From 4aca87515a5083ae0e31ce3177189fd43b6d05ac Mon Sep 17 00:00:00 2001 From: Andreas Baumann Date: Sat, 3 Jan 2015 13:58:15 +0100 Subject: patch to Vanilla Tomato 1.28 --- release/src/router/busybox/loginutils/login.c | 871 +++++++++++++------------- 1 file changed, 451 insertions(+), 420 deletions(-) (limited to 'release/src/router/busybox/loginutils/login.c') diff --git a/release/src/router/busybox/loginutils/login.c b/release/src/router/busybox/loginutils/login.c index c2bada25..d57d529c 100644 --- a/release/src/router/busybox/loginutils/login.c +++ b/release/src/router/busybox/loginutils/login.c @@ -1,481 +1,512 @@ /* vi: set sw=4 ts=4: */ -#include -#include -#include -#include -#include +/* + * Licensed under GPLv2 or later, see file LICENSE in this tarball for details. + */ + +#include "libbb.h" #include -#include -#include #include #include -#include -#include -#include -#include -#include - -#include "busybox.h" -#ifdef CONFIG_SELINUX -#include -#include -#include -#include -#endif -#ifdef CONFIG_FEATURE_U_W_TMP -// import from utmp.c -static void checkutmp(int picky); -static void setutmp(const char *name, const char *line); -/* Stuff global to this file */ -struct utmp utent; +#if ENABLE_SELINUX +#include /* for is_selinux_enabled() */ +#include /* for get_default_context() */ +#include /* for security class definitions */ #endif -// login defines -#define TIMEOUT 60 -#define EMPTY_USERNAME_COUNT 10 -#define USERNAME_SIZE 32 +#if ENABLE_PAM +/* PAM may include . We may need to undefine bbox's stub define: */ +#undef setlocale +/* For some obscure reason, PAM is not in pam/xxx, but in security/xxx. + * Apparently they like to confuse people. */ +#include +#include +static const struct pam_conv conv = { + misc_conv, + NULL +}; +#endif +enum { + TIMEOUT = 60, + EMPTY_USERNAME_COUNT = 10, + USERNAME_SIZE = 32, + TTYNAME_SIZE = 32, +}; -static int check_nologin ( int amroot ); +static char* short_tty; -#if defined CONFIG_FEATURE_SECURETTY -static int check_tty ( const char *tty ); +#if ENABLE_FEATURE_UTMP +/* vv Taken from tinylogin utmp.c vv */ +/* + * read_or_build_utent - see if utmp file is correct for this process + * + * System V is very picky about the contents of the utmp file + * and requires that a slot for the current process exist. + * The utmp file is scanned for an entry with the same process + * ID. If no entry exists the process exits with a message. + * + * The "picky" flag is for network and other logins that may + * use special flags. It allows the pid checks to be overridden. + * This means that getty should never invoke login with any + * command line flags. + */ -#else -static inline int check_tty ( const char *tty ) { return 1; } +static void read_or_build_utent(struct utmp *utptr, int run_by_root) +{ + struct utmp *ut; + pid_t pid = getpid(); -#endif + setutent(); -static int is_my_tty ( const char *tty ); -static int login_prompt ( char *buf_name ); -static void motd ( void ); + /* First, try to find a valid utmp entry for this process. */ + /* If there is one, just use it. */ + while ((ut = getutent()) != NULL) + if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] + && (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS) + ) { + *utptr = *ut; /* struct copy */ + if (run_by_root) /* why only for root? */ + memset(utptr->ut_host, 0, sizeof(utptr->ut_host)); + return; + } +// Why? Do we require non-root to exec login from another +// former login process (e.g. login shell)? Some login's have +// login shells as