+/*
+ * Copyright (c) 1988 The Regents of the University of California.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ * must display the following acknowledgement:
+ * This product includes software developed by the University of
+ * California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ * may be used to endorse or promote products derived from this software
+ * without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#ifndef lint
+char copyright[] =
+"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
+ All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)su.c 5.26 (Berkeley) 7/6/91";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+#include <syslog.h>
+#include <stdio.h>
+#include <pwd.h>
+#include <grp.h>
+#include <string.h>
+#include <unistd.h>
+#include <paths.h>
+
+#ifdef KERBEROS
+#include <kerberosIV/des.h>
+#include <kerberosIV/krb.h>
+#include <netdb.h>
+
+#define ARGSTR "-Kflm"
+
+int use_kerberos = 1;
+#else
+#define ARGSTR "-flm"
+#endif
+
+main(argc, argv)
+ int argc;
+ char **argv;
+{
+ extern char **environ;
+ extern int errno, optind;
+ register struct passwd *pwd;
+ register char *p, **g;
+ struct group *gr;
+ uid_t ruid, getuid();
+ int asme, ch, asthem, fastlogin, prio;
+ enum { UNSET, YES, NO } iscsh = UNSET;
+ char *user, *shell, *username, *cleanenv[2], *nargv[4], **np;
+ char shellbuf[MAXPATHLEN];
+ char *crypt(), *getpass(), *getenv(), *getlogin(), *ontty();
+
+ np = &nargv[3];
+ *np-- = NULL;
+ asme = asthem = fastlogin = 0;
+ while ((ch = getopt(argc, argv, ARGSTR)) != EOF)
+ switch((char)ch) {
+#ifdef KERBEROS
+ case 'K':
+ use_kerberos = 0;
+ break;
+#endif
+ case 'f':
+ fastlogin = 1;
+ break;
+ case '-':
+ case 'l':
+ asme = 0;
+ asthem = 1;
+ break;
+ case 'm':
+ asme = 1;
+ asthem = 0;
+ break;
+ case '?':
+ default:
+ (void)fprintf(stderr, "usage: su [%s] [login]\n",
+ ARGSTR);
+ exit(1);
+ }
+ argv += optind;
+
+ errno = 0;
+ prio = getpriority(PRIO_PROCESS, 0);
+ if (errno)
+ prio = 0;
+ (void)setpriority(PRIO_PROCESS, 0, -2);
+ openlog("su", LOG_CONS, 0);
+
+ /* get current login name and shell */
+ ruid = getuid();
+ username = getlogin();
+ if (username == NULL || (pwd = getpwnam(username)) == NULL ||
+ pwd->pw_uid != ruid)
+ pwd = getpwuid(ruid);
+ if (pwd == NULL) {
+ fprintf(stderr, "su: who are you?\n");
+ exit(1);
+ }
+ username = strdup(pwd->pw_name);
+ if (asme)
+ if (pwd->pw_shell && *pwd->pw_shell)
+ shell = strcpy(shellbuf, pwd->pw_shell);
+ else {
+ shell = _PATH_BSHELL;
+ iscsh = NO;
+ }
+
+ /* get target login information, default to root */
+ user = *argv ? *argv : "root";
+ if ((pwd = getpwnam(user)) == NULL) {
+ fprintf(stderr, "su: unknown login %s\n", user);
+ exit(1);
+ }
+
+ if (ruid) {
+#ifdef KERBEROS
+ if (!use_kerberos || kerberos(username, user, pwd->pw_uid))
+#endif
+ {
+ /* only allow those in group zero to su to root. */
+ if (pwd->pw_uid == 0 && (gr = getgrgid((gid_t)0)))
+ for (g = gr->gr_mem;; ++g) {
+ if (!*g) {
+ (void)fprintf(stderr,
+ "su: you are not in the correct group to su %s.\n",
+ user);
+ exit(1);
+ }
+ if (!strcmp(username, *g))
+ break;
+ }
+ /* if target requires a password, verify it */
