Colours now work properly, including 256-colour stuff.
[u/mdw/putty] / ssh.c
diff --git a/ssh.c b/ssh.c
index e619b59..4a09a64 100644 (file)
--- a/ssh.c
+++ b/ssh.c
  */
 #define SSH2_PKTCTX_DHGROUP          0x0001
 #define SSH2_PKTCTX_DHGEX            0x0002
+#define SSH2_PKTCTX_KEX_MASK         0x000F
 #define SSH2_PKTCTX_PUBLICKEY        0x0010
 #define SSH2_PKTCTX_PASSWORD         0x0020
 #define SSH2_PKTCTX_KBDINTER         0x0040
@@ -162,7 +163,7 @@ static const char *const ssh2_disconnect_reasons[] = {
 #define BUG_CHOKES_ON_RSA                        8
 #define BUG_SSH2_RSA_PADDING                    16
 #define BUG_SSH2_DERIVEKEY                       32
-/* 64 was BUG_SSH2_DH_GEX, now spare */
+#define BUG_SSH2_REKEY                           64
 #define BUG_SSH2_PK_SESSIONID                   128
 
 #define translate(x) if (type == x) return #x
@@ -359,6 +360,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 #define SSH1_BUFFER_LIMIT 32768
 #define SSH_MAX_BACKLOG 32768
 #define OUR_V2_WINSIZE 16384
+#define OUR_V2_MAXPKT 0x4000UL
 
 const static struct ssh_signkey *hostkey_algs[] = { &ssh_rsa, &ssh_dss };
 
@@ -516,18 +518,22 @@ struct ssh_rportfwd {
  * it.
  */
 struct ssh_portfwd {
-    int keep;
+    enum { DESTROY, KEEP, CREATE } status;
     int type;
     unsigned sport, dport;
     char *saddr, *daddr;
+    char *sserv, *dserv;
     struct ssh_rportfwd *remote;
+    int addressfamily;
     void *local;
 };
 #define free_portfwd(pf) ( \
-    ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr)) : (void)0 ), sfree(pf) )
+    ((pf) ? (sfree((pf)->saddr), sfree((pf)->daddr), \
+            sfree((pf)->sserv), sfree((pf)->dserv)) : (void)0 ), sfree(pf) )
 
 struct Packet {
     long length;
+    long forcepad; /* Force padding to at least this length */
     int type;
     unsigned long sequence;
     unsigned char *data;
@@ -544,9 +550,9 @@ struct Packet {
     struct logblank_t *blanks;
 };
 
-static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
                          struct Packet *pktin);
-static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
                          struct Packet *pktin);
 static void ssh1_protocol_setup(Ssh ssh);
 static void ssh2_protocol_setup(Ssh ssh);
@@ -557,12 +563,12 @@ static void ssh2_add_channel_data(struct ssh_channel *c, char *buf, int len);
 static void ssh_throttle_all(Ssh ssh, int enable, int bufsize);
 static void ssh2_set_window(struct ssh_channel *c, unsigned newwin);
 static int ssh_sendbuffer(void *handle);
-static void ssh_do_close(Ssh ssh);
+static int ssh_do_close(Ssh ssh, int notify_exit);
 static unsigned long ssh_pkt_getuint32(struct Packet *pkt);
 static int ssh2_pkt_getbool(struct Packet *pkt);
 static void ssh_pkt_getstring(struct Packet *pkt, char **p, int *length);
 static void ssh2_timer(void *ctx, long now);
-static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
+static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
                             struct Packet *pktin);
 
 struct rdpkt1_state_tag {
@@ -638,6 +644,7 @@ struct ssh_tag {
     tree234 *channels;                /* indexed by local id */
     struct ssh_channel *mainchan;      /* primary session channel */
     int exitcode;
+    int close_expected;
 
     tree234 *rportfwds, *portfwds;
 
@@ -682,7 +689,7 @@ struct ssh_tag {
     int overall_bufsize;
     int throttled_all;
     int v1_stdout_throttling;
-    int v2_outgoing_sequence;
+    unsigned long v2_outgoing_sequence;
 
     int ssh1_rdpkt_crstate;
     int ssh2_rdpkt_crstate;
@@ -704,7 +711,7 @@ struct ssh_tag {
     /* ssh1 and ssh2 use this for different things, but both use it */
     int protocol_initial_phase_done;
 
-    void (*protocol) (Ssh ssh, unsigned char *in, int inlen,
+    void (*protocol) (Ssh ssh, void *vin, int inlen,
                      struct Packet *pkt);
     struct Packet *(*s_rdpkt) (Ssh ssh, unsigned char **data, int *datalen);
 
@@ -746,7 +753,8 @@ struct ssh_tag {
     unsigned long incoming_data_size, outgoing_data_size, deferred_data_size;
     unsigned long max_data_size;
     int kex_in_progress;
-    long next_rekey;
+    long next_rekey, last_rekey;
+    char *deferred_rekey_reason;    /* points to STATIC string; don't free */
 };
 
 #define logevent(s) logevent(ssh->frontend, s)
@@ -767,7 +775,7 @@ static void logeventf(Ssh ssh, const char *fmt, ...)
 #define bombout(msg) \
     do { \
         char *text = dupprintf msg; \
-       ssh_do_close(ssh); \
+       ssh_do_close(ssh, FALSE); \
         logevent(text); \
         connection_fatal(ssh->frontend, "%s", text); \
         sfree(text); \
@@ -863,6 +871,10 @@ static int ssh_portcmp(void *av, void *bv)
        return +1;
     if (a->type < b->type)
        return -1;
+    if (a->addressfamily > b->addressfamily)
+       return +1;
+    if (a->addressfamily < b->addressfamily)
+       return -1;
     if ( (i = nullstrcmp(a->saddr, b->saddr)) != 0)
        return i < 0 ? -1 : +1;
     if (a->sport > b->sport)
@@ -1561,6 +1573,7 @@ static struct Packet *ssh2_pkt_init(int pkt_type)
 {
     struct Packet *pkt = ssh_new_packet();
     pkt->length = 5;
+    pkt->forcepad = 0;
     ssh2_pkt_addbyte(pkt, (unsigned char) pkt_type);
     return pkt;
 }
@@ -1657,12 +1670,17 @@ static int ssh2_pkt_construct(Ssh ssh, struct Packet *pkt)
     /*
      * Add padding. At least four bytes, and must also bring total
      * length (minus MAC) up to a multiple of the block size.
+     * If pkt->forcepad is set, make sure the packet is at least that size
+     * after padding.
      */
     cipherblk = ssh->cscipher ? ssh->cscipher->blksize : 8;  /* block size */
     cipherblk = cipherblk < 8 ? 8 : cipherblk; /* or 8 if blksize < 8 */
     padding = 4;
+    if (pkt->length + padding < pkt->forcepad)
+       padding = pkt->forcepad - pkt->length;
     padding +=
        (cipherblk - (pkt->length + padding) % cipherblk) % cipherblk;
+    assert(padding <= 255);
     maclen = ssh->csmac ? ssh->csmac->len : 0;
     ssh2_pkt_ensure(pkt, pkt->length + padding + maclen);
     pkt->data[4] = padding;
@@ -1730,8 +1748,7 @@ static void ssh2_pkt_send_noqueue(Ssh ssh, struct Packet *pkt)
     if (!ssh->kex_in_progress &&
        ssh->max_data_size != 0 &&
        ssh->outgoing_data_size > ssh->max_data_size)
-       do_ssh2_transport(ssh, "Initiating key re-exchange "
-                         "(too much data sent)", -1, NULL);
+       do_ssh2_transport(ssh, "too much data sent", -1, NULL);
 
     ssh_free_packet(pkt);
 }
@@ -1781,6 +1798,7 @@ static void ssh2_pkt_send(Ssh ssh, struct Packet *pkt)
        ssh2_pkt_send_noqueue(ssh, pkt);
 }
 
