X-Git-Url: http://andersk.mit.edu/gitweb/gssapi-openssh.git/blobdiff_plain/5598e598f2b9714c3b08a211d401c780e74dabe2..ebce5315554ed351fb77dfa286a373591d3495f3:/openssh/session.c diff --git a/openssh/session.c b/openssh/session.c index d7e4806..c9b9552 100644 --- a/openssh/session.c +++ b/openssh/session.c @@ -1,3 +1,4 @@ +/* $OpenBSD: session.c,v 1.221 2007/01/21 01:41:54 stevesk Exp $ */ /* * Copyright (c) 1995 Tatu Ylonen , Espoo, Finland * All rights reserved @@ -33,20 +34,48 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.108 2001/10/11 13:45:21 markus Exp $"); +#include +#include +#ifdef HAVE_SYS_STAT_H +# include +#endif +#include +#include +#include + +#include + +#include +#include +#ifdef HAVE_PATHS_H +#include +#endif +#include +#include +#include +#include +#include +#include +#include + +#include "xmalloc.h" #include "ssh.h" #include "ssh1.h" #include "ssh2.h" -#include "xmalloc.h" #include "sshpty.h" #include "packet.h" #include "buffer.h" -#include "mpaux.h" +#include "match.h" #include "uidswap.h" #include "compat.h" #include "channels.h" -#include "bufaux.h" +#include "key.h" +#include "cipher.h" +#ifdef GSSAPI +#include "ssh-gss.h" +#endif +#include "hostfile.h" #include "auth.h" #include "auth-options.h" #include "pathnames.h" @@ -56,77 +85,18 @@ RCSID("$OpenBSD: session.c,v 1.108 2001/10/11 13:45:21 markus Exp $"); #include "serverloop.h" #include "canohost.h" #include "session.h" +#include "kex.h" +#include "monitor_wrap.h" -#ifdef GSSAPI -#include "ssh-gss.h" -#endif - -#ifdef WITH_IRIX_PROJECT -#include -#endif /* WITH_IRIX_PROJECT */ -#ifdef WITH_IRIX_JOBS -#include -#endif -#ifdef WITH_IRIX_AUDIT -#include -#endif /* WITH_IRIX_AUDIT */ - -#if defined(HAVE_USERSEC_H) -#include +#if defined(KRB5) && defined(USE_AFS) +#include #endif -#ifdef HAVE_CYGWIN -#include -#include -#define is_winnt (GetVersion() < 0x80000000) -#endif - -/* AIX limits */ -#if defined(HAVE_GETUSERATTR) && !defined(S_UFSIZE_HARD) && defined(S_UFSIZE) -# define S_UFSIZE_HARD S_UFSIZE "_hard" -# define S_UCPU_HARD S_UCPU "_hard" -# define S_UDATA_HARD S_UDATA "_hard" -# define S_USTACK_HARD S_USTACK "_hard" -# define S_URSS_HARD S_URSS "_hard" -# define S_UCORE_HARD S_UCORE "_hard" -# define S_UNOFILE_HARD S_UNOFILE "_hard" -#endif - -#ifdef _AIX -# include -#endif - -/* types */ - -#define TTYSZ 64 -typedef struct Session Session; -struct Session { - int used; - int self; - struct passwd *pw; - Authctxt *authctxt; - pid_t pid; - /* tty */ - char *term; - int ptyfd, ttyfd, ptymaster; - int row, col, xpixel, ypixel; - char tty[TTYSZ]; - /* X11 */ - char *display; - int screen; - char *auth_proto; - char *auth_data; - int single_connection; - /* proto 2 */ - int chanid; - int is_subsystem; -}; - /* func */ Session *session_new(void); void session_set_fds(Session *, int, int, int); -static 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 *); @@ -143,9 +113,13 @@ int check_quietlogin(Session *, const char *); static void do_authenticated1(Authctxt *); static void do_authenticated2(Authctxt *); -static void session_close(Session *); static int session_pty_req(Session *); +#ifdef SESSION_HOOKS +static void execute_session_hook(char* prog, Authctxt *authctxt, + int startup, int save); +#endif + /* import */ extern ServerOptions options; extern char *__progname; @@ -154,6 +128,7 @@ 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; @@ -162,45 +137,108 @@ 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 -static login_cap_t *lc; +login_cap_t *lc; #endif -void -do_authenticated(Authctxt *authctxt) +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; + +/* removes the agent forwarding socket */ + +static void +auth_sock_cleanup_proc(struct passwd *pw) { - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - if (startup_pipe != -1) { - close(startup_pipe); - startup_pipe = -1; - } -#if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD) - if ((lc = login_getclass(authctxt->pw->pw_class)) == NULL) { - error("unable to get login class"); - return; + if (auth_sock_name != NULL) { + temporarily_use_uid(pw); + unlink(auth_sock_name); + rmdir(auth_sock_dir); + auth_sock_name = NULL; + restore_uid(); } -#ifdef BSD_AUTH - if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) { - packet_disconnect("Approval failure for %s", - authctxt->pw->pw_name); +} + +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; } -#endif -#endif -#ifdef WITH_AIXAUTHENTICATE - /* We don't have a pty yet, so just label the line as "ssh" */ - if (loginsuccess(authctxt->user, - get_canonical_hostname(options.reverse_mapping_check), - "ssh", &aixloginmsg) < 0) - aixloginmsg = NULL; -#endif /* WITH_AIXAUTHENTICATE */ + + /* 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-XXXXXXXXXX", 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()); + + /* 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, SSH_LISTEN_BACKLOG) < 0) + packet_disconnect("listen: %.100s", strerror(errno)); + + /* Allocate a channel for the authentication agent socket. */ + /* this shouldn't matter if its hpn or not - cjr */ + nc = channel_new("auth socket", + SSH_CHANNEL_AUTH_SOCKET, sock, sock, -1, + CHAN_X11_WINDOW_DEFAULT, CHAN_X11_PACKET_DEFAULT, + 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); /* setup the channel layer */ if (!no_port_forwarding_flag && options.allow_tcp_forwarding) @@ -211,17 +249,22 @@ do_authenticated(Authctxt *authctxt) else do_authenticated1(authctxt); - /* remove agent socket */ - if (auth_get_socket_name()) - 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); +#ifdef SESSION_HOOKS + if (options.session_hooks_allow && + options.session_hooks_shutdown_cmd) + { + execute_session_hook(options.session_hooks_shutdown_cmd, + authctxt, + /* startup = */ 0, /* save = */ 0); + + if (authctxt->session_env_file) + { + free(authctxt->session_env_file); + } + } #endif + + do_cleanup(authctxt); } /* @@ -235,11 +278,15 @@ do_authenticated1(Authctxt *authctxt) { Session *s; char *command; - int success, type, plen, screen_flag; - int compression_level = 0, enable_compression_after_reply = 0; - u_int proto_len, data_len, dlen; + int success, type, screen_flag; + int enable_compression_after_reply = 0; + 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; @@ -251,16 +298,20 @@ do_authenticated1(Authctxt *authctxt) success = 0; /* Get a packet from the client. */ - type = packet_read(&plen); + type = packet_read(); /* Process the packet. */ switch (type) { case SSH_CMSG_REQUEST_COMPRESSION: - packet_integrity_check(plen, 4, type); compression_level = packet_get_int(); + packet_check_eom(); if (compression_level < 1 || compression_level > 9) { - packet_send_debug("Received illegal compression level %d.", - compression_level); + packet_send_debug("Received invalid compression level %d.", + compression_level); + break; + } + if (options.compression == COMP_NONE) { + debug2("compression disabled"); break; } /* Enable compression after we have responded with SUCCESS. */ @@ -288,7 +339,7 @@ do_authenticated1(Authctxt *authctxt) } else { s->screen = 0; } - packet_done(); + packet_check_eom(); success = session_setup_x11fwd(s); if (!success) { xfree(s->auth_proto); @@ -317,7 +368,12 @@ do_authenticated1(Authctxt *authctxt) break; } debug("Received TCP/IP port forwarding request."); - channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); + if (channel_input_port_forward_request(s->pw->pw_uid == 0, + options.gateway_ports, options.hpn_disabled, + options.hpn_buffer_size) < 0) { + debug("Port forwarding failed."); + break; + } success = 1; break; @@ -325,58 +381,6 @@ do_authenticated1(Authctxt *authctxt) if (packet_set_maxsize(packet_get_int()) > 0) 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_integrity_check(plen, 4 + dlen, type); - - /* 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_integrity_check(plen, 4 + dlen, type); - - 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: @@ -388,7 +392,7 @@ do_authenticated1(Authctxt *authctxt) } else { do_exec(s, NULL); } - packet_done(); + packet_check_eom(); session_close(s); return; @@ -397,7 +401,7 @@ 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(); @@ -419,7 +423,7 @@ 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]; @@ -440,22 +444,15 @@ do_exec_no_pty(Session *s, const char *command) session_proctitle(s); -#if defined(GSSAPI) - temporarily_use_uid(s->pw); - ssh_gssapi_storecreds(); - restore_uid(); -#endif - #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) { + is_child = 1; + /* Child. Reinitialize the log since the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); @@ -503,10 +500,17 @@ do_exec_no_pty(Session *s, const char *command) perror("dup2 stderr"); #endif /* USE_PIPES */ +#ifdef _UNICOS + cray_init_job(s->pw); /* set up cray jid and tmpdir */ +#endif + /* Do processing for the child (exec command etc). */ do_child(s, command); /* NOTREACHED */ } +#ifdef _UNICOS + signal(WJSIGNAL, cray_job_termination_handler); +#endif /* _UNICOS */ #ifdef HAVE_CYGWIN if (is_winnt) cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); @@ -523,7 +527,11 @@ 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]); @@ -534,6 +542,13 @@ 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. @@ -564,19 +579,17 @@ do_exec_pty(Session *s, const char *command) ptyfd = s->ptyfd; ttyfd = s->ttyfd; -#if defined(GSSAPI) - temporarily_use_uid(s->pw); - ssh_gssapi_storecreds(); - restore_uid(); -#endif - #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) { + is_child = 1; /* Child. Reinitialize the log because the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); @@ -599,8 +612,12 @@ do_exec_pty(Session *s, const char *command) /* record login, etc. similar to login(1) */ #ifndef HAVE_OSF_SIA - if (!(options.use_login && command == NULL)) + if (!(options.use_login && command == NULL)) { +#ifdef _UNICOS + cray_init_job(s->pw); /* set up cray jid and tmpdir */ +#endif /* _UNICOS */ do_login(s, command); + } # ifdef LOGIN_NEEDS_UTMPX else do_pre_login(s); @@ -611,6 +628,9 @@ do_exec_pty(Session *s, const char *command) do_child(s, command); /* NOTREACHED */ } +#ifdef _UNICOS + signal(WJSIGNAL, cray_job_termination_handler); +#endif /* _UNICOS */ #ifdef HAVE_CYGWIN if (is_winnt) cygwin_set_impersonation_token(INVALID_HANDLE_VALUE); @@ -660,18 +680,18 @@ do_pre_login(Session *s) * 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) { + (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.reverse_mapping_check), - (struct sockaddr *)&from); + get_remote_name_or_ip(utmp_len, options.use_dns), + (struct sockaddr *)&from, fromlen); } #endif @@ -682,11 +702,47 @@ do_pre_login(Session *s) void do_exec(Session *s, const char *command) { - if (forced_command) { + if (options.adm_forced_command) { + original_command = command; + command = options.adm_forced_command; + debug("Forced command (config) '%.900s'", command); + } else if (forced_command) { original_command = command; command = forced_command; - debug("Forced command '%.900s'", command); + debug("Forced command (key option) '%.900s'", command); + } + +#if defined(SESSION_HOOKS) + if (options.session_hooks_allow && + (options.session_hooks_startup_cmd || + options.session_hooks_shutdown_cmd)) + { + char env_file[1000]; + struct stat st; + do + { + snprintf(env_file, + sizeof(env_file), + "/tmp/ssh_env_%d%d%d", + getuid(), + getpid(), + rand()); + } while (stat(env_file, &st)==0); + s->authctxt->session_env_file = strdup(env_file); + } +#endif + +#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); @@ -694,17 +750,21 @@ do_exec(Session *s, const char *command) do_exec_no_pty(s, command); original_command = NULL; + + /* + * Clear loginmsg: it's the child's responsibility to display + * it to the user, otherwise multiple sessions may accumulate + * multiple copies of the login messages. + */ + buffer_clear(&loginmsg); } /* administrative, login(1)-like work */ void do_login(Session *s, const char *command) { - char *time_string; - char hostname[MAXHOSTNAMELEN]; socklen_t fromlen; struct sockaddr_storage from; - time_t last_login_time; struct passwd * pw = s->pw; pid_t pid = getpid(); @@ -713,59 +773,39 @@ 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) { + (struct sockaddr *) & from, &fromlen) < 0) { debug("getpeername: %.100s", strerror(errno)); - fatal_cleanup(); + cleanup_exit(255); } } - /* Get the time and hostname when the user last logged in. */ - if (options.print_lastlog) { - hostname[0] = '\0'; - last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, - hostname, sizeof(hostname)); - } - /* Record that there was a login on that tty from the remote host. */ - record_login(pid, s->tty, pw->pw_name, pw->pw_uid, - get_remote_name_or_ip(utmp_len, options.reverse_mapping_check), - (struct sockaddr *)&from); + if (!use_privsep) + record_login(pid, s->tty, pw->pw_name, pw->pw_uid, + get_remote_name_or_ip(utmp_len, + options.use_dns), + (struct sockaddr *)&from, fromlen); #ifdef USE_PAM /* * 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 */ - - if (options.print_lastlog && last_login_time != 0) { - time_string = ctime(&last_login_time); - if (strchr(time_string, '\n')) - *strchr(time_string, '\n') = 0; - if (strcmp(hostname, "") == 0) - printf("Last login: %s\r\n", time_string); - else - printf("Last login: %s from %s\r\n", time_string, hostname); - } + display_loginmsg(); do_motd(); } @@ -825,10 +865,21 @@ check_quietlogin(Session *s, const char *command) */ void child_set_env(char ***envp, u_int *envsizep, const char *name, - const char *value) + 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 @@ -845,9 +896,13 @@ child_set_env(char ***envp, u_int *envsizep, const char *name, xfree(env[i]); } else { /* New variable. Expand if necessary. */ - if (i >= (*envsizep) - 1) { - (*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; @@ -866,17 +921,20 @@ child_set_env(char ***envp, u_int *envsizep, const char *name, */ static void read_environment_file(char ***env, u_int *envsize, - const char *filename) + const char *filename) { 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') @@ -885,7 +943,8 @@ 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; } /* @@ -899,330 +958,210 @@ read_environment_file(char ***env, u_int *envsize, fclose(f); } -#ifdef USE_PAM -/* - * Sets any environment variables which have been specified by PAM - */ -void do_pam_environment(char ***env, u_int *envsize) -{ - char *equals, var_name[512], var_val[512]; - char **pam_env; - int i; - - if ((pam_env = fetch_pam_environment()) == NULL) - return; - - for(i = 0; pam_env[i] != NULL; i++) { - if ((equals = strstr(pam_env[i], "=")) == NULL) - continue; +#ifdef SESSION_HOOKS +#define SSH_SESSION_ENV_FILE "SSH_SESSION_ENV_FILE" - if (strlen(pam_env[i]) < (sizeof(var_name) - 1)) { - memset(var_name, '\0', sizeof(var_name)); - memset(var_val, '\0', sizeof(var_val)); +typedef enum { no_op, execute, clear_env, restore_env, + read_env, save_or_rm_env } session_action_t; - strncpy(var_name, pam_env[i], equals - pam_env[i]); - strcpy(var_val, equals + 1); +static session_action_t action_order[2][5] = { + { clear_env, read_env, execute, save_or_rm_env, restore_env }, /*shutdown*/ + { execute, read_env, save_or_rm_env, no_op, no_op } /*startup */ +}; - debug3("PAM environment: %s=%s", var_name, var_val); +static +void execute_session_hook(char* prog, Authctxt *authctxt, + int startup, int save) +{ + extern char **environ; + + struct stat st; + char **saved_env, **tmpenv; + char *env_file = authctxt->session_env_file; + int i, status = 0; + + for (i=0; i<5; i++) + { + switch (action_order[startup][i]) + { + case no_op: + break; + + case execute: + { + FILE* fp; + char buf[1000]; + + snprintf(buf, + sizeof(buf), + "%s -c '%s'", + authctxt->pw->pw_shell, + prog); + + debug("executing session hook: [%s]", buf); + setenv(SSH_SESSION_ENV_FILE, env_file, /* overwrite = */ 1); + + /* flusing is recommended in the popen(3) man page, to avoid + intermingling of output */ + fflush(stdout); + fflush(stderr); + if ((fp=popen(buf, "w")) == NULL) + { + perror("Unable to run session hook"); + return; + } + status = pclose(fp); + debug2("session hook executed, status=%d", status); + unsetenv(SSH_SESSION_ENV_FILE); + } + break; + + case clear_env: + saved_env = environ; + tmpenv = (char**) malloc(sizeof(char*)); + tmpenv[0] = NULL; + environ = tmpenv; + break; + + case restore_env: + environ = saved_env; + free(tmpenv); + break; + + case read_env: + if (status==0 && stat(env_file, &st)==0) + { + int envsize = 0; + + debug("reading environment from %s", env_file); + while (environ[envsize++]) ; + read_environment_file(&environ, &envsize, env_file); + } + break; + + case save_or_rm_env: + if (status==0 && save) + { + FILE* fp; + int envcount=0; + + debug2("saving environment to %s", env_file); + if ((fp = fopen(env_file, "w")) == NULL) /* hmm: file perms? */ + { + perror("Unable to save session hook info"); + } + while (environ[envcount]) + { + fprintf(fp, "%s\n", environ[envcount++]); + } + fflush(fp); + fclose(fp); + } + else if (stat(env_file, &st)==0) + { + debug2("removing environment file %s", env_file); + remove(env_file); + } + break; + } + } - child_set_env(env, envsize, var_name, var_val); - } - } } -#endif /* USE_PAM */ +#endif -#ifdef HAVE_CYGWIN -void copy_environment(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) { - char *equals, var_name[512], var_val[512]; int i; + size_t len; - for(i = 0; environ[i] != NULL; i++) { - if ((equals = strstr(environ[i], "=")) == NULL) - continue; - - if (strlen(environ[i]) < (sizeof(var_name) - 1)) { - memset(var_name, '\0', sizeof(var_name)); - memset(var_val, '\0', sizeof(var_val)); - - strncpy(var_name, environ[i], equals - environ[i]); - strcpy(var_val, equals + 1); - - debug3("Copy environment: %s=%s", var_name, var_val); - - child_set_env(env, envsize, var_name, var_val); - } - } + 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; } -#endif -#if defined(HAVE_GETUSERATTR) /* - * AIX-specific login initialisation + * Read /etc/default/login. + * We pick up the PATH (or SUPATH for root) and UMASK. */ -void set_limit(char *user, char *soft, char *hard, int resource, int mult) +static void +read_etc_default_login(char ***env, u_int *envsize, uid_t uid) { - struct rlimit rlim; - int slim, hlim; - - getrlimit(resource, &rlim); - - slim = 0; - if (getuserattr(user, soft, &slim, SEC_INT) != -1) { - if (slim < 0) { - rlim.rlim_cur = RLIM_INFINITY; - } else if (slim != 0) { - /* See the wackiness below */ - if (rlim.rlim_cur == slim * mult) - slim = 0; - else - rlim.rlim_cur = slim * mult; - } - } - - hlim = 0; - if (getuserattr(user, hard, &hlim, SEC_INT) != -1) { - if (hlim < 0) { - rlim.rlim_max = RLIM_INFINITY; - } else if (hlim != 0) { - rlim.rlim_max = hlim * mult; - } - } + char **tmpenv = NULL, *var; + u_int i, tmpenvsize = 0; + u_long mask; /* - * XXX For cpu and fsize the soft limit is set to the hard limit - * if the hard limit is left at its default value and the soft limit - * is changed from its default value, either by requesting it - * (slim == 0) or by setting it to the current default. At least - * that's how rlogind does it. If you're confused you're not alone. - * Bug or feature? AIX 4.3.1.2 + * 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. */ - if ((!strcmp(soft, "fsize") || !strcmp(soft, "cpu")) - && hlim == 0 && slim != 0) - rlim.rlim_max = rlim.rlim_cur; - /* A specified hard limit limits the soft limit */ - else if (hlim > 0 && rlim.rlim_cur > rlim.rlim_max) - rlim.rlim_cur = rlim.rlim_max; - /* A soft limit can increase a hard limit */ - else if (rlim.rlim_cur > rlim.rlim_max) - rlim.rlim_max = rlim.rlim_cur; - - if (setrlimit(resource, &rlim) != 0) - error("setrlimit(%.10s) failed: %.100s", soft, strerror(errno)); -} + read_environment_file(&tmpenv, &tmpenvsize, "/etc/default/login"); -void set_limits_from_userattr(char *user) -{ - int