openssh/uidswap.c
Ben Lindstrom 46c162204b One way to massive patch. <sigh> It compiles and works under Linux..
And I think I have all the bits right from the OpenBSD tree.
20001222
 - Updated RCSID for pty.c
 - (bal) OpenBSD CVS Updates:
  - markus@cvs.openbsd.org 2000/12/21 15:10:16
    [auth-rh-rsa.c hostfile.c hostfile.h sshconnect.c]
    print keyfile:line for changed hostkeys, for deraadt@, ok deraadt@
  - markus@cvs.openbsd.org 2000/12/20 19:26:56
    [authfile.c]
    allow ssh -i userkey for root
  - markus@cvs.openbsd.org 2000/12/20 19:37:21
    [authfd.c authfd.h kex.c sshconnect2.c sshd.c uidswap.c uidswap.h]
    fix prototypes; from stevesk@pobox.com
  - markus@cvs.openbsd.org 2000/12/20 19:32:08
    [sshd.c]
    init pointer to NULL; report from Jan.Ivan@cern.ch
  - markus@cvs.openbsd.org 2000/12/19 23:17:54
    [auth-krb4.c auth-options.c auth-options.h auth-rhosts.c auth-rsa.c
     auth1.c auth2-skey.c auth2.c authfd.c authfd.h authfile.c bufaux.c
     bufaux.h buffer.c canohost.c channels.c clientloop.c compress.c
     crc32.c deattack.c getput.h hmac.c hmac.h hostfile.c kex.c kex.h
     key.c key.h log.c login.c match.c match.h mpaux.c mpaux.h packet.c
     packet.h radix.c readconf.c rsa.c scp.c servconf.c servconf.h
     serverloop.c session.c sftp-server.c ssh-agent.c ssh-dss.c ssh-dss.h
     ssh-keygen.c ssh-keyscan.c ssh-rsa.c ssh-rsa.h ssh.c ssh.h  uuencode.c
     uuencode.h sshconnect1.c sshconnect2.c sshd.c tildexpand.c]
    replace 'unsigned bla' with 'u_bla' everywhere. also replace 'char
    unsigned' with u_char.
2000-12-22 01:43:59 +00:00

94 lines
2.7 KiB
C

/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
* All rights reserved
* Code for uid-swapping.
*
* As far as I am concerned, the code I have written for this software
* can be used freely for any purpose. Any derived versions of this
* software must be clearly marked as such, and if the derived work is
* incompatible with the protocol description in the RFC file, it must be
* called by a name other than "ssh" or "Secure Shell".
*/
#include "includes.h"
RCSID("$OpenBSD: uidswap.c,v 1.11 2000/12/20 19:37:22 markus Exp $");
#include "ssh.h"
#include "uidswap.h"
/*
* 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_SETEUID */
/* 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(void)
{
#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)
{
if (setuid(uid) < 0)
debug("setuid %u: %.100s", (u_int) uid, strerror(errno));
}