projects/linux·blob v3.13 · refs

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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 <[email protected]>
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/internal/skcipher.h>
18#include <crypto/scatterwalk.h>
19#include <linux/errno.h>
20#include <linux/hardirq.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/scatterlist.h>
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/cryptouser.h>
28#include <net/netlink.h>
29
30#include "internal.h"
31
32enum {
33 BLKCIPHER_WALK_PHYS = 1 << 0,
34 BLKCIPHER_WALK_SLOW = 1 << 1,
35 BLKCIPHER_WALK_COPY = 1 << 2,
36 BLKCIPHER_WALK_DIFF = 1 << 3,
37};
38
39static int blkcipher_walk_next(struct blkcipher_desc *desc,
40 struct blkcipher_walk *walk);
41static int blkcipher_walk_first(struct blkcipher_desc *desc,
42 struct blkcipher_walk *walk);
43
44static inline void blkcipher_map_src(struct blkcipher_walk *walk)
45{
46 walk->src.virt.addr = scatterwalk_map(&walk->in);
47}
48
49static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
50{
51 walk->dst.virt.addr = scatterwalk_map(&walk->out);
52}
53
54static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
55{
56 scatterwalk_unmap(walk->src.virt.addr);
57}
58
59static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
60{
61 scatterwalk_unmap(walk->dst.virt.addr);
62}
63
64/* Get a spot of the specified length that does not straddle a page.
65 * The caller needs to ensure that there is enough space for this operation.
66 */
67static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
68{
69 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
70 return max(start, end_page);
71}
72
73static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
74 struct blkcipher_walk *walk,
75 unsigned int bsize)
76{
77 u8 *addr;
78 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
79
80 addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
81 addr = blkcipher_get_spot(addr, bsize);
82 scatterwalk_copychunks(addr, &walk->out, bsize, 1);
83 return bsize;
84}
85
86static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
87 unsigned int n)
88{
89 if (walk->flags & BLKCIPHER_WALK_COPY) {
90 blkcipher_map_dst(walk);
91 memcpy(walk->dst.virt.addr, walk->page, n);
92 blkcipher_unmap_dst(walk);
93 } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
94 if (walk->flags & BLKCIPHER_WALK_DIFF)
95 blkcipher_unmap_dst(walk);
96 blkcipher_unmap_src(walk);
97 }
98
99 scatterwalk_advance(&walk->in, n);
100 scatterwalk_advance(&walk->out, n);
101
102 return n;
103}
104
105int blkcipher_walk_done(struct blkcipher_desc *desc,
106 struct blkcipher_walk *walk, int err)
107{
108 struct crypto_blkcipher *tfm = desc->tfm;
109 unsigned int nbytes = 0;
110
111 if (likely(err >= 0)) {
112 unsigned int n = walk->nbytes - err;
113
114 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
115 n = blkcipher_done_fast(walk, n);
116 else if (WARN_ON(err)) {
117 err = -EINVAL;
118 goto err;
119 } else
120 n = blkcipher_done_slow(tfm, walk, n);
121
122 nbytes = walk->total - n;
123 err = 0;
124 }
125
126 scatterwalk_done(&walk->in, 0, nbytes);
127 scatterwalk_done(&walk->out, 1, nbytes);
128
129err:
130 walk->total = nbytes;
131 walk->nbytes = nbytes;
132
133 if (nbytes) {
134 crypto_yield(desc->flags);
135 return blkcipher_walk_next(desc, walk);
136 }
137
138 if (walk->iv != desc->info)
139 memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
140 if (walk->buffer != walk->page)
141 kfree(walk->buffer);
142 if (walk->page)
143 free_page((unsigned long)walk->page);
144
145 return err;
146}
147EXPORT_SYMBOL_GPL(blkcipher_walk_done);
148
149static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
150 struct blkcipher_walk *walk,
151 unsigned int bsize,
152 unsigned int alignmask)
153{
154 unsigned int n;
155 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
156
157 if (walk->buffer)
158 goto ok;
159
160 walk->buffer = walk->page;
161 if (walk->buffer)
162 goto ok;
163
164 n = aligned_bsize * 3 - (alignmask + 1) +
165 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
166 walk->buffer = kmalloc(n, GFP_ATOMIC);
167 if (!walk->buffer)
168 return blkcipher_walk_done(desc, walk, -ENOMEM);
169
170ok:
171 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
172 alignmask + 1);
173 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
174 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
175 aligned_bsize, bsize);
176
177 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
178
179 walk->nbytes = bsize;
180 walk->flags |= BLKCIPHER_WALK_SLOW;
181
182 return 0;
183}
184
185static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
186{
187 u8 *tmp = walk->page;
188
189 blkcipher_map_src(walk);
190 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
191 blkcipher_unmap_src(walk);
192
193 walk->src.virt.addr = tmp;
194 walk->dst.virt.addr = tmp;
195
196 return 0;
197}
198
199static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
