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author	Damien Miller <djm@cvs.openbsd.org>	2015-02-20 22:17:22 +0000
committer	Damien Miller <djm@cvs.openbsd.org>	2015-02-20 22:17:22 +0000
commit	c9ba317251bb1d7b46346ee3ac41354b6bfa7ef6 (patch)
tree	d73cd8330f5f3d2739351fc423fd5e48d513b11b
parent	baa9ac356954692ecc751959de48f726abfdc38b (diff)

UpdateHostKeys fixes:

I accidentally changed the format of the hostkeys@openssh.com messages last week without changing the extension name, and this has been causing connection failures for people who are running -current. First reported by sthen@ s/hostkeys@openssh.com/hostkeys-00@openssh.com/ Change the name of the proof message too, and reorder it a little. Also, UpdateHostKeys=ask is incompatible with ControlPersist (no TTY available to read the response) so disable UpdateHostKeys if it is in ask mode and ControlPersist is active (and document this)

Diffstat

-rw-r--r--

usr.bin/ssh/PROTOCOL

-rw-r--r--

usr.bin/ssh/clientloop.c

-rw-r--r--

usr.bin/ssh/monitor.c

-rw-r--r--

usr.bin/ssh/serverloop.c

-rw-r--r--

usr.bin/ssh/ssh.c

-rw-r--r--

usr.bin/ssh/ssh_config.5

-rw-r--r--

usr.bin/ssh/sshd.c

7 files changed, 42 insertions, 30 deletions

diff --git a/usr.bin/ssh/PROTOCOL b/usr.bin/ssh/PROTOCOL
index f9560839ec4..91bfe270d93 100644
--- a/usr.bin/ssh/PROTOCOL
+++ b/usr.bin/ssh/PROTOCOL

@@ -282,15 +282,15 @@ by the client cancel the forwarding of a Unix domain socket.

boolean FALSE

string socket path

-2.5. connection: hostkey update and rotation "hostkeys@openssh.com"

-and "hostkeys-prove@openssh.com"

+2.5. connection: hostkey update and rotation "hostkeys-00@openssh.com"

+and "hostkeys-prove-00@openssh.com"

OpenSSH supports a protocol extension allowing a server to inform

a client of all its protocol v.2 host keys after user-authentication

has completed.

byte SSH_MSG_GLOBAL_REQUEST

- string "hostkeys@openssh.com"

+ string "hostkeys-00@openssh.com"

string[] hostkeys

Upon receiving this message, a client should check which of the

@@ -300,15 +300,15 @@ to request the server prove ownership of the private half of the

key.

byte SSH_MSG_GLOBAL_REQUEST

- string "hostkeys-prove@openssh.com"

+ string "hostkeys-prove-00@openssh.com"

char 1 /* want-reply */

string[] hostkeys

When a server receives this message, it should generate a signature

using each requested key over the following:

+ string "hostkeys-prove-00@openssh.com"

string session identifier

- string "hostkeys-prove@openssh.com"

string hostkey

These signatures should be included in the reply, in the order matching

@@ -453,4 +453,4 @@ respond with a SSH_FXP_STATUS message.

This extension is advertised in the SSH_FXP_VERSION hello with version

"1".

-$OpenBSD: PROTOCOL,v 1.26 2015/02/16 22:13:32 djm Exp $

+$OpenBSD: PROTOCOL,v 1.27 2015/02/20 22:17:21 djm Exp $

diff --git a/usr.bin/ssh/clientloop.c b/usr.bin/ssh/clientloop.c
index ef0ecadd5d0..644a1f2537f 100644
--- a/usr.bin/ssh/clientloop.c
+++ b/usr.bin/ssh/clientloop.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: clientloop.c,v 1.269 2015/02/16 22:13:32 djm Exp $ */

+/* $OpenBSD: clientloop.c,v 1.270 2015/02/20 22:17:21 djm Exp $ */

* Author: Tatu Ylonen <ylo@cs.hut.fi>

@@ -2247,10 +2247,10 @@ client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx)

continue;

/* Prepare data to be signed: session ID, unique string, key */

sshbuf_reset(signdata);

- if ((r = sshbuf_put_string(signdata, ssh->kex->session_id,

+ if ( (r = sshbuf_put_cstring(signdata,

+ "hostkeys-prove-00@openssh.com")) != 0 ||

+ (r = sshbuf_put_string(signdata, ssh->kex->session_id,

ssh->kex->session_id_len)) != 0 ||

- (r = sshbuf_put_cstring(signdata,

- "hostkeys-prove@openssh.com")) != 0 ||

(r = sshkey_puts(ctx->keys[i], signdata)) != 0)

fatal("%s: failed to prepare signature: %s",

__func__, ssh_err(r));

@@ -2282,7 +2282,7 @@ client_global_hostkeys_private_confirm(int type, u_int32_t seq, void *_ctx)

}

- * Handle hostkeys@openssh.com global request to inform the client of all

+ * 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

* HostkeyAlgorithms preference before they are accepted.

