1 /*
2  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 
7 /*
8  * Copyright (C) 1998 by the FundsXpress, INC.
9  *
10  * All rights reserved.
11  *
12  * Export of this software from the United States of America may require
13  * a specific license from the United States Government.  It is the
14  * responsibility of any person or organization contemplating export to
15  * obtain such a license before exporting.
16  *
17  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
18  * distribute this software and its documentation for any purpose and
19  * without fee is hereby granted, provided that the above copyright
20  * notice appear in all copies and that both that copyright notice and
21  * this permission notice appear in supporting documentation, and that
22  * the name of FundsXpress. not be used in advertising or publicity pertaining
23  * to distribution of the software without specific, written prior
24  * permission.  FundsXpress makes no representations about the suitability of
25  * this software for any purpose.  It is provided "as is" without express
26  * or implied warranty.
27  *
28  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
29  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
30  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
31  */
32 
33 #include "k5-int.h"
34 
35 /* Solaris Kerberos */
36 #ifdef _KERNEL
37 /*
38  * In kernel, use the Kernel encryption framework HMAC
39  * operation, its far more efficient than the MIT method.
40  * Also, a template is used to further improve performance.
41  */
42 /* ARGSUSED */
43 krb5_error_code
44 krb5_hmac(krb5_context context, const krb5_keyblock *key,
45 	krb5_const krb5_data *input, krb5_data *output)
46 {
47 	int rv = CRYPTO_FAILED;
48         crypto_mechanism_t mac_mech;
49 	crypto_data_t dd;
50 	crypto_data_t mac;
51 
52 	KRB5_LOG0(KRB5_INFO, "krb5_hmac() start");
53 	if (output == NULL || output->data == NULL) {
54 		KRB5_LOG0(KRB5_INFO, "krb5_hmac() NULL output");
55 		return (rv);
56 	}
57 	if (input == NULL || input->data == NULL) {
58 		KRB5_LOG0(KRB5_INFO, "krb5_hmac() NULL input");
59 		return (rv);
60 	}
61 
62 	dd.cd_format = CRYPTO_DATA_RAW;
63 	dd.cd_offset = 0;
64 	dd.cd_length = input->length;
65 	dd.cd_raw.iov_base = (char *)input->data;
66 	dd.cd_raw.iov_len = input->length;
67 
68 	mac.cd_format = CRYPTO_DATA_RAW;
69 	mac.cd_offset = 0;
70 	mac.cd_length = output->length;
71 	mac.cd_raw.iov_base = (char *)output->data;
72 	mac.cd_raw.iov_len = output->length;
73 
74 	mac_mech.cm_type = context->kef_hash_mt;
75 	mac_mech.cm_param = NULL;
76 	mac_mech.cm_param_len = 0;
77 
78 	rv = crypto_mac(&mac_mech, &dd,
79 			(crypto_key_t *)&key->kef_key,
80 			key->key_tmpl, &mac, NULL);
81 
82 	if (rv != CRYPTO_SUCCESS) {
83 		KRB5_LOG(KRB5_ERR,"crypto_mac error: %0x", rv);
84 	}
85 
86 	KRB5_LOG(KRB5_INFO, "krb5_hmac() end ret=%d\n", rv);
87 	return(rv);
88 }
89 
90 #else
91 /* Userland implementation of HMAC algorithm */
92 
93 /*
94  * the HMAC transform looks like:
95  *
96  * H(K XOR opad, H(K XOR ipad, text))
97  *
98  * where H is a cryptographic hash
99  * K is an n byte key
100  * ipad is the byte 0x36 repeated blocksize times
101  * opad is the byte 0x5c repeated blocksize times
102  * and text is the data being protected
103  */
104 
105 krb5_error_code
106 krb5_hmac(krb5_context context,
107 	krb5_const struct krb5_hash_provider *hash,
