1 /*	$NetBSD: crypto-aes.c,v 1.1.1.2 2014/04/24 12:45:49 pettai Exp $	*/
2 
3 /*
4  * Copyright (c) 1997 - 2008 Kungliga Tekniska Högskolan
5  * (Royal Institute of Technology, Stockholm, Sweden).
6  * All rights reserved.
7  *
8  * Redistribution and use in source and binary forms, with or without
9  * modification, are permitted provided that the following conditions
10  * are met:
11  *
12  * 1. Redistributions of source code must retain the above copyright
13  *    notice, this list of conditions and the following disclaimer.
14  *
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * 3. Neither the name of the Institute nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  */
35 
36 #include "krb5_locl.h"
37 
38 /*
39  * AES
40  */
41 
42 static struct _krb5_key_type keytype_aes128 = {
43     ENCTYPE_AES128_CTS_HMAC_SHA1_96,
44     "aes-128",
45     128,
46     16,
47     sizeof(struct _krb5_evp_schedule),
48     NULL,
49     _krb5_evp_schedule,
50     _krb5_AES_salt,
51     NULL,
52     _krb5_evp_cleanup,
53     EVP_aes_128_cbc
54 };
55 
56 static struct _krb5_key_type keytype_aes256 = {
57     ENCTYPE_AES256_CTS_HMAC_SHA1_96,
58     "aes-256",
59     256,
60     32,
61     sizeof(struct _krb5_evp_schedule),
62     NULL,
63     _krb5_evp_schedule,
64     _krb5_AES_salt,
65     NULL,
66     _krb5_evp_cleanup,
67     EVP_aes_256_cbc
68 };
69 
70 struct _krb5_checksum_type _krb5_checksum_hmac_sha1_aes128 = {
71     CKSUMTYPE_HMAC_SHA1_96_AES_128,
72     "hmac-sha1-96-aes128",
73     64,
74     12,
75     F_KEYED | F_CPROOF | F_DERIVED,
76     _krb5_SP_HMAC_SHA1_checksum,
77     NULL
78 };
79 
80 struct _krb5_checksum_type _krb5_checksum_hmac_sha1_aes256 = {
81     CKSUMTYPE_HMAC_SHA1_96_AES_256,
82     "hmac-sha1-96-aes256",
83     64,
84     12,
85     F_KEYED | F_CPROOF | F_DERIVED,
86     _krb5_SP_HMAC_SHA1_checksum,
87     NULL
88 };
89 
90 static krb5_error_code
91 AES_PRF(krb5_context context,
92 	krb5_crypto crypto,
93 	const krb5_data *in,
94 	krb5_data *out)
95 {
96     struct _krb5_checksum_type *ct = crypto->et->checksum;
97     krb5_error_code ret;
98     Checksum result;
99     krb5_keyblock *derived;
100 
101     result.cksumtype = ct->type;
102     ret = krb5_data_alloc(&result.checksum, ct->checksumsize);
103     if (ret) {
104 	krb5_set_error_message(context, ret, N_("malloc: out memory", ""));
105 	return ret;
106     }
107 
108     ret = (*ct->checksum)(context, NULL, in->data, in->length, 0, &result);
109     if (ret) {
110 	krb5_data_free(&result.checksum);
111 	return ret;
112     }
113 
114     if (result.checksum.length < crypto->et->blocksize)
115 	krb5_abortx(context, "internal prf error");
116 
117     derived = NULL;
118     ret = krb5_derive_key(context, crypto->key.key,
119 			  crypto->et->type, "prf", 3, &derived);
120     if (ret)
121 	krb5_abortx(context, "krb5_derive_key");
122 
123     ret = krb5_data_alloc(out, crypto->et->blocksize);
124     if (ret)
125 	krb5_abortx(context, "malloc failed");
126 
127     {
128 	const EVP_CIPHER *c = (*crypto->et->keytype->evp)();
129 	EVP_CIPHER_CTX ctx;
130 
131 	EVP_CIPHER_CTX_init(&ctx); /* ivec all zero */
132 	EVP_CipherInit_ex(&ctx, c, NULL, derived->keyvalue.data, NULL, 1);
133 	EVP_Cipher(&ctx, out->data, result.checksum.data,
134 		   crypto->et->blocksize);
135 	EVP_CIPHER_CTX_cleanup(&ctx);
136     }
137 
138     krb5_data_free(&result.checksum);
139     krb5_free_keyblock(context, derived);
140 
141     return ret;
142 }
143 
144 struct _krb5_encryption_type _krb5_enctype_aes128_cts_hmac_sha1 = {
145     ETYPE_AES128_CTS_HMAC_SHA1_96,
146     "aes128-cts-hmac-sha1-96",
147     16,
148     1,
149     16,
150     &keytype_aes128,
151     &_krb5_checksum_sha1,
152     &_krb5_checksum_hmac_sha1_aes128,
153     F_DERIVED,
154     _krb5_evp_encrypt_cts,
155     16,
156     AES_PRF
157 };
158 
159 struct _krb5_encryption_type _krb5_enctype_aes256_cts_hmac_sha1 = {
160     ETYPE_AES256_CTS_HMAC_SHA1_96,
161     "aes256-cts-hmac-sha1-96",
162     16,
163     1,
164     16,
165     &keytype_aes256,
166     &_krb5_checksum_sha1,
167     &_krb5_checksum_hmac_sha1_aes256,
168     F_DERIVED,
169     _krb5_evp_encrypt_cts,
170     16,
171     AES_PRF
172 };
173