crypto/heimdal-0.6.3/lib/krb5/get_default_principal.c

   1 /*
   2  * Copyright (c) 1997 - 2001 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: get_default_principal.c,v 1.7 2001/05/14 06:14:46 assar Exp $");
  37
  38 /*
  39  * Try to find out what's a reasonable default principal.
  40  */
  41
  42 static const char*
  43 get_env_user(void)
  44 {
  45     const char *user = getenv("USER");
  46     if(user == NULL)
  47         user = getenv("LOGNAME");
  48     if(user == NULL)
  49         user = getenv("USERNAME");
  50     return user;
  51 }
  52
  53 krb5_error_code
  54 krb5_get_default_principal (krb5_context context,
  55                             krb5_principal *princ)
  56 {
  57     krb5_error_code ret;
  58     krb5_ccache id;
  59     const char *user;
  60     uid_t uid;
  61
  62     ret = krb5_cc_default (context, &id);
  63     if (ret == 0) {
  64         ret = krb5_cc_get_principal (context, id, princ);
  65         krb5_cc_close (context, id);
  66         if (ret == 0)
  67             return 0;
  68     }
  69
  70
  71     uid = getuid();
  72     if(uid == 0) {
  73         user = getlogin();
  74         if(user == NULL)
  75             user = get_env_user();
  76         if(user != NULL && strcmp(user, "root") != 0)
  77             ret = krb5_make_principal(context, princ, NULL, user, "root", NULL);
  78         else
  79             ret = krb5_make_principal(context, princ, NULL, "root", NULL);
  80     } else {
  81         struct passwd *pw = getpwuid(uid);
  82         if(pw != NULL)
  83             user = pw->pw_name;
  84         else {
  85             user = get_env_user();
  86             if(user == NULL)
  87                 user = getlogin();
  88         }
  89         if(user == NULL) {
  90             krb5_set_error_string(context,
  91                                   "unable to figure out current principal");
  92             return ENOTTY; /* XXX */
  93         }
  94         ret = krb5_make_principal(context, princ, NULL, user, NULL);
  95     }
  96
  97     return ret;
  98 }