+#if 0 /* disused */
 /*
  * Either queue or defer a packet, depending on whether queueing is
  * set.
@@ -1792,6 +1810,7 @@ static void ssh2_pkt_defer(Ssh ssh, struct Packet *pkt)
     else
        ssh2_pkt_defer_noqueue(ssh, pkt);
 }
+#endif
 
 /*
  * Send the whole deferred data block constructed by
@@ -1821,8 +1840,7 @@ static void ssh_pkt_defersend(Ssh ssh)
     if (!ssh->kex_in_progress &&
        ssh->max_data_size != 0 &&
        ssh->outgoing_data_size > ssh->max_data_size)
-       do_ssh2_transport(ssh, "Initiating key re-exchange "
-                         "(too much data sent)", -1, NULL);
+       do_ssh2_transport(ssh, "too much data sent", -1, NULL);
     ssh->deferred_data_size = 0;
 }
 
@@ -2129,6 +2147,19 @@ static void ssh_detect_bugs(Ssh ssh, char *vstring)
        ssh->remote_bugs |= BUG_SSH2_PK_SESSIONID;
        logevent("We believe remote version has SSH2 public-key-session-ID bug");
     }
+
+    if (ssh->cfg.sshbug_rekey2 == FORCE_ON ||
+       (ssh->cfg.sshbug_rekey2 == AUTO &&
+        (wc_match("OpenSSH_2.[0-4]*", imp) ||
+         wc_match("OpenSSH_2.5.[0-3]*", imp) ||
+         wc_match("Sun_SSH_1.0", imp) ||
+         wc_match("Sun_SSH_1.0.1", imp)))) {
+       /*
+        * These versions have the SSH2 rekey bug.
+        */
+       ssh->remote_bugs |= BUG_SSH2_REKEY;
+       logevent("We believe remote version has SSH2 rekey bug");
+    }
 }
 
 /*
@@ -2348,16 +2379,19 @@ static void ssh_gotdata(Ssh ssh, unsigned char *data, int datalen)
     crFinishV;
 }
 
-static void ssh_do_close(Ssh ssh)
+static int ssh_do_close(Ssh ssh, int notify_exit)
 {
-    int i;
+    int i, ret = 0;
     struct ssh_channel *c;
 
     ssh->state = SSH_STATE_CLOSED;
     if (ssh->s) {
         sk_close(ssh->s);
         ssh->s = NULL;
-       notify_remote_exit(ssh->frontend);
+        if (notify_exit)
+            notify_remote_exit(ssh->frontend);
+        else
+            ret = 1;
     }
     /*
      * Now we must shut down any port and X forwardings going
@@ -2379,20 +2413,45 @@ static void ssh_do_close(Ssh ssh)
            sfree(c);
        }
     }
+
+    return ret;
+}
+
+static void ssh_log(Plug plug, int type, SockAddr addr, int port,
+                   const char *error_msg, int error_code)
+{
+    Ssh ssh = (Ssh) plug;
+    char addrbuf[256], *msg;
+
+    sk_getaddr(addr, addrbuf, lenof(addrbuf));
+
+    if (type == 0)
+       msg = dupprintf("Connecting to %s port %d", addrbuf, port);
+    else
+       msg = dupprintf("Failed to connect to %s: %s", addrbuf, error_msg);
+
+    logevent(msg);
 }
 
 static int ssh_closing(Plug plug, const char *error_msg, int error_code,
                       int calling_back)
 {
     Ssh ssh = (Ssh) plug;
-    ssh_do_close(ssh);
+    int need_notify = ssh_do_close(ssh, FALSE);
+
+    if (!error_msg && !ssh->close_expected) {
+        error_msg = "Server unexpectedly closed network connection";
+    }
+
     if (error_msg) {
        /* A socket error has occurred. */
        logevent(error_msg);
        connection_fatal(ssh->frontend, "%s", error_msg);
     } else {
-       /* Otherwise, the remote side closed the connection normally. */
+        logevent("Server closed network connection");
     }
+    if (need_notify)
+        notify_remote_exit(ssh->frontend);
     return 0;
 }
 
@@ -2401,7 +2460,7 @@ static int ssh_receive(Plug plug, int urgent, char *data, int len)
     Ssh ssh = (Ssh) plug;
     ssh_gotdata(ssh, (unsigned char *)data, len);
     if (ssh->state == SSH_STATE_CLOSED) {
-       ssh_do_close(ssh);
+       ssh_do_close(ssh, TRUE);
        return 0;
     }
     return 1;
@@ -2428,6 +2487,7 @@ static const char *connect_to_host(Ssh ssh, char *host, int port,
                                   char **realhost, int nodelay, int keepalive)
 {
     static const struct plug_function_table fn_table = {
+       ssh_log,
        ssh_closing,
        ssh_receive,
        ssh_sent,
@@ -2449,8 +2509,11 @@ static const char *connect_to_host(Ssh ssh, char *host, int port,
     /*
      * Try to find host.
      */
-    logeventf(ssh, "Looking up host \"%s\"", host);
-    addr = name_lookup(host, port, realhost, &ssh->cfg);
+    logeventf(ssh, "Looking up host \"%s\"%s", host,
+             (ssh->cfg.addressfamily == ADDRTYPE_IPV4 ? " (IPv4)" :
+              (ssh->cfg.addressfamily == ADDRTYPE_IPV6 ? " (IPv6)" : "")));
+    addr = name_lookup(host, port, realhost, &ssh->cfg,
+                      ssh->cfg.addressfamily);
     if ((err = sk_addr_error(addr)) != NULL) {
        sk_addr_free(addr);
        return err;
@@ -2459,11 +2522,6 @@ static const char *connect_to_host(Ssh ssh, char *host, int port,
     /*
      * Open socket.
      */
-    {
-       char addrbuf[100];
-       sk_getaddr(addr, addrbuf, 100);
-       logeventf(ssh, "Connecting to %s port %d", addrbuf, port);
-    }
     ssh->fn = &fn_table;
     ssh->s = new_connection(addr, *realhost, port,
                            0, 1, nodelay, keepalive, (Plug) ssh, &ssh->cfg);
@@ -2823,8 +2881,11 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
        }
 
