openssh/uidswap.c
Damien Miller caf6dd6d21 - More OpenBSD updates:
- deraadt@cvs.openbsd.org 2000/08/24 15:46:59
     [scp.c]
     off_t in sink, to fix files > 2GB, i think, test is still running ;-)
   - deraadt@cvs.openbsd.org 2000/08/25 10:10:06
     [session.c]
     Wall
   - markus@cvs.openbsd.org  2000/08/26 04:33:43
     [compat.c]
     ssh.com-2.3.0
   - markus@cvs.openbsd.org  2000/08/27 12:18:05
     [compat.c]
     compatibility with future ssh.com versions
   - deraadt@cvs.openbsd.org 2000/08/27 21:50:55
     [auth-krb4.c session.c ssh-add.c sshconnect.c uidswap.c]
     print uid/gid as unsigned
   - markus@cvs.openbsd.org  2000/08/28 13:51:00
     [ssh.c]
     enable -n and -f for ssh2
   - markus@cvs.openbsd.org  2000/08/28 14:19:53
     [ssh.c]
     allow combination of -N and -f
   - markus@cvs.openbsd.org  2000/08/28 14:20:56
     [util.c]
     util.c
   - markus@cvs.openbsd.org  2000/08/28 14:22:02
     [util.c]
     undo
   - markus@cvs.openbsd.org  2000/08/28 14:23:38
     [util.c]
     don't complain if setting NONBLOCK fails with ENODEV
2000-08-29 11:33:50 +11:00

100 lines
2.6 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Created: Sat Sep 9 01:56:14 1995 ylo
* Code for uid-swapping.
*/
#include "includes.h"
RCSID("$OpenBSD: uidswap.c,v 1.8 2000/08/28 03:50:54 deraadt Exp $");
#include "ssh.h"
#include "uidswap.h"
#ifdef WITH_IRIX_AUDIT
#include <sat.h>
#endif /* WITH_IRIX_AUDIT */
/*
* Note: all these functions must work in all of the following cases:
* 1. euid=0, ruid=0
* 2. euid=0, ruid!=0
* 3. euid!=0, ruid!=0
* Additionally, they must work regardless of whether the system has
* POSIX saved uids or not.
*/
#ifdef _POSIX_SAVED_IDS
/* Lets assume that posix saved ids also work with seteuid, even though that
is not part of the posix specification. */
#define SAVED_IDS_WORK_WITH_SETEUID
/* Saved effective uid. */
static uid_t saved_euid = 0;
#endif /* _POSIX_SAVED_IDS */
/*
* Temporarily changes to the given uid. If the effective user
* id is not root, this does nothing. This call cannot be nested.
*/
void
temporarily_use_uid(uid_t uid)
{
#ifdef SAVED_IDS_WORK_WITH_SETEUID
/* Save the current euid. */
saved_euid = geteuid();
/* Set the effective uid to the given (unprivileged) uid. */
if (seteuid(uid) == -1)
debug("seteuid %u: %.100s", (u_int) uid, strerror(errno));
#else /* SAVED_IDS_WORK_WITH_SETUID */
/* Propagate the privileged uid to all of our uids. */
if (setuid(geteuid()) < 0)
debug("setuid %u: %.100s", (u_int) geteuid(), strerror(errno));
/* Set the effective uid to the given (unprivileged) uid. */
if (seteuid(uid) == -1)
debug("seteuid %u: %.100s", (u_int) uid, strerror(errno));
#endif /* SAVED_IDS_WORK_WITH_SETEUID */
}
/*
* Restores to the original uid.
*/
void
restore_uid()
{
#ifdef SAVED_IDS_WORK_WITH_SETEUID
/* Set the effective uid back to the saved uid. */
if (seteuid(saved_euid) < 0)
debug("seteuid %u: %.100s", (u_int) saved_euid, strerror(errno));
#else /* SAVED_IDS_WORK_WITH_SETEUID */
/*
* We are unable to restore the real uid to its unprivileged value.
* Propagate the real uid (usually more privileged) to effective uid
* as well.
*/
setuid(getuid());
#endif /* SAVED_IDS_WORK_WITH_SETEUID */
}
/*
* Permanently sets all uids to the given uid. This cannot be
* called while temporarily_use_uid is effective.
*/
void
permanently_set_uid(uid_t uid)
{
#ifdef WITH_IRIX_AUDIT
if (sysconf(_SC_AUDIT)) {
debug("Setting sat id to %d", (int) uid);
if (satsetid(uid))
debug("error setting satid: %.100s", strerror(errno));
}
#endif /* WITH_IRIX_AUDIT */
if (setuid(uid) < 0)
debug("setuid %u: %.100s", (u_int) uid, strerror(errno));
}