1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /*
3 * Copyright (C) 2009 by the Massachusetts Institute of Technology.
4 * All rights reserved.
5 *
6 * Export of this software from the United States of America may
7 * require a specific license from the United States Government.
8 * It is the responsibility of any person or organization contemplating
9 * export to obtain such a license before exporting.
10 *
11 * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
12 * distribute this software and its documentation for any purpose and
13 * without fee is hereby granted, provided that the above copyright
14 * notice appear in all copies and that both that copyright notice and
15 * this permission notice appear in supporting documentation, and that
16 * the name of M.I.T. not be used in advertising or publicity pertaining
17 * to distribution of the software without specific, written prior
18 * permission. Furthermore if you modify this software you must label
19 * your software as modified software and not distribute it in such a
20 * fashion that it might be confused with the original M.I.T. software.
21 * M.I.T. makes no representations about the suitability of
22 * this software for any purpose. It is provided "as is" without express
23 * or implied warranty.
24 *
25 * Functions for manipulating krb5_key structures
26 */
27
28 #include "crypto_int.h"
29
30 /*
31 * The krb5_key data type wraps an exposed keyblock in an opaque data
32 * structure, to allow for internal optimizations such as caching of
33 * derived keys.
34 */
35
36 /* Create a krb5_key from the enctype and key data in a keyblock. */
37 krb5_error_code KRB5_CALLCONV
krb5_k_create_key(krb5_context context,const krb5_keyblock * key_data,krb5_key * out)38 krb5_k_create_key(krb5_context context, const krb5_keyblock *key_data,
39 krb5_key *out)
40 {
41 krb5_key key = NULL;
42 krb5_error_code code;
43
44 *out = NULL;
45
46 key = malloc(sizeof(*key));
47 if (key == NULL)
48 return ENOMEM;
49 code = krb5int_c_copy_keyblock_contents(context, key_data, &key->keyblock);
50 if (code)
51 goto cleanup;
52
53 key->refcount = 1;
54 key->derived = NULL;
55 key->cache = NULL;
56 *out = key;
57 return 0;
58
59 cleanup:
60 free(key);
61 return code;
62 }
63
64 void KRB5_CALLCONV
krb5_k_reference_key(krb5_context context,krb5_key key)65 krb5_k_reference_key(krb5_context context, krb5_key key)
66 {
67 if (key)
68 key->refcount++;
69 }
70
71 /* Free the memory used by a krb5_key. */
72 void KRB5_CALLCONV
krb5_k_free_key(krb5_context context,krb5_key key)73 krb5_k_free_key(krb5_context context, krb5_key key)
74 {
75 struct derived_key *dk;
76 const struct krb5_keytypes *ktp;
77
78 if (key == NULL || --key->refcount > 0)
79 return;
80
81 /* Free the derived key cache. */
82 while ((dk = key->derived) != NULL) {
83 key->derived = dk->next;
84 free(dk->constant.data);
85 krb5_k_free_key(context, dk->dkey);
86 free(dk);
87 }
88 krb5int_c_free_keyblock_contents(context, &key->keyblock);
89 if (key->cache) {
90 ktp = find_enctype(key->keyblock.enctype);
91 if (ktp && ktp->enc->key_cleanup)
92 ktp->enc->key_cleanup(key);
93 }
94 free(key);
95 }
96
97 /* Retrieve a copy of the keyblock from a krb5_key. */
98 krb5_error_code KRB5_CALLCONV
krb5_k_key_keyblock(krb5_context context,krb5_key key,krb5_keyblock ** key_data)99 krb5_k_key_keyblock(krb5_context context, krb5_key key,
100 krb5_keyblock **key_data)
101 {
102 return krb5int_c_copy_keyblock(context, &key->keyblock, key_data);
103 }
104
105 /* Retrieve the enctype of a krb5_key. */
106 krb5_enctype KRB5_CALLCONV
krb5_k_key_enctype(krb5_context context,krb5_key key)107 krb5_k_key_enctype(krb5_context context, krb5_key key)
108 {
109 return key->keyblock.enctype;
110 }
111