- packet_disconnect(AUTH_FAIL_MSG, pw->pw_name);
- }
-#endif /* HAVE_LIBPAM */
-
- /* Send a message indicating that the authentication attempt failed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- }
-}
-
-/*
- * The user does not exist or access is denied,
- * but fake indication that authentication is needed.
- */
-void
-do_fake_authloop(char *user)
-{
- int attempt = 0;
-
- log("Faking authloop for illegal user %.200s from %.200s port %d",
- user,
- get_remote_ipaddr(),
- get_remote_port());
-
- /* Indicate that authentication is needed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
-
- /*
- * Keep reading packets, and always respond with a failure. This is
- * to avoid disclosing whether such a user really exists.
- */
- for (attempt = 1;; attempt++) {
- /* Read a packet. This will not return if the client disconnects. */
- int plen;
- int type = packet_read(&plen);
-#ifdef SKEY
- int dlen;
- char *password, *skeyinfo;
- /* Try to send a fake s/key challenge. */
- if (options.skey_authentication == 1 &&
- (skeyinfo = skey_fake_keyinfo(user)) != NULL) {
- if (type == SSH_CMSG_AUTH_TIS) {
- packet_start(SSH_SMSG_AUTH_TIS_CHALLENGE);
- packet_put_string(skeyinfo, strlen(skeyinfo));
- packet_send();
- packet_write_wait();
- continue;
- } else if (type == SSH_CMSG_AUTH_PASSWORD &&
- options.password_authentication &&
- (password = packet_get_string(&dlen)) != NULL &&
- dlen == 5 &&
- strncasecmp(password, "s/key", 5) == 0 ) {
- packet_send_debug(skeyinfo);
- }
- }
-#endif
- if (attempt > AUTH_FAIL_MAX)
- packet_disconnect(AUTH_FAIL_MSG, user);
-
- /*
- * Send failure. This should be indistinguishable from a
- * failed authentication.
- */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- }
- /* NOTREACHED */
- abort();
-}
-
-
-/*
- * Remove local Xauthority file.
- */
-static void
-xauthfile_cleanup_proc(void *ignore)
-{
- debug("xauthfile_cleanup_proc called");
-
- if (xauthfile != NULL) {
- unlink(xauthfile);
- xfree(xauthfile);
- xauthfile = NULL;
- }
-}
-
-/*
- * Prepares for an interactive session. This is called after the user has
- * been successfully authenticated. During this message exchange, pseudo
- * terminals are allocated, X11, TCP/IP, and authentication agent forwardings
- * are requested, etc.
- */
-void
-do_authenticated(struct passwd * pw)
-{
- int type;
- int compression_level = 0, enable_compression_after_reply = 0;
- int have_pty = 0, ptyfd = -1, ttyfd = -1, xauthfd = -1;
- int row, col, xpixel, ypixel, screen;
- char ttyname[64];
- char *command, *term = NULL, *display = NULL, *proto = NULL,
- *data = NULL;
- struct group *grp;
- gid_t tty_gid;
- mode_t tty_mode;
- int n_bytes;
-
- /*
- * Cancel the alarm we set to limit the time taken for
- * authentication.
- */
- alarm(0);
-
- /*
- * 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.)
- */
- channel_permit_all_opens();
-
- /*
- * We stay in this loop until the client requests to execute a shell
- * or a command.