mask; - char buf[16]; - - set_limit(user, S_UFSIZE, S_UFSIZE_HARD, RLIMIT_FSIZE, 512); - set_limit(user, S_UCPU, S_UCPU_HARD, RLIMIT_CPU, 1); - set_limit(user, S_UDATA, S_UDATA_HARD, RLIMIT_DATA, 512); - set_limit(user, S_USTACK, S_USTACK_HARD, RLIMIT_STACK, 512); - set_limit(user, S_URSS, S_URSS_HARD, RLIMIT_RSS, 512); - set_limit(user, S_UCORE, S_UCORE_HARD, RLIMIT_CORE, 512); -#if defined(S_UNOFILE) - set_limit(user, S_UNOFILE, S_UNOFILE_HARD, RLIMIT_NOFILE, 1); -#endif + if (tmpenv == NULL) + return; - if (getuserattr(user, S_UMASK, &mask, SEC_INT) != -1) { - /* Convert decimal to octal */ - (void) snprintf(buf, sizeof(buf), "%d", mask); - if (sscanf(buf, "%o", &mask) == 1) - umask(mask); - } + 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 /* defined(HAVE_GETUSERATTR) */ +#endif /* HAVE_ETC_DEFAULT_LOGIN */ -/* - * Performs common processing for the child, such as setting up the - * environment, closing extra file descriptors, setting the user and group - * ids, and executing the command or shell. - */ void -do_child(Session *s, const char *command) +copy_environment(char **source, char ***env, u_int *envsize) { - const char *shell, *hostname = NULL, *cp = NULL; - struct passwd *pw = s->pw; - char buf[256]; - char cmd[1024]; - FILE *f = NULL; - u_int envsize, i; - char **env; - extern char **environ; - struct stat st; - char *argv[10]; - int do_xauth; -#ifdef WITH_IRIX_PROJECT - prid_t projid; -#endif /* WITH_IRIX_PROJECT */ -#ifdef WITH_IRIX_JOBS - jid_t jid = 0; -#else -#ifdef WITH_IRIX_ARRAY - int jid = 0; -#endif /* WITH_IRIX_ARRAY */ -#endif /* WITH_IRIX_JOBS */ - - do_xauth = - s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; - - /* remove hostkey from the child's memory */ - destroy_sensitive_data(); + char *var_name, *var_val; + int i; - /* login(1) is only called if we execute the login shell */ - if (options.use_login && command != NULL) - options.use_login = 0; + if (source == NULL) + return; -#if !defined(HAVE_OSF_SIA) - if (!options.use_login) { -# ifdef HAVE_LOGIN_CAP - if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) - f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, - _PATH_NOLOGIN), "r"); -# else /* HAVE_LOGIN_CAP */ - if (pw->pw_uid) - f = fopen(_PATH_NOLOGIN, "r"); -# endif /* HAVE_LOGIN_CAP */ - if (f) { - /* /etc/nologin exists. Print its contents and exit. */ - while (fgets(buf, sizeof(buf), f)) - fputs(buf, stderr); - fclose(f); - exit(254); + for(i = 0; source[i] != NULL; i++) { + var_name = xstrdup(source[i]); + if ((var_val = strstr(var_name, "=")) == NULL) { + xfree(var_name); + continue; } - } -#endif /* HAVE_OSF_SIA */ - - /* Set login name, uid, gid, and groups. */ - /* Login(1) does this as well, and it needs uid 0 for the "-h" - switch, so we let login(1) to this for us. */ - if (!options.use_login) { -#ifdef HAVE_OSF_SIA - session_setup_sia(pw->pw_name, s->ttyfd == -1 ? NULL : s->tty); - if (!check_quietlogin(s, command)) - do_motd(); -#else /* HAVE_OSF_SIA */ -#ifdef HAVE_CYGWIN - if (is_winnt) { -#else - if (getuid() == 0 || geteuid() == 0) { -#endif -# ifdef HAVE_GETUSERATTR - set_limits_from_userattr(pw->pw_name); -# endif /* HAVE_GETUSERATTR */ -# ifdef HAVE_LOGIN_CAP - if (setusercontext(lc, pw, pw->pw_uid, - (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { - perror("unable to set user context"); - exit(1); - } -# else /* HAVE_LOGIN_CAP */ -#if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) - /* Sets login uid for accounting */ - if (getluid() == -1 && setluid(pw->pw_uid) == -1) - error("setluid: %s", strerror(errno)); -#endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ - - if (setlogin(pw->pw_name) < 0) - error("setlogin failed: %s", strerror(errno)); - if (setgid(pw->pw_gid) < 0) { - perror("setgid"); - exit(1); - } - /* Initialize the group list. */ - if (initgroups(pw->pw_name, pw->pw_gid) < 0) { - perror("initgroups"); - exit(1); - } - endgrent(); - -# ifdef USE_PAM - /* - * 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); -# endif /* USE_PAM */ -# ifdef WITH_IRIX_JOBS - jid = jlimit_startjob(pw->pw_name, pw->pw_uid, "interactive"); - if (jid == -1) { - fatal("Failed to create job container: %.100s", - strerror(errno)); - } -# endif /* WITH_IRIX_JOBS */ -# ifdef WITH_IRIX_ARRAY - /* initialize array session */ - if (jid == 0) { - if (newarraysess() != 0) - fatal("Failed to set up new array session: %.100s", - strerror(errno)); - } -# endif /* WITH_IRIX_ARRAY */ -# ifdef WITH_IRIX_PROJECT - /* initialize irix project info */ - if ((projid = getdfltprojuser(pw->pw_name)) == -1) { - debug("Failed to get project id, using projid 0"); - projid = 0; - } - if (setprid(projid)) - fatal("Failed to initialize project %d for %s: %.100s", - (int)projid, pw->pw_name, strerror(errno)); -# endif /* WITH_IRIX_PROJECT */ -#ifdef WITH_IRIX_AUDIT - if (sysconf(_SC_AUDIT)) { - debug("Setting sat id to %d", (int) pw->pw_uid); - if (satsetid(pw->pw_uid)) - debug("error setting satid: %.100s", strerror(errno)); - } -#endif /* WITH_IRIX_AUDIT */ - -#ifdef _AIX - /* - * AIX has a "usrinfo" area where logname and - * other stuff is stored - a few applications - * actually use this and die if it's not set - */ - if (s->ttyfd == -1) - s->tty[0] = '\0'; - cp = xmalloc(22 + strlen(s->tty) + - 2 * strlen(pw->pw_name)); - i = sprintf(cp, "LOGNAME=%s%cNAME=%s%cTTY=%s%c%c", - pw->pw_name, 0, pw->pw_name, 0, s->tty, 0, 0); - if (usrinfo(SETUINFO, cp, i) == -1) - fatal("Couldn't set usrinfo: %s", - strerror(errno)); - debug3("AIX/UsrInfo: set len %d", i); - xfree(cp); -#endif + *var_val++ = '\0'; - /* Permanently switch to the desired uid. */ - permanently_set_uid(pw); -# endif /* HAVE_LOGIN_CAP */ - } -#endif /* HAVE_OSF_SIA */ + debug3("Copy environment: %s=%s", var_name, var_val); + child_set_env(env, envsize, var_name, var_val); -#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); + xfree(var_name); } - /* - * Get the shell from the password data. An empty shell field is - * legal, and means /bin/sh. - */ - shell = (pw->pw_shell[0] == '\0') ? _PATH_BSHELL : pw->pw_shell; -#ifdef HAVE_LOGIN_CAP - shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); +} + +static char ** +do_setup_env(Session *s, const char *shell) +{ + char buf[256]; + u_int i, envsize; + char **env, *laddr; + struct passwd *pw = s->pw; +#ifndef HAVE_LOGIN_CAP + char *path = NULL; #endif /* Initialize the environment. */ envsize = 100; - env = xmalloc(envsize * sizeof(char *)); + env = xcalloc(envsize, sizeof(char *)); env[0] = NULL; #ifdef HAVE_CYGWIN @@ -1230,24 +1169,39 @@ do_child(Session *s, const char *command) * The Windows environment contains some setting