1 /* $OpenBSD: aes_ige.c,v 1.8 2022/01/22 00:43:41 inoguchi Exp $ */
2 /* ====================================================================
3 * Copyright (c) 2006 The OpenSSL Project. All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in
14 * the documentation and/or other materials provided with the
15 * distribution.
16 *
17 * 3. All advertising materials mentioning features or use of this
18 * software must display the following acknowledgment:
19 * "This product includes software developed by the OpenSSL Project
20 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
21 *
22 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
23 * endorse or promote products derived from this software without
24 * prior written permission. For written permission, please contact
25 * openssl-core@openssl.org.
26 *
27 * 5. Products derived from this software may not be called "OpenSSL"
28 * nor may "OpenSSL" appear in their names without prior written
29 * permission of the OpenSSL Project.
30 *
31 * 6. Redistributions of any form whatsoever must retain the following
32 * acknowledgment:
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
35 *
36 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
37 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
38 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
39 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
40 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
42 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
43 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
44 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
45 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
46 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
47 * OF THE POSSIBILITY OF SUCH DAMAGE.
48 * ====================================================================
49 *
50 */
51
52 #include <openssl/aes.h>
53 #include <openssl/crypto.h>
54
55 #include "aes_locl.h"
56
57 #define N_WORDS (AES_BLOCK_SIZE / sizeof(unsigned long))
58 typedef struct {
59 unsigned long data[N_WORDS];
60 } aes_block_t;
61
62 /* XXX: probably some better way to do this */
63 #if defined(__i386__) || defined(__x86_64__)
64 #define UNALIGNED_MEMOPS_ARE_FAST 1
65 #else
66 #define UNALIGNED_MEMOPS_ARE_FAST 0
67 #endif
68
69 #if UNALIGNED_MEMOPS_ARE_FAST
70 #define load_block(d, s) (d) = *(const aes_block_t *)(s)
71 #define store_block(d, s) *(aes_block_t *)(d) = (s)
72 #else
73 #define load_block(d, s) memcpy((d).data, (s), AES_BLOCK_SIZE)
74 #define store_block(d, s) memcpy((d), (s).data, AES_BLOCK_SIZE)
75 #endif
76
77 /* N.B. The IV for this mode is _twice_ the block size */
78
79 void
AES_ige_encrypt(const unsigned char * in,unsigned char * out,size_t length,const AES_KEY * key,unsigned char * ivec,const int enc)80 AES_ige_encrypt(const unsigned char *in, unsigned char *out, size_t length,
81 const AES_KEY *key, unsigned char *ivec, const int enc)
82 {
83 size_t n;
84 size_t len;
85
86 OPENSSL_assert((length % AES_BLOCK_SIZE) == 0);
87
88 len = length / AES_BLOCK_SIZE;
89
90 if (AES_ENCRYPT == enc) {
91 if (in != out && (UNALIGNED_MEMOPS_ARE_FAST ||
92 ((size_t)in|(size_t)out|(size_t)ivec) %
93 sizeof(long) == 0)) {
94 aes_block_t *ivp = (aes_block_t *)ivec;
95 aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
96
97 while (len) {
98 aes_block_t *inp = (aes_block_t *)in;
99 aes_block_t *outp = (aes_block_t *)out;
100
101 for (n = 0; n < N_WORDS; ++n)
102 outp->data[n] = inp->data[n] ^ ivp->data[n];
103 AES_encrypt((unsigned char *)outp->data, (unsigned char *)outp->data, key);
104 for (n = 0; n < N_WORDS; ++n)
105 outp->data[n] ^= iv2p->data[n];
106 ivp = outp;
107 iv2p = inp;
108 --len;
109 in += AES_BLOCK_SIZE;
110 out += AES_BLOCK_SIZE;
111 }
112 memmove(ivec, ivp->data, AES_BLOCK_SIZE);
113 memmove(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
114 } else {
115 aes_block_t tmp, tmp2;
116 aes_block_t iv;
117 aes_block_t iv2;
118
119 load_block(iv, ivec);
120 load_block(iv2, ivec + AES_BLOCK_SIZE);
121
122 while (len) {
123 load_block(tmp, in);
124 for (n = 0; n < N_WORDS; ++n)
125 tmp2.data[n] = tmp.data[n] ^ iv.data[n];
126 AES_encrypt((unsigned char *)tmp2.data,
127 (unsigned char *)tmp2.data, key);
128 for (n = 0; n < N_WORDS; ++n)
129 tmp2.data[n] ^= iv2.data[n];
130 store_block(out, tmp2);
131 iv = tmp2;
132 iv2 = tmp;
133 --len;
134 in += AES_BLOCK_SIZE;
135 out += AES_BLOCK_SIZE;
136 }
137 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
138 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
139 }
140 } else {
141 if (in != out && (UNALIGNED_MEMOPS_ARE_FAST ||
142 ((size_t)in|(size_t)out|(size_t)ivec) %
143 sizeof(long) == 0)) {
144 aes_block_t *ivp = (aes_block_t *)ivec;
145 aes_block_t *iv2p = (aes_block_t *)(ivec + AES_BLOCK_SIZE);
146
147 while (len) {
148 aes_block_t tmp;
149 aes_block_t *inp = (aes_block_t *)in;
150 aes_block_t *outp = (aes_block_t *)out;
151
152 for (n = 0; n < N_WORDS; ++n)
153 tmp.data[n] = inp->data[n] ^ iv2p->data[n];
154 AES_decrypt((unsigned char *)tmp.data,
155 (unsigned char *)outp->data, key);
156 for (n = 0; n < N_WORDS; ++n)
157 outp->data[n] ^= ivp->data[n];
158 ivp = inp;
159 iv2p = outp;
160 --len;
161 in += AES_BLOCK_SIZE;
162 out += AES_BLOCK_SIZE;
163 }
164 memmove(ivec, ivp->data, AES_BLOCK_SIZE);
165 memmove(ivec + AES_BLOCK_SIZE, iv2p->data, AES_BLOCK_SIZE);
166 } else {
167 aes_block_t tmp, tmp2;
168 aes_block_t iv;
169 aes_block_t iv2;
170
171 load_block(iv, ivec);
172 load_block(iv2, ivec + AES_BLOCK_SIZE);
173
174 while (len) {
175 load_block(tmp, in);
176 tmp2 = tmp;
177 for (n = 0; n < N_WORDS; ++n)
178 tmp.data[n] ^= iv2.data[n];
179 AES_decrypt((unsigned char *)tmp.data,
180 (unsigned char *)tmp.data, key);
181 for (n = 0; n < N_WORDS; ++n)
182 tmp.data[n] ^= iv.data[n];
183 store_block(out, tmp);
184 iv = tmp2;
185 iv2 = tmp;
186 --len;
187 in += AES_BLOCK_SIZE;
188 out += AES_BLOCK_SIZE;
189 }
190 memcpy(ivec, iv.data, AES_BLOCK_SIZE);
191 memcpy(ivec + AES_BLOCK_SIZE, iv2.data, AES_BLOCK_SIZE);
192 }
193 }
194 }
195