summaryrefslogtreecommitdiff
path: root/arch/x86/crypto/glue_helper.c
blob: 9015514453875851508bb6e11a5f157ecf0d6229 (plain) (blame)
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
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 * Shared glue code for 128bit block ciphers
 *
 * Copyright © 2012-2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
 *
 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 * CTR part based on code (crypto/ctr.c) by:
 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 */

#include <linux/module.h>
#include <crypto/b128ops.h>
#include <crypto/gf128mul.h>
#include <crypto/internal/skcipher.h>
#include <crypto/xts.h>
#include <asm/crypto/glue_helper.h>

int glue_ecb_req_128bit(const struct common_glue_ctx *gctx,
			struct skcipher_request *req)
{
	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
	const unsigned int bsize = 128 / 8;
	struct skcipher_walk walk;
	bool fpu_enabled = false;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

	while ((nbytes = walk.nbytes)) {
		const u8 *src = walk.src.virt.addr;
		u8 *dst = walk.dst.virt.addr;
		unsigned int func_bytes;
		unsigned int i;

		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
					     &walk, fpu_enabled, nbytes);
		for (i = 0; i < gctx->num_funcs; i++) {
			func_bytes = bsize * gctx->funcs[i].num_blocks;

			if (nbytes < func_bytes)
				continue;

			/* Process multi-block batch */
			do {
				gctx->funcs[i].fn_u.ecb(ctx, dst, src);
				src += func_bytes;
				dst += func_bytes;
				nbytes -= func_bytes;
			} while (nbytes >= func_bytes);

			if (nbytes < bsize)
				break;
		}
		err = skcipher_walk_done(&walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);
	return err;
}
EXPORT_SYMBOL_GPL(glue_ecb_req_128bit);

int glue_cbc_encrypt_req_128bit(const common_glue_func_t fn,
				struct skcipher_request *req)
{
	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
	const unsigned int bsize = 128 / 8;
	struct skcipher_walk walk;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

	while ((nbytes = walk.nbytes)) {
		const u128 *src = (u128 *)walk.src.virt.addr;
		u128 *dst = (u128 *)walk.dst.virt.addr;
		u128 *iv = (u128 *)walk.iv;

		do {
			u128_xor(dst, src, iv);
			fn(ctx, (u8 *)dst, (u8 *)dst);
			iv = dst;
			src++;
			dst++;
			nbytes -= bsize;
		} while (nbytes >= bsize);

		*(u128 *)walk.iv = *iv;
		err = skcipher_walk_done(&walk, nbytes);
	}
	return err;
}
EXPORT_SYMBOL_GPL(glue_cbc_encrypt_req_128bit);

int glue_cbc_decrypt_req_128bit(const struct common_glue_ctx *gctx,
				struct skcipher_request *req)
{
	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
	const unsigned int bsize = 128 / 8;
	struct skcipher_walk walk;
	bool fpu_enabled = false;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

	while ((nbytes = walk.nbytes)) {
		const u128 *src = walk.src.virt.addr;
		u128 *dst = walk.dst.virt.addr;
		unsigned int func_bytes, num_blocks;
		unsigned int i;
		u128 last_iv;

		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
					     &walk, fpu_enabled, nbytes);
		/* Start of the last block. */
		src += nbytes / bsize - 1;
		dst += nbytes / bsize - 1;

		last_iv = *src;

		for (i = 0; i < gctx->num_funcs; i++) {
			num_blocks = gctx->funcs[i].num_blocks;
			func_bytes = bsize * num_blocks;

			if (nbytes < func_bytes)
				continue;

			/* Process multi-block batch */
			do {
				src -= num_blocks - 1;
				dst -= num_blocks - 1;

				gctx->funcs[i].fn_u.cbc(ctx, dst, src);

				nbytes -= func_bytes;
				if (nbytes < bsize)
					goto done;

				u128_xor(dst, dst, --src);
				dst--;
			} while (nbytes >= func_bytes);
		}
done:
		u128_xor(dst, dst, (u128 *)walk.iv);
		*(u128 *)walk.iv = last_iv;
		err = skcipher_walk_done(&walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);
	return err;
}
EXPORT_SYMBOL_GPL(glue_cbc_decrypt_req_128bit);

int glue_ctr_req_128bit(const struct common_glue_ctx *gctx,
			struct skcipher_request *req)
{
	void *ctx = crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
	const unsigned int bsize = 128 / 8;
	struct skcipher_walk walk;
	bool fpu_enabled = false;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);

	while ((nbytes = walk.nbytes) >= bsize) {
		const u128 *src = walk.src.virt.addr;
		u128 *dst = walk.dst.virt.addr;
		unsigned int func_bytes, num_blocks;
		unsigned int i;
		le128 ctrblk;