+ if (*pwd->pw_passwd) {
+ p = getpass("Password:");
+#ifdef DES
+ if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
+#else
+ if (strcmp(pwd->pw_passwd, p)) {
+#endif
+ fprintf(stderr, "Sorry\n");
+ syslog(LOG_AUTH|LOG_WARNING,
+ "BAD SU %s to %s%s", username,
+ user, ontty());
+ exit(1);
+ }
+ }
+ }
+ }
+
+ if (asme) {
+ /* if asme and non-standard target shell, must be root */
+ if (!chshell(pwd->pw_shell) && ruid) {
+ (void)fprintf(stderr,
+ "su: permission denied (shell).\n");
+ exit(1);
+ }
+ } else if (pwd->pw_shell && *pwd->pw_shell) {
+ shell = pwd->pw_shell;
+ iscsh = UNSET;
+ } else {
+ shell = _PATH_BSHELL;
+ iscsh = NO;
+ }
+
+ /* if we're forking a csh, we want to slightly muck the args */
+ if (iscsh == UNSET) {
+ if (p = rindex(shell, '/'))
+ ++p;
+ else
+ p = shell;
+ iscsh = strcmp(p, "csh") ? NO : YES;
+ }
+
+ /* set permissions */
+ if (setgid(pwd->pw_gid) < 0) {
+ perror("su: setgid");
+ exit(1);
+ }
+ if (initgroups(user, pwd->pw_gid)) {
+ (void)fprintf(stderr, "su: initgroups failed.\n");
+ exit(1);
+ }
+ if (setuid(pwd->pw_uid) < 0) {
+ perror("su: setuid");
+ exit(1);
+ }
+
+ if (!asme) {
+ if (asthem) {
+ p = getenv("TERM");
+ cleanenv[0] = _PATH_DEFPATH;
+ cleanenv[1] = NULL;
+ environ = cleanenv;
+ (void)setenv("TERM", p, 1);
+ if (chdir(pwd->pw_dir) < 0) {
+ fprintf(stderr, "su: no directory\n");
+ exit(1);
+ }
+ }
+ if (asthem || pwd->pw_uid)
+ (void)setenv("USER", pwd->pw_name, 1);
+ (void)setenv("HOME", pwd->pw_dir, 1);
+ (void)setenv("SHELL", shell, 1);
+ }
+
+ if (iscsh == YES) {
+ if (fastlogin)
+ *np-- = "-f";
+ if (asme)
+ *np-- = "-m";
+ }
+
+ /* csh strips the first character... */
+ *np = asthem ? "-su" : iscsh == YES ? "_su" : "su";
+
+ if (ruid != 0)
+ syslog(LOG_NOTICE|LOG_AUTH, "%s to %s%s",
+ username, user, ontty());
+
+ (void)setpriority(PRIO_PROCESS, 0, prio);
+
+ execv(shell, np);
+ (void)fprintf(stderr, "su: %s not found.\n", shell);
+ exit(1);
+}
+
+chshell(sh)
+ char *sh;
+{
+ register char *cp;
+ char *getusershell();
+
+ while ((cp = getusershell()) != NULL)
+ if (!strcmp(cp, sh))
+ return (1);
+ return (0);
+}
+
+char *
+ontty()
+{
+ char *p, *ttyname();
+ static char buf[MAXPATHLEN + 4];
+
+ buf[0] = 0;
+ if (p = ttyname(STDERR_FILENO))
+ sprintf(buf, " on %s", p);
+ return (buf);
+}
+
+#ifdef KERBEROS
+kerberos(username, user, uid)
+ char *username, *user;
+ int uid;
+{
+ extern char *krb_err_txt[];
+ KTEXT_ST ticket;
+ AUTH_DAT authdata;
+ struct hostent *hp;
+ register char *p;
+ int kerno;
+ u_long faddr;
+ char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN];
+ char hostname[MAXHOSTNAMELEN], savehost[MAXHOSTNAMELEN];
+ char *ontty(), *krb_get_phost();
+
+ if (krb_get_lrealm(lrealm, 1) != KSUCCESS)
+ return (1);
+ if (koktologin(username, lrealm, user) && !uid) {
+ (void)fprintf(stderr, "kerberos su: not in %s's ACL.\n", user);
+ return (1);
+ }
+ (void)sprintf(krbtkfile, "%s_%s_%d", TKT_ROOT, user, getuid());
+
+ (void)setenv("KRBTKFILE", krbtkfile, 1);
+ (void)krb_set_tkt_string(krbtkfile);
+ /*
+ * Set real as well as effective ID to 0 for the moment,
+ * to make the kerberos library do the right thing.