- */
- while (1) {
- int plen, dlen;
-
- /* Get a packet from the client. */
- type = packet_read(&plen);
-
- /* Process the packet. */
- switch (type) {
- case SSH_CMSG_REQUEST_COMPRESSION:
- packet_integrity_check(plen, 4, type);
- compression_level = packet_get_int();
- if (compression_level < 1 || compression_level > 9) {
- packet_send_debug("Received illegal compression level %d.",
- compression_level);
- goto fail;
- }
- /* Enable compression after we have responded with SUCCESS. */
- enable_compression_after_reply = 1;
- break;
-
- case SSH_CMSG_REQUEST_PTY:
- if (no_pty_flag) {
- debug("Allocating a pty not permitted for this authentication.");
- goto fail;
- }
- if (have_pty)
- packet_disconnect("Protocol error: you already have a pty.");
-
- debug("Allocating pty.");
-
- /* Allocate a pty and open it. */
- if (!pty_allocate(&ptyfd, &ttyfd, ttyname,
- sizeof(ttyname))) {
- error("Failed to allocate pty.");
- goto fail;
- }
- /* Determine the group to make the owner of the tty. */
- grp = getgrnam("tty");
- if (grp) {
- tty_gid = grp->gr_gid;
- tty_mode = S_IRUSR | S_IWUSR | S_IWGRP;
- } else {
- tty_gid = pw->pw_gid;
- tty_mode = S_IRUSR | S_IWUSR | S_IWGRP | S_IWOTH;
- }
-
- /* Change ownership of the tty. */
- if (chown(ttyname, pw->pw_uid, tty_gid) < 0)
- fatal("chown(%.100s, %d, %d) failed: %.100s",
- ttyname, pw->pw_uid, tty_gid, strerror(errno));
- if (chmod(ttyname, tty_mode) < 0)
- fatal("chmod(%.100s, 0%o) failed: %.100s",
- ttyname, tty_mode, strerror(errno));
-
- /* Get TERM from the packet. Note that the value may be of arbitrary length. */
- term = packet_get_string(&dlen);
- packet_integrity_check(dlen, strlen(term), type);
- /* packet_integrity_check(plen, 4 + dlen + 4*4 + n_bytes, type); */
- /* Remaining bytes */
- n_bytes = plen - (4 + dlen + 4 * 4);
-
- if (strcmp(term, "") == 0)
- term = NULL;
-
- /* Get window size from the packet. */
- row = packet_get_int();
- col = packet_get_int();
- xpixel = packet_get_int();
- ypixel = packet_get_int();
- pty_change_window_size(ptyfd, row, col, xpixel, ypixel);
-
- /* Get tty modes from the packet. */
- tty_parse_modes(ttyfd, &n_bytes);
- packet_integrity_check(plen, 4 + dlen + 4 * 4 + n_bytes, type);
-
- /* Indicate that we now have a pty. */
- have_pty = 1;
-
-#ifdef HAVE_LIBPAM
- /* do the pam_open_session since we have the pty */
- do_pam_session(pw->pw_name,ttyname);
-#endif /* HAVE_LIBPAM */
-
- break;
-
- case SSH_CMSG_X11_REQUEST_FORWARDING:
- if (!options.x11_forwarding) {
- packet_send_debug("X11 forwarding disabled in server configuration file.");
- goto fail;
- }
-#ifdef XAUTH_PATH
- if (no_x11_forwarding_flag) {
- packet_send_debug("X11 forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received request for X11 forwarding with auth spoofing.");
- if (display)
- packet_disconnect("Protocol error: X11 display already set.");
- {
- int proto_len, data_len;
- proto = packet_get_string(&proto_len);
- 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 = packet_get_int();
- else
- screen = 0;
- display = x11_create_display_inet(screen, options.x11_display_offset);
- if (!display)
- goto fail;
-
- /* Setup to always have a local .Xauthority. */
- xauthfile = xmalloc(MAXPATHLEN);
- snprintf(xauthfile, MAXPATHLEN, "/tmp/XauthXXXXXX");
-
- if ((xauthfd = mkstemp(xauthfile)) != -1) {
- fchown(xauthfd, pw->pw_uid, pw->pw_gid);
- close(xauthfd);
- fatal_add_cleanup(xauthfile_cleanup_proc, NULL);
- } else {
- xfree(xauthfile);
- xauthfile = NULL;
- }
- break;
-#else /* XAUTH_PATH */
- packet_send_debug("No xauth program; cannot forward with spoofing.");
- goto fail;
-#endif /* XAUTH_PATH */
-
- case SSH_CMSG_AGENT_REQUEST_FORWARDING:
- if (no_agent_forwarding_flag) {
- debug("Authentication agent forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received authentication agent forwarding request.");
- auth_input_request_forwarding(pw);
- break;
-
- case SSH_CMSG_PORT_FORWARD_REQUEST:
- if (no_port_forwarding_flag) {
- debug("Port forwarding not permitted for this authentication.");
- goto fail;
- }
- debug("Received TCP/IP port forwarding request.");
- channel_input_port_forward_request(pw->pw_uid == 0);
- break;
-
- case SSH_CMSG_MAX_PACKET_SIZE:
- if (packet_set_maxsize(packet_get_int()) < 0)
- goto fail;
- break;
-
- case SSH_CMSG_EXEC_SHELL:
- /* Set interactive/non-interactive mode. */
- packet_set_interactive(have_pty || display != NULL,
- options.keepalives);
-
- if (forced_command != NULL)
- goto do_forced_command;
- debug("Forking shell.");
- packet_integrity_check(plen, 0, type);
- if (have_pty)
- do_exec_pty(NULL, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(NULL, pw, display, proto, data);
- return;
-
- case SSH_CMSG_EXEC_CMD:
- /* Set interactive/non-interactive mode. */
- packet_set_interactive(have_pty || display != NULL,
- options.keepalives);
-
- if (forced_command != NULL)
- goto do_forced_command;
- /* Get command from the packet. */
- {
- int dlen;
- command = packet_get_string(&dlen);
- debug("Executing command '%.500s'", command);
- packet_integrity_check(plen, 4 + dlen, type);
- }
- if (have_pty)
- do_exec_pty(command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(command, pw, display, proto, data);
- xfree(command);
- return;
-
- default:
- /*
- * Any unknown messages in this phase are ignored,
- * and a failure message is returned.
