xref: /minix3/crypto/external/bsd/heimdal/dist/lib/krb5/get_default_principal.c (revision 0a6a1f1d05b60e214de2f05a7310ddd1f0e590e7)
1 /*	$NetBSD: get_default_principal.c,v 1.1.1.2 2014/04/24 12:45:50 pettai Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "krb5_locl.h"
37 
38 /*
39  * Try to find out what's a reasonable default principal.
40  */
41 
42 static const char*
get_env_user(void)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 #ifndef _WIN32
54 
55 /*
56  * Will only use operating-system dependant operation to get the
57  * default principal, for use of functions that in ccache layer to
58  * avoid recursive calls.
59  */
60 
61 krb5_error_code
_krb5_get_default_principal_local(krb5_context context,krb5_principal * princ)62 _krb5_get_default_principal_local (krb5_context context,
63 				   krb5_principal *princ)
64 {
65     krb5_error_code ret;
66     const char *user;
67     uid_t uid;
68 
69     *princ = NULL;
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_message(context, ENOTTY,
91 				   N_("unable to figure out current "
92 				      "principal", ""));
93 	    return ENOTTY; /* XXX */
94 	}
95 	ret = krb5_make_principal(context, princ, NULL, user, NULL);
96     }
97     return ret;
98 }
99 
100 #else  /* _WIN32 */
101 
102 #define SECURITY_WIN32
103 #include <security.h>
104 
105 krb5_error_code
_krb5_get_default_principal_local(krb5_context context,krb5_principal * princ)106 _krb5_get_default_principal_local(krb5_context context,
107 				  krb5_principal *princ)
108 {
109     /* See if we can get the principal first.  We only expect this to
110        work if logged into a domain. */
111     {
112 	char username[1024];
113 	ULONG sz = sizeof(username);
114 
115 	if (GetUserNameEx(NameUserPrincipal, username, &sz)) {
116 	    return krb5_parse_name_flags(context, username,
117 					 KRB5_PRINCIPAL_PARSE_ENTERPRISE,
118 					 princ);
119 	}
120     }
121 
122     /* Just get the Windows username.  This should pretty much always
123        work. */
124     {
125 	char username[1024];
126 	DWORD dsz = sizeof(username);
127 
128 	if (GetUserName(username, &dsz)) {
129 	    return krb5_make_principal(context, princ, NULL, username, NULL);
130 	}
131     }
132 
133     /* Failing that, we look at the environment */
134     {
135 	const char * username = get_env_user();
136 
137 	if (username == NULL) {
138 	    krb5_set_error_string(context,
139 				  "unable to figure out current principal");
140 	    return ENOTTY;	/* Really? */
141 	}
142 
143 	return krb5_make_principal(context, princ, NULL, username, NULL);
144     }
145 }
146 
147 #endif
148 
149 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_default_principal(krb5_context context,krb5_principal * princ)150 krb5_get_default_principal (krb5_context context,
151 			    krb5_principal *princ)
152 {
153     krb5_error_code ret;
154     krb5_ccache id;
155 
156     *princ = NULL;
157 
158     ret = krb5_cc_default (context, &id);
159     if (ret == 0) {
160 	ret = krb5_cc_get_principal (context, id, princ);
161 	krb5_cc_close (context, id);
162 	if (ret == 0)
163 	    return 0;
164     }
165 
166     return _krb5_get_default_principal_local(context, princ);
167 }
168