diff options
Diffstat (limited to 'crypto/openssh/session.c')
| -rw-r--r-- | crypto/openssh/session.c | 291 |
1 files changed, 191 insertions, 100 deletions
diff --git a/crypto/openssh/session.c b/crypto/openssh/session.c index f90bf06..3913214 100644 --- a/crypto/openssh/session.c +++ b/crypto/openssh/session.c @@ -33,7 +33,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.164 2003/09/18 08:49:45 markus Exp $"); +RCSID("$OpenBSD: session.c,v 1.172 2004/01/30 09:48:57 markus Exp $"); RCSID("$FreeBSD$"); #include "ssh.h" @@ -59,6 +59,10 @@ RCSID("$FreeBSD$"); #include "session.h" #include "monitor_wrap.h" +#if defined(KRB5) && defined(USE_AFS) +#include <kafs.h> +#endif + #ifdef GSSAPI #include "ssh-gss.h" #endif @@ -67,7 +71,7 @@ RCSID("$FreeBSD$"); Session *session_new(void); void session_set_fds(Session *, int, int, int); -void session_pty_cleanup(void *); +void session_pty_cleanup(Session *); void session_proctitle(Session *); int session_setup_x11fwd(Session *); void do_exec_pty(Session *, const char *); @@ -107,6 +111,8 @@ Session sessions[MAX_SESSIONS]; login_cap_t *lc; #endif +static int is_child = 0; + /* Name and directory of socket for authentication agent forwarding. */ static char *auth_sock_name = NULL; static char *auth_sock_dir = NULL; @@ -114,10 +120,8 @@ static char *auth_sock_dir = NULL; /* removes the agent forwarding socket */ static void -auth_sock_cleanup_proc(void *_pw) +auth_sock_cleanup_proc(struct passwd *pw) { - struct passwd *pw = _pw; - if (auth_sock_name != NULL) { temporarily_use_uid(pw); unlink(auth_sock_name); @@ -145,7 +149,7 @@ auth_input_request_forwarding(struct passwd * 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); + strlcpy(auth_sock_dir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN); /* Create private directory for socket */ if (mkdtemp(auth_sock_dir) == NULL) { @@ -161,9 +165,6 @@ auth_input_request_forwarding(struct passwd * pw) 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) @@ -181,7 +182,7 @@ auth_input_request_forwarding(struct passwd * pw) restore_uid(); /* Start listening on the socket. */ - if (listen(sock, 5) < 0) + if (listen(sock, SSH_LISTEN_BACKLOG) < 0) packet_disconnect("listen: %.100s", strerror(errno)); /* Allocate a channel for the authentication agent socket. */ @@ -193,6 +194,15 @@ auth_input_request_forwarding(struct passwd * pw) return 1; } +static void +display_loginmsg(void) +{ + if (buffer_len(&loginmsg) > 0) { + buffer_append(&loginmsg, "\0", 1); + printf("%s\n", (char *)buffer_ptr(&loginmsg)); + buffer_clear(&loginmsg); + } +} void do_authenticated(Authctxt *authctxt) @@ -208,7 +218,6 @@ do_authenticated(Authctxt *authctxt) close(startup_pipe); startup_pipe = -1; } - /* setup the channel layer */ if (!no_port_forwarding_flag && options.allow_tcp_forwarding) channel_permit_all_opens(); @@ -218,13 +227,7 @@ do_authenticated(Authctxt *authctxt) else do_authenticated1(authctxt); - /* remove agent socket */ - if (auth_sock_name != NULL) - auth_sock_cleanup_proc(authctxt->pw); -#ifdef KRB5 - if (options.kerberos_ticket_cleanup) - krb5_cleanup_proc(authctxt); -#endif + do_cleanup(authctxt); } /* @@ -396,17 +399,13 @@ do_exec_no_pty(Session *s, const char *command) session_proctitle(s); #if defined(USE_PAM) - if (options.use_pam) { + if (options.use_pam && !use_privsep) do_pam_setcred(1); - if (is_pam_password_change_required()) - packet_disconnect("Password change required but no " - "TTY available"); - } #endif /* USE_PAM */ /* Fork the child. */ if ((pid = fork()) == 0) { - fatal_remove_all_cleanups(); + is_child = 1; /* Child. Reinitialize the log since the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); @@ -526,13 +525,14 @@ do_exec_pty(Session *s, const char *command) #if defined(USE_PAM) if (options.use_pam) { do_pam_set_tty(s->tty); - do_pam_setcred(1); + if (!use_privsep) + do_pam_setcred(1); } #endif /* Fork the