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/* Hurdish su
Copyright (C) 1996 Free Software Foundation, Inc.
Written by Miles Bader <miles@gnu.ai.mit.edu>
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 2, 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, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
#include <hurd.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <paths.h>
#include <ctype.h>
#include <utmp.h>
#include <pwd.h>
#include <grp.h>
#include <netdb.h>
#include <time.h>
#ifdef HAVE_LIBCRYPT
#include <crypt.h>
#else
#warning "No crypt on this system! Using plain-text passwords."
#define crypt(password, encrypted) password
#endif
#include <netinet/in.h>
#include <arpa/inet.h>
#include <sys/fcntl.h>
#include <argp.h>
#include <argz.h>
#include <envz.h>
#include <idvec.h>
#include <error.h>
#include <timefmt.h>
#include <hurd/lookup.h>
static struct argp_option options[] =
{
{"add", 'a', "USER", 0, "Add following ids"},
{"remove", 'r', "USER", 0, "Remove following ids"},
{"user", 'u', "USER", 0, "Add USER to the effective uids"},
{"avail-user",'U', "USER", 0, "Add USER to the available uids"},
{"group", 'g', "GROUP", 0, "Add GROUP to the effective groups"},
{"avail-group",'G',"GROUP", 0, "Add GROUP to the available groups"},
{0, 0}
};
static char *args_doc = "[USER...]";
static char *doc = "Modify authentication of existing processes"
"\vA USER specified as an argument adds (or removes) that user's groups as"
" well. When removing groups implied by such an argument, the groups to"
" which uids remaining in the process after any we remove are ignored."
"\nUids and groups specified with options are used as-is.";
/* Full set of desired authorization. XXX msg_del_auth doesn't allow such
fine control. */
struct auth
{
struct idvec euids, egids; /* Effective ids. */
struct idvec auids, agids; /* Available ids. */
};
/* Ids of our parent process, with the effect of this program being su'd
removed. */
static struct idvec parent_uids = {0}, parent_gids = {0};
/* Make sure that the parent_[ug]ids are filled in. To make them useful for
su'ing, each is the avail ids with all effective ids but the first
appended; this gets rid of the effect of login being suid, and is useful
as the new process's avail id list (e.g., the real id is right). */
static void
need_parent_ids ()
{
if (parent_uids.num == 0 && parent_gids.num == 0)
{
struct idvec *p_eff_uids = make_idvec ();
struct idvec *p_eff_gids = make_idvec ();
if (!p_eff_uids || !p_eff_gids)
err = ENOMEM;
if (! err)
err = idvec_merge_auth (p_eff_uids, parent_uids,
p_eff_gids, parent_gids,
parent_auth);
if (! err)
{
idvec_delete (p_eff_uids, 0); /* Counteract setuid. */
idvec_delete (p_eff_gids, 0);
err = idvec_merge (parent_uids, p_eff_uids);
if (! err)
err = idvec_merge (parent_gids, p_eff_gids);
}
if (err)
error (39, err, "Can't get uids");
}
}
/* Returns true if the *caller* of this login program has UID. */
static int
parent_has_uid (uid_t uid)
{
need_parent_ids ();
return idvec_contains (parent_uids, uid);
}
/* Returns true if the *caller* of this login program has GID. */
static int
parent_has_gid (gid_t gid)
{
need_parent_ids ();
return idvec_contains (parent_gids, gid);
}
/* Returns the number of parent uids. */
static int
count_parent_uids ()
{
need_parent_ids ();
return parent_uids.num;
}
/* Returns the number of parent gids. */
static int
count_parent_gids ()
{
need_parent_ids ();
return parent_gids.num;
}
/* Make sure the user should be allowed to do this. */
void verify_passwd (const char *name, const char *password,
uid_t id, int is_group, structh auth *auth)
{
char *prompt, *unencrypted, *encrypted;
if (!password || !*password
|| idvec_contains (is_group ? auth->egids : auth->euids, id)
|| idvec_contains (is_group ? auth->agids : auth->auids, id)
|| (no_passwd
&& (parent_has_uid (0)
|| (is_group ? parent_has_uid (id) : parent_has_gid (id)))))
return; /* Already got this one. */
if (name)
asprintf (&prompt, "Password for %s%s:",
is_group ? "group " : "", name);
else
prompt = "Password:";
unencrypted = getpass (prompt);
encrypted = crypt (unencrypted, password);
/* Paranoia may destroya. */
memset (unencrypted, 0, strlen (unencrypted));
if (name)
free (prompt);
if (strcmp (encrypted, password) != 0)
error (50, 0, "Incorrect password", 0);
}
void
main(int argc, char *argv[])
{
error_t err = 0;
struct auth add, remove;
/* Parse our options... */
error_t parse_opt (int key, char *arg, struct argp_state *state)
{
switch (key)
{
case ARGP_KEY_NO_ARGS:
arg = "0"; /* root */
/* fall through. */
case 'u':
case 'U':
{
struct passwd *pw =
isdigit (*user) ? getpwuid (atoi (user)) : getpwnam (user);
/* True if this is the user arg and there were no user options. */
if (! pw)
error (10, 0, "%s: Unknown user", user);
verify_passwd (state->argv[state->next] ? pw->pw_name : 0,
pw->pw_passwd, pw->pw_uid, 0, &auth);
if (key == 'u')
idvec_add_new (&auth.euids, pw->pw_uid);
else if (key == 'U')
/* Add available ids instead of effective ones. */
idvec_add_new (&auth.auids, pw->pw_uid);
else
/* A plain argument. Add both the specified user and any
associated groups. */
{
/* Effective */
idvec_add_new (&auth.euids, 0, pw->pw_uid);
idvec_add_new (&auth.egids, 0, pw->pw_gid);
}
}
break;
case 'g':
case 'G':
{
struct group *gr =
isdigit (*arg) ? getgrgid (atoi (arg)) : getgrnam (arg);
if (! gr)
error (11, 0, "%s: Unknown group", arg);
verify_passwd (gr->gr_name, gr->gr_passwd, gr->gr_gid, 1, &auth);
idvec_add_new (key == 'g' ? &auth.egids : &auth.agids, gr->gr_gid);
}
break;
default:
return ARGP_ERR_UNKNOWN;
}
return 0;
}
struct argp argp = {options, parse_opt, args_doc, doc};
memset (add, 0, sizeof add);
memset (remove, 0, sizeof remove);
err =
auth_makeauth (getauth (), 0, MACH_MSG_TYPE_COPY_SEND, 0,
&auth.euids->ids, &auth.euids->num,
&auth.auids->ids, &auth.auids->num,
&auth.egids->ids, &auth.egids->num,
&auth.agids->ids, &auth.agids->num,
&auth);
if (err)
error (3, err, "Authentication failure", 0);
exit(0);
}
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