aboutsummaryrefslogtreecommitdiff
path: root/crypto/ablkcipher.c
blob: d676fc59521a0bceb1064ff1bdab0acdc7ccd6f6 (plain)
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
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
/*
 * Asynchronous block chaining cipher operations.
 *
 * This is the asynchronous version of blkcipher.c indicating completion
 * via a callback.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/internal/skcipher.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>

#include <crypto/scatterwalk.h>

#include "internal.h"

struct ablkcipher_buffer {
	struct list_head	entry;
	struct scatter_walk	dst;
	unsigned int		len;
	void			*data;
};

enum {
	ABLKCIPHER_WALK_SLOW = 1 << 0,
};

static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
{
	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
}

void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
	struct ablkcipher_buffer *p, *tmp;

	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
		ablkcipher_buffer_write(p);
		list_del(&p->entry);
		kfree(p);
	}
}
EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);

static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
					  struct ablkcipher_buffer *p)
{
	p->dst = walk->out;
	list_add_tail(&p->entry, &walk->buffers);
}

/* Get a spot of the specified length that does not straddle a page.
 * The caller needs to ensure that there is enough space for this operation.
 */
static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);

	return max(start, end_page);
}

static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
						unsigned int bsize)
{
	unsigned int n = bsize;

	for (;;) {
		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);

		if (len_this_page > n)
			len_this_page = n;
		scatterwalk_advance(&walk->out, n);
		if (n == len_this_page)
			break;
		n -= len_this_page;
		scatterwalk_start(&walk->out, sg_next(walk->out.sg));
	}

	return bsize;
}

static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
						unsigned int n)
{
	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);

	return n;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
				struct ablkcipher_walk *walk);

int ablkcipher_walk_done(struct ablkcipher_request *req,
			 struct ablkcipher_walk *walk, int err)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int nbytes = 0;

	if (likely(err >= 0)) {
		unsigned int n = walk->nbytes - err;

		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
			n = ablkcipher_done_fast(walk, n);
		else if (WARN_ON(err)) {
			err = -EINVAL;
			goto err;
		} else
			n = ablkcipher_done_slow(walk, n);

		nbytes = walk->total - n;
		err = 0;
	}

	scatterwalk_done(&walk->in, 0, nbytes);
	scatterwalk_done(&walk->out, 1, nbytes);

err:
	walk->total = nbytes;
	walk->nbytes = nbytes;

	if (nbytes) {
		crypto_yield(req->base.flags);
		return ablkcipher_walk_next(req, walk);
	}

	if (walk->iv != req->info)
		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
	kfree(walk->iv_buffer);

	return err;
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_done);

static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
				       struct ablkcipher_walk *walk,
				       unsigned int bsize,
				       unsigned int alignmask,
				       void **src_p, void **dst_p)
{
	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
	struct ablkcipher_buffer *p;
	void *src, *dst, *base;
	unsigned int n;

	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
	n += (aligned_bsize * 3 - (alignmask + 1) +
	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));

	p = kmalloc(n, GFP_ATOMIC);
	if (!p)
		return ablkcipher_walk_done(req, walk, -ENOMEM);

	base = p + 1;

	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
	src = dst = ablkcipher_get_spot(dst, bsize);

	p->len = bsize;
	p->data = dst;

	scatterwalk_copychunks(src, &walk->in, bsize, 0);

	ablkcipher_queue_write(walk, p);

	walk->nbytes = bsize;
	walk->flags |= ABLKCIPHER_WALK_SLOW;

	*src_p = src;
	*dst_p = dst;

	return 0;
}

static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
				     struct crypto_tfm *tfm,
				     unsigned int alignmask)
{
	unsigned bs = walk->blocksize;
	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
			    (alignmask + 1);
	u8 *iv;

	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
	if (!walk->iv_buffer)
		return -ENOMEM;

