su: remove program (util-linux is now the best source for it)

* README: Omit "su" from list of programs.
* src/su.c: Remove file.
* src/Makefile.am: Remove su-related rules and variables.
* tests/misc/su-fail: Remove test.
* tests/Makefile.am (TESTS): Remove misc/su-fail.
* tests/misc/invalid-opt: Remove su-related code.
* src/.gitignore: Remove su.
* man/su.x: Remove file.
* man/Makefile.am (su.1): Remove rule.
* po/POTFILES.in: Remove su.c from the list.
* TODO: Remove ancient entry.
* NEWS (Changes in behavior): Mention it.
* doc/coreutils.texi: Remove su-related description.
* AUTHORS: Remove su.
* m4/lib-check.m4 (cu_LIB_CHECK): Remove file/macro.
* configure.ac: Remove su-related code and sole use of cu_LIB_CHECK.
* scripts/git-hooks/commit-msg: Remove su from this list, too.

3 files changed, 2 insertions, 582 deletions

diff --git a/src/.gitignore b/src/.gitignore
index 9c4c9b717..d78178ce8 100644
--- a/src/.gitignore
+++ b/src/.gitignore
@@ -87,7 +87,6 @@ split
 stat
 stdbuf
 stty
-su
 sum
 sync
 tac
diff --git a/src/Makefile.am b/src/Makefile.am
index 06ab61527..309950559 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -21,7 +21,7 @@
 # Hence, if you want to install programs from this list anyway, say A and B,
 # use --enable-install-program=A,B
 no_install__progs = \
-  arch hostname su
+  arch hostname
 
 build_if_possible__progs = \
   chroot	\
@@ -32,7 +32,6 @@ build_if_possible__progs = \
   pinky		\
   stdbuf	\
   stty		\
-  su		\
   uptime	\
   users		\
   who
@@ -164,7 +163,7 @@ noinst_HEADERS =	\
 EXTRA_DIST = dcgen dircolors.hin tac-pipe.c \
   wheel-gen.pl extract-magic c99-to-c89.diff
 BUILT_SOURCES =
-CLEANFILES = $(SCRIPTS) su
+CLEANFILES = $(SCRIPTS)
 
 # Also remove these sometimes-built programs.
 # For example, even when excluded, they're built via _sc_check-AUTHORS.
@@ -268,7 +267,6 @@ split_LDADD = $(LDADD)
 stat_LDADD = $(LDADD)
 stdbuf_LDADD = $(LDADD)
 stty_LDADD = $(LDADD)
-su_LDADD = $(LDADD)
 sum_LDADD = $(LDADD)
 sync_LDADD = $(LDADD)
 tac_LDADD = $(LDADD)
@@ -357,9 +355,6 @@ factor_LDADD += $(LIB_GMP)
 # for getloadavg
 uptime_LDADD += $(GETLOADAVG_LIBS)
 
-# for crypt
-su_LDADD += $(LIB_CRYPT)
-
 # for various ACL functions
 copy_LDADD += $(LIB_ACL)
 ls_LDADD += $(LIB_ACL)
@@ -402,60 +397,6 @@ RELEASE_YEAR = \
   `sed -n '/.*COPYRIGHT_YEAR = \([0-9][0-9][0-9][0-9]\) };/s//\1/p' \
     $(top_srcdir)/lib/version-etc.c`
 
-all-local: su$(EXEEXT)
-
-installed_su = $(DESTDIR)$(bindir)/`echo su|sed '$(transform)'`
-
-setuid_root_mode = a=rx,u+s
-
-install_su =						\
-  if test "$(INSTALL_SU)" = yes; then			\
-    p=su;						\
-    echo " $(INSTALL_PROGRAM) $$p $(installed_su)";	\
-    $(INSTALL_PROGRAM) $$p $(installed_su);		\
-    echo " chown root $(installed_su)";			\
-    chown root $(installed_su);				\
-    echo " chmod $(setuid_root_mode) $(installed_su)";	\
-    chmod $(setuid_root_mode) $(installed_su);		\
-  else							\
-    :;							\
-  fi
-
-install-root: su$(EXEEXT)
-	@$(install_su)
-
-install-exec-hook: su$(EXEEXT)
-	@if test "$(INSTALL_SU)" = yes; then			\
-	  TMPFILE=$(DESTDIR)$(bindir)/.su-$$$$;			\
-	  rm -f $$TMPFILE;					\
-	  echo > $$TMPFILE;					\
-## See if we can create a setuid root executable in $(bindir).
