read_servi.c revision 781:57319a72b15f 
1/*
2 * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
3 * Use is subject to license terms.
4 */
5
6#pragma ident	"%Z%%M%	%I%	%E% SMI"
7
8/*
9 * lib/krb5/keytab/read_servi.c
10 *
11 * Copyright 1990 by the Massachusetts Institute of Technology.
12 * All Rights Reserved.
13 *
14 * Export of this software from the United States of America may
15 *   require a specific license from the United States Government.
16 *   It is the responsibility of any person or organization contemplating
17 *   export to obtain such a license before exporting.
18 *
19 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
20 * distribute this software and its documentation for any purpose and
21 * without fee is hereby granted, provided that the above copyright
22 * notice appear in all copies and that both that copyright notice and
23 * this permission notice appear in supporting documentation, and that
24 * the name of M.I.T. not be used in advertising or publicity pertaining
25 * to distribution of the software without specific, written prior
26 * permission.  Furthermore if you modify this software you must label
27 * your software as modified software and not distribute it in such a
28 * fashion that it might be confused with the original M.I.T. software.
29 * M.I.T. makes no representations about the suitability of
30 * this software for any purpose.  It is provided "as is" without express
31 * or implied warranty.
32 *
33 *
34 * This routine is designed to be passed to krb5_rd_req.
35 * It is a convenience function that reads a key out of a keytab.
36 * It handles all of the opening and closing of the keytab
37 * internally.
38 */
39
40#include <k5-int.h>
41
42#define KSUCCESS 0
43
44/*
45 * effects: If keyprocarg is not NULL, it is taken to be the name of a
46 *	keytab.  Otherwise, the default keytab will be used.  This
47 *	routine opens the keytab and finds the principal associated with
48 *	principal, vno, and enctype and returns the resulting key in *key
49 *	or returning an error code if it is not	found.
50 * returns: Either KSUCCESS or error code.
51 * errors: error code if not found or keyprocarg is invalid.
52 */
53krb5_error_code KRB5_CALLCONV
54krb5_kt_read_service_key(krb5_context context, krb5_pointer keyprocarg, krb5_principal principal, krb5_kvno vno, krb5_enctype enctype, krb5_keyblock **key)
55{
56    krb5_error_code kerror = KSUCCESS;
57    char keytabname[MAX_KEYTAB_NAME_LEN + 1]; /* + 1 for NULL termination */
58    krb5_keytab id;
59    krb5_keytab_entry entry;
60
61    /*
62     * Get the name of the file that we should use.
63     */
64    if (!keyprocarg) {
65	if ((kerror = krb5_kt_default_name(context, (char *)keytabname,
66					   sizeof(keytabname) - 1))!= KSUCCESS)
67	    return (kerror);
68    } else {
69	memset(keytabname, 0, sizeof(keytabname));
70	(void) strncpy(keytabname, (char *)keyprocarg,
71		       sizeof(keytabname) - 1);
72    }
73
74    if ((kerror = krb5_kt_resolve(context, (char *)keytabname, &id)))
75	return (kerror);
76
77    kerror = krb5_kt_get_entry(context, id, principal, vno, enctype, &entry);
78    (void) krb5_kt_close(context, id);
79
80    if (kerror)
81	return(kerror);
82
83    krb5_copy_keyblock(context, &entry.key, key);
84
85    krb5_kt_free_entry(context, &entry);
86
87    return (KSUCCESS);
88}
89