]> andersk Git - gssapi-openssh.git/blobdiff - openssh/clientloop.c
http://www.sxw.org.uk/computing/patches/openssh-4.2p1-gsskex-20050926-2.patch
[gssapi-openssh.git] / openssh / clientloop.c
index 0b9a0fb29c82ce05b25a241be1721184faf18954..47f3c7ecd9bfd1ac844120e313d9d8771ed16c6a 100644 (file)
@@ -59,7 +59,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: clientloop.c,v 1.130 2004/08/11 21:43:04 avsm Exp $");
+RCSID("$OpenBSD: clientloop.c,v 1.141 2005/07/16 01:35:24 djm Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -140,6 +140,8 @@ int session_ident = -1;
 struct confirm_ctx {
        int want_tty;
        int want_subsys;
+       int want_x_fwd;
+       int want_agent_fwd;
        Buffer cmd;
        char *term;
        struct termios tio;
@@ -208,6 +210,109 @@ get_current_time(void)
        return (double) tv.tv_sec + (double) tv.tv_usec / 1000000.0;
 }
 
+#define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
+void
+client_x11_get_proto(const char *display, const char *xauth_path,
+    u_int trusted, char **_proto, char **_data)
+{
+       char cmd[1024];
+       char line[512];
+       char xdisplay[512];
+       static char proto[512], data[512];
+       FILE *f;
+       int got_data = 0, generated = 0, do_unlink = 0, i;
+       char *xauthdir, *xauthfile;
+       struct stat st;
+
+       xauthdir = xauthfile = NULL;
+       *_proto = proto;
+       *_data = data;
+       proto[0] = data[0] = '\0';
+
+       if (xauth_path == NULL ||(stat(xauth_path, &st) == -1)) {
+               debug("No xauth program.");
+       } else {
+               if (display == NULL) {
+                       debug("x11_get_proto: DISPLAY not set");
+                       return;
+               }
+               /*
+                * Handle FamilyLocal case where $DISPLAY does
+                * not match an authorization entry.  For this we
+                * just try "xauth list unix:displaynum.screennum".
+                * XXX: "localhost" match to determine FamilyLocal
+                *      is not perfect.
+                */
+               if (strncmp(display, "localhost:", 10) == 0) {
+                       snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
+                           display + 10);
+                       display = xdisplay;
+               }
+               if (trusted == 0) {
+                       xauthdir = xmalloc(MAXPATHLEN);
+                       xauthfile = xmalloc(MAXPATHLEN);
+                       strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
+                       if (mkdtemp(xauthdir) != NULL) {
+                               do_unlink = 1;
+                               snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
+                                   xauthdir);
+                               snprintf(cmd, sizeof(cmd),
+                                   "%s -f %s generate %s " SSH_X11_PROTO
+                                   " untrusted timeout 1200 2>" _PATH_DEVNULL,
+                                   xauth_path, xauthfile, display);
+                               debug2("x11_get_proto: %s", cmd);
+                               if (system(cmd) == 0)
+                                       generated = 1;
+                       }
+               }
+               snprintf(cmd, sizeof(cmd),
+                   "%s %s%s list %s . 2>" _PATH_DEVNULL,
+                   xauth_path,
+                   generated ? "-f " : "" ,
+                   generated ? xauthfile : "",
+                   display);
+               debug2("x11_get_proto: %s", cmd);
+               f = popen(cmd, "r");
+               if (f && fgets(line, sizeof(line), f) &&
+                   sscanf(line, "%*s %511s %511s", proto, data) == 2)
+                       got_data = 1;
+               if (f)
+                       pclose(f);
+       }
+
+       if (do_unlink) {
+               unlink(xauthfile);
+               rmdir(xauthdir);
+       }
+       if (xauthdir)
+               xfree(xauthdir);
+       if (xauthfile)
+               xfree(xauthfile);
+
+       /*
+        * If we didn't get authentication data, just make up some
+        * data.  The forwarding code will check the validity of the
+        * response anyway, and substitute this data.  The X11
+        * server, however, will ignore this fake data and use
+        * whatever authentication mechanisms it was using otherwise
+        * for the local connection.
+        */
+       if (!got_data) {
+               u_int32_t rnd = 0;
+
+               logit("Warning: No xauth data; "
+                   "using fake authentication data for X11 forwarding.");
+               strlcpy(proto, SSH_X11_PROTO, sizeof proto);
+               for (i = 0; i < 16; i++) {
+                       if (i % 4 == 0)
+                               rnd = arc4random();
+                       snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
+                           rnd & 0xff);
+                       rnd >>= 8;
+               }
+       }
+}
+
 /*
  * This is called when the interactive is entered.  This checks if there is
  * an EOF coming on stdin.  We must check this explicitly, as select() does
@@ -432,8 +537,6 @@ client_wait_until_can_do_something(fd_set **readsetp, fd_set **writesetp,
 static void
 client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
 {
-       struct winsize oldws, newws;
-
        /* Flush stdout and stderr buffers. */
        if (buffer_len(bout) > 0)
                atomicio(vwrite, fileno(stdout), buffer_ptr(bout), buffer_len(bout));
@@ -450,19 +553,11 @@ client_suspend_self(Buffer *bin, Buffer *bout, Buffer *berr)
        buffer_free(bout);
        buffer_free(berr);
 
