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