333 lines
8.7 KiB
C
333 lines
8.7 KiB
C
/*
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* Copyright (c) 1994-1996,1998-2004 Todd C. Miller <Todd.Miller@courtesan.com>
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*
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* Permission to use, copy, modify, and distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
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* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
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* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
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* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
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*
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* Sponsored in part by the Defense Advanced Research Projects
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* Agency (DARPA) and Air Force Research Laboratory, Air Force
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* Materiel Command, USAF, under agreement number F39502-99-1-0512.
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*/
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#include <config.h>
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#include <sys/types.h>
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#include <sys/param.h>
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#include <sys/stat.h>
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#include <stdio.h>
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#ifdef STDC_HEADERS
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# include <stdlib.h>
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# include <stddef.h>
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#else
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# ifdef HAVE_STDLIB_H
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# include <stdlib.h>
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# endif
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#endif /* STDC_HEADERS */
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#ifdef HAVE_STRING_H
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# include <string.h>
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#else
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# ifdef HAVE_STRINGS_H
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# include <strings.h>
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# endif
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#endif /* HAVE_STRING_H */
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#ifdef HAVE_UNISTD_H
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# include <unistd.h>
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#endif /* HAVE_UNISTD_H */
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#include <pwd.h>
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#include <errno.h>
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#include <grp.h>
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#ifdef HAVE_LOGIN_CAP_H
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# include <login_cap.h>
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#endif
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#include "sudo.h"
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#ifndef lint
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static const char rcsid[] = "$Sudo$";
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#endif /* lint */
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#ifdef __TANDEM
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# define ROOT_UID 65535
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#else
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# define ROOT_UID 0
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#endif
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/*
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* Prototypes
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*/
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static void runas_setup __P((void));
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static void fatal __P((char *, int));
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#ifdef HAVE_SETRESUID
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/*
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* Set real and effective and saved uids and gids based on perm.
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* We always retain a saved uid of 0 unless we are headed for an exec().
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* We only flip the effective gid since it only changes for PERM_SUDOERS.
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* This version of set_perms() works fine with the "stay_setuid" option.
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*/
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void
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set_perms(perm)
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int perm;
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{
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int error;
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switch (perm) {
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case PERM_FULL_ROOT:
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case PERM_ROOT:
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if (setresuid(ROOT_UID, ROOT_UID, ROOT_UID))
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fatal("setresuid(ROOT_UID, ROOT_UID, ROOT_UID) failed, your operating system may have a broken setresuid() function\nTry running configure with --disable-setresuid", 0);
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break;
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case PERM_USER:
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(void) setresgid(-1, user_gid, -1);
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if (setresuid(user_uid, user_uid, ROOT_UID))
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fatal("setresuid(user_uid, user_uid, ROOT_UID)", 1);
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break;
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case PERM_FULL_USER:
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/* headed for exec() */
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(void) setgid(user_gid);
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if (setresuid(user_uid, user_uid, user_uid))
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fatal("setresuid(user_uid, user_uid, user_uid)", 1);
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break;
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case PERM_RUNAS:
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if (setresuid(-1, runas_pw->pw_uid, -1))
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fatal("unable to change to runas uid", 1);
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break;
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case PERM_FULL_RUNAS:
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/* headed for exec(), assume euid == ROOT_UID */
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runas_setup();
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error = setresuid(def_stay_setuid ?
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user_uid : runas_pw->pw_uid,
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runas_pw->pw_uid, runas_pw->pw_uid);
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if (error)
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fatal("unable to change to runas uid", 1);
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break;
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case PERM_SUDOERS:
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/* assume euid == ROOT_UID, ruid == user */
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if (setresgid(-1, SUDOERS_GID, -1))
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fatal("unable to change to sudoers gid", 1);
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/*
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* If SUDOERS_UID == ROOT_UID and SUDOERS_MODE
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* is group readable we use a non-zero
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* uid in order to avoid NFS lossage.
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* Using uid 1 is a bit bogus but should
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* work on all OS's.
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*/
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if (SUDOERS_UID == ROOT_UID) {
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if ((SUDOERS_MODE & 040) && setresuid(ROOT_UID, 1, ROOT_UID))
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fatal("setresuid(ROOT_UID, 1, ROOT_UID)", 1);
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} else {
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if (setresuid(ROOT_UID, SUDOERS_UID, ROOT_UID))
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fatal("setresuid(ROOT_UID, SUDOERS_UID, ROOT_UID)", 1);
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}
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break;
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case PERM_TIMESTAMP:
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if (setresuid(ROOT_UID, timestamp_uid, ROOT_UID))
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fatal("setresuid(ROOT_UID, timestamp_uid, ROOT_UID)", 1);
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break;
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}
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}
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#else
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# ifdef HAVE_SETREUID
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/*
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* Set real and effective uids and gids based on perm.
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* We always retain a real or effective uid of ROOT_UID unless
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* we are headed for an exec().
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* This version of set_perms() works fine with the "stay_setuid" option.
