X-Git-Url: http://andersk.mit.edu/gitweb/openssh.git/blobdiff_plain/0179484859673100ce63b74de5131fecf2c3ef1a..8fbc356de176c10b7d4503b6c6bbbe9954f95b77:/session.c diff --git a/session.c b/session.c index 9c4828ac..1e9e3228 100644 --- a/session.c +++ b/session.c @@ -9,7 +9,7 @@ * called by a name other than "ssh" or "Secure Shell". * * SSH2 support by Markus Friedl. - * Copyright (c) 2000 Markus Friedl. All rights reserved. + * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions @@ -33,7 +33,7 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.61 2001/03/16 19:06:30 markus Exp $"); +RCSID("$OpenBSD: session.c,v 1.100 2001/08/16 19:18:34 jakob Exp $"); #include "ssh.h" #include "ssh1.h" @@ -46,7 +46,6 @@ RCSID("$OpenBSD: session.c,v 1.61 2001/03/16 19:06:30 markus Exp $"); #include "uidswap.h" #include "compat.h" #include "channels.h" -#include "nchan.h" #include "bufaux.h" #include "auth.h" #include "auth-options.h" @@ -100,8 +99,8 @@ typedef struct Session Session; struct Session { int used; int self; - int extended; - struct passwd *pw; + struct passwd *pw; + Authctxt *authctxt; pid_t pid; /* tty */ char *term; @@ -116,18 +115,29 @@ struct Session { int single_connection; /* proto 2 */ int chanid; + int is_subsystem; }; /* func */ Session *session_new(void); -void session_set_fds(Session *s, int fdin, int fdout, int fderr); -void session_pty_cleanup(Session *s); -void session_proctitle(Session *s); -void do_exec_pty(Session *s, const char *command, struct passwd * pw); -void do_exec_no_pty(Session *s, const char *command, struct passwd * pw); -void do_login(Session *s, const char *command); -void do_child(Session *s, const char *command); +void session_set_fds(Session *, int, int, int); +static void session_pty_cleanup(void *); +void session_proctitle(Session *); +int session_setup_x11fwd(Session *); +void do_exec_pty(Session *, const char *); +void do_exec_no_pty(Session *, const char *); +void do_exec(Session *, const char *); +void do_login(Session *, const char *); +void do_child(Session *, const char *); +void do_motd(void); +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 *); /* import */ extern ServerOptions options; @@ -135,14 +145,11 @@ extern char *__progname; extern int log_stderr; extern int debug_flag; extern u_int utmp_len; - extern int startup_pipe; - -/* Local Xauthority file. */ -static char *xauthfile; +extern void destroy_sensitive_data(void); /* original command from peer. */ -char *original_command = NULL; +const char *original_command = NULL; /* data */ #define MAX_SESSIONS 10 @@ -157,46 +164,50 @@ char *aixloginmsg; static login_cap_t *lc; #endif -/* - * Remove local Xauthority file. - */ void -xauthfile_cleanup_proc(void *ignore) +do_authenticated(Authctxt *authctxt) { - debug("xauthfile_cleanup_proc called"); - - if (xauthfile != NULL) { - char *p; - unlink(xauthfile); - p = strrchr(xauthfile, '/'); - if (p != NULL) { - *p = '\0'; - rmdir(xauthfile); - } - xfree(xauthfile); - xauthfile = NULL; + /* + * Cancel the alarm we set to limit the time taken for + * authentication. + */ + alarm(0); + if (startup_pipe != -1) { + close(startup_pipe); + startup_pipe = -1; } -} - -/* - * Function to perform cleanup if we get aborted abnormally (e.g., due to a - * dropped connection). - */ -void -pty_cleanup_proc(void *session) -{ - Session *s=session; - if (s == NULL) - fatal("pty_cleanup_proc: no session"); - debug("pty_cleanup_proc: %s", s->tty); - - if (s->pid != 0) { - /* Record that the user has logged out. */ - record_logout(s->pid, s->tty); +#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; + } +#ifdef BSD_AUTH + if (auth_approval(NULL, lc, authctxt->pw->pw_name, "ssh") <= 0) { + packet_disconnect("Approval failure for %s", + authctxt->pw->pw_name); } +#endif +#endif + /* setup the channel layer */ + if (!no_port_forwarding_flag && options.allow_tcp_forwarding) + channel_permit_all_opens(); - /* Release the pseudo-tty. */ - pty_release(s->tty); + if (compat20) + do_authenticated2(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); +#endif } /* @@ -205,48 +216,25 @@ pty_cleanup_proc(void *session) * terminals are allocated, X11, TCP/IP, and authentication agent forwardings * are requested, etc. */ -void -do_authenticated(struct passwd * pw) +static void +do_authenticated1(Authctxt *authctxt) { Session *s; - int type, fd; - int compression_level = 0, enable_compression_after_reply = 0; - int have_pty = 0; char *command; - int n_bytes; - int plen; + int success, type, plen, screen_flag; + int compression_level = 0, enable_compression_after_reply = 0; u_int proto_len, data_len, dlen; - int screen_flag; - - /* - * 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 (!no_port_forwarding_flag && options.allow_tcp_forwarding) - channel_permit_all_opens(); s = session_new(); - s->pw = pw; - -#if defined(HAVE_LOGIN_CAP) && defined(HAVE_PW_CLASS_IN_PASSWD) - if ((lc = login_getclass(pw->pw_class)) == NULL) { - error("unable to get login class"); - return; - } -#endif + s->authctxt = authctxt; + s->pw = authctxt->pw; /* * We stay in this loop until the client requests to execute a shell * or a command. */ for (;;) { - int success = 0; + success = 0; /* Get a packet from the client. */ type = packet_read(&plen); @@ -267,70 +255,10 @@ do_authenticated(struct passwd * pw) break; case SSH_CMSG_REQUEST_PTY: - if (no_pty_flag) { - debug("Allocating a pty not permitted for this authentication."); - break; - } - if (have_pty) - packet_disconnect("Protocol error: you already have a pty."); - - debug("Allocating pty."); - - /* Allocate a pty and open it. */ - if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, - sizeof(s->tty))) { - error("Failed to allocate pty."); - break; - } - fatal_add_cleanup(pty_cleanup_proc, (void *)s); - pty_setowner(pw, s->tty); - - /* Get TERM from the packet. Note that the value may be of arbitrary length. */ - s->term = packet_get_string(&dlen); - packet_integrity_check(dlen, strlen(s->term), type); - /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */ - /* Remaining bytes */ - n_bytes = plen - (4 + dlen + 4 * 4); - - if (strcmp(s->term, "") == 0) { - xfree(s->term); - s->term = NULL; - } - /* Get window size from the packet. */ - s->row = packet_get_int(); - s->col = packet_get_int(); - s->xpixel = packet_get_int(); - s->ypixel = packet_get_int(); - pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); - - /* Get tty modes from the packet. */ - tty_parse_modes(s->ttyfd, &n_bytes); - packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type); - - session_proctitle(s); - - /* Indicate that we now have a pty. */ - success = 1; - have_pty = 1; + success = session_pty_req(s); break; case SSH_CMSG_X11_REQUEST_FORWARDING: - if (!options.x11_forwarding) { - packet_send_debug("X11 forwarding disabled in server configuration file."); - break; - } - if (!options.xauth_location) { - packet_send_debug("No xauth program; cannot forward with spoofing."); - break; - } - if (no_x11_forwarding_flag) { - packet_send_debug("X11 forwarding not permitted for this authentication."); - break; - } - debug("Received request for X11 forwarding with auth spoofing."); - if (s->display != NULL) - packet_disconnect("Protocol error: X11 display already set."); - s->auth_proto = packet_get_string(&proto_len); s->auth_data = packet_get_string(&data_len); @@ -342,39 +270,18 @@ do_authenticated(struct passwd * pw) if (!screen_flag) debug2("Buggy client: " "X11 screen flag missing"); - packet_integrity_check(plen, - 4 + proto_len + 4 + data_len + 4, type); s->screen = packet_get_int(); } else { - packet_integrity_check(plen, - 4 + proto_len + 4 + data_len, type); s->screen = 0; } - s->display = x11_create_display_inet(s->screen, options.x11_display_offset); - - if (s->display == NULL) - break; - - /* Setup to always have a local .Xauthority. */ - xauthfile = xmalloc(MAXPATHLEN); - strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); - temporarily_use_uid(pw->pw_uid); - if (mkdtemp(xauthfile) == NULL) { - restore_uid(); - error("private X11 dir: mkdtemp %s failed: %s", - xauthfile, strerror(errno)); - xfree(xauthfile); - xauthfile = NULL; - /* XXXX remove listening channels */ - break; + packet_done(); + success = session_setup_x11fwd(s); + if (!success) { + xfree(s->auth_proto); + xfree(s->auth_data); + s->auth_proto = NULL; + s->auth_data = NULL; } - strlcat(xauthfile, "/cookies", MAXPATHLEN); - fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); - if (fd >= 