-       /* Save old window size. */
-       ioctl(fileno(stdin), TIOCGWINSZ, &oldws);
-
        /* Send the suspend signal to the program itself. */
        kill(getpid(), SIGTSTP);
 
-       /* Check if the window size has changed. */
-       if (ioctl(fileno(stdin), TIOCGWINSZ, &newws) >= 0 &&
-           (oldws.ws_row != newws.ws_row ||
-           oldws.ws_col != newws.ws_col ||
-           oldws.ws_xpixel != newws.ws_xpixel ||
-           oldws.ws_ypixel != newws.ws_ypixel))
-               received_window_change_signal = 1;
+       /* Reset window sizes in case they have changed */
+       received_window_change_signal = 1;
 
        /* OK, we have been continued by the user. Reinitialize buffers. */
        buffer_init(bin);
@@ -538,6 +633,7 @@ static void
 client_extra_session2_setup(int id, void *arg)
 {
        struct confirm_ctx *cctx = arg;
+       const char *display;
        Channel *c;
        int i;
 
@@ -546,6 +642,24 @@ client_extra_session2_setup(int id, void *arg)
        if ((c = channel_lookup(id)) == NULL)
                fatal("%s: no channel for id %d", __func__, id);
 
+       display = getenv("DISPLAY");
+       if (cctx->want_x_fwd && options.forward_x11 && display != NULL) {
+               char *proto, *data;
+               /* Get reasonable local authentication information. */
+               client_x11_get_proto(display, options.xauth_location,
+                   options.forward_x11_trusted, &proto, &data);
+               /* Request forwarding with authentication spoofing. */
+               debug("Requesting X11 forwarding with authentication spoofing.");
+               x11_request_forwarding_with_spoofing(id, display, proto, data);
+               /* XXX wait for reply */
+       }
+
+       if (cctx->want_agent_fwd && options.forward_agent) {
+               debug("Requesting authentication agent forwarding.");
+               channel_request_start(id, "auth-agent-req@openssh.com", 0);
+               packet_send();
+       }
+
        client_session2_setup(id, cctx->want_tty, cctx->want_subsys,
            cctx->term, &cctx->tio, c->rfd, &cctx->cmd, cctx->env,
            client_subsystem_reply);
@@ -566,12 +680,12 @@ client_process_control(fd_set * readset)
 {
        Buffer m;
        Channel *c;
-       int client_fd, new_fd[3], ver, i, allowed;
+       int client_fd, new_fd[3], ver, allowed;
        socklen_t addrlen;
        struct sockaddr_storage addr;
        struct confirm_ctx *cctx;
        char *cmd;
-       u_int len, env_len;
+       u_int i, len, env_len, command, flags;
        uid_t euid;
        gid_t egid;
 
@@ -601,39 +715,76 @@ client_process_control(fd_set * readset)
                return;
        }
 
-       allowed = 1;
-       if (options.control_master == 2) {
-               char *p, prompt[1024];
-
-               allowed = 0;
-               snprintf(prompt, sizeof(prompt),
-                   "Allow shared connection to %s? ", host);
-               p = read_passphrase(prompt, RP_USE_ASKPASS|RP_ALLOW_EOF);
-               if (p != NULL) {
-                       /*
-                        * Accept empty responses and responses consisting
-                        * of the word "yes" as affirmative.
-                        */
-                       if (*p == '\0' || *p == '\n' ||
-                           strcasecmp(p, "yes") == 0)
-                               allowed = 1;
-                       xfree(p);
-               }
-       }
-
        unset_nonblock(client_fd);
 
+       /* Read command */
        buffer_init(&m);
+       if (ssh_msg_recv(client_fd, &m) == -1) {
+               error("%s: client msg_recv failed", __func__);
+               close(client_fd);
+               buffer_free(&m);
+               return;
+       }
+       if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
+               error("%s: wrong client version %d", __func__, ver);
+               buffer_free(&m);
+               close(client_fd);
+               return;
+       }
 
