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*/
45 static krb5_error_code
k5_hmac_md5_hash(krb5_context context,const krb5_keyblock * key,krb5_keyusage usage,const krb5_data * iv,const krb5_data * input,krb5_data * output)46 k5_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
138 cleanup:
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
146 krb5int_keyhash_hmac_md5 = {
147 MD5_CKSUM_LENGTH,
148 k5_hmac_md5_hash,
149 NULL /*checksum again*/
150 };
151
152