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  1/*
  2 * Shared glue code for 128bit block ciphers
  3 *
  4 * Copyright © 2012-2013 Jussi Kivilinna <jussi.kivilinna@iki.fi>
  5 *
  6 * CBC & ECB parts based on code (crypto/cbc.c,ecb.c) by:
  7 *   Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  8 * CTR part based on code (crypto/ctr.c) by:
  9 *   (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
 10 *
 11 * This program is free software; you can redistribute it and/or modify
 12 * it under the terms of the GNU General Public License as published by
 13 * the Free Software Foundation; either version 2 of the License, or
 14 * (at your option) any later version.
 15 *
 16 * This program is distributed in the hope that it will be useful,
 17 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 18 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 19 * GNU General Public License for more details.
 20 *
 21 * You should have received a copy of the GNU General Public License
 22 * along with this program; if not, write to the Free Software
 23 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
 24 * USA
 25 *
 26 */
 27
 28#include <linux/module.h>
 29#include <crypto/b128ops.h>
 30#include <crypto/lrw.h>
 31#include <crypto/xts.h>
 32#include <asm/crypto/glue_helper.h>
 33#include <crypto/scatterwalk.h>
 34
 35static int __glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
 36				   struct blkcipher_desc *desc,
 37				   struct blkcipher_walk *walk)
 38{
 39	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 40	const unsigned int bsize = 128 / 8;
 41	unsigned int nbytes, i, func_bytes;
 42	bool fpu_enabled = false;
 43	int err;
 44
 45	err = blkcipher_walk_virt(desc, walk);
 46
 47	while ((nbytes = walk->nbytes)) {
 48		u8 *wsrc = walk->src.virt.addr;
 49		u8 *wdst = walk->dst.virt.addr;
 50
 51		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
 52					     desc, fpu_enabled, nbytes);
 53
 54		for (i = 0; i < gctx->num_funcs; i++) {
 55			func_bytes = bsize * gctx->funcs[i].num_blocks;
 56
 57			/* Process multi-block batch */
 58			if (nbytes >= func_bytes) {
 59				do {
 60					gctx->funcs[i].fn_u.ecb(ctx, wdst,
 61								wsrc);
 62
 63					wsrc += func_bytes;
 64					wdst += func_bytes;
 65					nbytes -= func_bytes;
 66				} while (nbytes >= func_bytes);
 67
 68				if (nbytes < bsize)
 69					goto done;
 70			}
 71		}
 72
 73done:
 74		err = blkcipher_walk_done(desc, walk, nbytes);
 75	}
 76
 77	glue_fpu_end(fpu_enabled);
 78	return err;
 79}
 80
 81int glue_ecb_crypt_128bit(const struct common_glue_ctx *gctx,
 82			  struct blkcipher_desc *desc, struct scatterlist *dst,
 83			  struct scatterlist *src, unsigned int nbytes)
 84{
 85	struct blkcipher_walk walk;
 86
 87	blkcipher_walk_init(&walk, dst, src, nbytes);
 88	return __glue_ecb_crypt_128bit(gctx, desc, &walk);
 89}
 90EXPORT_SYMBOL_GPL(glue_ecb_crypt_128bit);
 91
 92static unsigned int __glue_cbc_encrypt_128bit(const common_glue_func_t fn,
 93					      struct blkcipher_desc *desc,
 94					      struct blkcipher_walk *walk)
 95{
 96	void *ctx = crypto_blkcipher_ctx(desc->tfm);
 97	const unsigned int bsize = 128 / 8;
 98	unsigned int nbytes = walk->nbytes;
 99	u128 *src = (u128 *)walk->src.virt.addr;
100	u128 *dst = (u128 *)walk->dst.virt.addr;
101	u128 *iv = (u128 *)walk->iv;
102
103	do {
104		u128_xor(dst, src, iv);
105		fn(ctx, (u8 *)dst, (u8 *)dst);
106		iv = dst;
107
108		src += 1;
109		dst += 1;
110		nbytes -= bsize;
111	} while (nbytes >= bsize);
112
113	*(u128 *)walk->iv = *iv;
114	return nbytes;
115}
116
117int glue_cbc_encrypt_128bit(const common_glue_func_t fn,
118			    struct blkcipher_desc *desc,
119			    struct scatterlist *dst,
120			    struct scatterlist *src, unsigned int nbytes)
121{
122	struct blkcipher_walk walk;
123	int err;
124
125	blkcipher_walk_init(&walk, dst, src, nbytes);
