145 lines
4.2 KiB
C
145 lines
4.2 KiB
C
/*-
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* Copyright (c) 2002 Networks Associates Technology, Inc.
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* All rights reserved.
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*
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* This software was developed for the FreeBSD Project by ThinkSec AS and
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* NAI Labs, the Security Research Division of Network Associates, Inc.
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* under DARPA/SPAWAR contract N66001-01-C-8035 ("CBOSS"), as part of the
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* DARPA CHATS research program.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote
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* products derived from this software without specific prior written
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* permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*
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* $P4: //depot/projects/openpam/bin/su/su.c#5 $
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*/
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#include <sys/param.h>
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#include <sys/wait.h>
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#include <err.h>
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#include <pwd.h>
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#include <stdio.h>
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#include <syslog.h>
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#include <unistd.h>
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#include <security/pam_appl.h>
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#include <security/openpam.h>
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static pam_handle_t *pamh;
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static struct pam_conv pamc;
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static void
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usage(void)
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{
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fprintf(stderr, "Usage: su [login [args]]\n");
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exit(1);
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}
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static int
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check(const char *func, int pam_err)
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{
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if (pam_err == PAM_SUCCESS || pam_err == PAM_NEW_AUTHTOK_REQD)
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return pam_err;
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openlog("su", LOG_CONS, LOG_AUTH);
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syslog(LOG_ERR, "%s(): %s", func, pam_strerror(pamh, pam_err));
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errx(1, "Sorry.");
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}
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int
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main(int argc, char *argv[])
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{
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char hostname[MAXHOSTNAMELEN];
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const char *user, *tty;
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struct passwd *pwd;
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int o, status;
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pid_t pid;
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while ((o = getopt(argc, argv, "h")) != -1)
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switch (o) {
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case 'h':
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default:
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usage();
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}
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argc -= optind;
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argv += optind;
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/* initialize PAM */
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pamc.conv = &openpam_ttyconv;
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pam_start("su", argc ? *argv : "root", &pamc, &pamh);
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/* set some items */
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gethostname(hostname, sizeof(hostname));
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check("pam_set_item", pam_set_item(pamh, PAM_RHOST, hostname));
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user = getlogin();
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check("pam_set_item", pam_set_item(pamh, PAM_RUSER, user));
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tty = ttyname(STDERR_FILENO);
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check("pam_set_item", pam_set_item(pamh, PAM_TTY, tty));
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/* authenticate the applicant */
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check("pam_authenticate", pam_authenticate(pamh, 0));
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if (check("pam_acct_mgmt", pam_acct_mgmt(pamh, 0)) ==
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PAM_NEW_AUTHTOK_REQD)
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check("pam_chauthtok",
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pam_chauthtok(pamh, PAM_CHANGE_EXPIRED_AUTHTOK));
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/* establish the requested credentials */
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check("pam_setcred", pam_setcred(pamh, PAM_ESTABLISH_CRED));
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/* authentication succeeded; open a session */
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check("pam_open_session", pam_open_session(pamh, 0));
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if (initgroups(pwd->pw_name, pwd->pw_gid) == -1)
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err(1, "initgroups()");
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if (setuid(pwd->pw_uid) == -1)
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err(1, "setuid()");
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/* XXX export environment variables */
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switch ((pid = fork())) {
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case -1:
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err(1, "fork()");
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case 0:
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/* child: start a shell */
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*argv = pwd->pw_shell;
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execvp(*argv, argv);
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err(1, "execvp()");
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default:
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/* parent: wait for child to exit */
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waitpid(pid, &status, 0);
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if (WIFEXITED(status))
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status = WEXITSTATUS(status);
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else
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status = 1;
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}
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/* close the session and release PAM resources */
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check("pam_close_session", pam_close_session(pamh, 0));
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check("pam_end", pam_end(pamh, 0));
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exit(status);
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}
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