children, so it won't work... +// if (!run_by_root) +// bb_error_msg_and_die("no utmp entry found"); + + /* Otherwise create a new one. */ + memset(utptr, 0, sizeof(*utptr)); + utptr->ut_type = LOGIN_PROCESS; + utptr->ut_pid = pid; + strncpy(utptr->ut_line, short_tty, sizeof(utptr->ut_line)); + /* This one is only 4 chars wide. Try to fit something + * remotely meaningful by skipping "tty"... */ + strncpy(utptr->ut_id, short_tty + 3, sizeof(utptr->ut_id)); + strncpy(utptr->ut_user, "LOGIN", sizeof(utptr->ut_user)); + utptr->ut_tv.tv_sec = time(NULL); +} -static void alarm_handler ( int sig ) +/* + * write_utent - put a USER_PROCESS entry in the utmp file + * + * write_utent changes the type of the current utmp entry to + * USER_PROCESS. the wtmp file will be updated as well. + */ +static void write_utent(struct utmp *utptr, const char *username) { - fprintf (stderr, "\nLogin timed out after %d seconds.\n", TIMEOUT ); - exit ( EXIT_SUCCESS ); + utptr->ut_type = USER_PROCESS; + strncpy(utptr->ut_user, username, sizeof(utptr->ut_user)); + utptr->ut_tv.tv_sec = time(NULL); + /* other fields already filled in by read_or_build_utent above */ + setutent(); + pututline(utptr); + endutent(); +#if ENABLE_FEATURE_WTMP + if (access(bb_path_wtmp_file, R_OK|W_OK) == -1) { + close(creat(bb_path_wtmp_file, 0664)); + } + updwtmp(bb_path_wtmp_file, utptr); +#endif } +#else /* !ENABLE_FEATURE_UTMP */ +#define read_or_build_utent(utptr, run_by_root) ((void)0) +#define write_utent(utptr, username) ((void)0) +#endif /* !ENABLE_FEATURE_UTMP */ - -extern int login_main(int argc, char **argv) +#if ENABLE_FEATURE_NOLOGIN +static void die_if_nologin(void) { - char tty[BUFSIZ]; - char full_tty[200]; - char fromhost[512]; - char username[USERNAME_SIZE]; - char *tmp; - int amroot; - int flag; - int failed; - int count=0; - struct passwd *pw, pw_copy; -#ifdef CONFIG_WHEEL_GROUP - struct group *grp; -#endif - int opt_preserve = 0; - int opt_fflag = 0; - char *opt_host = 0; - int alarmstarted = 0; -#ifdef CONFIG_SELINUX - int flask_enabled = is_flask_enabled(); - security_id_t sid = 0, old_tty_sid, new_tty_sid; + FILE *fp; + int c; + int empty = 1; + + fp = fopen_for_read("/etc/nologin"); + if (!fp) /* assuming it does not exist */ + return; + + while ((c = getc(fp)) != EOF) { + if (c == '\n') + bb_putchar('\r'); + bb_putchar(c); + empty = 0; + } + if (empty) + puts("\r\nSystem closed for routine maintenance\r"); + + fclose(fp); + fflush(NULL); + /* Users say that they do need this prior to exit: */ + tcdrain(STDOUT_FILENO); + exit(EXIT_FAILURE); +} +#else +static ALWAYS_INLINE void die_if_nologin(void) {} #endif - username[0]=0; - amroot = ( getuid ( ) == 0 ); - signal ( SIGALRM, alarm_handler ); - alarm ( TIMEOUT ); - alarmstarted = 1; - - while (( flag = getopt(argc, argv, "f:h:p")) != EOF ) { - switch ( flag ) { - case 'p': - opt_preserve = 1; - break; - case 'f': - /* - * username must be a seperate token - * (-f root, *NOT* -froot). --marekm - */ - if ( optarg != argv[optind-1] ) - bb_show_usage( ); - - if ( !amroot ) /* Auth bypass only if real UID is zero */ - bb_error_msg_and_die ( "-f permission denied" ); - - safe_strncpy(username, optarg, USERNAME_SIZE); - opt_fflag = 1; - break; - case 'h': - opt_host = optarg; +#if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM +static int check_securetty(void) +{ + char *buf = (char*)"/etc/securetty"; /* any non-NULL is ok */ + parser_t *parser = config_open2("/etc/securetty", fopen_for_read); + while (config_read(parser, &buf, 1, 