break out special local mail processing (e.g., mapping to the
[unix-history] / usr / src / usr.bin / su / su.c
index 073d24d..7f1c6cd 100644 (file)
@@ -1,73 +1,90 @@
 /*
 /*
- * Copyright (c) 1988 The Regents of the University of California.
- * All rights reserved.
+ * Copyright (c) 1988, 1993, 1994
+ *     The Regents of the University of California.  All rights reserved.
  *
  *
- * Redistribution and use in source and binary forms are permitted
- * provided that the above copyright notice and this paragraph are
- * duplicated in all such forms and that any documentation,
- * advertising materials, and other materials related to such
- * distribution and use acknowledge that the software was developed
- * by the University of California, Berkeley.  The name of the
- * University may not be used to endorse or promote products derived
- * from this software without specific prior written permission.
- * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
- * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
- * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
+ * %sccs.include.redist.c%
  */
 
 #ifndef lint
  */
 
 #ifndef lint
-char copyright[] =
-"@(#) Copyright (c) 1988 The Regents of the University of California.\n\
- All rights reserved.\n";
+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
 #endif /* not lint */
 
 #ifndef lint
-static char sccsid[] = "@(#)su.c       5.12 (Berkeley) %G%";
+static char sccsid[] = "@(#)su.c       8.3 (Berkeley) %G%";
 #endif /* not lint */
 
 #include <sys/param.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #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 <err.h>
+#include <errno.h>
 #include <grp.h>
 #include <grp.h>
-#include "pathnames.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;
 main(argc, argv)
        int argc;
        char **argv;
 {
        extern char **environ;
-       extern int errno, optind;
-       register struct passwd *pwd;
-       register char *p, **g;
+       struct passwd *pwd;
+       char *p, **g, *user, *shell, *username, *cleanenv[2], *nargv[4], **np;
        struct group *gr;
        struct group *gr;
-       uid_t ruid, getuid();
-       int asme, ch, fulllogin, fastlogin, prio;
+       uid_t ruid;
+       int asme, ch, asthem, fastlogin, prio;
        enum { UNSET, YES, NO } iscsh = UNSET;
        enum { UNSET, YES, NO } iscsh = UNSET;
-       char *user, *shell, *username, *cleanenv[2], *nargv[4], **np;
-       char namebuf[50], shellbuf[MAXPATHLEN];
-       char *crypt(), *getpass(), *getenv(), *getlogin(), *rindex(), *strcpy();
+       char shellbuf[MAXPATHLEN];
 
        np = &nargv[3];
        *np-- = NULL;
 
        np = &nargv[3];
        *np-- = NULL;
-       asme = fulllogin = fastlogin = 0;
-       while ((ch = getopt(argc, argv, "-flm")) != EOF)
+       asme = asthem = fastlogin = 0;
+       while ((ch = getopt(argc, argv, ARGSTR)) != EOF)
                switch((char)ch) {
                switch((char)ch) {
+#ifdef KERBEROS
+               case 'K':
+                       use_kerberos = 0;
+                       break;
+#endif
                case 'f':
                        fastlogin = 1;
                        break;
                case '-':
                case 'l':
                case 'f':
                        fastlogin = 1;
                        break;
                case '-':
                case 'l':
-                       fulllogin = 1;
+                       asme = 0;
+                       asthem = 1;
                        break;
                case 'm':
                        asme = 1;
                        break;
                case 'm':
                        asme = 1;
+                       asthem = 0;
                        break;
                case '?':
                default:
                        break;
                case '?':
                default:
-                       fprintf(stderr, "usage: su [-flm] [login]\n");
+                       (void)fprintf(stderr, "usage: su [%s] [login]\n",
+                           ARGSTR);
                        exit(1);
                }
        argv += optind;
                        exit(1);
                }
        argv += optind;
@@ -77,13 +94,19 @@ main(argc, argv)
        if (errno)
                prio = 0;
        (void)setpriority(PRIO_PROCESS, 0, -2);
        if (errno)
                prio = 0;
        (void)setpriority(PRIO_PROCESS, 0, -2);
+       openlog("su", LOG_CONS, 0);
 
        /* get current login name and shell */
 
        /* get current login name and shell */
-       if ((pwd = getpwuid(ruid = getuid())) == NULL) {
-               fprintf(stderr, "su: who are you?\n");
-               exit(1);
-       }
-       username = strcpy(namebuf, pwd->pw_name);
+       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);
        if (asme)
                if (pwd->pw_shell && *pwd->pw_shell)
                        shell = strcpy(shellbuf,  pwd->pw_shell);
@@ -92,43 +115,47 @@ main(argc, argv)
                        iscsh = NO;
                }
 
