1 /* $NetBSD: get_default_principal.c,v 1.4 2023/06/19 21:41:44 christos 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_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_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, *pwd = NULL;
82 char pwbuf[2048];
83
84 if (rk_getpwuid_r(uid, &pw, pwbuf, sizeof(pwbuf), &pwd) == 0)
85 user = pwd->pw_name;
86 else {
87 user = get_env_user();
88 if(user == NULL)
89 user = getlogin();
90 }
91 if(user == NULL) {
92 krb5_set_error_message(context, ENOTTY,
93 N_("unable to figure out current "
94 "principal", ""));
95 return ENOTTY; /* XXX */
96 }
97 ret = krb5_make_principal(context, princ, NULL, user, NULL);
98 }
99 return ret;
100 }
101
102 #else /* _WIN32 */
103
104 #define SECURITY_WIN32
105 #include <security.h>
106
107 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
_krb5_get_default_principal_local(krb5_context context,krb5_principal * princ)108 _krb5_get_default_principal_local(krb5_context context,
109 krb5_principal *princ)
110 {
111 /* See if we can get the principal first. We only expect this to
112 work if logged into a domain. */
113 {
114 char username[1024];
115 ULONG sz = sizeof(username);
116
117 if (GetUserNameEx(NameUserPrincipal, username, &sz)) {
118 return krb5_parse_name_flags(context, username,
119 KRB5_PRINCIPAL_PARSE_ENTERPRISE,
120 princ);
121 }
122 }
123
124 /* Just get the Windows username. This should pretty much always
125 work. */
126 {
127 char username[1024];
128 DWORD dsz = sizeof(username);
129
130 if (GetUserName(username, &dsz)) {
131 return krb5_make_principal(context, princ, NULL, username, NULL);
132 }
133 }
134
135 /* Failing that, we look at the environment */
136 {
137 const char * username = get_env_user();
138
139 if (username == NULL) {
140 krb5_set_error_string(context,
141 "unable to figure out current principal");
142 return ENOTTY; /* Really? */
143 }
144
145 return krb5_make_principal(context, princ, NULL, username, NULL);
146 }
147 }
148
149 #endif
150
151 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_default_principal(krb5_context context,krb5_principal * princ)152 krb5_get_default_principal (krb5_context context,
153 krb5_principal *princ)
154 {
155 krb5_error_code ret;
156 krb5_ccache id;
157
158 *princ = NULL;
159
160 ret = krb5_cc_default (context, &id);
161 if (ret == 0) {
162 ret = krb5_cc_get_principal (context, id, princ);
163 krb5_cc_close (context, id);
164 if (ret == 0)
165 return 0;
166 }
167
168 return _krb5_get_default_principal_local(context, princ);
169 }
170