X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/a3b678a332263f4d552804fc459a10411672cdd2..4268576346a1178dd4baa884d215545e9bc3113e:/session.c diff --git a/session.c b/session.c index 325b1753..0a321be3 100644 --- a/session.c +++ b/session.c @@ -1,3 +1,4 @@ +/* $OpenBSD: session.c,v 1.207 2006/07/08 21:48:53 stevesk Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -33,7 +34,22 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.159 2003/07/22 13:35:22 markus Exp $"); + +#include +#ifdef HAVE_SYS_STAT_H +# include +#endif +#include +#include +#include + +#include +#ifdef HAVE_PATHS_H +#include +#endif +#include +#include +#include #include "ssh.h" #include "ssh1.h" @@ -42,7 +58,7 @@ RCSID("$OpenBSD: session.c,v 1.159 2003/07/22 13:35:22 markus Exp $"); #include "sshpty.h" #include "packet.h" #include "buffer.h" -#include "mpaux.h" +#include "match.h" #include "uidswap.h" #include "compat.h" #include "channels.h" @@ -56,13 +72,22 @@ RCSID("$OpenBSD: session.c,v 1.159 2003/07/22 13:35:22 markus Exp $"); #include "serverloop.h" #include "canohost.h" #include "session.h" +#include "kex.h" #include "monitor_wrap.h" +#if defined(KRB5) && defined(USE_AFS) +#include +#endif + +#ifdef GSSAPI +#include "ssh-gss.h" +#endif + /* func */ 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 *); @@ -102,6 +127,8 @@ 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; @@ -109,10 +136,8 @@ 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); @@ -140,7 +165,7 @@ 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) { @@ -156,9 +181,6 @@ 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) @@ -169,14 +191,14 @@ auth_input_request_forwarding(struct passwd * pw) 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) + 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) + if (listen(sock, SSH_LISTEN_BACKLOG) < 0) packet_disconnect("listen: %.100s", strerror(errno)); /* Allocate a channel for the authentication agent socket. */ @@ -188,22 +210,21 @@ 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", (char *)buffer_ptr(&loginmsg)); + buffer_clear(&loginmsg); + } +} void 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(); @@ -213,13 +234,7 @@ 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); } /* @@ -238,6 +253,10 @@ 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; @@ -257,11 +276,11 @@ 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; } @@ -328,30 +347,6 @@ do_authenticated1(Authctxt *authctxt) success = 1; break; -#ifdef KRB5 - case SSH_CMSG_HAVE_KERBEROS_TGT: - if (!options.kerberos_tgt_passing) { - verbose("Kerberos TGT passing disabled."); - } else { - char *kdata = packet_get_string(&dlen); - packet_check_eom(); - - /* XXX - 0x41, used for AFS */ - if (kdata[0] != 0x41) { - krb5_data tgt; - tgt.data = kdata; - tgt.length = dlen; - - if (auth_krb5_tgt(s->authctxt, &tgt)) - success = 1; - else - verbose("Kerberos v5 TGT refused for %.100s", s->authctxt->user); - } - xfree(kdata); - } - break; -#endif - case SSH_CMSG_EXEC_SHELL: case SSH_CMSG_EXEC_CMD: if (type == SSH_CMSG_EXEC_CMD) { @@ -415,18 +410,13 @@ do_exec_no_pty(Session *s, const char *command) session_proctitle(s); #if defined(USE_PAM) - if (options.use_pam) { - do_pam_session(s->pw->pw_name, NULL); + 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); @@ -502,7 +492,11 @@ do_exec_no_pty(Session *s, const char *command) close(perr[1]); if (compat20) { - session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); + if (s->is_subsystem) { + close(perr[0]); + perr[0] = -1; + } + session_set_fds(s, pin[1], pout[0], perr[0]); } else { /* Enter the interactive session. */ server_loop(pid, pin[1], pout[0], perr[0]); @@ -513,6 +507,13 @@ do_exec_no_pty(Session *s, const char *command) close(inout[0]); close(err[0]); + /* + * Clear loginmsg, since 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); + /* * Enter the interactive session. Note: server_loop must be able to * handle the case that fdin and fdout are the same. @@ -545,14 +546,15 @@ do_exec_pty(Session *s, const char *command) #if defined(USE_PAM) if (options.use_pam) { - do_pam_session(s->pw->pw_name, s->tty); - do_pam_setcred(1); + do_pam_set_tty(s->tty); + 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); @@ -646,9 +648,9 @@ do_pre_login(Session *s) fromlen = sizeof(from); if (packet_connection_is_on_socket()) { if (getpeername(packet_get_connection_in(), - (struct sockaddr *) & from, &fromlen) < 0) { + (struct sockaddr *)&from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } @@ -671,20 +673,37 @@ do_exec(Session *s, const char *command) debug("Forced command '%.900s'", command); } +#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 + if (s->ttyfd != -1) do_exec_pty(s, command); else 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; @@ -700,7 +719,7 @@ 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); } } @@ -716,39 +735,18 @@ 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 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); - -#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 */ + display_loginmsg(); do_motd(); } @@ -806,12 +804,23 @@ check_quietlogin(Session *s, const char *command) * Sets the value of the given variable in the environment. If the variable * already exists, its value is overriden. */ -static void +void child_set_env(char ***envp, u_int *envsizep, const char *name, const char *value) { - u_int i, namelen; char **env; + u_int envsize; + u_int i, namelen; + + /* + * If we're passed an uninitialized list, allocate a single null + * entry before continuing. + */ + if (*envp == NULL && *envsizep == 0) { + *envp = xmalloc(sizeof(char *)); + *envp[0] = NULL; + *envsizep = 1; + } /* * Find the slot where the value should be stored. If the variable @@ -828,12 +837,13 @@ child_set_env(char ***envp, u_int *envsizep, const char *name, xfree(env[i]); } 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 *)); + envsize = *envsizep; + if (i >= envsize - 1) { + if (envsize >= 1000) + fatal("child_set_env: too many env vars"); + envsize += 50; + env = (*envp) = xrealloc(env, envsize, sizeof(char *)); + *envsizep = envsize; } /* Need to set the NULL pointer at end of array beyond the new slot. */ env[i + 1] = NULL; @@ -889,7 +899,63 @@ read_environment_file(char ***env, u_int *envsize, fclose(f); } -void copy_environment(char **source, char ***env, u_int *envsize) +#ifdef HAVE_ETC_DEFAULT_LOGIN +/* + * Return named variable from specified environment, or NULL if not present. + */ +static char * +child_get_env(char **env, const char *name) +{ + int i; + size_t len; + + len = strlen(name); + for (i=0; env[i] != NULL; i++) + if (strncmp(name, env[i], len) == 0 && env[i][len] == '=') + return(env[i] + len + 1); + return NULL; +} + +/* + * Read /etc/default/login. + * We pick up the PATH (or SUPATH for root) and UMASK. + */ +static void +read_etc_default_login(char ***env, u_int *envsize, uid_t uid) +{ + char **tmpenv = NULL, *var; + u_int i, tmpenvsize = 0; + u_long mask; + + /* + * We don't want to copy the whole file to the child's environment, + * so we use a temporary environment and copy the variables we're + * interested in. + */ + read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); + + if (tmpenv == NULL) + return; + + if (uid == 0) + var = child_get_env(tmpenv, "SUPATH"); + else + 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((mode_t)mask); + + for (i = 0; tmpenv[i] != NULL; i++) + xfree(tmpenv[i]); + xfree(tmpenv); +} +#endif /* HAVE_ETC_DEFAULT_LOGIN */ + +void +copy_environment(char **source, char ***env, u_int *envsize) { char *var_name, *var_val; int i; @@ -907,7 +973,7 @@ 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); } } @@ -917,12 +983,12 @@ do_setup_env(Session *s, const char *shell) { char buf[256]; u_int i, envsize; - char **env, *laddr; + char **env, *laddr, *path = NULL; struct passwd *pw = s->pw; /* Initialize the environment. */ envsize = 100; - env = xmalloc(envsize * sizeof(char *)); + env = xcalloc(envsize, sizeof(char *)); env[0] = NULL; #ifdef HAVE_CYGWIN @@ -930,11 +996,28 @@ 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 + /* Allow any GSSAPI methods that we've used to alter + * the childs environment as they see fit + */ + ssh_gssapi_do_child(&env, &envsize); #endif if (!options.use_login) { /* Set basic environment. */ + for (i = 0; i < s->num_env; i++) + child_set_env(&env, &envsize, s->env[i].name, + s->env[i].val); + child_set_env(&env, &envsize, "USER", pw->pw_name); child_set_env(&env, &envsize, "LOGNAME", pw->pw_name); #ifdef _AIX @@ -954,12 +1037,15 @@ do_setup_env(Session *s, const char *shell) * needed for loading shared libraries. So the path better * remains intact here. */ -# ifdef