emo/shadow
1
0
Fork 0
Code Issues Pull Requests Packages Releases Activity

* src/su.c (save_caller_context): Extract from main() the code

Browse Source 
used to save the caller's context.
This commit is contained in:
nekral-guest 2011-06-13 18:26:47 +00:00
parent b661b913b5
commit 6be3ac560b
2 changed files with 118 additions and 94 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
ChangeLog
View File

@ -1,3 +1,8 @@
2011-06-12 Nicolas François <nicolas.francois@centraliens.net>
* src/su.c (save_caller_context): Extract from main() the code
used to save the caller's context.
2011-06-10 Nicolas François <nicolas.francois@centraliens.net>
* src/su.c: Group some of the environment processing blocks. The

207
src/su.c
View File

@ -75,10 +75,20 @@
* Global variables
*/
const char *Prog;
const char *caller_tty = NULL; /* Name of tty SU is run from */
bool caller_is_root = false;
uid_t caller_uid;
#ifndef USE_PAM
int caller_on_console = 0;
#ifdef SU_ACCESS
char *caller_pass;
#endif
#endif /* !USE_PAM */
/* not needed by sulog.c anymore */
static char name[BUFSIZ];
static char oldname[BUFSIZ];
static char caller_name[BUFSIZ];
/* If nonzero, change some environment vars to indicate the user su'd to. */
static bool change_environment;
@ -110,6 +120,7 @@ static RETSIGTYPE die (int);
static bool iswheel (const char *);
#endif /* !USE_PAM */
static struct passwd * check_perms (void);
static void save_caller_context (char **argv);
#ifndef USE_PAM
/*
@ -178,12 +189,12 @@ static bool restricted_shell (const char *shellstr)
static void su_failure (const char *tty, bool su_to_root)
{
sulog (tty, false, oldname, name); /* log failed attempt */
sulog (tty, false, caller_name, name); /* log failed attempt */
#ifdef USE_SYSLOG
if (getdef_bool ("SYSLOG_SU_ENAB")) {
SYSLOG ((su_to_root ? LOG_NOTICE : LOG_INFO,
"- %s %s:%s", tty,
('\0' != oldname[0]) ? oldname : "???",
('\0' != caller_name[0]) ? caller_name : "???",
('\0' != name[0]) ? name : "???"));
}
closelog ();
@ -440,10 +451,10 @@ static struct passwd * check_perms (void)
* to Chris Evans <lady0110@sable.ox.ac.uk>.
*/
if (!amroot) {
if (!caller_is_root) {
if ( (0 == pw->pw_uid)
&& getdef_bool ("SU_WHEEL_ONLY")
&& !iswheel (oldname)) {
&& !iswheel (caller_name)) {
fprintf (stderr,
_("You are not authorized to su %s\n"),
name);
@ -457,7 +468,7 @@ static struct passwd * check_perms (void)
}
}
switch (check_su_auth (oldname, name, 0 == pw->pw_uid)) {
switch (check_su_auth (caller_name, name, 0 == pw->pw_uid)) {
case 0: /* normal su, require target user's password */
break;
case 1: /* require no password */
@ -465,7 +476,7 @@ static struct passwd * check_perms (void)
break;
case 2: /* require own password */
puts (_("(Enter your own password)"));
pw->pw_passwd = oldpass;
pw->pw_passwd = caller_pass;
break;
default: /* access denied (-1) or unexpected value */
fprintf (stderr,
@ -486,12 +497,12 @@ static struct passwd * check_perms (void)
pam_strerror (pamh, ret)));
fprintf (stderr, _("%s: %s\n"), Prog, pam_strerror (pamh, ret));
(void) pam_end (pamh, ret);
su_failure (tty, 0 == pw->pw_uid);
su_failure (caller_tty, 0 == pw->pw_uid);
}
ret = pam_acct_mgmt (pamh, 0);
if (PAM_SUCCESS != ret) {
if (amroot) {
if (caller_is_root) {
fprintf (stderr,
_("%s: %s\n(Ignored)\n"),
Prog, pam_strerror (pamh, ret));
@ -504,7 +515,7 @@ static struct passwd * check_perms (void)
_("%s: %s\n"),
Prog, pam_strerror (pamh, ret));
(void) pam_end (pamh, ret);
su_failure (tty, 0 == pw->pw_uid);
su_failure (caller_tty, 0 == pw->pw_uid);
}
} else {
SYSLOG ((LOG_ERR, "pam_acct_mgmt: %s",
@ -513,7 +524,7 @@ static struct passwd * check_perms (void)
_("%s: %s\n"),
Prog, pam_strerror (pamh, ret));
(void) pam_end (pamh, ret);
su_failure (tty, 0 == pw->pw_uid);
