]> andersk Git - openssh.git/blobdiff - session.c
- (tim) [kex.c myproposal.h md-sha256.c openbsd-compat/sha2.c,h] Disable
[openssh.git] / session.c
index cf2098931a93e49f863344c821b9ec41145172f4..8eb1a03e574d9ff708c02f9e1620d21364048504 100644 (file)
--- a/session.c
+++ b/session.c
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.177 2004/06/30 08:36:59 djm Exp $");
+RCSID("$OpenBSD: session.c,v 1.197 2006/02/28 01:10:21 djm Exp $");
+
+#include <sys/types.h>
+#ifdef HAVE_SYS_STAT_H
+# include <sys/stat.h>
+#endif
+#include <sys/wait.h>
+#include <sys/un.h>
+
+#ifdef HAVE_PATHS_H
+#include <paths.h>
+#endif
+#include <signal.h>
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -56,6 +68,7 @@ RCSID("$OpenBSD: session.c,v 1.177 2004/06/30 08:36:59 djm Exp $");
 #include "serverloop.h"
 #include "canohost.h"
 #include "session.h"
+#include "kex.h"
 #include "monitor_wrap.h"
 
 #if defined(KRB5) && defined(USE_AFS)
@@ -198,10 +211,9 @@ display_loginmsg(void)
 {
        if (buffer_len(&loginmsg) > 0) {
                buffer_append(&loginmsg, "\0", 1);
-               printf("%s\n", (char *)buffer_ptr(&loginmsg));
+               printf("%s", (char *)buffer_ptr(&loginmsg));
                buffer_clear(&loginmsg);
        }
-       fflush(stdout);
 }
 
 void
@@ -209,15 +221,6 @@ do_authenticated(Authctxt *authctxt)
 {
        setproctitle("%s", authctxt->pw->pw_name);
 
-       /*
-        * Cancel the alarm we set to limit the time taken for
-        * authentication.
-        */
-       alarm(0);
-       if (startup_pipe != -1) {
-               close(startup_pipe);
-               startup_pipe = -1;
-       }
        /* setup the channel layer */
        if (!no_port_forwarding_flag && options.allow_tcp_forwarding)
                channel_permit_all_opens();
@@ -246,6 +249,10 @@ do_authenticated1(Authctxt *authctxt)
        u_int proto_len, data_len, dlen, compression_level = 0;
 
        s = session_new();
+       if (s == NULL) {
+               error("no more sessions");
+               return;
+       }
        s->authctxt = authctxt;
        s->pw = authctxt->pw;
 
@@ -265,11 +272,11 @@ do_authenticated1(Authctxt *authctxt)
                        compression_level = packet_get_int();
                        packet_check_eom();
                        if (compression_level < 1 || compression_level > 9) {
-                               packet_send_debug("Received illegal compression level %d.",
+                               packet_send_debug("Received invalid compression level %d.",
                                    compression_level);
                                break;
                        }
-                       if (!options.compression) {
+                       if (options.compression == COMP_NONE) {
                                debug2("compression disabled");
                                break;
                        }
@@ -662,11 +669,15 @@ do_exec(Session *s, const char *command)
                debug("Forced command '%.900s'", command);
        }
 
-#ifdef GSSAPI
-       if (options.gss_authentication) {
-               temporarily_use_uid(s->pw);
-               ssh_gssapi_storecreds();
-               restore_uid();
+#ifdef SSH_AUDIT_EVENTS
+       if (command != NULL)
+               PRIVSEP(audit_run_command(command));
+       else if (s->ttyfd == -1) {
+               char *shell = s->pw->pw_shell;
+
+               if (shell[0] == '\0')   /* empty shell means /bin/sh */
+                       shell =_PATH_BSHELL;
+               PRIVSEP(audit_run_command(shell));
        }
 #endif
 
