]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/blame - crypto/blkcipher.c
UBUNTU: SAUCE: media: uvcvideo: Support realtek's UVC 1.5 device
[mirror_ubuntu-artful-kernel.git] / crypto / blkcipher.c
CommitLineData
5cde0af2
HX
1/*
2 * Block chaining cipher operations.
d8c34b94 3 *
5cde0af2
HX
4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
5 * multiple page boundaries by using temporary blocks. In user context,
6 * the kernel is given a chance to schedule us once per page.
7 *
8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
d8c34b94 12 * Software Foundation; either version 2 of the License, or (at your option)
5cde0af2
HX
13 * any later version.
14 *
15 */
16
d1a2fd50 17#include <crypto/aead.h>
ecfc4329 18#include <crypto/internal/skcipher.h>
42c271c6 19#include <crypto/scatterwalk.h>
5cde0af2 20#include <linux/errno.h>
fb469840 21#include <linux/hardirq.h>
5cde0af2 22#include <linux/kernel.h>
5cde0af2 23#include <linux/module.h>
5cde0af2
HX
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/string.h>
50496a1f 27#include <linux/cryptouser.h>
d8c34b94 28#include <linux/compiler.h>
50496a1f 29#include <net/netlink.h>
5cde0af2
HX
30
31#include "internal.h"
5cde0af2
HX
32
33enum {
34 BLKCIPHER_WALK_PHYS = 1 << 0,
35 BLKCIPHER_WALK_SLOW = 1 << 1,
36 BLKCIPHER_WALK_COPY = 1 << 2,
37 BLKCIPHER_WALK_DIFF = 1 << 3,
38};
39
40static int blkcipher_walk_next(struct blkcipher_desc *desc,
41 struct blkcipher_walk *walk);
42static int blkcipher_walk_first(struct blkcipher_desc *desc,
43 struct blkcipher_walk *walk);
44
45static inline void blkcipher_map_src(struct blkcipher_walk *walk)
46{
f0dfc0b0 47 walk->src.virt.addr = scatterwalk_map(&walk->in);
5cde0af2
HX
48}
49
50static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
51{
f0dfc0b0 52 walk->dst.virt.addr = scatterwalk_map(&walk->out);
5cde0af2
HX
53}
54
55static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
56{
f0dfc0b0 57 scatterwalk_unmap(walk->src.virt.addr);
5cde0af2
HX
58}
59
60static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
61{
f0dfc0b0 62 scatterwalk_unmap(walk->dst.virt.addr);
5cde0af2
HX
63}
64
e4630f9f
HX
65/* Get a spot of the specified length that does not straddle a page.
66 * The caller needs to ensure that there is enough space for this operation.
67 */
5cde0af2
HX
68static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
69{
e4630f9f 70 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
5aaff0c8 71 return max(start, end_page);
5cde0af2
HX
72}
73
822be00f 74static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
5cde0af2
HX
75 unsigned int bsize)
76{
77 u8 *addr;
5cde0af2 78
822be00f 79 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
5cde0af2
HX
80 addr = blkcipher_get_spot(addr, bsize);
81 scatterwalk_copychunks(addr, &walk->out, bsize, 1);
82 return bsize;
83}
84
85static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
86 unsigned int n)
87{
5cde0af2
HX
88 if (walk->flags & BLKCIPHER_WALK_COPY) {
89 blkcipher_map_dst(walk);
90 memcpy(walk->dst.virt.addr, walk->page, n);
91 blkcipher_unmap_dst(walk);
92 } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
5cde0af2
HX
93 if (walk->flags & BLKCIPHER_WALK_DIFF)
94 blkcipher_unmap_dst(walk);
61ecdb80 95 blkcipher_unmap_src(walk);
5cde0af2
HX
96 }
97
98 scatterwalk_advance(&walk->in, n);
99 scatterwalk_advance(&walk->out, n);
100
101 return n;
102}
103
104int blkcipher_walk_done(struct blkcipher_desc *desc,
105 struct blkcipher_walk *walk, int err)
106{
5cde0af2
HX
107 unsigned int nbytes = 0;
108
109 if (likely(err >= 0)) {
7607bd8f 110 unsigned int n = walk->nbytes - err;
5cde0af2
HX
111
112 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
7607bd8f
HX
113 n = blkcipher_done_fast(walk, n);
114 else if (WARN_ON(err)) {
115 err = -EINVAL;
116 goto err;
117 } else
822be00f 118 n = blkcipher_done_slow(walk, n);
5cde0af2
HX
119
120 nbytes = walk->total - n;
121 err = 0;
122 }
123
124 scatterwalk_done(&walk->in, 0, nbytes);
125 scatterwalk_done(&walk->out, 1, nbytes);
126
bac1b5c4 127err:
5cde0af2
HX
128 walk->total = nbytes;
129 walk->nbytes = nbytes;
130
131 if (nbytes) {
132 crypto_yield(desc->flags);
133 return blkcipher_walk_next(desc, walk);
134 }
135
136 if (walk->iv != desc->info)
822be00f 137 memcpy(desc->info, walk->iv, walk->ivsize);
5cde0af2
HX
138 if (walk->buffer != walk->page)
139 kfree(walk->buffer);
140 if (walk->page)
141 free_page((unsigned long)walk->page);
