openssh/uidswap.c
Ben Lindstrom 226cfa0378 Hopefully things did not get mixed around too much. It compiles under
Linux and works.  So that is at least a good sign. =)
20010122
 - (bal) OpenBSD Resync
   - markus@cvs.openbsd.org 2001/01/19 12:45:26 GMT 2001 by markus
     [servconf.c ssh.h sshd.c]
     only auth-chall.c needs #ifdef SKEY
   - markus@cvs.openbsd.org 2001/01/19 15:55:10 GMT 2001 by markus
     [auth-krb4.c auth-options.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c
      auth1.c auth2.c channels.c clientloop.c dh.c dispatch.c nchan.c
      packet.c pathname.h readconf.c scp.c servconf.c serverloop.c
      session.c ssh-add.c ssh-keygen.c ssh-keyscan.c ssh.c ssh.h
      ssh1.h sshconnect1.c sshd.c ttymodes.c]
     move ssh1 definitions to ssh1.h, pathnames to pathnames.h
   - markus@cvs.openbsd.org 2001/01/19 16:48:14
     [sshd.8]
     fix typo; from stevesk@
   - markus@cvs.openbsd.org 2001/01/19 16:50:58
     [ssh-dss.c]
     clear and free digest, make consistent with other code (use dlen); from
     stevesk@
   - markus@cvs.openbsd.org 2001/01/20 15:55:20 GMT 2001 by markus
     [auth-options.c auth-options.h auth-rsa.c auth2.c]
     pass the filename to auth_parse_options()
   - markus@cvs.openbsd.org 2001/01/20 17:59:40 GMT 2001
     [readconf.c]
     fix SIGSEGV from -o ""; problem noted by jehsom@togetherweb.com
   - stevesk@cvs.openbsd.org 2001/01/20 18:20:29
     [sshconnect2.c]
     dh_new_group() does not return NULL.  ok markus@
   - markus@cvs.openbsd.org 2001/01/20 21:33:42
     [ssh-add.c]
     do not loop forever if askpass does not exist; from
     andrew@pimlott.ne.mediaone.net
   - djm@cvs.openbsd.org 2001/01/20 23:00:56
     [servconf.c]
     Check for NULL return from strdelim; ok markus
   - djm@cvs.openbsd.org 2001/01/20 23:02:07
     [readconf.c]
     KNF; ok markus
   - jakob@cvs.openbsd.org 2001/01/21 9:00:33
     [ssh-keygen.1]
     remove -R flag; ok markus@
   - markus@cvs.openbsd.org 2001/01/21 19:05:40
     [atomicio.c automicio.h auth-chall.c auth-krb4.c auth-options.c
      auth-options.h auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c
      auth.c auth.h auth1.c auth2-chall.c auth2.c authfd.c authfile.c
      bufaux.c  bufaux.h buffer.c canahost.c canahost.h channels.c
      cipher.c cli.c clientloop.c clientloop.h compat.c compress.c
      deattack.c dh.c dispatch.c groupaccess.c hmac.c hostfile.c kex.c
      key.c key.h log-client.c log-server.c log.c log.h login.c login.h
      match.c misc.c misc.h nchan.c packet.c pty.c radix.h readconf.c
      readpass.c readpass.h rsa.c scp.c servconf.c serverloop.c serverloop.h
      session.c sftp-server.c ssh-add.c ssh-agent.c ssh-dss.c ssh-keygen.c
      ssh-keyscan.c ssh-rsa.c ssh.c ssh.h sshconnect.c sshconnect.h
      sshconnect1.c sshconnect2.c sshd.c tildexpand.c tildexpand.h
      ttysmodes.c uidswap.c xmalloc.c]
     split ssh.h and try to cleanup the #include mess. remove unnecessary
     #includes.  rename util.[ch] -> misc.[ch]
 - (bal) renamed 'PIDDIR' to '_PATH_SSH_PIDDIR' to match OpenBSD tree
 - (bal) Moved #ifdef KRB4 in auth-krb4.c above the #include to resolve
   conflict when compiling for non-kerb install
 - (bal) removed the #ifdef SKEY in auth1.c to match Markus' changes
   on 1/19.
2001-01-22 05:34:40 +00:00

92 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 1.13 2001/01/21 19:06:01 markus Exp $");
#include "log.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));
}