which are * important for a running system. They must not be dropped. */ - copy_environment(&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 + /* Allow any GSSAPI methods that we've used to alter * the childs environment as they see fit */ - ssh_gssapi_do_child(&env,&envsize); + 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 - (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 /* @@ -1256,7 +1210,15 @@ do_child(Session *s, const char *command) * needed for loading shared libraries. So the path better * remains intact here. */ - child_set_env(&env, &envsize, "PATH", _PATH_STDPATH); +# 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 */ @@ -1270,17 +1232,34 @@ do_child(Session *s, const char *command) if (getenv("TZ")) child_set_env(&env, &envsize, "TZ", getenv("TZ")); +#ifdef GSI /* GSI shared libs typically installed in non-system locations. */ + { + char *cp; + + if ((cp = getenv("LD_LIBRARY_PATH")) != NULL) + child_set_env(&env, &envsize, "LD_LIBRARY_PATH", cp); + if ((cp = getenv("LIBPATH")) != NULL) + child_set_env(&env, &envsize, "LIBPATH", cp); + if ((cp = getenv("SHLIB_PATH")) != NULL) + child_set_env(&env, &envsize, "SHLIB_PATH", cp); + if ((cp = getenv("LD_LIBRARYN32_PATH")) != NULL) + child_set_env(&env, &envsize, "LD_LIBRARYN32_PATH",cp); + if ((cp = getenv("LD_LIBRARY64_PATH")) != NULL) + child_set_env(&env, &envsize, "LD_LIBRARY64_PATH",cp); + } +#endif + /* Set custom environment options from RSA authentication. */ if (!options.use_login) { while (custom_environment) { struct envstring *ce = custom_environment; - char *s = ce->s; - int i; - for (i = 0; s[i] != '=' && s[i]; i++) + char *str = ce->s; + + 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); @@ -1288,10 +1267,17 @@ do_child(Session *s, const char *command) } } + /* SSH_CLIENT deprecated */ snprintf(buf, sizeof buf, "%.50s %d %d", - get_remote_ipaddr(), get_remote_port(), get_local_port()); + 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(), laddr, get_local_port()); + xfree(laddr); + child_set_env(&env, &envsize, "SSH_CONNECTION", buf); + if (s->ttyfd != -1) child_set_env(&env, &envsize, "SSH_TTY", s->tty); if (s->term) @@ -1302,36 +1288,63 @@ do_child(Session *s, const char *command) child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", original_command); +#ifdef _UNICOS + if (cray_tmpdir[0] != '\0') + 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 - 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 KRB4 - if (s->authctxt->krb4_ticket_file) - child_set_env(&env, &envsize, "KRBTKFILE", - s->authctxt->krb4_ticket_file); + { + char *cp; + + if ((cp = getenv("AUTHSTATE")) != NULL) + child_set_env(&env, &envsize, "AUTHSTATE", 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 - /* Pull in any environment variables that may have been set by PAM. */ - do_pam_environment(&env, &envsize); + /* + * 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); + } #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); + strcmp(pw->pw_dir, "/") ? pw->pw_dir : ""); read_environment_file(&env, &envsize, buf); } if (debug_flag) { @@ -1340,17 +1353,253 @@ do_child(Session *s, const char *command) for (i = 0; env[i]; i++) fprintf(stderr, " %.200s\n", env[i]); } - /* we have to stash the hostname before we close our socket. */ - if (options.use_login) - hostname = get_remote_name_or_ip(utmp_len, - options.reverse_mapping_check); - /* - * Close the connection descriptors; note that this is the child, and - * the server will still have the socket open, and it is important - * that we do not shutdown it. Note that the descriptors cannot be - * closed before building the environment, as we call - * get_remote_ipaddr there. - */ + return env; +} + +/* + * Run $HOME/.ssh/rc, /etc/ssh/sshrc, or xauth (whichever is found + * first in this order). + */ +static void +do_rc_files(Session *s, const char *shell) +{ + FILE *f = NULL; + char cmd[1024]; + int do_xauth; + struct stat st; + + do_xauth = + s->display != NULL && s->auth_proto != NULL && s->auth_data != NULL; + + /* ignore _PATH_SSH_USER_RC for subsystems */ + if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { + snprintf(cmd, sizeof cmd, "%s -c '%s %s'", + shell, _PATH_BSHELL, _PATH_SSH_USER_RC); + if (debug_flag) + fprintf(stderr, "Running %s\n", cmd); + f = popen(cmd, "w"); + if (f) { + if (do_xauth) + fprintf(f, "%s %s\n", s->auth_proto, + s->auth_data); + pclose(f); + } else + fprintf(stderr, "Could not run %s\n", + _PATH_SSH_USER_RC); + } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { + if (debug_flag) + fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, + _PATH_SSH_SYSTEM_RC); + f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); + if (f) { + if (do_xauth) + fprintf(f, "%s %s\n", s->auth_proto, + s->auth_data); + pclose(f); + } else + fprintf(stderr, "Could not run %s\n", + _PATH_SSH_SYSTEM_RC); + } else if (do_xauth && options.xauth_location != NULL) { + /* Add authority data to .Xauthority if appropriate. */ + if (debug_flag) { + fprintf(stderr, + "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); + } + snprintf(cmd, sizeof cmd, "%s -q -", + 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); + pclose(f); + } else { + fprintf(stderr, "Could not run %s\n", + cmd); + } + } +} + +static void +do_nologin(struct passwd *pw) +{ + FILE *f = NULL; + char buf[1024]; + +#ifdef HAVE_LOGIN_CAP + if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) + f = fopen(login_getcapstr(lc, "nologin", _PATH_NOLOGIN, + _PATH_NOLOGIN), "r"); +#else + if (pw->pw_uid) + f = fopen(_PATH_NOLOGIN, "r"); +#endif + if (f) { + /* /etc/nologin exists. Print its contents and exit. */ + 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); + } +} + +/* Set login name, uid, gid, and groups. */ +void +do_setusercontext(struct passwd *pw) +{ +#ifndef HAVE_CYGWIN + if (getuid() == 0 || geteuid() == 0) +#endif /* HAVE_CYGWIN */ + { + +#ifdef HAVE_SETPCRED + 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 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(use_privsep); + } +# endif /* USE_PAM */ + if (setusercontext(lc, pw, pw->pw_uid, + (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { + perror("unable to set user context"); + exit(1); + } +#else +# if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) + /* Sets login uid for accounting */ + if (getluid() == -1 && setluid(pw->pw_uid) == -1) + error("setluid: %s", strerror(errno)); +# endif /* defined(HAVE_GETLUID) && defined(HAVE_SETLUID) */ + + if (setlogin(pw->pw_name) < 0) + error("setlogin failed: %s", strerror(errno)); + if (setgid(pw->pw_gid) < 