142
143 return err;
144}
145EXPORT_SYMBOL_GPL(blkcipher_walk_done);
146
147static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
148 struct blkcipher_walk *walk,
149 unsigned int bsize,
150 unsigned int alignmask)
151{
152 unsigned int n;
70613783 153 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
5cde0af2
HX
154
155 if (walk->buffer)
156 goto ok;
157
158 walk->buffer = walk->page;
159 if (walk->buffer)
160 goto ok;
161
2614de1b 162 n = aligned_bsize * 3 - (alignmask + 1) +
e4630f9f 163 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
5cde0af2
HX
164 walk->buffer = kmalloc(n, GFP_ATOMIC);
165 if (!walk->buffer)
166 return blkcipher_walk_done(desc, walk, -ENOMEM);
167
168ok:
169 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
170 alignmask + 1);
171 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
70613783
HX
172 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
173 aligned_bsize, bsize);
5cde0af2
HX
174
175 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
176
177 walk->nbytes = bsize;
178 walk->flags |= BLKCIPHER_WALK_SLOW;
179
180 return 0;
181}
182
183static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
184{
185 u8 *tmp = walk->page;
186
187 blkcipher_map_src(walk);
188 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
189 blkcipher_unmap_src(walk);
190
191 walk->src.virt.addr = tmp;
192 walk->dst.virt.addr = tmp;
193
194 return 0;
195}
196
197static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
198 struct blkcipher_walk *walk)
199{
200 unsigned long diff;
201
202 walk->src.phys.page = scatterwalk_page(&walk->in);
203 walk->src.phys.offset = offset_in_page(walk->in.offset);
204 walk->dst.phys.page = scatterwalk_page(&walk->out);
205 walk->dst.phys.offset = offset_in_page(walk->out.offset);
206
207 if (walk->flags & BLKCIPHER_WALK_PHYS)
208 return 0;
209
210 diff = walk->src.phys.offset - walk->dst.phys.offset;
211 diff |= walk->src.virt.page - walk->dst.virt.page;
212
213 blkcipher_map_src(walk);
214 walk->dst.virt.addr = walk->src.virt.addr;
215
216 if (diff) {
217 walk->flags |= BLKCIPHER_WALK_DIFF;
218 blkcipher_map_dst(walk);
219 }
220
221 return 0;
222}
223
224static int blkcipher_walk_next(struct blkcipher_desc *desc,
225 struct blkcipher_walk *walk)
226{
7607bd8f 227 unsigned int bsize;
5cde0af2
HX
228 unsigned int n;
229 int err;
230
231 n = walk->total;
822be00f 232 if (unlikely(n < walk->cipher_blocksize)) {
5cde0af2
HX
233 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
234 return blkcipher_walk_done(desc, walk, -EINVAL);
235 }
236
acdb04d0
HX
237 bsize = min(walk->walk_blocksize, n);
238
5cde0af2
HX
239 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
240 BLKCIPHER_WALK_DIFF);
822be00f
AB
241 if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
242 !scatterwalk_aligned(&walk->out, walk->alignmask)) {
5cde0af2
HX
243 walk->flags |= BLKCIPHER_WALK_COPY;
244 if (!walk->page) {
245 walk->page = (void *)__get_free_page(GFP_ATOMIC);
246 if (!walk->page)
247 n = 0;
248 }
249 }
250
251 n = scatterwalk_clamp(&walk->in, n);
252 n = scatterwalk_clamp(&walk->out, n);
253
254 if (unlikely(n < bsize)) {
822be00f 255 err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
5cde0af2
HX
256 goto set_phys_lowmem;
257 }
258
259 walk->nbytes = n;
260 if (walk->flags & BLKCIPHER_WALK_COPY) {
261 err = blkcipher_next_copy(walk);
262 goto set_phys_lowmem;
263 }
264
265 return blkcipher_next_fast(desc, walk);
266
267set_phys_lowmem:
268 if (walk->flags & BLKCIPHER_WALK_PHYS) {
269 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
270 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
271 walk->src.phys.offset &= PAGE_SIZE - 1;
272 walk->dst.phys.offset &= PAGE_SIZE - 1;
273 }
274 return err;
275}
276
822be00f 277static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
5cde0af2 278{
822be00f
AB
279 unsigned bs = walk->walk_blocksize;
280 unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
281 unsigned int size = aligned_bs * 2 +
282 walk->ivsize + max(aligned_bs, walk->ivsize) -
283 (walk->alignmask + 1);
5cde0af2
HX
284 u8 *iv;
285
822be00f 286 size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
5cde0af2
HX
287 walk->buffer = kmalloc(size, GFP_ATOMIC);
288 if (!walk->buffer)
289 return -ENOMEM;
290
822be00f 291 iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
70613783
HX
292 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
