1 files changed, 222 insertions, 161 deletions

diff --git a/serverloop.c b/serverloop.c
index 7be83e2d3..d7b04b37c 100644
--- a/serverloop.c
+++ b/serverloop.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: serverloop.c,v 1.209 2018/07/27 05:13:02 dtucker Exp $ */
+/* $OpenBSD: serverloop.c,v 1.215 2019/03/27 09:29:14 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -49,6 +49,7 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <pwd.h>
+#include <limits.h>
 #include <signal.h>
 #include <string.h>
 #include <termios.h>
@@ -98,7 +99,7 @@ static volatile sig_atomic_t child_terminated = 0;	/* The child has terminated.
 static volatile sig_atomic_t received_sigterm = 0;
 
 /* prototypes */
-static void server_init_dispatch(void);
+static void server_init_dispatch(struct ssh *);
 
 /* requested tunnel forwarding interface(s), shared with session.c */
 char *tun_fwd_ifnames = NULL;
@@ -179,11 +180,12 @@ sigterm_handler(int sig)
 static void
 client_alive_check(struct ssh *ssh)
 {
-        int channel_id;
         char remote_id[512];
+        int r, channel_id;
 
         /* timeout, check to see how many we have had */
-        if (packet_inc_alive_timeouts() > options.client_alive_count_max) {
+        if (ssh_packet_inc_alive_timeouts(ssh) >
+            options.client_alive_count_max) {
                 sshpkt_fmt_connection_id(ssh, remote_id, sizeof(remote_id));
                 logit("Timeout, client not responding from %s", remote_id);
                 cleanup_exit(255);
@@ -194,14 +196,17 @@ client_alive_check(struct ssh *ssh)
          * we should get back a failure
          */
         if ((channel_id = channel_find_open(ssh)) == -1) {
-                packet_start(SSH2_MSG_GLOBAL_REQUEST);
-                packet_put_cstring("keepalive@openssh.com");
-                packet_put_char(1);     /* boolean: want reply */
+                if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
+                    (r = sshpkt_put_cstring(ssh, "keepalive@openssh.com"))
+                    != 0 ||
+                    (r = sshpkt_put_u8(ssh, 1)) != 0) /* boolean: want reply */
+                        fatal("%s: %s", __func__, ssh_err(r));
         } else {
                 channel_request_start(ssh, channel_id,
                     "keepalive@openssh.com", 1);
         }
-        packet_send();
+        if ((r = sshpkt_send(ssh)) != 0)
+                fatal("%s: %s", __func__, ssh_err(r));
 }
 
 /*
@@ -220,6 +225,7 @@ wait_until_can_do_something(struct ssh *ssh,
         int ret;
         time_t minwait_secs = 0;
         int client_alive_scheduled = 0;
+        /* time we last heard from the client OR sent a keepalive */
         static time_t last_client_time;
 
         /* Allocate and update select() masks for channel descriptors. */
@@ -242,9 +248,10 @@ wait_until_can_do_something(struct ssh *ssh,
                 uint64_t keepalive_ms =
                     (uint64_t)options.client_alive_interval * 1000;
 
-                client_alive_scheduled = 1;
-                if (max_time_ms == 0 || max_time_ms > keepalive_ms)
+                if (max_time_ms == 0 || max_time_ms > keepalive_ms) {
                         max_time_ms = keepalive_ms;
+                        client_alive_scheduled = 1;
+                }
         }
 
 #if 0
@@ -258,14 +265,14 @@ wait_until_can_do_something(struct ssh *ssh,
          * If we have buffered packet data going to the client, mark that
          * descriptor.
          */
-        if (packet_have_data_to_write())
+        if (ssh_packet_have_data_to_write(ssh))
                 FD_SET(connection_out, *writesetp);
 
         /*
          * If child has terminated and there is enough buffer space to read
          * from it, then read as much as is available and exit.
          */
-        if (child_terminated && packet_not_very_much_data_to_write())
+        if (child_terminated && ssh_packet_not_very_much_data_to_write(ssh))
                 if (max_time_ms == 0 || client_alive_scheduled)
                         max_time_ms = 100;
 
