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 /*
37 * Try to find out what's a reasonable default principal.
38 */
39
40 static const char*
get_env_user(void)41 get_env_user(void)
42 {
43 const char *user = getenv("USER");
44 if(user == NULL)
45 user = getenv("LOGNAME");
46 if(user == NULL)
47 user = getenv("USERNAME");
48 return user;
49 }
50
51 #ifndef _WIN32
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
_krb5_get_default_principal_local(krb5_context context,krb5_principal * princ)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_message(context, ENOTTY,
89 N_("unable to figure out current "
90 "principal", ""));
91 return ENOTTY; /* XXX */
92 }
93 ret = krb5_make_principal(context, princ, NULL, user, NULL);
94 }
95 return ret;
96 }
97
98 #else /* _WIN32 */
99
100 #define SECURITY_WIN32
101 #include <security.h>
102
103 krb5_error_code
_krb5_get_default_principal_local(krb5_context context,krb5_principal * princ)104 _krb5_get_default_principal_local(krb5_context context,
105 krb5_principal *princ)
106 {
107 /* See if we can get the principal first. We only expect this to
108 work if logged into a domain. */
109 {
110 char username[1024];
111 ULONG sz = sizeof(username);
112
113 if (GetUserNameEx(NameUserPrincipal, username, &sz)) {
114 return krb5_parse_name_flags(context, username,
115 KRB5_PRINCIPAL_PARSE_ENTERPRISE,
116 princ);
117 }
118 }
119
120 /* Just get the Windows username. This should pretty much always
121 work. */
122 {
123 char username[1024];
124 DWORD dsz = sizeof(username);
125
126 if (GetUserName(username, &dsz)) {
127 return krb5_make_principal(context, princ, NULL, username, NULL);
128 }
129 }
130
131 /* Failing that, we look at the environment */
132 {
133 const char * username = get_env_user();
134
135 if (username == NULL) {
136 krb5_set_error_string(context,
137 "unable to figure out current principal");
138 return ENOTTY; /* Really? */
139 }
140
141 return krb5_make_principal(context, princ, NULL, username, NULL);
142 }
143 }
144
145 #endif
146
147 KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_default_principal(krb5_context context,krb5_principal * princ)148 krb5_get_default_principal (krb5_context context,
149 krb5_principal *princ)
150 {
151 krb5_error_code ret;
152 krb5_ccache id;
153
154 *princ = NULL;
155
156 ret = krb5_cc_default (context, &id);
157 if (ret == 0) {
158 ret = krb5_cc_get_principal (context, id, princ);
159 krb5_cc_close (context, id);
160 if (ret == 0)
161 return 0;
162 }
163
164 return _krb5_get_default_principal_local(context, princ);
165 }
166