upstream: repair PubkeyAcceptedKeyTypes (and friends) after RSA

signature work - returns ability to add/remove/specify algorithms by
wildcard.

Algorithm lists are now fully expanded when the server/client configs
are finalised, so errors are reported early and the config dumps
(e.g. "ssh -G ...") now list the actual algorithms selected.

Clarify that, while wildcards are accepted in algorithm lists, they
aren't full pattern-lists that support negation.

(lots of) feedback, ok markus@

OpenBSD-Commit-ID: a8894c5c81f399a002f02ff4fe6b4fa46b1f3207

1 files changed, 28 insertions, 10 deletions

diff --git a/readconf.c b/readconf.c
index 8d2029547..2bc27075f 100644
--- a/readconf.c
+++ b/readconf.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: readconf.c,v 1.291 2018/06/10 23:45:41 djm Exp $ */
+/* $OpenBSD: readconf.c,v 1.292 2018/07/04 13:49:31 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1936,6 +1936,8 @@ fill_default_options_for_canonicalization(Options *options)
 void
 fill_default_options(Options * options)
 {
+        char *all_cipher, *all_mac, *all_kex, *all_key;
+
         if (options->forward_agent == -1)
                 options->forward_agent = 0;
         if (options->forward_x11 == -1)
@@ -2082,14 +2084,27 @@ fill_default_options(Options * options)
                 options->fingerprint_hash = SSH_FP_HASH_DEFAULT;
         if (options->update_hostkeys == -1)
                 options->update_hostkeys = 0;
-        if (kex_assemble_names(KEX_CLIENT_ENCRYPT, &options->ciphers) != 0 ||
-            kex_assemble_names(KEX_CLIENT_MAC, &options->macs) != 0 ||
-            kex_assemble_names(KEX_CLIENT_KEX, &options->kex_algorithms) != 0 ||
-            kex_assemble_names(KEX_DEFAULT_PK_ALG,
-            &options->hostbased_key_types) != 0 ||
-            kex_assemble_names(KEX_DEFAULT_PK_ALG,
-            &options->pubkey_key_types) != 0)
+
+        /* Expand KEX name lists */
+        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(&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__);
+        free(all_cipher);
+        free(all_mac);
+        free(all_kex);
+        free(all_key);
 
 #define CLEAR_ON_NONE(v) \
         do { \
@@ -2537,11 +2552,14 @@ void
 dump_client_config(Options *o, const char *host)
 {
         int i;
-        char buf[8];
+        char buf[8], *all_key;
 
         /* This is normally prepared in ssh_kex2 */
-        if (kex_assemble_names(KEX_DEFAULT_PK_ALG, &o->hostkeyalgorithms) != 0)
+        all_key = sshkey_alg_list(0, 0, 1, ',');
+        if (kex_assemble_names( &o->hostkeyalgorithms,
+            KEX_DEFAULT_PK_ALG, all_key) != 0)
                 fatal("%s: kex_assemble_names failed", __func__);
+        free(all_key);
 
         /* Most interesting options first: user, host, port */
         dump_cfg_string(oUser, o->user);