@@ -288,13 +295,15 @@ wait_until_can_do_something(struct ssh *ssh,
         } else if (client_alive_scheduled) {
                 time_t now = monotime();
 
-                if (ret == 0) { /* timeout */
+                /*
+                 * If the select timed out, or returned for some other reason
+                 * but we haven't heard from the client in time, send keepalive.
+                 */
+                if (ret == 0 || (last_client_time != 0 && last_client_time +
+                    options.client_alive_interval <= now)) {
                         client_alive_check(ssh);
-                } else if (FD_ISSET(connection_in, *readsetp)) {
                         last_client_time = now;
-                } else if (last_client_time != 0 && last_client_time +
-                    options.client_alive_interval <= now) {
-                        client_alive_check(ssh);
+                } else if (FD_ISSET(connection_in, *readsetp)) {
                         last_client_time = now;
                 }
         }
@@ -309,7 +318,7 @@ wait_until_can_do_something(struct ssh *ssh,
 static int
 process_input(struct ssh *ssh, fd_set *readset, int connection_in)
 {
-        int len;
+        int r, len;
         char buf[16384];
 
         /* Read and buffer any input data from the client. */
@@ -330,7 +339,10 @@ process_input(struct ssh *ssh, fd_set *readset, int connection_in)
                         }
                 } else {
                         /* Buffer any received data. */
-                        packet_process_incoming(buf, len);
+                        if ((r = ssh_packet_process_incoming(ssh, buf, len))
+                            != 0)
+                                fatal("%s: ssh_packet_process_incoming: %s",
+                                    __func__, ssh_err(r));
                 }
         }
         return 0;
@@ -340,11 +352,16 @@ process_input(struct ssh *ssh, fd_set *readset, int connection_in)
  * Sends data from internal buffers to client program stdin.
  */
 static void
-process_output(fd_set *writeset, int connection_out)
+process_output(struct ssh *ssh, fd_set *writeset, int connection_out)
 {
+        int r;
+
         /* Send any buffered packet data to the client. */
-        if (FD_ISSET(connection_out, writeset))
-                packet_write_poll();
+        if (FD_ISSET(connection_out, writeset)) {
+                if ((r = ssh_packet_write_poll(ssh)) != 0)
+                        fatal("%s: ssh_packet_write_poll: %s",
+                            __func__, ssh_err(r));
+        }
 }
 
 static void
@@ -387,8 +404,8 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
 
         signal(SIGCHLD, sigchld_handler);
         child_terminated = 0;
-        connection_in = packet_get_connection_in();
-        connection_out = packet_get_connection_out();
+        connection_in = ssh_packet_get_connection_in(ssh);
+        connection_out = ssh_packet_get_connection_out(ssh);
 
         if (!use_privsep) {
                 signal(SIGTERM, sigterm_handler);
@@ -401,18 +418,21 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
         max_fd = MAXIMUM(connection_in, connection_out);
         max_fd = MAXIMUM(max_fd, notify_pipe[0]);
 
-        server_init_dispatch();
+        server_init_dispatch(ssh);
 
         for (;;) {
                 process_buffered_input_packets(ssh);
 
                 if (!ssh_packet_is_rekeying(ssh) &&
-                    packet_not_very_much_data_to_write())
+                    ssh_packet_not_very_much_data_to_write(ssh))
                         channel_output_poll(ssh);
-                if (options.rekey_interval > 0 && !ssh_packet_is_rekeying(ssh))
-                        rekey_timeout_ms = packet_get_rekey_timeout() * 1000;
-                else
+                if (options.rekey_interval > 0 &&
+                    !ssh_packet_is_rekeying(ssh)) {
+                        rekey_timeout_ms = ssh_packet_get_rekey_timeout(ssh) *
+                            1000;
+                } else {
                         rekey_timeout_ms = 0;
+                }
 
                 wait_until_can_do_something(ssh, connection_in, connection_out,
                     &readset, &writeset, &max_fd, &nalloc, rekey_timeout_ms);
@@ -428,7 +448,7 @@ server_loop2(struct ssh *ssh, Authctxt *authctxt)
                         channel_after_select(ssh, readset, writeset);
                 if (process_input(ssh, readset, connection_in) < 0)
                         break;
-                process_output(writeset, connection_out);
+                process_output(ssh, writeset, connection_out);
         }
         collect_children(ssh);
 
