mirror of
https://github.com/sheumann/hush.git
synced 2024-08-21 11:28:57 +00:00
login: make it saner and smaller by ~0.5k.
This commit is contained in:
parent
6bbd174593
commit
9a9edf200b
@ -29,59 +29,59 @@
|
||||
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
// import from utmp.c
|
||||
static void checkutmp(int picky);
|
||||
static void setutmp(const char *name, const char *line);
|
||||
/* Stuff global to this file */
|
||||
static struct utmp utent;
|
||||
static void read_or_build_utent(int picky);
|
||||
static void write_utent(const char *username);
|
||||
#endif
|
||||
|
||||
enum {
|
||||
TIMEOUT = 60,
|
||||
EMPTY_USERNAME_COUNT = 10,
|
||||
USERNAME_SIZE = 32,
|
||||
TTYNAME_SIZE = 32,
|
||||
};
|
||||
|
||||
static int check_nologin(int amroot);
|
||||
static void die_if_nologin_and_non_root(int amroot);
|
||||
|
||||
#if defined CONFIG_FEATURE_SECURETTY
|
||||
static int check_tty(const char *tty);
|
||||
static int check_securetty(void);
|
||||
|
||||
#else
|
||||
static inline int check_tty(const char *tty) { return 1; }
|
||||
static inline int check_securetty(void) { return 1; }
|
||||
|
||||
#endif
|
||||
|
||||
static int is_my_tty(const char *tty);
|
||||
static int login_prompt(char *buf_name);
|
||||
static int is_my_tty(void);
|
||||
static void get_username_or_die(char *buf, int size_buf);
|
||||
static void motd(void);
|
||||
|
||||
|
||||
static void alarm_handler(int sig ATTRIBUTE_UNUSED)
|
||||
{
|
||||
fprintf(stderr, "\r\nLogin timed out after %s seconds\r\n", TIMEOUT);
|
||||
fprintf(stderr, "\r\nLogin timed out after %d seconds\r\n", TIMEOUT);
|
||||
exit(EXIT_SUCCESS);
|
||||
}
|
||||
|
||||
|
||||
static char full_tty[TTYNAME_SIZE];
|
||||
static char* short_tty = full_tty;
|
||||
|
||||
|
||||
int login_main(int argc, char **argv)
|
||||
{
|
||||
char tty[BUFSIZ];
|
||||
char full_tty[200];
|
||||
char fromhost[512];
|
||||
char username[USERNAME_SIZE];
|
||||
const char *tmp;
|
||||
int amroot;
|
||||
int flag;
|
||||
int failed;
|
||||
int count = 0;
|
||||
struct passwd *pw, pw_copy;
|
||||
struct passwd *pw;
|
||||
#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
|
||||
security_context_t user_sid = NULL;
|
||||
#endif
|
||||
@ -90,7 +90,6 @@ int login_main(int argc, char **argv)
|
||||
amroot = (getuid() == 0);
|
||||
signal(SIGALRM, alarm_handler);
|
||||
alarm(TIMEOUT);
|
||||
alarmstarted = 1;
|
||||
|
||||
while ((flag = getopt(argc, argv, "f:h:p")) != EOF) {
|
||||
switch (flag) {
|
||||
@ -105,10 +104,10 @@ int login_main(int argc, char **argv)
|
||||
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");
|
||||
if (!amroot) /* Auth bypass only if real UID is zero */
|
||||
bb_error_msg_and_die("-f is for root only");
|
||||
|
||||
safe_strncpy(username, optarg, USERNAME_SIZE);
|
||||
safe_strncpy(username, optarg, sizeof(username));
|
||||
opt_fflag = 1;
|
||||
break;
|
||||
case 'h':
|
||||
@ -118,113 +117,83 @@ int login_main(int argc, char **argv)
|
||||
bb_show_usage();
|
||||
}
|
||||
}
|
||||
|
||||
if (optind < argc) /* user from command line (getty) */
|
||||
safe_strncpy(username, argv[optind], USERNAME_SIZE);
|
||||
safe_strncpy(username, argv[optind], sizeof(username));
|
||||
|
||||
/* Let's find out and memorize our tty */
|
||||
if (!isatty(0) || !isatty(1) || !isatty(2))
|
||||
return EXIT_FAILURE; /* Must be a terminal */
|
||||
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
checkutmp(!amroot);
|
||||
#endif
|
||||
|
||||
safe_strncpy(full_tty, "UNKNOWN", sizeof(full_tty));
|
||||
tmp = ttyname(0);
|
||||
