9 files changed, 135 insertions, 17 deletions

diff --git a/ChangeLog b/ChangeLog
index 85a5edcce..186c43247 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -28,6 +28,11 @@
      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
+   - dtucker@cvs.openbsd.org 2013/05/16 04:09:14
+     [sshd_config.5 servconf.c servconf.h packet.c serverloop.c monitor.c sshd_config
+     sshd.c] Add RekeyLimit to sshd with the same syntax as the client allowing
+     rekeying based on traffic volume or time.  ok djm@, help & ok jmc@ for the man
+     page.
 
 20130510
  - (dtucker) [configure.ac] Enable -Wsizeof-pointer-memaccess if the compiler
diff --git a/monitor.c b/monitor.c
index c0471a176..372c9d044 100644
--- a/monitor.c
+++ b/monitor.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: monitor.c,v 1.122 2013/03/07 19:27:25 markus Exp $ */
+/* $OpenBSD: monitor.c,v 1.123 2013/05/16 04:09:13 dtucker Exp $ */
 /*
  * Copyright 2002 Niels Provos <provos@citi.umich.edu>
  * Copyright 2002 Markus Friedl <markus@openbsd.org>
@@ -1810,6 +1810,10 @@ monitor_apply_keystate(struct monitor *pmonitor)
         if (options.compression)
                 mm_init_compression(pmonitor->m_zlib);
 
+        if (options.rekey_limit || options.rekey_interval)
+                packet_set_rekey_limits((u_int32_t)options.rekey_limit,
+                    (time_t)options.rekey_interval);
+
         /* Network I/O buffers */
         /* XXX inefficient for large buffers, need: buffer_init_from_string */
         buffer_clear(packet_get_input());
diff --git a/packet.c b/packet.c
index dd9d26f5d..a64bbae3c 100644
--- a/packet.c
+++ b/packet.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: packet.c,v 1.184 2013/05/16 02:00:34 dtucker Exp $ */
+/* $OpenBSD: packet.c,v 1.185 2013/05/16 04:09:13 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -1966,7 +1966,7 @@ packet_get_rekey_timeout(void)
 
         seconds = active_state->rekey_time + active_state->rekey_interval -
             time(NULL);
-        return (seconds < 0 ? 0 : seconds);
+        return (seconds <= 0 ? 1 : seconds);
 }
 
 void
diff --git a/servconf.c b/servconf.c
index b2a60fd6c..4e3026b83 100644
--- a/servconf.c
+++ b/servconf.c
@@ -1,5 +1,5 @@
 
-/* $OpenBSD: servconf.c,v 1.234 2013/02/06 00:20:42 dtucker Exp $ */
+/* $OpenBSD: servconf.c,v 1.235 2013/05/16 04:09:14 dtucker Exp $ */
 /*
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
  *                    All rights reserved
@@ -20,6 +20,7 @@
 #include <netinet/in_systm.h>
 #include <netinet/ip.h>
 
+#include <ctype.h>
 #include <netdb.h>
 #include <pwd.h>
 #include <stdio.h>
@@ -110,6 +111,8 @@ initialize_server_options(ServerOptions *options)
         options->permit_user_env = -1;
         options->use_login = -1;
         options->compression = -1;
+        options->rekey_limit = -1;
+        options->rekey_interval = -1;
         options->allow_tcp_forwarding = -1;
         options->allow_agent_forwarding = -1;
         options->num_allow_users = 0;
@@ -249,6 +252,10 @@ fill_default_server_options(ServerOptions *options)
                 options->use_login = 0;
         if (options->compression == -1)
                 options->compression = COMP_DELAYED;
+        if (options->rekey_limit == -1)
+                options->rekey_limit = 0;
+        if (options->rekey_interval == -1)
+                options->rekey_interval = 0;
         if (options->allow_tcp_forwarding == -1)
                 options->allow_tcp_forwarding = FORWARD_ALLOW;
         if (options->allow_agent_forwarding == -1)
@@ -320,7 +327,7 @@ typedef enum {
         sX11Forwarding, sX11DisplayOffset, sX11UseLocalhost,
         sStrictModes, sEmptyPasswd, sTCPKeepAlive,
         sPermitUserEnvironment, sUseLogin, sAllowTcpForwarding, sCompression,
-        sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
+        sRekeyLimit, sAllowUsers, sDenyUsers, sAllowGroups, sDenyGroups,
         sIgnoreUserKnownHosts, sCiphers, sMacs, sProtocol, sPidFile,
         sGatewayPorts, sPubkeyAuthentication, sXAuthLocation, sSubsystem,
         sMaxStartups, sMaxAuthTries, sMaxSessions,
@@ -422,6 +429,7 @@ static struct {
         { "permituserenvironment", sPermitUserEnvironment, SSHCFG_GLOBAL },
         { "uselogin", sUseLogin, SSHCFG_GLOBAL },
         { "compression", sCompression, SSHCFG_GLOBAL },
+        { "rekeylimit", sRekeyLimit, SSHCFG_ALL },
         { "tcpkeepalive", sTCPKeepAlive, SSHCFG_GLOBAL },
         { "keepalive", sTCPKeepAlive, SSHCFG_GLOBAL },  /* obsolete alias */
         { "allowtcpforwarding", sAllowTcpForwarding, SSHCFG_ALL },
@@ -800,14 +808,14 @@ process_server_config_line(ServerOptions *options, char *line,
     const char *filename, int linenum, int *activep,
     struct connection_info *connectinfo)
 {
-        char *cp, **charptr, *arg, *p;
-        int cmdline = 0, *intptr, value, value2, n;
+        char *cp, **charptr, *arg, *p, *endofnumber;
+        int cmdline = 0, *intptr, value, value2, n, port, scale;
         SyslogFacility *log_facility_ptr;
         LogLevel *log_level_ptr;
         ServerOpCodes opcode;
-        int port;
         u_int i, flags = 0;
         size_t len;
+        long long orig, val64;
         const struct multistate *multistate_ptr;
 