        /* Warn about chosen cipher if necessary. */
-       if (warn)
+       if (warn) {
+            sk_set_frozen(ssh->s, 1);
            askalg(ssh->frontend, "cipher", cipher_string);
+            sk_set_frozen(ssh->s, 0);
+        }
     }
 
     switch (s->cipher_type) {
@@ -2896,6 +2957,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
                     * Terminate.
                     */
                    logevent("No username provided. Abandoning session.");
+                   ssh->close_expected = TRUE;
                     ssh_closing((Plug)ssh, NULL, 0, 0);
                    crStop(1);
                }
@@ -3244,6 +3306,7 @@ static int do_ssh1_login(Ssh ssh, unsigned char *in, int inlen,
                            PKT_END);
                logevent("Unable to authenticate");
                connection_fatal(ssh->frontend, "Unable to authenticate");
+               ssh->close_expected = TRUE;
                 ssh_closing((Plug)ssh, NULL, 0, 0);
                crStop(1);
            }
@@ -3666,32 +3729,45 @@ static void ssh_rportfwd_succfail(Ssh ssh, struct Packet *pktin, void *ctx)
 
 static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
 {
-    char type;
-    int n;
-    int sport,dport,sserv,dserv;
-    char sports[256], dports[256], saddr[256], host[256];
-    const char *portfwd_strptr;
-
-    portfwd_strptr = cfg->portfwd;
+    const char *portfwd_strptr = cfg->portfwd;
+    struct ssh_portfwd *epf;
+    int i;
 
     if (!ssh->portfwds) {
        ssh->portfwds = newtree234(ssh_portcmp);
     } else {
        /*
         * Go through the existing port forwardings and tag them
-        * with keep==FALSE. Any that we want to keep will be
-        * re-enabled as we go through the configuration and find
-        * out which bits are the same as they were before.
+        * with status==DESTROY. Any that we want to keep will be
+        * re-enabled (status==KEEP) as we go through the
+        * configuration and find out which bits are the same as
+        * they were before.
         */
        struct ssh_portfwd *epf;
        int i;
        for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
-           epf->keep = FALSE;
+           epf->status = DESTROY;
     }
 
     while (*portfwd_strptr) {
-       type = *portfwd_strptr++;
+       char address_family, type;
+       int sport,dport,sserv,dserv;
+       char sports[256], dports[256], saddr[256], host[256];
+       int n;
+
+       address_family = 'A';
+       type = 'L';
+       if (*portfwd_strptr == 'A' ||
+           *portfwd_strptr == '4' ||
+           *portfwd_strptr == '6')
+           address_family = *portfwd_strptr++;
+       if (*portfwd_strptr == 'L' ||
+           *portfwd_strptr == 'R' ||
+           *portfwd_strptr == 'D')
+           type = *portfwd_strptr++;
+
        saddr[0] = '\0';
+
        n = 0;
        while (*portfwd_strptr && *portfwd_strptr != '\t') {
            if (*portfwd_strptr == ':') {
@@ -3759,61 +3835,152 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
        if (sport && dport) {
            /* Set up a description of the source port. */
            struct ssh_portfwd *pfrec, *epfrec;
-           char *sportdesc;
-           sportdesc = dupprintf("%.*s%.*s%.*s%.*s%d%.*s",
-                                 (int)(*saddr?strlen(saddr):0), *saddr?saddr:NULL,
-                                 (int)(*saddr?1:0), ":",
-                                 (int)(sserv ? strlen(sports) : 0), sports,
-                                 sserv, "(", sport, sserv, ")");
 
            pfrec = snew(struct ssh_portfwd);
            pfrec->type = type;
            pfrec->saddr = *saddr ? dupstr(saddr) : NULL;
+           pfrec->sserv = sserv ? dupstr(sports) : NULL;
            pfrec->sport = sport;
-           pfrec->daddr = dupstr(host);
+           pfrec->daddr = *host ? dupstr(host) : NULL;
+           pfrec->dserv = dserv ? dupstr(dports) : NULL;
            pfrec->dport = dport;
            pfrec->local = NULL;
            pfrec->remote = NULL;
+           pfrec->addressfamily = (address_family == '4' ? ADDRTYPE_IPV4 :
+                                   address_family == '6' ? ADDRTYPE_IPV6 :
+                                   ADDRTYPE_UNSPEC);
 
            epfrec = add234(ssh->portfwds, pfrec);
            if (epfrec != pfrec) {
                /*
                 * We already have a port forwarding with precisely
                 * these parameters. Hence, no need to do anything;
-                * simply tag the existing one as `keep'.
+                * simply tag the existing one as KEEP.
                 */
-               epfrec->keep = TRUE;
+               epfrec->status = KEEP;
                free_portfwd(pfrec);
-           } else if (type == 'L') {
-               /* Verbose description of the destination port */
-               char *dportdesc = dupprintf("%s:%.*s%.*s%d%.*s",
-                                           host,
-                                           (int)(dserv ? strlen(dports) : 0), dports,
-                                           dserv, "(", dport, dserv, ")");
-               const char *err = pfd_addforward(host, dport,
-                                                *saddr ? saddr : NULL,
-                                                sport, ssh, &ssh->cfg,
-                                                &pfrec->local);
-               if (err) {
-                   logeventf(ssh, "Local port %s forward to %s"
-                             " failed: %s", sportdesc, dportdesc, err);
+           } else {
+               pfrec->status = CREATE;
+           }
+       }
+    }
+
+    /*
+     * Now go through and destroy any port forwardings which were
+     * not re-enabled.
+     */
+    for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
+       if (epf->status == DESTROY) {
+           char *message;
+
+           message = dupprintf("%s port forwarding from %s%s%d",
+                               epf->type == 'L' ? "local" :
+                               epf->type == 'R' ? "remote" : "dynamic",
+                               epf->saddr ? epf->saddr : "",
+                               epf->saddr ? ":" : "",
+                               epf->sport);
+
+           if (epf->type != 'D') {
+               char *msg2 = dupprintf("%s to %s:%d", message,
+                                      epf->daddr, epf->dport);
+               sfree(message);
+               message = msg2;
+           }
+
+           logeventf(ssh, "Cancelling %s", message);
+           sfree(message);
+
+           if (epf->remote) {
+               struct ssh_rportfwd *rpf = epf->remote;
+               struct Packet *pktout;
+
+               /*
+                * Cancel the port forwarding at the server
+                * end.
+                */
+               if (ssh->version == 1) {
+                   /*
+                    * We cannot cancel listening ports on the
+                    * server side in SSH1! There's no message
+                    * to support it. Instead, we simply remove
+                    * the rportfwd record from the local end
+                    * so that any connections the server tries
+                    * to make on it are rejected.
+                    */
                } else {
-                   logeventf(ssh, "Local port %s forwarding to %s",
-                             sportdesc, dportdesc);
+                   pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
+                   ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
+                   ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
+                   if (epf->saddr) {
+                       ssh2_pkt_addstring(pktout, epf->saddr);
+                   } else if (ssh->cfg.rport_acceptall) {
+                       ssh2_pkt_addstring(pktout, "0.0.0.0");
+                   } else {
+                       ssh2_pkt_addstring(pktout, "127.0.0.1");
+                   }
+                   ssh2_pkt_adduint32(pktout, epf->sport);
+                   ssh2_pkt_send(ssh, pktout);
                }
-               sfree(dportdesc);
-           } else if (type == 'D') {
+
+               del234(ssh->rportfwds, rpf);
+               free_rportfwd(rpf);
+           } else if (epf->local) {
+               pfd_terminate(epf->local);
+           }
+
+           delpos234(ssh->portfwds, i);
+           free_portfwd(epf);
+           i--;                       /* so we don't skip one in the list */
+       }
+
+    /*
+     * And finally, set up any new port forwardings (status==CREATE).
+     */
+    for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
+       if (epf->status == CREATE) {
+           char *sportdesc, *dportdesc;
+           sportdesc = dupprintf("%s%s%s%s%d%s",
+                                 epf->saddr ? epf->saddr : "",
+                                 epf->saddr ? ":" : "",
+                                 epf->sserv ? epf->sserv : "",
+                                 epf->sserv ? "(" : "",
+                                 epf->sport,
+                                 epf->sserv ? ")" : "");
+           if (epf->type == 'D') {
+               dportdesc = NULL;
+           } else {
+               dportdesc = dupprintf("%s:%s%s%d%s",
+                                     epf->daddr,
+                                     epf->dserv ? epf->dserv : "",
+                                     epf->dserv ? "(" : "",
+                                     epf->dport,
+                                     epf->dserv ? ")" : "");
+           }
+
+           if (epf->type == 'L') {
+               const char *err = pfd_addforward(epf->daddr, epf->dport,
+                                                epf->saddr, epf->sport,
+                                                ssh, &ssh->cfg,
+                                                &epf->local,
+                                                epf->addressfamily);
+
+               logeventf(ssh, "Local %sport %s forwarding to %s%s%s",
+                         epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
+                         epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
+                         sportdesc, dportdesc,
+                         err ? " failed: " : "", err ? err : "");
+           } else if (epf->type == 'D') {
                const char *err = pfd_addforward(NULL, -1,
-                                                *saddr ? saddr : NULL,
-                                                sport, ssh, &ssh->cfg,
-                                                &pfrec->local);
-               if (err) {
-                   logeventf(ssh, "Local port %s SOCKS dynamic forward"
-                             " setup failed: %s", sportdesc, err);
-               } else {
-                   logeventf(ssh, "Local port %s doing SOCKS"
-                             " dynamic forwarding", sportdesc);
-               }
+                                                epf->saddr, epf->sport,
+                                                ssh, &ssh->cfg,
+                                                &epf->local,
+                                                epf->addressfamily);
+
+               logeventf(ssh, "Local %sport %s SOCKS dynamic forwarding%s%s",
+                         epf->addressfamily == ADDRTYPE_IPV4 ? "IPv4 " :
+                         epf->addressfamily == ADDRTYPE_IPV6 ? "IPv6 " : "",
+                         sportdesc,
+                         err ? " failed: " : "", err ? err : "");
            } else {
                struct ssh_rportfwd *pf;
 