@@ -451,7 +471,7 @@ server_input_keep_alive(int type, u_int32_t seq, struct ssh *ssh)
          * even if this was generated by something other than
          * the bogus CHANNEL_REQUEST we send for keepalives.
          */
-        packet_set_alive_timeouts(0);
+        ssh_packet_set_alive_timeouts(ssh, 0);
         return 0;
 }
 
@@ -459,16 +479,28 @@ static Channel *
 server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
 {
         Channel *c = NULL;
-        char *target, *originator;
-        u_short target_port, originator_port;
-
-        target = packet_get_string(NULL);
-        target_port = packet_get_int();
-        originator = packet_get_string(NULL);
-        originator_port = packet_get_int();
-        packet_check_eom();
+        char *target = NULL, *originator = NULL;
+        u_int target_port = 0, originator_port = 0;
+        int r;
+
+        if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &target_port)) != 0 ||
+            (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
+            (r = sshpkt_get_end(ssh)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+        if (target_port > 0xFFFF) {
+                error("%s: invalid target port", __func__);
+                *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
+                goto out;
+        }
+        if (originator_port > 0xFFFF) {
+                error("%s: invalid originator port", __func__);
+                *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
+                goto out;
+        }
 
-        debug("%s: originator %s port %d, target %s port %d", __func__,
+        debug("%s: originator %s port %u, target %s port %u", __func__,
             originator, originator_port, target, target_port);
 
         /* XXX fine grained permissions */
@@ -485,9 +517,9 @@ server_request_direct_tcpip(struct ssh *ssh, int *reason, const char **errmsg)
                         *reason = SSH2_OPEN_ADMINISTRATIVELY_PROHIBITED;
         }
 
+ out:
         free(originator);
         free(target);
-
         return c;
 }
 
@@ -495,17 +527,23 @@ static Channel *
 server_request_direct_streamlocal(struct ssh *ssh)
 {
         Channel *c = NULL;
-        char *target, *originator;
-        u_short originator_port;
+        char *target = NULL, *originator = NULL;
+        u_int originator_port = 0;
         struct passwd *pw = the_authctxt->pw;
+        int r;
 
         if (pw == NULL || !the_authctxt->valid)
                 fatal("%s: no/invalid user", __func__);
 
-        target = packet_get_string(NULL);
-        originator = packet_get_string(NULL);
-        originator_port = packet_get_int();
-        packet_check_eom();
+        if ((r = sshpkt_get_cstring(ssh, &target, NULL)) != 0 ||
+            (r = sshpkt_get_cstring(ssh, &originator, NULL)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &originator_port)) != 0 ||
+            (r = sshpkt_get_end(ssh)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+        if (originator_port > 0xFFFF) {
+                error("%s: invalid originator port", __func__);
+                goto out;
+        }
 
         debug("%s: originator %s port %d, target %s", __func__,
             originator, originator_port, target);
@@ -522,9 +560,9 @@ server_request_direct_streamlocal(struct ssh *ssh)
                     originator, originator_port, target);
         }
 
+out:
         free(originator);
         free(target);
-
         return c;
 }
 
@@ -532,27 +570,35 @@ static Channel *
 server_request_tun(struct ssh *ssh)
 {
         Channel *c = NULL;
-        int mode, tun, sock;
+        u_int mode, tun;
+        int r, sock;
         char *tmp, *ifname = NULL;
 
-        mode = packet_get_int();
+        if ((r = sshpkt_get_u32(ssh, &mode)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse mode", __func__);
         switch (mode) {
         case SSH_TUNMODE_POINTOPOINT:
         case SSH_TUNMODE_ETHERNET:
                 break;
         default:
-                packet_send_debug("Unsupported tunnel device mode.");
+                ssh_packet_send_debug(ssh, "Unsupported tunnel device mode.");
                 return NULL;
         }
         if ((options.permit_tun & mode) == 0) {
-                packet_send_debug("Server has rejected tunnel device "
+                ssh_packet_send_debug(ssh, "Server has rejected tunnel device "
                     "forwarding");
                 return NULL;
         }
 