1, "# \t", PARSE_NORMAL)) { + if (strcmp(buf, short_tty) == 0) break; - default: - bb_show_usage( ); - } + buf = NULL; } - - if (optind < argc) // user from command line (getty) - safe_strncpy(username, argv[optind], USERNAME_SIZE); - - if ( !isatty ( 0 ) || !isatty ( 1 ) || !isatty ( 2 )) - return EXIT_FAILURE; /* Must be a terminal */ - -#ifdef CONFIG_FEATURE_U_W_TMP - checkutmp ( !amroot ); -#endif - - tmp = ttyname ( 0 ); - if ( tmp && ( strncmp ( tmp, "/dev/", 5 ) == 0 )) - safe_strncpy ( tty, tmp + 5, sizeof( tty )); - else - safe_strncpy ( tty, "UNKNOWN", sizeof( tty )); - -#ifdef CONFIG_FEATURE_U_W_TMP - if ( amroot ) - memset ( utent.ut_host, 0, sizeof utent.ut_host ); -#endif - - if ( opt_host ) { -#ifdef CONFIG_FEATURE_U_W_TMP - safe_strncpy ( utent.ut_host, opt_host, sizeof( utent. ut_host )); + config_close(parser); + /* buf != NULL here if config file was not found, empty + * or line was found which equals short_tty */ + return buf != NULL; +} +#else +static ALWAYS_INLINE int check_securetty(void) { return 1; } #endif - snprintf ( fromhost, sizeof( fromhost ) - 1, " on `%.100s' from `%.200s'", tty, opt_host ); - } - else - snprintf ( fromhost, sizeof( fromhost ) - 1, " on `%.100s'", tty ); - - setpgrp(); - - openlog ( "login", LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH ); - - while ( 1 ) { - failed = 0; - - if ( !username[0] ) - if(!login_prompt ( username )) - return EXIT_FAILURE; - if ( !alarmstarted && ( TIMEOUT > 0 )) { - alarm ( TIMEOUT ); - alarmstarted = 1; - } - - if (!( pw = getpwnam ( username ))) { - pw_copy.pw_name = "UNKNOWN"; - pw_copy.pw_passwd = "!"; - opt_fflag = 0; - failed = 1; - } else - pw_copy = *pw; - - pw = &pw_copy; - - if (( pw-> pw_passwd [0] == '!' ) || ( pw-> pw_passwd[0] == '*' )) - failed = 1; - - if ( opt_fflag ) { - opt_fflag = 0; - goto auth_ok; - } - - if (!failed && ( pw-> pw_uid == 0 ) && ( !check_tty ( tty ))) - failed = 1; - - /* Don't check the password if password entry is empty (!) */ - if ( !pw-> pw_passwd[0] ) - goto auth_ok; - - /* authorization takes place here */ - if ( correct_password ( pw )) - goto auth_ok; - - failed = 1; - -auth_ok: - if ( !failed) - break; +#if ENABLE_SELINUX +static void initselinux(char *username, char *full_tty, + security_context_t *user_sid) +{ + security_context_t old_tty_sid, new_tty_sid; - { // delay next try - time_t start, now; - - time ( &start ); - now = start; - while ( difftime ( now, start ) < FAIL_DELAY) { - sleep ( FAIL_DELAY ); - time ( &now ); - } - } + if (!is_selinux_enabled()) + return; - puts("Login incorrect"); - username[0] = 0; - if ( ++count == 3 ) { - syslog ( LOG_WARNING, "invalid password for `%s'%s\n", pw->pw_name, fromhost); - return EXIT_FAILURE; + if (get_default_context(username, NULL, user_sid)) { + bb_error_msg_and_die("cannot get SID for %s", username); } + if (getfilecon(full_tty, &old_tty_sid) < 0) { + bb_perror_msg_and_die("getfilecon(%s) failed", full_tty); } - - alarm ( 0 ); - if ( check_nologin ( pw-> pw_uid == 0 )) - return EXIT_FAILURE; - -#ifdef CONFIG_FEATURE_U_W_TMP - setutmp ( username, tty ); -#endif -#ifdef CONFIG_SELINUX - if (flask_enabled) - { - struct stat st; - - if (get_default_sid(username, 0, &sid)) - { - fprintf(stderr, "Unable to get SID for %s\n", username); - exit(1); - } - if (stat_secure(tty, &st, &old_tty_sid)) - { - fprintf(stderr, "stat_secure(%.100s) failed: %.100s\n", tty, strerror(errno)); - return EXIT_FAILURE; - } - if (security_change_sid (sid, old_tty_sid, SECCLASS_CHR_FILE, &new_tty_sid) != 