xref: /freebsd/kerberos5/lib/libgssapi_krb5/pname_to_uid.c (revision 5ca8e32633c4ffbbcd6762e5888b6a4ba0708c6c)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause
3  *
4  * Copyright (c) 2008 Isilon Inc http://www.isilon.com/
5  * Authors: Doug Rabson <dfr@rabson.org>
6  * Developed with Red Inc: Alfred Perlstein <alfred@freebsd.org>
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  * 1. Redistributions of source code must retain the above copyright
12  *    notice, this list of conditions and the following disclaimer.
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  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include <errno.h>
31 #include <pwd.h>
32 
33 #include "krb5/gsskrb5_locl.h"
34 
35 OM_uint32
36 _gsskrb5_pname_to_uid(OM_uint32 *minor_status, const gss_name_t pname,
37     const gss_OID mech, uid_t *uidp)
38 {
39 	krb5_context context;
40 	krb5_const_principal name = (krb5_const_principal) pname;
41 	krb5_error_code kret;
42 	char lname[MAXLOGNAME + 1], buf[1024], *bufp;
43 	struct passwd pwd, *pw;
44 	size_t buflen;
45 	int error;
46 	OM_uint32 ret;
47 	static size_t buflen_hint = 1024;
48 
49 	GSSAPI_KRB5_INIT (&context);
50 
51 	kret = krb5_aname_to_localname(context, name, sizeof(lname), lname);
52 	if (kret) {
53 		*minor_status = kret;
54 		return (GSS_S_FAILURE);
55 	}
56 
57 	*minor_status = 0;
58 	buflen = buflen_hint;
59 	for (;;) {
60 		pw = NULL;
61 		bufp = buf;
62 		if (buflen > sizeof(buf))
63 			bufp = malloc(buflen);
64 		if (bufp == NULL)
65 			break;
66 		error = getpwnam_r(lname, &pwd, bufp, buflen, &pw);
67 		if (error != ERANGE)
68 			break;
69 		if (buflen > sizeof(buf))
70 			free(bufp);
71 		buflen += 1024;
72 		if (buflen > buflen_hint)
73 			buflen_hint = buflen;
74 	}
75 	if (pw) {
76 		*uidp = pw->pw_uid;
77 		ret = GSS_S_COMPLETE;
78 	} else {
79 		ret = GSS_S_FAILURE;
80 	}
81 	if (bufp != NULL && buflen > sizeof(buf))
82 		free(bufp);
83 	return (ret);
84 }
85