-## If not, then don't even try to install su.
-	  can_create_suid_root_executable=no;			\
-	  chown root $$TMPFILE > /dev/null 2>&1			\
-	    && chmod $(setuid_root_mode) $$TMPFILE > /dev/null 2>&1 \
-	    && can_create_suid_root_executable=yes;		\
-	  rm -f $$TMPFILE;					\
-	  if test $$can_create_suid_root_executable = yes; then \
-	    $(install_su);					\
-	  else							\
-	    echo "WARNING: insufficient access; not installing su"; \
-	    echo "NOTE: to install su, run 'make install-root' as root"; \
-	    rm -f $(installed_su);				\
-	  fi;							\
-	else :;							\
-	fi
-
-uninstall-local:
-# Remove su only if it's one we installed.
-	@if test "$(INSTALL_SU)" = yes; then			\
-	  if grep '$(PACKAGE_NAME)' $(installed_su) > /dev/null 2>&1; then \
-	    echo "  rm -f $(installed_su)"; \
-	    rm -f $(installed_su); \
-	  else :; \
-	  fi; \
-	fi
-
 copy_sources = copy.c cp-hash.c extent-scan.c extent-scan.h
 
 # Use 'ginstall' in the definition of PROGRAMS and in dependencies to avoid
diff --git a/src/su.c b/src/su.c
deleted file mode 100644
index bb54cc33a..000000000
--- a/src/su.c
+++ /dev/null
@@ -1,520 +0,0 @@
-/* su for GNU.  Run a shell with substitute user and group IDs.
-   Copyright (C) 1992-2012 Free Software Foundation, Inc.
-
-   This program is free software: you can redistribute it and/or modify
-   it under the terms of the GNU General Public License as published by
-   the Free Software Foundation, either version 3 of the License, or
-   (at your option) any later version.
-
-   This program is distributed in the hope that it will be useful,
-   but WITHOUT ANY WARRANTY; without even the implied warranty of
-   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-   GNU General Public License for more details.
-
-   You should have received a copy of the GNU General Public License
-   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
-
-/* Run a shell with the real and effective UID and GID and groups
-   of USER, default 'root'.
-
-   The shell run is taken from USER's password entry, /bin/sh if
-   none is specified there.  If the account has a password, su
-   prompts for a password unless run by a user with real UID 0.
-
-   Does not change the current directory.
-   Sets 'HOME' and 'SHELL' from the password entry for USER, and if
-   USER is not root, sets 'USER' and 'LOGNAME' to USER.
-   The subshell is not a login shell.
-
-   If one or more ARGs are given, they are passed as additional
-   arguments to the subshell.
-
-   Does not handle /bin/sh or other shells specially
-   (setting argv[0] to "-su", passing -c only to certain shells, etc.).
-   I don't see the point in doing that, and it's ugly.
-
-   This program intentionally does not support a "wheel group" that
-   restricts who can su to UID 0 accounts.  RMS considers that to
-   be fascist.
-
-   Compile-time options:
-   -DSYSLOG_SUCCESS	Log successful su's (by default, to root) with syslog.
-   -DSYSLOG_FAILURE	Log failed su's (by default, to root) with syslog.
-
-   -DSYSLOG_NON_ROOT	Log all su's, not just those to root (UID 0).
-   Never logs attempted su's to nonexistent accounts.
