1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2015-2018 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved.
*
* This is an implementation of the ChaCha20Poly1305 AEAD construction.
*
* Information: https://tools.ietf.org/html/rfc8439
*/
#include <zinc/chacha20poly1305.h>
#include <zinc/chacha20.h>
#include <zinc/poly1305.h>
#include <asm/unaligned.h>
#include <linux/kernel.h>
#include <crypto/scatterwalk.h>
static const u8 pad0[16] = { 0 };
static struct crypto_alg chacha20_alg = {
.cra_blocksize = 1,
.cra_alignmask = sizeof(u32) - 1
};
static struct crypto_blkcipher chacha20_cipher = {
.base = {
.__crt_alg = &chacha20_alg
}
};
static struct blkcipher_desc chacha20_desc = {
.tfm = &chacha20_cipher
};
static inline void
__chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len, const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN],
simd_context_t simd_context)
{
struct poly1305_ctx poly1305_state;
struct chacha20_ctx chacha20_state;
union {
u8 block0[POLY1305_KEY_SIZE];
__le64 lens[2];
} b = { { 0 } };
chacha20_init(&chacha20_state, key, nonce);
chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
simd_context);
poly1305_init(&poly1305_state, b.block0, simd_context);
poly1305_update(&poly1305_state, ad, ad_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
simd_context);
chacha20(&chacha20_state, dst, src, src_len, simd_context);
poly1305_update(&poly1305_state, dst, src_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - src_len) & 0xf,
simd_context);
b.lens[0] = cpu_to_le64(ad_len);
b.lens[1] = cpu_to_le64(src_len);
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
simd_context);
poly1305_final(&poly1305_state, dst + src_len, simd_context);
memzero_explicit(&chacha20_state, sizeof(chacha20_state));
memzero_explicit(&b, sizeof(b));
}
void chacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN])
{
simd_context_t simd_context;
simd_context = simd_get();
__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len, nonce, key,
simd_context);
simd_put(simd_context);
}
EXPORT_SYMBOL(chacha20poly1305_encrypt);
bool chacha20poly1305_encrypt_sg(struct scatterlist *dst,
struct scatterlist *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN],
simd_context_t simd_context)
{
struct poly1305_ctx poly1305_state;
struct chacha20_ctx chacha20_state;
int ret = 0;
struct blkcipher_walk walk;
union {
u8 block0[POLY1305_KEY_SIZE];
u8 mac[POLY1305_MAC_SIZE];
__le64 lens[2];
} b = { { 0 } };
chacha20_init(&chacha20_state, key, nonce);
chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
simd_context);
poly1305_init(&poly1305_state, b.block0, simd_context);
poly1305_update(&poly1305_state, ad, ad_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
simd_context);
if (likely(src_len)) {
blkcipher_walk_init(&walk, dst, src, src_len);
ret = blkcipher_walk_virt_block(&chacha20_desc, &walk,
CHACHA20_BLOCK_SIZE);
while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
size_t chunk_len =
rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE);
chacha20(&chacha20_state, walk.dst.virt.addr,
walk.src.virt.addr, chunk_len, simd_context);
poly1305_update(&poly1305_state, walk.dst.virt.addr,
chunk_len, simd_context);
ret = blkcipher_walk_done(&chacha20_desc, &walk,
walk.nbytes % CHACHA20_BLOCK_SIZE);
}
if (walk.nbytes) {
chacha20(&chacha20_state, walk.dst.virt.addr,
walk.src.virt.addr, walk.nbytes, simd_context);
poly1305_update(&poly1305_state, walk.dst.virt.addr,
walk.nbytes, simd_context);
ret = blkcipher_walk_done(&chacha20_desc, &walk, 0);
}
}
if (unlikely(ret))
goto err;
poly1305_update(&poly1305_state, pad0, (0x10 - src_len) & 0xf,
simd_context);
b.lens[0] = cpu_to_le64(ad_len);
b.lens[1] = cpu_to_le64(src_len);
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
simd_context);
poly1305_final(&poly1305_state, b.mac, simd_context);
scatterwalk_map_and_copy(b.mac, dst, src_len, sizeof(b.mac), 1);
err:
memzero_explicit(&chacha20_state, sizeof(chacha20_state));
memzero_explicit(&b, sizeof(b));
return !ret;
}
EXPORT_SYMBOL(chacha20poly1305_encrypt_sg);
static inline bool
__chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len, const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN],
simd_context_t simd_context)
{
struct poly1305_ctx poly1305_state;
struct chacha20_ctx chacha20_state;
int ret;
size_t dst_len;
union {
u8 block0[POLY1305_KEY_SIZE];
u8 mac[POLY1305_MAC_SIZE];
__le64 lens[2];
} b = { { 0 } };
if (unlikely(src_len < POLY1305_MAC_SIZE))
return false;
chacha20_init(&chacha20_state, key, nonce);
chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
