upstream commit

When updating hostkeys, accept RSA keys if
HostkeyAlgorithms contains any RSA keytype. Previously, ssh could ignore RSA
keys when any of the ssh-rsa-sha2-* methods was enabled in HostkeyAlgorithms
nit ssh-rsa (SHA1 signatures) was not. bz#2650 reported by Luis Ressel; ok
dtucker@

Upstream-ID: c5e8cfee15c42f4a05d126158a0766ea06da79d2
This commit is contained in:
djm@openbsd.org 2017-03-10 05:01:13 +00:00 committed by Damien Miller
parent dd3e229866
commit 894221a63f
1 changed files with 22 additions and 5 deletions

View File

@ -1,4 +1,4 @@
/* $OpenBSD: clientloop.c,v 1.290 2017/01/29 21:35:23 dtucker Exp $ */
/* $OpenBSD: clientloop.c,v 1.291 2017/03/10 05:01:13 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -2390,6 +2390,26 @@ client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx)
hostkeys_update_ctx_free(ctx);
}
/*
* Returns non-zero if the key is accepted by HostkeyAlgorithms.
* Made slightly less trivial by the multiple RSA signature algorithm names.
*/
static int
key_accepted_by_hostkeyalgs(const struct sshkey *key)
{
const char *ktype = sshkey_ssh_name(key);
const char *hostkeyalgs = options.hostkeyalgorithms != NULL ?
options.hostkeyalgorithms : KEX_DEFAULT_PK_ALG;
if (key == NULL || key->type == KEY_UNSPEC)
return 0;
if (key->type == KEY_RSA &&
(match_pattern_list("rsa-sha2-256", hostkeyalgs, 0) == 1 ||
match_pattern_list("rsa-sha2-512", hostkeyalgs, 0) == 1))
return 1;
return match_pattern_list(ktype, hostkeyalgs, 0) == 1;
}
/*
* Handle hostkeys-00@openssh.com global request to inform the client of all
* the server's hostkeys. The keys are checked against the user's
@ -2436,10 +2456,7 @@ client_input_hostkeys(void)
sshkey_type(key), fp);
free(fp);
/* Check that the key is accepted in HostkeyAlgorithms */
if (match_pattern_list(sshkey_ssh_name(key),
options.hostkeyalgorithms ? options.hostkeyalgorithms :
KEX_DEFAULT_PK_ALG, 0) != 1) {
if (!key_accepted_by_hostkeyalgs(key)) {
debug3("%s: %s key not permitted by HostkeyAlgorithms",
__func__, sshkey_ssh_name(key));
continue;