-
-   Written by David MacKenzie <djm@gnu.ai.mit.edu>.  */
-
-#include <config.h>
-#include <stdio.h>
-#include <getopt.h>
-#include <sys/types.h>
-#include <pwd.h>
-#include <grp.h>
-
-#include "system.h"
-#include "getpass.h"
-
-#if HAVE_SYSLOG_H && HAVE_SYSLOG
-# include <syslog.h>
-#else
-# undef SYSLOG_SUCCESS
-# undef SYSLOG_FAILURE
-# undef SYSLOG_NON_ROOT
-#endif
-
-#if HAVE_SYS_PARAM_H
-# include <sys/param.h>
-#endif
-
-#ifndef HAVE_ENDGRENT
-# define endgrent() ((void) 0)
-#endif
-
-#ifndef HAVE_ENDPWENT
-# define endpwent() ((void) 0)
-#endif
-
-#if HAVE_SHADOW_H
-# include <shadow.h>
-#endif
-
-#include "error.h"
-
-/* The official name of this program (e.g., no 'g' prefix).  */
-#define PROGRAM_NAME "su"
-
-#define AUTHORS proper_name ("David MacKenzie")
-
-#if HAVE_PATHS_H
-# include <paths.h>
-#endif
-
-/* The default PATH for simulated logins to non-superuser accounts.  */
-#ifdef _PATH_DEFPATH
-# define DEFAULT_LOGIN_PATH _PATH_DEFPATH
-#else
-# define DEFAULT_LOGIN_PATH ":/usr/ucb:/bin:/usr/bin"
-#endif
-
-/* The default PATH for simulated logins to superuser accounts.  */
-#ifdef _PATH_DEFPATH_ROOT
-# define DEFAULT_ROOT_LOGIN_PATH _PATH_DEFPATH_ROOT
-#else
-# define DEFAULT_ROOT_LOGIN_PATH "/usr/ucb:/bin:/usr/bin:/etc"
-#endif
-
-/* The shell to run if none is given in the user's passwd entry.  */
-#define DEFAULT_SHELL "/bin/sh"
-
-/* The user to become if none is specified.  */
-#define DEFAULT_USER "root"
-
-char *crypt (char const *key, char const *salt);
-
-static void run_shell (char const *, char const *, char **, size_t)
-     ATTRIBUTE_NORETURN;
-
-/* If true, pass the '-f' option to the subshell.  */
-static bool fast_startup;
-
-/* If true, simulate a login instead of just starting a shell.  */
-static bool simulate_login;
-
-/* If true, change some environment vars to indicate the user su'd to.  */
-static bool change_environment;
-
-static struct option const longopts[] =
-{
-  {"command", required_argument, NULL, 'c'},
-  {"fast", no_argument, NULL, 'f'},
-  {"login", no_argument, NULL, 'l'},
-  {"preserve-environment", no_argument, NULL, 'p'},
-  {"shell", required_argument, NULL, 's'},
-  {GETOPT_HELP_OPTION_DECL},
-  {GETOPT_VERSION_OPTION_DECL},
-  {NULL, 0, NULL, 0}
-};
-
-/* Add NAME=VAL to the environment, checking for out of memory errors.  */
-
-static void
-xsetenv (char const *name, char const *val)
-{
-  size_t namelen = strlen (name);
-  size_t vallen = strlen (val);
-  char *string = xmalloc (namelen + 1 + vallen + 1);
-  strcpy (string, name);
-  string[namelen] = '=';
-  strcpy (string + namelen + 1, val);
-  if (putenv (string) != 0)
-    xalloc_die ();
-}
-
-#if defined SYSLOG_SUCCESS || defined SYSLOG_FAILURE
-/* Log the fact that someone has run su to the user given by PW;
-   if SUCCESSFUL is true, they gave the correct password, etc.  */
-
-static void
-log_su (struct passwd const *pw, bool successful)
-{
-  const char *new_user, *old_user, *tty;
-
-# ifndef SYSLOG_NON_ROOT
-  if (pw->pw_uid)
-    return;
-# endif
-  new_user = pw->pw_name;
-  /* The utmp entry (via getlogin) is probably the best way to identify
-     the user, especially if someone su's from a su-shell.  */
-  old_user = getlogin ();
-  if (!old_user)
-    {
-      /* getlogin can fail -- usually due to lack of utmp entry.
