mirror of
https://github.com/sheumann/hush.git
synced 2024-08-17 00:29:03 +00:00
function old new delta getopt32 1370 1385 +15 sulogin_main 490 494 +4 realpath_main 84 86 +2 sleep_main 76 77 +1 mt_main 256 257 +1 printenv_main 75 74 -1 fdformat_main 546 545 -1 usleep_main 44 42 -2 setlogcons_main 77 75 -2 ed_main 2654 2649 -5 deallocvt_main 69 64 -5 addgroup_main 373 368 -5 mkfs_minix_main 2989 2982 -7 tail_main 1221 1213 -8 sv_main 1254 1241 -13 du_main 348 328 -20 tftp_main 325 302 -23 split_main 581 558 -23 nc_main 1000 977 -23 diff_main 891 868 -23 arping_main 1797 1770 -27 ls_main 893 847 -46 od_main 2797 2750 -47 readprofile_main 1944 1895 -49 tcpudpsvd_main 1973 1922 -51 udhcpc_main 2590 2513 -77 grep_main 824 722 -102 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 5/22 up/down: 23/-560) Total: -537 bytes text data bss dec hex filename 796973 658 7428 805059 c48c3 busybox_old 796479 662 7420 804561 c46d1 busybox_unstripped
503 lines
13 KiB
C
503 lines
13 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
#include <syslog.h>
|
|
#include <utmp.h>
|
|
#include <sys/resource.h>
|
|
|
|
#if ENABLE_SELINUX
|
|
#include <selinux/selinux.h> /* for is_selinux_enabled() */
|
|
#include <selinux/get_context_list.h> /* for get_default_context() */
|
|
#include <selinux/flask.h> /* for security class definitions */
|
|
#endif
|
|
|
|
#if ENABLE_PAM
|
|
/* PAM may include <locale.h>. 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 <security/pam_appl.h>
|
|
#include <security/pam_misc.h>
|
|
static const struct pam_conv conv = {
|
|
misc_conv,
|
|
NULL
|
|
};
|
|
#endif
|
|
|
|
enum {
|
|
TIMEOUT = 60,
|
|
EMPTY_USERNAME_COUNT = 10,
|
|
USERNAME_SIZE = 32,
|
|
TTYNAME_SIZE = 32,
|
|
};
|
|
|
|
static char* short_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.
|
|
*/
|
|
|
|
static void read_or_build_utent(struct utmp *utptr, int picky)
|
|
{
|
|
struct utmp *ut;
|
|
pid_t pid = getpid();
|
|
|
|
setutent();
|
|
|
|
/* 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 there is one, just use it, otherwise create a new one. */
|
|
if (ut) {
|
|
*utptr = *ut;
|
|
} else {
|
|
if (picky)
|
|
bb_error_msg_and_die("no utmp entry found");
|
|
|
|
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_time = time(NULL);
|
|
}
|
|
if (!picky) /* root login */
|
|
memset(utptr->ut_host, 0, sizeof(utptr->ut_host));
|
|
}
|
|
|
|
/*
|
|
* 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)
|
|
{
|
|
utptr->ut_type = USER_PROCESS;
|
|
strncpy(utptr->ut_user, username, sizeof(utptr->ut_user));
|
|
utptr->ut_time = 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, picky) ((void)0)
|
|
#define write_utent(utptr, username) ((void)0)
|
|
#endif /* !ENABLE_FEATURE_UTMP */
|
|
|
|
#if ENABLE_FEATURE_NOLOGIN
|
|
static void die_if_nologin(void)
|
|
{
|
|
FILE *fp;
|
|
int c;
|
|
|
|
if (access("/etc/nologin", F_OK))
|
|
return;
|
|
|
|
fp = fopen("/etc/nologin", "r");
|
|
if (fp) {
|
|
while ((c = getc(fp)) != EOF)
|
|
bb_putchar((c=='\n') ? '\r' : c);
|
|
fflush(stdout);
|
|
fclose(fp);
|
|
} else
|
|
puts("\r\nSystem closed for routine maintenance\r");
|
|
exit(1);
|
|
}
|
|
#else
|
|
static ALWAYS_INLINE void die_if_nologin(void) {}
|
|
#endif
|
|
|
|
#if ENABLE_FEATURE_SECURETTY && !ENABLE_PAM
|
|
static int check_securetty(void)
|
|
{
|
|
FILE *fp;
|
|
int i;
|
|
char buf[256];
|
|
|
|
fp = fopen("/etc/securetty", "r");
|
|
if (!fp) {
|
|
/* A missing securetty file is not an error. */
|
|
return 1;
|
|
}
|
|
while (fgets(buf, sizeof(buf)-1, fp)) {
|
|
for (i = strlen(buf)-1; i >= 0; --i) {
|
|
if (!isspace(buf[i]))
|
|
break;
|
|
}
|
|
buf[++i] = '\0';
|
|
if (!buf[0] || (buf[0] == '#'))
|
|
continue;
|
|
if (strcmp(buf, short_tty) == 0) {
|
|
fclose(fp);
|
|
return 1;
|
|
}
|
|
}
|
|
fclose(fp);
|
|
return 0;
|
|
}
|
|
#else
|
|
static ALWAYS_INLINE int check_securetty(void) { return 1; }