@@ -2317,8 +2317,10 @@ client_input_hostkeys(void)

__func__, ssh_err(r));

goto out;

}

- if ((r = sshkey_from_blob(blob, len, &key)) != 0)

- fatal("%s: parse key: %s", __func__, ssh_err(r));

+ if ((r = sshkey_from_blob(blob, len, &key)) != 0) {

+ error("%s: parse key: %s", __func__, ssh_err(r));

+ goto out;

+ }

fp = sshkey_fingerprint(key, options.fingerprint_hash,

SSH_FP_DEFAULT);

debug3("%s: received %s key %s", __func__,

@@ -2358,9 +2360,10 @@ client_input_hostkeys(void)

}

if (ctx->nkeys == 0) {

- error("%s: server sent no hostkeys", __func__);

+ debug("%s: server sent no hostkeys", __func__);

goto out;

}

if ((ctx->keys_seen = calloc(ctx->nkeys,

sizeof(*ctx->keys_seen))) == NULL)

fatal("%s: calloc failed", __func__);

@@ -2400,7 +2403,7 @@ client_input_hostkeys(void)

__func__, ctx->nnew);

if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||

(r = sshpkt_put_cstring(ssh,

- "hostkeys-prove@openssh.com")) != 0 ||

+ "hostkeys-prove-00@openssh.com")) != 0 ||

(r = sshpkt_put_u8(ssh, 1)) != 0) /* bool: want reply */

fatal("%s: cannot prepare packet: %s",

__func__, ssh_err(r));

@@ -2447,7 +2450,7 @@ client_input_global_request(int type, u_int32_t seq, void *ctxt)

want_reply = packet_get_char();

debug("client_input_global_request: rtype %s want_reply %d",

rtype, want_reply);

- if (strcmp(rtype, "hostkeys@openssh.com") == 0)

+ if (strcmp(rtype, "hostkeys-00@openssh.com") == 0)

success = client_input_hostkeys();

if (want_reply) {

packet_start(success ?

diff --git a/usr.bin/ssh/monitor.c b/usr.bin/ssh/monitor.c
index 13b75a62e48..e459ef90841 100644
--- a/usr.bin/ssh/monitor.c
+++ b/usr.bin/ssh/monitor.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: monitor.c,v 1.144 2015/02/16 22:13:32 djm Exp $ */

+/* $OpenBSD: monitor.c,v 1.145 2015/02/20 22:17:21 djm Exp $ */

@@ -599,7 +599,7 @@ mm_answer_sign(int sock, Buffer *m)

u_char *signature;

size_t datlen, siglen;

int r, keyid, is_proof = 0;

- const char proof_req[] = "hostkeys-prove@openssh.com";

+ const char proof_req[] = "hostkeys-prove-00@openssh.com";

debug3("%s", __func__);

@@ -629,9 +629,9 @@ mm_answer_sign(int sock, Buffer *m)

fatal("%s: no hostkey for index %d", __func__, keyid);

if ((sigbuf = sshbuf_new()) == NULL)

fatal("%s: sshbuf_new", __func__);

- if ((r = sshbuf_put_string(sigbuf, session_id2,

+ if ((r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||

+ (r = sshbuf_put_string(sigbuf, session_id2,

session_id2_len) != 0) ||

- (r = sshbuf_put_cstring(sigbuf, proof_req)) != 0 ||

(r = sshkey_puts(key, sigbuf)) != 0)

fatal("%s: couldn't prepare private key "

"proof buffer: %s", __func__, ssh_err(r));

diff --git a/usr.bin/ssh/serverloop.c b/usr.bin/ssh/serverloop.c
index 6b09fbde2f5..e2f60bc6255 100644
--- a/usr.bin/ssh/serverloop.c
+++ b/usr.bin/ssh/serverloop.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: serverloop.c,v 1.177 2015/02/16 22:13:32 djm Exp $ */