child. */ if ((pid = fork()) == 0) { - fatal_remove_all_cleanups(); + is_child = 1; /* Child. Reinitialize the log because the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); @@ -628,7 +628,7 @@ do_pre_login(Session *s) if (getpeername(packet_get_connection_in(), (struct sockaddr *) & from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } @@ -688,7 +688,7 @@ do_login(Session *s, const char *command) if (getpeername(packet_get_connection_in(), (struct sockaddr *) & from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } @@ -704,9 +704,10 @@ do_login(Session *s, const char *command) * If password change is needed, do it now. * This needs to occur before the ~/.hushlogin check. */ - if (options.use_pam && is_pam_password_change_required()) { - print_pam_messages(); + if (options.use_pam && !use_privsep && s->authctxt->force_pwchange) { + display_loginmsg(); do_pam_chauthtok(); + s->authctxt->force_pwchange = 0; /* XXX - signal [net] parent to enable forwardings */ } #endif @@ -714,17 +715,7 @@ do_login(Session *s, const char *command) if (check_quietlogin(s, command)) return; -#ifdef USE_PAM - if (options.use_pam && !is_pam_password_change_required()) - print_pam_messages(); -#endif /* USE_PAM */ - - /* display post-login message */ - if (buffer_len(&loginmsg) > 0) { - buffer_append(&loginmsg, "\0", 1); - printf("%s\n", (char *)buffer_ptr(&loginmsg)); - } - buffer_free(&loginmsg); + display_loginmsg(); #ifndef NO_SSH_LASTLOG if (options.print_lastlog && s->last_login_time != 0) { @@ -934,7 +925,7 @@ read_etc_default_login(char ***env, u_int *envsize, uid_t uid) { char **tmpenv = NULL, *var; u_int i, tmpenvsize = 0; - mode_t mask; + u_long mask; /* * We don't want to copy the whole file to the child's environment, @@ -952,11 +943,11 @@ read_etc_default_login(char ***env, u_int *envsize, uid_t uid) var = child_get_env(tmpenv, "PATH"); if (var != NULL) child_set_env(env, envsize, "PATH", var); - + if ((var = child_get_env(tmpenv, "UMASK")) != NULL) if (sscanf(var, "%5lo", &mask) == 1) - umask(mask); - + umask((mode_t)mask); + for (i = 0; tmpenv[i] != NULL; i++) xfree(tmpenv[i]); xfree(tmpenv); @@ -981,7 +972,7 @@ void copy_environment(char **source, char ***env, u_int *envsize) debug3("Copy environment: %s=%s", var_name, var_val); child_set_env(env, envsize, var_name, var_val); - + xfree(var_name); } } @@ -1015,7 +1006,7 @@ do_setup_env(Session *s, const char *shell) child_set_env(&env, &envsize, "TZ", getenv("TZ")); #ifdef GSSAPI - /* Allow any GSSAPI methods that we've used to alter + /* Allow any GSSAPI methods that we've used to alter * the childs environment as they see fit */ ssh_gssapi_do_child(&env, &envsize); @@ -1058,7 +1049,7 @@ do_setup_env(Session *s, const char *shell) path = child_get_env(env, "PATH"); # endif /* HAVE_ETC_DEFAULT_LOGIN */ if (path == NULL || *path == '\0') { - child_set_env(&env, &envsize, "PATH", + child_set_env(&env, &envsize, "PATH", s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); } @@ -1135,8 +1126,13 @@ do_setup_env(Session *s, const char *shell) * been set by PAM. */ if (options.use_pam) { - char **p = fetch_pam_environment(); + char **p; + p = fetch_pam_child_environment(); + copy_environment(p, &env, &envsize); + free_pam_environment(p); + + p = fetch_pam_environment(); copy_environment(p, &env, &envsize); free_pam_environment(p); } @@ -1209,7 +1205,7 @@ do_rc_files(Session *s, const char *shell) if (debug_flag) { fprintf(stderr, "Running %.500s remove %.100s\n", - options.xauth_location, s->auth_display); + options.xauth_location, s->auth_display); fprintf(stderr, "%.500s add %.100s %.100s %.100s\n", options.xauth_location, s->auth_display, @@ -1275,6 +1271,12 @@ do_setusercontext(struct passwd *pw) # ifdef __bsdi__ setpgid(0, 0); # endif +# ifdef USE_PAM + if (options.use_pam) { + do_pam_session(); + do_pam_setcred(0); + } +# endif /* USE_PAM */ if (setusercontext(lc, pw, pw->pw_uid, (LOGIN_SETALL & ~(LOGIN_SETENV|LOGIN_SETPATH))) < 0) { perror("unable to set user context"); @@ -1301,7 +1303,7 @@ do_setusercontext(struct passwd *pw) endgrent(); # ifdef USE_PAM /* - * PAM credentials may take the form of supplementary groups. + * PAM credentials may take the form of supplementary groups. * These will have been wiped by the above initgroups() call. * Reestablish them here. */ @@ -1329,6 +1331,22 @@ do_setusercontext(struct passwd *pw) } static void +do_pwchange(Session *s) +{ + fprintf(stderr, "WARNING: Your password has expired.