diff -up openssh-6.6p1/channels.c.security openssh-6.6p1/channels.c

--- openssh-6.6p1/channels.c.security	2015-07-01 19:27:08.521162690 +0200

+++ openssh-6.6p1/channels.c	2015-07-01 19:27:08.597162521 +0200

@@ -151,6 +151,9 @@ static char *x11_saved_proto = NULL;

 static char *x11_saved_data = NULL;

 static u_int x11_saved_data_len = 0;

+/* Deadline after which all X11 connections are refused */

+static u_int x11_refuse_time;

+

 /*

  * Fake X11 authentication data.  This is what the server will be sending us;

  * we should replace any occurrences of this by the real data.

@@ -894,6 +897,13 @@ x11_open_helper(Buffer *b)

 	u_char *ucp;

 	u_int proto_len, data_len;

+	/* Is this being called after the refusal deadline? */

+	if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {

+		verbose("Rejected X11 connection after ForwardX11Timeout "

+		    "expired");

+		return -1;

+	}

+

 	/* Check if the fixed size part of the packet is in buffer. */

 	if (buffer_len(b) < 12)

 		return 0;

@@ -1457,6 +1467,12 @@ channel_set_reuseaddr(int fd)

 		error("setsockopt SO_REUSEADDR fd %d: %s", fd, strerror(errno));

 }

+void

+channel_set_x11_refuse_time(u_int refuse_time)

+{

+	x11_refuse_time = refuse_time;

+}

+

 /*

  * This socket is listening for connections to a forwarded TCP/IP port.

  */

diff -up openssh-6.6p1/channels.h.security openssh-6.6p1/channels.h

--- openssh-6.6p1/channels.h.security	2015-07-01 19:27:08.597162521 +0200

+++ openssh-6.6p1/channels.h	2015-07-01 19:43:32.900950560 +0200

@@ -279,6 +279,7 @@ int	 permitopen_port(const char *);

 /* x11 forwarding */

+void	 channel_set_x11_refuse_time(u_int);

 int	 x11_connect_display(void);

 int	 x11_create_display_inet(int, int, int, u_int *, int **);

 void     x11_input_open(int, u_int32_t, void *);

diff -up openssh-6.6p1/clientloop.c.security openssh-6.6p1/clientloop.c

--- openssh-6.6p1/clientloop.c.security	2015-07-01 19:27:08.540162648 +0200

+++ openssh-6.6p1/clientloop.c	2015-07-01 19:44:51.139761508 +0200

@@ -164,7 +164,7 @@ static int connection_in;	/* Connection

 static int connection_out;	/* Connection to server (output). */

 static int need_rekeying;	/* Set to non-zero if rekeying is requested. */

 static int session_closed;	/* In SSH2: login session closed. */

-static int x11_refuse_time;	/* If >0, refuse x11 opens after this time. */

+static u_int x11_refuse_time;	/* If >0, refuse x11 opens after this time. */

 static void client_init_dispatch(void);

 int	session_ident = -1;

@@ -302,7 +302,8 @@ client_x11_display_valid(const char *dis

 	return 1;

 }

-#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"

+#define SSH_X11_PROTO		"MIT-MAGIC-COOKIE-1"

+#define X11_TIMEOUT_SLACK	60

 void

 client_x11_get_proto(const char *display, const char *xauth_path,

     u_int trusted, u_int timeout, char **_proto, char **_data)

@@ -315,7 +316,7 @@ client_x11_get_proto(const char *display

 	int got_data = 0, generated = 0, do_unlink = 0, i;

 	char *xauthdir, *xauthfile;

 	struct stat st;

-	u_int now;

+	u_int now, x11_timeout_real;

 	xauthdir = xauthfile = NULL;

 	*_proto = proto;

@@ -348,6 +349,15 @@ client_x11_get_proto(const char *display

 			xauthdir = xmalloc(MAXPATHLEN);

 			xauthfile = xmalloc(MAXPATHLEN);

 			mktemp_proto(xauthdir, MAXPATHLEN);

+			/*

+			 * The authentication cookie should briefly outlive

+			 * ssh's willingness to forward X11 connections to

+			 * avoid nasty fail-open behaviour in the X server.