@@ -676,14 +687,19 @@ do_exec(Session *s, const char *command)
                do_exec_no_pty(s, command);
 
        original_command = NULL;
-}
 
+       /*
+        * Clear loginmsg: it's the child's responsibility to display
+        * it to the user, otherwise multiple sessions may accumulate
+        * multiple copies of the login messages.
+        */
+       buffer_clear(&loginmsg);
+}
 
 /* administrative, login(1)-like work */
 void
 do_login(Session *s, const char *command)
 {
-       char *time_string;
        socklen_t fromlen;
        struct sockaddr_storage from;
        struct passwd * pw = s->pw;
@@ -728,19 +744,6 @@ do_login(Session *s, const char *command)
 
        display_loginmsg();
 
-#ifndef NO_SSH_LASTLOG
-       if (options.print_lastlog && s->last_login_time != 0) {
-               time_string = ctime(&s->last_login_time);
-               if (strchr(time_string, '\n'))
-                       *strchr(time_string, '\n') = 0;
-               if (strcmp(s->hostname, "") == 0)
-                       printf("Last login: %s\r\n", time_string);
-               else
-                       printf("Last login: %s from %s\r\n", time_string,
-                           s->hostname);
-       }
-#endif /* NO_SSH_LASTLOG */
-
        do_motd();
 }
 
@@ -947,7 +950,8 @@ read_etc_default_login(char ***env, u_int *envsize, uid_t uid)
 }
 #endif /* HAVE_ETC_DEFAULT_LOGIN */
 
-void copy_environment(char **source, char ***env, u_int *envsize)
+void
+copy_environment(char **source, char ***env, u_int *envsize)
 {
        char *var_name, *var_val;
        int i;
@@ -988,7 +992,13 @@ do_setup_env(Session *s, const char *shell)
         * The Windows environment contains some setting which are
         * important for a running system. They must not be dropped.
         */
-       copy_environment(environ, &env, &envsize);
+       {
+               char **p;
+
+               p = fetch_windows_environment();
+               copy_environment(p, &env, &envsize);
+               free_windows_environment(p);
+       }
 #endif
 
 #ifdef GSSAPI
@@ -1001,7 +1011,7 @@ do_setup_env(Session *s, const char *shell)
        if (!options.use_login) {
                /* Set basic environment. */
                for (i = 0; i < s->num_env; i++)
-                       child_set_env(&env, &envsize, s->env[i].name, 
+                       child_set_env(&env, &envsize, s->env[i].name,
                            s->env[i].val);
 
                child_set_env(&env, &envsize, "USER", pw->pw_name);
@@ -1089,14 +1099,24 @@ do_setup_env(Session *s, const char *shell)
                child_set_env(&env, &envsize, "TMPDIR", cray_tmpdir);
 #endif /* _UNICOS */
 
+       /*
+        * Since we clear KRB5CCNAME at startup, if it's set now then it
+        * must have been set by a native authentication method (eg AIX or
+        * SIA), so copy it to the child.
+        */
+       {
+               char *cp;
+
+               if ((cp = getenv("KRB5CCNAME")) != NULL)
+                       child_set_env(&env, &envsize, "KRB5CCNAME", cp);
+       }
+
 #ifdef _AIX
        {
                char *cp;
 