- */
- log("Unknown packet type received after authentication: %d", type);
- goto fail;
- }
-
- /* The request was successfully processed. */
- packet_start(SSH_SMSG_SUCCESS);
- packet_send();
- packet_write_wait();
-
- /* Enable compression now that we have replied if appropriate. */
- if (enable_compression_after_reply) {
- enable_compression_after_reply = 0;
- packet_start_compression(compression_level);
- }
- continue;
-
-fail:
- /* The request failed. */
- packet_start(SSH_SMSG_FAILURE);
- packet_send();
- packet_write_wait();
- continue;
-
-do_forced_command:
- /*
- * There is a forced command specified for this login.
- * Execute it.
- */
- debug("Executing forced command: %.900s", forced_command);
- if (have_pty)
- do_exec_pty(forced_command, ptyfd, ttyfd, ttyname, pw, term, display, proto, data);
- else
- do_exec_no_pty(forced_command, pw, display, proto, data);
- return;
- }
-}
-
-/*
- * This is called to fork and execute a command when we have no tty. This
- * will call do_child from the child, and server_loop from the parent after
- * setting up file descriptors and such.
- */
-void
-do_exec_no_pty(const char *command, struct passwd * pw,
- const char *display, const char *auth_proto,
- const char *auth_data)
-{
- int pid;
-
-#ifdef USE_PIPES
- int pin[2], pout[2], perr[2];
- /* Allocate pipes for communicating with the program. */
- if (pipe(pin) < 0 || pipe(pout) < 0 || pipe(perr) < 0)
- packet_disconnect("Could not create pipes: %.100s",
- strerror(errno));
-#else /* USE_PIPES */
- int inout[2], err[2];
- /* Uses socket pairs to communicate with the program. */
- if (socketpair(AF_UNIX, SOCK_STREAM, 0, inout) < 0 ||
- socketpair(AF_UNIX, SOCK_STREAM, 0, err) < 0)
- packet_disconnect("Could not create socket pairs: %.100s",
- strerror(errno));
-#endif /* USE_PIPES */
-
- setproctitle("%s@notty", pw->pw_name);
-
- /* Fork the child. */
- if ((pid = fork()) == 0) {
- /* Child. Reinitialize the log since the pid has changed. */
- log_init(av0, options.log_level, options.log_facility, log_stderr);
-
- /*
- * Create a new session and process group since the 4.4BSD
- * setlogin() affects the entire process group.
- */
- if (setsid() < 0)
- error("setsid failed: %.100s", strerror(errno));
-
-#ifdef USE_PIPES
- /*
- * Redirect stdin. We close the parent side of the socket
- * pair, and make the child side the standard input.
- */
- close(pin[1]);
- if (dup2(pin[0], 0) < 0)
- perror("dup2 stdin");
- close(pin[0]);
-
- /* Redirect stdout. */
- close(pout[0]);
- if (dup2(pout[1], 1) < 0)
- perror("dup2 stdout");
- close(pout[1]);
-
- /* Redirect stderr. */
- close(perr[0]);
- if (dup2(perr[1], 2) < 0)
- perror("dup2 stderr");
- close(perr[1]);
-#else /* USE_PIPES */
- /*
- * Redirect stdin, stdout, and stderr. Stdin and stdout will
- * use the same socket, as some programs (particularly rdist)
- * seem to depend on it.