	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	iv = ablkcipher_get_spot(iv, ivsize);

	walk->iv = memcpy(iv, walk->iv, ivsize);
	return 0;
}

static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
				       struct ablkcipher_walk *walk)
{
	walk->src.page = scatterwalk_page(&walk->in);
	walk->src.offset = offset_in_page(walk->in.offset);
	walk->dst.page = scatterwalk_page(&walk->out);
	walk->dst.offset = offset_in_page(walk->out.offset);

	return 0;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
				struct ablkcipher_walk *walk)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int alignmask, bsize, n;
	void *src, *dst;
	int err;

	alignmask = crypto_tfm_alg_alignmask(tfm);
	n = walk->total;
	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return ablkcipher_walk_done(req, walk, -EINVAL);
	}

	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
	src = dst = NULL;

	bsize = min(walk->blocksize, n);
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (n < bsize ||
	    !scatterwalk_aligned(&walk->in, alignmask) ||
	    !scatterwalk_aligned(&walk->out, alignmask)) {
		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
					   &src, &dst);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;

	return ablkcipher_next_fast(req, walk);

set_phys_lowmem:
	if (err >= 0) {
		walk->src.page = virt_to_page(src);
		walk->dst.page = virt_to_page(dst);
		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
	}

	return err;
}

static int ablkcipher_walk_first(struct ablkcipher_request *req,
				 struct ablkcipher_walk *walk)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int alignmask;

	alignmask = crypto_tfm_alg_alignmask(tfm);
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	walk->iv = req->info;
	walk->nbytes = walk->total;
	if (unlikely(!walk->total))
		return 0;

	walk->iv_buffer = NULL;
	if (unlikely(((unsigned long)walk->iv & alignmask))) {
		int err = ablkcipher_copy_iv(walk, tfm, alignmask);

		if (err)
			return err;
	}

	scatterwalk_start(&walk->in, walk->in.sg);
	scatterwalk_start(&walk->out, walk->out.sg);

	return ablkcipher_walk_next(req, walk);
}

int ablkcipher_walk_phys(struct ablkcipher_request *req,
			 struct ablkcipher_walk *walk)
{
	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
	return ablkcipher_walk_first(req, walk);
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);

static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
			    unsigned int keylen)
{
	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = cipher->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
}

static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
		  unsigned int keylen)
{
	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);

	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	if ((unsigned long)key & alignmask)
		return setkey_unaligned(tfm, key, keylen);

	return cipher->setkey(tfm, key, keylen);
}

static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
					      u32 mask)
{
	return alg->cra_ctxsize;
}

static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
				      u32 mask)
{
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

	if (alg->ivsize > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	crt->base = __crypto_ablkcipher_cast(tfm);
	crt->ivsize = alg->ivsize;

	return 0;
}

#ifdef CONFIG_NET
static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_blkcipher rblkcipher;

	strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
		sizeof(rblkcipher.geniv));

	rblkcipher.blocksize = alg->cra_blocksize;
	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;

	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}
#else
static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

	seq_printf(m, "type         : ablkcipher\n");
	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
					     "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
}

const struct crypto_type crypto_ablkcipher_type = {
	.ctxsize = crypto_ablkcipher_ctxsize,
	.init = crypto_init_ablkcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_ablkcipher_show,
#endif
	.report = crypto_ablkcipher_report,
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);

static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
				      u32 mask)
{
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

	if (alg->ivsize > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
		      alg->setkey : setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	crt->base = __crypto_ablkcipher_cast(tfm);
	crt->ivsize = alg->ivsize;

	return 0;
}

#ifdef CONFIG_NET
static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_blkcipher rblkcipher;

	strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
		sizeof(rblkcipher.geniv));

	rblkcipher.blocksize = alg->cra_blocksize;
	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;

	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
		goto nla_put_failure;
	return 0;

nla_put_failure:
	return -EMSGSIZE;
}
#else
static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

	seq_printf(m, "type         : givcipher\n");
	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
					     "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
}

const struct crypto_type crypto_givcipher_type = {
	.ctxsize = crypto_ablkcipher_ctxsize,
	.init = crypto_init_givcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_givcipher_show,
#endif
	.report = crypto_givcipher_report,
};
EXPORT_SYMBOL_GPL(crypto_givcipher_type);