                if ((cp = getenv("AUTHSTATE")) != NULL)
                        child_set_env(&env, &envsize, "AUTHSTATE", cp);
-               if ((cp = getenv("KRB5CCNAME")) != NULL)
-                       child_set_env(&env, &envsize, "KRB5CCNAME", cp);
                read_environment_file(&env, &envsize, "/etc/environment");
        }
 #endif
@@ -1256,6 +1276,13 @@ do_setusercontext(struct passwd *pw)
 # ifdef __bsdi__
                setpgid(0, 0);
 # endif
+#ifdef GSSAPI
+               if (options.gss_authentication) {
+                       temporarily_use_uid(pw);
+                       ssh_gssapi_storecreds();
+                       restore_uid();
+               }
+#endif
 # ifdef USE_PAM
                if (options.use_pam) {
                        do_pam_session();
@@ -1286,6 +1313,13 @@ do_setusercontext(struct passwd *pw)
                        exit(1);
                }
                endgrent();
+#ifdef GSSAPI
+               if (options.gss_authentication) {
+                       temporarily_use_uid(pw);
+                       ssh_gssapi_storecreds();
+                       restore_uid();
+               }
+#endif
 # ifdef USE_PAM
                /*
                 * PAM credentials may take the form of supplementary groups.
@@ -1303,6 +1337,11 @@ do_setusercontext(struct passwd *pw)
 # ifdef _AIX
                aix_usrinfo(pw);
 # endif /* _AIX */
+#if defined(HAVE_LIBIAF)  &&  !defined(BROKEN_LIBIAF)
+               if (set_id(pw->pw_name) != 0) {
+                       exit(1);
+               }
+#endif /* HAVE_LIBIAF  && !BROKEN_LIBIAF */
                /* Permanently switch to the desired uid. */
                permanently_set_uid(pw);
 #endif
@@ -1318,11 +1357,17 @@ do_setusercontext(struct passwd *pw)
 static void
 do_pwchange(Session *s)
 {
+       fflush(NULL);
        fprintf(stderr, "WARNING: Your password has expired.\n");
        if (s->ttyfd != -1) {
-               fprintf(stderr,
+               fprintf(stderr,
                    "You must change your password now and login again!\n");
+#ifdef PASSWD_NEEDS_USERNAME
+               execl(_PATH_PASSWD_PROG, "passwd", s->pw->pw_name,
+                   (char *)NULL);
+#else
                execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL);
+#endif
                perror("passwd");
        } else {
                fprintf(stderr,
@@ -1377,7 +1422,7 @@ child_close_fds(void)
        endpwent();
 
        /*
-        * Close any extra open file descriptors so that we don\'t have them
+        * Close any extra open file descriptors so that we don't have them
         * hanging around in clients.  Note that we want to do this after
         * initgroups, because at least on Solaris 2.3 it leaves file
         * descriptors open.
@@ -1429,11 +1474,28 @@ do_child(Session *s, const char *command)
                if (!check_quietlogin(s, command))
                        do_motd();
 #else /* HAVE_OSF_SIA */
-               do_nologin(pw);
+               /* When PAM is enabled we rely on it to do the nologin check */
+               if (!options.use_pam)
+                       do_nologin(pw);
                do_setusercontext(pw);
+               /*
+                * PAM session modules in do_setusercontext may have
+                * generated messages, so if this in an interactive
+                * login then display them too.
+                */
+               if (!check_quietlogin(s, command))
+                       display_loginmsg();
 #endif /* HAVE_OSF_SIA */
        }
 
+#ifdef USE_PAM
+       if (options.use_pam && !options.use_login && !is_pam_session_open()) {
+               debug3("PAM session not opened, exiting");
+               display_loginmsg();
+               exit(254);
+       }
+#endif
+
        /*
         * Get the shell from the password data.  An empty shell field is
         * legal, and means /bin/sh.
@@ -1479,7 +1541,7 @@ do_child(Session *s, const char *command)
         */
 
        if (options.kerberos_get_afs_token && k_hasafs() &&
-            (s->authctxt->krb5_ctx != NULL)) {
+           (s->authctxt->krb5_ctx != NULL)) {
                char cell[64];
 
                debug("Getting AFS token");
@@ -1495,7 +1557,7 @@ do_child(Session *s, const char *command)
        }
 #endif
 