+/* $OpenBSD: serverloop.c,v 1.178 2015/02/20 22:17:21 djm Exp $ */

* Author: Tatu Ylonen <ylo@cs.hut.fi>

@@ -1158,10 +1158,10 @@ server_input_hostkeys_prove(struct sshbuf **respp)

sshbuf_reset(sigbuf);

free(sig);

sig = NULL;

- if ((r = sshbuf_put_string(sigbuf,

+ if ((r = sshbuf_put_cstring(sigbuf,

+ "hostkeys-prove-00@openssh.com")) != 0 ||

+ (r = sshbuf_put_string(sigbuf,

ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||

- (r = sshbuf_put_cstring(sigbuf,

- "hostkeys-prove@openssh.com")) != 0 ||

(r = sshkey_puts(key, sigbuf)) != 0 ||

(r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,

sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), 0)) != 0 ||

@@ -1270,7 +1270,7 @@ server_input_global_request(int type, u_int32_t seq, void *ctxt)

} else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {

no_more_sessions = 1;

success = 1;

- } else if (strcmp(rtype, "hostkeys-prove@openssh.com") == 0) {

+ } else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {

success = server_input_hostkeys_prove(&resp);

}

if (want_reply) {

diff --git a/usr.bin/ssh/ssh.c b/usr.bin/ssh/ssh.c
index 108efd4bfa7..536f104d1a8 100644
--- a/usr.bin/ssh/ssh.c
+++ b/usr.bin/ssh/ssh.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: ssh.c,v 1.414 2015/01/20 23:14:00 deraadt Exp $ */

+/* $OpenBSD: ssh.c,v 1.415 2015/02/20 22:17:21 djm Exp $ */

* Author: Tatu Ylonen <ylo@cs.hut.fi>

@@ -1042,6 +1042,12 @@ main(int ac, char **av)

strcmp(options.proxy_command, "-") == 0 &&

options.proxy_use_fdpass)

fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");

+ if (options.control_persist &&

+ options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {

+ debug("UpdateHostKeys=ask is incompatible with ControlPersist; "

+ "disabling");

+ options.update_hostkeys = 0;

+ }

if (original_effective_uid != 0)

options.use_privileged_port = 0;

diff --git a/usr.bin/ssh/ssh_config.5 b/usr.bin/ssh/ssh_config.5
index fa59c518e87..140d0ba9815 100644
--- a/usr.bin/ssh/ssh_config.5
+++ b/usr.bin/ssh/ssh_config.5

@@ -33,8 +33,8 @@

.\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

.\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

.\"

-.\" $OpenBSD: ssh_config.5,v 1.204 2015/02/16 22:13:32 djm Exp $

-.Dd $Mdocdate: February 16 2015 $

+.\" $OpenBSD: ssh_config.5,v 1.205 2015/02/20 22:17:21 djm Exp $

+.Dd $Mdocdate: February 20 2015 $

.Dt SSH_CONFIG 5

.Os

.Sh NAME

@@ -1524,6 +1524,9 @@ If

is set to

.Dq ask ,

then the user is asked to confirm the modifications to the known_hosts file.

+Confirmation is currently incompatible with

+.Cm ControlPersist ,

+and will be disabled if it is enabled.

.Pp

Presently, only

.Xr sshd 8

diff --git a/usr.bin/ssh/sshd.c b/usr.bin/ssh/sshd.c
index 73621167d38..a7a183a6e93 100644
--- a/usr.bin/ssh/sshd.c
+++ b/usr.bin/ssh/sshd.c

@@ -1,4 +1,4 @@

-/* $OpenBSD: sshd.c,v 1.443 2015/02/16 22:30:03 djm Exp $ */

+/* $OpenBSD: sshd.c,v 1.444 2015/02/20 22:17:21 djm Exp $ */

* Author: Tatu Ylonen <ylo@cs.hut.fi>

@@ -905,7 +905,7 @@ notify_hostkeys(struct ssh *ssh)

free(fp);

if (nkeys == 0) {

packet_start(SSH2_MSG_GLOBAL_REQUEST);

- packet_put_cstring("hostkeys@openssh.com");

+ packet_put_cstring("hostkeys-00@openssh.com");

packet_put_char(0); /* want-reply */

}

sshbuf_reset(buf);