@@ -3828,30 +3995,28 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
                }
 
                pf = snew(struct ssh_rportfwd);
-               strcpy(pf->dhost, host);
-               pf->dport = dport;
-               pf->sport = sport;
+               strncpy(pf->dhost, epf->daddr, lenof(pf->dhost)-1);
+               pf->dhost[lenof(pf->dhost)-1] = '\0';
+               pf->dport = epf->dport;
+               pf->sport = epf->sport;
                if (add234(ssh->rportfwds, pf) != pf) {
                    logeventf(ssh, "Duplicate remote port forwarding to %s:%d",
-                             host, dport);
+                             epf->daddr, epf->dport);
                    sfree(pf);
                } else {
                    logeventf(ssh, "Requesting remote port %s"
-                             " forward to %s:%.*s%.*s%d%.*s",
-                             sportdesc, host,
-                             (int)(dserv ? strlen(dports) : 0), dports,
-                             dserv, "(", dport, dserv, ")");
+                             " forward to %s", sportdesc, dportdesc);
 
                    pf->sportdesc = sportdesc;
                    sportdesc = NULL;
-                   pfrec->remote = pf;
-                   pf->pfrec = pfrec;
+                   epf->remote = pf;
+                   pf->pfrec = epf;
 
                    if (ssh->version == 1) {
                        send_packet(ssh, SSH1_CMSG_PORT_FORWARD_REQUEST,
-                                   PKT_INT, sport,
-                                   PKT_STR, host,
-                                   PKT_INT, dport,
+                                   PKT_INT, epf->sport,
+                                   PKT_STR, epf->daddr,
+                                   PKT_INT, epf->dport,
                                    PKT_END);
                        ssh_queue_handler(ssh, SSH1_SMSG_SUCCESS,
                                          SSH1_SMSG_FAILURE,
@@ -3861,14 +4026,14 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
                        pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
                        ssh2_pkt_addstring(pktout, "tcpip-forward");
                        ssh2_pkt_addbool(pktout, 1);/* want reply */
-                       if (*saddr) {
-                           ssh2_pkt_addstring(pktout, saddr);
+                       if (epf->saddr) {
+                           ssh2_pkt_addstring(pktout, epf->saddr);
                        } else if (ssh->cfg.rport_acceptall) {
                            ssh2_pkt_addstring(pktout, "0.0.0.0");
                        } else {
                            ssh2_pkt_addstring(pktout, "127.0.0.1");
                        }
-                       ssh2_pkt_adduint32(pktout, sport);
+                       ssh2_pkt_adduint32(pktout, epf->sport);
                        ssh2_pkt_send(ssh, pktout);
 
                        ssh_queue_handler(ssh, SSH2_MSG_REQUEST_SUCCESS,
@@ -3878,80 +4043,8 @@ static void ssh_setup_portfwd(Ssh ssh, const Config *cfg)
                }
            }
            sfree(sportdesc);
+           sfree(dportdesc);
        }
-    }
-
-    /*
-     * Now go through and destroy any port forwardings which were
-     * not re-enabled.
-     */
-    {
-       struct ssh_portfwd *epf;
-       int i;
-       for (i = 0; (epf = index234(ssh->portfwds, i)) != NULL; i++)
-           if (!epf->keep) {
-               char *message;
-
-               message = dupprintf("%s port forwarding from %s%s%d",
-                                   epf->type == 'L' ? "local" :
-                                   epf->type == 'R' ? "remote" : "dynamic",
-                                   epf->saddr ? epf->saddr : "",
-                                   epf->saddr ? ":" : "",
-                                   epf->sport);
-
-               if (epf->type != 'D') {
-                   char *msg2 = dupprintf("%s to %s:%d", message,
-                                          epf->daddr, epf->dport);
-                   sfree(message);
-                   message = msg2;
-               }
-
-               logeventf(ssh, "Cancelling %s", message);
-               sfree(message);
-
-               if (epf->remote) {
-                   struct ssh_rportfwd *rpf = epf->remote;
-                   struct Packet *pktout;
-
-                   /*
-                    * Cancel the port forwarding at the server
-                    * end.
-                    */
-                   if (ssh->version == 1) {
-                       /*
-                        * We cannot cancel listening ports on the
-                        * server side in SSH1! There's no message
-                        * to support it. Instead, we simply remove
-                        * the rportfwd record from the local end
-                        * so that any connections the server tries
-                        * to make on it are rejected.
-                        */
-                   } else {
-                       pktout = ssh2_pkt_init(SSH2_MSG_GLOBAL_REQUEST);
-                       ssh2_pkt_addstring(pktout, "cancel-tcpip-forward");
-                       ssh2_pkt_addbool(pktout, 0);/* _don't_ want reply */
-                       if (epf->saddr) {
-                           ssh2_pkt_addstring(pktout, epf->saddr);
-                       } else if (ssh->cfg.rport_acceptall) {
-                           ssh2_pkt_addstring(pktout, "0.0.0.0");
-                       } else {
-                           ssh2_pkt_addstring(pktout, "127.0.0.1");
-                       }
-                       ssh2_pkt_adduint32(pktout, epf->sport);
-                       ssh2_pkt_send(ssh, pktout);
-                   }
-
-                   del234(ssh->rportfwds, rpf);
-                   free_rportfwd(rpf);
-               } else if (epf->local) {
-                   pfd_terminate(epf->local);
-               }
-
-               delpos234(ssh->portfwds, i);
-               free_portfwd(epf);
-               i--;                   /* so we don't skip one in the list */
-           }
-    }
 }
 
 static void ssh1_smsg_stdout_stderr_data(Ssh ssh, struct Packet *pktin)
@@ -4045,7 +4138,7 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
     /* Remote side is trying to open a channel to talk to a
      * forwarded port. Give them back a local channel number. */
     struct ssh_channel *c;
-    struct ssh_rportfwd pf;
+    struct ssh_rportfwd pf, *pfp;
     int remoteid;
     int hostsize, port;
     char *host, buf[1024];
@@ -4062,8 +4155,9 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
     memcpy(pf.dhost, host, hostsize);
     pf.dhost[hostsize] = '\0';
     pf.dport = port;
+    pfp = find234(ssh->rportfwds, &pf, NULL);
 
