1 /*
2 * Copyright 2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (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
8 */
9
10 #include <string.h>
11 #include <openssl/crypto.h>
12 #include "internal/endian.h"
13 #include "crypto/modes.h"
14
15 #ifndef STRICT_ALIGNMENT
16 # ifdef __GNUC__
17 typedef u64 u64_a1 __attribute((__aligned__(1)));
18 # else
19 typedef u64 u64_a1;
20 # endif
21 #endif
22
ossl_crypto_xts128gb_encrypt(const XTS128_CONTEXT * ctx,const unsigned char iv[16],const unsigned char * inp,unsigned char * out,size_t len,int enc)23 int ossl_crypto_xts128gb_encrypt(const XTS128_CONTEXT *ctx,
24 const unsigned char iv[16],
25 const unsigned char *inp, unsigned char *out,
26 size_t len, int enc)
27 {
28 DECLARE_IS_ENDIAN;
29 union {
30 u64 u[2];
31 u32 d[4];
32 u8 c[16];
33 } tweak, scratch;
34 unsigned int i;
35
36 if (len < 16)
37 return -1;
38
39 memcpy(tweak.c, iv, 16);
40
41 (*ctx->block2) (tweak.c, tweak.c, ctx->key2);
42
43 if (!enc && (len % 16))
44 len -= 16;
45
46 while (len >= 16) {
47 #if defined(STRICT_ALIGNMENT)
48 memcpy(scratch.c, inp, 16);
49 scratch.u[0] ^= tweak.u[0];
50 scratch.u[1] ^= tweak.u[1];
51 #else
52 scratch.u[0] = ((u64_a1 *)inp)[0] ^ tweak.u[0];
53 scratch.u[1] = ((u64_a1 *)inp)[1] ^ tweak.u[1];
54 #endif
55 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
56 #if defined(STRICT_ALIGNMENT)
57 scratch.u[0] ^= tweak.u[0];
58 scratch.u[1] ^= tweak.u[1];
59 memcpy(out, scratch.c, 16);
60 #else
61 ((u64_a1 *)out)[0] = scratch.u[0] ^= tweak.u[0];
62 ((u64_a1 *)out)[1] = scratch.u[1] ^= tweak.u[1];
63 #endif
64 inp += 16;
65 out += 16;
66 len -= 16;
67
68 if (len == 0)
69 return 0;
70
71 if (IS_LITTLE_ENDIAN) {
72 u8 res;
73 u64 hi, lo;
74 #ifdef BSWAP8
75 hi = BSWAP8(tweak.u[0]);
76 lo = BSWAP8(tweak.u[1]);
77 #else
78 u8 *p = tweak.c;
79
80 hi = (u64)GETU32(p) << 32 | GETU32(p + 4);
81 lo = (u64)GETU32(p + 8) << 32 | GETU32(p + 12);
82 #endif
83 res = (u8)lo & 1;
84 tweak.u[0] = (lo >> 1) | (hi << 63);
85 tweak.u[1] = hi >> 1;
86 if (res)
87 tweak.c[15] ^= 0xe1;
88 #ifdef BSWAP8
89 hi = BSWAP8(tweak.u[0]);
90 lo = BSWAP8(tweak.u[1]);
91 #else
92 p = tweak.c;
93
94 hi = (u64)GETU32(p) << 32 | GETU32(p + 4);
95 lo = (u64)GETU32(p + 8) << 32 | GETU32(p + 12);
96 #endif
97 tweak.u[0] = lo;
98 tweak.u[1] = hi;
99 } else {
100 u8 carry, res;
101 carry = 0;
102 for (i = 0; i < 16; ++i) {
103 res = (tweak.c[i] << 7) & 0x80;
104 tweak.c[i] = ((tweak.c[i] >> 1) + carry) & 0xff;
105 carry = res;
106 }
107 if (res)
108 tweak.c[0] ^= 0xe1;
109 }
110 }
111 if (enc) {
112 for (i = 0; i < len; ++i) {
113 u8 c = inp[i];
114 out[i] = scratch.c[i];
115 scratch.c[i] = c;
116 }
117 scratch.u[0] ^= tweak.u[0];
118 scratch.u[1] ^= tweak.u[1];
119 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
120 scratch.u[0] ^= tweak.u[0];
121 scratch.u[1] ^= tweak.u[1];
122 memcpy(out - 16, scratch.c, 16);
123 } else {
124 union {
125 u64 u[2];
126 u8 c[16];
127 } tweak1;
128
129 if (IS_LITTLE_ENDIAN) {
130 u8 res;
131 u64 hi, lo;
132 #ifdef BSWAP8
133 hi = BSWAP8(tweak.u[0]);
134 lo = BSWAP8(tweak.u[1]);
135 #else
136 u8 *p = tweak.c;
137
138 hi = (u64)GETU32(p) << 32 | GETU32(p + 4);
139 lo = (u64)GETU32(p + 8) << 32 | GETU32(p + 12);
140 #endif
141 res = (u8)lo & 1;
142 tweak1.u[0] = (lo >> 1) | (hi << 63);
143 tweak1.u[1] = hi >> 1;
144 if (res)
145 tweak1.c[15] ^= 0xe1;
146 #ifdef BSWAP8
147 hi = BSWAP8(tweak1.u[0]);
148 lo = BSWAP8(tweak1.u[1]);
149 #else
150 p = tweak1.c;
151
152 hi = (u64)GETU32(p) << 32 | GETU32(p + 4);
153 lo = (u64)GETU32(p + 8) << 32 | GETU32(p + 12);
154 #endif
155 tweak1.u[0] = lo;
156 tweak1.u[1] = hi;
157 } else {
158 u8 carry, res;
159 carry = 0;
160 for (i = 0; i < 16; ++i) {
161 res = (tweak.c[i] << 7) & 0x80;
162 tweak1.c[i] = ((tweak.c[i] >> 1) + carry) & 0xff;
163 carry = res;
164 }
165 if (res)
166 tweak1.c[0] ^= 0xe1;
167 }
168 #if defined(STRICT_ALIGNMENT)
169 memcpy(scratch.c, inp, 16);
170 scratch.u[0] ^= tweak1.u[0];
171 scratch.u[1] ^= tweak1.u[1];
172 #else
173 scratch.u[0] = ((u64_a1 *)inp)[0] ^ tweak1.u[0];
174 scratch.u[1] = ((u64_a1 *)inp)[1] ^ tweak1.u[1];
175 #endif
176 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
177 scratch.u[0] ^= tweak1.u[0];
178 scratch.u[1] ^= tweak1.u[1];
179
180 for (i = 0; i < len; ++i) {
181 u8 c = inp[16 + i];
182 out[16 + i] = scratch.c[i];
183 scratch.c[i] = c;
184 }
185 scratch.u[0] ^= tweak.u[0];
186 scratch.u[1] ^= tweak.u[1];
187 (*ctx->block1) (scratch.c, scratch.c, ctx->key1);
188 #if defined(STRICT_ALIGNMENT)
189 scratch.u[0] ^= tweak.u[0];
190 scratch.u[1] ^= tweak.u[1];
191 memcpy(out, scratch.c, 16);
192 #else
193 ((u64_a1 *)out)[0] = scratch.u[0] ^ tweak.u[0];
194 ((u64_a1 *)out)[1] = scratch.u[1] ^ tweak.u[1];
195 #endif
196 }
197
198 return 0;
199 }
200