+ */
+ if (setuid(0) < 0) {
+ perror("su: setuid");
+ return (1);
+ }
+
+ /*
+ * Little trick here -- if we are su'ing to root,
+ * we need to get a ticket for "xxx.root", where xxx represents
+ * the name of the person su'ing. Otherwise (non-root case),
+ * we need to get a ticket for "yyy.", where yyy represents
+ * the name of the person being su'd to, and the instance is null
+ *
+ * We should have a way to set the ticket lifetime,
+ * with a system default for root.
+ */
+ kerno = krb_get_pw_in_tkt((uid == 0 ? username : user),
+ (uid == 0 ? "root" : ""), lrealm,
+ "krbtgt", lrealm, DEFAULT_TKT_LIFE, 0);
+
+ if (kerno != KSUCCESS) {
+ if (kerno == KDC_PR_UNKNOWN) {
+ fprintf(stderr, "principal unknown: %s.%s@%s\n",
+ (uid == 0 ? username : user),
+ (uid == 0 ? "root" : ""), lrealm);
+ return (1);
+ }
+ (void)fprintf(stderr, "su: unable to su: %s\n",
+ krb_err_txt[kerno]);
+ syslog(LOG_NOTICE|LOG_AUTH,
+ "BAD Kerberos SU: %s to %s%s: %s",
+ username, user, ontty(), krb_err_txt[kerno]);
+ return (1);
+ }
+
+ if (chown(krbtkfile, uid, -1) < 0) {
+ perror("su: chown:");
+ (void)unlink(krbtkfile);
+ return (1);
+ }
+
+ (void)setpriority(PRIO_PROCESS, 0, -2);
+
+ if (gethostname(hostname, sizeof(hostname)) == -1) {
+ perror("su: gethostname");
+ dest_tkt();
+ return (1);
+ }
+
+ (void)strncpy(savehost, krb_get_phost(hostname), sizeof(savehost));
+ savehost[sizeof(savehost) - 1] = '\0';
+
+ kerno = krb_mk_req(&ticket, "rcmd", savehost, lrealm, 33);
+
+ if (kerno == KDC_PR_UNKNOWN) {
+ (void)fprintf(stderr, "Warning: TGT not verified.\n");
+ syslog(LOG_NOTICE|LOG_AUTH,
+ "%s to %s%s, TGT not verified (%s); %s.%s not registered?",
+ username, user, ontty(), krb_err_txt[kerno],
+ "rcmd", savehost);
+ } else if (kerno != KSUCCESS) {
+ (void)fprintf(stderr, "Unable to use TGT: %s\n",
+ krb_err_txt[kerno]);
+ syslog(LOG_NOTICE|LOG_AUTH, "failed su: %s to %s%s: %s",
+ username, user, ontty(), krb_err_txt[kerno]);
+ dest_tkt();
+ return (1);
+ } else {
+ if (!(hp = gethostbyname(hostname))) {
+ (void)fprintf(stderr, "su: can't get addr of %s\n",
+ hostname);
+ dest_tkt();
+ return (1);
+ }
+ (void)bcopy((char *)hp->h_addr, (char *)&faddr, sizeof(faddr));
+
+ if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr,
+ &authdata, "")) != KSUCCESS) {
+ (void)fprintf(stderr,
+ "su: unable to verify rcmd ticket: %s\n",
+ krb_err_txt[kerno]);
+ syslog(LOG_NOTICE|LOG_AUTH,
+ "failed su: %s to %s%s: %s", username,
+ user, ontty(), krb_err_txt[kerno]);
+ dest_tkt();
+ return (1);
+ }
+ }
+ return (0);
+}
+
+koktologin(name, realm, toname)
+ char *name, *realm, *toname;
+{
+ register AUTH_DAT *kdata;
+ AUTH_DAT kdata_st;
+
+ kdata = &kdata_st;
+ bzero((caddr_t) kdata, sizeof(*kdata));
+ (void)strcpy(kdata->pname, name);
+ (void)strcpy(kdata->pinst,
+ ((strcmp(toname, "root") == 0) ? "root" : ""));
+ (void)strcpy(kdata->prealm, realm);
+ return (kuserok(kdata, toname));
+}
+#endif
projects / unix-history / commitdiff