-        tun = packet_get_int();
+        if ((r = sshpkt_get_u32(ssh, &tun)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse device", __func__);
+        if (tun > INT_MAX) {
+                debug("%s: invalid tun", __func__);
+                goto done;
+        }
         if (auth_opts->force_tun_device != -1) {
-                if (tun != SSH_TUNID_ANY && auth_opts->force_tun_device != tun)
+                if (tun != SSH_TUNID_ANY &&
+                    auth_opts->force_tun_device != (int)tun)
                         goto done;
                 tun = auth_opts->force_tun_device;
         }
@@ -585,7 +631,7 @@ server_request_tun(struct ssh *ssh)
 
  done:
         if (c == NULL)
-                packet_send_debug("Failed to open the tunnel device.");
+                ssh_packet_send_debug(ssh, "Failed to open the tunnel device.");
         return c;
 }
 
@@ -593,13 +639,15 @@ static Channel *
 server_request_session(struct ssh *ssh)
 {
         Channel *c;
+        int r;
 
         debug("input_session_request");
-        packet_check_eom();
+        if ((r = sshpkt_get_end(ssh)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
 
         if (no_more_sessions) {
-                packet_disconnect("Possible attack: attempt to open a session "
-                    "after additional sessions disabled");
+                ssh_packet_disconnect(ssh, "Possible attack: attempt to open a "
+                    "session after additional sessions disabled");
         }
 
         /*
@@ -624,20 +672,22 @@ static int
 server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
 {
         Channel *c = NULL;
-        char *ctype;
+        char *ctype = NULL;
         const char *errmsg = NULL;
-        int rchan, reason = SSH2_OPEN_CONNECT_FAILED;
-        u_int rmaxpack, rwindow, len;
-
-        ctype = packet_get_string(&len);
-        rchan = packet_get_int();
-        rwindow = packet_get_int();
-        rmaxpack = packet_get_int();
-
-        debug("%s: ctype %s rchan %d win %d max %d", __func__,
+        int r, reason = SSH2_OPEN_CONNECT_FAILED;
+        u_int rchan = 0, rmaxpack = 0, rwindow = 0;
+
+        if ((r = sshpkt_get_cstring(ssh, &ctype, NULL)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &rchan)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &rwindow)) != 0 ||
+            (r = sshpkt_get_u32(ssh, &rmaxpack)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+        debug("%s: ctype %s rchan %u win %u max %u", __func__,
             ctype, rchan, rwindow, rmaxpack);
 
