',');
 	all_key = sshkey_alg_list(0, 0, 1, ',');
-	if (kex_assemble_names(&o->ciphers,
-	    KEX_SERVER_ENCRYPT, all_cipher) != 0 ||
-	    kex_assemble_names(&o->macs,
-	    KEX_SERVER_MAC, all_mac) != 0 ||
-	    kex_assemble_names(&o->kex_algorithms,
-	    KEX_SERVER_KEX, all_kex) != 0 ||
-	    kex_assemble_names(&o->hostkeyalgorithms,
-	    KEX_DEFAULT_PK_ALG, all_key) != 0 ||
-	    kex_assemble_names(&o->hostbased_key_types,
-	    KEX_DEFAULT_PK_ALG, all_key) != 0 ||
-	    kex_assemble_names(&o->pubkey_key_types,
-	    KEX_DEFAULT_PK_ALG, all_key) != 0)
-		fatal("kex_assemble_names failed");
+#define ASSEMBLE(what, defaults, all) \
+	do { \
+		if ((r = kex_assemble_names(&o->what, defaults, all)) != 0) \
+			fatal("%s: %s: %s", __func__, #what, ssh_err(r)); \
+	} while (0)
+	ASSEMBLE(ciphers, KEX_SERVER_ENCRYPT, all_cipher);
+	ASSEMBLE(macs, KEX_SERVER_MAC, all_mac);
+	ASSEMBLE(kex_algorithms, KEX_SERVER_KEX, all_kex);
+	ASSEMBLE(hostkeyalgorithms, KEX_DEFAULT_PK_ALG, all_key);
+	ASSEMBLE(hostbased_key_types, KEX_DEFAULT_PK_ALG, all_key);
+	ASSEMBLE(pubkey_key_types, KEX_DEFAULT_PK_ALG, all_key);
+#undef ASSEMBLE
 	free(all_cipher);
 	free(all_mac);
 	free(all_kex);