- */
- close(inout[1]);
- close(err[1]);
- if (dup2(inout[0], 0) < 0) /* stdin */
- perror("dup2 stdin");
- if (dup2(inout[0], 1) < 0) /* stdout. Note: same socket as stdin. */
- perror("dup2 stdout");
- if (dup2(err[0], 2) < 0) /* stderr */
- perror("dup2 stderr");
-#endif /* USE_PIPES */
-
- /* Do processing for the child (exec command etc). */
- do_child(command, pw, NULL, display, auth_proto, auth_data, NULL);
- /* NOTREACHED */
- }
- if (pid < 0)
- packet_disconnect("fork failed: %.100s", strerror(errno));
-#ifdef USE_PIPES
- /* We are the parent. Close the child sides of the pipes. */
- close(pin[0]);
- close(pout[1]);
- close(perr[1]);
-
- /* Enter the interactive session. */
- server_loop(pid, pin[1], pout[0], perr[0]);
- /* server_loop has closed pin[1], pout[1], and perr[1]. */
-#else /* USE_PIPES */
- /* We are the parent. Close the child sides of the socket pairs. */
- close(inout[0]);
- close(err[0]);
-
- /*
- * Enter the interactive session. Note: server_loop must be able to
- * handle the case that fdin and fdout are the same.
- */
- server_loop(pid, inout[1], inout[1], err[1]);
- /* server_loop has closed inout[1] and err[1]. */
-#endif /* USE_PIPES */
-}
-
-struct pty_cleanup_context {
- const char *ttyname;
- int pid;
-};
-
-/*
- * Function to perform cleanup if we get aborted abnormally (e.g., due to a
- * dropped connection).
- */
-void
-pty_cleanup_proc(void *context)
-{
- struct pty_cleanup_context *cu = context;
-
- debug("pty_cleanup_proc called");
-
- /* Record that the user has logged out. */
- record_logout(cu->pid, cu->ttyname);
-
- /* Release the pseudo-tty. */
- pty_release(cu->ttyname);
-}
-
-/*
- * This is called to fork and execute a command when we have a tty. This
- * will call do_child from the child, and server_loop from the parent after
- * setting up file descriptors, controlling tty, updating wtmp, utmp,
- * lastlog, and other such operations.
- */
-void
-do_exec_pty(const char *command, int ptyfd, int ttyfd,
- const char *ttyname, struct passwd * pw, const char *term,
- const char *display, const char *auth_proto,
- const char *auth_data)
-{
- int pid, fdout;
- const char *hostname;
- time_t last_login_time;
- char buf[100], *time_string;
- FILE *f;
- char line[256];
- struct stat st;
- int quiet_login;
- struct sockaddr_in from;
- int fromlen;
- struct pty_cleanup_context cleanup_context;
-
- /* Get remote host name. */
- hostname = get_canonical_hostname();
-
- /*
- * Get the time when the user last logged in. Buf will be set to
- * contain the hostname the last login was from.
- */
- if (!options.use_login) {
- last_login_time = get_last_login_time(pw->pw_uid, pw->pw_name,
- buf, sizeof(buf));
- }
- setproctitle("%s@%s", pw->pw_name, strrchr(ttyname, '/') + 1);
-
- /* Fork the child. */
- if ((pid = fork()) == 0) {
- pid = getpid();
-
- /* Child. Reinitialize the log because the pid has
- changed. */
- log_init(av0, 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, ttyname);
-
- /* Redirect stdin from the pseudo tty. */
- if (dup2(ttyfd, fileno(stdin)) < 0)
- error("dup2 stdin failed: %.100s", 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);
-
- /*
- * Get IP address of client. This is needed because we want
- * to record where the user logged in from. If the
- * connection is not a socket, let the ip address be 0.0.0.0.