108 	krb5_const krb5_keyblock *key,
109 	krb5_const unsigned int icount,
110 	krb5_const krb5_data *input,
111 	krb5_data *output)
112 {
113     size_t hashsize, blocksize;
114     unsigned char *xorkey, *ihash;
115     int i;
116     krb5_data *hashin, hashout;
117     krb5_error_code ret;
118 
119     /* Solaris Kerberos */
120     KRB5_LOG0(KRB5_INFO, "krb5_hmac() start\n");
121 
122     if (hash == NULL) {
123 	KRB5_LOG0(KRB5_ERR, "krb5_hmac() error hash == NULL\n");
124 	return(EINVAL);
125     }
126     if (key == NULL) {
127 	KRB5_LOG0(KRB5_ERR, "krb5_hmac() error key == NULL\n");
128 	return(EINVAL);
129     }
130     if (input == NULL) {
131 	KRB5_LOG0(KRB5_ERR, "krb5_hmac() error input == NULL\n");
132 	return(EINVAL);
133     }
134     if (output == NULL) {
135 	KRB5_LOG0(KRB5_ERR, "krb5_hmac() error output == NULL\n");
136 	return(EINVAL);
137     }
138 
139     hashsize = hash->hashsize;
140     blocksize = hash->blocksize;
141 
142     if (key->length > blocksize)
143 	return(KRB5_CRYPTO_INTERNAL);
144     if (output->length < hashsize)
145 	return(KRB5_BAD_MSIZE);
146     /* if this isn't > 0, then there won't be enough space in this
147        array to compute the outer hash */
148     if (icount == 0)
149 	return(KRB5_CRYPTO_INTERNAL);
150 
151     /* allocate space for the xor key, hash input vector, and inner hash */
152 
153     if ((xorkey = (unsigned char *) MALLOC(blocksize)) == NULL)
154 	return(ENOMEM);
155     if ((ihash = (unsigned char *) MALLOC(hashsize)) == NULL) {
156 	FREE(xorkey, blocksize);
157 	return(ENOMEM);
158     }
159     if ((hashin = (krb5_data *)MALLOC(sizeof(krb5_data)*(icount+1))) == NULL) {
160 	FREE(ihash, hashsize);
161 	FREE(xorkey, blocksize);
162 	return(ENOMEM);
163     }
164 
165     /* create the inner padded key */
166 
167     /* Solaris Kerberos */
168     (void) memset(xorkey, 0x36, blocksize);
169 
170     for (i=0; i<key->length; i++)
171 	xorkey[i] ^= key->contents[i];
172 
173     /* compute the inner hash */
174 
175     for (i=0; i<icount; i++) {
176 	hashin[0].length = blocksize;
177 	hashin[0].data = (char *) xorkey;
178 	hashin[i+1] = input[i];
179     }
180 
181     hashout.length = hashsize;
182     hashout.data = (char *) ihash;
183 
184     /* Solaris Kerberos */
185     if ((ret = ((*(hash->hash))(context, icount+1, hashin, &hashout))))
186 	goto cleanup;
187 
188     /* create the outer padded key */
189 
190     /* Solaris Kerberos */
191     (void) memset(xorkey, 0x5c, blocksize);
192 
193     for (i=0; i<key->length; i++)
194 	xorkey[i] ^= key->contents[i];
195 
196     /* compute the outer hash */
197 
198     hashin[0].length = blocksize;
199     hashin[0].data = (char *) xorkey;
200     hashin[1] = hashout;
201 
202     output->length = hashsize;
203 
204     /* Solaris Kerberos */
205     if ((ret = ((*(hash->hash))(context, 2, hashin, output))))
206 	(void) memset(output->data, 0, output->length);
207 
208     /* ret is set correctly by the prior call */
209 
210 cleanup:
211     /* Solaris Kerberos */
212     (void) memset(xorkey, 0, blocksize);
213     (void) memset(ihash, 0, hashsize);
214 
215     FREE(hashin, sizeof(krb5_data)*(icount+1));
216     FREE(ihash, hashsize);
217     FREE(xorkey, blocksize);
218 
219     /* Solaris Kerberos */
220     KRB5_LOG(KRB5_INFO, "krb5_hmac() end ret=%d\n", ret);
221     return(ret);
222 }
223 #endif /* _KERNEL */
224