* lib/prototypes.h, src/suauth.c, src/su.c (check_su_auth): Do not

	use the pwent global variable to communicate between APIs of
	different files. Added boolean parameter su_to_root to
	check_su_auth().
	* src/su.c (check_perms): Return the passwd entry of the finally
	authenticated user. Remove usage of the pwent variable.
	* src/su.c: The password of the caller is the one from the
	spwd structure only if the passwd's password is 'x'.

diff --git a/ChangeLog b/ChangeLog
index 6fc552d5b3135a045b7821e5133c00b8d340ccae..1871ff096731dfa358c429f5d65f28a7270f3cfa 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -17,6 +17,14 @@
        restricted_shell is called only once. This will allow moving the
        environment definition after the switch to the new user.
        * src/su.c: Extract the authentication from the main function.
+       * lib/prototypes.h, src/suauth.c, src/su.c (check_su_auth): Do not
+       use the pwent global variable to communicate between APIs of
+       different files. Added boolean parameter su_to_root to
+       check_su_auth().
+       * src/su.c (check_perms): Return the passwd entry of the finally
+       authenticated user. Remove usage of the pwent variable.
+       * src/su.c: The password of the caller is the one from the
+       spwd structure only if the passwd's password is 'x'.
 
 2011-06-10  Nicolas François  <nicolas.francois@centraliens.net>
 

diff --git a/lib/prototypes.h b/lib/prototypes.h
index a8993268a840311fb22f74c6bf696fc0793c335d..344d30fd6ae822f1c56b9f412f324415164bf4f1 100644 (file)
--- a/lib/prototypes.h
+++ b/lib/prototypes.h
@@ -348,7 +348,9 @@ extern int safe_system (const char *command,
 extern long strtoday (const char *);
 
 /* suauth.c */
-extern int check_su_auth (const char *actual_id, const char *wanted_id);
+extern int check_su_auth (const char *actual_id,
+                          const char *wanted_id,
+                          bool su_to_root);
 
 /* sulog.c */
 extern void sulog (const char *tty,

diff --git a/src/su.c b/src/su.c
index 8938533f5d08bf03828b25d8356da0dd9938c4fe..e3b9d5eca0df1b6d54c708ac30716301571ed82f 100644 (file)
--- a/src/su.c
+++ b/src/su.c
@@ -93,8 +93,6 @@ static int caught = 0;
 static pid_t pid_child = 0;
 #endif
 
-extern struct passwd pwent;
-
 /*
  * External identifiers
  */
@@ -114,7 +112,7 @@ static RETSIGTYPE kill_child (int unused(s));
 static RETSIGTYPE die (int);
 static bool iswheel (const char *);
 #endif                         /* !USE_PAM */
-static void check_perms (void);
+static struct passwd * check_perms (void);
 
 #ifndef USE_PAM
 /*
@@ -181,12 +179,12 @@ static bool restricted_shell (const char *shellstr)
        return true;
 }
 
-static void su_failure (const char *tty)
+static void su_failure (const char *tty, bool su_to_root)
 {
        sulog (tty, false, oldname, name);      /* log failed attempt */
 #ifdef USE_SYSLOG
        if (getdef_bool ("SYSLOG_SU_ENAB")) {
-               SYSLOG (((0 != pwent.pw_uid) ? LOG_INFO : LOG_NOTICE,
+               SYSLOG ((su_to_root ? LOG_NOTICE : LOG_INFO,
                         "- %s %s:%s", tty,
                         ('\0' != oldname[0]) ? oldname : "???",
                         ('\0' != name[0]) ? name : "???"));
@@ -413,28 +411,18 @@ static void usage (int status)
  *     In case of subsystem login, the user is first authenticated in the
  *     caller's root subsystem, and then in the user's target subsystem.
  */
-static void check_perms (void)
+static struct passwd * check_perms (void)
 {
        /*
         * The password file entries for the user is gotten and the account
         * validated.
         */
-       pw = xgetpwnam (name);
+       struct passwd *pw = xgetpwnam (name);
        if (NULL == pw) {
                (void) fprintf (stderr, _("Unknown id: %s\n"), name);
                closelog ();
                exit (1);
        }
-#ifndef USE_PAM
-       spwd = NULL;
-       if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
-               spwd = getspnam (name); /* !USE_PAM, no need for xgetspnam */
-               if (NULL != spwd) {
-                       pw->pw_passwd = spwd->sp_pwdp;
-               }
-       }
-#endif                         /* !USE_PAM */
-       pwent = *pw;
 
