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
37krb5_error_code KRB5_CALLCONV
38krb5_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
167cleanup:
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