-    if (find234(ssh->rportfwds, &pf, NULL) == NULL) {
+    if (pfp == NULL) {
        sprintf(buf, "Rejected remote port open request for %s:%d",
                pf.dhost, port);
        logevent(buf);
@@ -4074,7 +4168,7 @@ static void ssh1_msg_port_open(Ssh ssh, struct Packet *pktin)
                pf.dhost, port);
        logevent(buf);
        e = pfd_newconnect(&c->u.pfd.s, pf.dhost, port,
-                          c, &ssh->cfg);
+                          c, &ssh->cfg, pfp->pfrec->addressfamily);
        if (e != NULL) {
            char buf[256];
            sprintf(buf, "Port open failed: %s", e);
@@ -4204,7 +4298,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
            /* Data for an agent message. Buffer it. */
            while (len > 0) {
                if (c->u.a.lensofar < 4) {
-                   int l = min(4 - c->u.a.lensofar, len);
+                   unsigned int l = min(4 - c->u.a.lensofar, len);
                    memcpy(c->u.a.msglen + c->u.a.lensofar, p,
                           l);
                    p += l;
@@ -4219,7 +4313,7 @@ static void ssh1_msg_channel_data(Ssh ssh, struct Packet *pktin)
                    memcpy(c->u.a.message, c->u.a.msglen, 4);
                }
                if (c->u.a.lensofar >= 4 && len > 0) {
-                   int l =
+                   unsigned int l =
                        min(c->u.a.totallen - c->u.a.lensofar,
                            len);
                    memcpy(c->u.a.message + c->u.a.lensofar, p,
@@ -4265,6 +4359,7 @@ static void ssh1_smsg_exit_status(Ssh ssh, struct Packet *pktin)
      * encrypted packet, we close the session once
      * we've sent EXIT_CONFIRMATION.
      */
+    ssh->close_expected = TRUE;
     ssh_closing((Plug)ssh, NULL, 0, 0);
 }
 
@@ -4504,9 +4599,10 @@ static void ssh1_protocol_setup(Ssh ssh)
     ssh->packet_dispatch[SSH1_MSG_DEBUG] = ssh1_msg_debug;
 }
 
-static void ssh1_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh1_protocol(Ssh ssh, void *vin, int inlen,
                          struct Packet *pktin)
 {
+    unsigned char *in=(unsigned char*)vin;
     if (ssh->state == SSH_STATE_CLOSED)
        return;
 
@@ -4584,9 +4680,10 @@ static void ssh2_mkkey(Ssh ssh, Bignum K, unsigned char *H,
 /*
  * Handle the SSH2 transport layer.
  */
-static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
+static int do_ssh2_transport(Ssh ssh, void *vin, int inlen,
                             struct Packet *pktin)
 {
+    unsigned char *in = (unsigned char *)vin;
     struct do_ssh2_transport_state {
        int nbits, pbits, warn;
        Bignum p, g, e, f, K;
@@ -4608,7 +4705,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
        int n_preferred_ciphers;
        const struct ssh2_ciphers *preferred_ciphers[CIPHER_MAX];
        const struct ssh_compress *preferred_comp;
-       int first_kex;
+       int got_session_id, activated_authconn;
        struct Packet *pktout;
     };
     crState(do_ssh2_transport_state);
@@ -4619,10 +4716,21 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
     s->csmac_tobe = s->scmac_tobe = NULL;
     s->cscomp_tobe = s->sccomp_tobe = NULL;
 
-    s->first_kex = 1;
+    s->got_session_id = s->activated_authconn = FALSE;
 
+    /*
+     * Be prepared to work around the buggy MAC problem.
+     */
+    if (ssh->remote_bugs & BUG_SSH2_HMAC)
+       s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
+    else
+       s->maclist = macs, s->nmacs = lenof(macs);
+
+  begin_key_exchange:
+    ssh->pkt_ctx &= ~SSH2_PKTCTX_KEX_MASK;
     {
-       int i;
+       int i, j, commalist_started;
+
        /*
         * Set up the preferred key exchange. (NULL => warn below here)
         */
@@ -4650,10 +4758,7 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
                break;
            }
        }
-    }
 
-    {
-       int i;
        /*
         * Set up the preferred ciphers. (NULL => warn below here)
         */
@@ -4683,27 +4788,14 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
                break;
            }
        }
-    }
-
-    /*
-     * Set up preferred compression.
-     */
-    if (ssh->cfg.compression)
-       s->preferred_comp = &ssh_zlib;
-    else
-       s->preferred_comp = &ssh_comp_none;
-
-    /*
-     * Be prepared to work around the buggy MAC problem.
-     */
-    if (ssh->remote_bugs & BUG_SSH2_HMAC)
-       s->maclist = buggymacs, s->nmacs = lenof(buggymacs);
-    else
-       s->maclist = macs, s->nmacs = lenof(macs);
 
-  begin_key_exchange:
-    {
-       int i, j, commalist_started;
+       /*
+        * Set up preferred compression.
+        */
+       if (ssh->cfg.compression)
+           s->preferred_comp = &ssh_zlib;
+       else
+           s->preferred_comp = &ssh_comp_none;
 
        /*
         * Enable queueing of outgoing auth- or connection-layer
@@ -4853,9 +4945,12 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
                ssh->kex = k;
            }
            if (ssh->kex) {
-               if (s->warn)
+               if (s->warn) {
+                    sk_set_frozen(ssh->s, 1);
                    askalg(ssh->frontend, "key-exchange algorithm",
                           ssh->kex->name);
+                    sk_set_frozen(ssh->s, 0);
+                }
                break;
            }
        }
@@ -4886,9 +4981,12 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
                }
            }
            if (s->cscipher_tobe) {
-               if (s->warn)
+               if (s->warn) {
+                    sk_set_frozen(ssh->s, 1);
                    askalg(ssh->frontend, "client-to-server cipher",
                           s->cscipher_tobe->name);
+                    sk_set_frozen(ssh->s, 0);
+                }
                break;
            }
        }
@@ -4913,9 +5011,12 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
                }
            }
            if (s->sccipher_tobe) {
-               if (s->warn)
+               if (s->warn) {
+                    sk_set_frozen(ssh->s, 1);
                    askalg(ssh->frontend, "server-to-client cipher",
                           s->sccipher_tobe->name);
+                    sk_set_frozen(ssh->s, 0);
+                }
                break;
            }
        }
@@ -5072,10 +5173,12 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
      */
     s->keystr = ssh->hostkey->fmtkey(s->hkey);
     s->fingerprint = ssh->hostkey->fingerprint(s->hkey);
+    sk_set_frozen(ssh->s, 1);
     verify_ssh_host_key(ssh->frontend,
                        ssh->savedhost, ssh->savedport, ssh->hostkey->keytype,
                        s->keystr, s->fingerprint);
-    if (s->first_kex) {                       /* don't bother logging this in rekeys */
+    sk_set_frozen(ssh->s, 0);
+    if (!s->got_session_id) {     /* don't bother logging this in rekeys */
        logevent("Host key fingerprint is:");
        logevent(s->fingerprint);
     }
@@ -5088,9 +5191,11 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
      * the session id, used in session key construction and
      * authentication.
      */
-    if (s->first_kex)
+    if (!s->got_session_id) {
        memcpy(ssh->v2_session_id, s->exchange_hash,
               sizeof(s->exchange_hash));
+       s->got_session_id = TRUE;
+    }
 