293 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
822be00f 294 iv = blkcipher_get_spot(iv, walk->ivsize);
5cde0af2 295
822be00f 296 walk->iv = memcpy(iv, walk->iv, walk->ivsize);
5cde0af2
HX
297 return 0;
298}
299
300int blkcipher_walk_virt(struct blkcipher_desc *desc,
301 struct blkcipher_walk *walk)
302{
303 walk->flags &= ~BLKCIPHER_WALK_PHYS;
822be00f
AB
304 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
305 walk->cipher_blocksize = walk->walk_blocksize;
306 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
307 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
5cde0af2
HX
308 return blkcipher_walk_first(desc, walk);
309}
310EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
311
312int blkcipher_walk_phys(struct blkcipher_desc *desc,
313 struct blkcipher_walk *walk)
314{
315 walk->flags |= BLKCIPHER_WALK_PHYS;
822be00f
AB
316 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
317 walk->cipher_blocksize = walk->walk_blocksize;
318 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
319 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
5cde0af2
HX
320 return blkcipher_walk_first(desc, walk);
321}
322EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
323
324static int blkcipher_walk_first(struct blkcipher_desc *desc,
325 struct blkcipher_walk *walk)
326{
fb469840
HX
327 if (WARN_ON_ONCE(in_irq()))
328 return -EDEADLK;
329
70d906bc 330 walk->iv = desc->info;
5cde0af2
HX
331 walk->nbytes = walk->total;
332 if (unlikely(!walk->total))
333 return 0;
334
335 walk->buffer = NULL;
822be00f
AB
336 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
337 int err = blkcipher_copy_iv(walk);
5cde0af2
HX
338 if (err)
339 return err;
340 }
341
342 scatterwalk_start(&walk->in, walk->in.sg);
343 scatterwalk_start(&walk->out, walk->out.sg);
344 walk->page = NULL;
345
346 return blkcipher_walk_next(desc, walk);
347}
348
7607bd8f
HX
349int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
350 struct blkcipher_walk *walk,
351 unsigned int blocksize)
352{
353 walk->flags &= ~BLKCIPHER_WALK_PHYS;
822be00f
AB
354 walk->walk_blocksize = blocksize;
355 walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
356 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
357 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
7607bd8f
HX
358 return blkcipher_walk_first(desc, walk);
359}
360EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
361
4f7f1d7c
AB
362int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
363 struct blkcipher_walk *walk,
364 struct crypto_aead *tfm,
365 unsigned int blocksize)
366{
367 walk->flags &= ~BLKCIPHER_WALK_PHYS;
368 walk->walk_blocksize = blocksize;
369 walk->cipher_blocksize = crypto_aead_blocksize(tfm);
370 walk->ivsize = crypto_aead_ivsize(tfm);
371 walk->alignmask = crypto_aead_alignmask(tfm);
372 return blkcipher_walk_first(desc, walk);
373}
374EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block);
375
791b4d5f
HX
376static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
377 unsigned int keylen)
ca7c3938
SS
378{
379 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
380 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
381 int ret;
382 u8 *buffer, *alignbuffer;
383 unsigned long absize;
384
385 absize = keylen + alignmask;
386 buffer = kmalloc(absize, GFP_ATOMIC);
387 if (!buffer)
388 return -ENOMEM;
389
390 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
391 memcpy(alignbuffer, key, keylen);
392 ret = cipher->setkey(tfm, alignbuffer, keylen);
06817176 393 memset(alignbuffer, 0, keylen);
ca7c3938
SS
394 kfree(buffer);
395 return ret;
396}
397
791b4d5f 398static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
5cde0af2
HX
399{
400 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
ca7c3938 401 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
5cde0af2
HX
402
403 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
404 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
405 return -EINVAL;
406 }
407
ca7c3938
SS
408 if ((unsigned long)key & alignmask)
409 return setkey_unaligned(tfm, key, keylen);
410
5cde0af2
HX
411 return cipher->setkey(tfm, key, keylen);
412}
413
32e3983f
HX
414static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
415 unsigned int keylen)
416{
417 return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
418}
419
420static int async_encrypt(struct ablkcipher_request *req)
421{
422 struct crypto_tfm *tfm = req->base.tfm;