simd_context);
poly1305_init(&poly1305_state, b.block0, simd_context);
poly1305_update(&poly1305_state, ad, ad_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
simd_context);
dst_len = src_len - POLY1305_MAC_SIZE;
poly1305_update(&poly1305_state, src, dst_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - dst_len) & 0xf,
simd_context);
b.lens[0] = cpu_to_le64(ad_len);
b.lens[1] = cpu_to_le64(dst_len);
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
simd_context);
poly1305_final(&poly1305_state, b.mac, simd_context);
ret = crypto_memneq(b.mac, src + dst_len, POLY1305_MAC_SIZE);
if (likely(!ret))
chacha20(&chacha20_state, dst, src, dst_len, simd_context);
memzero_explicit(&chacha20_state, sizeof(chacha20_state));
memzero_explicit(&b, sizeof(b));
return !ret;
}
bool chacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN])
{
simd_context_t simd_context, ret;
simd_context = simd_get();
ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len, nonce,
key, simd_context);
simd_put(simd_context);
return ret;
}
EXPORT_SYMBOL(chacha20poly1305_decrypt);
bool chacha20poly1305_decrypt_sg(struct scatterlist *dst,
struct scatterlist *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u64 nonce,
const u8 key[CHACHA20POLY1305_KEYLEN],
simd_context_t simd_context)
{
struct poly1305_ctx poly1305_state;
struct chacha20_ctx chacha20_state;
struct blkcipher_walk walk;
int ret = 0;
size_t dst_len;
union {
u8 block0[POLY1305_KEY_SIZE];
struct {
u8 read_mac[POLY1305_MAC_SIZE];
u8 computed_mac[POLY1305_MAC_SIZE];
};
__le64 lens[2];
} b = { { 0 } };
if (unlikely(src_len < POLY1305_MAC_SIZE))
return false;
chacha20_init(&chacha20_state, key, nonce);
chacha20(&chacha20_state, b.block0, b.block0, sizeof(b.block0),
simd_context);
poly1305_init(&poly1305_state, b.block0, simd_context);
poly1305_update(&poly1305_state, ad, ad_len, simd_context);
poly1305_update(&poly1305_state, pad0, (0x10 - ad_len) & 0xf,
simd_context);
dst_len = src_len - POLY1305_MAC_SIZE;
if (likely(dst_len)) {
blkcipher_walk_init(&walk, dst, src, dst_len);
ret = blkcipher_walk_virt_block(&chacha20_desc, &walk,
CHACHA20_BLOCK_SIZE);
while (walk.nbytes >= CHACHA20_BLOCK_SIZE) {
size_t chunk_len =
rounddown(walk.nbytes, CHACHA20_BLOCK_SIZE);
poly1305_update(&poly1305_state, walk.src.virt.addr,
chunk_len, simd_context);
chacha20(&chacha20_state, walk.dst.virt.addr,
walk.src.virt.addr, chunk_len, simd_context);
ret = blkcipher_walk_done(&chacha20_desc, &walk,
walk.nbytes % CHACHA20_BLOCK_SIZE);
}
if (walk.nbytes) {
poly1305_update(&poly1305_state, walk.src.virt.addr,
walk.nbytes, simd_context);
chacha20(&chacha20_state, walk.dst.virt.addr,
walk.src.virt.addr, walk.nbytes, simd_context);
ret = blkcipher_walk_done(&chacha20_desc, &walk, 0);
}
}
if (unlikely(ret))
goto err;
poly1305_update(&poly1305_state, pad0, (0x10 - dst_len) & 0xf,
simd_context);
b.lens[0] = cpu_to_le64(ad_len);
b.lens[1] = cpu_to_le64(dst_len);
poly1305_update(&poly1305_state, (u8 *)b.lens, sizeof(b.lens),
simd_context);
poly1305_final(&poly1305_state, b.computed_mac, simd_context);
scatterwalk_map_and_copy(b.read_mac, src, dst_len, POLY1305_MAC_SIZE, 0);
ret = crypto_memneq(b.read_mac, b.computed_mac, POLY1305_MAC_SIZE);
err:
memzero_explicit(&chacha20_state, sizeof(chacha20_state));
memzero_explicit(&b, sizeof(b));
return !ret;
}
EXPORT_SYMBOL(chacha20poly1305_decrypt_sg);
void xchacha20poly1305_encrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u8 nonce[XCHACHA20POLY1305_NONCELEN],
const u8 key[CHACHA20POLY1305_KEYLEN])
{
simd_context_t simd_context = simd_get();
u8 derived_key[CHACHA20POLY1305_KEYLEN] __aligned(16);
hchacha20(derived_key, nonce, key, simd_context);
__chacha20poly1305_encrypt(dst, src, src_len, ad, ad_len,
get_unaligned_le64(nonce + 16),
derived_key, simd_context);
memzero_explicit(derived_key, CHACHA20POLY1305_KEYLEN);
simd_put(simd_context);
}
EXPORT_SYMBOL(xchacha20poly1305_encrypt);
bool xchacha20poly1305_decrypt(u8 *dst, const u8 *src, const size_t src_len,
const u8 *ad, const size_t ad_len,
const u8 nonce[XCHACHA20POLY1305_NONCELEN],
const u8 key[CHACHA20POLY1305_KEYLEN])
{
bool ret, simd_context = simd_get();
u8 derived_key[CHACHA20POLY1305_KEYLEN] __aligned(16);
hchacha20(derived_key, nonce, key, simd_context);
ret = __chacha20poly1305_decrypt(dst, src, src_len, ad, ad_len,
get_unaligned_le64(nonce + 16),
derived_key, simd_context);
memzero_explicit(derived_key, CHACHA20POLY1305_KEYLEN);
simd_put(simd_context);
return ret;
}
EXPORT_SYMBOL(xchacha20poly1305_decrypt);
#include "selftest/chacha20poly1305.h"
|