-         Resort to getpwuid.  */
-      errno = 0;
-      uid_t ruid = getuid ();
-      uid_t NO_UID = -1;
-      struct passwd *pwd = (ruid == NO_UID && errno ? NULL : getpwuid (ruid));
-      old_user = (pwd ? pwd->pw_name : "");
-    }
-  tty = ttyname (STDERR_FILENO);
-  if (!tty)
-    tty = "none";
-  /* 4.2BSD openlog doesn't have the third parameter.  */
-  openlog (last_component (program_name), 0
-# ifdef LOG_AUTH
-           , LOG_AUTH
-# endif
-           );
-  syslog (LOG_NOTICE,
-# ifdef SYSLOG_NON_ROOT
-          "%s(to %s) %s on %s",
-# else
-          "%s%s on %s",
-# endif
-          successful ? "" : "FAILED SU ",
-# ifdef SYSLOG_NON_ROOT
-          new_user,
-# endif
-          old_user, tty);
-  closelog ();
-}
-#endif
-
-/* Ask the user for a password.
-   Return true if the user gives the correct password for entry PW,
-   false if not.  Return true without asking for a password if run by UID 0
-   or if PW has an empty password.  */
-
-static bool
-correct_password (const struct passwd *pw)
-{
-  char *unencrypted, *encrypted, *correct;
-#if HAVE_GETSPNAM && HAVE_STRUCT_SPWD_SP_PWDP
-  /* Shadow passwd stuff for SVR3 and maybe other systems.  */
-  struct spwd *sp = getspnam (pw->pw_name);
-
-  endspent ();
-  if (sp)
-    correct = sp->sp_pwdp;
-  else
-#endif
-    correct = pw->pw_passwd;
-
-  if (getuid () == 0 || !correct || correct[0] == '\0')
-    return true;
-
-  unencrypted = getpass (_("Password:"));
-  if (!unencrypted)
-    {
-      error (0, 0, _("getpass: cannot open /dev/tty"));
-      return false;
-    }
-  encrypted = crypt (unencrypted, correct);
-  memset (unencrypted, 0, strlen (unencrypted));
-  return STREQ (encrypted, correct);
-}
-
-/* Update 'environ' for the new shell based on PW, with SHELL being
-   the value for the SHELL environment variable.  */
-
-static void
-modify_environment (const struct passwd *pw, const char *shell)
-{
-  if (simulate_login)
-    {
-      /* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.
-         Unset all other environment variables.  */
-      char const *term = getenv ("TERM");
-      if (term)
-        term = xstrdup (term);
-      environ = xmalloc ((6 + !!term) * sizeof (char *));
-      environ[0] = NULL;
-      if (term)
-        xsetenv ("TERM", term);
-      xsetenv ("HOME", pw->pw_dir);
-      xsetenv ("SHELL", shell);
-      xsetenv ("USER", pw->pw_name);
-      xsetenv ("LOGNAME", pw->pw_name);
-      xsetenv ("PATH", (pw->pw_uid
-                        ? DEFAULT_LOGIN_PATH
-                        : DEFAULT_ROOT_LOGIN_PATH));
-    }
-  else
-    {
-      /* Set HOME, SHELL, and if not becoming a super-user,
-         USER and LOGNAME.  */
-      if (change_environment)
-        {
-          xsetenv ("HOME", pw->pw_dir);
-          xsetenv ("SHELL", shell);
-          if (pw->pw_uid)
-            {
-              xsetenv ("USER", pw->pw_name);
-              xsetenv ("LOGNAME", pw->pw_name);
-            }
-        }
-    }
-}
-
-/* Become the user and group(s) specified by PW.  */
-
-static void
-change_identity (const struct passwd *pw)
-{
-#ifdef HAVE_INITGROUPS
-  errno = 0;
-  if (initgroups (pw->pw_name, pw->pw_gid) == -1)
-    error (EXIT_CANCELED, errno, _("cannot set groups"));
-  endgrent ();
-#endif
-  if (setgid (pw->pw_gid))
-    error (EXIT_CANCELED, errno, _("cannot set group id"));
-  if (setuid (pw->pw_uid))
-    error (EXIT_CANCELED, errno, _("cannot set user id"));
-}
-
-/* Run SHELL, or DEFAULT_SHELL if SHELL is empty.