SUPERUSER_PATH - child_set_env(&env, &envsize, "PATH", - s->pw->pw_uid == 0 ? SUPERUSER_PATH : _PATH_STDPATH); -# else - child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); -# endif /* SUPERUSER_PATH */ +# ifdef HAVE_ETC_DEFAULT_LOGIN + read_etc_default_login(&env, &envsize, pw->pw_uid); + path = child_get_env(env, "PATH"); +# endif /* HAVE_ETC_DEFAULT_LOGIN */ + if (path == NULL || *path == '\0') { + child_set_env(&env, &envsize, "PATH", + s->pw->pw_uid == 0 ? + SUPERUSER_PATH : _PATH_STDPATH); + } # endif /* HAVE_CYGWIN */ #endif /* HAVE_LOGIN_CAP */ @@ -1017,21 +1103,31 @@ 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 #ifdef KRB5 - if (s->authctxt->krb5_ticket_file) + if (s->authctxt->krb5_ccname) child_set_env(&env, &envsize, "KRB5CCNAME", - s->authctxt->krb5_ticket_file); + s->authctxt->krb5_ccname); #endif #ifdef USE_PAM /* @@ -1039,8 +1135,13 @@ 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); } @@ -1113,7 +1214,7 @@ 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, @@ -1179,6 +1280,19 @@ 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(); + do_pam_setcred(0); + } +# endif /* USE_PAM */ if (setusercontext(lc, pw, pw->pw_uid, (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { perror("unable to set user context"); @@ -1203,14 +1317,23 @@ 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. + * PAM credentials may take the form of supplementary groups. * These will have been wiped by the above initgroups() call. * Reestablish them here. */ - if (options.use_pam) + if (options.use_pam) { + do_pam_session(); do_pam_setcred(0); + } # endif /* USE_PAM */ # if defined(WITH_IRIX_PROJECT) || defined(WITH_IRIX_JOBS) || defined(WITH_IRIX_ARRAY) irix_setusercontext(pw); @@ -1218,6 +1341,11 @@ 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 @@ -1228,6 +1356,32 @@ do_setusercontext(struct passwd *pw) #endif if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); + +#ifdef WITH_SELINUX + ssh_selinux_setup_exec_context(pw->pw_name); +#endif +} + +static void +do_pwchange(Session *s) +{ + fflush(NULL); + fprintf(stderr, "WARNING: Your password has expired.\n"); + if (s->ttyfd != -1) { + 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, + "Password change required but no TTY available.\n"); + } + exit(1); } static void @@ -1251,6 +1405,40 @@ 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 @@ -1264,11 +1452,18 @@ do_child(Session *s, const char *command) char *argv[10]; const char *shell, *shell0, *hostname = NULL; struct passwd *pw = s->pw; - u_int i; /* 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; @@ -1287,11 +1482,28 @@ 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. @@ -1319,41 +1531,41 @@ 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()); - } - /* - * Close all descriptors related to channels. They will still remain - * open in the parent. - */ - /* XXX better use close-on-exec? -markus */ - channel_close_all(); + child_close_fds(); /* - * Close any extra file descriptors. Note that there may still be - * descriptors left by system functions. They will be closed later. + * Must take new environment into use so that .ssh/rc, + * /etc/ssh/sshrc and xauth are run in the proper environment. */ - endpwent(); + environ = env; +#if defined(KRB5) && defined(USE_AFS) /* - * 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. + * 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. */ - for (i = 3; i < 64; i++) - close(i); - /* - * Must take new environment into use so that .ssh/rc, - * /etc/ssh/sshrc and xauth are run in the proper environment. - */ - environ = env; + if (options.kerberos_get_afs_token && k_hasafs() && + (s->authctxt->krb5_ctx != NULL)) { + char cell[64]; + + debug("Getting AFS token"); - /* Change current directory to the user\'s home directory. */ + 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) { fprintf(stderr, "Could not chdir to home directory %s: %s\n", pw->pw_dir, strerror(errno)); @@ -1441,6 +1653,7 @@ session_new(void) s->ttyfd = -1; s->used = 1; s->self = i; + s->x11_chanids = NULL; debug("session_new: session %d", i); return s; } @@ -1474,7 +1687,7 @@ 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; @@ -1513,6 +1726,29 @@ 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) { @@ -1554,12 +1790,6 @@ 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); @@ -1596,11 +1826,6 @@ 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); @@ -1618,17 +1843,18 @@ session_subsystem_req(Session *s) struct stat st; u_int len; int success = 0; - char *cmd, *subsys = packet_get_string(&len); - int i; + char *prog, *cmd, *subsys = packet_get_string(&len); + u_int i; packet_check_eom(); logit("subsystem request for %.100s", subsys); for (i = 0; i < options.num_subsystems; i++) { if (strcmp(subsys, options.subsystem_name[i]) == 0) { - cmd = options.subsystem_command[i]; - if (stat(cmd, &st) < 0) { - error("subsystem: cannot stat %s: %s", cmd, + prog = options.subsystem_command[i]; + cmd = options.subsystem_args[i]; + if (stat(prog, &st) < 0) { + error("subsystem: cannot stat %s: %s", prog, strerror(errno)); break; } @@ -1653,6 +1879,11 @@ 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); @@ -1691,25 +1922,49 @@ session_exec_req(Session *s) static int session_break_req(Session *s) { - u_int break_length; - break_length = packet_get_int(); + packet_get_int(); /* ignored */ packet_check_eom(); -#if defined(TIOCSBRK) && defined(TIOCCBRK) - if (s->ttyfd == -1) + if (s->ttyfd == -1 || + tcsendbreak(s->ttyfd, 0) < 0) return 0; - /* we will sleep from 500ms to 3000ms */ - break_length = MIN(break_length, 3000); - break_length = MAX(break_length, 500); - ioctl(s->ttyfd, TIOCSBRK, NULL); - /* should we care about EINTR? */ - usleep(break_length * 1000); - ioctl(s->ttyfd, TIOCCBRK, NULL); return 1; -#else - return 0; -#endif +} + +static int +session_env_req(Session *s) +{ + char *name, *val; + u_int name_len, val_len, i; + + name = packet_get_string(&name_len); + val = packet_get_string(&val_len); + packet_check_eom(); + + /* Don't set too many environment variables */ + if (s->num_env > 128) { + debug2("Ignoring env request %s: too many env vars", name); + goto fail; + } + + for (i = 0; i < options.num_accept_env; i++) { + if (match_pattern(name, options.accept_env[i])) { + debug2("Setting env %d: %s=%s", s->num_env, name, val); + s->env = xrealloc(s->env, s->num_env + 1, + sizeof(*s->env)); + s->env[s->num_env].name = name; + s->env[s->num_env].val = val; + s->num_env++; + return (1); + } + } + debug2("Ignoring env request %s: disallowed name", name); + + fail: + xfree(name); + xfree(val); + return (0); } static int @@ -1759,13 +2014,16 @@ session_input_channel_req(Channel *c, const char *rtype) success = session_auth_agent_req(s); } else if (strcmp(rtype, "subsystem") == 0) { success = session_subsystem_req(s); - } else if (strcmp(rtype, "break") == 0) { - success = session_break_req(s); + } else if (strcmp(rtype, "env") == 0) { + success = session_env_req(s); } } if (strcmp(rtype, "window-change") == 0) { success = session_window_change_req(s); + } else if (strcmp(rtype, "break") == 0) { + success = session_break_req(s); } + return success; } @@ -1792,10 +2050,8 @@ 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; @@ -1826,9 +2082,9 @@ 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 * @@ -1852,6 +2108,62 @@ 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) { @@ -1885,7 +2197,14 @@ 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. @@ -1894,21 +2213,22 @@ 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) { + u_int i; + 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) xfree(s->display); + if (s->x11_chanids) + xfree(s->x11_chanids); if (s->auth_display) xfree(s->auth_display); if (s->auth_data) @@ -1916,6 +2236,12 @@ session_close(Session *s) if (s->auth_proto) xfree(s->auth_proto); s->used = 0; + for (i = 0; i < s->num_env; i++) { + xfree(s->env[i].name); + xfree(s->env[i].val); + } + if (s->env != NULL) + xfree(s->env); session_proctitle(s); } @@ -1930,7 +2256,9 @@ 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; } /* @@ -1941,6 +2269,8 @@ 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; @@ -1953,14 +2283,21 @@ 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 */ 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); } @@ -1991,13 +2328,13 @@ 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); @@ -2023,6 +2360,7 @@ 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."); @@ -2048,10 +2386,14 @@ 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) @@ -2098,3 +2440,50 @@ do_authenticated2(Authctxt *authctxt) { server_loop2(authctxt); } + +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); +}