]> andersk Git - openssh.git/blobdiff - session.c
- stevesk@cvs.openbsd.org 2002/08/08 23:54:52
[openssh.git] / session.c
index dcecf1ae34c115d1ba3036450ccdbe692970c349..f2a1bf015863eba487b20b5959e1b8dd6a28d3c4 100644 (file)
--- a/session.c
+++ b/session.c
@@ -33,7 +33,7 @@
  */
 
 #include "includes.h"
-RCSID("$OpenBSD: session.c,v 1.135 2002/05/16 22:09:59 stevesk Exp $");
+RCSID("$OpenBSD: session.c,v 1.146 2002/07/30 17:03:55 markus Exp $");
 
 #include "ssh.h"
 #include "ssh1.h"
@@ -111,6 +111,93 @@ char *aixloginmsg;
 login_cap_t *lc;
 #endif
 
+/* Name and directory of socket for authentication agent forwarding. */
+static char *auth_sock_name = NULL;
+static char *auth_sock_dir = NULL;
+
+/* removes the agent forwarding socket */
+
+static void
+auth_sock_cleanup_proc(void *_pw)
+{
+       struct passwd *pw = _pw;
+
+       if (auth_sock_name != NULL) {
+               temporarily_use_uid(pw);
+               unlink(auth_sock_name);
+               rmdir(auth_sock_dir);
+               auth_sock_name = NULL;
+               restore_uid();
+       }
+}
+
+static int
+auth_input_request_forwarding(struct passwd * pw)
+{
+       Channel *nc;
+       int sock;
+       struct sockaddr_un sunaddr;
+
+       if (auth_sock_name != NULL) {
+               error("authentication forwarding requested twice.");
+               return 0;
+       }
+
+       /* Temporarily drop privileged uid for mkdir/bind. */
+       temporarily_use_uid(pw);
+
+       /* Allocate a buffer for the socket name, and format the name. */
+       auth_sock_name = xmalloc(MAXPATHLEN);
+       auth_sock_dir = xmalloc(MAXPATHLEN);
+       strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXX", MAXPATHLEN);
+
+       /* Create private directory for socket */
+       if (mkdtemp(auth_sock_dir) == NULL) {
+               packet_send_debug("Agent forwarding disabled: "
+                   "mkdtemp() failed: %.100s", strerror(errno));
+               restore_uid();
+               xfree(auth_sock_name);
+               xfree(auth_sock_dir);
+               auth_sock_name = NULL;
+               auth_sock_dir = NULL;
+               return 0;
+       }
+       snprintf(auth_sock_name, MAXPATHLEN, "%s/agent.%ld",
+                auth_sock_dir, (long) getpid());
+
+       /* delete agent socket on fatal() */
+       fatal_add_cleanup(auth_sock_cleanup_proc, pw);
+
+       /* Create the socket. */
+       sock = socket(AF_UNIX, SOCK_STREAM, 0);
+       if (sock < 0)
+               packet_disconnect("socket: %.100s", strerror(errno));
+
+       /* Bind it to the name. */
+       memset(&sunaddr, 0, sizeof(sunaddr));
+       sunaddr.sun_family = AF_UNIX;
+       strlcpy(sunaddr.sun_path, auth_sock_name, sizeof(sunaddr.sun_path));
+
+       if (bind(sock, (struct sockaddr *) & sunaddr, sizeof(sunaddr)) < 0)
+               packet_disconnect("bind: %.100s", strerror(errno));
+
+       /* Restore the privileged uid. */
+       restore_uid();
+
+       /* Start listening on the socket. */
+       if (listen(sock, 5) < 0)
+               packet_disconnect("listen: %.100s", strerror(errno));
+
+       /* Allocate a channel for the authentication agent socket. */
+       nc = channel_new("auth socket",
+           SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1,
+           CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT,
+           0, xstrdup("auth socket"), 1);
+       strlcpy(nc->path, auth_sock_name, sizeof(nc->path));
+       return 1;
+}
+
+
 void
 do_authenticated(Authctxt *authctxt)
 {
@@ -141,7 +228,7 @@ do_authenticated(Authctxt *authctxt)
                do_authenticated1(authctxt);
 