0) - { - fprintf(stderr, "security_change_sid(%.100s) failed: %.100s\n", tty, strerror(errno)); - return EXIT_FAILURE; - } - if(chsid(tty, new_tty_sid) != 0) - { - fprintf(stderr, "chsid(%.100s, %d) failed: %.100s\n", tty, new_tty_sid, strerror(errno)); - return EXIT_FAILURE; - } + if (security_compute_relabel(*user_sid, old_tty_sid, + SECCLASS_CHR_FILE, &new_tty_sid) != 0) { + bb_perror_msg_and_die("security_change_sid(%s) failed", full_tty); + } + if (setfilecon(full_tty, new_tty_sid) != 0) { + bb_perror_msg_and_die("chsid(%s, %s) failed", full_tty, new_tty_sid); } - else - sid = 0; -#endif - - if ( *tty != '/' ) - snprintf ( full_tty, sizeof( full_tty ) - 1, "/dev/%s", tty); - else - safe_strncpy ( full_tty, tty, sizeof( full_tty ) - 1 ); - - if ( !is_my_tty ( full_tty )) - syslog ( LOG_ERR, "unable to determine TTY name, got %s\n", full_tty ); - - /* Try these, but don't complain if they fail - * (for example when the root fs is read only) */ - chown ( full_tty, pw-> pw_uid, pw-> pw_gid ); - chmod ( full_tty, 0600 ); - - change_identity ( pw ); - setup_environment ( pw-> pw_shell, 1, !opt_preserve, pw ); - - motd ( ); - signal ( SIGALRM, SIG_DFL ); /* default alarm signal */ - - if ( pw-> pw_uid == 0 ) - syslog ( LOG_INFO, "root login %s\n", fromhost ); - - run_shell ( pw-> pw_shell, 1, 0, 0 -#ifdef CONFIG_SELINUX - , sid -#endif - ); /* exec the shell finally. */ - - return EXIT_FAILURE; } +#endif - - -static int login_prompt ( char *buf_name ) +#if ENABLE_LOGIN_SCRIPTS +static void run_login_script(struct passwd *pw, char *full_tty) { - char buf [1024]; - char *sp, *ep; - int i; - - for(i=0; ipw_name); + xsetenv("LOGIN_UID", utoa(pw->pw_uid)); + xsetenv("LOGIN_GID", utoa(pw->pw_gid)); + xsetenv("LOGIN_SHELL", pw->pw_shell); + spawn_and_wait(t_argv); /* NOMMU-friendly */ + unsetenv("LOGIN_TTY"); + unsetenv("LOGIN_USER"); + unsetenv("LOGIN_UID"); + unsetenv("LOGIN_GID"); + unsetenv("LOGIN_SHELL"); } - return 0; } +#else +void run_login_script(struct passwd *pw, char *full_tty); +#endif - -static int check_nologin ( int amroot ) +static void get_username_or_die(char *buf, int size_buf) { - if ( access ( bb_path_nologin_file, F_OK ) == 0 ) { - FILE *fp; - int c; - - if (( fp = fopen ( bb_path_nologin_file, "r" ))) { - while (( c = getc ( fp )) != EOF ) - putchar (( c == '\n' ) ? '\r' : c ); - - fflush ( stdout ); - fclose ( fp ); - } else { - puts ( "\r\nSystem closed for routine maintenance.\r" ); + int c, cntdown; + + cntdown = EMPTY_USERNAME_COUNT; + prompt: + print_login_prompt(); + /* skip whitespace */ + do { + c = getchar(); + if (c == EOF) exit(EXIT_FAILURE); + if (c == '\n') { + if (!--cntdown) exit(EXIT_FAILURE); + goto prompt; } - if ( !amroot ) - return 1; - - puts ( "\r\n[Disconnect bypassed -- root login allowed.]\r" ); - } - return 0; + } while (isspace(c)); + + *buf++ = c; + if (!fgets(buf, size_buf-2, stdin)) + exit(EXIT_FAILURE); + if (!strchr(buf, '\n')) + exit(EXIT_FAILURE); + while (isgraph(*buf)) buf++; + *buf = '\0'; } -#ifdef CONFIG_FEATURE_SECURETTY - -static int check_tty ( const char *tty ) +static void motd(void) { - FILE *fp; - int i; - char buf[BUFSIZ]; - - if (( fp = fopen ( bb_path_securetty_file, "r" ))) { - while ( fgets ( buf, sizeof( buf ) - 1, fp )) { - for ( i = bb_strlen( buf ) - 1; i >= 0; --i ) { - if ( !isspace ( buf[i] )) - break; - } - buf[++i] = '\0'; - if (( buf [0] == '\0' ) || ( buf [0] == '#' )) - continue; - - if ( strcmp ( buf, tty ) == 0 ) { - fclose ( fp ); - return 1; - } - } - fclose(fp); - return 