1 /* $OpenBSD: xts128.c,v 1.7 2017/08/13 17:46:24 bcook Exp $ */
2 /* ====================================================================
3 * Copyright (c) 2011 The OpenSSL Project. All rights reserved.
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
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
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/)"
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.
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.
31 * 6. Redistributions of any form whatsoever must retain the following
33 * "This product includes software developed by the OpenSSL Project
34 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
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 * ====================================================================
51 #include <machine/endian.h>
52 #include <openssl/crypto.h>
53 #include "modes_lcl.h"
62 int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx, const unsigned char iv[16],
63 const unsigned char *inp, unsigned char *out,
66 union { u64 u[2]; u32 d[4]; u8 c[16]; } tweak, scratch;
69 if (len<16) return -1;
71 memcpy(tweak.c, iv, 16);
73 (*ctx->block2)(tweak.c,tweak.c,ctx->key2);
75 if (!enc && (len%16)) len-=16;
78 #ifdef __STRICT_ALIGNMENT
79 memcpy(scratch.c,inp,16);
80 scratch.u[0] ^= tweak.u[0];
81 scratch.u[1] ^= tweak.u[1];
83 scratch.u[0] = ((u64*)inp)[0]^tweak.u[0];
84 scratch.u[1] = ((u64*)inp)[1]^tweak.u[1];
86 (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
87 #ifdef __STRICT_ALIGNMENT
88 scratch.u[0] ^= tweak.u[0];
89 scratch.u[1] ^= tweak.u[1];
90 memcpy(out,scratch.c,16);
92 ((u64*)out)[0] = scratch.u[0]^=tweak.u[0];
93 ((u64*)out)[1] = scratch.u[1]^=tweak.u[1];
101 #if BYTE_ORDER == LITTLE_ENDIAN
102 unsigned int carry,res;
104 res = 0x87&(((int)tweak.d[3])>>31);
105 carry = (unsigned int)(tweak.u[0]>>63);
106 tweak.u[0] = (tweak.u[0]<<1)^res;
107 tweak.u[1] = (tweak.u[1]<<1)|carry;
108 #else /* BIG_ENDIAN */
111 for (c=0,i=0;i<16;++i) {
112 /*+ substitutes for |, because c is 1 bit */
113 c += ((size_t)tweak.c[i])<<1;
117 tweak.c[0] ^= (u8)(0x87&(0-c));
121 for (i=0;i<len;++i) {
123 out[i] = scratch.c[i];
126 scratch.u[0] ^= tweak.u[0];
127 scratch.u[1] ^= tweak.u[1];
128 (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
129 scratch.u[0] ^= tweak.u[0];
130 scratch.u[1] ^= tweak.u[1];
131 memcpy(out-16,scratch.c,16);
134 union { u64 u[2]; u8 c[16]; } tweak1;
136 #if BYTE_ORDER == LITTLE_ENDIAN
137 unsigned int carry,res;
139 res = 0x87&(((int)tweak.d[3])>>31);
140 carry = (unsigned int)(tweak.u[0]>>63);
141 tweak1.u[0] = (tweak.u[0]<<1)^res;
142 tweak1.u[1] = (tweak.u[1]<<1)|carry;
146 for (c=0,i=0;i<16;++i) {
147 /*+ substitutes for |, because c is 1 bit */
148 c += ((size_t)tweak.c[i])<<1;
152 tweak1.c[0] ^= (u8)(0x87&(0-c));
154 #ifdef __STRICT_ALIGNMENT
155 memcpy(scratch.c,inp,16);
156 scratch.u[0] ^= tweak1.u[0];
157 scratch.u[1] ^= tweak1.u[1];
159 scratch.u[0] = ((u64*)inp)[0]^tweak1.u[0];
160 scratch.u[1] = ((u64*)inp)[1]^tweak1.u[1];
162 (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
163 scratch.u[0] ^= tweak1.u[0];
164 scratch.u[1] ^= tweak1.u[1];
166 for (i=0;i<len;++i) {
168 out[16+i] = scratch.c[i];
171 scratch.u[0] ^= tweak.u[0];
172 scratch.u[1] ^= tweak.u[1];
173 (*ctx->block1)(scratch.c,scratch.c,ctx->key1);
174 #ifdef __STRICT_ALIGNMENT
175 scratch.u[0] ^= tweak.u[0];
176 scratch.u[1] ^= tweak.u[1];
177 memcpy (out,scratch.c,16);
179 ((u64*)out)[0] = scratch.u[0]^tweak.u[0];
180 ((u64*)out)[1] = scratch.u[1]^tweak.u[1];