     /*
      * Send SSH2_MSG_NEWKEYS.
@@ -5208,13 +5313,25 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
     }
 
     /*
-     * Key exchange is over. Schedule a timer for our next rekey.
+     * Key exchange is over. Loop straight back round if we have a
+     * deferred rekey reason.
+     */
+    if (ssh->deferred_rekey_reason) {
+       logevent(ssh->deferred_rekey_reason);
+       pktin = NULL;
+       ssh->deferred_rekey_reason = NULL;
+       goto begin_key_exchange;
+    }
+
+    /*
+     * Otherwise, schedule a timer for our next rekey.
      */
     ssh->kex_in_progress = FALSE;
+    ssh->last_rekey = GETTICKCOUNT();
     if (ssh->cfg.ssh_rekey_time != 0)
        ssh->next_rekey = schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
                                         ssh2_timer, ssh);
-    
+
     /*
      * If this is the first key exchange phase, we must pass the
      * SSH2_MSG_NEWKEYS packet to the next layer, not because it
@@ -5223,10 +5340,10 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
      * exchange phases, we don't pass SSH2_MSG_NEWKEYS on, because
      * it would only confuse the layer above.
      */
-    if (!s->first_kex) {
+    if (s->activated_authconn) {
        crReturn(1);
     }
-    s->first_kex = 0;
+    s->activated_authconn = TRUE;
 
     /*
      * Now we're encrypting. Begin returning 1 to the protocol main
@@ -5241,12 +5358,34 @@ static int do_ssh2_transport(Ssh ssh, unsigned char *in, int inlen,
      */
     while (!((pktin && pktin->type == SSH2_MSG_KEXINIT) ||
             (!pktin && inlen == -1))) {
+        wait_for_rekey:
        crReturn(1);
     }
     if (pktin) {
        logevent("Server initiated key re-exchange");
     } else {
-       logevent((char *)in);
+        /*
+         * Special case: if the server bug is set that doesn't
+         * allow rekeying, we give a different log message and
+         * continue waiting. (If such a server _initiates_ a rekey,
+         * we process it anyway!)
+         */
+        if ((ssh->remote_bugs & BUG_SSH2_REKEY)) {
+            logeventf(ssh, "Server bug prevents key re-exchange (%s)",
+                      (char *)in);
+            /* Reset the counters, so that at least this message doesn't
+             * hit the event log _too_ often. */
+            ssh->outgoing_data_size = 0;
+            ssh->incoming_data_size = 0;
+            if (ssh->cfg.ssh_rekey_time != 0) {
+                ssh->next_rekey =
+                    schedule_timer(ssh->cfg.ssh_rekey_time*60*TICKSPERSEC,
+                                   ssh2_timer, ssh);
+            }
+            goto wait_for_rekey;       /* this is utterly horrid */
+        } else {
+            logeventf(ssh, "Initiating key re-exchange (%s)", (char *)in);
+        }
     }
     goto begin_key_exchange;
 
@@ -5311,7 +5450,14 @@ static void ssh2_set_window(struct ssh_channel *c, unsigned newwin)
     if (c->closes != 0)
        return;
 
-    if (newwin > c->v.v2.locwindow) {
+    /*
+     * Only send a WINDOW_ADJUST if there's significantly more window
+     * available than the other end thinks there is.  This saves us
+     * sending a WINDOW_ADJUST for every character in a shell session.
+     *
+     * "Significant" is arbitrarily defined as half the window size.
+     */
+    if (newwin > c->v.v2.locwindow * 2) {
        struct Packet *pktout;
 
        pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_WINDOW_ADJUST);
@@ -5363,7 +5509,7 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
          case CHAN_AGENT:
            while (length > 0) {
                if (c->u.a.lensofar < 4) {
-                   int l = min(4 - c->u.a.lensofar, length);
+                   unsigned int l = min(4 - c->u.a.lensofar, length);
                    memcpy(c->u.a.msglen + c->u.a.lensofar,
                           data, l);
                    data += l;
@@ -5378,7 +5524,7 @@ static void ssh2_msg_channel_data(Ssh ssh, struct Packet *pktin)
                    memcpy(c->u.a.message, c->u.a.msglen, 4);
                }
                if (c->u.a.lensofar >= 4 && length > 0) {
-                   int l =
+                   unsigned int l =
                        min(c->u.a.totallen - c->u.a.lensofar,
                            length);
                    memcpy(c->u.a.message + c->u.a.lensofar,
@@ -5501,6 +5647,7 @@ static void ssh2_msg_channel_close(Ssh ssh, struct Packet *pktin)
        ssh2_pkt_addstring(s->pktout, "en");    /* language tag */
        ssh2_pkt_send_noqueue(ssh, s->pktout);
 #endif
+       ssh->close_expected = TRUE;
        ssh_closing((Plug)ssh, NULL, 0, 0);
     }
 }
@@ -5601,6 +5748,7 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
        ssh2_pkt_addstring(pktout, "en");       /* language tag */
        ssh2_pkt_send_noqueue(ssh, pktout);
        connection_fatal(ssh->frontend, "%s", buf);
+       ssh->close_expected = TRUE;
        ssh_closing((Plug)ssh, NULL, 0, 0);
        return;
     }
@@ -5651,7 +5799,7 @@ static void ssh2_msg_channel_request(Ssh ssh, struct Packet *pktin)
        if (q >= 0 && q+4 <= len) { \
            q = q + 4 + GET_32BIT(p+q); \
            if (q >= 0 && q+4 <= len && \
-                   (q = q + 4 + GET_32BIT(p+q)) && q == len) \
+                   ((q = q + 4 + GET_32BIT(p+q))!= 0) && q == len) \
                result = TRUE; \
        } \
     } while(0)
@@ -5798,7 +5946,8 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
            const char *e = pfd_newconnect(&c->u.pfd.s,
                                           realpf->dhost,
                                           realpf->dport, c,
-                                          &ssh->cfg);
+                                          &ssh->cfg,
+                                          realpf->pfrec->addressfamily);
            logeventf(ssh, "Attempting to forward remote port to "
                      "%s:%d", realpf->dhost, realpf->dport);
            if (e != NULL) {
@@ -5843,7 +5992,7 @@ static void ssh2_msg_channel_open(Ssh ssh, struct Packet *pktin)
        ssh2_pkt_adduint32(pktout, c->remoteid);
        ssh2_pkt_adduint32(pktout, c->localid);
        ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);
-       ssh2_pkt_adduint32(pktout, 0x4000UL);   /* our max pkt size */
+       ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT);      /* our max pkt size */
        ssh2_pkt_send(ssh, pktout);
     }
 }
@@ -5870,8 +6019,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET
        } type;
        int gotit, need_pw, can_pubkey, can_passwd, can_keyb_inter;
-       int tried_pubkey_config, tried_agent, tried_keyb_inter;
-       int kbd_inter_running;
+       int tried_pubkey_config, tried_agent;
+       int kbd_inter_running, kbd_inter_refused;
        int we_are_in;
        int num_prompts, curr_prompt, echo;
        char username[100];
@@ -5953,6 +6102,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                     * Terminate.
                     */
                    logevent("No username provided. Abandoning session.");
+                   ssh->close_expected = TRUE;
                     ssh_closing((Plug)ssh, NULL, 0, 0);
                    crStopV;
                }
@@ -6000,8 +6150,8 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
 