\n"); + if (s->ttyfd != -1) { + fprintf(stderr, + "You must change your password now and login again!\n"); + execl(_PATH_PASSWD_PROG, "passwd", (char *)NULL); + perror("passwd"); + } else { + fprintf(stderr, + "Password change required but no TTY available.\n"); + } + exit(1); +} + +static void launch_login(struct passwd *pw, const char *hostname) { /* Launch login(1). */ @@ -1349,6 +1367,40 @@ launch_login(struct passwd *pw, const char *hostname) exit(1); } +static void +child_close_fds(void) +{ + int i; + + if (packet_get_connection_in() == packet_get_connection_out()) + close(packet_get_connection_in()); + else { + close(packet_get_connection_in()); + close(packet_get_connection_out()); + } + /* + * Close all descriptors related to channels. They will still remain + * open in the parent. + */ + /* XXX better use close-on-exec? -markus */ + channel_close_all(); + + /* + * Close any extra file descriptors. Note that there may still be + * descriptors left by system functions. They will be closed later. + */ + endpwent(); + + /* + * 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. + */ + for (i = 3; i < 64; i++) + close(i); +} + /* * Performs common processing for the child, such as setting up the * environment, closing extra file descriptors, setting the user and group @@ -1362,7 +1414,6 @@ do_child(Session *s, const char *command) char *argv[10]; const char *shell, *shell0, *hostname = NULL; struct passwd *pw = s->pw; - u_int i; #ifdef HAVE_LOGIN_CAP int lc_requirehome; #endif @@ -1370,6 +1421,14 @@ do_child(Session *s, const char *command) /* remove hostkey from the child's memory */ destroy_sensitive_data(); + /* Force a password change */ + if (s->authctxt->force_pwchange) { + do_setusercontext(pw); + child_close_fds(); + do_pwchange(s); + exit(1); + } + /* login(1) is only called if we execute the login shell */ if (options.use_login && command != NULL) options.use_login = 0; @@ -1420,43 +1479,43 @@ do_child(Session *s, const char *command) * closed before building the environment, as we call * get_remote_ipaddr there. */ - if (packet_get_connection_in() == packet_get_connection_out()) - close(packet_get_connection_in()); - else { - close(packet_get_connection_in()); - close(packet_get_connection_out()); - } + child_close_fds(); + /* - * Close all descriptors related to channels. They will still remain - * open in the parent. + * Must take new environment into use so that .ssh/rc, + * /etc/ssh/sshrc and xauth are run in the proper environment. */ - /* XXX better use close-on-exec? -markus */ - channel_close_all(); + environ = env; #ifdef HAVE_LOGIN_CAP lc_requirehome = login_getcapbool(lc, "requirehome", 0); login_close(lc); #endif +#if defined(KRB5) && defined(USE_AFS) /* - * Close any extra file descriptors. Note that there may still be - * descriptors left by system functions. They will be closed later. + * At this point, we check to see if AFS is active and if we have + * a valid Kerberos 5 TGT. If so, it seems like a good idea to see + * if we can (and need to) extend the ticket into an AFS token. If + * we don't do this, we run into potential problems if the user's + * home directory is in AFS and it's not world-readable. */ - endpwent(); - /* - * 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. - */ - for (i = 3; i < 