|
|
#endif
|
|
|
|
static void get_username_or_die(char *buf, int size_buf)
|
|
{
|
|
int c, cntdown;
|
|
|
|
cntdown = EMPTY_USERNAME_COUNT;
|
|
prompt:
|
|
print_login_prompt();
|
|
/* skip whitespace */
|
|
do {
|
|
c = getchar();
|
|
if (c == EOF) exit(1);
|
|
if (c == '\n') {
|
|
if (!--cntdown) exit(1);
|
|
goto prompt;
|
|
}
|
|
} while (isspace(c));
|
|
|
|
*buf++ = c;
|
|
if (!fgets(buf, size_buf-2, stdin))
|
|
exit(1);
|
|
if (!strchr(buf, '\n'))
|
|
exit(1);
|
|
while (isgraph(*buf)) buf++;
|
|
*buf = '\0';
|
|
}
|
|
|
|
static void motd(void)
|
|
{
|
|
int fd;
|
|
|
|
fd = open(bb_path_motd_file, O_RDONLY);
|
|
if (fd >= 0) {
|
|
fflush(stdout);
|
|
bb_copyfd_eof(fd, STDOUT_FILENO);
|
|
close(fd);
|
|
}
|
|
}
|
|
|
|
static void alarm_handler(int sig ATTRIBUTE_UNUSED)
|
|
{
|
|
/* 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);
|
|
}
|
|
|
|
int login_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
|
|
int login_main(int argc ATTRIBUTE_UNUSED, char **argv)
|
|
{
|
|
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 amroot;
|
|
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[TTYNAME_SIZE];
|
|
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
|
|
|
|
short_tty = full_tty;
|
|
username[0] = '\0';
|
|
signal(SIGALRM, alarm_handler);
|
|
alarm(TIMEOUT);
|
|
|
|
/* More of suid paranoia if called by non-root */
|
|
amroot = !sanitize_env_if_suid(); /* Clear dangerous stuff, set PATH */
|
|
|
|
/* 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 (!amroot)
|
|
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(0) || !isatty(1) || !isatty(2))
|
|
return EXIT_FAILURE; /* Must be a terminal */
|
|
safe_strncpy(full_tty, "UNKNOWN", sizeof(full_tty));
|
|
tmp = ttyname(0);
|
|
if (tmp) {
|
|
safe_strncpy(full_tty, tmp, sizeof(full_tty));
|
|
if (strncmp(full_tty, "/dev/", 5) == 0)
|
|
short_tty = full_tty + 5;
|
|
}
|
|
|
|
read_or_build_utent(&utent, !amroot);
|
|
|
|
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);
|
|
|
|
/* Was breaking "login <username>" from shell command line: */
|
|
/*bb_setpgrp();*/
|
|
|
|
openlog(applet_name, LOG_PID | LOG_CONS | LOG_NOWAIT, LOG_AUTH);
|
|
|
|
while (1) {
|
|
/* flush away any type-ahead (as getty does) */
|
|
ioctl(0, TCFLSH, TCIFLUSH);
|
|
|
|
if (!username[0])
|
|
get_username_or_die(username, sizeof(username));
|
|
|
|
#if ENABLE_PAM
|
|
pamret = pam_start("login", username, &conv, &pamh);
|
|
if (pamret != PAM_SUCCESS) {
|
|
failed_msg = "start";
|
|
goto pam_auth_failed;
|
|
}
|
|
/* 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 (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*')
|
|
goto auth_failed;
|
|
|
|
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';
|
|
}
|
|
|
|
alarm(0);
|
|
if (!amroot)
|
|
die_if_nologin();
|
|
|
|
write_utent(&utent, username);
|
|
|
|
#if ENABLE_SELINUX
|
|
if (is_selinux_enabled()) {
|
|
security_context_t old_tty_sid, new_tty_sid;
|
|
|
|
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);
|
|
}
|
|
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);
|
|
}
|
|
}
|
|
#endif
|
|
/* 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 && amroot) {
|
|
char *t_argv[2];
|
|
|
|
t_argv[0] = getenv("LOGIN_PRE_SUID_SCRIPT");
|
|
if (t_argv[0]) {
|
|
t_argv[1] = NULL;
|
|
xsetenv("LOGIN_TTY", full_tty);
|
|
xsetenv("LOGIN_USER", pw->pw_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");
|
|
}
|
|
}
|
|
|
|
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);
|
|
#if ENABLE_SELINUX
|
|
/* well, a simple setexeccon() here would do the job as well,
|
|
* but let's play the game for now */
|
|
set_current_security_context(user_sid);
|
|
#endif
|
|
|
|
// 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 */
|
|
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 it 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 */
|
|
}
|