- markus@cvs.openbsd.org 2001/06/04 23:16:16

     [session.c]
     merge ssh1/2 x11-fwd setup, create listener after tmp-dir

1 files changed, 64 insertions, 95 deletions

diff --git a/session.c b/session.c
index c65c7e663..cedd8ad6f 100644
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.80 2001/06/04 21:59:43 markus Exp $");
+RCSID("$OpenBSD: session.c,v 1.81 2001/06/04 23:16:16 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -123,6 +123,7 @@ Session *session_new(void);
 void    session_set_fds(Session *s, int fdin, int fdout, int fderr);
 void    session_pty_cleanup(Session *s);
 void    session_proctitle(Session *s);
+int     session_setup_x11fwd(Session *s);
 void    do_exec_pty(Session *s, const char *command);
 void    do_exec_no_pty(Session *s, const char *command);
 void    do_login(Session *s, const char *command);
@@ -261,10 +262,9 @@ do_authenticated1(Authctxt *authctxt)
 {
         Session *s;
         char *command;
-        int success, type, fd, n_bytes, plen, screen_flag, have_pty = 0;
+        int success, type, n_bytes, plen, screen_flag, have_pty = 0;
         int compression_level = 0, enable_compression_after_reply = 0;
         u_int proto_len, data_len, dlen;
-        struct stat st;
 
         s = session_new();
         s->pw = authctxt->pw;
@@ -343,23 +343,6 @@ do_authenticated1(Authctxt *authctxt)
                         break;
 
                 case SSH_CMSG_X11_REQUEST_FORWARDING:
-                        if (!options.x11_forwarding) {
-                                packet_send_debug("X11 forwarding disabled in server configuration file.");
-                                break;
-                        }
-                        if (!options.xauth_location ||
-                            (stat(options.xauth_location, &st) == -1)) {
-                                packet_send_debug("No xauth program; cannot forward with spoofing.");
-                                break;
-                        }
-                        if (no_x11_forwarding_flag) {
-                                packet_send_debug("X11 forwarding not permitted for this authentication.");
-                                break;
-                        }
-                        debug("Received request for X11 forwarding with auth spoofing.");
-                        if (s->display != NULL)
-                                packet_disconnect("Protocol error: X11 display already set.");
-
                         s->auth_proto = packet_get_string(&proto_len);
                         s->auth_data = packet_get_string(&data_len);
 
@@ -371,39 +354,16 @@ do_authenticated1(Authctxt *authctxt)
                                 if (!screen_flag)
                                         debug2("Buggy client: "
                                             "X11 screen flag missing");
-                                packet_integrity_check(plen,
-                                    4 + proto_len + 4 + data_len + 4, type);
                                 s->screen = packet_get_int();
                         } else {
-                                packet_integrity_check(plen,
-                                    4 + proto_len + 4 + data_len, type);
                                 s->screen = 0;
                         }
-                        s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
-
-                        if (s->display == NULL)
-                                break;
-
-                        /* Setup to always have a local .Xauthority. */
-                        xauthfile = xmalloc(MAXPATHLEN);
-                        strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
-                        temporarily_use_uid(s->pw);
-                        if (mkdtemp(xauthfile) == NULL) {
-                                restore_uid();
-                                error("private X11 dir: mkdtemp %s failed: %s",
-                                    xauthfile, strerror(errno));
-                                xfree(xauthfile);
-                                xauthfile = NULL;
-                                /* XXXX remove listening channels */
-                                break;
+                        packet_done();
+                        success = session_setup_x11fwd(s);
+                        if (!success) {
+                                xfree(s->auth_proto);
+                                xfree(s->auth_data);
                         }
-                        strlcat(xauthfile, "/cookies", MAXPATHLEN);
-                        fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
-                        if (fd >= 0)
-                                close(fd);
-                        restore_uid();
-                        fatal_add_cleanup(xauthfile_cleanup_proc, s->pw);
-                        success = 1;
                         break;
 
