1/*
2 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3 * Use is subject to license terms.
4 */
5
6/*
7 * lib/crypto/keyhash_provider/hmac_md5.c
8 *
9(I don't know)
10.
11 * Copyright2001 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* Implementation of the Microsoft hmac-md5 checksum type.
35* Implemented based on draft-brezak-win2k-krb-rc4-hmac-03
36 */
37
38#include <k5-int.h>
39#include <etypes.h>
40#include <keyhash_provider.h>
41#include <arcfour.h>
42#include <hash_provider.h>
43
44/*ARGSUSED*/
45static  krb5_error_code
46k5_hmac_md5_hash (krb5_context context,
47	const krb5_keyblock *key, krb5_keyusage usage,
48	const krb5_data *iv,
49	const krb5_data *input, krb5_data *output)
50{
51  krb5_keyusage ms_usage;
52  krb5_error_code ret;
53  krb5_keyblock ks;
54  krb5_data ds, ks_constant, md5tmp;
55  krb5_data hash_input[2];
56  int i;
57  char t[4], outbuf[MD5_CKSUM_LENGTH];
58
59#ifdef _KERNEL
60  KRB5_LOG1(KRB5_INFO, "k5_hmac_md5_hash() hash_mt = %ld cipher_mt = %ld",
61	(ulong_t) context->kef_hash_mt,
62	(ulong_t) context->kef_cipher_mt);
63#endif
64
65  for (i=0; i<krb5_enctypes_length; i++) {
66	if (krb5_enctypes_list[i].etype == key->enctype)
67            break;
68  }
69  if (i == krb5_enctypes_length) {
70	KRB5_LOG(KRB5_ERR, "krb5_ck_make_checksum bad enctype: %d",
71		key->enctype);
72	return(KRB5_BAD_ENCTYPE);
73  }
74
75  bzero(&ks, sizeof(krb5_keyblock));
76  /*
77   * Solaris Kerberos: The digest length is that of MD5_CKSUM_LENGTH not the key
78   * length, as keys can be of varying lengths but should not affect the digest
79   * length.  The signing key is the digest and therefore is also the same
80   * length, MD5_CKSUM_LENGTH.
81   */
82  ds.length = MD5_CKSUM_LENGTH;
83  ds.data = MALLOC(ds.length);
84  if (ds.data == NULL)
85    return (ENOMEM);
86  ks.contents = (void *) ds.data;
87  ks.length = MD5_CKSUM_LENGTH;
88
89#ifdef _KERNEL
90  if (key->kef_key.ck_data == NULL) {
91	ret = init_key_kef(krb5_enctypes_list[i].kef_cipher_mt,
92			(krb5_keyblock *)key);
93	if (ret)
94		goto cleanup;
95  }
96
97  ret = init_key_kef(krb5_enctypes_list[i].kef_cipher_mt, &ks);
98  if (ret)
99	goto cleanup;
100#endif /* _KERNEL */
101
102  ks_constant.data = "signaturekey";
103  ks_constant.length = strlen(ks_constant.data)+1; /* Including null*/
104
105#ifdef _KERNEL
106  ret = krb5_hmac(context, (krb5_keyblock *)key, &ks_constant, &ds);
107#else
108  ret = krb5_hmac(context, &krb5int_hash_md5, key, 1, &ks_constant, &ds);
109#endif /* _KERNEL */
110  if (ret)
111    goto cleanup;
112
113  ms_usage = krb5int_arcfour_translate_usage (usage);
114  t[0] = (ms_usage) & 0xff;
115  t[1] = (ms_usage>>8) & 0xff;
116  t[2] = (ms_usage >>16) & 0xff;
117  t[3] = (ms_usage>>24) & 0XFF;
118
119  hash_input[0].data = (char *)&t;
120  hash_input[0].length = 4;
121  hash_input[1].data = input->data;
122  hash_input[1].length = input->length;
123
124  md5tmp.data = (void *)outbuf;
125  md5tmp.length = sizeof(outbuf);
126
127  /* Use generic hash function that calls to kEF */
128  if (k5_ef_hash(context, 2, hash_input, &md5tmp)) {
129	return (KRB5_KEF_ERROR);
130  }
131
132#ifdef _KERNEL
133  ret = krb5_hmac (context, &ks, &md5tmp, output);
134#else
135  ret = krb5_hmac (context, &krb5int_hash_md5, &ks, 1, &md5tmp, output);
136#endif /* _KERNEL */
137
138cleanup:
139  bzero(md5tmp.data, md5tmp.length);
140  bzero(ks.contents, ks.length);
141  FREE (ks.contents, ks.length);
142  return (ret);
143}
144
145 const struct krb5_keyhash_provider
146krb5int_keyhash_hmac_md5 = {
147                	MD5_CKSUM_LENGTH,
148			k5_hmac_md5_hash,
149			NULL /*checksum  again*/
150			};
151
152