0) - close(fd); - restore_uid(); - fatal_add_cleanup(xauthfile_cleanup_proc, NULL); - success = 1; break; case SSH_CMSG_AGENT_REQUEST_FORWARDING: @@ -383,7 +290,7 @@ do_authenticated(struct passwd * pw) break; } debug("Received authentication agent forwarding request."); - success = auth_input_request_forwarding(pw); + success = auth_input_request_forwarding(s->pw); break; case SSH_CMSG_PORT_FORWARD_REQUEST: @@ -396,7 +303,7 @@ do_authenticated(struct passwd * pw) break; } debug("Received TCP/IP port forwarding request."); - channel_input_port_forward_request(pw->pw_uid == 0, options.gateway_ports); + channel_input_port_forward_request(s->pw->pw_uid == 0, options.gateway_ports); success = 1; break; @@ -404,32 +311,71 @@ do_authenticated(struct passwd * pw) 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: if (type == SSH_CMSG_EXEC_CMD) { command = packet_get_string(&dlen); debug("Exec command '%.500s'", command); - packet_integrity_check(plen, 4 + dlen, type); + do_exec(s, command); + xfree(command); } else { - command = NULL; - packet_integrity_check(plen, 0, type); - } - if (forced_command != NULL) { - original_command = command; - command = forced_command; - debug("Forced command '%.500s'", forced_command); + do_exec(s, NULL); } - if (have_pty) - do_exec_pty(s, command, pw); - else - do_exec_no_pty(s, command, pw); - - if (command != NULL) - xfree(command); - /* Cleanup user's local Xauthority file. */ - if (xauthfile) - xauthfile_cleanup_proc(NULL); + packet_done(); + session_close(s); return; default: @@ -457,7 +403,7 @@ do_authenticated(struct passwd * pw) * setting up file descriptors and such. */ void -do_exec_no_pty(Session *s, const char *command, struct passwd * pw) +do_exec_no_pty(Session *s, const char *command) { int pid; @@ -481,7 +427,8 @@ do_exec_no_pty(Session *s, const char *command, struct passwd * pw) session_proctitle(s); #if defined(USE_PAM) - do_pam_setcred(); + do_pam_session(s->pw->pw_name, NULL); + do_pam_setcred(1); #endif /* USE_PAM */ /* Fork the child. */ @@ -489,8 +436,6 @@ do_exec_no_pty(Session *s, const char *command, struct passwd * pw) /* Child. Reinitialize the log since the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); - signal(SIGPIPE, SIG_DFL); - /* * Create a new session and process group since the 4.4BSD * setlogin() affects the entire process group. @@ -555,11 +500,11 @@ do_exec_no_pty(Session *s, const char *command, struct passwd * pw) close(perr[1]); if (compat20) { - session_set_fds(s, pin[1], pout[0], s->extended ? perr[0] : -1); + session_set_fds(s, pin[1], pout[0], s->is_subsystem ? -1 : perr[0]); } else { /* Enter the interactive session. */ server_loop(pid, pin[1], pout[0], perr[0]); - /* server_loop has closed pin[1], pout[1], and perr[1]. */ + /* server_loop has closed pin[1], pout[0], and perr[0]. */ } #else /* USE_PIPES */ /* We are the parent. Close the child sides of the socket pairs. */ @@ -571,7 +516,7 @@ do_exec_no_pty(Session *s, const char *command, struct passwd * pw) * handle the case that fdin and fdout are the same. */ if (compat20) { - session_set_fds(s, inout[1], inout[1], s->extended ? err[1] : -1); + session_set_fds(s, inout[1], inout[1], s->is_subsystem ? -1 : err[1]); } else { server_loop(pid, inout[1], inout[1], err[1]); /* server_loop has closed inout[1] and err[1]. */ @@ -586,7 +531,7 @@ do_exec_no_pty(Session *s, const char *command, struct passwd * pw) * lastlog, and other such operations. */ void -do_exec_pty(Session *s, const char *command, struct passwd * pw) +do_exec_pty(Session *s, const char *command) { int fdout, ptyfd, ttyfd, ptymaster; pid_t pid; @@ -597,17 +542,15 @@ do_exec_pty(Session *s, const char *command, struct passwd * pw) ttyfd = s->ttyfd; #if defined(USE_PAM) - do_pam_session(pw->pw_name, s->tty); - do_pam_setcred(); + do_pam_session(s->pw->pw_name, s->tty); + do_pam_setcred(1); #endif /* Fork the child. */ if ((pid = fork()) == 0) { + /* Child. Reinitialize the log because the pid has changed. */ log_init(__progname, options.log_level, options.log_facility, log_stderr); - - signal(SIGPIPE, SIG_DFL); - /* Close the master side of the pseudo tty. */ close(ptyfd); @@ -630,8 +573,14 @@ do_exec_pty(Session *s, const char *command, struct passwd * pw) close(ttyfd); /* record login, etc. similar to login(1) */ +#ifndef HAVE_OSF_SIA if (!