if (tmp && (strncmp(tmp, "/dev/", 5) == 0))
|
||||
safe_strncpy(tty, tmp + 5, sizeof(tty));
|
||||
else if (tmp && *tmp == '/')
|
||||
safe_strncpy(tty, tmp, sizeof(tty));
|
||||
else
|
||||
safe_strncpy(tty, "UNKNOWN", sizeof(tty));
|
||||
if (tmp) {
|
||||
safe_strncpy(full_tty, tmp, sizeof(full_tty));
|
||||
if (strncmp(full_tty, "/dev/", 5) == 0)
|
||||
short_tty = full_tty + 5;
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
if (amroot)
|
||||
memset(utent.ut_host, 0, sizeof(utent.ut_host));
|
||||
#endif
|
||||
if (ENABLE_FEATURE_UTMP) {
|
||||
read_or_build_utent(!amroot);
|
||||
if (amroot)
|
||||
memset(utent.ut_host, 0, sizeof(utent.ut_host));
|
||||
}
|
||||
|
||||
if (opt_host) {
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
|
||||
#endif
|
||||
if (ENABLE_FEATURE_UTMP)
|
||||
safe_strncpy(utent.ut_host, opt_host, sizeof(utent.ut_host));
|
||||
snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s' from "
|
||||
"`%.200s'", tty, opt_host);
|
||||
"`%.200s'", short_tty, opt_host);
|
||||
}
|
||||
else
|
||||
snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", tty);
|
||||
snprintf(fromhost, sizeof(fromhost)-1, " on `%.100s'", short_tty);
|
||||
|
||||
bb_setpgrp;
|
||||
|
||||
openlog(bb_applet_name, 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;
|
||||
}
|
||||
get_username_or_die(username, sizeof(username));
|
||||
|
||||
pw = getpwnam(username);
|
||||
if (!pw) {
|
||||
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;
|
||||
safe_strncpy(username, "UNKNOWN", sizeof(username));
|
||||
goto auth_failed;
|
||||
}
|
||||
|
||||
if (!failed && (pw->pw_uid == 0) && (!check_tty(tty)))
|
||||
failed = 1;
|
||||
if (pw->pw_passwd[0] == '!' || pw->pw_passwd[0] == '*')
|
||||
goto auth_failed;
|
||||
|
||||
if (opt_fflag)
|
||||
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])
|
||||
goto auth_ok;
|
||||
break;
|
||||
|
||||
/* authorization takes place here */
|
||||
if (correct_password(pw))
|
||||
goto auth_ok;
|
||||
|
||||
failed = 1;
|
||||
|
||||
auth_ok:
|
||||
if (!failed)
|
||||
break;
|
||||
break;
|
||||
|
||||
auth_failed:
|
||||
opt_fflag = 0;
|
||||
bb_do_delay(FAIL_DELAY);
|
||||
puts("Login incorrect");
|
||||
username[0] = 0;
|
||||
if (++count == 3) {
|
||||
syslog(LOG_WARNING, "invalid password for `%s'%s", pw->pw_name, fromhost);
|
||||
syslog(LOG_WARNING, "invalid password for `%s'%s",
|
||||
username, fromhost);
|
||||
return EXIT_FAILURE;
|
||||
}
|
||||
username[0] = '\0';
|
||||
}
|
||||
|
||||
alarm(0);
|
||||
if (check_nologin(pw->pw_uid == 0))
|
||||
return EXIT_FAILURE;
|
||||
die_if_nologin_and_non_root(pw->pw_uid == 0);
|
||||
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
setutmp(username, tty);
|
||||
#endif
|
||||
|
||||
if (*tty != '/')
|
||||
snprintf(full_tty, sizeof(full_tty)-1, "/dev/%s", tty);
|
||||
else
|
||||
safe_strncpy(full_tty, tty, sizeof(full_tty)-1);
|
||||
if (ENABLE_FEATURE_UTMP)
|
||||
write_utent(username);
|
||||
|
||||
#ifdef CONFIG_SELINUX
|
||||
if (is_selinux_enabled()) {
|
||||
@ -249,7 +218,7 @@ auth_ok:
|
||||
}
|
||||
}
|
||||
#endif
|
||||
if (!is_my_tty(full_tty))
|
||||
if (!is_my_tty())
|
||||
syslog(LOG_ERR, "unable to determine TTY name, got %s", full_tty);
|
||||
|
||||
/* Try these, but don't complain if they fail
|
||||
@ -300,96 +269,91 @@ auth_ok:
|
||||
}
|
||||
|
||||
|
||||
static int login_prompt(char *buf_name)
|
||||
static void get_username_or_die(char *buf, int size_buf)
|
||||
{
|
||||
char buf[1024];
|
||||
char *sp, *ep;
|
||||
int i;
|
||||
int c, cntdown;
|
||||