-        if (strcmp(ctype, "session") == 0) {
+        if (rchan > INT_MAX) {
+                error("%s: invalid remote channel ID", __func__);
+        } else if (strcmp(ctype, "session") == 0) {
                 c = server_request_session(ssh);
         } else if (strcmp(ctype, "direct-tcpip") == 0) {
                 c = server_request_direct_tcpip(ssh, &reason, &errmsg);
@@ -648,26 +698,32 @@ server_input_channel_open(int type, u_int32_t seq, struct ssh *ssh)
         }
         if (c != NULL) {
                 debug("%s: confirm %s", __func__, ctype);
-                c->remote_id = rchan;
+                c->remote_id = (int)rchan;
                 c->have_remote_id = 1;
                 c->remote_window = rwindow;
                 c->remote_maxpacket = rmaxpack;
                 if (c->type != SSH_CHANNEL_CONNECTING) {
-                        packet_start(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION);
-                        packet_put_int(c->remote_id);
-                        packet_put_int(c->self);
-                        packet_put_int(c->local_window);
-                        packet_put_int(c->local_maxpacket);
-                        packet_send();
+                        if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION)) != 0 ||
+                            (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
+                            (r = sshpkt_put_u32(ssh, c->self)) != 0 ||
+                            (r = sshpkt_put_u32(ssh, c->local_window)) != 0 ||
+                            (r = sshpkt_put_u32(ssh, c->local_maxpacket)) != 0 ||
+                            (r = sshpkt_send(ssh)) != 0) {
+                                sshpkt_fatal(ssh, r,
+                                    "%s: send open confirm", __func__);
+                        }
                 }
         } else {
                 debug("%s: failure %s", __func__, ctype);
-                packet_start(SSH2_MSG_CHANNEL_OPEN_FAILURE);
-                packet_put_int(rchan);
-                packet_put_int(reason);
-                packet_put_cstring(errmsg ? errmsg : "open failed");
-                packet_put_cstring("");
-                packet_send();
+                if ((r = sshpkt_start(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE)) != 0 ||
+                    (r = sshpkt_put_u32(ssh, rchan)) != 0 ||
+                    (r = sshpkt_put_u32(ssh, reason)) != 0 ||
+                    (r = sshpkt_put_cstring(ssh, errmsg ? errmsg : "open failed")) != 0 ||
+                    (r = sshpkt_put_cstring(ssh, "")) != 0 ||
+                    (r = sshpkt_send(ssh)) != 0) {
+                        sshpkt_fatal(ssh, r,
+                            "%s: send open failure", __func__);
+                }
         }
         free(ctype);
         return 0;
@@ -730,9 +786,9 @@ server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
                     (r = sshbuf_put_string(sigbuf,
                     ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||
                     (r = sshkey_puts(key, sigbuf)) != 0 ||
-                    (r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,
+                    (r = ssh->kex->sign(ssh, key_prv, key_pub, &sig, &slen,
                     sshbuf_ptr(sigbuf), sshbuf_len(sigbuf),
-                    use_kexsigtype ? ssh->kex->hostkey_alg : NULL, 0)) != 0 ||
+                    use_kexsigtype ? ssh->kex->hostkey_alg : NULL)) != 0 ||
                     (r = sshbuf_put_string(resp, sig, slen)) != 0) {
                         error("%s: couldn't prepare signature: %s",
                             __func__, ssh_err(r));
@@ -754,65 +810,66 @@ server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
 static int
 server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
 {
-        char *rtype;
-        int want_reply;
+        char *rtype = NULL;
+        u_char want_reply = 0;
         int r, success = 0, allocated_listen_port = 0;
+        u_int port = 0;
         struct sshbuf *resp = NULL;
         struct passwd *pw = the_authctxt->pw;
+        struct Forward fwd;
 
+        memset(&fwd, 0, sizeof(fwd));
         if (pw == NULL || !the_authctxt->valid)
                 fatal("%s: no/invalid user", __func__);
 
-        rtype = packet_get_string(NULL);
-        want_reply = packet_get_char();
+        if ((r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
+            (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
         debug("%s: rtype %s want_reply %d", __func__, rtype, want_reply);
 
         /* -R style forwarding */
         if (strcmp(rtype, "tcpip-forward") == 0) {
-                struct Forward fwd;
-
-                memset(&fwd, 0, sizeof(fwd));
-                fwd.listen_host = packet_get_string(NULL);
-                fwd.listen_port = (u_short)packet_get_int();
-                debug("%s: tcpip-forward listen %s port %d", __func__,
-                    fwd.listen_host, fwd.listen_port);
-
+                if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
+                    (r = sshpkt_get_u32(ssh, &port)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: parse tcpip-forward", __func__);
+                debug("%s: tcpip-forward listen %s port %u", __func__,
+                    fwd.listen_host, port);
+                if (port <= INT_MAX)
+                        fwd.listen_port = (int)port;
                 /* check permissions */
-                if ((options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
+                if (port > INT_MAX ||
+                    (options.allow_tcp_forwarding & FORWARD_REMOTE) == 0 ||
                     !auth_opts->permit_port_forwarding_flag ||
                     options.disable_forwarding ||
                     (!want_reply && fwd.listen_port == 0) ||
                     (fwd.listen_port != 0 &&
                      !bind_permitted(fwd.listen_port, pw->pw_uid))) {
                         success = 0;
-                        packet_send_debug("Server has disabled port forwarding.");
+                        ssh_packet_send_debug(ssh, "Server has disabled port forwarding.");
                 } else {
                         /* Start listening on the port */
                         success = channel_setup_remote_fwd_listener(ssh, &fwd,
                             &allocated_listen_port, &options.fwd_opts);
                 }
-                free(fwd.listen_host);
                 if ((resp = sshbuf_new()) == NULL)
                         fatal("%s: sshbuf_new", __func__);
                 if (allocated_listen_port != 0 &&
                     (r = sshbuf_put_u32(resp, allocated_listen_port)) != 0)
                         fatal("%s: sshbuf_put_u32: %s", __func__, ssh_err(r));
         } else if (strcmp(rtype, "cancel-tcpip-forward") == 0) {
-                struct Forward fwd;
+                if ((r = sshpkt_get_cstring(ssh, &fwd.listen_host, NULL)) != 0 ||
+                    (r = sshpkt_get_u32(ssh, &port)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: parse cancel-tcpip-forward", __func__);
 