200 struct blkcipher_walk *walk)
201{
202 unsigned long diff;
203
204 walk->src.phys.page = scatterwalk_page(&walk->in);
205 walk->src.phys.offset = offset_in_page(walk->in.offset);
206 walk->dst.phys.page = scatterwalk_page(&walk->out);
207 walk->dst.phys.offset = offset_in_page(walk->out.offset);
208
209 if (walk->flags & BLKCIPHER_WALK_PHYS)
210 return 0;
211
212 diff = walk->src.phys.offset - walk->dst.phys.offset;
213 diff |= walk->src.virt.page - walk->dst.virt.page;
214
215 blkcipher_map_src(walk);
216 walk->dst.virt.addr = walk->src.virt.addr;
217
218 if (diff) {
219 walk->flags |= BLKCIPHER_WALK_DIFF;
220 blkcipher_map_dst(walk);
221 }
222
223 return 0;
224}
225
226static int blkcipher_walk_next(struct blkcipher_desc *desc,
227 struct blkcipher_walk *walk)
228{
229 struct crypto_blkcipher *tfm = desc->tfm;
230 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
231 unsigned int bsize;
232 unsigned int n;
233 int err;
234
235 n = walk->total;
236 if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
237 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
238 return blkcipher_walk_done(desc, walk, -EINVAL);
239 }
240
241 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
242 BLKCIPHER_WALK_DIFF);
243 if (!scatterwalk_aligned(&walk->in, alignmask) ||
244 !scatterwalk_aligned(&walk->out, alignmask)) {
245 walk->flags |= BLKCIPHER_WALK_COPY;
246 if (!walk->page) {
247 walk->page = (void *)__get_free_page(GFP_ATOMIC);
248 if (!walk->page)
249 n = 0;
250 }
251 }
252
253 bsize = min(walk->blocksize, n);
254 n = scatterwalk_clamp(&walk->in, n);
255 n = scatterwalk_clamp(&walk->out, n);
256
257 if (unlikely(n < bsize)) {
258 err = blkcipher_next_slow(desc, walk, bsize, alignmask);
259 goto set_phys_lowmem;
260 }
261
262 walk->nbytes = n;
263 if (walk->flags & BLKCIPHER_WALK_COPY) {
264 err = blkcipher_next_copy(walk);
265 goto set_phys_lowmem;
266 }
267
268 return blkcipher_next_fast(desc, walk);
269
270set_phys_lowmem:
271 if (walk->flags & BLKCIPHER_WALK_PHYS) {
272 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
273 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
274 walk->src.phys.offset &= PAGE_SIZE - 1;
275 walk->dst.phys.offset &= PAGE_SIZE - 1;
276 }
277 return err;
278}
279
280static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
281 struct crypto_blkcipher *tfm,
282 unsigned int alignmask)
283{
284 unsigned bs = walk->blocksize;
285 unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
286 unsigned aligned_bs = ALIGN(bs, alignmask + 1);
287 unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
288 (alignmask + 1);
289 u8 *iv;
290
291 size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
292 walk->buffer = kmalloc(size, GFP_ATOMIC);
293 if (!walk->buffer)
294 return -ENOMEM;
295
296 iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
297 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
298 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
299 iv = blkcipher_get_spot(iv, ivsize);
300
301 walk->iv = memcpy(iv, walk->iv, ivsize);
302 return 0;
303}
304
305int blkcipher_walk_virt(struct blkcipher_desc *desc,
306 struct blkcipher_walk *walk)
307{
308 walk->flags &= ~BLKCIPHER_WALK_PHYS;
309 walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
310 return blkcipher_walk_first(desc, walk);
311}
312EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
313
314int blkcipher_walk_phys(struct blkcipher_desc *desc,
315 struct blkcipher_walk *walk)
316{
317 walk->flags |= BLKCIPHER_WALK_PHYS;
318 walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
319 return blkcipher_walk_first(desc, walk);
320}
321EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
322
323static int blkcipher_walk_first(struct blkcipher_desc *desc,
324 struct blkcipher_walk *walk)
325{
326 struct crypto_blkcipher *tfm = desc->tfm;
327 unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
328
329 if (WARN_ON_ONCE(in_irq()))
330 return -EDEADLK;
331
332 walk->nbytes = walk->total;
333 if (unlikely(!walk->total))
334 return 0;
335
336 walk->buffer = NULL;
337 walk->iv = desc->info;
338 if (unlikely(((unsigned long)walk->iv & alignmask))) {
339 int err = blkcipher_copy_iv(walk, tfm, alignmask);
340 if (err)
341 return err;
342 }
343
344 scatterwalk_start(&walk->in, walk->in.sg);
345 scatterwalk_start(&walk->out, walk->out.sg);
346 walk->page = NULL;
347
348 return blkcipher_walk_next(desc, walk);
349}
350
351int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
352 struct blkcipher_walk *walk,
353 unsigned int blocksize)
354{
355 walk->flags &= ~BLKCIPHER_WALK_PHYS;
356 walk->blocksize = blocksize;
357 return blkcipher_walk_first(desc, walk);
358}
359EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
360
361static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
362 unsigned int keylen)
363{
364 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
365 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
366 int ret;
367 u8 *buffer, *alignbuffer;
