2 * Copyright 2011-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
10 #include <openssl/crypto.h>
11 #include "modes_lcl.h"
14 int CRYPTO_xts128_encrypt(const XTS128_CONTEXT *ctx,
15 const unsigned char iv[16],
16 const unsigned char *inp, unsigned char *out,
35 memcpy(tweak.c, iv, 16);
37 (*ctx->block2) (tweak.c, tweak.c, ctx->key2);
39 if (!enc && (len % 16))
43 #if defined(STRICT_ALIGNMENT)
44 memcpy(scratch.c, inp, 16);
45 scratch.u[0] ^= tweak.u[0];
46 scratch.u[1] ^= tweak.u[1];
48 scratch.u[0] = ((u64 *)inp)[0] ^ tweak.u[0];
49 scratch.u[1] = ((u64 *)inp)[1] ^ tweak.u[1];
51 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
52 #if defined(STRICT_ALIGNMENT)
53 scratch.u[0] ^= tweak.u[0];
54 scratch.u[1] ^= tweak.u[1];
55 memcpy(out, scratch.c, 16);
57 ((u64 *)out)[0] = scratch.u[0] ^= tweak.u[0];
58 ((u64 *)out)[1] = scratch.u[1] ^= tweak.u[1];
67 if (is_endian.little) {
68 unsigned int carry, res;
70 res = 0x87 & (((int)tweak.d[3]) >> 31);
71 carry = (unsigned int)(tweak.u[0] >> 63);
72 tweak.u[0] = (tweak.u[0] << 1) ^ res;
73 tweak.u[1] = (tweak.u[1] << 1) | carry;
77 for (c = 0, i = 0; i < 16; ++i) {
79 * + substitutes for |, because c is 1 bit
81 c += ((size_t)tweak.c[i]) << 1;
85 tweak.c[0] ^= (u8)(0x87 & (0 - c));
89 for (i = 0; i < len; ++i) {
91 out[i] = scratch.c[i];
94 scratch.u[0] ^= tweak.u[0];
95 scratch.u[1] ^= tweak.u[1];
96 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
97 scratch.u[0] ^= tweak.u[0];
98 scratch.u[1] ^= tweak.u[1];
99 memcpy(out - 16, scratch.c, 16);
106 if (is_endian.little) {
107 unsigned int carry, res;
109 res = 0x87 & (((int)tweak.d[3]) >> 31);
110 carry = (unsigned int)(tweak.u[0] >> 63);
111 tweak1.u[0] = (tweak.u[0] << 1) ^ res;
112 tweak1.u[1] = (tweak.u[1] << 1) | carry;
116 for (c = 0, i = 0; i < 16; ++i) {
118 * + substitutes for |, because c is 1 bit
120 c += ((size_t)tweak.c[i]) << 1;
124 tweak1.c[0] ^= (u8)(0x87 & (0 - c));
126 #if defined(STRICT_ALIGNMENT)
127 memcpy(scratch.c, inp, 16);
128 scratch.u[0] ^= tweak1.u[0];
129 scratch.u[1] ^= tweak1.u[1];
131 scratch.u[0] = ((u64 *)inp)[0] ^ tweak1.u[0];
132 scratch.u[1] = ((u64 *)inp)[1] ^ tweak1.u[1];
134 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
135 scratch.u[0] ^= tweak1.u[0];
136 scratch.u[1] ^= tweak1.u[1];
138 for (i = 0; i < len; ++i) {
140 out[16 + i] = scratch.c[i];
143 scratch.u[0] ^= tweak.u[0];
144 scratch.u[1] ^= tweak.u[1];
145 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
146 #if defined(STRICT_ALIGNMENT)
147 scratch.u[0] ^= tweak.u[0];
148 scratch.u[1] ^= tweak.u[1];
149 memcpy(out, scratch.c, 16);
151 ((u64 *)out)[0] = scratch.u[0] ^ tweak.u[0];
152 ((u64 *)out)[1] = scratch.u[1] ^ tweak.u[1];