cntdown = EMPTY_USERNAME_COUNT;
|
||||
prompt:
|
||||
/* skip whitespace */
|
||||
print_login_prompt();
|
||||
do {
|
||||
c = getchar();
|
||||
if (c == EOF) exit(1);
|
||||
if (c == '\n') {
|
||||
if (!--cntdown) exit(1);
|
||||
goto prompt;
|
||||
}
|
||||
} while (isspace(c));
|
||||
|
||||
for (i=0; i<EMPTY_USERNAME_COUNT; i++) {
|
||||
print_login_prompt();
|
||||
|
||||
if (!fgets(buf, sizeof(buf)-1, stdin))
|
||||
return 0;
|
||||
|
||||
if (!strchr(buf, '\n'))
|
||||
return 0;
|
||||
|
||||
for (sp = buf; isspace(*sp); sp++) { }
|
||||
for (ep = sp; isgraph(*ep); ep++) { }
|
||||
|
||||
*ep = '\0';
|
||||
safe_strncpy(buf_name, sp, USERNAME_SIZE);
|
||||
if (buf_name[0])
|
||||
return 1;
|
||||
}
|
||||
return 0;
|
||||
*buf++ = c;
|
||||
if (!fgets(buf, size_buf-2, stdin))
|
||||
exit(1);
|
||||
if (!strchr(buf, '\n'))
|
||||
exit(1);
|
||||
while (isgraph(*buf)) buf++;
|
||||
*buf = '\0';
|
||||
}
|
||||
|
||||
|
||||
static int check_nologin(int amroot)
|
||||
static void die_if_nologin_and_non_root(int amroot)
|
||||
{
|
||||
if (access(bb_path_nologin_file, F_OK) == 0) {
|
||||
FILE *fp;
|
||||
int c;
|
||||
FILE *fp;
|
||||
int c;
|
||||
|
||||
fp = fopen(bb_path_nologin_file, "r");
|
||||
if (fp) {
|
||||
while ((c = getc(fp)) != EOF)
|
||||
putchar((c=='\n') ? '\r' : c);
|
||||
if (access(bb_path_nologin_file, F_OK))
|
||||
return;
|
||||
|
||||
fflush(stdout);
|
||||
fclose(fp);
|
||||
} else {
|
||||
puts("\r\nSystem closed for routine maintenance.\r");
|
||||
}
|
||||
if (!amroot)
|
||||
return 1;
|
||||
|
||||
puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
|
||||
}
|
||||
return 0;
|
||||
fp = fopen(bb_path_nologin_file, "r");
|
||||
if (fp) {
|
||||
while ((c = getc(fp)) != EOF)
|
||||
putchar((c=='\n') ? '\r' : c);
|
||||
fflush(stdout);
|
||||
fclose(fp);
|
||||
} else
|
||||
puts("\r\nSystem closed for routine maintenance\r");
|
||||
if (!amroot)
|
||||
exit(1);
|
||||
puts("\r\n[Disconnect bypassed -- root login allowed.]\r");
|
||||
}
|
||||
|
||||
#ifdef CONFIG_FEATURE_SECURETTY
|
||||
|
||||
static int check_tty(const char *tty)
|
||||
static int check_securetty(void)
|
||||
{
|
||||
FILE *fp;
|
||||
int i;
|
||||
char buf[BUFSIZ];
|
||||
|
||||
fp = fopen(bb_path_securetty_file, "r");
|
||||
if (fp) {
|
||||
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]=='\0') || (buf[0]=='#'))
|
||||
continue;
|
||||
|
||||
if (strcmp(buf, tty)== 0) {
|
||||
fclose(fp);
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
fclose(fp);
|
||||
return 0;
|
||||
if (!fp) {
|
||||
/* A missing securetty file is not an error. */
|
||||
return 1;
|
||||
}
|
||||
/* 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]=='\0') || (buf[0]=='#'))
|
||||
continue;
|
||||
if (strcmp(buf, short_tty) == 0) {
|
||||
fclose(fp);
|
||||
return 1;
|
||||
}
|
||||
}
|
||||
fclose(fp);
|
||||
return 0;
|
||||
}
|
||||
|
||||
#endif
|
||||
|
||||
/* returns 1 if true */
|
||||
static int is_my_tty(const char *tty)
|
||||
static int is_my_tty(void)
|
||||
{
|
||||
struct stat by_name, by_fd;
|
||||
|
||||
if (stat(tty, &by_name) || fstat(0, &by_fd))
|
||||
if (stat(full_tty, &by_name) || fstat(0, &by_fd))
|
||||
return 0;
|
||||
|
||||
if (by_name.st_rdev != by_fd.st_rdev)
|
||||
@ -414,15 +378,10 @@ static void motd(void)
|
||||
|
||||
|
||||
#ifdef CONFIG_FEATURE_UTMP
|
||||
// vv Taken from tinylogin utmp.c vv
|
||||
|
||||
#define NO_UTENT \
|
||||
"No utmp entry. You must exec \"login\" from the lowest level \"sh\""
|
||||
#define NO_TTY \
|
||||
"Unable to determine your tty name."
