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
40static const char*
41get_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
59krb5_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_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
103krb5_error_code
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
147KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
148krb5_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