diff options
Diffstat (limited to 'crypto/kerberosIV/appl/bsd/su.c')
| -rw-r--r-- | crypto/kerberosIV/appl/bsd/su.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/crypto/kerberosIV/appl/bsd/su.c b/crypto/kerberosIV/appl/bsd/su.c new file mode 100644 index 0000000..8c610e1 --- /dev/null +++ b/crypto/kerberosIV/appl/bsd/su.c @@ -0,0 +1,452 @@ +/* + * 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. + */ + +#include "bsd_locl.h" + +RCSID ("$Id: su.c,v 1.59 1997/05/26 17:45:54 bg Exp $"); + +#ifdef SYSV_SHADOW +#include "sysv_shadow.h" +#endif + +static int kerberos (char *username, char *user, int uid); +static int chshell (char *sh); +static char *ontty (void); +static int koktologin (char *name, char *realm, char *toname); +static int chshell (char *sh); + +/* Handle '-' option after all the getopt options */ +#define ARGSTR "Kflmi:" + +static int use_kerberos = 1; +static char *root_inst = "root"; + +int +main (int argc, char **argv) +{ + struct passwd *pwd; + char *p, **g; + struct group *gr; + uid_t ruid; + int asme, ch, asthem, fastlogin, prio; + enum { UNSET, YES, NO } iscsh = UNSET; + char *user, *shell, *avshell, *username, **np; + char shellbuf[MaxPathLen], avshellbuf[MaxPathLen]; + + set_progname (argv[0]); + + asme = asthem = fastlogin = 0; + while ((ch = getopt (argc, argv, ARGSTR)) != EOF) + switch ((char) ch) { + case 'K': + use_kerberos = 0; + break; + case 'f': + fastlogin = 1; + break; + case 'l': + asme = 0; + asthem = 1; + break; + case 'm': + asme = 1; + asthem = 0; + break; + case 'i': + root_inst = optarg; + break; + case '?': + default: + fprintf (stderr, + "usage: su [-Kflm] [-i root-instance] [-] [login]\n"); + exit (1); + } + /* Don't handle '-' option with getopt */ + if (optind < argc && strcmp (argv[optind], "-") == 0) { + asme = 0; + asthem = 1; + optind++; + } + argv += optind; + + if (use_kerberos) { + int fd = open (KEYFILE, O_RDONLY); + + if (fd >= 0) + close (fd); + else + use_kerberos = 0; + } + errno = 0; + prio = getpriority (PRIO_PROCESS, 0); + if (errno) + prio = 0; + setpriority (PRIO_PROCESS, 0, -2); + openlog ("su", LOG_CONS, 0); + + /* get current login name and shell */ + ruid = getuid (); + username = getlogin (); + if (username == NULL || (pwd = k_getpwnam (username)) == NULL || + pwd->pw_uid != ruid) + pwd = k_getpwuid (ruid); + if (pwd == NULL) + errx (1, "who are you?"); + 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"; + np = *argv ? argv : argv - 1; + + pwd = k_getpwnam (user); + if (pwd == NULL) + errx (1, "unknown login %s", user); + if (pwd->pw_uid == 0 && strcmp ("root", user) != 0) { + syslog (LOG_ALERT, "NIS attack, user %s has uid 0", user); + errx (1, "unknown login %s", user); + } + if (!use_kerberos || kerberos (username, user, pwd->pw_uid)) { +#ifndef PASSWD_FALLBACK + errx (1, "won't use /etc/passwd authentication"); +#endif + /* getpwnam() is not reentrant and kerberos might use it! */ + pwd = k_getpwnam (user); + if (pwd == NULL) + errx (1, "unknown login %s", user); + /* 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) { +#if 1 + /* if group 0 is empty or only + contains root su is still ok. */ + if (gr->gr_mem[0] == 0) + break; /* group 0 is