 #ifndef USE_PAM
        /*
@@ -456,7 +444,7 @@ static void check_perms (void)
         */
 
        if (!amroot) {
-               if (   (0 == pwent.pw_uid)
+               if (   (0 == pw->pw_uid)
                    && getdef_bool ("SU_WHEEL_ONLY")
                    && !iswheel (oldname)) {
                        fprintf (stderr,
@@ -465,15 +453,22 @@ static void check_perms (void)
                        exit (1);
                }
 #ifdef SU_ACCESS
-               switch (check_su_auth (oldname, name)) {
+               spwd = getspnam (name); /* !USE_PAM, no need for xgetspnam */
+               if (strcmp (pw->pw_passwd, SHADOW_PASSWD_STRING) == 0) {
+                       if (NULL != spwd) {
+                               pw->pw_passwd = spwd->sp_pwdp;
+                       }
+               }
+
+               switch (check_su_auth (oldname, name, 0 == pw->pw_uid)) {
                case 0: /* normal su, require target user's password */
                        break;
                case 1: /* require no password */
-                       pwent.pw_passwd = "";   /* XXX warning: const */
+                       pw->pw_passwd = "";     /* XXX warning: const */
                        break;
                case 2: /* require own password */
                        puts (_("(Enter your own password)"));
-                       pwent.pw_passwd = oldpass;
+                       pw->pw_passwd = oldpass;
                        break;
                default:        /* access denied (-1) or unexpected value */
                        fprintf (stderr,
@@ -494,7 +489,7 @@ static void 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);
+               su_failure (tty, 0 == pw->pw_uid);
        }
 
        ret = pam_acct_mgmt (pamh, 0);
@@ -512,7 +507,7 @@ static void check_perms (void)
                                         _("%s: %s\n"),
                                         Prog, pam_strerror (pamh, ret));
                                (void) pam_end (pamh, ret);
-                               su_failure (tty);
+                               su_failure (tty, 0 == pw->pw_uid);
                        }
                } else {
                        SYSLOG ((LOG_ERR, "pam_acct_mgmt: %s",
@@ -521,7 +516,7 @@ static void check_perms (void)
                                 _("%s: %s\n"),
                                 Prog, pam_strerror (pamh, ret));
                        (void) pam_end (pamh, ret);
-                       su_failure (tty);
+                       su_failure (tty, 0 == pw->pw_uid);
                }
        }
 #else                          /* !USE_PAM */
@@ -537,11 +532,11 @@ static void check_perms (void)
         * character.
         */
        if (   !amroot
-           && (pw_auth (pwent.pw_passwd, name, PW_SU, (char *) 0) != 0)) {
-               SYSLOG (((pwent.pw_uid != 0)? LOG_NOTICE : LOG_WARN,
+           && (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);
+               su_failure (tty, 0 == pw->pw_uid);
        }
        (void) signal (SIGQUIT, oldsig);
 
@@ -551,7 +546,7 @@ static void check_perms (void)
         * expired password.
         */
        if ((!amroot) && (NULL != spwd)) {
-               (void) expire (&pwent, spwd);
+               (void) expire (pw, spwd);
        }
 
