From 6be3ac560b805bafbc1ec40f75307d2cd98b6e58 Mon Sep 17 00:00:00 2001 From: nekral-guest Date: Mon, 13 Jun 2011 18:26:47 +0000 Subject: [PATCH] * src/su.c (save_caller_context): Extract from main() the code used to save the caller's context. --- ChangeLog | 5 ++ src/su.c | 207 +++++++++++++++++++++++++++++------------------------- 2 files changed, 118 insertions(+), 94 deletions(-) diff --git a/ChangeLog b/ChangeLog index 42380db2..bd65beb8 100644 --- a/ChangeLog +++ b/ChangeLog @@ -1,3 +1,8 @@ +2011-06-12 Nicolas François + + * src/su.c (save_caller_context): Extract from main() the code + used to save the caller's context. + 2011-06-10 Nicolas François * src/su.c: Group some of the environment processing blocks. The diff --git a/src/su.c b/src/su.c index 7d6e3704..fc473c6c 100644 --- a/src/su.c +++ b/src/su.c @@ -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 . */ - 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 */