-                memset(&fwd, 0, sizeof(fwd));
-                fwd.listen_host = packet_get_string(NULL);
-                fwd.listen_port = (u_short)packet_get_int();
                 debug("%s: cancel-tcpip-forward addr %s port %d", __func__,
-                    fwd.listen_host, fwd.listen_port);
-
-                success = channel_cancel_rport_listener(ssh, &fwd);
-                free(fwd.listen_host);
+                    fwd.listen_host, port);
+                if (port <= INT_MAX) {
+                        fwd.listen_port = (int)port;
+                        success = channel_cancel_rport_listener(ssh, &fwd);
+                }
         } else if (strcmp(rtype, "streamlocal-forward@openssh.com") == 0) {
-                struct Forward fwd;
-
-                memset(&fwd, 0, sizeof(fwd));
-                fwd.listen_path = packet_get_string(NULL);
+                if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: parse streamlocal-forward@openssh.com", __func__);
                 debug("%s: streamlocal-forward listen path %s", __func__,
                     fwd.listen_path);
 
@@ -822,39 +879,37 @@ server_input_global_request(int type, u_int32_t seq, struct ssh *ssh)
                     options.disable_forwarding ||
                     (pw->pw_uid != 0 && !use_privsep)) {
                         success = 0;
-                        packet_send_debug("Server has disabled "
+                        ssh_packet_send_debug(ssh, "Server has disabled "
                             "streamlocal forwarding.");
                 } else {
                         /* Start listening on the socket */
                         success = channel_setup_remote_fwd_listener(ssh,
                             &fwd, NULL, &options.fwd_opts);
                 }
-                free(fwd.listen_path);
         } else if (strcmp(rtype, "cancel-streamlocal-forward@openssh.com") == 0) {
-                struct Forward fwd;
-
-                memset(&fwd, 0, sizeof(fwd));
-                fwd.listen_path = packet_get_string(NULL);
+                if ((r = sshpkt_get_cstring(ssh, &fwd.listen_path, NULL)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: parse cancel-streamlocal-forward@openssh.com", __func__);
                 debug("%s: cancel-streamlocal-forward path %s", __func__,
                     fwd.listen_path);
 
