lib/krb5/kuserok.c

   1 /*
   2  * Copyright (c) 1997 - 1999 Kungliga Tekniska Högskolan
   3  * (Royal Institute of Technology, Stockholm, Sweden).
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the Institute nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
  22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
  25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  31  * SUCH DAMAGE.
  32  */
  33
  34 #include "krb5_locl.h"
  35
  36 RCSID("$Id$");
  37
  38 /*
  39  * Return TRUE iff `principal' is allowed to login as `luser'.
  40  */
  41
  42 krb5_boolean
  43 krb5_kuserok (krb5_context context,
  44               krb5_principal principal,
  45               const char *luser)
  46 {
  47     char buf[BUFSIZ];
  48     struct passwd *pwd;
  49     FILE *f;
  50     krb5_realm *realms, *r;
  51     krb5_error_code ret;
  52     krb5_boolean b;
  53
  54     ret = krb5_get_default_realms (context, &realms);
  55     if (ret)
  56         return FALSE;
  57
  58     for (r = realms; *r != NULL; ++r) {
  59         krb5_principal local_principal;
  60
  61         ret = krb5_build_principal (context,
  62                                     &local_principal,
  63                                     strlen(*r),
  64                                     *r,
  65                                     luser,
  66                                     NULL);
  67         if (ret) {
  68             krb5_free_host_realm (context, realms);
  69             return FALSE;
  70         }
  71
  72         b = krb5_principal_compare (context, principal, local_principal);
  73         krb5_free_principal (context, local_principal);
  74         if (b) {
  75             krb5_free_host_realm (context, realms);
  76             return TRUE;
  77         }
  78     }
  79     krb5_free_host_realm (context, realms);
  80
  81     pwd = getpwnam (luser);     /* XXX - Should use k_getpwnam? */
  82     if (pwd == NULL)
  83         return FALSE;
  84     snprintf (buf, sizeof(buf), "%s/.k5login", pwd->pw_dir);
  85     f = fopen (buf, "r");
  86     if (f == NULL)
  87         return FALSE;
  88     while (fgets (buf, sizeof(buf), f) != NULL) {
  89         krb5_principal tmp;
  90
  91         buf[strcspn(buf, "\n")] = '\0';
  92         ret = krb5_parse_name (context, buf, &tmp);
  93         if (ret) {
  94             fclose (f);
  95             return FALSE;
  96         }
  97         b = krb5_principal_compare (context, principal, tmp);
  98         krb5_free_principal (context, tmp);
  99         if (b) {
 100             fclose (f);
 101             return TRUE;
 102         }
 103     }
 104     fclose (f);
 105     return FALSE;
 106 }