126	err = blkcipher_walk_virt(desc, &walk);
127
128	while ((nbytes = walk.nbytes)) {
129		nbytes = __glue_cbc_encrypt_128bit(fn, desc, &walk);
130		err = blkcipher_walk_done(desc, &walk, nbytes);
131	}
132
133	return err;
134}
135EXPORT_SYMBOL_GPL(glue_cbc_encrypt_128bit);
136
137static unsigned int
138__glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
139			  struct blkcipher_desc *desc,
140			  struct blkcipher_walk *walk)
141{
142	void *ctx = crypto_blkcipher_ctx(desc->tfm);
143	const unsigned int bsize = 128 / 8;
144	unsigned int nbytes = walk->nbytes;
145	u128 *src = (u128 *)walk->src.virt.addr;
146	u128 *dst = (u128 *)walk->dst.virt.addr;
147	u128 last_iv;
148	unsigned int num_blocks, func_bytes;
149	unsigned int i;
150
151	/* Start of the last block. */
152	src += nbytes / bsize - 1;
153	dst += nbytes / bsize - 1;
154
155	last_iv = *src;
156
157	for (i = 0; i < gctx->num_funcs; i++) {
158		num_blocks = gctx->funcs[i].num_blocks;
159		func_bytes = bsize * num_blocks;
160
161		/* Process multi-block batch */
162		if (nbytes >= func_bytes) {
163			do {
164				nbytes -= func_bytes - bsize;
165				src -= num_blocks - 1;
166				dst -= num_blocks - 1;
167
168				gctx->funcs[i].fn_u.cbc(ctx, dst, src);
169
170				nbytes -= bsize;
171				if (nbytes < bsize)
172					goto done;
173
174				u128_xor(dst, dst, src - 1);
175				src -= 1;
176				dst -= 1;
177			} while (nbytes >= func_bytes);
178
179			if (nbytes < bsize)
180				goto done;
181		}
182	}
183
184done:
185	u128_xor(dst, dst, (u128 *)walk->iv);
186	*(u128 *)walk->iv = last_iv;
187
188	return nbytes;
189}
190
191int glue_cbc_decrypt_128bit(const struct common_glue_ctx *gctx,
192			    struct blkcipher_desc *desc,
193			    struct scatterlist *dst,
194			    struct scatterlist *src, unsigned int nbytes)
195{
196	const unsigned int bsize = 128 / 8;
197	bool fpu_enabled = false;
198	struct blkcipher_walk walk;
199	int err;
200
201	blkcipher_walk_init(&walk, dst, src, nbytes);
202	err = blkcipher_walk_virt(desc, &walk);
203
204	while ((nbytes = walk.nbytes)) {
205		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
206					     desc, fpu_enabled, nbytes);
207		nbytes = __glue_cbc_decrypt_128bit(gctx, desc, &walk);
208		err = blkcipher_walk_done(desc, &walk, nbytes);
209	}
210
211	glue_fpu_end(fpu_enabled);
212	return err;
213}
214EXPORT_SYMBOL_GPL(glue_cbc_decrypt_128bit);
215
216static void glue_ctr_crypt_final_128bit(const common_glue_ctr_func_t fn_ctr,
217					struct blkcipher_desc *desc,
218					struct blkcipher_walk *walk)
219{
220	void *ctx = crypto_blkcipher_ctx(desc->tfm);
221	u8 *src = (u8 *)walk->src.virt.addr;
222	u8 *dst = (u8 *)walk->dst.virt.addr;
223	unsigned int nbytes = walk->nbytes;
224	le128 ctrblk;
225	u128 tmp;
226
227	be128_to_le128(&ctrblk, (be128 *)walk->iv);
228
229	memcpy(&tmp, src, nbytes);
230	fn_ctr(ctx, &tmp, &tmp, &ctrblk);
231	memcpy(dst, &tmp, nbytes);
232
233	le128_to_be128((be128 *)walk->iv, &ctrblk);
234}
235EXPORT_SYMBOL_GPL(glue_ctr_crypt_final_128bit);
236
237static unsigned int __glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
238					    struct blkcipher_desc *desc,
239					    struct blkcipher_walk *walk)
240{
241	const unsigned int bsize = 128 / 8;
242	void *ctx = crypto_blkcipher_ctx(desc->tfm);
243	unsigned int nbytes = walk->nbytes;
244	u128 *src = (u128 *)walk->src.virt.addr;
245	u128 *dst = (u128 *)walk->dst.virt.addr;
246	le128 ctrblk;
247	unsigned int num_blocks, func_bytes;
248	unsigned int i;
249
250	be128_to_le128(&ctrblk, (be128 *)walk->iv);
251
252	/* Process multi-block batch */
253	for (i = 0; i < gctx->num_funcs; i++) {
254		num_blocks = gctx->funcs[i].num_blocks;
255		func_bytes = bsize * num_blocks;
256
257		if (nbytes >= func_bytes) {
258			do {
259				gctx->funcs[i].fn_u.ctr(ctx, dst, src, &ctrblk);
260
261				src += num_blocks;
262				dst += num_blocks;