-       /* Change current directory to the user\'s home directory. */
+       /* Change current directory to the user's home directory. */
        if (chdir(pw->pw_dir) < 0) {
                fprintf(stderr, "Could not chdir to home directory %s: %s\n",
                    pw->pw_dir, strerror(errno));
@@ -1583,6 +1645,7 @@ session_new(void)
                        s->ttyfd = -1;
                        s->used = 1;
                        s->self = i;
+                       s->x11_chanids = NULL;
                        debug("session_new: session %d", i);
                        return s;
                }
@@ -1655,6 +1718,29 @@ session_by_channel(int id)
        return NULL;
 }
 
+static Session *
+session_by_x11_channel(int id)
+{
+       int i, j;
+
+       for (i = 0; i < MAX_SESSIONS; i++) {
+               Session *s = &sessions[i];
+
+               if (s->x11_chanids == NULL || !s->used)
+                       continue;
+               for (j = 0; s->x11_chanids[j] != -1; j++) {
+                       if (s->x11_chanids[j] == id) {
+                               debug("session_by_x11_channel: session %d "
+                                   "channel %d", s->self, id);
+                               return s;
+                       }
+               }
+       }
+       debug("session_by_x11_channel: unknown channel %d", id);
+       session_dump();
+       return NULL;
+}
+
 static Session *
 session_by_pid(pid_t pid)
 {
@@ -1696,12 +1782,6 @@ session_pty_req(Session *s)
                packet_disconnect("Protocol error: you already have a pty.");
                return 0;
        }
-       /* Get the time and hostname when the user last logged in. */
-       if (options.print_lastlog) {
-               s->hostname[0] = '\0';
-               s->last_login_time = get_last_login_time(s->pw->pw_uid,
-                   s->pw->pw_name, s->hostname, sizeof(s->hostname));
-       }
 
        s->term = packet_get_string(&len);
 
@@ -1756,7 +1836,7 @@ session_subsystem_req(Session *s)
        u_int len;
        int success = 0;
        char *cmd, *subsys = packet_get_string(&len);
-       int i;
+       u_int i;
 
        packet_check_eom();
        logit("subsystem request for %.100s", subsys);
@@ -1790,6 +1870,11 @@ session_x11_req(Session *s)
 {
        int success;
 
+       if (s->auth_proto != NULL || s->auth_data != NULL) {
+               error("session_x11_req: session %d: "
+                   "x11 forwarding already active", s->self);
+               return 0;
+       }
        s->single_connection = packet_get_char();
        s->auth_proto = packet_get_string(NULL);
        s->auth_data = packet_get_string(NULL);
@@ -2014,6 +2099,62 @@ sig2name(int sig)
        return "SIG@openssh.com";
 }
 
+static void
+session_close_x11(int id)
+{
+       Channel *c;
+
+       if ((c = channel_by_id(id)) == NULL) {
+               debug("session_close_x11: x11 channel %d missing", id);
+       } else {
+               /* Detach X11 listener */
+               debug("session_close_x11: detach x11 channel %d", id);
+               channel_cancel_cleanup(id);
+               if (c->ostate != CHAN_OUTPUT_CLOSED)
+                       chan_mark_dead(c);
+       }
+}
+
+static void
+session_close_single_x11(int id, void *arg)
+{
+       Session *s;
+       u_int i;
+
+       debug3("session_close_single_x11: channel %d", id);
+       channel_cancel_cleanup(id);
+       if ((s  = session_by_x11_channel(id)) == NULL)
+               fatal("session_close_single_x11: no x11 channel %d", id);
+       for (i = 0; s->x11_chanids[i] != -1; i++) {
+               debug("session_close_single_x11: session %d: "
+                   "closing channel %d", s->self, s->x11_chanids[i]);
+               /*
+                * The channel "id" is already closing, but make sure we
+                * close all of its siblings.
+                */
+               if (s->x11_chanids[i] != id)
+                       session_close_x11(s->x11_chanids[i]);
+       }
+       xfree(s->x11_chanids);
+       s->x11_chanids = NULL;
+       if (s->display) {
+               xfree(s->display);
+               s->display = NULL;
+       }
+       if (s->auth_proto) {
+               xfree(s->auth_proto);
+               s->auth_proto = NULL;
+       }
+       if (s->auth_data) {
+               xfree(s->auth_data);
+               s->auth_data = NULL;
+       }
+       if (s->auth_display) {
+               xfree(s->auth_display);
+               s->auth_display = NULL;
+       }
+}
+
 static void
 session_exit_message(Session *s, int status)
 {
@@ -2047,7 +2188,14 @@ session_exit_message(Session *s, int status)
 