		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
					     &walk, fpu_enabled, nbytes);

		be128_to_le128(&ctrblk, (be128 *)walk.iv);

		for (i = 0; i < gctx->num_funcs; i++) {
			num_blocks = gctx->funcs[i].num_blocks;
			func_bytes = bsize * num_blocks;

			if (nbytes < func_bytes)
				continue;

			/* Process multi-block batch */
			do {
				gctx->funcs[i].fn_u.ctr(ctx, dst, src, &ctrblk);
				src += num_blocks;
				dst += num_blocks;
				nbytes -= func_bytes;
			} while (nbytes >= func_bytes);

			if (nbytes < bsize)
				break;
		}

		le128_to_be128((be128 *)walk.iv, &ctrblk);
		err = skcipher_walk_done(&walk, nbytes);
	}

	glue_fpu_end(fpu_enabled);

	if (nbytes) {
		le128 ctrblk;
		u128 tmp;

		be128_to_le128(&ctrblk, (be128 *)walk.iv);
		memcpy(&tmp, walk.src.virt.addr, nbytes);
		gctx->funcs[gctx->num_funcs - 1].fn_u.ctr(ctx, &tmp, &tmp,
							  &ctrblk);
		memcpy(walk.dst.virt.addr, &tmp, nbytes);
		le128_to_be128((be128 *)walk.iv, &ctrblk);

		err = skcipher_walk_done(&walk, 0);
	}

	return err;
}
EXPORT_SYMBOL_GPL(glue_ctr_req_128bit);

static unsigned int __glue_xts_req_128bit(const struct common_glue_ctx *gctx,
					  void *ctx,
					  struct skcipher_walk *walk)
{
	const unsigned int bsize = 128 / 8;
	unsigned int nbytes = walk->nbytes;
	u128 *src = walk->src.virt.addr;
	u128 *dst = walk->dst.virt.addr;
	unsigned int num_blocks, func_bytes;
	unsigned int i;

	/* Process multi-block batch */
	for (i = 0; i < gctx->num_funcs; i++) {
		num_blocks = gctx->funcs[i].num_blocks;
		func_bytes = bsize * num_blocks;

		if (nbytes >= func_bytes) {
			do {
				gctx->funcs[i].fn_u.xts(ctx, dst, src,
							walk->iv);

				src += num_blocks;
				dst += num_blocks;
				nbytes -= func_bytes;
			} while (nbytes >= func_bytes);

			if (nbytes < bsize)
				goto done;
		}
	}

done:
	return nbytes;
}

int glue_xts_req_128bit(const struct common_glue_ctx *gctx,
			struct skcipher_request *req,
			common_glue_func_t tweak_fn, void *tweak_ctx,
			void *crypt_ctx)
{
	const unsigned int bsize = 128 / 8;
	struct skcipher_walk walk;
	bool fpu_enabled = false;
	unsigned int nbytes;
	int err;

	err = skcipher_walk_virt(&walk, req, false);
	nbytes = walk.nbytes;
	if (!nbytes)
		return err;

	/* set minimum length to bsize, for tweak_fn */
	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
				     &walk, fpu_enabled,
				     nbytes < bsize ? bsize : nbytes);

	/* calculate first value of T */
	tweak_fn(tweak_ctx, walk.iv, walk.iv);

	while (nbytes) {
		nbytes = __glue_xts_req_128bit(gctx, crypt_ctx, &walk);

		err = skcipher_walk_done(&walk, nbytes);
		nbytes = walk.nbytes;
	}

	glue_fpu_end(fpu_enabled);

	return err;
}
EXPORT_SYMBOL_GPL(glue_xts_req_128bit);

void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
			       common_glue_func_t fn)
{
	le128 ivblk = *iv;

	/* generate next IV */
	gf128mul_x_ble(iv, &ivblk);

	/* CC <- T xor C */
	u128_xor(dst, src, (u128 *)&ivblk);

	/* PP <- D(Key2,CC) */
	fn(ctx, (u8 *)dst, (u8 *)dst);

	/* P <- T xor PP */
	u128_xor(dst, dst, (u128 *)&ivblk);
}
EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit_one);

MODULE_LICENSE("GPL");