xref: /freebsd/kerberos5/lib/libgssapi_krb5/pname_to_uid.c (revision af23369a6deaaeb612ab266eb88b8bb8d560c322)
1 /*-
2  * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
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 /* $FreeBSD$ */
30 
31 #include <errno.h>
32 #include <pwd.h>
33 
34 #include "krb5/gsskrb5_locl.h"
35 
36 OM_uint32
37 _gsskrb5_pname_to_uid(OM_uint32 *minor_status, const gss_name_t pname,
38     const gss_OID mech, uid_t *uidp)
39 {
40 	krb5_context context;
41 	krb5_const_principal name = (krb5_const_principal) pname;
42 	krb5_error_code kret;
43 	char lname[MAXLOGNAME + 1], buf[1024], *bufp;
44 	struct passwd pwd, *pw;
45 	size_t buflen;
46 	int error;
47 	OM_uint32 ret;
48 	static size_t buflen_hint = 1024;
49 
50 	GSSAPI_KRB5_INIT (&context);
51 
52 	kret = krb5_aname_to_localname(context, name, sizeof(lname), lname);
53 	if (kret) {
54 		*minor_status = kret;
55 		return (GSS_S_FAILURE);
56 	}
57 
58 	*minor_status = 0;
59 	buflen = buflen_hint;
60 	for (;;) {
61 		pw = NULL;
62 		bufp = buf;
63 		if (buflen > sizeof(buf))
64 			bufp = malloc(buflen);
65 		if (bufp == NULL)
66 			break;
67 		error = getpwnam_r(lname, &pwd, bufp, buflen, &pw);
68 		if (error != ERANGE)
69 			break;
70 		if (buflen > sizeof(buf))
71 			free(bufp);
72 		buflen += 1024;
73 		if (buflen > buflen_hint)
74 			buflen_hint = buflen;
75 	}
76 	if (pw) {
77 		*uidp = pw->pw_uid;
78 		ret = GSS_S_COMPLETE;
79 	} else {
80 		ret = GSS_S_FAILURE;
81 	}
82 	if (bufp != NULL && buflen > sizeof(buf))
83 		free(bufp);
84 	return (ret);
85 }
86