add protection against masquerading Kerberos server

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

diff --git a/usr/src/usr.bin/login/login.c b/usr/src/usr.bin/login/login.c
index d2c21a9..c1ac218 100644 (file)
--- a/usr/src/usr.bin/login/login.c
+++ b/usr/src/usr.bin/login/login.c
@@ -22,17 +22,18 @@ char copyright[] =
 #endif /* not lint */
 
 #ifndef lint
 #endif /* not lint */
 
 #ifndef lint

-static char sccsid[] = "@(#)login.c    5.35 (Berkeley) %G%";
+static char sccsid[] = "@(#)login.c    5.41 (Berkeley) %G%";

 #endif /* not lint */
 
 /*
  * login [ name ]
 #endif /* not lint */
 
 /*
  * login [ name ]

+ * login -r hostname   (for rlogind)

  * login -h hostname   (for telnetd, etc.)
  * login -f name       (for pre-authenticated login: datakit, xterm, etc.)
  */
 
 #include <sys/param.h>
  * login -h hostname   (for telnetd, etc.)
  * login -f name       (for pre-authenticated login: datakit, xterm, etc.)
  */
 
 #include <sys/param.h>

-#include <sys/quota.h>
+#include <ufs/quota.h>

 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/resource.h>
 #include <sys/stat.h>
 #include <sys/time.h>
 #include <sys/resource.h>


@@ -41,7 +42,6 @@ static char sccsid[] = "@(#)login.c   5.35 (Berkeley) %G%";
 
 #include <utmp.h>
 #include <signal.h>
 
 #include <utmp.h>
 #include <signal.h>

-#include <lastlog.h>

 #include <errno.h>
 #include <ttyent.h>
 #include <syslog.h>
 #include <errno.h>
 #include <ttyent.h>
 #include <syslog.h>


@@ -50,6 +50,7 @@ static char sccsid[] = "@(#)login.c   5.35 (Berkeley) %G%";
 #include <setjmp.h>
 #include <stdio.h>
 #include <strings.h>
 #include <setjmp.h>
 #include <stdio.h>
 #include <strings.h>

+#include <tzfile.h>

 #include "pathnames.h"
 
 #define        TTYGRPNAME      "tty"           /* name of group to own ttys */
 #include "pathnames.h"
 
 #define        TTYGRPNAME      "tty"           /* name of group to own ttys */


@@ -93,10 +94,11 @@ main(argc, argv)
        struct group *gr;
        register int ch;
        register char *p;
        struct group *gr;
        register int ch;
        register char *p;

-       int ask, fflag, hflag, pflag, cnt;
+       int ask, fflag, hflag, pflag, rflag, cnt;

        int quietlog, passwd_req, ioctlval, timedout();
        char *domain, *salt, *envinit[1], *ttyn, *pp;
        int quietlog, passwd_req, ioctlval, timedout();
        char *domain, *salt, *envinit[1], *ttyn, *pp;

-       char tbuf[MAXPATHLEN + 2];
+       char tbuf[MAXPATHLEN + 2], tname[sizeof(_PATH_TTY) + 10];
+       char localhost[MAXHOSTNAMELEN];

        char *ctime(), *ttyname(), *stypeof(), *crypt(), *getpass();
        time_t time();
        off_t lseek();
        char *ctime(), *ttyname(), *stypeof(), *crypt(), *getpass();
        time_t time();
        off_t lseek();


@@ -110,26 +112,40 @@ main(argc, argv)
 
        /*
         * -p is used by getty to tell login not to destroy the environment
 
        /*
         * -p is used by getty to tell login not to destroy the environment

+        * -r is used by rlogind to cause the autologin protocol;

         * -f is used to skip a second login authentication 
         * -h is used by other servers to pass the name of the remote
         *    host to login so that it may be placed in utmp and wtmp
         */
         * -f is used to skip a second login authentication 
         * -h is used by other servers to pass the name of the remote
         *    host to login so that it may be placed in utmp and wtmp
         */