0) { + perror("setgid"); + exit(1); + } + /* Initialize the group list. */ + if (initgroups(pw->pw_name, pw->pw_gid) < 0) { + perror("initgroups"); + 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. + * These will have been wiped by the above initgroups() call. + * Reestablish them here. + */ + if (options.use_pam) { + do_pam_session(); + do_pam_setcred(use_privsep); + } +# endif /* USE_PAM */ +# 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 */ +#ifdef USE_LIBIAF + if (set_id(pw->pw_name) != 0) { + exit(1); + } +#endif /* USE_LIBIAF */ + /* Permanently switch to the desired uid. */ + 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); + +#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 +launch_login(struct passwd *pw, const char *hostname) +{ + /* Launch login(1). */ + + execl(LOGIN_PROGRAM, "login", "-h", hostname, +#ifdef xxxLOGIN_NEEDS_TERM + (s->term ? s->term : "unknown"), +#endif /* LOGIN_NEEDS_TERM */ +#ifdef LOGIN_NO_ENDOPT + "-p", "-f", pw->pw_name, (char *)NULL); +#else + "-p", "-f", "--", pw->pw_name, (char *)NULL); +#endif + + /* Login couldn't be executed, die. */ + + perror("login"); + 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 { @@ -1371,33 +1620,189 @@ do_child(Session *s, const char *command) endpwent(); /* - * Close any extra open file descriptors so that we don\'t have them + * Close any extra open file descriptors so that we don't have them * hanging around in clients. Note that we want to do this after * initgroups, because at least on Solaris 2.3 it leaves file * descriptors open. */ 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 + * ids, and executing the command or shell. + */ +void +do_child(Session *s, const char *command) +{ + extern char **environ; + char **env; + char *argv[10]; + const char *shell, *shell0, *hostname = NULL; + struct passwd *pw = s->pw; + +#ifdef AFS_KRB5 +/* Default place to look for aklog. */ +#ifdef AKLOG_PATH +#define KPROGDIR AKLOG_PATH +#else +#define KPROGDIR "/usr/bin/aklog" +#endif /* AKLOG_PATH */ + + struct stat st; + char *aklog_path; +#endif /* AFS_KRB5 */ + + /* 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; + +#ifdef _UNICOS + cray_setup(pw->pw_uid, pw->pw_name, command); +#endif /* _UNICOS */ /* - * Must take new environment into use so that .ssh/rc, /etc/sshrc and - * xauth are run in the proper environment. + * Login(1) does this as well, and it needs uid 0 for the "-h" + * switch, so we let login(1) to this for us. + */ + if (!options.use_login) { +#ifdef HAVE_OSF_SIA + session_setup_sia(pw, s->ttyfd == -1 ? NULL : s->tty); + if (!check_quietlogin(s, command)) + do_motd(); +#else /* HAVE_OSF_SIA */ + /* 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. + */ + 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 + + /* we have to stash the hostname before we close our socket. */ + if (options.use_login) + hostname = get_remote_name_or_ip(utmp_len, + 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 + * that we do not shutdown it. Note that the descriptors cannot be + * closed before building the environment, as we call + * get_remote_ipaddr there. + */ + child_close_fds(); + + /* + * Must take new environment into use so that .ssh/rc, + * /etc/ssh/sshrc and xauth are run in the proper environment. */ 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); - - krb_afslog(0, 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 /* AFS */ +#endif + +#ifdef AFS_KRB5 - /* Change current directory to the user\'s home directory. */ + /* User has authenticated, and if a ticket was going to be + * passed we would have it. KRB5CCNAME should already be set. + * Now try to get an AFS token using aklog. + */ + if (k_hasafs()) { /* Do we have AFS? */ + + aklog_path = xstrdup(KPROGDIR); + + /* + * Make sure it exists before we try to run it + */ + if (stat(aklog_path, &st) == 0) { + debug("Running %s to get afs token.",aklog_path); + system(aklog_path); + } else { + debug("%s does not exist.",aklog_path); + } + + xfree(aklog_path); + } +#endif /* AFS_KRB5 */ + +#ifdef SESSION_HOOKS + if (options.session_hooks_allow && + options.session_hooks_startup_cmd) + { + execute_session_hook(options.session_hooks_startup_cmd, + s->authctxt, + /* startup = */ 1, + options.session_hooks_shutdown_cmd != NULL); + } +#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)); @@ -1407,84 +1812,22 @@ do_child(Session *s, const char *command) #endif } - /* - * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first - * in this order). - */ - if (!options.use_login) { - /* ignore _PATH_SSH_USER_RC for subsystems */ - if (!s->is_subsystem && (stat(_PATH_SSH_USER_RC, &st) >= 0)) { - snprintf(cmd, sizeof cmd, "%s -c '%s %s'", - shell, _PATH_BSHELL, _PATH_SSH_USER_RC); - if (debug_flag) - fprintf(stderr, "Running %s\n", cmd); - f = popen(cmd, "w"); - if (f) { - if (do_xauth) - fprintf(f, "%s %s\n", s->auth_proto, - s->auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", - _PATH_SSH_USER_RC); - } else if (stat(_PATH_SSH_SYSTEM_RC, &st) >= 0) { - if (debug_flag) - fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, - _PATH_SSH_SYSTEM_RC); - f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); - if (f) { - if (do_xauth) - fprintf(f, "%s %s\n", s->auth_proto, - s->auth_data); - pclose(f); - } else - fprintf(stderr, "Could not run %s\n", - _PATH_SSH_SYSTEM_RC); - } else if (do_xauth && options.xauth_location != NULL) { - /* Add authority data to .Xauthority if appropriate. */ - char *screen = strchr(s->display, ':'); - - if (debug_flag) { - fprintf(stderr, - "Running %.100s add " - "%.100s %.100s %.100s\n", - options.xauth_location, s->display, - s->auth_proto, s->auth_data); - if (screen != NULL) - fprintf(stderr, - "Adding %.*s/unix%s %s %s\n", - (int)(screen - s->display), - s->display, screen, - s->auth_proto, s->auth_data); - } - snprintf(cmd, sizeof cmd, "%s -q -", - options.xauth_location); - f = popen(cmd, "w"); - if (f) { - fprintf(f, "add %s %s %s\n", s->display, - s->auth_proto, s->auth_data); - if (screen != NULL) - fprintf(f, "add %.