-   If COMMAND is nonzero, pass it to the shell with the -c option.
-   Pass ADDITIONAL_ARGS to the shell as more arguments; there
-   are N_ADDITIONAL_ARGS extra arguments.  */
-
-static void
-run_shell (char const *shell, char const *command, char **additional_args,
-           size_t n_additional_args)
-{
-  size_t n_args = 1 + fast_startup + 2 * !!command + n_additional_args + 1;
-  char const **args = xnmalloc (n_args, sizeof *args);
-  size_t argno = 1;
-
-  if (simulate_login)
-    {
-      char *arg0;
-      char *shell_basename;
-
-      shell_basename = last_component (shell);
-      arg0 = xmalloc (strlen (shell_basename) + 2);
-      arg0[0] = '-';
-      strcpy (arg0 + 1, shell_basename);
-      args[0] = arg0;
-    }
-  else
-    args[0] = last_component (shell);
-  if (fast_startup)
-    args[argno++] = "-f";
-  if (command)
-    {
-      args[argno++] = "-c";
-      args[argno++] = command;
-    }
-  memcpy (args + argno, additional_args, n_additional_args * sizeof *args);
-  args[argno + n_additional_args] = NULL;
-  execv (shell, (char **) args);
-
-  {
-    int exit_status = (errno == ENOENT ? EXIT_ENOENT : EXIT_CANNOT_INVOKE);
-    error (0, errno, "%s", shell);
-    exit (exit_status);
-  }
-}
-
-/* Return true if SHELL is a restricted shell (one not returned by
-   getusershell), else false, meaning it is a standard shell.  */
-
-static bool
-restricted_shell (const char *shell)
-{
-  char *line;
-
-  setusershell ();
-  while ((line = getusershell ()) != NULL)
-    {
-      if (*line != '#' && STREQ (line, shell))
-        {
-          endusershell ();
-          return false;
-        }
-    }
-  endusershell ();
-  return true;
-}
-
-void
-usage (int status)
-{
-  if (status != EXIT_SUCCESS)
-    emit_try_help ();
-  else
-    {
-      printf (_("Usage: %s [OPTION]... [-] [USER [ARG]...]\n"), program_name);
-      fputs (_("\
-Change the effective user id and group id to that of USER.\n\
-\n\
-  -, -l, --login               make the shell a login shell\n\
-  -c, --command=COMMAND        pass a single COMMAND to the shell with -c\n\
-  -f, --fast                   pass -f to the shell (for csh or tcsh)\n\
-  -m, --preserve-environment   do not reset environment variables\n\
-  -p                           same as -m\n\
-  -s, --shell=SHELL            run SHELL if /etc/shells allows it\n\
-"), stdout);
-      fputs (HELP_OPTION_DESCRIPTION, stdout);
-      fputs (VERSION_OPTION_DESCRIPTION, stdout);
-      fputs (_("\
-\n\
-A mere - implies -l.   If USER not given, assume root.\n\
-"), stdout);
-      emit_ancillary_info ();
-    }
-  exit (status);
-}
-
-int
-main (int argc, char **argv)
-{
-  int optc;
-  const char *new_user = DEFAULT_USER;
-  char *command = NULL;
-  char *shell = NULL;
-  struct passwd *pw;
-  struct passwd pw_copy;
-
-  initialize_main (&argc, &argv);
-  set_program_name (argv[0]);
-  setlocale (LC_ALL, "");
-  bindtextdomain (PACKAGE, LOCALEDIR);
-  textdomain (PACKAGE);
-
-  initialize_exit_failure (EXIT_CANCELED);
-  atexit (close_stdout);
-
-  fast_startup = false;
-  simulate_login = false;
-  change_environment = true;
