- dtucker@cvs.openbsd.org 2013/05/16 02:00:34

     [ssh_config sshconnect2.c packet.c readconf.h readconf.c clientloop.c
     ssh_config.5 packet.h]
     Add an optional second argument to RekeyLimit in the client to allow
     rekeying based on elapsed time in addition to amount of traffic.
     with djm@ jmc@, ok djm

1 files changed, 30 insertions, 3 deletions

diff --git a/packet.c b/packet.c
index 3c97383ec..dd9d26f5d 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.183 2013/04/19 01:06:50 djm Exp $ */
+/* $OpenBSD: packet.c,v 1.184 2013/05/16 02:00:34 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -58,6 +58,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <signal.h>
+#include <time.h>
 
 #include "xmalloc.h"
 #include "buffer.h"
@@ -165,9 +166,14 @@ struct session_state {
         Newkeys *newkeys[MODE_MAX];
         struct packet_state p_read, p_send;
 
+        /* Volume-based rekeying */
         u_int64_t max_blocks_in, max_blocks_out;
         u_int32_t rekey_limit;
 
+        /* Time-based rekeying */
+        time_t rekey_interval;  /* how often in seconds */
+        time_t rekey_time;      /* time of last rekeying */
+
         /* Session key for protocol v1 */
         u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
         u_int ssh1_keylen;
@@ -1009,6 +1015,7 @@ packet_send2(void)
         /* after a NEWKEYS message we can send the complete queue */
         if (type == SSH2_MSG_NEWKEYS) {
                 active_state->rekeying = 0;
+                active_state->rekey_time = time(NULL);
                 while ((p = TAILQ_FIRST(&active_state->outgoing))) {
                         type = p->type;
                         debug("dequeue packet: %u", type);
@@ -1933,13 +1940,33 @@ packet_need_rekeying(void)
             (active_state->max_blocks_out &&
                 (active_state->p_send.blocks > active_state->max_blocks_out)) ||
             (active_state->max_blocks_in &&
-                (active_state->p_read.blocks > active_state->max_blocks_in));
+                (active_state->p_read.blocks > active_state->max_blocks_in)) ||
+            (active_state->rekey_interval != 0 && active_state->rekey_time +
+                 active_state->rekey_interval <= time(NULL));
 }
 
 void
-packet_set_rekey_limit(u_int32_t bytes)
+packet_set_rekey_limits(u_int32_t bytes, time_t seconds)
 {
+        debug3("rekey after %lld bytes, %d seconds", (long long)bytes,
+            (int)seconds);
         active_state->rekey_limit = bytes;
+        active_state->rekey_interval = seconds;
+        /*
+         * We set the time here so that in post-auth privsep slave we count
+         * from the completion of the authentication.
+         */
+        active_state->rekey_time = time(NULL);
+}
+
+time_t
+packet_get_rekey_timeout(void)
+{
+        time_t seconds;
+
+        seconds = active_state->rekey_time + active_state->rekey_interval -
+            time(NULL);
+        return (seconds < 0 ? 0 : seconds);
 }
 
 void