        /*
@@ -561,14 +556,14 @@ static void check_perms (void)
         * the account.
         */
        if (!amroot) {
-               if (!isttytime (pwent.pw_name, "SU", time ((time_t *) 0))) {
-                       SYSLOG (((0 != pwent.pw_uid) ? LOG_WARN : LOG_CRIT,
+               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));
                        fprintf (stderr,
                                 _("%s: You are not authorized to su at that time\n"),
                                 Prog);
-                       su_failure (tty);
+                       su_failure (tty, 0 == pw->pw_uid);
                }
        }
 #endif                         /* !USE_PAM */
@@ -581,13 +576,14 @@ static void check_perms (void)
         * the shell specified in /etc/passwd (not the one specified with
         * --shell, which will be the one executed in the chroot later).
         */
-       if ('*' == pwent.pw_shell[0]) { /* subsystem root required */
-               subsystem (&pwent);     /* change to the subsystem root */
+       if ('*' == pw->pw_shell[0]) {   /* subsystem root required */
+               subsystem (pw); /* change to the subsystem root */
                endpwent ();            /* close the old password databases */
                endspent ();
                return check_perms ();  /* authenticate in the subsystem */
        }
 
+       return pw;
 }
 
 /*
@@ -622,8 +618,6 @@ int main (int argc, char **argv)
        RETSIGTYPE (*oldsig) (int);
        int is_console = 0;
 
-       struct spwd *spwd = 0;
-
 #ifdef SU_ACCESS
        char *oldpass;
 #endif
@@ -748,7 +742,7 @@ 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);
+                               su_failure (tty, true);
                        }
                        (void) strcpy (name, root_pw->pw_name);
                }
@@ -770,7 +764,7 @@ int main (int argc, char **argv)
                         Prog);
                SYSLOG ((LOG_WARN, "Cannot determine the user name of the caller (UID %lu)",
                         (unsigned long) my_uid));
-               su_failure (tty);
+               su_failure (tty, true); // FIXME: at this time I do not know the target UID
        }
        STRFCPY (oldname, pw->pw_name);
 
@@ -780,9 +774,11 @@ int main (int argc, char **argv)
         * Sort out the password of user calling su, in case needed later
         * -- chris
         */
-       spwd = getspnam (oldname); /* !USE_PAM, no need for xgetspnam */
-       if (NULL != spwd) {
-               pw->pw_passwd = spwd->sp_pwdp;
+       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 */
@@ -810,7 +806,7 @@ int main (int argc, char **argv)
        }
 #endif                         /* USE_PAM */
 
-       check_perms ();
+       pw = check_perms ();
 
        /* If the user do not want to change the environment,
         * use the current SHELL.
@@ -825,7 +821,7 @@ int main (int argc, char **argv)
         * must be the one specified in /etc/passwd.
         */
        if (   !amroot
-           && restricted_shell (pwent.pw_shell)) {
+           && restricted_shell (pw->pw_shell)) {
                shellstr = NULL;
                change_environment = true;
        }
@@ -834,7 +830,7 @@ int main (int argc, char **argv)
         * in /etc/passwd.
         */
        if (NULL == shellstr) {
-               shellstr = (char *) strdup (pwent.pw_shell);
+               shellstr = (char *) strdup (pw->pw_shell);
        }
 
        /*
@@ -905,9 +901,9 @@ int main (int argc, char **argv)
                }
        }
 
-       cp = getdef_str ((pwent.pw_uid == 0) ? "ENV_SUPATH" : "ENV_PATH");
+       cp = getdef_str ((pw->pw_uid == 0) ? "ENV_SUPATH" : "ENV_PATH");
        if (NULL == cp) {
-               addenv ((pwent.pw_uid == 0) ? "PATH=/sbin:/bin:/usr/sbin:/usr/bin" : "PATH=/bin:/usr/bin", NULL);
+               addenv ((pw->pw_uid == 0) ? "PATH=/sbin:/bin:/usr/sbin:/usr/bin" : "PATH=/bin:/usr/bin", NULL);
        } else if (strchr (cp, '=') != NULL) {
                addenv (cp, NULL);
        } else {
@@ -931,7 +927,7 @@ int main (int argc, char **argv)
 
 #ifdef USE_PAM
        /* set primary group id and supplementary groups */
-       if (setup_groups (&pwent) != 0) {
+       if (setup_groups (pw) != 0) {
                pam_end (pamh, PAM_ABORT);
                exit (1);
        }
@@ -976,7 +972,7 @@ int main (int argc, char **argv)
        }
 