|
||||
/* vv Taken from tinylogin utmp.c vv */
|
||||
|
||||
/*
|
||||
* checkutmp - see if utmp file is correct for this process
|
||||
* 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.
|
||||
@ -435,9 +394,8 @@ static void motd(void)
|
||||
* command line flags.
|
||||
*/
|
||||
|
||||
static void checkutmp(int picky)
|
||||
static void read_or_build_utent(int picky)
|
||||
{
|
||||
char *line;
|
||||
struct utmp *ut;
|
||||
pid_t pid = getpid();
|
||||
|
||||
@ -446,53 +404,41 @@ static void checkutmp(int picky)
|
||||
/* 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))
|
||||
(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) {
|
||||
utent = *ut;
|
||||
} else {
|
||||
time_t t_tmp;
|
||||
|
||||
if (picky) {
|
||||
puts(NO_UTENT);
|
||||
exit(1);
|
||||
}
|
||||
line = ttyname(0);
|
||||
if (!line) {
|
||||
puts(NO_TTY);
|
||||
exit(1);
|
||||
}
|
||||
if (strncmp(line, "/dev/", 5) == 0)
|
||||
line += 5;
|
||||
if (picky)
|
||||
bb_error_msg_and_die("no utmp entry found");
|
||||
|
||||
memset(&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_line, short_tty, sizeof(utent.ut_line));
|
||||
/* This one is only 4 chars wide. Try to fit something
|
||||
* remotely meaningful by skipping "tty"... */
|
||||
strncpy(utent.ut_id, short_tty + 3, sizeof(utent.ut_id));
|
||||
strncpy(utent.ut_user, "LOGIN", sizeof(utent.ut_user));
|
||||
t_tmp = (time_t)utent.ut_time;
|
||||
time(&t_tmp);
|
||||
utent.ut_time = time(NULL);
|
||||
}
|
||||
}
|
||||
|
||||
/*
|
||||
* setutmp - put a USER_PROCESS entry in the utmp file
|
||||
* write_utent - put a USER_PROCESS entry in the utmp file
|
||||
*
|
||||
* setutmp changes the type of the current utmp entry to
|
||||
* write_utent changes the type of the current utmp entry to
|
||||
* USER_PROCESS. the wtmp file will be updated as well.
|
||||
*/
|
||||
|
||||
static void setutmp(const char *name, const char *line ATTRIBUTE_UNUSED)
|
||||
static void write_utent(const char *username)
|
||||
{
|
||||
time_t t_tmp = (time_t)utent.ut_time;
|
||||
|
||||
utent.ut_type = USER_PROCESS;
|
||||
strncpy(utent.ut_user, name, sizeof(utent.ut_user));
|
||||
time(&t_tmp);
|
||||
/* other fields already filled in by checkutmp above */
|
||||
strncpy(utent.ut_user, username, sizeof(utent.ut_user));
|
||||
utent.ut_time = time(NULL);
|
||||
/* other fields already filled in by read_or_build_utent above */
|
||||
setutent();
|
||||
pututline(&utent);
|
||||
endutent();
|
||||
|
Loading…
Reference in New Issue
Block a user