        /* remove agent socket */
-       if (auth_get_socket_name())
+       if (auth_sock_name != NULL)
                auth_sock_cleanup_proc(authctxt->pw);
 #ifdef KRB4
        if (options.kerberos_ticket_cleanup)
@@ -165,8 +252,8 @@ do_authenticated1(Authctxt *authctxt)
        Session *s;
        char *command;
        int success, type, screen_flag;
-       int compression_level = 0, enable_compression_after_reply = 0;
-       u_int proto_len, data_len, dlen;
+       int enable_compression_after_reply = 0;
+       u_int proto_len, data_len, dlen, compression_level = 0;
 
        s = session_new();
        s->authctxt = authctxt;
@@ -192,6 +279,10 @@ do_authenticated1(Authctxt *authctxt)
                                    compression_level);
                                break;
                        }
+                       if (!options.compression) {
+                               debug2("compression disabled");
+                               break;
+                       }
                        /* Enable compression after we have responded with SUCCESS. */
                        enable_compression_after_reply = 1;
                        success = 1;
@@ -348,7 +439,7 @@ do_authenticated1(Authctxt *authctxt)
 void
 do_exec_no_pty(Session *s, const char *command)
 {
-       int pid;
+       pid_t pid;
 
 #ifdef USE_PIPES
        int pin[2], pout[2], perr[2];
@@ -379,6 +470,8 @@ do_exec_no_pty(Session *s, const char *command)
 
        /* Fork the child. */
        if ((pid = fork()) == 0) {
+               fatal_remove_all_cleanups();
+
                /* Child.  Reinitialize the log since the pid has changed. */
                log_init(__progname, options.log_level, options.log_facility, log_stderr);
 
@@ -494,6 +587,7 @@ do_exec_pty(Session *s, const char *command)
 
        /* Fork the child. */
        if ((pid = fork()) == 0) {
+               fatal_remove_all_cleanups();
 
                /* Child.  Reinitialize the log because the pid has changed. */
                log_init(__progname, options.log_level, options.log_facility, log_stderr);
@@ -758,6 +852,9 @@ child_set_env(char ***envp, u_int *envsizep, const char *name,
        } else {
                /* New variable.  Expand if necessary. */
                if (i >= (*envsizep) - 1) {
+                       if (*envsizep >= 1000)
+                               fatal("child_set_env: too many env vars,"
+                                   " skipping: %.100s", name);
                        (*envsizep) += 50;
                        env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
                }
@@ -783,12 +880,15 @@ read_environment_file(char ***env, u_int *envsize,
        FILE *f;
        char buf[4096];
        char *cp, *value;
+       u_int lineno = 0;
 
        f = fopen(filename, "r");
        if (!f)
                return;
 
        while (fgets(buf, sizeof(buf), f)) {
+               if (++lineno > 1000)
+                       fatal("Too many lines in environment file %s", filename);
                for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
                        ;
                if (!*cp || *cp == '#' || *cp == '\n')
@@ -797,7 +897,8 @@ read_environment_file(char ***env, u_int *envsize,
                        *strchr(cp, '\n') = '\0';
                value = strchr(cp, '=');
                if (value == NULL) {
-                       fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
+                       fprintf(stderr, "Bad line %u in %.100s\n", lineno,
+                           filename);
                        continue;
                }
                /*
@@ -861,8 +962,10 @@ do_setup_env(Session *s, const char *shell)
                child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
                child_set_env(&env, &envsize, "HOME", pw->pw_dir);
 #ifdef HAVE_LOGIN_CAP
-               (void) setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH);
-               child_set_env(&env, &envsize, "PATH", getenv("PATH"));
+               if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0)
+                       child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
+               else
+                       child_set_env(&env, &envsize, "PATH", getenv("PATH"));
 #else /* HAVE_LOGIN_CAP */
 # ifndef HAVE_CYGWIN
                /*
@@ -894,13 +997,13 @@ do_setup_env(Session *s, const char *shell)
        if (!options.use_login) {
                while (custom_environment) {
                        struct envstring *ce = custom_environment;
-                       char *s = ce->s;
+                       char *str = ce->s;
 