- */
- memset(&from, 0, sizeof(from));
- if (packet_get_connection_in() == packet_get_connection_out()) {
- fromlen = sizeof(from);
- if (getpeername(packet_get_connection_in(),
- (struct sockaddr *) & from, &fromlen) < 0) {
- debug("getpeername: %.100s", strerror(errno));
- fatal_cleanup();
- }
- }
- /* Record that there was a login on that terminal. */
- record_login(pid, ttyname, pw->pw_name, pw->pw_uid, hostname,
- &from);
-
- /* Check if .hushlogin exists. */
- snprintf(line, sizeof line, "%.200s/.hushlogin", pw->pw_dir);
- quiet_login = stat(line, &st) >= 0;
-
-#ifdef HAVE_LIBPAM
- /* output the results of the pamconv() */
- if (!quiet_login && pamconv_msg != NULL)
- fprintf(stderr, pamconv_msg);
-#endif
-
- /*
- * If the user has logged in before, display the time of last
- * login. However, don't display anything extra if a command
- * has been specified (so that ssh can be used to execute
- * commands on a remote machine without users knowing they
- * are going to another machine). Login(1) will do this for
- * us as well, so check if login(1) is used
- */
- if (command == NULL && last_login_time != 0 && !quiet_login &&
- !options.use_login) {
- /* Convert the date to a string. */
- time_string = ctime(&last_login_time);
- /* Remove the trailing newline. */
- if (strchr(time_string, '\n'))
- *strchr(time_string, '\n') = 0;
- /* Display the last login time. Host if displayed
- if known. */
- if (strcmp(buf, "") == 0)
- printf("Last login: %s\r\n", time_string);
- else
- printf("Last login: %s from %s\r\n", time_string, buf);
- }
- /*
- * Print /etc/motd unless a command was specified or printing
- * it was disabled in server options or login(1) will be
- * used. Note that some machines appear to print it in
- * /etc/profile or similar.
- */
- if (command == NULL && options.print_motd && !quiet_login &&
- !options.use_login) {
- /* Print /etc/motd if it exists. */
- f = fopen("/etc/motd", "r");
- if (f) {
- while (fgets(line, sizeof(line), f))
- fputs(line, stdout);
- fclose(f);
- }
- }
- /* Do common processing for the child, such as execing the command. */
- do_child(command, pw, term, display, auth_proto, auth_data, ttyname);
- /* NOTREACHED */
- }
- if (pid < 0)
- packet_disconnect("fork failed: %.100s", strerror(errno));
- /* Parent. Close the slave side of the pseudo tty. */
- close(ttyfd);
-
- /*
- * Create another descriptor of the pty master side for use as the
- * standard input. We could use the original descriptor, but this
- * simplifies code in server_loop. The descriptor is bidirectional.
- */
- fdout = dup(ptyfd);
- if (fdout < 0)
- packet_disconnect("dup failed: %.100s", strerror(errno));
-
- /*
- * Add a cleanup function to clear the utmp entry and record logout
- * time in case we call fatal() (e.g., the connection gets closed).
- */
- cleanup_context.pid = pid;
- cleanup_context.ttyname = ttyname;
- fatal_add_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
-
- /* Enter interactive session. */
- server_loop(pid, ptyfd, fdout, -1);
- /* server_loop has not closed ptyfd and fdout. */
-
- /* Cancel the cleanup function. */
- fatal_remove_cleanup(pty_cleanup_proc, (void *) &cleanup_context);
-
- /* Record that the user has logged out. */
- record_logout(pid, ttyname);
-
- /* Release the pseudo-tty. */
- pty_release(ttyname);
-
- /*
- * Close the server side of the socket pairs. We must do this after
- * the pty cleanup, so that another process doesn't get this pty
- * while we're still cleaning up.
- */
- close(ptyfd);
- close(fdout);
-}
-
-/*
- * 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,
- const char *value)
-{
- unsigned int i, namelen;
- char **env;
-
- /*
- * Find the slot where the value should be stored. If the variable
- * already exists, we reuse the slot; otherwise we append a new slot
- * at the end of the array, expanding if necessary.
- */
- env = *envp;
- namelen = strlen(name);
- for (i = 0; env[i]; i++)
- if (strncmp(env[i], name, namelen) == 0 && env[i][namelen] == '=')
- break;
- if (env[i]) {
- /* Reuse the slot. */
- xfree(env[i]);
- } else {
- /* New variable. Expand if necessary. */
- if (i >= (*envsizep) - 1) {
- (*envsizep) += 50;
- env = (*envp) = xrealloc(env, (*envsizep) * sizeof(char *));
- }
- /* Need to set the NULL pointer at end of array beyond the new slot. */
- env[i + 1] = NULL;
- }
-
- /* Allocate space and format the variable in the appropriate slot. */
- env[i] = xmalloc(strlen(name) + 1 + strlen(value) + 1);
- snprintf(env[i], strlen(name) + 1 + strlen(value) + 1, "%s=%s", name, value);
-}
-
-/*
- * Reads environment variables from the given file and adds/overrides them
- * into the environment. If the file does not exist, this does nothing.