                 success = channel_cancel_rport_listener(ssh, &fwd);
-                free(fwd.listen_path);
         } else if (strcmp(rtype, "no-more-sessions@openssh.com") == 0) {
                 no_more_sessions = 1;
                 success = 1;
         } else if (strcmp(rtype, "hostkeys-prove-00@openssh.com") == 0) {
                 success = server_input_hostkeys_prove(ssh, &resp);
         }
+        /* XXX sshpkt_get_end() */
         if (want_reply) {
-                packet_start(success ?
-                    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE);
-                if (success && resp != NULL)
-                        ssh_packet_put_raw(ssh, sshbuf_ptr(resp),
-                            sshbuf_len(resp));
-                packet_send();
-                packet_write_wait();
+                if ((r = sshpkt_start(ssh, success ?
+                    SSH2_MSG_REQUEST_SUCCESS : SSH2_MSG_REQUEST_FAILURE)) != 0 ||
+                    (success && resp != NULL && (r = sshpkt_putb(ssh, resp)) != 0) ||
+                    (r = sshpkt_send(ssh)) != 0 ||
+                    (r = ssh_packet_write_wait(ssh)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: send reply", __func__);
         }
+        free(fwd.listen_host);
+        free(fwd.listen_path);
         free(rtype);
         sshbuf_free(resp);
         return 0;
@@ -864,58 +919,64 @@ static int
 server_input_channel_req(int type, u_int32_t seq, struct ssh *ssh)
 {
         Channel *c;
-        int id, reply, success = 0;
-        char *rtype;
-
-        id = packet_get_int();
-        rtype = packet_get_string(NULL);
-        reply = packet_get_char();
-
-        debug("server_input_channel_req: channel %d request %s reply %d",
-            id, rtype, reply);
-
-        if ((c = channel_lookup(ssh, id)) == NULL)
-                packet_disconnect("server_input_channel_req: "
-                    "unknown channel %d", id);
+        int r, success = 0;
+        char *rtype = NULL;
+        u_char want_reply = 0;
+        u_int id = 0;
+
+        if ((r = sshpkt_get_u32(ssh, &id)) != 0 ||
+            (r = sshpkt_get_cstring(ssh, &rtype, NULL)) != 0 ||
+            (r = sshpkt_get_u8(ssh, &want_reply)) != 0)
+                sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
+
+        debug("server_input_channel_req: channel %u request %s reply %d",
+            id, rtype, want_reply);
+
+        if (id >= INT_MAX || (c = channel_lookup(ssh, (int)id)) == NULL) {
+                ssh_packet_disconnect(ssh, "%s: unknown channel %d",
+                    __func__, id);
+        }
         if (!strcmp(rtype, "eow@openssh.com")) {
-                packet_check_eom();
+                if ((r = sshpkt_get_end(ssh)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: parse packet", __func__);
                 chan_rcvd_eow(ssh, c);
         } else if ((c->type == SSH_CHANNEL_LARVAL ||
             c->type == SSH_CHANNEL_OPEN) && strcmp(c->ctype, "session") == 0)
                 success = session_input_channel_req(ssh, c, rtype);
-        if (reply && !(c->flags & CHAN_CLOSE_SENT)) {
+        if (want_reply && !(c->flags & CHAN_CLOSE_SENT)) {
                 if (!c->have_remote_id)
                         fatal("%s: channel %d: no remote_id",
                             __func__, c->self);
-                packet_start(success ?
-                    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE);
-                packet_put_int(c->remote_id);
-                packet_send();
+                if ((r = sshpkt_start(ssh, success ?
+                    SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE)) != 0 ||
+                    (r = sshpkt_put_u32(ssh, c->remote_id)) != 0 ||
+                    (r = sshpkt_send(ssh)) != 0)
+                        sshpkt_fatal(ssh, r, "%s: send reply", __func__);
         }
         free(rtype);
         return 0;
 }
 
 static void
-server_init_dispatch(void)
+server_init_dispatch(struct ssh *ssh)
 {
         debug("server_init_dispatch");
-        dispatch_init(&dispatch_protocol_error);
-        dispatch_set(SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
-        dispatch_set(SSH2_MSG_CHANNEL_DATA, &channel_input_data);
-        dispatch_set(SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
-        dispatch_set(SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
-        dispatch_set(SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
-        dispatch_set(SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
-        dispatch_set(SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
-        dispatch_set(SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
-        dispatch_set(SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
-        dispatch_set(SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
+        ssh_dispatch_init(ssh, &dispatch_protocol_error);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_CLOSE, &channel_input_oclose);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_DATA, &channel_input_data);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EOF, &channel_input_ieof);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_EXTENDED_DATA, &channel_input_extended_data);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN, &server_input_channel_open);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION, &channel_input_open_confirmation);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_OPEN_FAILURE, &channel_input_open_failure);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_REQUEST, &server_input_channel_req);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_WINDOW_ADJUST, &channel_input_window_adjust);
+        ssh_dispatch_set(ssh, SSH2_MSG_GLOBAL_REQUEST, &server_input_global_request);
         /* client_alive */
-        dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
-        dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
-        dispatch_set(SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
-        dispatch_set(SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_SUCCESS, &server_input_keep_alive);
+        ssh_dispatch_set(ssh, SSH2_MSG_CHANNEL_FAILURE, &server_input_keep_alive);
+        ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_SUCCESS, &server_input_keep_alive);
+        ssh_dispatch_set(ssh, SSH2_MSG_REQUEST_FAILURE, &server_input_keep_alive);
         /* rekeying */
-        dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+        ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
 }