         cp = line;
@@ -1118,6 +1126,59 @@ process_server_config_line(ServerOptions *options, char *line,
                 multistate_ptr = multistate_compression;
                 goto parse_multistate;
 
+        case sRekeyLimit:
+                arg = strdelim(&cp);
+                if (!arg || *arg == '\0')
+                        fatal("%.200s line %d: Missing argument.", filename,
+                            linenum);
+                if (strcmp(arg, "default") == 0) {
+                        val64 = 0;
+                } else {
+                        if (arg[0] < '0' || arg[0] > '9')
+                                fatal("%.200s line %d: Bad number.", filename,
+                                    linenum);
+                        orig = val64 = strtoll(arg, &endofnumber, 10);
+                        if (arg == endofnumber)
+                                fatal("%.200s line %d: Bad number.", filename,
+                         linenum);
+                        switch (toupper(*endofnumber)) {
+                        case '\0':
+                                scale = 1;
+                                break;
+                        case 'K':
+                                scale = 1<<10;
+                                break;
+                        case 'M':
+                                scale = 1<<20;
+                                break;
+                        case 'G':
+                                scale = 1<<30;
+                                break;
+                        default:
+                                fatal("%.200s line %d: Invalid RekeyLimit "
+                                    "suffix", filename, linenum);
+                        }
+                        val64 *= scale;
+                        /* detect integer wrap and too-large limits */
+                        if ((val64 / scale) != orig || val64 > UINT_MAX)
+                                fatal("%.200s line %d: RekeyLimit too large",
+                                    filename, linenum);
+                        if (val64 != 0 && val64 < 16)
+                                fatal("%.200s line %d: RekeyLimit too small",
+                                    filename, linenum);
+                }
+                if (*activep && options->rekey_limit == -1)
+                        options->rekey_limit = (u_int32_t)val64;
+                if (cp != NULL) { /* optional rekey interval present */
+                        if (strcmp(cp, "none") == 0) {
+                                (void)strdelim(&cp);    /* discard */
+                                break;
+                        }
+                        intptr = &options->rekey_interval;
+                        goto parse_time;
+                }
+                break;
+
         case sGatewayPorts:
                 intptr = &options->gateway_ports;
                 multistate_ptr = multistate_gatewayports;
@@ -1718,6 +1779,8 @@ copy_set_server_options(ServerOptions *dst, ServerOptions *src, int preauth)
         M_CP_INTOPT(max_authtries);
         M_CP_INTOPT(ip_qos_interactive);
         M_CP_INTOPT(ip_qos_bulk);
+        M_CP_INTOPT(rekey_limit);
+        M_CP_INTOPT(rekey_interval);
 
         /* See comment in servconf.h */
         COPY_MATCH_STRING_OPTS();
@@ -2006,5 +2069,7 @@ dump_config(ServerOptions *o)
         printf("ipqos %s ", iptos2str(o->ip_qos_interactive));
         printf("%s\n", iptos2str(o->ip_qos_bulk));
 
+        printf("rekeylimit %lld %d\n", o->rekey_limit, o->rekey_interval);
+
         channel_print_adm_permitted_opens();
 }
diff --git a/servconf.h b/servconf.h
index 870c70982..fc051bd4b 100644
--- a/servconf.h
+++ b/servconf.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: servconf.h,v 1.107 2013/01/03 05:49:36 djm Exp $ */
+/* $OpenBSD: servconf.h,v 1.108 2013/05/16 04:09:14 dtucker Exp $ */
 
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
@@ -176,6 +176,9 @@ typedef struct {
         char   *authorized_keys_command;
         char   *authorized_keys_command_user;
 