0; + int fd; + + fd = open(bb_path_motd_file, O_RDONLY); + if (fd >= 0) { + fflush(stdout); + bb_copyfd_eof(fd, STDOUT_FILENO); + close(fd); } - /* A missing securetty file is not an error. */ - return 1; } -#endif - -/* returns 1 if true */ -static int is_my_tty ( const char *tty ) +static void alarm_handler(int sig UNUSED_PARAM) { - struct stat by_name, by_fd; - - if ( stat ( tty, &by_name ) || fstat ( 0, &by_fd )) - return 0; - - if ( by_name. st_rdev != by_fd. st_rdev ) - return 0; - else - return 1; + /* This is the escape hatch! Poor serial line users and the like + * arrive here when their connection is broken. + * We don't want to block here */ + ndelay_on(1); + printf("\r\nLogin timed out after %d seconds\r\n", TIMEOUT); + fflush(stdout); + /* unix API is brain damaged regarding O_NONBLOCK, + * we should undo it, or else we can affect other processes */ + ndelay_off(1); + _exit(EXIT_SUCCESS); } - -static void motd ( ) +int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; +int login_main(int argc UNUSED_PARAM, char **argv) { - FILE *fp; - register int c; + enum { + LOGIN_OPT_f = (1<<0), + LOGIN_OPT_h = (1<<1), + LOGIN_OPT_p = (1<<2), + }; + char *fromhost; + char username[USERNAME_SIZE]; + const char *tmp; + int run_by_root; + unsigned opt; + int count = 0; + struct passwd *pw; + char *opt_host = opt_host; /* for compiler */ + char *opt_user = opt_user; /* for compiler */ + char *full_tty; + USE_SELINUX(security_context_t user_sid = NULL;) + USE_FEATURE_UTMP(struct utmp utent;) +#if ENABLE_PAM + int pamret; + pam_handle_t *pamh; + const char *pamuser; + const char *failed_msg; + struct passwd pwdstruct; + char pwdbuf[256]; +#endif - if (( fp = fopen ( bb_path_motd_file, "r" ))) { - while (( c = getc ( fp )) != EOF ) - putchar ( c ); - fclose ( fp ); + username[0] = '\0'; + signal(SIGALRM, alarm_handler); + alarm(TIMEOUT); + + /* More of suid paranoia if called by non-root: */ + /* Clear dangerous stuff, set PATH */ + run_by_root = !sanitize_env_if_suid(); + + /* Mandatory paranoia for suid applet: + * ensure that fd# 0,1,2 are opened (at least to /dev/null) + * and any extra open fd's are closed. + * (The name of the function is misleading. Not daemonizing here.) */ + bb_daemonize_or_rexec(DAEMON_ONLY_SANITIZE | DAEMON_CLOSE_EXTRA_FDS, NULL); + + opt = getopt32(argv, "f:h:p", &opt_user, &opt_host); + if (opt & LOGIN_OPT_f) { + if (!run_by_root) + bb_error_msg_and_die("-f is for root only"); + safe_strncpy(username, opt_user, sizeof(username)); } -} + argv += optind; + if (argv[0]) /* user from command line (getty) */ + safe_strncpy(username, argv[0], sizeof(username)); + /* Let's find out and memorize our tty */ + if (!isatty(STDIN_FILENO) || !isatty(STDOUT_FILENO) || !isatty(STDERR_FILENO)) + return EXIT_FAILURE; /* Must be a terminal */ + full_tty = xmalloc_ttyname(STDIN_FILENO); + if (!full_tty) + full_tty = xstrdup("UNKNOWN"); + short_tty = full_tty; + if (strncmp(full_tty, "/dev/", 5) == 0) + short_tty += 5; + + read_or_build_utent(&utent, run_by_root); + + if (opt & LOGIN_OPT_h) { + USE_FEATURE_UTMP(safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));) + fromhost = xasprintf(" on '%s' from '%s'", short_tty, opt_host); + } else { + fromhost = xasprintf(" on '%s'", short_tty); + } -#ifdef CONFIG_FEATURE_U_W_TMP -// vv Taken from tinylogin utmp.c vv - -#define _WTMP_FILE "/var/log/wtmp" - -#define NO_UTENT \ - "No utmp entry. You must exec \"login\" from the lowest level \"sh\"" -#define NO_TTY \ - "Unable to determine your tty