                 case SSH_CMSG_AGENT_REQUEST_FORWARDING:
@@ -1759,29 +1719,7 @@ session_subsystem_req(Session *s)
 int
 session_x11_req(Session *s)
 {
-        int fd;
-        struct stat st;
-        if (no_x11_forwarding_flag) {
-                debug("X11 forwarding disabled in user configuration file.");
-                return 0;
-        }
-        if (!options.x11_forwarding) {
-                debug("X11 forwarding disabled in server configuration file.");
-                return 0;
-        }
-        if (!options.xauth_location ||
-            (stat(options.xauth_location, &st) == -1)) {
-                packet_send_debug("No xauth program; cannot forward with spoofing.");
-                return 0;
-        }
-        if (xauthfile != NULL) {
-                debug("X11 fwd already started.");
-                return 0;
-        }
-
-        debug("Received request for X11 forwarding with auth spoofing.");
-        if (s->display != NULL)
-                packet_disconnect("Protocol error: X11 display already set.");
+        int success;
 
         s->single_connection = packet_get_char();
         s->auth_proto = packet_get_string(NULL);
@@ -1789,33 +1727,12 @@ session_x11_req(Session *s)
         s->screen = packet_get_int();
         packet_done();
 
-        s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
-        if (s->display == NULL) {
+        success = session_setup_x11fwd(s);
+        if (!success) {
                 xfree(s->auth_proto);
                 xfree(s->auth_data);
-                return 0;
         }
-        xauthfile = xmalloc(MAXPATHLEN);
-        strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
-        temporarily_use_uid(s->pw);
-        if (mkdtemp(xauthfile) == NULL) {
-                restore_uid();
-                error("private X11 dir: mkdtemp %s failed: %s",
-                    xauthfile, strerror(errno));
-                xfree(xauthfile);
-                xauthfile = NULL;
-                xfree(s->auth_proto);
-                xfree(s->auth_data);
-                /* XXXX remove listening channels */
-                return 0;
-        }
-        strlcat(xauthfile, "/cookies", MAXPATHLEN);
-        fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
-        if (fd >= 0)
-                close(fd);
-        restore_uid();
-        fatal_add_cleanup(xauthfile_cleanup_proc, s->pw);
-        return 1;
+        return success;
 }
 
 int
@@ -2033,6 +1950,10 @@ session_free(Session *s)
 void
 session_close(Session *s)
 {
+        if (s->display) {
+                xauthfile_cleanup_proc(s->pw);
+                fatal_remove_cleanup(xauthfile_cleanup_proc, s->pw);
+        }
         session_pty_cleanup(s);
         session_free(s);
         session_proctitle(s);
@@ -2107,6 +2028,54 @@ session_proctitle(Session *s)
                 setproctitle("%s@%s", s->pw->pw_name, session_tty_list());
 }
 
+int
+session_setup_x11fwd(Session *s)
+{
+        int fd;
+        struct stat st;
+
+        if (no_x11_forwarding_flag) {
+                packet_send_debug("X11 forwarding disabled in user configuration file.");
+                return 0;
+        }
+        if (!options.x11_forwarding) {
+                debug("X11 forwarding disabled in server configuration file.");
+                return 0;
+        }
+        if (!options.xauth_location ||
+            (stat(options.xauth_location, &st) == -1)) {
+                packet_send_debug("No xauth program; cannot forward with spoofing.");
+                return 0;
+        }
+        if (s->display != NULL) {
+                debug("X11 display already set.");
+                return 0;
+        }
+        xauthfile = xmalloc(MAXPATHLEN);
+        strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
+        temporarily_use_uid(s->pw);
+        if (mkdtemp(xauthfile) == NULL) {
+                restore_uid();
+                error("private X11 dir: mkdtemp %s failed: %s",
+                    xauthfile, strerror(errno));
+                xfree(xauthfile);
+                xauthfile = NULL;
+                return 0;
+        }
+        strlcat(xauthfile, "/cookies", MAXPATHLEN);
+        fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600);
+        if (fd >= 0)
+                close(fd);
+        restore_uid();
+        s->display = x11_create_display_inet(s->screen, options.x11_display_offset);
+        if (s->display == NULL) {
+                xauthfile_cleanup_proc(s->pw);
+                return 0;
+        }
+        fatal_add_cleanup(xauthfile_cleanup_proc, s->pw);
+        return 1;
+}
+
 void
 do_authenticated2(Authctxt *authctxt)
 {