su_failure (caller_tty, 0 == pw->pw_uid);
}
}
#else /* !USE_PAM */
@ -528,12 +539,12 @@ static struct passwd * check_perms (void)
* The first character of an administrator defined method is an '@'
* character.
*/
if ( !amroot
if ( !caller_is_root
&& (pw_auth (pw->pw_passwd, name, PW_SU, (char *) 0) != 0)) {
SYSLOG (((pw->pw_uid != 0)? LOG_NOTICE : LOG_WARN,
"Authentication failed for %s", name));
fprintf(stderr, _("%s: Authentication failure\n"), Prog);
su_failure (tty, 0 == pw->pw_uid);
su_failure (caller_tty, 0 == pw->pw_uid);
}
(void) signal (SIGQUIT, oldsig);
@ -542,7 +553,7 @@ static struct passwd * check_perms (void)
* expired accounts, but normal users can't become a user with an
* expired password.
*/
if ((!amroot) && (NULL != spwd)) {
if ((!caller_is_root) && (NULL != spwd)) {
(void) expire (pw, spwd);
}
@ -552,15 +563,15 @@ static struct passwd * check_perms (void)
* there is a "SU" entry in the /etc/porttime file denying access to
* the account.
*/
if (!amroot) {
if (!caller_is_root) {
if (!isttytime (name, "SU", time ((time_t *) 0))) {
SYSLOG (((0 != pw->pw_uid) ? LOG_WARN : LOG_CRIT,
"SU by %s to restricted account %s",
oldname, name));
caller_name, name));
fprintf (stderr,
_("%s: You are not authorized to su at that time\n"),
Prog);
su_failure (tty, 0 == pw->pw_uid);
su_failure (caller_tty, 0 == pw->pw_uid);
}
}
#endif /* !USE_PAM */
@ -583,6 +594,80 @@ static struct passwd * check_perms (void)
return pw;
}
/*
* save_caller_context - save information from the call context
*
* Save the program's name (Prog), caller's UID (caller_uid /
* caller_is_root), name (caller_name), and password (caller_pass),
* the TTY (ttyp), and whether su was called from a console
* (is_console) for further processing and before they might change.
*/
static void save_caller_context (char **argv)
{
struct passwd *pw = NULL;
/*
* Get the program name. The program name is used as a prefix to
* most error messages.
*/
Prog = Basename (argv[0]);
caller_uid = getuid ();
caller_is_root = (caller_uid == 0);
/*
* Get the tty name. Entries will be logged indicating that the user
* tried to change to the named new user from the current terminal.
*/
caller_tty = ttyname (0);
if ((isatty (0) != 0) && (NULL != caller_tty)) {
#ifndef USE_PAM
caller_on_console = console (caller_tty);
#endif
} else {
/*
* Be more paranoid, like su from SimplePAMApps. --marekm
*/
if (!caller_is_root) {
fprintf (stderr,
_("%s: must be run from a terminal\n"),
Prog);
exit (1);
}
caller_tty = "???";
}
/*
* Get the user's real name. The current UID is used to determine
* who has executed su. That user ID must exist.
*/
pw = get_my_pwent ();
if (NULL == pw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
(unsigned long) caller_uid));
su_failure (caller_tty, true); // FIXME: at this time I do not know the target UID
}
STRFCPY (caller_name, pw->pw_name);
#ifndef USE_PAM
#ifdef SU_ACCESS
/*
* Sort out the password of user calling su, in case needed later
* -- chris
*/
if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
struct spwd *spwd = getspnam (caller_name);
if (NULL != spwd) {
pw->pw_passwd = spwd->sp_pwdp;
}
}
caller_pass = xstrdup (pw->pw_passwd);
#endif /* SU_ACCESS */
#endif /* !USE_PAM */
}
/*
* su - switch user id
*
@ -596,11 +681,8 @@ static struct passwd * check_perms (void)
int main (int argc, char **argv)
{
const char *cp;
const char *tty = NULL; /* Name of tty SU is run from */
bool doshell = false;
bool fakelogin = false;
bool amroot = false;
uid_t my_uid;
struct passwd *pw = NULL;
char *shellstr = NULL;
char *command = NULL;
@ -611,11 +693,7 @@ int main (int argc, char **argv)
int err = 0;
RETSIGTYPE (*oldsig) (int);
int is_console = 0;
#ifdef SU_ACCESS
char *oldpass;
#endif
#endif /* !USE_PAM */
(void) setlocale (LC_ALL, "");