(options.use_login && command == NULL)) do_login(s, command); +# ifdef LOGIN_NEEDS_UTMPX + else + do_pre_login(s); +# endif +#endif /* Do common processing for the child, such as execing the command. */ do_child(s, command); @@ -670,32 +619,66 @@ do_exec_pty(Session *s, const char *command, struct passwd * pw) } else { server_loop(pid, ptyfd, fdout, -1); /* server_loop _has_ closed ptyfd and fdout. */ - session_pty_cleanup(s); } } -const char * -get_remote_name_or_ip(void) +#ifdef LOGIN_NEEDS_UTMPX +void +do_pre_login(Session *s) { - static const char *remote = ""; - if (utmp_len > 0) - remote = get_canonical_hostname(options.reverse_mapping_check); - if (utmp_len == 0 || strlen(remote) > utmp_len) - remote = get_remote_ipaddr(); - return remote; + socklen_t fromlen; + struct sockaddr_storage from; + pid_t pid = getpid(); + + /* + * Get IP address of client. If the connection is not a socket, let + * the address be 0.0.0.0. + */ + memset(&from, 0, 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(); + } + } + + record_utmp_only(pid, s->tty, s->pw->pw_name, + get_remote_name_or_ip(utmp_len, options.reverse_mapping_check), + (struct sockaddr *)&from); +} +#endif + +/* + * This is called to fork and execute a command. If another command is + * to be forced, execute that instead. + */ +void +do_exec(Session *s, const char *command) +{ + if (forced_command) { + original_command = command; + command = forced_command; + debug("Forced command '%.900s'", command); + } + + if (s->ttyfd != -1) + do_exec_pty(s, command); + else + do_exec_no_pty(s, command); + + original_command = NULL; } /* administrative, login(1)-like work */ void do_login(Session *s, const char *command) { - FILE *f; char *time_string; - char buf[256]; char hostname[MAXHOSTNAMELEN]; socklen_t fromlen; struct sockaddr_storage from; - struct stat st; time_t last_login_time; struct passwd * pw = s->pw; pid_t pid = getpid(); @@ -715,13 +698,16 @@ do_login(Session *s, const char *command) } /* Get the time and hostname when the user last logged in. */ - hostname[0] = '\0'; - last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name, - hostname, sizeof(hostname)); + 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(), (struct sockaddr *)&from); + get_remote_name_or_ip(utmp_len, options.reverse_mapping_check), + (struct sockaddr *)&from); #ifdef USE_PAM /* @@ -734,15 +720,7 @@ do_login(Session *s, const char *command) } #endif - /* Done if .hushlogin exists or a command given. */ - if (command != NULL) - return; - snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); -#ifdef HAVE_LOGIN_CAP - if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) -#else - if (stat(buf, &st) >= 0) -#endif + if (check_quietlogin(s, command)) return; #ifdef USE_PAM @@ -754,7 +732,7 @@ do_login(Session *s, const char *command) printf("%s\n", aixloginmsg); #endif /* WITH_AIXAUTHENTICATE */ - if (last_login_time != 0) { + if (options.print_lastlog && last_login_time != 0) { time_string = ctime(&last_login_time); if (strchr(time_string, '\n')) *strchr(time_string, '\n') = 0; @@ -763,6 +741,19 @@ do_login(Session *s, const char *command) else printf("Last login: %s from %s\r\n", time_string, hostname); } + + do_motd(); +} + +/* + * Display the message of the day. + */ +void +do_motd(void) +{ + FILE *f; + char buf[256]; + if (options.print_motd) { #ifdef HAVE_LOGIN_CAP f = fopen(login_getcapstr(lc, "welcome", "/etc/motd", @@ -778,11 +769,36 @@ do_login(Session *s, const char *command) } } + +/* + * Check for quiet login, either .hushlogin or command given. + */ +int +check_quietlogin(Session *s, const char *command) +{ + char buf[256]; + struct passwd *pw = s->pw; + struct stat st; + + /* Return 1 if .hushlogin exists or a command given. */ + if (command != NULL) + return 1; + snprintf(buf, sizeof(buf), "%.200s/.hushlogin", pw->pw_dir); +#ifdef HAVE_LOGIN_CAP + if (login_getcapbool(lc, "hushlogin", 0) || stat(buf, &st) >= 0) + return 1; +#else + if (stat(buf, &st) >= 0) + return 1; +#endif + return 0; +} + /* * Sets the value of the given variable in the environment. If the variable * already exists, its value is overriden. */ -void +static void child_set_env(char ***envp, u_int *envsizep, const char *name, const char *value) { @@ -823,7 +839,7 @@ child_set_env(char ***envp, u_int *envsizep, const char *name, * Otherwise, it must consist of empty lines, comments (line starts with '#') * and assignments of the form name=value. No other forms are allowed. */ -void +static void read_environment_file(char ***env, u_int *envsize, const char *filename) { @@ -862,7 +878,7 @@ read_environment_file(char ***env, u_int *envsize, /* * Sets any environment variables which have been specified by PAM */ -void do_pam_environment(char ***env, int *envsize) +void do_pam_environment(char ***env, u_int *envsize) { char *equals, var_name[512], var_val[512]; char **pam_env; @@ -891,7 +907,7 @@ void do_pam_environment(char ***env, int *envsize) #endif /* USE_PAM */ #ifdef HAVE_CYGWIN -void copy_environment(char ***env, int *envsize) +void copy_environment(char ***env, u_int *envsize) { char *equals, var_name[512], var_val[512]; int i; @@ -1003,7 +1019,7 @@ void do_child(Session *s, const char *command) { const char *shell, *hostname = NULL, *cp = NULL; - struct passwd * pw = s->pw; + struct passwd *pw = s->pw; char buf[256]; char cmd[1024]; FILE *f = NULL; @@ -1012,7 +1028,7 @@ do_child(Session *s, const char *command) extern char **environ; struct stat st; char *argv[10]; - int do_xauth = s->auth_proto != NULL && s->auth_data != NULL; + int do_xauth; #ifdef WITH_IRIX_PROJECT prid_t projid; #endif /* WITH_IRIX_PROJECT */ @@ -1024,11 +1040,17 @@ do_child(Session *s, const char *command) #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(); + /* login(1) is only called if we execute the login shell */ if (options.use_login && command != NULL) options.use_login = 0; -#ifndef USE_PAM /* pam_nologin handles this */ +#if !defined(HAVE_OSF_SIA) if (!options.use_login) { # ifdef HAVE_LOGIN_CAP if (!login_getcapbool(lc, "ignorenologin", 0) && pw->pw_uid) @@ -1046,14 +1068,16 @@ do_child(Session *s, const char *command) exit(254); } } -#endif /* USE_PAM */ +#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, ttyname); + 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) { @@ -1069,13 +1093,6 @@ do_child(Session *s, const char *command) perror("unable to set user context"); exit(1); } -#ifdef BSD_AUTH - if (auth_approval(NULL, lc, pw->pw_name, "ssh") <= 0) { - error("approval failure for %s", pw->pw_name); - fprintf(stderr, "Approval failure"); - exit(1); - } -#endif # else /* HAVE_LOGIN_CAP */ #if defined(HAVE_GETLUID) && defined(HAVE_SETLUID) /* Sets login uid for accounting */ @@ -1095,6 +1112,15 @@ do_child(Session *s, const char *command) 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) { @@ -1134,10 +1160,12 @@ do_child(Session *s, const char *command) * other stuff is stored - a few applications * actually use this and die if it's not set */ - cp = xmalloc(22 + strlen(ttyname) + + 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, ttyname, 0,0); + 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)); @@ -1146,7 +1174,7 @@ do_child(Session *s, const char *command) #endif /* Permanently switch to the desired uid. */ - permanently_set_uid(pw->pw_uid); + permanently_set_uid(pw); # endif /* HAVE_LOGIN_CAP */ } #endif /* HAVE_OSF_SIA */ @@ -1170,10 +1198,10 @@ do_child(Session *s, const char *command) /* Try to get AFS tokens for the local cell. */ if (k_hasafs()) { char cell[64]; - + if (k_afs_cell_of_file(pw->pw_dir, cell, sizeof(cell)) == 0) krb_afslog(cell, 0); - + krb_afslog(0, 0); } #endif /* AFS */ @@ -1257,23 +1285,21 @@ do_child(Session *s, const char *command) child_set_env(&env, &envsize, "KRB5CCNAME", cp); read_environment_file(&env, &envsize, "/etc/environment"); #endif - #ifdef KRB4 - { - extern char *ticket; - - if (ticket) - child_set_env(&env, &envsize, "KRBTKFILE", ticket); - } -#endif /* 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) + child_set_env(&env, &envsize, "KRB5CCNAME", + s->authctxt->krb5_ticket_file); +#endif #ifdef USE_PAM /* Pull in any environment variables that may have been set by PAM. */ do_pam_environment(&env, &envsize); #endif /* USE_PAM */ - if (xauthfile) - child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); if (auth_get_socket_name() != NULL) child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, auth_get_socket_name()); @@ -1292,7 +1318,8 @@ do_child(Session *s, const char *command) } /* we have to stash the hostname before we close our socket. */ if (options.use_login) - hostname = get_remote_name_or_ip(); + 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 @@ -1349,24 +1376,25 @@ do_child(Session *s, const char *command) * in this order). */ if (!options.use_login) { - if (stat(_PATH_SSH_USER_RC, &st) >= 0) { + /* 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 %s\n", _PATH_BSHELL, - _PATH_SSH_USER_RC); - f = popen(_PATH_BSHELL " " _PATH_SSH_USER_RC, "w"); + 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", + 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) @@ -1418,6 +1446,10 @@ do_child(Session *s, const char *command) else cp = shell; } + + /* restore SIGPIPE for child */ + signal(SIGPIPE, SIG_DFL); + /* * If we have no command, execute the shell. In this case, the shell * name to be passed in argv[0] is preceded by '-' to indicate that @@ -1427,25 +1459,6 @@ do_child(Session *s, const char *command) if (!options.use_login) { char buf[256]; - /* - * Check for mail if we have a tty and it was enabled - * in server options. - */ - if (s->ttyfd != -1 && options.check_mail) { - char *mailbox; - struct stat mailstat; - - mailbox = getenv("MAIL"); - if (mailbox != NULL) { - if (stat(mailbox, &mailstat) != 0 || - mailstat.st_size == 0) - printf("No mail.\n"); - else if (mailstat.st_mtime < mailstat.st_atime) - printf("You have mail.\n"); - else - printf("You have new mail.\n"); - } - } /* Start the shell. Set initial character to '-'. */ buf[0] = '-'; strncpy(buf + 1, cp, sizeof(buf) - 1); @@ -1464,7 +1477,10 @@ do_child(Session *s, const char *command) /* Launch login(1). */ execl(LOGIN_PROGRAM, "login", "-h", hostname, - "-p", "-f", "--", pw->pw_name, NULL); +#ifdef LOGIN_NEEDS_TERM + s->term? s->term : "unknown", +#endif + "-p", "-f", "--", pw->pw_name, (char *)NULL); /* Login couldn't be executed, die. */ @@ -1494,26 +1510,18 @@ session_new(void) debug("session_new: init"); for(i = 0; i < MAX_SESSIONS; i++) { sessions[i].used = 0; - sessions[i].self = i; } did_init = 1; } for(i = 0; i < MAX_SESSIONS; i++) { Session *s = &sessions[i]; if (! s->used) { - s->pid = 0; - s->extended = 0; + memset(s, 0, sizeof(*s)); s->chanid = -1; s->ptyfd = -1; s->ttyfd = -1; - s->term = NULL; - s->pw = NULL; - s->display = NULL; - s->screen = 0; - s->auth_data = NULL; - s->auth_proto = NULL; s->used = 1; - s->pw = NULL; + s->self = i; debug("session_new: session %d", i); return s; } @@ -1521,7 +1529,7 @@ session_new(void) return NULL; } -void +static void session_dump(void) { int i; @@ -1537,7 +1545,7 @@ session_dump(void) } int -session_open(int chanid) +session_open(Authctxt *authctxt, int chanid) { Session *s = session_new(); debug("session_open: channel %d", chanid); @@ -1545,7 +1553,8 @@ session_open(int chanid) error("no more sessions"); return 0; } - s->pw = auth_get_user(); + s->authctxt = authctxt; + s->pw = authctxt->pw; if (s->pw == NULL) fatal("no user for session %d", s->self); debug("session_open: session %d: link with channel %d", s->self, chanid); @@ -1553,7 +1562,7 @@ session_open(int chanid) return 1; } -Session * +static Session * session_by_channel(int id) { int i; @@ -1569,7 +1578,7 @@ session_by_channel(int id) return NULL; } -Session * +static Session * session_by_pid(pid_t pid) { int i; @@ -1584,7 +1593,7 @@ session_by_pid(pid_t pid) return NULL; } -int +static int session_window_change_req(Session *s) { s->col = packet_get_int(); @@ -1596,56 +1605,72 @@ session_window_change_req(Session *s) return 1; } -int +static int session_pty_req(Session *s) { u_int len; - char *term_modes; /* encoded terminal modes */ + int n_bytes; - if (no_pty_flag) + if (no_pty_flag) { + debug("Allocating a pty not permitted for this authentication."); return 0; - if (s->ttyfd != -1) + } + if (s->ttyfd != -1) { + packet_disconnect("Protocol error: you already have a pty."); return 0; + } + s->term = packet_get_string(&len); - s->col = packet_get_int(); - s->row = packet_get_int(); + + if (compat20) { + s->col = packet_get_int(); + s->row = packet_get_int(); + } else { + s->row = packet_get_int(); + s->col = packet_get_int(); + } s->xpixel = packet_get_int(); s->ypixel = packet_get_int(); - term_modes = packet_get_string(&len); - packet_done(); if (strcmp(s->term, "") == 0) { xfree(s->term); s->term = NULL; } + /* Allocate a pty and open it. */ + debug("Allocating pty."); if (!pty_allocate(&s->ptyfd, &s->ttyfd, s->tty, sizeof(s->tty))) { - xfree(s->term); + if (s->term) + xfree(s->term); s->term = NULL; s->ptyfd = -1; s->ttyfd = -1; error("session_pty_req: session %d alloc failed", s->self); - xfree(term_modes); return 0; } debug("session_pty_req: session %d alloc %s", s->self, s->tty); + + /* for SSH1 the tty modes length is not given */ + if (!compat20) + 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(pty_cleanup_proc, (void *)s); + fatal_add_cleanup(session_pty_cleanup, (void *)s); pty_setowner(s->pw, s->tty); - /* Get window size from the packet. */ + + /* Set window size from the packet. */ pty_change_window_size(s->ptyfd, s->row, s->col, s->xpixel, s->ypixel); + packet_done(); session_proctitle(s); - - /* XXX parse and set terminal modes */ - xfree(term_modes); return 1; } -int +static int session_subsystem_req(Session *s) { u_int len; @@ -1659,7 +1684,8 @@ session_subsystem_req(Session *s) for (i = 0; i < options.num_subsystems; i++) { if(strcmp(subsys, options.subsystem_name[i]) == 0) { debug("subsystem: exec() %s", options.subsystem_command[i]); - do_exec_no_pty(s, options.subsystem_command[i], s->pw); + s->is_subsystem = 1; + do_exec_no_pty(s, options.subsystem_command[i]); success = 1; } } @@ -1671,26 +1697,10 @@ session_subsystem_req(Session *s) return success; } -int +static int session_x11_req(Session *s) { - int fd; - if (no_x11_forwarding_flag) { - debug("X11 forwarding disabled in user configuration file."); - return 0; - } - if (!options.x11_forwarding) { - debug("X11 forwarding disabled in server configuration file."); - return 0; - } - if (xauthfile != NULL) { - debug("X11 fwd already started."); - return 0; - } - - debug("Received request for X11 forwarding with auth spoofing."); - if (s->display != NULL) - packet_disconnect("Protocol error: X11 display already set."); + int success; s->single_connection = packet_get_char(); s->auth_proto = packet_get_string(NULL); @@ -1698,71 +1708,36 @@ session_x11_req(Session *s) s->screen = packet_get_int(); packet_done(); - s->display = x11_create_display_inet(s->screen, options.x11_display_offset); - if (s->display == NULL) { + success = session_setup_x11fwd(s); + if (!success) { xfree(s->auth_proto); xfree(s->auth_data); - return 0; + s->auth_proto = NULL; + s->auth_data = NULL; } - xauthfile = xmalloc(MAXPATHLEN); - strlcpy(xauthfile, "/tmp/ssh-XXXXXXXX", MAXPATHLEN); - temporarily_use_uid(s->pw->pw_uid); - if (mkdtemp(xauthfile) == NULL) { - restore_uid(); - error("private X11 dir: mkdtemp %s failed: %s", - xauthfile, strerror(errno)); - xfree(xauthfile); - xauthfile = NULL; - xfree(s->auth_proto); - xfree(s->auth_data); - /* XXXX remove listening channels */ - return 0; - } - strlcat(xauthfile, "/cookies", MAXPATHLEN); - fd = open(xauthfile, O_RDWR|O_CREAT|O_EXCL, 0600); - if (fd >= 0) - close(fd); - restore_uid(); - fatal_add_cleanup(xauthfile_cleanup_proc, s); - return 1; + return success; } -int +static int session_shell_req(Session *s) { - /* if forced_command == NULL, the shell is execed */ - char *shell = forced_command; packet_done(); - s->extended = 1; - if (s->ttyfd == -1) - do_exec_no_pty(s, shell, s->pw); - else - do_exec_pty(s, shell, s->pw); + do_exec(s, NULL); return 1; } -int +static int session_exec_req(Session *s) { u_int len; char *command = packet_get_string(&len); packet_done(); - if (forced_command) { - original_command = command; - command = forced_command; - debug("Forced command '%.500s'", forced_command); - } - s->extended = 1; - if (s->ttyfd == -1) - do_exec_no_pty(s, command, s->pw); - else - do_exec_pty(s, command, s->pw); - if (forced_command == NULL) - xfree(command); + do_exec(s, command); + xfree(command); return 1; } -int +static int session_auth_agent_req(Session *s) { static int called = 0; @@ -1803,8 +1778,8 @@ session_input_channel_req(int id, void *arg) s->self, id, rtype, reply); /* - * a session is in LARVAL state