+        int64_t rekey_limit;
+        int     rekey_interval;
+
         char   *version_addendum;       /* Appended to SSH banner */
 
         u_int   num_auth_methods;
diff --git a/serverloop.c b/serverloop.c
index e224bd08a..595899f61 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.164 2012/12/07 01:51:35 dtucker Exp $ */
+/* $OpenBSD: serverloop.c,v 1.165 2013/05/16 04:09:14 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -277,7 +277,7 @@ client_alive_check(void)
  */
 static void
 wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp, int *maxfdp,
-    u_int *nallocp, u_int max_time_milliseconds)
+    u_int *nallocp, u_int64_t max_time_milliseconds)
 {
         struct timeval tv, *tvp;
         int ret;
@@ -563,7 +563,7 @@ server_loop(pid_t pid, int fdin_arg, int fdout_arg, int fderr_arg)
         int wait_status;        /* Status returned by wait(). */
         pid_t wait_pid;         /* pid returned by wait(). */
         int waiting_termination = 0;    /* Have displayed waiting close message. */
-        u_int max_time_milliseconds;
+        u_int64_t max_time_milliseconds;
         u_int previous_stdout_buffer_bytes;
         u_int stdout_buffer_bytes;
         int type;
@@ -826,6 +826,7 @@ server_loop2(Authctxt *authctxt)
 {
         fd_set *readset = NULL, *writeset = NULL;
         int rekeying = 0, max_fd, nalloc = 0;
+        u_int64_t rekey_timeout_ms = 0;
 
         debug("Entering interactive session for SSH2.");
 
@@ -854,8 +855,13 @@ server_loop2(Authctxt *authctxt)
 
                 if (!rekeying && packet_not_very_much_data_to_write())
                         channel_output_poll();
+                if (options.rekey_interval > 0 && compat20 && !rekeying)
+                        rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
+                else
+                        rekey_timeout_ms = 0;
+
                 wait_until_can_do_something(&readset, &writeset, &max_fd,
-                    &nalloc, 0);
+                    &nalloc, rekey_timeout_ms);
 
                 if (received_sigterm) {
                         logit("Exiting on signal %d", (int)received_sigterm);
diff --git a/sshd.c b/sshd.c
index a0f5c0d26..9a8e7b8ba 100644
--- a/sshd.c
+++ b/sshd.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: sshd.c,v 1.399 2013/04/07 02:10:33 dtucker Exp $ */
+/* $OpenBSD: sshd.c,v 1.400 2013/05/16 04:09:14 dtucker Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -2364,6 +2364,10 @@ do_ssh2_kex(void)
         if (options.kex_algorithms != NULL)
                 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
 
+        if (options.rekey_limit || options.rekey_interval)
+                packet_set_rekey_limits((u_int32_t)options.rekey_limit,
+                    (time_t)options.rekey_interval);
+
         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
 
         /* start key exchange */
diff --git a/sshd_config b/sshd_config
index 9cd2fddce..b786361d1 100644
--- a/sshd_config
+++ b/sshd_config
@@ -1,4 +1,4 @@
-#       $OpenBSD: sshd_config,v 1.89 2013/02/06 00:20:42 dtucker Exp $
+#       $OpenBSD: sshd_config,v 1.90 2013/05/16 04:09:14 dtucker Exp $
 
 # This is the sshd server system-wide configuration file.  See
 # sshd_config(5) for more information.
@@ -29,6 +29,9 @@
 #KeyRegenerationInterval 1h
 #ServerKeyBits 1024
 
+# Ciphers and keying
+#RekeyLimit default none
+
 # Logging
 # obsoletes QuietMode and FascistLogging
 #SyslogFacility AUTH
diff --git a/sshd_config.5 b/sshd_config.5
index 590fb4088..9e0b3a5c0 100644
--- a/sshd_config.5
+++ b/sshd_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: sshd_config.5,v 1.158 2013/04/19 01:00:10 djm Exp $
-.Dd $Mdocdate: April 19 2013 $
+.\" $OpenBSD: sshd_config.5,v 1.159 2013/05/16 04:09:14 dtucker Exp $
+.Dd $Mdocdate: May 16 2013 $
 .Dt SSHD_CONFIG 5
 .Os
 .Sh NAME
@@ -814,6 +814,7 @@ Available keywords are
 .Cm PermitRootLogin ,
 .Cm PermitTunnel ,
 .Cm PubkeyAuthentication ,
+.Cm RekeyLimit ,
 .Cm RhostsRSAAuthentication ,
 .Cm RSAAuthentication ,
 .Cm X11DisplayOffset ,
@@ -1008,6 +1009,33 @@ Specifies whether public key authentication is allowed.
 The default is
 .Dq yes .
 Note that this option applies to protocol version 2 only.
+.It Cm RekeyLimit
+Specifies the maximum amount of data that may be transmitted before the
+session key is renegotiated, optionally followed a maximum amount of
+time that may pass before the session key is renegotiated.
+The first argument is specified in bytes and may have a suffix of
+.Sq K ,
+.Sq M ,
+or
+.Sq G
+to indicate Kilobytes, Megabytes, or Gigabytes, respectively.
+The default is between
+.Sq 1G
+and
+.Sq 4G ,
+depending on the cipher.
+The optional second value is specified in seconds and may use any of the
+units documented in the
+.Sx TIME FORMATS
+section of
+.Xr sshd_config 5 .
+The default value for
+.Cm RekeyLimit
+is
+.Dq default none ,
+which means that rekeying is performed after the cipher's default amount
+of data has been sent or received and no time based rekeying is done.
+This option applies to protocol version 2 only.
 .It Cm RevokedKeys
 Specifies revoked public keys.
 Keys listed in this file will be refused for public key authentication.