- * 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,
- const char *filename)
-{
- FILE *f;
- char buf[4096];
- char *cp, *value;
-
- f = fopen(filename, "r");
- if (!f)
- return;
-
- while (fgets(buf, sizeof(buf), f)) {
- for (cp = buf; *cp == ' ' || *cp == '\t'; cp++)
- ;
- if (!*cp || *cp == '#' || *cp == '\n')
- continue;
- if (strchr(cp, '\n'))
- *strchr(cp, '\n') = '\0';
- value = strchr(cp, '=');
- if (value == NULL) {
- fprintf(stderr, "Bad line in %.100s: %.200s\n", filename, buf);
- continue;
- }
- /* Replace the equals sign by nul, and advance value to the value string. */
- *value = '\0';
- value++;
- child_set_env(env, envsize, cp, value);
- }
- fclose(f);
-}
-
-/*
- * 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(const char *command, struct passwd * pw, const char *term,
- const char *display, const char *auth_proto,
- const char *auth_data, const char *ttyname)
-{
- const char *shell, *cp = NULL;
- char buf[256];
- FILE *f;
- unsigned int envsize, i;
- char **env;
- extern char **environ;
- struct stat st;
- char *argv[10];
-
-#ifndef HAVE_LIBPAM /* pam_nologin handles this */
- /* Check /etc/nologin. */
- f = fopen("/etc/nologin", "r");
- if (f) {
- /* /etc/nologin exists. Print its contents and exit. */
- while (fgets(buf, sizeof(buf), f))
- fputs(buf, stderr);
- fclose(f);
- if (pw->pw_uid != 0)
- exit(254);
- }
-#endif /* HAVE_LIBPAM */
-
-#ifdef HAVE_SETLOGIN
- /* Set login name in the kernel. */
- if (setlogin(pw->pw_name) < 0)
- error("setlogin failed: %s", strerror(errno));
-#endif /* HAVE_SETLOGIN */
-
- /* Set 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) {
- if (getuid() == 0 || geteuid() == 0) {
- 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();
-
- /* Permanently switch to the desired uid. */
- permanently_set_uid(pw->pw_uid);
- }
- if (getuid() != pw->pw_uid || geteuid() != pw->pw_uid)
- fatal("Failed to set uids to %d.", (int) pw->pw_uid);
- }
- /*
- * 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 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 *));
- env[0] = NULL;
-
- if (!options.use_login) {
- /* Set basic environment. */
- child_set_env(&env, &envsize, "USER", pw->pw_name);
- child_set_env(&env, &envsize, "LOGNAME", pw->pw_name);
- child_set_env(&env, &envsize, "HOME", pw->pw_dir);
- child_set_env(&env, &envsize, "PATH", _PATH_STDPATH);
-
- snprintf(buf, sizeof buf, "%.200s/%.50s",
- _PATH_MAILDIR, pw->pw_name);
- child_set_env(&env, &envsize, "MAIL", buf);
-
- /* Normal systems set SHELL by default. */
- child_set_env(&env, &envsize, "SHELL", shell);
- }
- if (getenv("TZ"))
- child_set_env(&env, &envsize, "TZ", getenv("TZ"));
-
- /* Set custom environment options from RSA authentication. */
- while (custom_environment) {
- struct envstring *ce = custom_environment;
- char *s = ce->s;
- int i;
- for (i = 0; s[i] != '=' && s[i]; i++);
- if (s[i] == '=') {
- s[i] = 0;
- child_set_env(&env, &envsize, s, s + i + 1);
- }
- custom_environment = ce->next;
- xfree(ce->s);
- xfree(ce);
- }
-
- snprintf(buf, sizeof buf, "%.50s %d %d",
- get_remote_ipaddr(), get_remote_port(), options.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);
-
-#ifdef KRB4
- {
- extern char *ticket;
-
- if (ticket)
- child_set_env(&env, &envsize, "KRBTKFILE", ticket);
- }
-#endif /* KRB4 */
-
-#ifdef HAVE_LIBPAM
- /* Pull in any environment variables that may have been set by PAM. */
- {
- char *equals, var_name[512], var_val[512];
- char **pam_env = pam_getenvlist((pam_handle_t *)pamh);
- int i;
- for(i = 0; pam_env && pam_env[i]; i++) {
- equals = strstr(pam_env[i], "=");
- if ((strlen(pam_env[i]) < (sizeof(var_name) - 1)) && (equals != NULL))
- {
- debug("PAM environment: %s=%s", var_name, var_val);
- memset(var_name, '\0', sizeof(var_name));
- memset(var_val, '\0', sizeof(var_val));
- strncpy(var_name, pam_env[i], equals - pam_env[i]);
- strcpy(var_val, equals + 1);
- child_set_env(&env, &envsize, var_name, var_val);
- }
- }
- }
-#endif /* HAVE_LIBPAM */
-
- 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());
-
- /* read $HOME/.ssh/environment. */
- if (!options.use_login) {
- snprintf(buf, sizeof buf, "%.200s/.ssh/environment", pw->pw_dir);
- read_environment_file(&env, &envsize, buf);
- }
- if (debug_flag) {
- /* dump the environment */
- fprintf(stderr, "Environment:\n");
- for (i = 0; env[i]; i++)
- fprintf(stderr, " %.200s\n", env[i]);
- }
- /*
- * 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.