423 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
424 struct blkcipher_desc desc = {
425 .tfm = __crypto_blkcipher_cast(tfm),
426 .info = req->info,
427 .flags = req->base.flags,
428 };
429
430
431 return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
432}
433
434static int async_decrypt(struct ablkcipher_request *req)
435{
436 struct crypto_tfm *tfm = req->base.tfm;
437 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
438 struct blkcipher_desc desc = {
439 .tfm = __crypto_blkcipher_cast(tfm),
440 .info = req->info,
441 .flags = req->base.flags,
442 };
443
444 return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
445}
446
27d2a330
HX
447static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
448 u32 mask)
5cde0af2
HX
449{
450 struct blkcipher_alg *cipher = &alg->cra_blkcipher;
451 unsigned int len = alg->cra_ctxsize;
452
332f8840
HX
453 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
454 cipher->ivsize) {
5cde0af2
HX
455 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
456 len += cipher->ivsize;
457 }
458
459 return len;
460}
461
32e3983f
HX
462static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
463{
464 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
465 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
466
467 crt->setkey = async_setkey;
468 crt->encrypt = async_encrypt;
469 crt->decrypt = async_decrypt;
ecfc4329 470 crt->base = __crypto_ablkcipher_cast(tfm);
32e3983f
HX
471 crt->ivsize = alg->ivsize;
472
473 return 0;
474}
475
476static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
5cde0af2
HX
477{
478 struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
479 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
480 unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
481 unsigned long addr;
482
5cde0af2
HX
483 crt->setkey = setkey;
484 crt->encrypt = alg->encrypt;
485 crt->decrypt = alg->decrypt;
486
487 addr = (unsigned long)crypto_tfm_ctx(tfm);
488 addr = ALIGN(addr, align);
489 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
490 crt->iv = (void *)addr;
491
492 return 0;
493}
494
32e3983f
HX
495static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
496{
497 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
498
499 if (alg->ivsize > PAGE_SIZE / 8)
500 return -EINVAL;
501
332f8840 502 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
32e3983f
HX
503 return crypto_init_blkcipher_ops_sync(tfm);
504 else
505 return crypto_init_blkcipher_ops_async(tfm);
506}
507
3acc8473 508#ifdef CONFIG_NET
50496a1f
SK
509static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
510{
511 struct crypto_report_blkcipher rblkcipher;
512
9a5467bf
MK
513 strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
514 strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
515 sizeof(rblkcipher.geniv));
50496a1f
SK
516
517 rblkcipher.blocksize = alg->cra_blocksize;
518 rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
519 rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
520 rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
521
6662df33
DM
522 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
523 sizeof(struct crypto_report_blkcipher), &rblkcipher))
524 goto nla_put_failure;
50496a1f
SK
525 return 0;
526
527nla_put_failure:
528 return -EMSGSIZE;
529}
3acc8473
HX
530#else
531static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
532{
533 return -ENOSYS;
534}
535#endif
50496a1f 536
5cde0af2 537static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
d8c34b94 538 __maybe_unused;
5cde0af2
HX
539static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
540{
541 seq_printf(m, "type : blkcipher\n");
542 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
543 seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
544 seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
545 seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
23508e11
HX
546 seq_printf(m, "geniv : %s\n", alg->cra_blkcipher.geniv ?:
547 "<default>");
5cde0af2
HX
548}
549
550const struct crypto_type crypto_blkcipher_type = {
551 .ctxsize = crypto_blkcipher_ctxsize,
552 .init = crypto_init_blkcipher_ops,
553#ifdef CONFIG_PROC_FS
554 .show = crypto_blkcipher_show,
555#endif
50496a1f 556 .report = crypto_blkcipher_report,
5cde0af2
HX
557};
558EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
559
560MODULE_LICENSE("GPL");
561MODULE_DESCRIPTION("Generic block chaining cipher type");