1 /* 2 * Copyright (c) 1997 - 2001 Kungliga Tekniska H�gskolan 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 14870 2005-04-20 20:53:29Z lha $"); 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 /* 54 * Will only use operating-system dependant operation to get the 55 * default principal, for use of functions that in ccache layer to 56 * avoid recursive calls. 57 */ 58 59 krb5_error_code 60 _krb5_get_default_principal_local (krb5_context context, 61 krb5_principal *princ) 62 { 63 krb5_error_code ret; 64 const char *user; 65 uid_t uid; 66 67 *princ = NULL; 68 69 uid = getuid(); 70 if(uid == 0) { 71 user = getlogin(); 72 if(user == NULL) 73 user = get_env_user(); 74 if(user != NULL && strcmp(user, "root") != 0) 75 ret = krb5_make_principal(context, princ, NULL, user, "root", NULL); 76 else 77 ret = krb5_make_principal(context, princ, NULL, "root", NULL); 78 } else { 79 struct passwd *pw = getpwuid(uid); 80 if(pw != NULL) 81 user = pw->pw_name; 82 else { 83 user = get_env_user(); 84 if(user == NULL) 85 user = getlogin(); 86 } 87 if(user == NULL) { 88 krb5_set_error_string(context, 89 "unable to figure out current principal"); 90 return ENOTTY; /* XXX */ 91 } 92 ret = krb5_make_principal(context, princ, NULL, user, NULL); 93 } 94 return ret; 95 } 96 97 krb5_error_code KRB5_LIB_FUNCTION 98 krb5_get_default_principal (krb5_context context, 99 krb5_principal *princ) 100 { 101 krb5_error_code ret; 102 krb5_ccache id; 103 104 *princ = NULL; 105 106 ret = krb5_cc_default (context, &id); 107 if (ret == 0) { 108 ret = krb5_cc_get_principal (context, id, princ); 109 krb5_cc_close (context, id); 110 if (ret == 0) 111 return 0; 112 } 113 114 return _krb5_get_default_principal_local(context, princ); 115 } 116