1 /*
2  * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
3  * Use is subject to license terms.
4  */
5 
6 /*
7  * Copyright (C) 1998 by the FundsXpress, INC.
8  *
9  * All rights reserved.
10  *
11  * Export of this software from the United States of America may require
12  * a specific license from the United States Government.  It is the
13  * responsibility of any person or organization contemplating export to
14  * obtain such a license before exporting.
15  *
16  * WITHIN THAT CONSTRAINT, permission to use, copy, modify, and
17  * distribute this software and its documentation for any purpose and
18  * without fee is hereby granted, provided that the above copyright
19  * notice appear in all copies and that both that copyright notice and
20  * this permission notice appear in supporting documentation, and that
21  * the name of FundsXpress. not be used in advertising or publicity pertaining
22  * to distribution of the software without specific, written prior
23  * permission.  FundsXpress makes no representations about the suitability of
24  * this software for any purpose.  It is provided "as is" without express
25  * or implied warranty.
26  *
27  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
28  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
29  * WARRANTIES OF MERCHANTIBILITY AND FITNESS FOR A PARTICULAR PURPOSE.
30  */
31 
32 #include "k5-int.h"
33 #include "cksumtypes.h"
34 #include "etypes.h"
35 #include "dk.h"
36 
37 krb5_error_code KRB5_CALLCONV
krb5_c_make_checksum(krb5_context context,krb5_cksumtype cksumtype,const krb5_keyblock * key,krb5_keyusage usage,const krb5_data * input,krb5_checksum * cksum)38 krb5_c_make_checksum(krb5_context context, krb5_cksumtype cksumtype,
39 		     const krb5_keyblock *key, krb5_keyusage usage,
40 		     const krb5_data *input, krb5_checksum *cksum)
41 {
42     int i, e1, e2;
43     krb5_data data;
44     krb5_error_code ret = 0;
45     size_t cksumlen;
46 
47     KRB5_LOG0(KRB5_INFO, "krb5_c_make_checksum() start.");
48 
49     for (i=0; i<krb5_cksumtypes_length; i++) {
50 	if (krb5_cksumtypes_list[i].ctype == cksumtype)
51 	    break;
52     }
53 
54     if (i == krb5_cksumtypes_length)
55 	return(KRB5_BAD_ENCTYPE);
56 
57     if (krb5_cksumtypes_list[i].keyhash)
58 	cksumlen = krb5_cksumtypes_list[i].keyhash->hashsize;
59     else
60 	cksumlen = krb5_cksumtypes_list[i].hash->hashsize;
61 
62 #ifdef _KERNEL
63     context->kef_cksum_mt = krb5_cksumtypes_list[i].kef_cksum_mt;
64 #endif
65     cksum->length = cksumlen;
66 
67     if ((cksum->contents = (krb5_octet *) MALLOC(cksum->length)) == NULL)
68 	return(ENOMEM);
69 
70     data.length = cksum->length;
71     data.data = (char *) cksum->contents;
72 
73     if (krb5_cksumtypes_list[i].keyhash) {
74 	/* check if key is compatible */
75 
76 	if (krb5_cksumtypes_list[i].keyed_etype) {
77 	    for (e1=0; e1<krb5_enctypes_length; e1++)
78 		if (krb5_enctypes_list[e1].etype ==
79 		    krb5_cksumtypes_list[i].keyed_etype)
80 		    break;
81 
82 	    for (e2=0; e2<krb5_enctypes_length; e2++)
83 		if (krb5_enctypes_list[e2].etype == key->enctype)
84 		    break;
85 
86 	    /*
87 	     * Solaris Kerberos: The actual key encryption type could be
88 	     * arbitrary, so the checksum enc type doesn't need to be the same.
89 	     */
90 	    if ((e1 == krb5_enctypes_length) || (e2 == krb5_enctypes_length)) {
91 		ret = KRB5_BAD_ENCTYPE;
92 		goto cleanup;
93 	    }
94 	}
95 #ifdef _KERNEL
96 	context->kef_cipher_mt = krb5_enctypes_list[e1].kef_cipher_mt;
97 	context->kef_hash_mt = krb5_enctypes_list[e1].kef_hash_mt;
98 	if (key->kef_key.ck_data == NULL) {
99 		if ((ret = init_key_kef(context->kef_cipher_mt,
100 				(krb5_keyblock *)key)))
101 			goto cleanup;
102 	}
103 #else
104 	if ((ret = init_key_uef(krb_ctx_hSession(context), (krb5_keyblock *)key)))
105 		return (ret);
106 #endif /* _KERNEL */
107 
108 	ret = (*(krb5_cksumtypes_list[i].keyhash->hash))(context, key,
109 						usage, 0, input, &data);
110     } else if (krb5_cksumtypes_list[i].flags & KRB5_CKSUMFLAG_DERIVE) {
111 #ifdef _KERNEL
112     	context->kef_cipher_mt = get_cipher_mech_type(context,
113 					(krb5_keyblock *)key);
114     	context->kef_hash_mt = get_hash_mech_type(context,
115 					(krb5_keyblock *)key);
116 	/*
117 	 * If the hash_mt is invalid, try using the cksum_mt
118 	 * because "hash" and "checksum" are overloaded terms
119 	 * in some places.
120 	 */
121 	if (context->kef_hash_mt == CRYPTO_MECH_INVALID)
122 		context->kef_hash_mt = context->kef_cksum_mt;
123 #else
124 	ret = init_key_uef(krb_ctx_hSession(context), (krb5_keyblock *)key);
125 	if (ret)
126 		return (ret);
127 #endif /* _KERNEL */
128 	ret = krb5_dk_make_checksum(context,
129 				krb5_cksumtypes_list[i].hash,
130 				key, usage, input, &data);
131     } else {
132 	    /*
133 	     * No key is used, hash and cksum are synonymous
134 	     * in this case
135 	     */
136 #ifdef _KERNEL
137 	    context->kef_hash_mt = context->kef_cksum_mt;
138 #endif /* _KERNEL */
139 	    ret = (*(krb5_cksumtypes_list[i].hash->hash))(context, 1,
140 							input, &data);
141     }
142 
143     if (!ret) {
144 	cksum->magic = KV5M_CHECKSUM;
145 	cksum->checksum_type = cksumtype;
146 	if (krb5_cksumtypes_list[i].trunc_size) {
147 	    krb5_octet *trunc;
148             size_t old_len = cksum->length;
149 
150             /*
151              * Solaris Kerberos:
152              * The Kernel does not like 'realloc' (which is what
153              * MIT code does here), so we do our own "realloc".
154              */
155             cksum->length = krb5_cksumtypes_list[i].trunc_size;
156             trunc = (krb5_octet *) MALLOC(cksum->length);
157             if (trunc) {
158                 (void) memcpy(trunc, cksum->contents, cksum->length);
159                 FREE(cksum->contents, old_len);
160                 cksum->contents = trunc;
161             } else {
162                 ret = ENOMEM;
163             }
164         }
165     }
166 
167 cleanup:
168     if (ret) {
169 	(void) memset(cksum->contents, 0, cksum->length);
170 	FREE(cksum->contents, cksum->length);
171 	cksum->length = 0;
172 	cksum->contents = NULL;
173     }
174 
175     KRB5_LOG(KRB5_INFO, "krb5_c_make_checksum() end ret = %d\n", ret);
176     return(ret);
177 }
178