*s/unix%s %s %s\n", - (int)(screen - s->display), - s->display, screen, - s->auth_proto, - s->auth_data); - pclose(f); - } else { - fprintf(stderr, "Could not run %s\n", - cmd); - } - } - /* Get the last component of the shell name. */ - cp = strrchr(shell, '/'); - if (cp) - cp++; - else - cp = shell; - } + if (!options.use_login) + do_rc_files(s, shell); /* restore SIGPIPE for child */ - signal(SIGPIPE, SIG_DFL); + signal(SIGPIPE, SIG_DFL); + + if (options.use_login) { + launch_login(pw, hostname); + /* NEVERREACHED */ + } + + /* Get the last component of the shell name. */ + if ((shell0 = strrchr(shell, '/')) != NULL) + shell0++; + else + shell0 = shell; /* * If we have no command, execute the shell. In this case, the shell @@ -1492,47 +1835,36 @@ do_child(Session *s, const char *command) * this is a login shell. */ if (!command) { - if (!options.use_login) { - char buf[256]; + char argv0[256]; - /* Start the shell. Set initial character to '-'. */ - buf[0] = '-'; - strncpy(buf + 1, cp, sizeof(buf) - 1); - buf[sizeof(buf) - 1] = 0; + /* Start the shell. Set initial character to '-'. */ + argv0[0] = '-'; - /* Execute the shell. */ - argv[0] = buf; - argv[1] = NULL; - execve(shell, argv, env); - - /* Executing the shell failed. */ + if (strlcpy(argv0 + 1, shell0, sizeof(argv0) - 1) + >= sizeof(argv0) - 1) { + errno = EINVAL; perror(shell); exit(1); + } - } else { - /* Launch login(1). */ - - execl(LOGIN_PROGRAM, "login", "-h", hostname, -#ifdef LOGIN_NEEDS_TERM - s->term? s->term : "unknown", -#endif - "-p", "-f", "--", pw->pw_name, (char *)NULL); - - /* Login couldn't be executed, die. */ + /* Execute the shell. */ + argv[0] = argv0; + argv[1] = NULL; + execve(shell, argv, environ); - perror("login"); - exit(1); - } + /* Executing the shell failed. */ + perror(shell); + exit(1); } /* * Execute the command using the user's shell. This uses the -c * option to execute the command. */ - argv[0] = (char *) cp; + argv[0] = (char *) shell0; argv[1] = "-c"; argv[2] = (char *) command; argv[3] = NULL; - execve(shell, argv, env); + execve(shell, argv, environ); perror(shell); exit(1); } @@ -1544,12 +1876,12 @@ session_new(void) static int did_init = 0; if (!did_init) { debug("session_new: init"); - for(i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < MAX_SESSIONS; i++) { sessions[i].used = 0; } did_init = 1; } - for(i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (! s->used) { memset(s, 0, sizeof(*s)); @@ -1558,6 +1890,7 @@ session_new(void) s->ttyfd = -1; s->used = 1; s->self = i; + s->x11_chanids = NULL; debug("session_new: session %d", i); return s; } @@ -1569,14 +1902,14 @@ static void session_dump(void) { int i; - for(i = 0; i < MAX_SESSIONS; 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); } } @@ -1591,18 +1924,34 @@ 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; return 1; } +Session * +session_by_tty(char *tty) +{ + int i; + for (i = 0; i < MAX_SESSIONS; i++) { + Session *s = &sessions[i]; + if (s->used && s->ttyfd != -1 && strcmp(s->tty, tty) == 0) { + debug("session_by_tty: session %d tty %s", i, tty); + return s; + } + } + debug("session_by_tty: unknown tty %.100s", tty); + session_dump(); + return NULL; +} + static Session * session_by_channel(int id) { int i; - for(i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (s->used && s->chanid == id) { debug("session_by_channel: session %d channel %d", i, id); @@ -1614,17 +1963,40 @@ 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) { int i; - debug("session_by_pid: pid %d", pid); - for(i = 0; i < MAX_SESSIONS; i++) { + 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; } @@ -1636,7 +2008,7 @@ session_window_change_req(Session *s) s->row = packet_get_int(); s->xpixel = packet_get_int(); s->ypixel = packet_get_int(); - packet_done(); + packet_check_eom(); pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); return 1; } @@ -1675,7 +2047,7 @@ session_pty_req(Session *s) /* Allocate a pty and open it. */ debug("Allocating pty."); - if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { + if (!PRIVSEP(pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty)))) { if (s->term) xfree(s->term); s->term = NULL; @@ -1691,17 +2063,13 @@ 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); - pty_setowner(s->pw, s->tty); + if (!use_privsep) + pty_setowner(s->pw, s->tty); /* Set window size from the packet. */ pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); - packet_done(); + packet_check_eom(); session_proctitle(s); return 1; } @@ -1712,17 +2080,18 @@ 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_done(); - log("subsystem request for %s", subsys); + 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; } @@ -1730,11 +2099,12 @@ session_subsystem_req(Session *s) s->is_subsystem = 1; do_exec(s, cmd); success = 1; + break; } } if (!success) - log("subsystem request for %s failed, subsystem not found", + logit("subsystem request for %.100s failed, subsystem not found", subsys); xfree(subsys); @@ -1746,11 +2116,16 @@ 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); s->screen = packet_get_int(); - packet_done(); + packet_check_eom(); success = session_setup_x11fwd(s); if (!success) { @@ -1765,7 +2140,7 @@ session_x11_req(Session *s) static int session_shell_req(Session *s) { - packet_done(); + packet_check_eom(); do_exec(s, NULL); return 1; } @@ -1775,17 +2150,65 @@ session_exec_req(Session *s) { u_int len; char *command = packet_get_string(&len); - packet_done(); + packet_check_eom(); do_exec(s, command); xfree(command); 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, 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 session_auth_agent_req(Session *s) { static int called = 0; - packet_done(); + packet_check_eom(); if (no_agent_forwarding_flag) { debug("session_auth_agent_req: no_agent_forwarding_flag"); return 0; @@ -1798,28 +2221,18 @@ session_auth_agent_req(Session *s) } } -void -session_input_channel_req(int id, void *arg) +int +session_input_channel_req(Channel *c, const char *rtype) { - u_int len; - int reply; int success = 0; - char *rtype; Session *s; - Channel *c; - - rtype = packet_get_string(&len); - reply = packet_get_char(); - s = session_by_channel(id); - if (s == NULL) - fatal("session_input_channel_req: channel %d: no session", id); - c = channel_lookup(id); - if (c == NULL) - fatal("session_input_channel_req: channel %d: bad channel", id); - - debug("session_input_channel_req: session %d channel %d request %s reply %d", - s->self, id, rtype, reply); + if ((s = session_by_channel(c->self)) == NULL) { + logit("session_input_channel_req: no session %d req %.100s", + c->self, rtype); + return 0; + } + debug("session_input_channel_req: session %d req %s", s->self, rtype); /* * a session is in LARVAL state until a shell, a command @@ -1831,26 +2244,24 @@ session_input_channel_req(int id, void *arg) } else if (strcmp(rtype, "exec") == 0) { success = session_exec_req(s); } else if (strcmp(rtype, "pty-req") == 0) { - success = session_pty_req(s); + success = session_pty_req(s); } else if (strcmp(rtype, "x11-req") == 0) { success = session_x11_req(s); } else if (strcmp(rtype, "auth-agent-req@openssh.com") == 0) { 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); } - if (reply) { - packet_start(success ? - SSH2_MSG_CHANNEL_SUCCESS : SSH2_MSG_CHANNEL_FAILURE); - packet_put_int(c->remote_id); - packet_send(); - } - xfree(rtype); + return success; } void @@ -1864,21 +2275,27 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr) */ if (s->chanid == -1) fatal("no channel for session %d", s->self); - channel_set_fds(s->chanid, - fdout, fdin, fderr, - fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, - 1); + if(options.hpn_disabled) + channel_set_fds(s->chanid, + fdout, fdin, fderr, + fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, + 1, + CHAN_SES_WINDOW_DEFAULT); + else + channel_set_fds(s->chanid, + fdout, fdin, fderr, + fderr == -1 ? CHAN_EXTENDED_IGNORE : CHAN_EXTENDED_READ, + 1, + options.hpn_buffer_size); } /* * Function to perform pty cleanup. Also called if we get aborted abnormally * (e.g., due to a dropped connection). */ -static void -session_pty_cleanup(void *session) +void +session_pty_cleanup2(Session *s) { - Session *s = session; - if (s == NULL) { error("session_pty_cleanup: no session"); return; @@ -1890,10 +2307,11 @@ session_pty_cleanup(void *session) /* Record that the user has logged out. */ if (s->pid != 0) - record_logout(s->pid, s->tty); + record_logout(s->pid, s->tty, s->pw->pw_name); /* Release the pseudo-tty. */ - pty_release(s->tty); + if (getuid() == 0) + pty_release(s->tty); /* * Close the server side of the socket pairs. We must do this after @@ -1901,34 +2319,113 @@ session_pty_cleanup(void *session) * while we're still cleaning up. */ if (close(s->ptymaster) < 0) - error("close(s->ptymaster): %s", strerror(errno)); + error("close(s->ptymaster/%d): %s", s->ptymaster, strerror(errno)); /* unlink pty from session */ s->ttyfd = -1; } +void +session_pty_cleanup(Session *s) +{ + PRIVSEP(session_pty_cleanup2(s)); +} + +static char * +sig2name(int sig) +{ +#define SSH_SIG(x) if (sig == SIG ## x) return #x + SSH_SIG(ABRT); + SSH_SIG(ALRM); + SSH_SIG(FPE); + SSH_SIG(HUP); + SSH_SIG(ILL); + SSH_SIG(INT); + SSH_SIG(KILL); + SSH_SIG(PIPE); + SSH_SIG(QUIT); + SSH_SIG(SEGV); + SSH_SIG(TERM); + SSH_SIG(USR1); + SSH_SIG(USR2); +#undef SSH_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) { Channel *c; - if (s == NULL) - fatal("session_close: no session"); - c = channel_lookup(s->chanid); - if (c == NULL) + + 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); + channel_request_start(s->chanid, "exit-status", 0); packet_put_int(WEXITSTATUS(status)); packet_send(); } else if (WIFSIGNALED(status)) { - channel_request_start(s->chanid, - "exit-signal", 0); - packet_put_int(WTERMSIG(status)); + channel_request_start(s->chanid, "exit-signal", 0); + packet_put_cstring(sig2name(WTERMSIG(status))); #ifdef WCOREDUMP packet_put_char(WCOREDUMP(status)); #else /* WCOREDUMP */ @@ -1944,7 +2441,14 @@ 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. @@ -1953,26 +2457,36 @@ session_exit_message(Session *s, int status) */ if (c->ostate != CHAN_OUTPUT_CLOSED) chan_write_failed(c); - s->chanid = -1; } -static void +void session_close(Session *s) { - debug("session_close: session %d pid %d", s->self, s->pid); - if (s->ttyfd != -1) { - fatal_remove_cleanup(session_pty_cleanup, (void *)s); + u_int i; + + debug("session_close: session %d pid %ld", s->self, (long)s->pid); + 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) xfree(s->auth_data); if (s->auth_proto) xfree(s->auth_proto); s->used = 0; + if (s->env != NULL) { + for (i = 0; i < s->num_env; i++) { + xfree(s->env[i].name); + xfree(s->env[i].val); + } + xfree(s->env); + } session_proctitle(s); } @@ -1981,12 +2495,15 @@ 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) session_exit_message(s, status); - session_close(s); + if (s->ttyfd != -1) + session_pty_cleanup(s); + s->pid = 0; } /* @@ -1997,37 +2514,51 @@ 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; } - 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); /* * 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); } void -session_destroy_all(void) +session_destroy_all(void (*closefunc)(Session *)) { int i; - for(i = 0; i < MAX_SESSIONS; i++) { + for (i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; - if (s->used) - session_close(s); + if (s->used) { + if (closefunc != NULL) + closefunc(s); + else + session_close(s); + } } } @@ -2036,13 +2567,22 @@ session_tty_list(void) { static char buf[1024]; int i; + char *cp; + buf[0] = '\0'; - for(i = 0; i < MAX_SESSIONS; i++) { + 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') @@ -2063,6 +2603,9 @@ int 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."); @@ -2086,11 +2629,55 @@ session_setup_x11fwd(Session *s) debug("X11 display already set."); return 0; } - s->display = x11_create_display_inet(s->screen, options.x11_display_offset); - if (s->display == NULL) { + if (x11_create_display_inet(options.x11_display_offset, + options.x11_use_localhost, s->single_connection, + &s->display_number, &s->x11_chanids, + options.hpn_disabled, options.hpn_buffer_size) == -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) + fatal("gethostname: %.100s", strerror(errno)); + /* + * auth_display must be used as the displayname when the + * authorization entry is added with xauth(1). This will be + * different than the DISPLAY string for localhost displays. + */ + if (options.x11_use_localhost) { + snprintf(display, sizeof display, "localhost:%u.%u", + s->display_number, s->screen); + snprintf(auth_display, sizeof auth_display, "unix:%u.%u", + s->display_number, s->screen); + s->display = xstrdup(display); + s->auth_display = xstrdup(auth_display); + } else { +#ifdef IPADDR_IN_DISPLAY + struct hostent *he; + struct in_addr my_addr; + + he = gethostbyname(hostname); + if (he == NULL) { + error("Can't get IP address for X11 DISPLAY."); + packet_send_debug("Can't get IP address for X11 DISPLAY."); + return 0; + } + memcpy(&my_addr, he->h_addr_list[0], sizeof(struct in_addr)); + snprintf(display, sizeof display, "%.50s:%u.%u", inet_ntoa(my_addr), + s->display_number, s->screen); +#else + snprintf(display, sizeof display, "%.400s:%u.%u", hostname, + s->display_number, s->screen); +#endif + s->display = xstrdup(display); + s->auth_display = xstrdup(display); + } + return 1; } @@ -2098,7 +2685,55 @@ static void do_authenticated2(Authctxt *authctxt) { server_loop2(authctxt); -#if defined(GSSAPI) - 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 USE_PAM + if (options.use_pam) { + sshpam_cleanup(); + sshpam_thread_cleanup(); + } +#endif + + if (!authctxt->authenticated) + 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 + + /* 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); }