64; i++) - close(i); + if (options.kerberos_get_afs_token && k_hasafs() && + (s->authctxt->krb5_ctx != NULL)) { + char cell[64]; - /* - * Must take new environment into use so that .ssh/rc, - * /etc/ssh/sshrc and xauth are run in the proper environment. - */ - environ = env; + debug("Getting AFS token"); + + k_setpag(); + + if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) + krb5_afslog(s->authctxt->krb5_ctx, + s->authctxt->krb5_fwd_ccache, cell, NULL); + + krb5_afslog_home(s->authctxt->krb5_ctx, + s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); + } +#endif /* Change current directory to the user\'s home directory. */ if (chdir(pw->pw_dir) < 0) { @@ -1579,7 +1638,7 @@ session_open(Authctxt *authctxt, int chanid) } s->authctxt = authctxt; s->pw = authctxt->pw; - if (s->pw == NULL) + if (s->pw == NULL || !authctxt->valid) fatal("no user for session %d", s->self); debug("session_open: session %d: link with channel %d", s->self, chanid); s->chanid = chanid; @@ -1701,11 +1760,6 @@ session_pty_req(Session *s) n_bytes = packet_remaining(); tty_parse_modes(s->ttyfd, &n_bytes); - /* - * Add a cleanup function to clear the utmp entry and record logout - * time in case we call fatal() (e.g., the connection gets closed). - */ - fatal_add_cleanup(session_pty_cleanup, (void *)s); if (!use_privsep) pty_setowner(s->pw, s->tty); @@ -1887,10 +1941,8 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr) * (e.g., due to a dropped connection). */ void -session_pty_cleanup2(void *session) +session_pty_cleanup2(Session *s) { - Session *s = session; - if (s == NULL) { error("session_pty_cleanup: no session"); return; @@ -1921,9 +1973,9 @@ session_pty_cleanup2(void *session) } void -session_pty_cleanup(void *session) +session_pty_cleanup(Session *s) { - PRIVSEP(session_pty_cleanup2(session)); + PRIVSEP(session_pty_cleanup2(s)); } static char * @@ -1996,10 +2048,8 @@ void session_close(Session *s) { debug("session_close: session %d pid %ld", s->self, (long)s->pid); - if (s->ttyfd != -1) { - fatal_remove_cleanup(session_pty_cleanup, (void *)s); + if (s->ttyfd != -1) session_pty_cleanup(s); - } if (s->term) xfree(s->term); if (s->display) @@ -2048,10 +2098,8 @@ session_close_by_channel(int id, void *arg) * delay detach of session, but release pty, since * the fd's to the child are already closed */ - if (s->ttyfd != -1) { - fatal_remove_cleanup(session_pty_cleanup, (void *)s); + if (s->ttyfd != -1) session_pty_cleanup(s); - } return; } /* detach by removing callback */ @@ -2086,13 +2134,13 @@ session_tty_list(void) for (i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (s->used && s->ttyfd != -1) { - + if (strncmp(s->tty, "/dev/", 5) != 0) { cp = strrchr(s->tty, '/'); cp = (cp == NULL) ? s->tty : cp + 1; } else cp = s->tty + 5; - + if (buf[0] != '\0') strlcat(buf, ",", sizeof buf); strlcat(buf, cp, sizeof buf); @@ -2192,8 +2240,51 @@ static void do_authenticated2(Authctxt *authctxt) { server_loop2(authctxt); -#if defined(GSSAPI) - if (options.gss_cleanup_creds) - ssh_gssapi_cleanup_creds(NULL); +} + +void +do_cleanup(Authctxt *authctxt) +{ + static int called = 0; + + debug("do_cleanup"); + + /* no cleanup if we're in the child for login shell */ + if (is_child) + return; + + /* avoid double cleanup */ + if (called) + return; + called = 1; + + if (authctxt == NULL) + return; +#ifdef KRB5 + if (options.kerberos_ticket_cleanup && + authctxt->krb5_ctx) + krb5_cleanup_proc(authctxt); #endif + +#ifdef GSSAPI + if (compat20 && options.gss_cleanup_creds) + ssh_gssapi_cleanup_creds(); +#endif + +#ifdef USE_PAM + if (options.use_pam) { + sshpam_cleanup(); + sshpam_thread_cleanup(); + } +#endif + + /* remove agent socket */ + auth_sock_cleanup_proc(authctxt->pw); + + /* + * Cleanup ptys/utmp only if privsep is disabled, + * or if running in monitor. + */ + if (!use_privsep || mm_is_monitor()) + session_destroy_all(session_pty_cleanup2); } |
