break out special local mail processing (e.g., mapping to the

[unix-history] / usr / src / usr.bin / su / su.c

diff --git a/usr/src/usr.bin/su/su.c b/usr/src/usr.bin/su/su.c
index 1b14749..7f1c6cd 100644 (file)
--- a/usr/src/usr.bin/su/su.c
+++ b/usr/src/usr.bin/su/su.c
@@ -1,105 +1,373 @@
-static char *sccsid = "@(#)su.c        4.3 (Berkeley) 4.3";
-#include <stdio.h>
+/*
+ * Copyright (c) 1988, 1993, 1994
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * %sccs.include.redist.c%
+ */
+
+#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) %G%";
+#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 <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"

 
 

-struct passwd *pwd,*getpwnam();
-char   *crypt();
-char   *getpass();
+int use_kerberos = 1;
+#else
+#define        ARGSTR  "-flm"
+#endif

 
 

-main(argc,argv)
-int    argc;
-char   **argv;
+char   *ontty __P((void));
+int    chshell __P((char *));
+
+int
+main(argc, argv)
+       int argc;
+       char **argv;

 {
 {

-       char *nptr;
-       char *password;
-       int badsw = 0;
-       char *shell = "/bin/sh";
-       int niced = 0;
-
-       if(argc > 1)
-               nptr = argv[1];
-       else {
-               nptr = "root";
-               nice(-4);
-               niced = -4;
-       }
-       if((pwd=getpwnam(nptr)) == NULL) {
-               printf("Unknown id: %s\n",nptr);
+       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);
        }
                exit(1);
        }

-       if(pwd->pw_passwd[0] == '\0' || getuid() == 0)
-               goto ok;
-       password = getpass("Password:");
-       if(badsw || (strcmp(pwd->pw_passwd, crypt(password, pwd->pw_passwd)) != 0)) {
-bad:
-               printf("Sorry\n");
-               if(pwd->pw_uid == 0) {
-                       FILE *console = fopen("/dev/console", "w");
-                       if (console != NULL) {
-                               fprintf(console, "BADSU: %s %s\r\n", getlogin(), ttyname(2));
-                               fclose(console);
+
+       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(2);
+           }
+       }
+
+       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;

        }
        }

-ok:
-       endpwent();
-       if(pwd->pw_uid == 0) {
-               FILE *console = fopen("/dev/console", "w");
-               if (console != NULL) {
-                       fprintf(console, "SU: %s %s\r\n", getlogin(), ttyname(2));
-                       fclose(console);
+
+       /* 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);

        }
        }

-       setgid(pwd->pw_gid);
-       initgroups(nptr, pwd->pw_gid);
-       setuid(pwd->pw_uid);
-       if (pwd->pw_shell && *pwd->pw_shell)
-               shell = pwd->pw_shell;
-       homeis(pwd->pw_dir);
-       shellis(shell);
-       nice(-niced);
-       execl(shell, "su", 0);
-       printf("No shell\n");
-       exit(3);
+
+       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);

 }
 
 }
 

-char   **environ;
+int
+chshell(sh)
+       char *sh;
+{
+       char *cp;
+
+       while ((cp = getusershell()) != NULL)
+               if (strcmp(cp, sh) == 0)
+                       return (1);
+       return (0);
+}

 
 

-homeis(hp)
-       char *hp;
+char *
+ontty()

 {
 {

-       register char *cp, *dp;
-       register char **ep = environ;
-       static char homebuf[128];
-
-       while (dp = *ep++) {
-               for (cp = "HOME"; *cp == *dp && *cp; cp++, dp++)
-                       continue;
-               if (*cp == 0 && (*dp == '=' || *dp == 0)) {
-                       strcpy(homebuf, "HOME=");
-                       strcat(homebuf, hp);
-                       *--ep = homebuf;
-                       return;
-               }
-       }
+       char *p;
+       static char buf[MAXPATHLEN + 4];
+
+       buf[0] = 0;
+       if (p = ttyname(STDERR_FILENO))
+               snprintf(buf, sizeof(buf), " on %s", p);
+       return (buf);

 }
 
 }
 

-shellis(sp)
-       char *sp;
+#ifdef KERBEROS
+kerberos(username, user, uid)
+       char *username, *user;
+       int uid;

 {
 {

-       register char *cp, *dp;
-       register char **ep = environ;
-       static char shellbuf[128];
-
-       while (dp = *ep++) {
-               for (cp = "SHELL"; *cp == *dp && *cp; cp++, dp++)
-                       continue;
-               if (*cp == 0 && (*dp == '=' || *dp == 0)) {
-                       strcpy(shellbuf, "SHELL=");
-                       strcat(shellbuf, sp);
-                       *--ep = shellbuf;
-                       return;
+       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