revert stricter key type / signature type checking in userauth path;

too much software generates inconsistent messages, so we need a
better plan.

diff --git a/usr.bin/ssh/auth2-pubkey.c b/usr.bin/ssh/auth2-pubkey.c
index 1f25650..da0aa4f 100644 (file)
--- a/usr.bin/ssh/auth2-pubkey.c
+++ b/usr.bin/ssh/auth2-pubkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-pubkey.c,v 1.73 2017/12/19 00:24:34 djm Exp $ */
+/* $OpenBSD: auth2-pubkey.c,v 1.74 2017/12/21 00:00:28 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -211,7 +211,7 @@ userauth_pubkey(struct ssh *ssh)
                authenticated = 0;
                if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) &&
                    PRIVSEP(sshkey_verify(key, sig, slen, sshbuf_ptr(b),
-                   sshbuf_len(b), pkalg, ssh->compat)) == 0) {
+                   sshbuf_len(b), NULL, ssh->compat)) == 0) {
                        authenticated = 1;
                }
                sshbuf_free(b);

diff --git a/usr.bin/ssh/monitor.c b/usr.bin/ssh/monitor.c
index 49c6237..d3396b8 100644 (file)
--- a/usr.bin/ssh/monitor.c
+++ b/usr.bin/ssh/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.176 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: monitor.c,v 1.177 2017/12/21 00:00:28 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1062,6 +1062,12 @@ mm_answer_keyverify(int sock, struct sshbuf *m)
          !monitor_allowed_key(blob, bloblen))
                fatal("%s: bad key, not previously allowed", __func__);
 
+       /* Empty signature algorithm means NULL. */
+       if (*sigalg == '\0') {
+               free(sigalg);
+               sigalg = NULL;
+       }
+
        /* XXX use sshkey_froms here; need to change key_blob, etc. */
        if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
                fatal("%s: bad public key blob: %s", __func__, ssh_err(r));
@@ -1092,6 +1098,7 @@ mm_answer_keyverify(int sock, struct sshbuf *m)
        free(blob);
        free(signature);
        free(data);
+       free(sigalg);
 
        monitor_reset_key_state();
 

diff --git a/usr.bin/ssh/monitor_wrap.c b/usr.bin/ssh/monitor_wrap.c
index 8065488..fd1e20f 100644 (file)
--- a/usr.bin/ssh/monitor_wrap.c
+++ b/usr.bin/ssh/monitor_wrap.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor_wrap.c,v 1.96 2017/12/18 02:25:15 djm Exp $ */
+/* $OpenBSD: monitor_wrap.c,v 1.97 2017/12/21 00:00:28 djm Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -440,7 +440,7 @@ mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
        buffer_put_string(&m, blob, len);
        buffer_put_string(&m, sig, siglen);
        buffer_put_string(&m, data, datalen);
-       buffer_put_cstring(&m, sigalg);
+       buffer_put_cstring(&m, sigalg == NULL ? "" : sigalg);
        free(blob);
 
        mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);