+       allowed = 1;
+       command = buffer_get_int(&m);
+       flags = buffer_get_int(&m);
+
+       buffer_clear(&m);
+
+       switch (command) {
+       case SSHMUX_COMMAND_OPEN:
+               if (options.control_master == SSHCTL_MASTER_ASK ||
+                   options.control_master == SSHCTL_MASTER_AUTO_ASK)
+                       allowed = ask_permission("Allow shared connection "
+                           "to %s? ", host);
+               /* continue below */
+               break;
+       case SSHMUX_COMMAND_TERMINATE:
+               if (options.control_master == SSHCTL_MASTER_ASK ||
+                   options.control_master == SSHCTL_MASTER_AUTO_ASK)
+                       allowed = ask_permission("Terminate shared connection "
+                           "to %s? ", host);
+               if (allowed)
+                       quit_pending = 1;
+               /* FALLTHROUGH */
+       case SSHMUX_COMMAND_ALIVE_CHECK:
+               /* Reply for SSHMUX_COMMAND_TERMINATE and ALIVE_CHECK */
+               buffer_clear(&m);
+               buffer_put_int(&m, allowed);
+               buffer_put_int(&m, getpid());
+               if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
+                       error("%s: client msg_send failed", __func__);
+                       close(client_fd);
+                       buffer_free(&m);
+                       return;
+               }
+               buffer_free(&m);
+               close(client_fd);
+               return;
+       default:
+               error("Unsupported command %d", command);
+               buffer_free(&m);
+               close(client_fd);
+               return;
+       }
+
+       /* Reply for SSHMUX_COMMAND_OPEN */
+       buffer_clear(&m);
        buffer_put_int(&m, allowed);
        buffer_put_int(&m, getpid());
-       if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
+       if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
                error("%s: client msg_send failed", __func__);
                close(client_fd);
                buffer_free(&m);
                return;
        }
-       buffer_clear(&m);
 
        if (!allowed) {
                error("Refused control connection");
@@ -642,14 +793,14 @@ client_process_control(fd_set * readset)
                return;
        }
 
+       buffer_clear(&m);
        if (ssh_msg_recv(client_fd, &m) == -1) {
                error("%s: client msg_recv failed", __func__);
                close(client_fd);
                buffer_free(&m);
                return;
        }
-
-       if ((ver = buffer_get_char(&m)) != 0) {
+       if ((ver = buffer_get_char(&m)) != SSHMUX_VER) {
                error("%s: wrong client version %d", __func__, ver);
                buffer_free(&m);
                close(client_fd);
@@ -658,9 +809,10 @@ client_process_control(fd_set * readset)
 
        cctx = xmalloc(sizeof(*cctx));
        memset(cctx, 0, sizeof(*cctx));
-
-       cctx->want_tty = buffer_get_int(&m);
-       cctx->want_subsys = buffer_get_int(&m);
+       cctx->want_tty = (flags & SSHMUX_FLAG_TTY) != 0;
+       cctx->want_subsys = (flags & SSHMUX_FLAG_SUBSYS) != 0;
+       cctx->want_x_fwd = (flags & SSHMUX_FLAG_X11_FWD) != 0;
+       cctx->want_agent_fwd = (flags & SSHMUX_FLAG_AGENT_FWD) != 0;
        cctx->term = buffer_get_string(&m, &len);
 
        cmd = buffer_get_string(&m, &len);
@@ -692,14 +844,21 @@ client_process_control(fd_set * readset)
        if (cctx->want_tty && tcgetattr(new_fd[0], &cctx->tio) == -1)
                error("%s: tcgetattr: %s", __func__, strerror(errno));
 
+       /* This roundtrip is just for synchronisation of ttymodes */
        buffer_clear(&m);
-       if (ssh_msg_send(client_fd, /* version */0, &m) == -1) {
+       if (ssh_msg_send(client_fd, SSHMUX_VER, &m) == -1) {
                error("%s: client msg_send failed", __func__);
                close(client_fd);
                close(new_fd[0]);
                close(new_fd[1]);
                close(new_fd[2]);
                buffer_free(&m);
+               xfree(cctx->term);
+               if (env_len != 0) {
+                       for (i = 0; i < env_len; i++)
+                               xfree(cctx->env[i]);
+                       xfree(cctx->env);
+               }
                return;
        }
        buffer_free(&m);
@@ -732,11 +891,11 @@ static void
 process_cmdline(void)
 {
        void (*handler)(int);
-       char *s, *cmd;
-       u_short fwd_port, fwd_host_port;
-       char buf[1024], sfwd_port[6], sfwd_host_port[6];
+       char *s, *cmd, *cancel_host;
        int delete = 0;
        int local = 0;
+       u_short cancel_port;
+       Forward fwd;
 
        leave_raw_mode();
        handler = signal(SIGINT, SIG_IGN);
@@ -782,37 +941,38 @@ process_cmdline(void)
                s++;
 