        /* become the new user */
-       if (change_uid (&pwent) != 0) {
+       if (change_uid (pw) != 0) {
                pam_close_session (pamh, 0);
                pam_setcred (pamh, PAM_DELETE_CRED);
                (void) pam_end (pamh, PAM_ABORT);
@@ -987,22 +983,22 @@ int main (int argc, char **argv)
 
        /* no limits if su from root (unless su must fake login's behavior) */
        if (!amroot || fakelogin) {
-               setup_limits (&pwent);
+               setup_limits (pw);
        }
 
-       if (setup_uid_gid (&pwent, is_console) != 0) {
+       if (setup_uid_gid (pw, is_console) != 0) {
                exit (1);
        }
 #endif                         /* !USE_PAM */
 
        if (change_environment) {
                if (fakelogin) {
-                       pwent.pw_shell = shellstr;
-                       setup_env (&pwent);
+                       pw->pw_shell = shellstr;
+                       setup_env (pw);
                } else {
-                       addenv ("HOME", pwent.pw_dir);
-                       addenv ("USER", pwent.pw_name);
-                       addenv ("LOGNAME", pwent.pw_name);
+                       addenv ("HOME", pw->pw_dir);
+                       addenv ("USER", pw->pw_name);
+                       addenv ("LOGNAME", pw->pw_name);
                        addenv ("SHELL", shellstr);
                }
        }

diff --git a/src/suauth.c b/src/suauth.c
index a2c6735ab3f90b39c6dda29cc657e6c4e831f896..a5bbe4c4267e7cd3aaa75246e2ea39b4219bd315 100644 (file)
--- a/src/suauth.c
+++ b/src/suauth.c
@@ -48,11 +48,6 @@
 #define        DENY            -1
 #define        OWNPWORD        2
 
-/*
- * Global variables
- */
-struct passwd pwent;
-
 #ifdef SU_ACCESS
 
 /* Really, I could do with a few const char's here defining all the 
@@ -65,7 +60,9 @@ static int isgrp (const char *, const char *);
 static int lines = 0;
 
 
-int check_su_auth (const char *actual_id, const char *wanted_id)
+int check_su_auth (const char *actual_id,
+                   const char *wanted_id,
+                   bool su_to_root)
 {
        int posn, endline;
        const char field[] = ":";
@@ -131,7 +128,7 @@ int check_su_auth (const char *actual_id, const char *wanted_id)
                if (!applies (actual_id, from_users))
                        continue;
                if (!strcmp (action, "DENY")) {
-                       SYSLOG ((pwent.pw_uid ? LOG_NOTICE : LOG_WARN,
+                       SYSLOG ((su_to_root ? LOG_WARN : LOG_NOTICE,
                                 "DENIED su from '%s' to '%s' (%s)\n",
                                 actual_id, wanted_id, SUAUTHFILE));
                        fputs (_("Access to su to that account DENIED.\n"),
@@ -139,14 +136,14 @@ int check_su_auth (const char *actual_id, const char *wanted_id)
                        fclose (authfile_fd);
                        return DENY;
                } else if (!strcmp (action, "NOPASS")) {
-                       SYSLOG ((pwent.pw_uid ? LOG_INFO : LOG_NOTICE,
+                       SYSLOG ((su_to_root ? LOG_NOTICE : LOG_INFO,
                                 "NO password asked for su from '%s' to '%s' (%s)\n",
                                 actual_id, wanted_id, SUAUTHFILE));
                        fputs (_("Password authentication bypassed.\n"),stderr);
                        fclose (authfile_fd);
                        return NOPWORD;
                } else if (!strcmp (action, "OWNPASS")) {
-                       SYSLOG ((pwent.pw_uid ? LOG_INFO : LOG_NOTICE,
+                       SYSLOG ((su_to_root ? LOG_NOTICE : LOG_INFO,
                                 "su from '%s' to '%s': asking for user's own password (%s)\n",
                                 actual_id, wanted_id, SUAUTHFILE));
                        fputs (_("Please enter your OWN password as authentication.\n"),