        /* disconnect channel */
        debug("session_exit_message: release channel %d", s->chanid);
-       channel_cancel_cleanup(s->chanid);
+
+       /*
+        * Adjust cleanup callback attachment to send close messages when
+        * the channel gets EOF. The session will be then be closed 
+        * by session_close_by_channel when the childs close their fds.
+        */
+       channel_register_cleanup(c->self, session_close_by_channel, 1);
+
        /*
         * emulate a write failure with 'chan_write_failed', nobody will be
         * interested in data we write.
@@ -2056,13 +2204,12 @@ session_exit_message(Session *s, int status)
         */
        if (c->ostate != CHAN_OUTPUT_CLOSED)
                chan_write_failed(c);
-       s->chanid = -1;
 }
 
 void
 session_close(Session *s)
 {
-       int i;
+       u_int i;
 
        debug("session_close: session %d pid %ld", s->self, (long)s->pid);
        if (s->ttyfd != -1)
@@ -2071,6 +2218,8 @@ session_close(Session *s)
                xfree(s->term);
        if (s->display)
                xfree(s->display);
+       if (s->x11_chanids)
+               xfree(s->x11_chanids);
        if (s->auth_display)
                xfree(s->auth_display);
        if (s->auth_data)
@@ -2098,7 +2247,9 @@ session_close_by_pid(pid_t pid, int status)
        }
        if (s->chanid != -1)
                session_exit_message(s, status);
-       session_close(s);
+       if (s->ttyfd != -1)
+               session_pty_cleanup(s);
+       s->pid = 0;
 }
 
 /*
@@ -2109,6 +2260,8 @@ void
 session_close_by_channel(int id, void *arg)
 {
        Session *s = session_by_channel(id);
+       u_int i;
+
        if (s == NULL) {
                debug("session_close_by_channel: no session for id %d", id);
                return;
@@ -2127,6 +2280,15 @@ session_close_by_channel(int id, void *arg)
        }
        /* detach by removing callback */
        channel_cancel_cleanup(s->chanid);
+
+       /* Close any X11 listeners associated with this session */
+       if (s->x11_chanids != NULL) {
+               for (i = 0; s->x11_chanids[i] != -1; i++) {
+                       session_close_x11(s->x11_chanids[i]);
+                       s->x11_chanids[i] = -1;
+               }
+       }
+
        s->chanid = -1;
        session_close(s);
 }
@@ -2189,6 +2351,7 @@ session_setup_x11fwd(Session *s)
        struct stat st;
        char display[512], auth_display[512];
        char hostname[MAXHOSTNAMELEN];
+       u_int i;
 
        if (no_x11_forwarding_flag) {
                packet_send_debug("X11 forwarding disabled in user configuration file.");
@@ -2214,10 +2377,14 @@ session_setup_x11fwd(Session *s)
        }
        if (x11_create_display_inet(options.x11_display_offset,
            options.x11_use_localhost, s->single_connection,
-           &s->display_number) == -1) {
+           &s->display_number, &s->x11_chanids) == -1) {
                debug("x11_create_display_inet failed.");
                return 0;
        }
+       for (i = 0; s->x11_chanids[i] != -1; i++) {
+               channel_register_cleanup(s->x11_chanids[i],
+                   session_close_single_x11, 0);
+       }
 
        /* Set up a suitable value for the DISPLAY variable. */
        if (gethostname(hostname, sizeof(hostname)) < 0)
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