-       (void)gethostname(tbuf, sizeof(tbuf));
-       domain = index(tbuf, '.');
+       domain = NULL;
+       if (gethostname(localhost, sizeof(localhost)) < 0)
+               syslog(LOG_ERR, "couldn't get local hostname: %m");
+       else
+               domain = index(localhost, '.');

 
 

-       fflag = hflag = pflag = 0;
+       fflag = hflag = pflag = rflag = 0;

        passwd_req = 1;
        passwd_req = 1;

-       while ((ch = getopt(argc, argv, "fh:p")) != EOF)
+       while ((ch = getopt(argc, argv, "fh:pr:")) != EOF)

                switch (ch) {
                case 'f':
                switch (ch) {
                case 'f':

+                       if (rflag) {
+                               fprintf(stderr,
+                                   "login: only one of -r and -f allowed.\n");
+                               exit(1);
+                       }

                        fflag = 1;
                        break;
                case 'h':
                        if (getuid()) {
                        fflag = 1;
                        break;
                case 'h':
                        if (getuid()) {

-                               fprintf(stderr,
+                               (void)fprintf(stderr,

                                    "login: -h for super-user only.\n");
                                exit(1);
                        }
                                    "login: -h for super-user only.\n");
                                exit(1);
                        }

+                       if (rflag) {
+                               fprintf(stderr,
+                                   "login: only one of -r and -h allowed.\n");
+                               exit(1);
+                       }

                        hflag = 1;
                        if (domain && (p = index(optarg, '.')) &&
                            strcasecmp(p, domain) == 0)
                        hflag = 1;
                        if (domain && (p = index(optarg, '.')) &&
                            strcasecmp(p, domain) == 0)


@@ -139,9 +155,33 @@ main(argc, argv)
                case 'p':
                        pflag = 1;
                        break;
                case 'p':
                        pflag = 1;
                        break;

+               case 'r':
+                       if (hflag || fflag) {
+                               fprintf(stderr,
+                                   "login: -f and -h not allowed with -r.\n");
+                               exit(1);
+                       }
+                       if (getuid()) {
+                               fprintf(stderr,
+                                   "login: -r for super-user only.\n");
+                               exit(1);
+                       }
+                       /* "-r hostname" must be last args */
+                       if (optind != argc) {
+                               fprintf(stderr, "Syntax error.\n");
+                               exit(1);
+                       }
+                       rflag = 1;
+                       passwd_req = (doremotelogin(optarg) == -1);
+                       if (domain && (p = index(optarg, '.')) &&
+                           !strcmp(p, domain))
+                               *p = '\0';
+                       hostname = optarg;
+                       break;

                case '?':
                default:
                case '?':
                default:

-                       fprintf(stderr, "usage: login [-fp] [username]\n");
+                       (void)fprintf(stderr,
+                           "usage: login [-fp] [username]\n");

                        exit(1);
                }
        argc -= optind;
                        exit(1);
                }
        argc -= optind;


@@ -151,12 +191,21 @@ main(argc, argv)
                ask = 0;
        } else
                ask = 1;
                ask = 0;
        } else
                ask = 1;

+       if (rflag)
+               ask = 0;

 
        ioctlval = 0;
        (void)ioctl(0, TIOCLSET, &ioctlval);
        (void)ioctl(0, TIOCNXCL, 0);
        (void)fcntl(0, F_SETFL, ioctlval);
        (void)ioctl(0, TIOCGETP, &sgttyb);
 
        ioctlval = 0;
        (void)ioctl(0, TIOCLSET, &ioctlval);
        (void)ioctl(0, TIOCNXCL, 0);
        (void)fcntl(0, F_SETFL, ioctlval);
        (void)ioctl(0, TIOCGETP, &sgttyb);