name." - -/* - * checkutmp - see if utmp file is correct for this process - * - * System V is very picky about the contents of the utmp file - * and requires that a slot for the current process exist. - * The utmp file is scanned for an entry with the same process - * ID. If no entry exists the process exits with a message. - * - * The "picky" flag is for network and other logins that may - * use special flags. It allows the pid checks to be overridden. - * This means that getty should never invoke login with any - * command line flags. - */ + /* Was breaking "login " from shell command line: */ + /*bb_setpgrp();*/ -static void checkutmp(int picky) -{ - char *line; - struct utmp *ut; - pid_t pid = getpid(); + openlog(applet_name, LOG_PID | LOG_CONS, LOG_AUTH); - setutent(); + while (1) { + /* flush away any type-ahead (as getty does) */ + ioctl(0, TCFLSH, TCIFLUSH); - /* First, try to find a valid utmp entry for this process. */ - while ((ut = getutent())) - if (ut->ut_pid == pid && ut->ut_line[0] && ut->ut_id[0] && - (ut->ut_type == LOGIN_PROCESS || ut->ut_type == USER_PROCESS)) - break; + if (!username[0]) + get_username_or_die(username, sizeof(username)); - /* If there is one, just use it, otherwise create a new one. */ - if (ut) { - utent = *ut; - } else { - if (picky) { - puts(NO_UTENT); - exit(1); +#if ENABLE_PAM + pamret = pam_start("login", username, &conv, &pamh); + if (pamret != PAM_SUCCESS) { + failed_msg = "start"; + goto pam_auth_failed; } - line = ttyname(0); - if (!line) { - puts(NO_TTY); - exit(1); + /* set TTY (so things like securetty work) */ + pamret = pam_set_item(pamh, PAM_TTY, short_tty); + if (pamret != PAM_SUCCESS) { + failed_msg = "set_item(TTY)"; + goto pam_auth_failed; + } + pamret = pam_authenticate(pamh, 0); + if (pamret != PAM_SUCCESS) { + failed_msg = "authenticate"; + goto pam_auth_failed; + /* TODO: or just "goto auth_failed" + * since user seems to enter wrong password + * (in this case pamret == 7) + */ + } + /* check that the account is healthy */ + pamret = pam_acct_mgmt(pamh, 0); + if (pamret != PAM_SUCCESS) { + failed_msg = "acct_mgmt"; + goto pam_auth_failed; + } + /* read user back */ + pamuser = NULL; + /* gcc: "dereferencing type-punned pointer breaks aliasing rules..." + * thus we cast to (void*) */ + if (pam_get_item(pamh, PAM_USER, (void*)&pamuser) != PAM_SUCCESS) { + failed_msg = "get_item(USER)"; + goto pam_auth_failed; + } + if (!pamuser || !pamuser[0]) + goto auth_failed; + safe_strncpy(username, pamuser, sizeof(username)); + /* Don't use "pw = getpwnam(username);", + * PAM is said to be capable of destroying static storage + * used by getpwnam(). We are using safe(r) function */ + pw = NULL; + getpwnam_r(username, &pwdstruct, pwdbuf, sizeof(pwdbuf), &pw); + if (!pw) + goto auth_failed; + pamret = pam_open_session(pamh, 0); + if (pamret != PAM_SUCCESS) { + failed_msg = "open_session"; + goto pam_auth_failed; + } + pamret = pam_setcred(pamh, PAM_ESTABLISH_CRED); + if (pamret != PAM_SUCCESS) { + failed_msg = "setcred"; + goto pam_auth_failed; + } + break; /* success, continue login process */ + + pam_auth_failed: + bb_error_msg("pam_%s call failed: %s (%d)", failed_msg, + pam_strerror(pamh, pamret), pamret); + safe_strncpy(username, "UNKNOWN", sizeof(username)); +#else /* not PAM */ + pw = getpwnam(username); + if (!pw) { + strcpy(username, "UNKNOWN"); + goto fake_it; } - if (strncmp(line, "/dev/", 5) == 0) - line += 5; - memset((void *) &utent, 0, sizeof utent); - utent.ut_type = LOGIN_PROCESS; - utent.ut_pid = pid; - strncpy(utent.ut_line, line, sizeof utent.ut_line); - /* XXX - assumes /dev/tty?? */ - strncpy(utent.ut_id, utent.ut_line + 3, sizeof utent.ut_id); - strncpy(utent.ut_user, "LOGIN", sizeof utent.ut_user); - time(&utent.ut_time); - } -} -/* - * setutmp - put a USER_PROCESS entry in the utmp file - * - * setutmp changes the type of the current utmp entry to - * USER_PROCESS. the wtmp file will be updated as well. - */ + if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*') + goto auth_failed; -static void setutmp(const char *name, const char *line) -{ - utent.ut_type = USER_PROCESS; - strncpy(utent.ut_user, name, sizeof utent.ut_user); - time(&utent.ut_time); - /* other fields already filled in by checkutmp above */ - setutent(); - pututline(&utent); - endutent(); - updwtmp(_WTMP_FILE, &utent); + if (opt & LOGIN_OPT_f) + break; /* -f USER: success without asking passwd */ + + if (pw->pw_uid == 0 && !check_securetty()) + goto auth_failed; + + /* Don't check the password if password entry is empty (!) */ + if (!pw->pw_passwd[0]) + break; + fake_it: + /* authorization takes place here */ + if (correct_password(pw)) + break; +#endif /* ENABLE_PAM */ + auth_failed: + opt &= ~LOGIN_OPT_f; + bb_do_delay(FAIL_DELAY); + /* TODO: doesn't sound like correct English phrase to me */ + puts("Login incorrect"); + if (++count == 3) { + syslog(LOG_WARNING, "invalid password for '%s'%s", + username, fromhost); + return EXIT_FAILURE; + } + username[0] = '\0'; + } /* while (1) */ + + alarm(0); + /* We can ignore /etc/nologin if we are logging in as root, + * it doesn't matter whether we are run by root or not */ + if (pw->pw_uid != 0) + die_if_nologin(); + + write_utent(&utent, username); + + USE_SELINUX(initselinux(username, full_tty, &user_sid)); + + /* Try these, but don't complain if they fail. + * _f_chown is safe wrt race t=ttyname(0);...;chown(t); */ + fchown(0, pw->pw_uid, pw->pw_gid); + fchmod(0, 0600); + + /* We trust environment only if we run by root */ + if (ENABLE_LOGIN_SCRIPTS && run_by_root) + run_login_script(pw, full_tty); + + change_identity(pw); + tmp = pw->pw_shell; + if (!tmp || !*tmp) + tmp = DEFAULT_SHELL; + /* setup_environment params: shell, clear_env, change_env, pw */ + setup_environment(tmp, !(opt & LOGIN_OPT_p), 1, pw); + + motd(); + + if (pw->pw_uid == 0) + syslog(LOG_INFO, "root login%s", fromhost); + + /* well, a simple setexeccon() here would do the job as well, + * but let's play the game for now */ + USE_SELINUX(set_current_security_context(user_sid);) + + // util-linux login also does: + // /* start new session */ + // setsid(); + // /* TIOCSCTTY: steal tty from other process group */ + // if (ioctl(0, TIOCSCTTY, 1)) error_msg... + // BBox login used to do this (see above): + // bb_setpgrp(); + // If this stuff is really needed, add it and explain why! + + /* Set signals to defaults */ + /* Non-ignored signals revert to SIG_DFL on exec anyway */ + /*signal(SIGALRM, SIG_DFL);*/ + + /* Is this correct? This way user can ctrl-c out of /etc/profile, + * potentially creating security breach (tested with bash 3.0). + * But without this, bash 3.0 will not enable ctrl-c either. + * Maybe bash is buggy? + * Need to find out what standards say about /bin/login - + * should we leave SIGINT etc enabled or disabled? */ + signal(SIGINT, SIG_DFL); + + /* Exec login shell with no additional parameters */ + run_shell(tmp, 1, NULL, NULL); + + /* return EXIT_FAILURE; - not reached */ } -#endif /* CONFIG_FEATURE_U_W_TMP */ -- cgit v1.2.3-54-g00ecf