@ -624,11 +702,7 @@ int main (int argc, char **argv)
change_environment = true;
/*
* Get the program name. The program name is used as a prefix to
* most error messages.
*/
Prog = Basename (argv[0]);
save_caller_context (argv);
OPENLOG ("su");
@ -692,31 +766,6 @@ int main (int argc, char **argv)
initenv ();
my_uid = getuid ();
amroot = (my_uid == 0);
/*
* Get the tty name. Entries will be logged indicating that the user
* tried to change to the named new user from the current terminal.
*/
tty = ttyname (0);
if ((isatty (0) != 0) && (NULL != tty)) {
#ifndef USE_PAM
is_console = console (tty);
#endif
} else {
/*
* Be more paranoid, like su from SimplePAMApps. --marekm
*/
if (!amroot) {
fprintf (stderr,
_("%s: must be run from a terminal\n"),
Prog);
exit (1);
}
tty = "???";
}
/*
* The next argument must be either a user ID, or some flag to a
* subshell. Pretty sticky since you can't have an argument which
@ -737,7 +786,7 @@ int main (int argc, char **argv)
root_pw = getpwuid (0);
if (NULL == root_pw) {
SYSLOG ((LOG_CRIT, "There is no UID 0 user."));
su_failure (tty, true);
su_failure (caller_tty, true);
}
(void) strcpy (name, root_pw->pw_name);
}
@ -748,37 +797,7 @@ int main (int argc, char **argv)
doshell = false;
}
/*
* Get the user's real name. The current UID is used to determine
* who has executed su. That user ID must exist.
*/
pw = get_my_pwent ();
if (NULL == pw) {
fprintf (stderr,
_("%s: Cannot determine your user name.\n"),
Prog);
SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
(unsigned long) my_uid));
su_failure (tty, true); // FIXME: at this time I do not know the target UID
}
STRFCPY (oldname, pw->pw_name);
#ifndef USE_PAM
#ifdef SU_ACCESS
/*
* Sort out the password of user calling su, in case needed later
* -- chris
*/
if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
struct spwd *spwd = getspnam (oldname);
if (NULL != spwd) {
pw->pw_passwd = spwd->sp_pwdp;
}
}
oldpass = xstrdup (pw->pw_passwd);
#endif /* SU_ACCESS */
#else /* USE_PAM */
#ifdef USE_PAM
ret = pam_start ("su", name, &conv, &pamh);
if (PAM_SUCCESS != ret) {
SYSLOG ((LOG_ERR, "pam_start: error %d", ret);
@ -788,9 +807,9 @@ int main (int argc, char **argv)
exit (1);
}
ret = pam_set_item (pamh, PAM_TTY, (const void *) tty);
ret = pam_set_item (pamh, PAM_TTY, (const void *) caller_tty);
if (PAM_SUCCESS == ret) {
ret = pam_set_item (pamh, PAM_RUSER, (const void *) oldname);
ret = pam_set_item (pamh, PAM_RUSER, (const void *) caller_name);
}
if (PAM_SUCCESS != ret) {
SYSLOG ((LOG_ERR, "pam_set_item: %s",
@ -815,7 +834,7 @@ int main (int argc, char **argv)
* restricted shell, the environment must be changed and the shell
* must be the one specified in /etc/passwd.
*/
if ( !amroot
if ( !caller_is_root
&& restricted_shell (pw->pw_shell)) {
shellstr = NULL;
change_environment = true;
@ -910,13 +929,13 @@ int main (int argc, char **argv)
addenv ("IFS= \t\n", NULL); /* ... instead, set a safe IFS */
}
sulog (tty, true, oldname, name); /* save SU information */
sulog (caller_tty, true, caller_name, name); /* save SU information */
endpwent ();
endspent ();
#ifdef USE_SYSLOG
if (getdef_bool ("SYSLOG_SU_ENAB")) {
SYSLOG ((LOG_INFO, "+ %s %s:%s", tty,
('\0' != oldname[0]) ? oldname : "???",
SYSLOG ((LOG_INFO, "+ %s %s:%s", caller_tty,
('\0' != caller_name[0]) ? caller_name : "???",
('\0' != name[0]) ? name : "???"));
}
#endif
@ -978,11 +997,11 @@ int main (int argc, char **argv)
environ = newenvp; /* make new environment active */
/* no limits if su from root (unless su must fake login's behavior) */
if (!amroot || fakelogin) {
if (!caller_is_root || fakelogin) {
setup_limits (pw);
}
if (setup_uid_gid (pw, is_console) != 0) {
if (setup_uid_gid (pw, caller_on_console) != 0) {
exit (1);
}
#endif /* !USE_PAM */