+
+       /*
+        * If talking to an rlogin process, propagate the terminal type and
+        * baud rate across the network.
+        */
+       if (rflag)
+               doremoteterm(&sgttyb);

        sgttyb.sg_erase = CERASE;
        sgttyb.sg_kill = CKILL;
        (void)ioctl(0, TIOCSLTC, &ltc);
        sgttyb.sg_erase = CERASE;
        sgttyb.sg_kill = CKILL;
        (void)ioctl(0, TIOCSLTC, &ltc);


@@ -167,8 +216,10 @@ main(argc, argv)
                close(cnt);
 
        ttyn = ttyname(0);
                close(cnt);
 
        ttyn = ttyname(0);

-       if (ttyn == NULL || *ttyn == '\0')
-               ttyn = "/dev/tty??";
+       if (ttyn == NULL || *ttyn == '\0') {
+               (void)sprintf(tname, "%s??", _PATH_TTY);
+               ttyn = tname;
+       }

        if (tty = rindex(ttyn, '/'))
                ++tty;
        else
        if (tty = rindex(ttyn, '/'))
                ++tty;
        else


@@ -232,7 +283,7 @@ main(argc, argv)
                if (pwd && !strcmp(p, pwd->pw_passwd))
                        break;
 
                if (pwd && !strcmp(p, pwd->pw_passwd))
                        break;
 

-               printf("Login incorrect\n");
+               (void)printf("Login incorrect\n");

                failures++;
                /* we allow 10 tries, but after 3 we start backing off */
                if (++cnt > 3) {
                failures++;
                /* we allow 10 tries, but after 3 we start backing off */
                if (++cnt > 3) {


@@ -248,6 +299,9 @@ main(argc, argv)
        /* committed to login -- turn off timeout */
        (void)alarm((u_int)0);
 
        /* committed to login -- turn off timeout */
        (void)alarm((u_int)0);
 

+       /* paranoia... */
+       endpwent();
+

        /*
         * If valid so far and root is logging in, see if root logins on
         * this terminal are permitted.
        /*
         * If valid so far and root is logging in, see if root logins on
         * this terminal are permitted.


@@ -258,18 +312,18 @@ main(argc, argv)
                            hostname);
                else
                        syslog(LOG_NOTICE, "ROOT LOGIN REFUSED ON %s", tty);
                            hostname);
                else
                        syslog(LOG_NOTICE, "ROOT LOGIN REFUSED ON %s", tty);

-               printf("Login incorrect\n");
+               (void)printf("Login incorrect\n");

                sleepexit(1);
        }
 
        if (quota(Q_SETUID, pwd->pw_uid, 0, 0) < 0 && errno != EINVAL) {
                switch(errno) {
                case EUSERS:
                sleepexit(1);
        }
 
        if (quota(Q_SETUID, pwd->pw_uid, 0, 0) < 0 && errno != EINVAL) {
                switch(errno) {
                case EUSERS:

-                       fprintf(stderr,
+                       (void)fprintf(stderr,

                "Too many users logged on already.\nTry again later.\n");
                        break;
                case EPROCLIM:
                "Too many users logged on already.\nTry again later.\n");
                        break;
                case EPROCLIM:

-                       fprintf(stderr,
+                       (void)fprintf(stderr,

                            "You have too many processes running.\n");
                        break;
                default:
                            "You have too many processes running.\n");
                        break;
                default:


@@ -279,11 +333,11 @@ main(argc, argv)
        }
 
        if (chdir(pwd->pw_dir) < 0) {
        }
 
        if (chdir(pwd->pw_dir) < 0) {

-               printf("No directory %s!\n", pwd->pw_dir);
+               (void)printf("No directory %s!\n", pwd->pw_dir);

                if (chdir("/"))
                        exit(0);
                pwd->pw_dir = "/";
                if (chdir("/"))
                        exit(0);
                pwd->pw_dir = "/";

-               printf("Logging in with home = \"/\".\n");
+               (void)printf("Logging in with home = \"/\".\n");