        s->tried_pubkey_config = FALSE;
        s->tried_agent = FALSE;
-       s->tried_keyb_inter = FALSE;
        s->kbd_inter_running = FALSE;
+       s->kbd_inter_refused = FALSE;
        /* Load the pub half of ssh->cfg.keyfile so we notice if it's in Pageant */
        if (!filename_is_null(ssh->cfg.keyfile)) {
            int keytype;
@@ -6068,6 +6218,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                 */
                if (!s->gotit)
                    s->curr_prompt = 0;
+           } else if (pktin->type == SSH2_MSG_USERAUTH_PASSWD_CHANGEREQ) {
+               /* FIXME: perhaps we should support this? */
+               bombout(("PASSWD_CHANGEREQ not yet supported"));
+               crStopV;
            } else if (pktin->type != SSH2_MSG_USERAUTH_FAILURE) {
                bombout(("Strange packet received during authentication: type %d",
                         pktin->type));
@@ -6392,10 +6546,10 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                }
            }
 
-           if (!s->method && s->can_keyb_inter && !s->tried_keyb_inter) {
+           if (!s->method && s->can_keyb_inter && !s->kbd_inter_refused &&
+               !s->kbd_inter_running) {
                s->method = AUTH_KEYBOARD_INTERACTIVE;
                s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
-               s->tried_keyb_inter = TRUE;
 
                ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
                ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
@@ -6414,6 +6568,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                        s->gotit = TRUE;
                    logevent("Keyboard-interactive authentication refused");
                    s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE_QUIET;
+                   s->kbd_inter_refused = TRUE; /* don't try it again */
                    continue;
                }
 
@@ -6424,7 +6579,6 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
            if (s->kbd_inter_running) {
                s->method = AUTH_KEYBOARD_INTERACTIVE;
                s->type = AUTH_TYPE_KEYBOARD_INTERACTIVE;
-               s->tried_keyb_inter = TRUE;
 
                ssh->pkt_ctx &= ~SSH2_PKTCTX_AUTH_MASK;
                ssh->pkt_ctx |= SSH2_PKTCTX_KBDINTER;
@@ -6510,6 +6664,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                        logevent("Unable to authenticate");
                        connection_fatal(ssh->frontend,
                                         "Unable to authenticate");
+                       ssh->close_expected = TRUE;
                         ssh_closing((Plug)ssh, NULL, 0, 0);
                        crStopV;
                    }
@@ -6612,20 +6767,16 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                }
            } else if (s->method == AUTH_PASSWORD) {
                /*
-                * We send the password packet lumped tightly together with
-                * an SSH_MSG_IGNORE packet. The IGNORE packet contains a
-                * string long enough to make the total length of the two
-                * packets constant. This should ensure that a passive
-                * listener doing traffic analyis can't work out the length
-                * of the password.
+                * We pad out the password packet to 256 bytes to make
+                * it harder for an attacker to find the length of the
+                * user's password.
                 *
-                * For this to work, we need an assumption about the
-                * maximum length of the password packet. I think 256 is
-                * pretty conservative. Anyone using a password longer than
-                * that probably doesn't have much to worry about from
+                * Anyone using a password longer than 256 bytes
+                * probably doesn't have much to worry about from
                 * people who find out how long their password is!
                 */
                s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_REQUEST);
+               s->pktout->forcepad = 256;
                ssh2_pkt_addstring(s->pktout, s->username);
                ssh2_pkt_addstring(s->pktout, "ssh-connection");        /* service requested */
                ssh2_pkt_addstring(s->pktout, "password");
@@ -6634,46 +6785,13 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                ssh2_pkt_addstring(s->pktout, s->password);
                memset(s->password, 0, sizeof(s->password));
                end_log_omission(ssh, s->pktout);
-               ssh2_pkt_defer(ssh, s->pktout);
-               /*
-                * We'll include a string that's an exact multiple of the
-                * cipher block size. If the cipher is NULL for some
-                * reason, we don't do this trick at all because we gain
-                * nothing by it.
-                */
-               if (ssh->cscipher) {
-                   int stringlen, i;
-
-                   stringlen = (256 - ssh->deferred_len);
-                   stringlen += ssh->cscipher->blksize - 1;
-                   stringlen -= (stringlen % ssh->cscipher->blksize);
-                   if (ssh->cscomp) {
-                       /*
-                        * Temporarily disable actual compression,
-                        * so we can guarantee to get this string
-                        * exactly the length we want it. The
-                        * compression-disabling routine should
-                        * return an integer indicating how many
-                        * bytes we should adjust our string length
-                        * by.
-                        */
-                       stringlen -= 
-                           ssh->cscomp->disable_compression(ssh->cs_comp_ctx);
-                   }
-                   s->pktout = ssh2_pkt_init(SSH2_MSG_IGNORE);
-                   ssh2_pkt_addstring_start(s->pktout);
-                   for (i = 0; i < stringlen; i++) {
-                       char c = (char) random_byte();
-                       ssh2_pkt_addstring_data(s->pktout, &c, 1);
-                   }
-                   ssh2_pkt_defer(ssh, s->pktout);
-               }
-               ssh_pkt_defersend(ssh);
+               ssh2_pkt_send(ssh, s->pktout);
                logevent("Sent password");
                s->type = AUTH_TYPE_PASSWORD;
            } else if (s->method == AUTH_KEYBOARD_INTERACTIVE) {
                if (s->curr_prompt == 0) {
                    s->pktout = ssh2_pkt_init(SSH2_MSG_USERAUTH_INFO_RESPONSE);
+                   s->pktout->forcepad = 256;
                    ssh2_pkt_adduint32(s->pktout, s->num_prompts);
                }
                if (s->need_pw) {      /* only add pw if we just got one! */
@@ -6708,6 +6826,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
                                   " methods available");
                ssh2_pkt_addstring(s->pktout, "en");    /* language tag */
                ssh2_pkt_send_noqueue(ssh, s->pktout);
+               ssh->close_expected = TRUE;
                 ssh_closing((Plug)ssh, NULL, 0, 0);
                crStopV;
            }
@@ -6743,7 +6862,7 @@ static void do_ssh2_authconn(Ssh ssh, unsigned char *in, int inlen,
        ssh2_pkt_adduint32(s->pktout, ssh->mainchan->localid);
        ssh->mainchan->v.v2.locwindow = OUR_V2_WINSIZE;
        ssh2_pkt_adduint32(s->pktout, ssh->mainchan->v.v2.locwindow);/* our window size */
-       ssh2_pkt_adduint32(s->pktout, 0x4000UL);      /* our max pkt size */
+       ssh2_pkt_adduint32(s->pktout, OUR_V2_MAXPKT);    /* our max pkt size */
        ssh2_pkt_send(ssh, s->pktout);
        crWaitUntilV(pktin);
        if (pktin->type != SSH2_MSG_CHANNEL_OPEN_CONFIRMATION) {
@@ -7213,16 +7332,16 @@ static void ssh2_timer(void *ctx, long now)
 {
     Ssh ssh = (Ssh)ctx;
 