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*/
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void
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set_perms(perm)
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int perm;
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{
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int error;
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switch (perm) {
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case PERM_FULL_ROOT:
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case PERM_ROOT:
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if (setreuid(-1, ROOT_UID))
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fatal("setreuid(-1, ROOT_UID) failed, your operating system may have a broken setreuid() function\nTry running configure with --disable-setreuid", 0);
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if (setuid(ROOT_UID))
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fatal("setuid(ROOT_UID)", 1);
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break;
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case PERM_USER:
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(void) setregid(-1, user_gid);
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if (setreuid(ROOT_UID, user_uid))
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fatal("setreuid(ROOT_UID, user_uid)", 1);
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break;
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case PERM_FULL_USER:
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/* headed for exec() */
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(void) setgid(user_gid);
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if (setreuid(user_uid, user_uid))
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fatal("setreuid(user_uid, user_uid)", 1);
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break;
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case PERM_RUNAS:
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if (setreuid(-1, runas_pw->pw_uid))
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fatal("unable to change to runas uid", 1);
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break;
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case PERM_FULL_RUNAS:
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/* headed for exec(), assume euid == ROOT_UID */
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runas_setup();
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error = setreuid(def_stay_setuid ?
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user_uid : runas_pw->pw_uid,
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runas_pw->pw_uid);
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if (error)
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fatal("unable to change to runas uid", 1);
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break;
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case PERM_SUDOERS:
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/* assume euid == ROOT_UID, ruid == user */
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if (setregid(-1, SUDOERS_GID))
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fatal("unable to change to sudoers gid", 1);
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/*
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* If SUDOERS_UID == ROOT_UID and SUDOERS_MODE
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* is group readable we use a non-zero
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* uid in order to avoid NFS lossage.
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* Using uid 1 is a bit bogus but should
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* work on all OS's.
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*/
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if (SUDOERS_UID == ROOT_UID) {
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if ((SUDOERS_MODE & 040) && setreuid(ROOT_UID, 1))
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fatal("setreuid(ROOT_UID, 1)", 1);
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} else {
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if (setreuid(ROOT_UID, SUDOERS_UID))
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fatal("setreuid(ROOT_UID, SUDOERS_UID)", 1);
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}
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break;
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case PERM_TIMESTAMP:
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if (setreuid(ROOT_UID, timestamp_uid))
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fatal("setreuid(ROOT_UID, timestamp_uid)", 1);
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break;
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}
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}
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# else /* !HAVE_SETRESUID && !HAVE_SETREUID */
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/*
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* Set uids and gids based on perm via setuid() and setgid().
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* NOTE: does not support the "stay_setuid" or timestampowner options.
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* Also, SUDOERS_UID and SUDOERS_GID are not used.
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*/
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void
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set_perms(perm)
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int perm;
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{
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switch (perm) {
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case PERM_FULL_ROOT:
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case PERM_ROOT:
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if (setuid(ROOT_UID))
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fatal("setuid(ROOT_UID)", 1);
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break;
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case PERM_FULL_USER:
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(void) setgid(user_gid);
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if (setuid(user_uid))
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fatal("setuid(user_uid)", 1);
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break;
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case PERM_FULL_RUNAS:
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runas_setup();
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if (setuid(runas_pw->pw_uid))
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fatal("unable to change to runas uid", 1);
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break;
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case PERM_USER:
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case PERM_SUDOERS:
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case PERM_RUNAS:
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case PERM_TIMESTAMP:
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/* Unsupported since we can't set euid. */
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break;
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}
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}
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# endif /* HAVE_SETREUID */
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#endif /* HAVE_SETRESUID */
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static void
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runas_setup()
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{
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#ifdef HAVE_LOGIN_CAP_H
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int error, flags;
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extern login_cap_t *lc;
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#endif
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if (runas_pw->pw_name != NULL) {
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#ifdef HAVE_PAM
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pam_prep_user(runas_pw);
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#endif /* HAVE_PAM */
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#ifdef HAVE_LOGIN_CAP_H
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if (def_use_loginclass) {
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/*
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* We don't have setusercontext() set the user since we
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* may only want to set the effective uid. Depending on
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* sudoers and/or command line arguments we may not want
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* setusercontext() to call initgroups().
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*/
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flags = LOGIN_SETRESOURCES|LOGIN_SETPRIORITY;
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if (!def_preserve_groups)
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SET(flags, LOGIN_SETGROUP);
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else if (setgid(runas_pw->pw_gid))
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perror("cannot set gid to runas gid");
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error = setusercontext(lc, runas_pw,
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runas_pw->pw_uid, flags);
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if (error) {
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if (runas_pw->pw_uid != ROOT_UID)
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fatal("unable to set user context", 1);
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else
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perror("unable to set user context");
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}
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} else
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#endif /* HAVE_LOGIN_CAP_H */
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{
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if (setgid(runas_pw->pw_gid))
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perror("cannot set gid to runas gid");
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#ifdef HAVE_INITGROUPS
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/*
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* Initialize group vector unless asked not to.
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*/
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if (!def_preserve_groups &&
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initgroups(*user_runas, runas_pw->pw_gid) < 0)
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perror("cannot set group vector");
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#endif /* HAVE_INITGROUPS */
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}
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}
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}
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static void
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fatal(str, printerr)
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char *str;
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int printerr;
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{
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if (str) {
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if (printerr)
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perror(str);
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else {
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fputs(str, stderr);
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fputc('\n', stderr);
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}
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}
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exit(1);
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}
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