        }
 
 #define        TWOWEEKS        (14*24*60*60)
        }
 
 #define        TWOWEEKS        (14*24*60*60)


@@ -315,23 +369,23 @@ main(argc, argv)
                (void)gettimeofday(&tp, (struct timezone *)NULL);
        if (pwd->pw_change)
                if (tp.tv_sec >= pwd->pw_change) {
                (void)gettimeofday(&tp, (struct timezone *)NULL);
        if (pwd->pw_change)
                if (tp.tv_sec >= pwd->pw_change) {

-                       printf("Sorry -- your password has expired.\n");
+                       (void)printf("Sorry -- your password has expired.\n");

                        sleepexit(1);
                }
                        sleepexit(1);
                }

-               else if (tp.tv_sec - pwd->pw_change < TWOWEEKS) {
+               else if (tp.tv_sec - pwd->pw_change < TWOWEEKS && !quietlog) {

                        ttp = localtime(&pwd->pw_change);
                        ttp = localtime(&pwd->pw_change);

-                       printf("Warning: your password expires on %s %d, 19%d\n",
-                           months[ttp->tm_mon], ttp->tm_mday, ttp->tm_year);
+                       (void)printf("Warning: your password expires on %s %d, %d\n",
+                           months[ttp->tm_mon], ttp->tm_mday, TM_YEAR_BASE + ttp->tm_year);

                }
        if (pwd->pw_expire)
                if (tp.tv_sec >= pwd->pw_expire) {
                }
        if (pwd->pw_expire)
                if (tp.tv_sec >= pwd->pw_expire) {

-                       printf("Sorry -- your account has expired.\n");
+                       (void)printf("Sorry -- your account has expired.\n");

                        sleepexit(1);
                }
                        sleepexit(1);
                }

-               else if (tp.tv_sec - pwd->pw_expire < TWOWEEKS) {
+               else if (tp.tv_sec - pwd->pw_expire < TWOWEEKS && !quietlog) {

                        ttp = localtime(&pwd->pw_expire);
                        ttp = localtime(&pwd->pw_expire);

-                       printf("Warning: your account expires on %s %d, 19%d\n",
-                           months[ttp->tm_mon], ttp->tm_mday, ttp->tm_year);
+                       (void)printf("Warning: your account expires on %s %d, %d\n",
+                           months[ttp->tm_mon], ttp->tm_mday, TM_YEAR_BASE + ttp->tm_year);

                }
 
        /* nothing else left to fail -- really log in */
                }
 
        /* nothing else left to fail -- really log in */


@@ -347,10 +401,9 @@ main(argc, argv)
                login(&utmp);
        }
 
                login(&utmp);
        }
 

-       quietlog = access(_PATH_HUSHLOGIN, F_OK) == 0;

        dolastlog(quietlog);
 
        dolastlog(quietlog);
 

-       if (!hflag) {                                   /* XXX */
+       if (!hflag && !rflag) {                                 /* XXX */

                static struct winsize win = { 0, 0, 0, 0 };
 
                (void)ioctl(0, TIOCSWINSZ, &win);
                static struct winsize win = { 0, 0, 0, 0 };
 
                (void)ioctl(0, TIOCSWINSZ, &win);


@@ -364,12 +417,11 @@ main(argc, argv)
        initgroups(username, pwd->pw_gid);
 
        quota(Q_DOWARN, pwd->pw_uid, (dev_t)-1, 0);
        initgroups(username, pwd->pw_gid);
 
        quota(Q_DOWARN, pwd->pw_uid, (dev_t)-1, 0);

-       (void)setuid(pwd->pw_uid);

 
        if (*pwd->pw_shell == '\0')
                pwd->pw_shell = _PATH_BSHELL;
        /* turn on new line discipline for the csh */
 
        if (*pwd->pw_shell == '\0')
                pwd->pw_shell = _PATH_BSHELL;
        /* turn on new line discipline for the csh */