until a shell - * or programm is executed + * a session is in LARVAL state until a shell, a command + * or a subsystem is executed */ if (c->type == SSH_CHANNEL_LARVAL) { if (strcmp(rtype, "shell") == 0) { @@ -1851,19 +1826,27 @@ session_set_fds(Session *s, int fdin, int fdout, int fderr) 1); } -void -session_pty_cleanup(Session *s) +/* + * 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) { - if (s == NULL || s->ttyfd == -1) + Session *s = session; + + if (s == NULL) { + error("session_pty_cleanup: no session"); + return; + } + if (s->ttyfd == -1) return; debug("session_pty_cleanup: session %d release %s", s->self, s->tty); - /* Cancel the cleanup function. */ - fatal_remove_cleanup(pty_cleanup_proc, (void *)s); - /* Record that the user has logged out. */ - record_logout(s->pid, s->tty); + if (s->pid != 0) + record_logout(s->pid, s->tty); /* Release the pseudo-tty. */ pty_release(s->tty); @@ -1877,7 +1860,7 @@ session_pty_cleanup(Session *s) error("close(s->ptymaster): %s", strerror(errno)); } -void +static void session_exit_message(Session *s, int status) { Channel *c; @@ -1885,7 +1868,7 @@ session_exit_message(Session *s, int status) fatal("session_close: no session"); c = channel_lookup(s->chanid); if (c == NULL) - fatal("session_close: session %d: no channel %d", + 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); @@ -1926,10 +1909,14 @@ session_exit_message(Session *s, int status) s->chanid = -1; } -void -session_free(Session *s) +static void +session_close(Session *s) { - debug("session_free: session %d pid %d", s->self, s->pid); + debug("session_close: session %d pid %d", s->self, s->pid); + if (s->ttyfd != -1) { + fatal_remove_cleanup(session_pty_cleanup, (void *)s); + session_pty_cleanup(s); + } if (s->term) xfree(s->term); if (s->display) @@ -1939,13 +1926,6 @@ session_free(Session *s) if (s->auth_proto) xfree(s->auth_proto); s->used = 0; -} - -void -session_close(Session *s) -{ - session_pty_cleanup(s); - session_free(s); session_proctitle(s); } @@ -1954,7 +1934,7 @@ 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", s->pid); + debug("session_close_by_pid: no session for pid %d", pid); return; } if (s->chanid != -1) @@ -1962,6 +1942,22 @@ session_close_by_pid(pid_t pid, int status) session_close(s); } +int +session_have_children(void) +{ + int i; + + for(i = 0; i < MAX_SESSIONS; i++) { + Session *s = &sessions[i]; + if (s->used && s->pid != -1) { + debug("session_have_children: id %d pid %d", i, s->pid); + return 1; + } + } + debug("session_have_children: no more children"); + return 0; +} + /* * this is called when a channel dies before * the session 'child' itself dies @@ -1990,7 +1986,7 @@ session_close_by_channel(int id, void *arg) } } -char * +static char * session_tty_list(void) { static char buf[1024]; @@ -2018,27 +2014,43 @@ session_proctitle(Session *s) setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); } -void -do_authenticated2(Authctxt *authctxt) +int +session_setup_x11fwd(Session *s) { - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - if (startup_pipe != -1) { - close(startup_pipe); - startup_pipe = -1; + struct stat st; + + if (no_x11_forwarding_flag) { + packet_send_debug("X11 forwarding disabled in user configuration file."); + return 0; } - if (!no_port_forwarding_flag && options.allow_tcp_forwarding) - channel_permit_all_opens(); -#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 (!options.x11_forwarding) { + debug("X11 forwarding disabled in server configuration file."); + return 0; } -#endif - server_loop2(); - if (xauthfile) - xauthfile_cleanup_proc(NULL); + if (!options.xauth_location || + (stat(options.xauth_location, &st) == -1)) { + packet_send_debug("No xauth program; cannot forward with spoofing."); + return 0; + } + if (options.use_login) { + packet_send_debug("X11 forwarding disabled; " + "not compatible with UseLogin=yes."); + return 0; + } + if (s->display != NULL) { + debug("X11 display already set."); + return 0; + } + s->display = x11_create_display_inet(s->screen, options.x11_display_offset); + if (s->display == NULL) { + debug("x11_create_display_inet failed."); + return 0; + } + return 1; +} + +static void +do_authenticated2(Authctxt *authctxt) +{ + server_loop2(authctxt); }