1 files changed, 399 insertions, 0 deletions

diff --git a/usr.bin/su/su.c b/usr.bin/su/su.c
new file mode 100644
index 0000000..f06ef2f
--- /dev/null
+++ b/usr.bin/su/su.c
@@ -0,0 +1,399 @@
+/*
+ * Copyright (c) 1988, 1993, 1994
+ *	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
+static char copyright[] =
+"@(#) Copyright (c) 1988, 1993, 1994\n\
+	The Regents of the University of California.  All rights reserved.\n";
+#endif /* not lint */
+
+#ifndef lint
+static char sccsid[] = "@(#)su.c	8.3 (Berkeley) 4/2/94";
+#endif /* not lint */
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/resource.h>
+
+#include <err.h>
+#include <errno.h>
+#include <grp.h>
+#include <paths.h>
+#include <pwd.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <syslog.h>
+#include <unistd.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
+
+char   *ontty __P((void));
+int	chshell __P((char *));
+
+int
+main(argc, argv)
+	int argc;
+	char **argv;
+{
+	extern char **environ;
+	struct passwd *pwd;
+	char *p, **g, *user, *shell, *username, *cleanenv[2], *nargv[4], **np;
+	struct group *gr;
+	uid_t ruid;
+	int asme, ch, asthem, fastlogin, prio;
+	enum { UNSET, YES, NO } iscsh = UNSET;
+	char shellbuf[MAXPATHLEN];
+
+	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)
+		errx(1, "who are you?");
+	username = strdup(pwd->pw_name);
+	if (username == NULL)
+		err(1, NULL);
+	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)
+					errx(1,
+			    "you are not in the correct group to su %s.",
+					    user);
+				if (strcmp(username, *g) == 0)
+					break;
+		}
+		/* if target requires a password, verify it */
+		if (*pwd->pw_passwd) {
+			p = getpass("Password:");
+			if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
+				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)
+			errx(1, "permission denied (shell).");
+	} 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 = strrchr(shell, '/'))
+			++p;
+		else
+			p = shell;
+		iscsh = strcmp(p, "csh") ? NO : YES;
+	}
+
+	/* set permissions */
+	if (setgid(pwd->pw_gid) < 0)
+		err(1, "setgid");
+	if (initgroups(user, pwd->pw_gid))
+		errx(1, "initgroups failed");
+	if (setuid(pwd->pw_uid) < 0)
+		err(1, "setuid");
+
+	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)
+				errx(1, "no directory");
+		}
+		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);
+	err(1, "%s", shell);
+}
+
+int
+chshell(sh)
+	char *sh;
+{
+	char *cp;
+
+	while ((cp = getusershell()) != NULL)
+		if (strcmp(cp, sh) == 0)
+			return (1);
+	return (0);
+}
+
+char *
+ontty()
+{
+	char *p;
+	static char buf[MAXPATHLEN + 4];
+
+	buf[0] = 0;
+	if (p = ttyname(STDERR_FILENO))
+		snprintf(buf, sizeof(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;
+	char *p;
+	int kerno;
+	u_long faddr;
+	char lrealm[REALM_SZ], krbtkfile[MAXPATHLEN];
+	char hostname[MAXHOSTNAMELEN], savehost[MAXHOSTNAMELEN];
+	char *krb_get_phost();
+
+	if (krb_get_lrealm(lrealm, 1) != KSUCCESS)
+		return (1);
+	if (koktologin(username, lrealm, user) && !uid) {
+		warnx("kerberos: not in %s's ACL.", 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) {
+		warn("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) {
+			warnx("kerberos: principal unknown: %s.%s@%s",
+				(uid == 0 ? username : user),
+				(uid == 0 ? "root" : ""), lrealm);
+			return (1);
+		}
+		warnx("kerberos: unable to su: %s", 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) {
+		warn("chown");
+		(void)unlink(krbtkfile);
+		return (1);
+	}
+
+	(void)setpriority(PRIO_PROCESS, 0, -2);
+
+	if (gethostname(hostname, sizeof(hostname)) == -1) {
+		warn("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) {
+		warnx("Warning: TGT not verified.");
+		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) {
+		warnx("Unable to use TGT: %s", 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))) {
+			warnx("can't get addr of %s", hostname);
+			dest_tkt();
+			return (1);
+		}
+		memmove((char *)&faddr, (char *)hp->h_addr, sizeof(faddr));
+
+		if ((kerno = krb_rd_req(&ticket, "rcmd", savehost, faddr,
+		    &authdata, "")) != KSUCCESS) {
+			warnx("kerberos: 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;
+{
+	AUTH_DAT *kdata;
+	AUTH_DAT kdata_st;
+
+	kdata = &kdata_st;
+	memset((char *)kdata, 0, 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