-                       for (i = 0; s[i] != '=' && s[i]; i++)
+                       for (i = 0; str[i] != '=' && str[i]; i++)
                                ;
-                       if (s[i] == '=') {
-                               s[i] = 0;
-                               child_set_env(&env, &envsize, s, s + i + 1);
+                       if (str[i] == '=') {
+                               str[i] = 0;
+                               child_set_env(&env, &envsize, str, str + i + 1);
                        }
                        custom_environment = ce->next;
                        xfree(ce->s);
@@ -944,16 +1047,25 @@ do_setup_env(Session *s, const char *shell)
                    s->authctxt->krb5_ticket_file);
 #endif
 #ifdef USE_PAM
-       /* Pull in any environment variables that may have been set by PAM. */
-       copy_environment(fetch_pam_environment(), &env, &envsize);
+       /*
+        * Pull in any environment variables that may have
+        * been set by PAM.
+        */
+       {
+               char **p;
+
+               p = fetch_pam_environment();
+               copy_environment(p, &env, &envsize);
+               free_pam_environment(p);
+       }
 #endif /* USE_PAM */
 
-       if (auth_get_socket_name() != NULL)
+       if (auth_sock_name != NULL)
                child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME,
-                   auth_get_socket_name());
+                   auth_sock_name);
 
        /* read $HOME/.ssh/environment. */
-       if (!options.use_login) {
+       if (options.permit_user_env && !options.use_login) {
                snprintf(buf, sizeof buf, "%.200s/.ssh/environment",
                    pw->pw_dir);
                read_environment_file(&env, &envsize, buf);
@@ -1066,10 +1178,13 @@ do_setusercontext(struct passwd *pw)
 #else /* HAVE_CYGWIN */
        if (getuid() == 0 || geteuid() == 0) {
 #endif /* HAVE_CYGWIN */
-#ifdef HAVE_GETUSERATTR
-               set_limits_from_userattr(pw->pw_name);
-#endif /* HAVE_GETUSERATTR */
+#ifdef HAVE_SETPCRED
+               setpcred(pw->pw_name);
+#endif /* HAVE_SETPCRED */
 #ifdef HAVE_LOGIN_CAP
+# ifdef __bsdi__
+               setpgid(0, 0);
+# endif
                if (setusercontext(lc, pw, pw->pw_uid,
                    (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) {
                        perror("unable to set user context");
@@ -1105,6 +1220,9 @@ do_setusercontext(struct passwd *pw)
 # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY)
                irix_setusercontext(pw);
 #  endif /* defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) */
+# ifdef _AIX
+               aix_usrinfo(pw);
+# endif /* _AIX */
                /* Permanently switch to the desired uid. */
                permanently_set_uid(pw);
 #endif
@@ -1167,9 +1285,6 @@ do_child(Session *s, const char *command)
                        do_motd();
 #else /* HAVE_OSF_SIA */
                do_nologin(pw);
-# ifdef _AIX
-               aix_usrinfo(pw, s->tty, s->ttyfd);
-# endif /* _AIX */
                do_setusercontext(pw);
 #endif /* HAVE_OSF_SIA */
        }
@@ -1343,12 +1458,12 @@ session_dump(void)
        int i;
        for (i = 0; i < MAX_SESSIONS; i++) {
                Session *s = &sessions[i];
-               debug("dump: used %d session %d %p channel %d pid %d",
+               debug("dump: used %d session %d %p channel %d pid %ld",
                    s->used,
                    s->self,
                    s,
                    s->chanid,
-                   s->pid);
+                   (long)s->pid);
        }
 }
 