empty */ + if (gr->gr_mem[1] == 0 && + strcmp (gr->gr_mem[0], "root") == 0) + break; /* only root in group 0 */ +#endif + errx (1, "you are not in the correct group to su %s.", + user); + } + if (!strcmp (username, *g)) + break; + } + /* if target requires a password, verify it */ + if (ruid && *pwd->pw_passwd) { + char prompt[128]; + char passwd[256]; + + snprintf (prompt, sizeof(prompt), "%s's Password: ", pwd->pw_name); + if (des_read_pw_string (passwd, sizeof (passwd), + prompt, 0)) { + memset (passwd, 0, sizeof (passwd)); + exit (1); + } + if (strcmp (pwd->pw_passwd, + crypt (passwd, pwd->pw_passwd))) { + memset (passwd, 0, sizeof (passwd)); + syslog (LOG_AUTH | LOG_WARNING, + "BAD SU %s to %s%s", username, + user, ontty ()); + errx (1, "Sorry"); + } + memset (passwd, 0, sizeof (passwd)); + } + } + if (asme) { + /* if asme and non-standard target shell, must be root */ + if (!chshell (pwd->pw_shell) && ruid) + errx (1, "permission denied (shell '%s' not in /etc/shells).", + pwd->pw_shell); + } else if (pwd->pw_shell && *pwd->pw_shell) { + shell = pwd->pw_shell; + iscsh = UNSET; + } else { + shell = _PATH_BSHELL; + iscsh = NO; + } + + if ((p = strrchr (shell, '/')) != 0) + avshell = p + 1; + else + avshell = shell; + + /* if we're forking a csh, we want to slightly muck the args */ + if (iscsh == UNSET) + iscsh = strcmp (avshell, "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) { + char *k = getenv ("KRBTKFILE"); + char *t = getenv ("TERM"); + + environ = malloc (10 * sizeof (char *)); + environ[0] = NULL; + setenv ("PATH", _PATH_DEFPATH, 1); + if (t) + setenv ("TERM", t, 1); + if (k) + setenv ("KRBTKFILE", k, 1); + if (chdir (pwd->pw_dir) < 0) + errx (1, "no directory"); + } + if (asthem || pwd->pw_uid) + setenv ("USER", pwd->pw_name, 1); + setenv ("HOME", pwd->pw_dir, 1); + setenv ("SHELL", shell, 1); + } + if (iscsh == YES) { + if (fastlogin) + *np-- = "-f"; + if (asme) + *np-- = "-m"; + } + if (asthem) { + avshellbuf[0] = '-'; + strcpy (avshellbuf + 1, avshell); + avshell = avshellbuf; + } else if (iscsh == YES) { + /* csh strips the first character... */ + avshellbuf[0] = '_'; + strcpy (avshellbuf + 1, avshell); + avshell = avshellbuf; + } + *np = avshell; + + if (ruid != 0) + syslog (LOG_NOTICE | LOG_AUTH, "%s to %s%s", + username, user, ontty ()); + + setpriority (PRIO_PROCESS, 0, prio); + + if (k_hasafs ()) { + int code; + + if (k_setpag () != 0) + warn ("setpag"); + code = k_afsklog (0, 0); + if (code != KSUCCESS && code != KDC_PR_UNKNOWN) + warnx ("afsklog: %s", krb_get_err_text (code)); + } + execv (shell, np); + warn ("execv(%s)", shell); + if (getuid () == 0) { + execv (_PATH_BSHELL, np); + warn ("execv(%s)", _PATH_BSHELL); + } + exit (1); +} + +static int +chshell (char *sh) +{ + char *cp; + + while ((cp = getusershell ()) != NULL) + if (!strcmp (cp, sh)) + return (1); + return (0); +} + +static char * +ontty (void) +{ + char *p; + static char buf[MaxPathLen + 4]; + + buf[0] = 0; + if ((p = ttyname (STDERR_FILENO)) != 0) + snprintf (buf, sizeof(buf), " on %s", p); + return (buf); +} + +static int +kerberos (char *username, char *user, int uid) +{ + KTEXT_ST ticket; + AUTH_DAT authdata; + struct hostent *hp; + int kerno; + u_long faddr; + char lrealm[REALM_SZ], krbtkfile[MaxPathLen]; + char hostname[MaxHostNameLen], savehost[MaxHostNameLen]; + + if (krb_get_lrealm (lrealm, 1) != KSUCCESS) + return (1); + if (koktologin (username, lrealm, user) && !uid) { +#ifndef PASSWD_FALLBACK + warnx ("not in %s's ACL.", user); +#endif + return (1); + } + snprintf (krbtkfile, sizeof(krbtkfile), + "%s_%s_to_%s_%u", TKT_ROOT, username, user, + (unsigned) getpid ()); + + setenv ("KRBTKFILE", krbtkfile, 1); + krb_set_tkt_string (krbtkfile); + /* + * 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. + */ + { + char prompt[128]; + char passw[256]; + + snprintf (prompt, sizeof(prompt), + "%s's Password: ", + krb_unparse_name_long ((uid == 0 ? username : user), + (uid == 0 ? root_inst : ""), + lrealm)); + if (des_read_pw_string (passw, sizeof (passw), prompt, 0)) { + memset (passw, 0, sizeof (passw)); + return (1); + } + if (strlen(passw) == 0) + return (1); /* Empty passwords is not allowed */ + kerno = krb_get_pw_in_tkt ((uid == 0 ? username : user), + (uid == 0 ? root_inst : ""), lrealm, + KRB_TICKET_GRANTING_TICKET, + lrealm, + DEFAULT_TKT_LIFE, + passw); + memset (passw, 0, strlen (passw)); + } + + if (kerno != KSUCCESS) { + if (kerno == KDC_PR_UNKNOWN) { + warnx ("principal unknown: %s", + krb_unparse_name_long ((uid == 0 ? username : user), + (uid == 0 ? root_inst : ""), + lrealm)); + return (1); + } + warnx ("unable to su: %s", krb_get_err_text (kerno)); + syslog (LOG_NOTICE | LOG_AUTH, + "BAD SU: %s to %s%s: %s", + username, user, ontty (), krb_get_err_text (kerno)); + return (1); + } + if (chown (krbtkfile, uid, -1) < 0) { + warn ("chown"); + unlink (krbtkfile); + return (1); + } + setpriority (PRIO_PROCESS, 0, -2); + + if (k_gethostname (hostname, sizeof (hostname)) == -1) { + warn ("gethostname"); + dest_tkt (); + return (1); + } + 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_get_err_text (kerno), + "rcmd", savehost); +#ifdef KLOGIN_PARANOID + /* + * if the "VERIFY_SERVICE" doesn't exist in the KDC for this host, * + * don't allow kerberos login, also log the error condition. + */ + warnx ("Trying local password!"); + return (1); +#endif + } else if (kerno != KSUCCESS) { + warnx ("Unable to use TGT: %s", krb_get_err_text (kerno)); + syslog (LOG_NOTICE | LOG_AUTH, "failed su: %s to %s%s: %s", + username, user, ontty (), krb_get_err_text (kerno)); + dest_tkt (); + return (1); + } else { + if (!(hp = gethostbyname (hostname))) { + warnx ("can't get addr of %s", hostname); + dest_tkt (); + return (1); + } + memcpy (&faddr, hp->h_addr, sizeof (faddr)); + + if ((kerno = krb_rd_req (&ticket, "rcmd", savehost, faddr, + &authdata, "")) != KSUCCESS) { + warnx ("unable to verify rcmd ticket: %s", + krb_get_err_text (kerno)); + syslog (LOG_NOTICE | LOG_AUTH, + "failed su: %s to %s%s: %s", username, + user, ontty (), krb_get_err_text (kerno)); + dest_tkt (); + return (1); + } + } + fprintf (stderr, "Don't forget to kdestroy before exiting the shell.\n"); + return (0); +} + +static int +koktologin (char *name, char *realm, char *toname) +{ + return krb_kuserok (name, + strcmp (toname, "root") == 0 ? root_inst : "", + realm, + toname); +} |