                        iscsh = NO;
                }
 
-       /* get target login information */
+       /* 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);
        }
 
        user = *argv ? *argv : "root";
        if ((pwd = getpwnam(user)) == NULL) {
                fprintf(stderr, "su: unknown login %s\n", user);
                exit(1);
        }
 
-       /* 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) {
-                               fprintf(stderr, "su: you are not in the correct group to su %s.\n", user);
+       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);
                        }
                                exit(1);
                        }
-                       if (!strcmp(username, *g))
-                               break;
-               }
-
-       /* if target requires a password, verify it */
-       if (ruid && *pwd->pw_passwd) {
-               p = getpass("Password:");
-               if (strcmp(pwd->pw_passwd, crypt(p, pwd->pw_passwd))) {
-                       fprintf(stderr, "Sorry\n");
-                       if (pwd->pw_uid == 0)
-                               syslog(LOG_CRIT|LOG_AUTH, "su: BAD SU %s on %s", username, ttyname(2));
-                       exit(1);
                }
                }
+           }
        }
 
        if (asme) {
                /* if asme and non-standard target shell, must be root */
        }
 
        if (asme) {
                /* if asme and non-standard target shell, must be root */
-               if (!chshell(pwd->pw_shell) && ruid) {
-                       fprintf(stderr, "su: Permission denied.\n");
-                       exit(1);
-               }
-       }
-       else if (pwd->pw_shell && *pwd->pw_shell) {
+               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 = pwd->pw_shell;
                iscsh = UNSET;
        } else {
@@ -138,7 +165,7 @@ main(argc, argv)
 
        /* if we're forking a csh, we want to slightly muck the args */
        if (iscsh == UNSET) {
 
        /* if we're forking a csh, we want to slightly muck the args */
        if (iscsh == UNSET) {
-               if (p = rindex(shell, '/'))
+               if (p = strrchr(shell, '/'))
                        ++p;
                else
                        p = shell;
                        ++p;
                else
                        p = shell;
@@ -146,32 +173,24 @@ main(argc, argv)
        }
 
        /* set permissions */
        }
 
        /* set permissions */
-       if (setgid(pwd->pw_gid) < 0) {
-               perror("su: setgid");
-               exit(1);
-       }
-       if (initgroups(user, pwd->pw_gid)) {
-               fprintf(stderr, "su: initgroups failed\n");
-               exit(1);
-       }
-       if (setuid(pwd->pw_uid) < 0) {
-               perror("su: setuid");
-               exit(1);
-       }
+       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 (!asme) {
-               if (fulllogin) {
+               if (asthem) {
                        p = getenv("TERM");
                        p = getenv("TERM");
-                       cleanenv[0] = _PATH_SEARCHPATH;
+                       cleanenv[0] = _PATH_DEFPATH;
                        cleanenv[1] = NULL;
                        environ = cleanenv;
                        (void)setenv("TERM", p, 1);
                        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 (chdir(pwd->pw_dir) < 0)
+                               errx(1, "no directory");
                }
                }
-               if (fulllogin || pwd->pw_uid)
+               if (asthem || pwd->pw_uid)
                        (void)setenv("USER", pwd->pw_name, 1);
                (void)setenv("HOME", pwd->pw_dir, 1);
                (void)setenv("SHELL", shell, 1);
                        (void)setenv("USER", pwd->pw_name, 1);
                (void)setenv("HOME", pwd->pw_dir, 1);
                (void)setenv("SHELL", shell, 1);
@@ -185,26 +204,170 @@ main(argc, argv)
        }
 
        /* csh strips the first character... */
        }
 
        /* csh strips the first character... */
-       *np = fulllogin ? "-su" : iscsh == YES ? "_su" : "su";
+       *np = asthem ? "-su" : iscsh == YES ? "_su" : "su";
 
 
-       if (pwd->pw_uid == 0)
-               syslog(LOG_NOTICE|LOG_AUTH, "su: %s on %s",
-                   username, ttyname(2));
+       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)setpriority(PRIO_PROCESS, 0, prio);
 
        execv(shell, np);
-       fprintf(stderr, "su: no shell.\n");
-       exit(1);
+       err(1, "%s", shell);
 }
 
 }
 
+int
 chshell(sh)
        char *sh;
 {
 chshell(sh)
        char *sh;
 {
-       char *cp, *getusershell();
+       char *cp;
 
        while ((cp = getusershell()) != NULL)
 
        while ((cp = getusershell()) != NULL)
-               if (!strcmp(cp, sh))
-                       return(1);
-       return(0);
+               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