@@ -1406,13 +1521,13 @@ static Session *
 session_by_pid(pid_t pid)
 {
        int i;
-       debug("session_by_pid: pid %d", pid);
+       debug("session_by_pid: pid %ld", (long)pid);
        for (i = 0; i < MAX_SESSIONS; i++) {
                Session *s = &sessions[i];
                if (s->used && s->pid == pid)
                        return s;
        }
-       error("session_by_pid: unknown pid %d", pid);
+       error("session_by_pid: unknown pid %ld", (long)pid);
        session_dump();
        return NULL;
 }
@@ -1702,8 +1817,8 @@ session_exit_message(Session *s, int status)
        if ((c = channel_lookup(s->chanid)) == NULL)
                fatal("session_exit_message: session %d: no channel %d",
                    s->self, s->chanid);
-       debug("session_exit_message: session %d channel %d pid %d",
-           s->self, s->chanid, s->pid);
+       debug("session_exit_message: session %d channel %d pid %ld",
+           s->self, s->chanid, (long)s->pid);
 
        if (WIFEXITED(status)) {
                channel_request_start(s->chanid, "exit-status", 0);
@@ -1742,7 +1857,7 @@ session_exit_message(Session *s, int status)
 void
 session_close(Session *s)
 {
-       debug("session_close: session %d pid %d", s->self, s->pid);
+       debug("session_close: session %d pid %ld", s->self, (long)s->pid);
        if (s->ttyfd != -1) {
                fatal_remove_cleanup(session_pty_cleanup, (void *)s);
                session_pty_cleanup(s);
@@ -1766,7 +1881,8 @@ session_close_by_pid(pid_t pid, int status)
 {
        Session *s = session_by_pid(pid);
        if (s == NULL) {
-               debug("session_close_by_pid: no session for pid %d", pid);
+               debug("session_close_by_pid: no session for pid %ld",
+                   (long)pid);
                return;
        }
        if (s->chanid != -1)
@@ -1786,7 +1902,8 @@ session_close_by_channel(int id, void *arg)
                debug("session_close_by_channel: no session for id %d", id);
                return;
        }
-       debug("session_close_by_channel: channel %d child %d", id, s->pid);
+       debug("session_close_by_channel: channel %d child %ld",
+           id, (long)s->pid);
        if (s->pid != 0) {
                debug("session_close_by_channel: channel %d: has child", id);
                /*
@@ -1877,9 +1994,9 @@ session_setup_x11fwd(Session *s)
                debug("X11 display already set.");
                return 0;
        }
-       s->display_number = x11_create_display_inet(options.x11_display_offset,
-           options.x11_use_localhost, s->single_connection);
-       if (s->display_number == -1) {
+       if (x11_create_display_inet(options.x11_display_offset,
+           options.x11_use_localhost, s->single_connection,
+           &s->display_number) == -1) {
                debug("x11_create_display_inet failed.");
                return 0;
        }
@@ -1893,9 +2010,9 @@ session_setup_x11fwd(Session *s)
         * different than the DISPLAY string for localhost displays.
         */
        if (options.x11_use_localhost) {
-               snprintf(display, sizeof display, "localhost:%d.%d",
+               snprintf(display, sizeof display, "localhost:%u.%u",
                    s->display_number, s->screen);
-               snprintf(auth_display, sizeof auth_display, "unix:%d.%d",
+               snprintf(auth_display, sizeof auth_display, "unix:%u.%u",
                    s->display_number, s->screen);
                s->display = xstrdup(display);
                s->auth_display = xstrdup(auth_display);
@@ -1911,10 +2028,10 @@ session_setup_x11fwd(Session *s)
                        return 0;
                }
                memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr));
-               snprintf(display, sizeof display, "%.50s:%d.%d", inet_ntoa(my_addr),
+               snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr),
                    s->display_number, s->screen);
 #else
-               snprintf(display, sizeof display, "%.400s:%d.%d", hostname,
+               snprintf(display, sizeof display, "%.400s:%u.%u", hostname,
                    s->display_number, s->screen);
 #endif
                s->display = xstrdup(display);
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