263				nbytes -= func_bytes;
264			} while (nbytes >= func_bytes);
265
266			if (nbytes < bsize)
267				goto done;
268		}
269	}
270
271done:
272	le128_to_be128((be128 *)walk->iv, &ctrblk);
273	return nbytes;
274}
275
276int glue_ctr_crypt_128bit(const struct common_glue_ctx *gctx,
277			  struct blkcipher_desc *desc, struct scatterlist *dst,
278			  struct scatterlist *src, unsigned int nbytes)
279{
280	const unsigned int bsize = 128 / 8;
281	bool fpu_enabled = false;
282	struct blkcipher_walk walk;
283	int err;
284
285	blkcipher_walk_init(&walk, dst, src, nbytes);
286	err = blkcipher_walk_virt_block(desc, &walk, bsize);
287
288	while ((nbytes = walk.nbytes) >= bsize) {
289		fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
290					     desc, fpu_enabled, nbytes);
291		nbytes = __glue_ctr_crypt_128bit(gctx, desc, &walk);
292		err = blkcipher_walk_done(desc, &walk, nbytes);
293	}
294
295	glue_fpu_end(fpu_enabled);
296
297	if (walk.nbytes) {
298		glue_ctr_crypt_final_128bit(
299			gctx->funcs[gctx->num_funcs - 1].fn_u.ctr, desc, &walk);
300		err = blkcipher_walk_done(desc, &walk, 0);
301	}
302
303	return err;
304}
305EXPORT_SYMBOL_GPL(glue_ctr_crypt_128bit);
306
307static unsigned int __glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
308					    void *ctx,
309					    struct blkcipher_desc *desc,
310					    struct blkcipher_walk *walk)
311{
312	const unsigned int bsize = 128 / 8;
313	unsigned int nbytes = walk->nbytes;
314	u128 *src = (u128 *)walk->src.virt.addr;
315	u128 *dst = (u128 *)walk->dst.virt.addr;
316	unsigned int num_blocks, func_bytes;
317	unsigned int i;
318
319	/* Process multi-block batch */
320	for (i = 0; i < gctx->num_funcs; i++) {
321		num_blocks = gctx->funcs[i].num_blocks;
322		func_bytes = bsize * num_blocks;
323
324		if (nbytes >= func_bytes) {
325			do {
326				gctx->funcs[i].fn_u.xts(ctx, dst, src,
327							(le128 *)walk->iv);
328
329				src += num_blocks;
330				dst += num_blocks;
331				nbytes -= func_bytes;
332			} while (nbytes >= func_bytes);
333
334			if (nbytes < bsize)
335				goto done;
336		}
337	}
338
339done:
340	return nbytes;
341}
342
343/* for implementations implementing faster XTS IV generator */
344int glue_xts_crypt_128bit(const struct common_glue_ctx *gctx,
345			  struct blkcipher_desc *desc, struct scatterlist *dst,
346			  struct scatterlist *src, unsigned int nbytes,
347			  void (*tweak_fn)(void *ctx, u8 *dst, const u8 *src),
348			  void *tweak_ctx, void *crypt_ctx)
349{
350	const unsigned int bsize = 128 / 8;
351	bool fpu_enabled = false;
352	struct blkcipher_walk walk;
353	int err;
354
355	blkcipher_walk_init(&walk, dst, src, nbytes);
356
357	err = blkcipher_walk_virt(desc, &walk);
358	nbytes = walk.nbytes;
359	if (!nbytes)
360		return err;
361
362	/* set minimum length to bsize, for tweak_fn */
363	fpu_enabled = glue_fpu_begin(bsize, gctx->fpu_blocks_limit,
364				     desc, fpu_enabled,
365				     nbytes < bsize ? bsize : nbytes);
366
367	/* calculate first value of T */
368	tweak_fn(tweak_ctx, walk.iv, walk.iv);
369
370	while (nbytes) {
371		nbytes = __glue_xts_crypt_128bit(gctx, crypt_ctx, desc, &walk);
372
373		err = blkcipher_walk_done(desc, &walk, nbytes);
374		nbytes = walk.nbytes;
375	}
376
377	glue_fpu_end(fpu_enabled);
378
379	return err;
380}
381EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit);
382
383void glue_xts_crypt_128bit_one(void *ctx, u128 *dst, const u128 *src, le128 *iv,
384			       common_glue_func_t fn)
385{
386	le128 ivblk = *iv;
387
388	/* generate next IV */
389	le128_gf128mul_x_ble(iv, &ivblk);
390
391	/* CC <- T xor C */
392	u128_xor(dst, src, (u128 *)&ivblk);
393
394	/* PP <- D(Key2,CC) */
395	fn(ctx, (u8 *)dst, (u8 *)dst);
396
397	/* P <- T xor PP */
398	u128_xor(dst, dst, (u128 *)&ivblk);
399}
400EXPORT_SYMBOL_GPL(glue_xts_crypt_128bit_one);
401
402MODULE_LICENSE("GPL");