=================================================================== RCS file: /cvsrepo/anoncvs/cvs/src/usr.bin/ssh/session.c,v retrieving revision 1.42 retrieving revision 1.42.2.7 diff -u -r1.42 -r1.42.2.7 --- src/usr.bin/ssh/session.c 2000/10/27 07:32:18 1.42 +++ src/usr.bin/ssh/session.c 2001/11/15 00:15:00 1.42.2.7 @@ -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 @@ -33,29 +33,30 @@ */ #include "includes.h" -RCSID("$OpenBSD: session.c,v 1.42 2000/10/27 07:32:18 markus Exp $"); +RCSID("$OpenBSD: session.c,v 1.42.2.7 2001/11/15 00:15:00 miod Exp $"); -#include "xmalloc.h" #include "ssh.h" -#include "pty.h" +#include "ssh1.h" +#include "ssh2.h" +#include "xmalloc.h" +#include "sshpty.h" #include "packet.h" #include "buffer.h" #include "mpaux.h" -#include "servconf.h" #include "uidswap.h" #include "compat.h" #include "channels.h" -#include "nchan.h" - #include "bufaux.h" -#include "ssh2.h" #include "auth.h" #include "auth-options.h" +#include "pathnames.h" +#include "log.h" +#include "servconf.h" +#include "sshlogin.h" +#include "serverloop.h" +#include "canohost.h" +#include "session.h" -#ifdef HAVE_LOGIN_CAP -#include -#endif - /* types */ #define TTYSZ 64 @@ -63,8 +64,8 @@ struct Session { int used; int self; - int extended; - struct passwd *pw; + struct passwd *pw; + Authctxt *authctxt; pid_t pid; /* tty */ char *term; @@ -79,37 +80,41 @@ 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 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 *); -void -do_child(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname); +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; extern char *__progname; extern int log_stderr; extern int debug_flag; -extern unsigned int utmp_len; - +extern u_int utmp_len; extern int startup_pipe; +extern void destroy_sensitive_data(void); -/* Local Xauthority file. */ -static char *xauthfile; - /* original command from peer. */ -char *original_command = NULL; +const char *original_command = NULL; /* data */ #define MAX_SESSIONS 10 @@ -119,46 +124,50 @@ 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); +#ifdef HAVE_LOGIN_CAP + 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 } /* @@ -167,54 +176,25 @@ * 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; - unsigned int proto_len, data_len, dlen; + int success, type, plen, screen_flag; + int compression_level = 0, enable_compression_after_reply = 0; + u_int proto_len, data_len, dlen; - /* - * Cancel the alarm we set to limit the time taken for - * authentication. - */ - alarm(0); - if (startup_pipe != -1) { - close(startup_pipe); - startup_pipe = -1; - } - - /* - * Inform the channel mechanism that we are the server side and that - * the client may request to connect to any port at all. (The user - * could do it anyway, and we wouldn\'t know what is permitted except - * by the client telling us, so we can equally well trust the client - * not to request anything bogus.) - */ - if (!no_port_forwarding_flag && options.allow_tcp_forwarding) - channel_permit_all_opens(); - s = session_new(); - s->pw = pw; + s->authctxt = authctxt; + s->pw = authctxt->pw; -#ifdef HAVE_LOGIN_CAP - if ((lc = login_getclass(pw->pw_class)) == NULL) { - error("unable to get login class"); - return; - } -#endif - /* * 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); @@ -235,103 +215,33 @@ 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); - packet_integrity_check(plen, 4 + proto_len + 4 + data_len + 4, type); - if (packet_get_protocol_flags() & SSH_PROTOFLAG_SCREEN_NUMBER) + screen_flag = packet_get_protocol_flags() & + SSH_PROTOFLAG_SCREEN_NUMBER; + debug2("SSH_PROTOFLAG_SCREEN_NUMBER: %d", screen_flag); + + if (packet_remaining() == 4) { + if (!screen_flag) + debug2("Buggy client: " + "X11 screen flag missing"); s->screen = packet_get_int(); - else + } else { 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; } - 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; + 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; + } break; case SSH_CMSG_AGENT_REQUEST_FORWARDING: @@ -340,7 +250,7 @@ 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: @@ -353,7 +263,7 @@ 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; @@ -361,36 +271,71 @@ 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: - /* Set interactive/non-interactive mode. */ - packet_set_interactive(have_pty || s->display != NULL, - options.keepalives); - 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); + do_exec(s, NULL); } - if (forced_command != NULL) { - original_command = command; - command = forced_command; - debug("Forced command '%.500s'", forced_command); - } - 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: @@ -418,7 +363,7 @@ * 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; @@ -491,12 +436,14 @@ #endif /* USE_PIPES */ /* Do processing for the child (exec command etc). */ - do_child(command, pw, NULL, s->display, s->auth_proto, s->auth_data, NULL); + do_child(s, command); /* NOTREACHED */ } if (pid < 0) packet_disconnect("fork failed: %.100s", strerror(errno)); s->pid = pid; + /* Set interactive/non-interactive mode. */ + packet_set_interactive(s->display != NULL); #ifdef USE_PIPES /* We are the parent. Close the child sides of the pipes. */ close(pin[0]); @@ -504,11 +451,11 @@ 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. */ @@ -520,7 +467,7 @@ * 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]. */ @@ -535,7 +482,7 @@ * 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; @@ -547,27 +494,23 @@ /* 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); - /* Close the master side of the pseudo tty. */ close(ptyfd); /* Make the pseudo tty our controlling tty. */ pty_make_controlling_tty(&ttyfd, s->tty); - /* Redirect stdin from the pseudo tty. */ - if (dup2(ttyfd, fileno(stdin)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); + /* Redirect stdin/stdout/stderr from the pseudo tty. */ + if (dup2(ttyfd, 0) < 0) + error("dup2 stdin: %s", strerror(errno)); + if (dup2(ttyfd, 1) < 0) + error("dup2 stdout: %s", strerror(errno)); + if (dup2(ttyfd, 2) < 0) + error("dup2 stderr: %s", strerror(errno)); - /* Redirect stdout to the pseudo tty. */ - if (dup2(ttyfd, fileno(stdout)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); - - /* Redirect stderr to the pseudo tty. */ - if (dup2(ttyfd, fileno(stderr)) < 0) - error("dup2 stdin failed: %.100s", strerror(errno)); - /* Close the extra descriptor for the pseudo tty. */ close(ttyfd); @@ -576,8 +519,7 @@ do_login(s, command); /* Do common processing for the child, such as execing the command. */ - do_child(command, pw, s->term, s->display, s->auth_proto, - s->auth_data, s->tty); + do_child(s, command); /* NOTREACHED */ } if (pid < 0) @@ -603,37 +545,45 @@ s->ptymaster = ptymaster; /* Enter interactive session. */ + packet_set_interactive(1); if (compat20) { session_set_fds(s, ptyfd, fdout, -1); } 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) +/* + * 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) { - static const char *remote = ""; - if (utmp_len > 0) - remote = get_canonical_hostname(); - if (utmp_len == 0 || strlen(remote) > utmp_len) - remote = get_remote_ipaddr(); - return remote; + 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(); @@ -653,25 +603,21 @@ } /* 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); - /* Done if .hushlogin exists or a command given. */ - if (command != NULL) + if (check_quietlogin(s, command)) 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 - return; - 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; @@ -680,6 +626,19 @@ 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", @@ -695,15 +654,40 @@ } } + /* + * 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 -child_set_env(char ***envp, unsigned int *envsizep, const char *name, +static void +child_set_env(char ***envp, u_int *envsizep, const char *name, const char *value) { - unsigned int i, namelen; + u_int i, namelen; char **env; /* @@ -740,8 +724,8 @@ * Otherwise, it must consist of empty lines, comments (line starts with '#') * and assignments of the form name=value. No other forms are allowed. */ -void -read_environment_file(char ***env, unsigned int *envsize, +static void +read_environment_file(char ***env, u_int *envsize, const char *filename) { FILE *f; @@ -781,20 +765,26 @@ * ids, and executing the command or shell. */ void -do_child(const char *command, struct passwd * pw, const char *term, - const char *display, const char *auth_proto, - const char *auth_data, const char *ttyname) +do_child(Session *s, const char *command) { const char *shell, *hostname = NULL, *cp = NULL; + struct passwd *pw = s->pw; char buf[256]; char cmd[1024]; FILE *f = NULL; - unsigned int envsize, i; + u_int envsize, i; char **env; extern char **environ; struct stat st; char *argv[10]; + int do_xauth; + 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; @@ -826,7 +816,6 @@ (LOGIN_SETALL & ~LOGIN_SETPATH)) < 0) { perror("unable to set user context"); exit(1); - } #else if (setlogin(pw->pw_name) < 0) @@ -843,7 +832,7 @@ endgrent(); /* Permanently switch to the desired uid. */ - permanently_set_uid(pw->pw_uid); + permanently_set_uid(pw); #endif } if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid) @@ -858,18 +847,6 @@ shell = login_getcapstr(lc, "shell", (char *)shell, (char *)shell); #endif -#ifdef AFS - /* 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 */ - /* Initialize the environment. */ envsize = 100; env = xmalloc(envsize * sizeof(char *)); @@ -916,27 +893,25 @@ get_remote_ipaddr(), get_remote_port(), get_local_port()); child_set_env(&env, &envsize, "SSH_CLIENT", buf); - if (ttyname) - child_set_env(&env, &envsize, "SSH_TTY", ttyname); - if (term) - child_set_env(&env, &envsize, "TERM", term); - if (display) - child_set_env(&env, &envsize, "DISPLAY", display); + if (s->ttyfd != -1) + child_set_env(&env, &envsize, "SSH_TTY", s->tty); + if (s->term) + child_set_env(&env, &envsize, "TERM", s->term); + if (s->display) + child_set_env(&env, &envsize, "DISPLAY", s->display); if (original_command) child_set_env(&env, &envsize, "SSH_ORIGINAL_COMMAND", original_command); - #ifdef KRB4 - { - extern char *ticket; - - if (ticket) - child_set_env(&env, &envsize, "KRBTKFILE", ticket); - } -#endif /* KRB4 */ - - if (xauthfile) - child_set_env(&env, &envsize, "XAUTHORITY", xauthfile); + 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 if (auth_get_socket_name() != NULL) child_set_env(&env, &envsize, SSH_AUTHSOCKET_ENV_NAME, auth_get_socket_name()); @@ -955,7 +930,8 @@ } /* 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 @@ -991,10 +967,28 @@ for (i = 3; i < 64; i++) close(i); + /* + * Must take new environment into use so that .ssh/rc, /etc/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()) { + 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 */ + /* 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)); + pw->pw_dir, strerror(errno)); #ifdef HAVE_LOGIN_CAP if (login_getcapbool(lc, "requirehome", 0)) exit(1); @@ -1002,69 +996,72 @@ } /* - * Must take new environment into use so that .ssh/rc, /etc/sshrc and - * xauth are run in the proper environment. - */ - environ = env; - - /* * Run $HOME/.ssh/rc, /etc/sshrc, or xauth (whichever is found first * in this order). */ if (!options.use_login) { - if (stat(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 /bin/sh %s\n", SSH_USER_RC); - - f = popen("/bin/sh " SSH_USER_RC, "w"); + fprintf(stderr, "Running %s\n", cmd); + f = popen(cmd, "w"); if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); + if (do_xauth) + fprintf(f, "%s %s\n", s->auth_proto, + s->auth_data); pclose(f); } else - fprintf(stderr, "Could not run %s\n", SSH_USER_RC); - } else if (stat(SSH_SYSTEM_RC, &st) >= 0) { + 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 /bin/sh %s\n", SSH_SYSTEM_RC); - - f = popen("/bin/sh " SSH_SYSTEM_RC, "w"); + fprintf(stderr, "Running %s %s\n", _PATH_BSHELL, + _PATH_SSH_SYSTEM_RC); + f = popen(_PATH_BSHELL " " _PATH_SSH_SYSTEM_RC, "w"); if (f) { - if (auth_proto != NULL && auth_data != NULL) - fprintf(f, "%s %s\n", auth_proto, auth_data); + if (do_xauth) + fprintf(f, "%s %s\n", s->auth_proto, + s->auth_data); pclose(f); } else - fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC); - } else if (options.xauth_location != NULL) { + 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 (auth_proto != NULL && auth_data != NULL) { - char *screen = strchr(display, ':'); - if (debug_flag) { + 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, - "Running %.100s add %.100s %.100s %.100s\n", - options.xauth_location, display, - auth_proto, auth_data); - if (screen != NULL) - fprintf(stderr, - "Adding %.*s/unix%s %s %s\n", - (int)(screen-display), display, - screen, auth_proto, auth_data); - } - snprintf(cmd, sizeof cmd, "%s -q -", - options.xauth_location); - f = popen(cmd, "w"); - if (f) { - fprintf(f, "add %s %s %s\n", display, - auth_proto, auth_data); - if (screen != NULL) - fprintf(f, "add %.*s/unix%s %s %s\n", - (int)(screen-display), display, - screen, auth_proto, auth_data); - pclose(f); - } else { - fprintf(stderr, "Could not run %s\n", - cmd); - } + "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, '/'); @@ -1073,6 +1070,10 @@ 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 @@ -1082,24 +1083,6 @@ if (!options.use_login) { char buf[256]; - /* - * Check for mail if we have a tty and it was enabled - * in server options. - */ - if (ttyname && 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); @@ -1118,7 +1101,7 @@ /* Launch login(1). */ execl("/usr/bin/login", "login", "-h", hostname, - "-p", "-f", "--", pw->pw_name, NULL); + "-p", "-f", "--", pw->pw_name, (char *)NULL); /* Login couldn't be executed, die. */ @@ -1148,26 +1131,18 @@ 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; } @@ -1175,7 +1150,7 @@ return NULL; } -void +static void session_dump(void) { int i; @@ -1191,7 +1166,7 @@ } int -session_open(int chanid) +session_open(Authctxt *authctxt, int chanid) { Session *s = session_new(); debug("session_open: channel %d", chanid); @@ -1199,15 +1174,16 @@ 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 %i", s->self); + 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 * +static Session * session_by_channel(int id) { int i; @@ -1223,7 +1199,7 @@ return NULL; } -Session * +static Session * session_by_pid(pid_t pid) { int i; @@ -1238,7 +1214,7 @@ return NULL; } -int +static int session_window_change_req(Session *s) { s->col = packet_get_int(); @@ -1250,176 +1226,167 @@ return 1; } -int +static int session_pty_req(Session *s) { - unsigned int len; - char *term_modes; /* encoded terminal modes */ + u_int len; + 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) { - unsigned int len; + struct stat st; + u_int len; int success = 0; - char *subsys = packet_get_string(&len); + char *cmd, *subsys = packet_get_string(&len); int i; packet_done(); log("subsystem request for %s", subsys); 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); + 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, + strerror(errno)); + break; + } + debug("subsystem: exec() %s", cmd); + s->is_subsystem = 1; + do_exec(s, cmd); success = 1; } } if (!success) - log("subsystem request for %s failed, subsystem not found", subsys); + log("subsystem request for %s failed, subsystem not found", + subsys); xfree(subsys); 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; - } + int success; - debug("Received request for X11 forwarding with auth spoofing."); - if (s->display != NULL) - packet_disconnect("Protocol error: X11 display already set."); - 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(); - 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) { - unsigned int len; + 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; } +static int +session_auth_agent_req(Session *s) +{ + static int called = 0; + packet_done(); + if (no_agent_forwarding_flag) { + debug("session_auth_agent_req: no_agent_forwarding_flag"); + return 0; + } + if (called) { + return 0; + } else { + called = 1; + return auth_input_request_forwarding(s->pw); + } +} + void session_input_channel_req(int id, void *arg) { - unsigned int len; + u_int len; int reply; int success = 0; char *rtype; @@ -1440,8 +1407,8 @@ 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) { @@ -1452,6 +1419,8 @@ 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); } @@ -1486,19 +1455,27 @@ 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 %i release %s", s->self, s->tty); + 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); @@ -1510,9 +1487,12 @@ */ if (close(s->ptymaster) < 0) error("close(s->ptymaster): %s", strerror(errno)); + + /* unlink pty from session */ + s->ttyfd = -1; } -void +static void session_exit_message(Session *s, int status) { Channel *c; @@ -1520,7 +1500,7 @@ 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); @@ -1557,10 +1537,14 @@ 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) @@ -1570,13 +1554,6 @@ 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); } @@ -1585,7 +1562,7 @@ { 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) @@ -1602,26 +1579,40 @@ { Session *s = session_by_channel(id); if (s == NULL) { - debug("session_close_by_channel: no session for channel %d", id); + debug("session_close_by_channel: no session for id %d", id); return; } - /* disconnect channel */ + debug("session_close_by_channel: channel %d child %d", id, 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); + session_pty_cleanup(s); + } + return; + } + /* detach by removing callback */ channel_cancel_cleanup(s->chanid); s->chanid = -1; + session_close(s); +} - debug("session_close_by_channel: channel %d kill %d", id, s->pid); - if (s->pid == 0) { - /* close session immediately */ - session_close(s); - } else { - /* notify child, delay session cleanup */ - if (kill(s->pid, (s->ttyfd == -1) ? SIGTERM : SIGHUP) < 0) - error("session_close_by_channel: kill %d: %s", - s->pid, strerror(errno)); +void +session_destroy_all(void) +{ + int i; + for(i = 0; i < MAX_SESSIONS; i++) { + Session *s = &sessions[i]; + if (s->used) + session_close(s); } } -char * +static char * session_tty_list(void) { static char buf[1024]; @@ -1649,28 +1640,43 @@ setproctitle("%s@%s", s->pw->pw_name, session_tty_list()); } -void -do_authenticated2(void) +int +session_setup_x11fwd(Session *s) { - struct passwd *pw; + struct stat st; - /* - * 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_x11_forwarding_flag) { + packet_send_debug("X11 forwarding disabled in user configuration file."); + return 0; } -#ifdef HAVE_LOGIN_CAP - pw = auth_get_user(); - if ((lc = login_getclass(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); }