-       else if (!strcmp(pwd->pw_shell, "/bin/csh")) {
+       else if (!strcmp(pwd->pw_shell, _PATH_CSHELL)) {

                ioctlval = NTTYDISC;
                (void)ioctl(0, TIOCSETD, &ioctlval);
        }
                ioctlval = NTTYDISC;
                (void)ioctl(0, TIOCSETD, &ioctlval);
        }


@@ -383,7 +435,7 @@ main(argc, argv)
                strncpy(term, stypeof(tty), sizeof(term));
        (void)setenv("TERM", term, 0);
        (void)setenv("USER", pwd->pw_name, 1);
                strncpy(term, stypeof(tty), sizeof(term));
        (void)setenv("TERM", term, 0);
        (void)setenv("USER", pwd->pw_name, 1);

-       (void)setenv("PATH", "/usr/ucb:/bin:/usr/bin:", 0);
+       (void)setenv("PATH", _PATH_DEFPATH, 0);

 
        if (tty[sizeof("tty")-1] == 'd')
                syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);
 
        if (tty[sizeof("tty")-1] == 'd')
                syslog(LOG_INFO, "DIALUP %s, %s", tty, pwd->pw_name);


@@ -400,7 +452,7 @@ main(argc, argv)
                motd();
                (void)sprintf(tbuf, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
                if (stat(tbuf, &st) == 0 && st.st_size != 0)
                motd();
                (void)sprintf(tbuf, "%s/%s", _PATH_MAILDIR, pwd->pw_name);
                if (stat(tbuf, &st) == 0 && st.st_size != 0)

-                       printf("You have %smail.\n",
+                       (void)printf("You have %smail.\n",

                            (st.st_mtime > st.st_atime) ? "new " : "");
        }
 
                            (st.st_mtime > st.st_atime) ? "new " : "");
        }
 


@@ -412,9 +464,15 @@ main(argc, argv)
        tbuf[0] = '-';
        strcpy(tbuf + 1, (p = rindex(pwd->pw_shell, '/')) ?
            p + 1 : pwd->pw_shell);
        tbuf[0] = '-';
        strcpy(tbuf + 1, (p = rindex(pwd->pw_shell, '/')) ?
            p + 1 : pwd->pw_shell);

+
+       if (setlogname(pwd->pw_name, strlen(pwd->pw_name)) < 0)
+               syslog(LOG_ERR, "setlogname() failure: %m");
+
+       /* discard permissions last so can't get killed and drop core */
+       (void)setuid(pwd->pw_uid);
+

        execlp(pwd->pw_shell, tbuf, 0);
        execlp(pwd->pw_shell, tbuf, 0);

-       fprintf(stderr, "login: no shell: ");
-       perror(pwd->pw_shell);
+       (void)fprintf(stderr, "login: no shell: %s.\n", strerror(errno));

        exit(0);
 }
 
        exit(0);
 }
 


@@ -425,7 +483,7 @@ getloginname()
        static char nbuf[UT_NAMESIZE + 1];
 
        for (;;) {
        static char nbuf[UT_NAMESIZE + 1];
 
        for (;;) {

-               printf("login: ");
+               (void)printf("login: ");

                for (p = nbuf; (ch = getchar()) != '\n'; ) {
                        if (ch == EOF) {
                                badlogin(username);
                for (p = nbuf; (ch = getchar()) != '\n'; ) {
                        if (ch == EOF) {
                                badlogin(username);


@@ -436,7 +494,7 @@ getloginname()
                }
                if (p > nbuf)
                        if (nbuf[0] == '-')
                }
                if (p > nbuf)
                        if (nbuf[0] == '-')

-                               fprintf(stderr,
+                               (void)fprintf(stderr,

                                    "login names may not start with '-'.\n");
                        else {
                                *p = '\0';
                                    "login names may not start with '-'.\n");
                        else {
                                *p = '\0';