+			 */

+			if (timeout >= UINT_MAX - X11_TIMEOUT_SLACK)

+				x11_timeout_real = UINT_MAX;

+			else

+				x11_timeout_real = timeout + X11_TIMEOUT_SLACK;

 			if (mkdtemp(xauthdir) != NULL) {

 				do_unlink = 1;

 				snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",

@@ -355,17 +365,20 @@ client_x11_get_proto(const char *display

 				snprintf(cmd, sizeof(cmd),

 				    "%s -f %s generate %s " SSH_X11_PROTO

 				    " untrusted timeout %u 2>" _PATH_DEVNULL,

-				    xauth_path, xauthfile, display, timeout);

+				    xauth_path, xauthfile, display,

+				    x11_timeout_real);

 				debug2("x11_get_proto: %s", cmd);

-				if (system(cmd) == 0)

-					generated = 1;

 				if (x11_refuse_time == 0) {

 					now = monotime() + 1;

 					if (UINT_MAX - timeout < now)

 						x11_refuse_time = UINT_MAX;

 					else

 						x11_refuse_time = now + timeout;

+					channel_set_x11_refuse_time(

+					    x11_refuse_time);

 				}

+				if (system(cmd) == 0)

+					generated = 1;

 			}

 		}

@@ -1884,7 +1897,7 @@ client_request_x11(const char *request_t

 		    "malicious server.");

 		return NULL;

 	}

-	if (x11_refuse_time != 0 && monotime() >= x11_refuse_time) {

+	if (x11_refuse_time != 0 && (u_int)monotime() >= x11_refuse_time) {

 		verbose("Rejected X11 connection after ForwardX11Timeout "

 		    "expired");

 		return NULL;

diff -up openssh-6.6p1/ssh-agent.c.security openssh-6.6p1/ssh-agent.c

--- openssh-6.6p1/ssh-agent.c.security	2015-07-01 19:27:08.597162521 +0200

+++ openssh-6.6p1/ssh-agent.c	2015-07-01 19:42:35.691088800 +0200

@@ -64,6 +64,9 @@

 #include <time.h>

 #include <string.h>

 #include <unistd.h>

+#ifdef HAVE_UTIL_H

+#include <util.h>

+#endif

 #include "xmalloc.h"

 #include "ssh.h"

@@ -129,8 +130,12 @@ char socket_name[MAXPATHLEN];

 char socket_dir[MAXPATHLEN];

 /* locking */

+#define LOCK_SIZE	32

+#define LOCK_SALT_SIZE	16

+#define LOCK_ROUNDS	1

 int locked = 0;

-char *lock_passwd = NULL;

+char lock_passwd[LOCK_SIZE];

+char lock_salt[LOCK_SALT_SIZE];

 extern char *__progname;

@@ -548,22 +553,45 @@ send:

 static void

 process_lock_agent(SocketEntry *e, int lock)

 {

-	int success = 0;

-	char *passwd;

+	int success = 0, delay;

+	char *passwd, passwdhash[LOCK_SIZE];

+	static u_int fail_count = 0;

+	size_t pwlen;

 	passwd = buffer_get_string(&e->request, NULL);

-	if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {

-		locked = 0;

-		explicit_bzero(lock_passwd, strlen(lock_passwd));

-		free(lock_passwd);

-		lock_passwd = NULL;

-		success = 1;

+	pwlen = strlen(passwd);

+	if (pwlen == 0) {

+		debug("empty password not supported");

+	} else if (locked && !lock) {

+		if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),

+		    passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)

+			fatal("bcrypt_pbkdf");

+		if (timingsafe_bcmp(passwdhash, lock_passwd, LOCK_SIZE) == 0) {

+			debug("agent unlocked");

+			locked = 0;

+			fail_count = 0;

+			explicit_bzero(lock_passwd, sizeof(lock_passwd));

+			success = 1;

+		} else {

+			/* delay in 0.1s increments up to 10s */

+			if (fail_count < 100)

+				fail_count++;

+			delay = 100000 * fail_count;

+			debug("unlock failed, delaying %0.1lf seconds",

+			    (double)delay/1000000);

+			usleep(delay);

+		}

+		explicit_bzero(passwdhash, sizeof(passwdhash));

 	} else if (!locked && lock) {

+		debug("agent locked");

 		locked = 1;

-		lock_passwd = xstrdup(passwd);

+		arc4random_buf(lock_salt, sizeof(lock_salt));

+		if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),

+		    lock_passwd, sizeof(lock_passwd), LOCK_ROUNDS) < 0)

+			fatal("bcrypt_pbkdf");

 		success = 1;

 	}

-	explicit_bzero(passwd, strlen(passwd));

+	explicit_bzero(passwd, pwlen);

 	free(passwd);

 	buffer_put_int(&e->output, 1);