-
-  while ((optc = getopt_long (argc, argv, "c:flmps:", longopts, NULL)) != -1)
-    {
-      switch (optc)
-        {
-        case 'c':
-          command = optarg;
-          break;
-
-        case 'f':
-          fast_startup = true;
-          break;
-
-        case 'l':
-          simulate_login = true;
-          break;
-
-        case 'm':
-        case 'p':
-          change_environment = false;
-          break;
-
-        case 's':
-          shell = optarg;
-          break;
-
-        case_GETOPT_HELP_CHAR;
-
-        case_GETOPT_VERSION_CHAR (PROGRAM_NAME, AUTHORS);
-
-        default:
-          usage (EXIT_CANCELED);
-        }
-    }
-
-  if (optind < argc && STREQ (argv[optind], "-"))
-    {
-      simulate_login = true;
-      ++optind;
-    }
-  if (optind < argc)
-    new_user = argv[optind++];
-
-  pw = getpwnam (new_user);
-  if (! (pw && pw->pw_name && pw->pw_name[0] && pw->pw_dir && pw->pw_dir[0]
-         && pw->pw_passwd))
-    error (EXIT_CANCELED, 0, _("user %s does not exist"), new_user);
-
-  /* Make a copy of the password information and point pw at the local
-     copy instead.  Otherwise, some systems (e.g. GNU/Linux) would clobber
-     the static data through the getlogin call from log_su.
-     Also, make sure pw->pw_shell is a nonempty string.
-     It may be NULL when NEW_USER is a username that is retrieved via NIS (YP),
-     but that doesn't have a default shell listed.  */
-  pw_copy = *pw;
-  pw = &pw_copy;
-  pw->pw_name = xstrdup (pw->pw_name);
-  pw->pw_passwd = xstrdup (pw->pw_passwd);
-  pw->pw_dir = xstrdup (pw->pw_dir);
-  pw->pw_shell = xstrdup (pw->pw_shell && pw->pw_shell[0]
-                          ? pw->pw_shell
-                          : DEFAULT_SHELL);
-  endpwent ();
-
-  if (!correct_password (pw))
-    {
-#ifdef SYSLOG_FAILURE
-      log_su (pw, false);
-#endif
-      error (EXIT_CANCELED, 0, _("incorrect password"));
-    }
-#ifdef SYSLOG_SUCCESS
-  else
-    {
-      log_su (pw, true);
-    }
-#endif
-
-  if (!shell && !change_environment)
-    shell = getenv ("SHELL");
-  if (shell && getuid () != 0 && restricted_shell (pw->pw_shell))
-    {
-      /* The user being su'd to has a nonstandard shell, and so is
-         probably a uucp account or has restricted access.  Don't
-         compromise the account by allowing access with a standard
-         shell.  */
-      error (0, 0, _("using restricted shell %s"), pw->pw_shell);
-      shell = NULL;
-    }
-  shell = xstrdup (shell ? shell : pw->pw_shell);
-  modify_environment (pw, shell);
-
-  change_identity (pw);
-  if (simulate_login && chdir (pw->pw_dir) != 0)
-    error (0, errno, _("warning: cannot change directory to %s"), pw->pw_dir);
-
-  /* error() flushes stderr, but does not check for write failure.
-     Normally, we would catch this via our atexit() hook of
-     close_stdout, but execv() gets in the way.  If stderr
-     encountered a write failure, there is no need to try calling
-     error() again.  */
-  if (ferror (stderr))
-    exit (EXIT_CANCELED);
-
-  run_shell (shell, command, argv + optind, MAX (0, argc - optind));
-}