1 /* -*- mode: c; c-basic-offset: 4; indent-tabs-mode: nil -*- */
2 /* lib/crypto/krb/prf.c */
3 /*
4 * Copyright (C) 2004 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 /*
28 * This contains the implementation of krb5_c_prf, which will find the
29 * enctype-specific PRF and then generate pseudo-random data. This function
30 * yields krb5_c_prf_length bytes of output.
31 */
32
33 #include "crypto_int.h"
34
35 krb5_error_code KRB5_CALLCONV
krb5_c_prf_length(krb5_context context,krb5_enctype enctype,size_t * len)36 krb5_c_prf_length(krb5_context context, krb5_enctype enctype, size_t *len)
37 {
38 const struct krb5_keytypes *ktp;
39
40 assert(len);
41 ktp = find_enctype(enctype);
42 if (ktp == NULL)
43 return KRB5_BAD_ENCTYPE;
44 *len = ktp->prf_length;
45 return 0;
46 }
47
48 krb5_error_code KRB5_CALLCONV
krb5_k_prf(krb5_context context,krb5_key key,krb5_data * input,krb5_data * output)49 krb5_k_prf(krb5_context context, krb5_key key,
50 krb5_data *input, krb5_data *output)
51 {
52 const struct krb5_keytypes *ktp;
53 krb5_error_code ret;
54
55 assert(input && output);
56 assert(output->data);
57
58 ktp = find_enctype(key->keyblock.enctype);
59 if (ktp == NULL)
60 return KRB5_BAD_ENCTYPE;
61 if (ktp->prf == NULL)
62 return KRB5_CRYPTO_INTERNAL;
63
64 output->magic = KV5M_DATA;
65 if (ktp->prf_length != output->length)
66 return KRB5_CRYPTO_INTERNAL;
67 ret = ktp->prf(ktp, key, input, output);
68 return ret;
69 }
70
71 krb5_error_code KRB5_CALLCONV
krb5_c_prf(krb5_context context,const krb5_keyblock * keyblock,krb5_data * input,krb5_data * output)72 krb5_c_prf(krb5_context context, const krb5_keyblock *keyblock,
73 krb5_data *input, krb5_data *output)
74 {
75 krb5_key key;
76 krb5_error_code ret;
77
78 ret = krb5_k_create_key(context, keyblock, &key);
79 if (ret != 0)
80 return ret;
81 ret = krb5_k_prf(context, key, input, output);
82 krb5_k_free_key(context, key);
83 return ret;
84 }
85