X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/ef51930f93f523426b6c383a1802061fbede93be..be2ca0c95a7bca195f3c7626365f4994af30d34b:/session.c diff --git a/session.c b/session.c index 9074525a..99b84394 100644 --- a/session.c +++ b/session.c @@ -33,7 +33,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.150 2002/09/16 19:55:33 stevesk Exp $"); +RCSID("$OpenBSD: session.c,v 1.179 2004/07/17 05:31:41 dtucker Exp $"); #include "ssh.h" #include "ssh1.h" @@ -42,7 +42,7 @@ RCSID("$OpenBSD: session.c,v 1.150 2002/09/16 19:55:33 stevesk Exp $"); #include "sshpty.h" #include "packet.h" #include "buffer.h" -#include "mpaux.h" +#include "match.h" #include "uidswap.h" #include "compat.h" #include "channels.h" @@ -58,17 +58,19 @@ RCSID("$OpenBSD: session.c,v 1.150 2002/09/16 19:55:33 stevesk Exp $"); #include "session.h" #include "monitor_wrap.h" -#ifdef HAVE_CYGWIN -#include -#include -#define is_winnt (GetVersion() < 0x80000000) +#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 *); @@ -95,6 +97,7 @@ extern int debug_flag; extern u_int utmp_len; extern int startup_pipe; extern void destroy_sensitive_data(void); +extern Buffer loginmsg; /* original command from peer. */ const char *original_command = NULL; @@ -103,14 +106,12 @@ const char *original_command = NULL; #define MAX_SESSIONS 10 Session sessions[MAX_SESSIONS]; -#ifdef WITH_AIXAUTHENTICATE -char *aixloginmsg; -#endif /* WITH_AIXAUTHENTICATE */ - #ifdef HAVE_LOGIN_CAP 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; @@ -118,10 +119,8 @@ 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); @@ -149,7 +148,7 @@ 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) { @@ -165,9 +164,6 @@ 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) @@ -185,22 +181,33 @@ 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. */ 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); + 0, "auth socket", 1); strlcpy(nc->path, auth_sock_name, sizeof(nc->path)); 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. @@ -210,7 +217,6 @@ 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(); @@ -220,17 +226,7 @@ do_authenticated(Authctxt *authctxt) else do_authenticated1(authctxt); - /* remove agent socket */ - if (auth_sock_name != NULL) - auth_sock_cleanup_proc(authctxt->pw); -#ifdef KRB4 - if (options.kerberos_ticket_cleanup) - krb4_cleanup_proc(authctxt); -#endif -#ifdef KRB5 - if (options.kerberos_ticket_cleanup) - krb5_cleanup_proc(authctxt); -#endif + do_cleanup(authctxt); } /* @@ -339,58 +335,6 @@ do_authenticated1(Authctxt *authctxt) success = 1; break; -#if defined(AFS) || defined(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, see creds_to_radix version */ - if (kdata[0] != 0x41) { -#ifdef KRB5 - 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); -#endif /* KRB5 */ - } else { -#ifdef AFS - if (auth_krb4_tgt(s->authctxt, kdata)) - success = 1; - else - verbose("Kerberos v4 TGT refused for %.100s", s->authctxt->user); -#endif /* AFS */ - } - xfree(kdata); - } - break; -#endif /* AFS || KRB5 */ - -#ifdef AFS - case SSH_CMSG_HAVE_AFS_TOKEN: - if (!options.afs_token_passing || !k_hasafs()) { - verbose("AFS token passing disabled."); - } else { - /* Accept AFS token. */ - char *token = packet_get_string(&dlen); - packet_check_eom(); - - if (auth_afs_token(s->authctxt, token)) - success = 1; - else - verbose("AFS token refused for %.100s", - s->authctxt->user); - xfree(token); - } - break; -#endif /* AFS */ - case SSH_CMSG_EXEC_SHELL: case SSH_CMSG_EXEC_CMD: if (type == SSH_CMSG_EXEC_CMD) { @@ -410,7 +354,7 @@ do_authenticated1(Authctxt *authctxt) * Any unknown messages in this phase are ignored, * and a failure message is returned. */ - log("Unknown packet type received after authentication: %d", type); + logit("Unknown packet type received after authentication: %d", type); } packet_start(success ? SSH_SMSG_SUCCESS : SSH_SMSG_FAILURE); packet_send(); @@ -454,16 +398,13 @@ do_exec_no_pty(Session *s, const char *command) session_proctitle(s); #if defined(USE_PAM) - do_pam_session(s->pw->pw_name, NULL); - do_pam_setcred(1); - if (is_pam_password_change_required()) - packet_disconnect("Password change required but no " - "TTY available"); + if (options.use_pam && !use_privsep) + do_pam_setcred(1); #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); @@ -539,7 +480,11 @@ 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]); @@ -550,6 +495,13 @@ 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. @@ -581,13 +533,16 @@ do_exec_pty(Session *s, const char *command) ttyfd = s->ttyfd; #if defined(USE_PAM) - do_pam_session(s->pw->pw_name, s->tty); - do_pam_setcred(1); + if (options.use_pam) { + 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); @@ -683,13 +638,13 @@ 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); } } record_utmp_only(pid, s->tty, s->pw->pw_name, - get_remote_name_or_ip(utmp_len, options.verify_reverse_mapping), - (struct sockaddr *)&from); + get_remote_name_or_ip(utmp_len, options.use_dns), + (struct sockaddr *)&from, fromlen); } #endif @@ -706,20 +661,33 @@ 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(); + } +#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; @@ -730,12 +698,12 @@ do_login(Session *s, const char *command) * the address be 0.0.0.0. */ memset(&from, 0, sizeof(from)); + fromlen = sizeof(from); if (packet_connection_is_on_socket()) { - fromlen = sizeof(from); if (getpeername(packet_get_connection_in(), (struct sockaddr *) & from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } @@ -743,7 +711,7 @@ do_login(Session *s, const char *command) if (!use_privsep) record_login(pid, s->tty, pw->pw_name, pw->pw_uid, get_remote_name_or_ip(utmp_len, - options.verify_reverse_mapping), + options.use_dns), (struct sockaddr *)&from, fromlen); #ifdef USE_PAM @@ -751,36 +719,18 @@ do_login(Session *s, const char *command) * If password change is needed, do it now. * This needs to occur before the ~/.hushlogin check. */ - if (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 (!is_pam_password_change_required()) - print_pam_messages(); -#endif /* USE_PAM */ -#ifdef WITH_AIXAUTHENTICATE - if (aixloginmsg && *aixloginmsg) - printf("%s\n", aixloginmsg); -#endif /* WITH_AIXAUTHENTICATE */ - -#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(); } @@ -838,12 +788,23 @@ 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 @@ -860,12 +821,13 @@ 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; @@ -921,6 +883,61 @@ read_environment_file(char ***env, u_int *envsize, fclose(f); } +#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; @@ -939,7 +956,7 @@ 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); } } @@ -949,7 +966,7 @@ do_setup_env(Session *s, const char *shell) { char buf[256]; u_int i, envsize; - char **env; + char **env, *laddr, *path = NULL; struct passwd *pw = s->pw; /* Initialize the environment. */ @@ -965,10 +982,24 @@ do_setup_env(Session *s, const char *shell) copy_environment(environ, &env, &envsize); #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 + child_set_env(&env, &envsize, "LOGIN", pw->pw_name); +#endif child_set_env(&env, &envsize, "HOME", pw->pw_dir); #ifdef HAVE_LOGIN_CAP if (setusercontext(lc, pw, pw->pw_uid, LOGIN_SETPATH) < 0) @@ -983,12 +1014,15 @@ 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 */ @@ -1025,9 +1059,10 @@ do_setup_env(Session *s, const char *shell) get_remote_ipaddr(), get_remote_port(), get_local_port()); child_set_env(&env, &envsize, "SSH_CLIENT", buf); + laddr = get_local_ipaddr(packet_get_connection_in()); snprintf(buf, sizeof buf, "%.50s %d %.50s %d", - get_remote_ipaddr(), get_remote_port(), - get_local_ipaddr(packet_get_connection_in()), get_local_port()); + get_remote_ipaddr(), get_remote_port(), laddr, get_local_port()); + xfree(laddr); child_set_env(&env, &envsize, "SSH_CONNECTION", buf); if (s->ttyfd != -1) @@ -1056,24 +1091,23 @@ do_setup_env(Session *s, const char *shell) read_environment_file(&env, &envsize, "/etc/environment"); } #endif -#ifdef KRB4 - if (s->authctxt->krb4_ticket_file) - child_set_env(&env, &envsize, "KRBTKFILE", - s->authctxt->krb4_ticket_file); -#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 /* * Pull in any environment variables that may have * been set by PAM. */ - { + if (options.use_pam) { 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); @@ -1146,8 +1180,10 @@ do_rc_files(Session *s, const char *shell) /* Add authority data to .Xauthority if appropriate. */ if (debug_flag) { fprintf(stderr, - "Running %.500s add " - "%.100s %.100s %.100s\n", + "Running %.500s remove %.100s\n", + options.xauth_location, s->auth_display); + fprintf(stderr, + "%.500s add %.100s %.100s %.100s\n", options.xauth_location, s->auth_display, s->auth_proto, s->auth_data); } @@ -1155,6 +1191,8 @@ do_rc_files(Session *s, const char *shell) options.xauth_location); f = popen(cmd, "w"); if (f) { + fprintf(f, "remove %s\n", + s->auth_display); fprintf(f, "add %s %s %s\n", s->auth_display, s->auth_proto, s->auth_data); @@ -1182,11 +1220,12 @@ do_nologin(struct passwd *pw) #endif if (f) { /* /etc/nologin exists. Print its contents and exit. */ - log("User %.100s not allowed because %s exists", + logit("User %.100s not allowed because %s exists", pw->pw_name, _PATH_NOLOGIN); while (fgets(buf, sizeof(buf), f)) fputs(buf, stderr); fclose(f); + fflush(NULL); exit(254); } } @@ -1195,18 +1234,25 @@ do_nologin(struct passwd *pw) void do_setusercontext(struct passwd *pw) { -#ifdef HAVE_CYGWIN - if (is_winnt) { -#else /* HAVE_CYGWIN */ - if (getuid() == 0 || geteuid() == 0) { +#ifndef HAVE_CYGWIN + if (getuid() == 0 || geteuid() == 0) #endif /* HAVE_CYGWIN */ + { + #ifdef HAVE_SETPCRED - setpcred(pw->pw_name); + if (setpcred(pw->pw_name, (char **)NULL) == -1) + fatal("Failed to set process credentials"); #endif /* HAVE_SETPCRED */ #ifdef HAVE_LOGIN_CAP # 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_SETPATH)) < 0) { perror("unable to set user context"); @@ -1233,11 +1279,14 @@ 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. */ - do_pam_setcred(0); + 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); @@ -1249,10 +1298,31 @@ do_setusercontext(struct passwd *pw) permanently_set_uid(pw); #endif } + +#ifdef HAVE_CYGWIN + if (is_winnt) +#endif if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) fatal("Failed to set uids to %u.", (u_int) pw->pw_uid); } +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"); + 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) { @@ -1274,6 +1344,40 @@ 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 @@ -1287,11 +1391,18 @@ 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; @@ -1306,12 +1417,19 @@ do_child(Session *s, const char *command) */ if (!options.use_login) { #ifdef HAVE_OSF_SIA - session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); + session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); if (!check_quietlogin(s, command)) do_motd(); #else /* HAVE_OSF_SIA */ 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 (command == NULL) + display_loginmsg(); #endif /* HAVE_OSF_SIA */ } @@ -1320,16 +1438,21 @@ do_child(Session *s, const char *command) * legal, and means /bin/sh. */ shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; + + /* + * Make sure $SHELL points to the shell from the password file, + * even if shell is overridden from login.conf + */ + env = do_setup_env(s, shell); + #ifdef HAVE_LOGIN_CAP shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); #endif - env = do_setup_env(s, shell); - /* we have to stash the hostname before we close our socket. */ if (options.use_login) hostname = get_remote_name_or_ip(utmp_len, - options.verify_reverse_mapping); + options.use_dns); /* * Close the connection descriptors; note that this is the child, and * the server will still have the socket open, and it is important @@ -1337,33 +1460,7 @@ 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(); - - /* - * 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); + child_close_fds(); /* * Must take new environment into use so that .ssh/rc, @@ -1371,17 +1468,31 @@ do_child(Session *s, const char *command) */ environ = env; -#ifdef AFS - /* Try to get AFS tokens for the local cell. */ - if (k_hasafs()) { +#if defined(KRB5) && defined(USE_AFS) + /* + * 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. + */ + + if (options.kerberos_get_afs_token && k_hasafs() && + (s->authctxt->krb5_ctx != NULL)) { char cell[64]; + debug("Getting AFS token"); + + k_setpag(); + if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) - krb_afslog(cell, 0); + krb5_afslog(s->authctxt->krb5_ctx, + s->authctxt->krb5_fwd_ccache, cell, NULL); - krb_afslog(0, 0); + krb5_afslog_home(s->authctxt->krb5_ctx, + s->authctxt->krb5_fwd_ccache, NULL, NULL, pw->pw_dir); } -#endif /* AFS */ +#endif /* Change current directory to the user\'s home directory. */ if (chdir(pw->pw_dir) < 0) { @@ -1504,7 +1615,7 @@ 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; @@ -1584,12 +1695,6 @@ 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); @@ -1626,11 +1731,6 @@ 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); @@ -1652,7 +1752,7 @@ session_subsystem_req(Session *s) int i; packet_check_eom(); - log("subsystem request for %.100s", subsys); + logit("subsystem request for %.100s", subsys); for (i = 0; i < options.num_subsystems; i++) { if (strcmp(subsys, options.subsystem_name[i]) == 0) { @@ -1671,7 +1771,7 @@ session_subsystem_req(Session *s) } if (!success) - log("subsystem request for %.100s failed, subsystem not found", + logit("subsystem request for %.100s failed, subsystem not found", subsys); xfree(subsys); @@ -1718,6 +1818,54 @@ session_exec_req(Session *s) return 1; } +static int +session_break_req(Session *s) +{ + + packet_get_int(); /* ignored */ + packet_check_eom(); + + if (s->ttyfd == -1 || + tcsendbreak(s->ttyfd, 0) < 0) + return 0; + return 1; +} + +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, sizeof(*s->env) * + (s->num_env + 1)); + 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 session_auth_agent_req(Session *s) { @@ -1742,7 +1890,7 @@ session_input_channel_req(Channel *c, const char *rtype) Session *s; if ((s = session_by_channel(c->self)) == NULL) { - log("session_input_channel_req: no session %d req %.100s", + logit("session_input_channel_req: no session %d req %.100s", c->self, rtype); return 0; } @@ -1765,11 +1913,16 @@ 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, "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; } @@ -1796,10 +1949,8 @@ 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; @@ -1830,9 +1981,9 @@ 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 * @@ -1904,11 +2055,11 @@ session_exit_message(Session *s, int status) void session_close(Session *s) { + 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) @@ -1920,6 +2071,12 @@ 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); } @@ -1957,10 +2114,8 @@ 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 */ @@ -1989,13 +2144,22 @@ session_tty_list(void) { static char buf[1024]; int i; + char *cp; + buf[0] = '\0'; 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, strrchr(s->tty, '/') + 1, sizeof buf); + strlcat(buf, cp, sizeof buf); } } if (buf[0] == '\0') @@ -2093,3 +2257,50 @@ 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); +}