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