Fix keyboard-interactive authentication for ssh1. The problem was twofold:

 - The PAM kbdint device sometimes doesn't know authentication succeeded
   until you re-query it.  The ssh1 kbdint code would never re-query the
   device, so authentication would always fail.  This patch has been
   submitted to the OpenSSH developers.

 - The monitor code for PAM sometimes forgot to tell the monitor that
   authentication had succeeded.  This caused the monitor to veto the
   privsep child's decision to allow the connection.

These patches have been tested with OpenSSH clients on -STABLE, NetBSD and
Linux, and with ssh.com's ssh1 on Solaris.

Sponsored by:	DARPA, NAI Labs

2 files changed, 21 insertions, 0 deletions

diff --git a/crypto/openssh/auth-chall.c b/crypto/openssh/auth-chall.c
index 45e0c34..b9c2efd 100644
--- a/crypto/openssh/auth-chall.c
+++ b/crypto/openssh/auth-chall.c
@@ -24,6 +24,7 @@
 
 #include "includes.h"
 RCSID("$OpenBSD: auth-chall.c,v 1.8 2001/05/18 14:13:28 markus Exp $");
+RCSID("$FreeBSD$");
 
 #include "auth.h"
 #include "log.h"
@@ -76,6 +77,24 @@ verify_response(Authctxt *authctxt, const char *response)
 		return 0;
 	resp[0] = (char *)response;
 	res = device->respond(authctxt->kbdintctxt, 1, resp);
+	if (res == 1) {
+		/* postponed - send a null query just in case */
+		char *name, *info, **prompts;
+		u_int i, numprompts, *echo_on;
+
+		res = device->query(authctxt->kbdintctxt, &name, &info,
+		    &numprompts, &prompts, &echo_on);
+		if (res == 0) {
+			for (i = 0; i < numprompts; i++)
+				xfree(prompts[i]);
+			xfree(prompts);
+			xfree(name);
+			xfree(echo_on);
+			xfree(info);
+		}
+		/* if we received more prompts, we're screwed */
+		res = (numprompts != 0);
+	}
 	device->free_ctx(authctxt->kbdintctxt);
 	authctxt->kbdintctxt = NULL;
 	return res ? 0 : 1;
diff --git a/crypto/openssh/monitor.c b/crypto/openssh/monitor.c
index 5a597ef..b75c285 100644
--- a/crypto/openssh/monitor.c
+++ b/crypto/openssh/monitor.c
@@ -797,6 +797,8 @@ mm_answer_pam_query(int socket, Buffer *m)
 	debug3("%s", __func__);
 	pam_authok = NULL;
 	ret = (pam_device.query)(pam_ctxt, &name, &info, &num, &prompts, &echo_on);
+	if (ret == 0 && num == 0)
+		pam_authok = pam_ctxt;
 	if (num > 1 || name == NULL || info == NULL)
 		ret = -1;
 	buffer_clear(m);