-    if (!ssh->kex_in_progress &&
+    if (!ssh->kex_in_progress && ssh->cfg.ssh_rekey_time != 0 &&
        now - ssh->next_rekey >= 0) {
-       do_ssh2_transport(ssh, "Initiating key re-exchange (timeout)",
-                         -1, NULL);
+       do_ssh2_transport(ssh, "timeout", -1, NULL);
     }
 }
 
-static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
+static void ssh2_protocol(Ssh ssh, void *vin, int inlen,
                          struct Packet *pktin)
 {
+    unsigned char *in = (unsigned char *)vin;
     if (ssh->state == SSH_STATE_CLOSED)
        return;
 
@@ -7231,8 +7350,7 @@ static void ssh2_protocol(Ssh ssh, unsigned char *in, int inlen,
        if (!ssh->kex_in_progress &&
            ssh->max_data_size != 0 &&
            ssh->incoming_data_size > ssh->max_data_size)
-           do_ssh2_transport(ssh, "Initiating key re-exchange "
-                             "(too much data received)", -1, NULL);
+           do_ssh2_transport(ssh, "too much data received", -1, NULL);
     }
 
     if (pktin && ssh->packet_dispatch[pktin->type]) {
@@ -7291,6 +7409,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->kex_ctx = NULL;
     ssh->hostkey = NULL;
     ssh->exitcode = -1;
+    ssh->close_expected = FALSE;
     ssh->state = SSH_STATE_PREPACKET;
     ssh->size_needed = FALSE;
     ssh->eof_needed = FALSE;
@@ -7323,6 +7442,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle,
     ssh->queuelen = ssh->queuesize = 0;
     ssh->queueing = FALSE;
     ssh->qhead = ssh->qtail = NULL;
+    ssh->deferred_rekey_reason = NULL;
 
     *backend_handle = ssh;
 
@@ -7337,6 +7457,7 @@ static const char *ssh_init(void *frontend_handle, void **backend_handle,
 
     ssh->channels = NULL;
     ssh->rportfwds = NULL;
+    ssh->portfwds = NULL;
 
     ssh->send_ok = 0;
     ssh->editing = 0;
@@ -7444,7 +7565,7 @@ static void ssh_free(void *handle)
        ssh->crcda_ctx = NULL;
     }
     if (ssh->s)
-       ssh_do_close(ssh);
+       ssh_do_close(ssh, TRUE);
     expire_timer_context(ssh);
     if (ssh->pinger)
        pinger_free(ssh->pinger);
@@ -7459,9 +7580,54 @@ static void ssh_free(void *handle)
 static void ssh_reconfig(void *handle, Config *cfg)
 {
     Ssh ssh = (Ssh) handle;
+    char *rekeying = NULL, rekey_mandatory = FALSE;
+    unsigned long old_max_data_size;
+
     pinger_reconfig(ssh->pinger, &ssh->cfg, cfg);
     ssh_setup_portfwd(ssh, cfg);
+
+    if (ssh->cfg.ssh_rekey_time != cfg->ssh_rekey_time &&
+       cfg->ssh_rekey_time != 0) {
+       long new_next = ssh->last_rekey + cfg->ssh_rekey_time*60*TICKSPERSEC;
+       long now = GETTICKCOUNT();
+
+       if (new_next - now < 0) {
+           rekeying = "timeout shortened";
+       } else {
+           ssh->next_rekey = schedule_timer(new_next - now, ssh2_timer, ssh);
+       }
+    }
+
+    old_max_data_size = ssh->max_data_size;
+    ssh->max_data_size = parse_blocksize(cfg->ssh_rekey_data);
+    if (old_max_data_size != ssh->max_data_size &&
+       ssh->max_data_size != 0) {
+       if (ssh->outgoing_data_size > ssh->max_data_size ||
+           ssh->incoming_data_size > ssh->max_data_size)
+           rekeying = "data limit lowered";
+    }
+
+    if (ssh->cfg.compression != cfg->compression) {
+       rekeying = "compression setting changed";
+       rekey_mandatory = TRUE;
+    }
+
+    if (ssh->cfg.ssh2_des_cbc != cfg->ssh2_des_cbc ||
+       memcmp(ssh->cfg.ssh_cipherlist, cfg->ssh_cipherlist,
+              sizeof(ssh->cfg.ssh_cipherlist))) {
+       rekeying = "cipher settings changed";
+       rekey_mandatory = TRUE;
+    }
+
     ssh->cfg = *cfg;                  /* STRUCTURE COPY */
+
+    if (rekeying) {
+       if (!ssh->kex_in_progress) {
+           do_ssh2_transport(ssh, rekeying, -1, NULL);
+       } else if (rekey_mandatory) {
+           ssh->deferred_rekey_reason = rekeying;
+       }
+    }
 }
 
 /*
@@ -7662,8 +7828,7 @@ static void ssh_special(void *handle, Telnet_Special code)
        }
     } else if (code == TS_REKEY) {
        if (!ssh->kex_in_progress && ssh->version == 2) {
-           do_ssh2_transport(ssh, "Initiating key re-exchange at"
-                             " user request", -1, NULL);
+           do_ssh2_transport(ssh, "at user request", -1, NULL);
        }
     } else if (code == TS_BRK) {
        if (ssh->state == SSH_STATE_CLOSED
@@ -7763,7 +7928,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
                    PKT_INT, c->localid,
                    PKT_STR, hostname,
                    PKT_INT, port,
-                   //PKT_STR, <org:orgport>,
+                   /* PKT_STR, <org:orgport>, */
                    PKT_END);
     } else {
        pktout = ssh2_pkt_init(SSH2_MSG_CHANNEL_OPEN);
@@ -7771,7 +7936,7 @@ void ssh_send_port_open(void *channel, char *hostname, int port, char *org)
        ssh2_pkt_adduint32(pktout, c->localid);
        c->v.v2.locwindow = OUR_V2_WINSIZE;
        ssh2_pkt_adduint32(pktout, c->v.v2.locwindow);/* our window size */
-       ssh2_pkt_adduint32(pktout, 0x4000UL);      /* our max pkt size */
+       ssh2_pkt_adduint32(pktout, OUR_V2_MAXPKT);      /* our max pkt size */
        ssh2_pkt_addstring(pktout, hostname);
        ssh2_pkt_adduint32(pktout, port);
        /*
@@ -7830,6 +7995,16 @@ static int ssh_return_exitcode(void *handle)
 }
 
 /*
+ * cfg_info for SSH is the currently running version of the
+ * protocol. (1 for 1; 2 for 2; 0 for not-decided-yet.)
+ */
+static int ssh_cfg_info(void *handle)
+{
+    Ssh ssh = (Ssh) handle;
+    return ssh->version;
+}
+
+/*
  * Gross hack: pscp will try to start SFTP but fall back to scp1 if
  * that fails. This variable is the means by which scp.c can reach
  * into the SSH code and find out which one it got.
@@ -7856,5 +8031,6 @@ Backend ssh_backend = {
     ssh_provide_ldisc,
     ssh_provide_logctx,
     ssh_unthrottle,
+    ssh_cfg_info,
     22
 };