- */
- if (packet_get_connection_in() == packet_get_connection_out())
- close(packet_get_connection_in());
- else {
- close(packet_get_connection_in());
- close(packet_get_connection_out());
- }
- /*
- * Close all descriptors related to channels. They will still remain
- * open in the parent.
- */
- /* XXX better use close-on-exec? -markus */
- channel_close_all();
-
- /*
- * Close any extra file descriptors. Note that there may still be
- * descriptors left by system functions. They will be closed later.
- */
- endpwent();
- endhostent();
-
- /*
- * 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);
-
- /* 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));
-
- /*
- * 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) {
- if (debug_flag)
- fprintf(stderr, "Running /bin/sh %s\n", SSH_USER_RC);
-
- f = popen("/bin/sh " SSH_USER_RC, "w");
- if (f) {
- if (auth_proto != NULL && auth_data != NULL)
- fprintf(f, "%s %s\n", auth_proto, auth_data);
- pclose(f);
- } else
- fprintf(stderr, "Could not run %s\n", SSH_USER_RC);
- } else if (stat(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");
- if (f) {
- if (auth_proto != NULL && auth_data != NULL)
- fprintf(f, "%s %s\n", auth_proto, auth_data);
- pclose(f);
- } else
- fprintf(stderr, "Could not run %s\n", SSH_SYSTEM_RC);
- }
-#ifdef XAUTH_PATH
- else {
- /* Add authority data to .Xauthority if appropriate. */
- if (auth_proto != NULL && auth_data != NULL) {
- if (debug_flag)
- fprintf(stderr, "Running %.100s add %.100s %.100s %.100s\n",
- XAUTH_PATH, display, auth_proto, auth_data);
-
- f = popen(XAUTH_PATH " -q -", "w");
- if (f) {
- fprintf(f, "add %s %s %s\n", display, auth_proto, auth_data);
- fclose(f);
- } else
- fprintf(stderr, "Could not run %s -q -\n", XAUTH_PATH);
- }
- }
-#endif /* XAUTH_PATH */
-
- /* Get the last component of the shell name. */
- cp = strrchr(shell, '/');
- if (cp)
- cp++;
- else
- cp = shell;
- }
- /*
- * 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
- * this is a login shell.
- */
- if (!command) {
- 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);
- buf[sizeof(buf) - 1] = 0;
-
- /* Execute the shell. */
- argv[0] = buf;
- argv[1] = NULL;
- execve(shell, argv, env);
-
- /* Executing the shell failed. */
- perror(shell);
- exit(1);
-
- } else {
- /* Launch login(1). */
-
- execl(LOGIN_PROGRAM, "login", "-h", get_remote_ipaddr(),
- "-p", "-f", "--", pw->pw_name, NULL);
-
- /* Login couldn't be executed, die. */
-
- perror("login");
- exit(1);
- }
- }
- /*
- * Execute the command using the user's shell. This uses the -c
- * option to execute the command.
- */
- argv[0] = (char *) cp;
- argv[1] = "-c";
- argv[2] = (char *) command;
- argv[3] = NULL;
- execve(shell, argv, env);
- perror(shell);
- exit(1);