        if (delete) {
-               if (sscanf(s, "%5[0-9]", sfwd_host_port) != 1) {
-                       logit("Bad forwarding specification.");
-                       goto out;
+               cancel_port = 0;
+               cancel_host = hpdelim(&s);      /* may be NULL */
+               if (s != NULL) {
+                       cancel_port = a2port(s);
+                       cancel_host = cleanhostname(cancel_host);
+               } else {
+                       cancel_port = a2port(cancel_host);
+                       cancel_host = NULL;
                }
-               if ((fwd_host_port = a2port(sfwd_host_port)) == 0) {
-                       logit("Bad forwarding port(s).");
+               if (cancel_port == 0) {
+                       logit("Bad forwarding close port");
                        goto out;
                }
-               channel_request_rforward_cancel(fwd_host_port);
+               channel_request_rforward_cancel(cancel_host, cancel_port);
        } else {
-               if (sscanf(s, "%5[0-9]:%255[^:]:%5[0-9]",
-                   sfwd_port, buf, sfwd_host_port) != 3 &&
-                   sscanf(s, "%5[0-9]/%255[^/]/%5[0-9]",
-                   sfwd_port, buf, sfwd_host_port) != 3) {
+               if (!parse_forward(&fwd, s)) {
                        logit("Bad forwarding specification.");
                        goto out;
                }
-               if ((fwd_port = a2port(sfwd_port)) == 0 ||
-                   (fwd_host_port = a2port(sfwd_host_port)) == 0) {
-                       logit("Bad forwarding port(s).");
-                       goto out;
-               }
                if (local) {
-                       if (channel_setup_local_fwd_listener(fwd_port, buf,
-                           fwd_host_port, options.gateway_ports) < 0) {
+                       if (channel_setup_local_fwd_listener(fwd.listen_host,
+                           fwd.listen_port, fwd.connect_host,
+                           fwd.connect_port, options.gateway_ports) < 0) {
                                logit("Port forwarding failed.");
                                goto out;
                        }
-               } else
-                       channel_request_remote_forwarding(fwd_port, buf,
-                           fwd_host_port);
+               } else {
+                       channel_request_remote_forwarding(fwd.listen_host,
+                           fwd.listen_port, fwd.connect_host,
+                           fwd.connect_port);
+               }
+
                logit("Forwarding port.");
        }
 
@@ -834,7 +994,10 @@ process_escapes(Buffer *bin, Buffer *bout, Buffer *berr, char *buf, int len)
        u_char ch;
        char *s;
 
-       for (i = 0; i < len; i++) {
+       if (len <= 0)
+               return (0);
+
+       for (i = 0; i < (u_int)len; i++) {
                /* Get one character at a time. */
                ch = buf[i];
 
@@ -1196,14 +1359,15 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
         * Set signal handlers, (e.g. to restore non-blocking mode)
         * but don't overwrite SIG_IGN, matches behaviour from rsh(1)
         */
+       if (signal(SIGHUP, SIG_IGN) != SIG_IGN)
+               signal(SIGHUP, signal_handler);
        if (signal(SIGINT, SIG_IGN) != SIG_IGN)
                signal(SIGINT, signal_handler);
        if (signal(SIGQUIT, SIG_IGN) != SIG_IGN)
                signal(SIGQUIT, signal_handler);
        if (signal(SIGTERM, SIG_IGN) != SIG_IGN)
                signal(SIGTERM, signal_handler);
-       if (have_pty)
-               signal(SIGWINCH, window_change_handler);
+       signal(SIGWINCH, window_change_handler);
 
        if (have_pty)
                enter_raw_mode();
@@ -1311,8 +1475,7 @@ client_loop(int have_pty, int escape_char_arg, int ssh2_chan_id)
        /* Terminate the session. */
 
        /* Stop watching for window change. */
-       if (have_pty)
-               signal(SIGWINCH, SIG_DFL);
+       signal(SIGWINCH, SIG_DFL);
 
        channel_free_all();
 
@@ -1679,9 +1842,13 @@ client_session2_setup(int id, int want_tty, int want_subsystem,
     dispatch_fn *subsys_repl)
 {
        int len;
+       Channel *c = NULL;
 
        debug2("%s: id %d", __func__, id);
 
+       if ((c = channel_lookup(id)) == NULL)
+               fatal("client_session2_setup: channel %d: unknown channel", id);
+
        if (want_tty) {
                struct winsize ws;
                struct termios tio;
@@ -1700,6 +1867,7 @@ client_session2_setup(int id, int want_tty, int want_subsystem,
                tty_make_modes(-1, tiop != NULL ? tiop : &tio);
                packet_send();
                /* XXX wait for reply */
+               c->client_tty = 1;
        }
 
        /* Transfer any environment variables from client to server */
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