@@ -448,7 +506,7 @@ getloginname()
 
 timedout()
 {
 
 timedout()
 {

-       fprintf(stderr, "Login timed out after %d seconds\n", timeout);
+       (void)fprintf(stderr, "Login timed out after %d seconds\n", timeout);

        exit(0);
 }
 
        exit(0);
 }
 


@@ -508,13 +566,13 @@ dolastlog(quiet)
                if (!quiet) {
                        if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
                            ll.ll_time != 0) {
                if (!quiet) {
                        if (read(fd, (char *)&ll, sizeof(ll)) == sizeof(ll) &&
                            ll.ll_time != 0) {

-                               printf("Last login: %.*s ",
+                               (void)printf("Last login: %.*s ",

                                    24-5, (char *)ctime(&ll.ll_time));
                                if (*ll.ll_host != '\0')
                                    24-5, (char *)ctime(&ll.ll_time));
                                if (*ll.ll_host != '\0')

-                                       printf("from %.*s\n",
+                                       (void)printf("from %.*s\n",

                                            sizeof(ll.ll_host), ll.ll_host);
                                else
                                            sizeof(ll.ll_host), ll.ll_host);
                                else

-                                       printf("on %.*s\n",
+                                       (void)printf("on %.*s\n",

                                            sizeof(ll.ll_line), ll.ll_line);
                        }
                        (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);
                                            sizeof(ll.ll_line), ll.ll_line);
                        }
                        (void)lseek(fd, (off_t)pwd->pw_uid * sizeof(ll), L_SET);


@@ -564,7 +622,7 @@ getstr(buf, cnt, err)
                if (read(0, &ch, sizeof(ch)) != sizeof(ch))
                        exit(1);
                if (--cnt < 0) {
                if (read(0, &ch, sizeof(ch)) != sizeof(ch))
                        exit(1);
                if (--cnt < 0) {

-                       fprintf(stderr, "%s too long\r\n", err);
+                       (void)fprintf(stderr, "%s too long\r\n", err);

                        sleepexit(1);
                }
                *buf++ = ch;
                        sleepexit(1);
                }
                *buf++ = ch;


@@ -577,3 +635,46 @@ sleepexit(eval)
        sleep((u_int)5);
        exit(eval);
 }
        sleep((u_int)5);
        exit(eval);
 }

+
+doremotelogin(host)
+       char *host;
+{
+       static char lusername[UT_NAMESIZE+1];
+       char rusername[UT_NAMESIZE+1];
+
+       getstr(rusername, sizeof(rusername), "remuser");
+       getstr(lusername, sizeof(lusername), "locuser");
+       getstr(term, sizeof(term), "Terminal type");
+       username = lusername;
+       pwd = getpwnam(username);
+       if (pwd == NULL)
+               return(-1);
+       return(ruserok(host, (pwd->pw_uid == 0), rusername, username));
+}
+
+char *speeds[] = {
+       "0", "50", "75", "110", "134", "150", "200", "300", "600",
+       "1200", "1800", "2400", "4800", "9600", "19200", "38400",
+};
+#define        NSPEEDS (sizeof(speeds) / sizeof(speeds[0]))
+
+doremoteterm(tp)
+       struct sgttyb *tp;
+{
+       register char *cp = index(term, '/'), **cpp;
+       char *speed;
+
+       if (cp) {
+               *cp++ = '\0';
+               speed = cp;
+               cp = index(speed, '/');
+               if (cp)
+                       *cp++ = '\0';
+               for (cpp = speeds; cpp < &speeds[NSPEEDS]; cpp++)
+                       if (strcmp(*cpp, speed) == 0) {
+                               tp->sg_ispeed = tp->sg_ospeed = cpp-speeds;
+                               break;
+                       }
+       }
+       tp->sg_flags = ECHO|CRMOD|ANYP|XTABS;
+}