summaryrefslogtreecommitdiff
path: root/source4/heimdal/lib/krb5/get_default_principal.c
blob: 44baa6d1c2cdfb51ca855a2f9392b692cae54489 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
 * Copyright (c) 1997 - 2001 Kungliga Tekniska Högskolan
 * (Royal Institute of Technology, Stockholm, Sweden).
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * 3. Neither the name of the Institute nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#include "krb5_locl.h"

/*
 * Try to find out what's a reasonable default principal.
 */

static const char*
get_env_user(void)
{
    const char *user = getenv("USER");
    if(user == NULL)
	user = getenv("LOGNAME");
    if(user == NULL)
	user = getenv("USERNAME");
    return user;
}

#ifndef _WIN32

/*
 * Will only use operating-system dependant operation to get the
 * default principal, for use of functions that in ccache layer to
 * avoid recursive calls.
 */

krb5_error_code
_krb5_get_default_principal_local (krb5_context context,
				   krb5_principal *princ)
{
    krb5_error_code ret;
    const char *user;
    uid_t uid;

    *princ = NULL;

    uid = getuid();
    if(uid == 0) {
	user = getlogin();
	if(user == NULL)
	    user = get_env_user();
	if(user != NULL && strcmp(user, "root") != 0)
	    ret = krb5_make_principal(context, princ, NULL, user, "root", NULL);
	else
	    ret = krb5_make_principal(context, princ, NULL, "root", NULL);
    } else {
	struct passwd *pw = getpwuid(uid);
	if(pw != NULL)
	    user = pw->pw_name;
	else {
	    user = get_env_user();
	    if(user == NULL)
		user = getlogin();
	}
	if(user == NULL) {
	    krb5_set_error_message(context, ENOTTY,
				   N_("unable to figure out current "
				      "principal", ""));
	    return ENOTTY; /* XXX */
	}
	ret = krb5_make_principal(context, princ, NULL, user, NULL);
    }
    return ret;
}

#else  /* _WIN32 */

#define SECURITY_WIN32
#include <security.h>

krb5_error_code
_krb5_get_default_principal_local(krb5_context context,
				  krb5_principal *princ)
{
    /* See if we can get the principal first.  We only expect this to
       work if logged into a domain. */
    {
	char username[1024];
	ULONG sz = sizeof(username);

	if (GetUserNameEx(NameUserPrincipal, username, &sz)) {
	    return krb5_parse_name_flags(context, username,
					 KRB5_PRINCIPAL_PARSE_ENTERPRISE,
					 princ);
	}
    }

    /* Just get the Windows username.  This should pretty much always
       work. */
    {
	char username[1024];
	DWORD dsz = sizeof(username);

	if (GetUserName(username, &dsz)) {
	    return krb5_make_principal(context, princ, NULL, username, NULL);
	}
    }

    /* Failing that, we look at the environment */
    {
	const char * username = get_env_user();

	if (username == NULL) {
	    krb5_set_error_string(context,
				  "unable to figure out current principal");
	    return ENOTTY;	/* Really? */
	}

	return krb5_make_principal(context, princ, NULL, username, NULL);
    }
}

#endif

KRB5_LIB_FUNCTION krb5_error_code KRB5_LIB_CALL
krb5_get_default_principal (krb5_context context,
			    krb5_principal *princ)
{
    krb5_error_code ret;
    krb5_ccache id;

    *princ = NULL;

    ret = krb5_cc_default (context, &id);
    if (ret == 0) {
	ret = krb5_cc_get_principal (context, id, princ);
	krb5_cc_close (context, id);
	if (ret == 0)
	    return 0;
    }

    return _krb5_get_default_principal_local(context, princ);
}