368 unsigned long absize;
369
370 absize = keylen + alignmask;
371 buffer = kmalloc(absize, GFP_ATOMIC);
372 if (!buffer)
373 return -ENOMEM;
374
375 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
376 memcpy(alignbuffer, key, keylen);
377 ret = cipher->setkey(tfm, alignbuffer, keylen);
378 memset(alignbuffer, 0, keylen);
379 kfree(buffer);
380 return ret;
381}
382
383static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
384{
385 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
386 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
387
388 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
389 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
390 return -EINVAL;
391 }
392
393 if ((unsigned long)key & alignmask)
394 return setkey_unaligned(tfm, key, keylen);
395
396 return cipher->setkey(tfm, key, keylen);
397}
398
399static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
400 unsigned int keylen)
401{
402 return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
403}
404
405static int async_encrypt(struct ablkcipher_request *req)
406{
407 struct crypto_tfm *tfm = req->base.tfm;
408 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
409 struct blkcipher_desc desc = {
410 .tfm = __crypto_blkcipher_cast(tfm),
411 .info = req->info,
412 .flags = req->base.flags,
413 };
414
415
416 return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
417}
418
419static int async_decrypt(struct ablkcipher_request *req)
420{
421 struct crypto_tfm *tfm = req->base.tfm;
422 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
423 struct blkcipher_desc desc = {
424 .tfm = __crypto_blkcipher_cast(tfm),
425 .info = req->info,
426 .flags = req->base.flags,
427 };
428
429 return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
430}
431
432static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
433 u32 mask)
434{
435 struct blkcipher_alg *cipher = &alg->cra_blkcipher;
436 unsigned int len = alg->cra_ctxsize;
437
438 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
439 cipher->ivsize) {
440 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
441 len += cipher->ivsize;
442 }
443
444 return len;
445}
446
447static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
448{
449 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
450 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
451
452 crt->setkey = async_setkey;
453 crt->encrypt = async_encrypt;
454 crt->decrypt = async_decrypt;
455 if (!alg->ivsize) {
456 crt->givencrypt = skcipher_null_givencrypt;
457 crt->givdecrypt = skcipher_null_givdecrypt;
458 }
459 crt->base = __crypto_ablkcipher_cast(tfm);
460 crt->ivsize = alg->ivsize;
461
462 return 0;
463}
464
465static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
466{
467 struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
468 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
469 unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
470 unsigned long addr;
471
472 crt->setkey = setkey;
473 crt->encrypt = alg->encrypt;
474 crt->decrypt = alg->decrypt;
475
476 addr = (unsigned long)crypto_tfm_ctx(tfm);
477 addr = ALIGN(addr, align);
478 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
479 crt->iv = (void *)addr;
480
481 return 0;
482}
483
484static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
485{
486 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
487
488 if (alg->ivsize > PAGE_SIZE / 8)
489 return -EINVAL;
490
491 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
492 return crypto_init_blkcipher_ops_sync(tfm);
493 else
494 return crypto_init_blkcipher_ops_async(tfm);
495}
496
497#ifdef CONFIG_NET
498static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
499{
500 struct crypto_report_blkcipher rblkcipher;
501
502 strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
503 strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
504 sizeof(rblkcipher.geniv));
505
506 rblkcipher.blocksize = alg->cra_blocksize;
507 rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
508 rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
509 rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
510
511 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
512 sizeof(struct crypto_report_blkcipher), &rblkcipher))
513 goto nla_put_failure;
514 return 0;
515
516nla_put_failure:
517 return -EMSGSIZE;
518}
519#else
520static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
521{
522 return -ENOSYS;
523}
524#endif
525
526static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
527 __attribute__ ((unused));
528static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
529{
530 seq_printf(m, "type : blkcipher\n");
531 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
532 seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
533 seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
534 seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
535 seq_printf(m, "geniv : %s\n", alg->cra_blkcipher.geniv ?:
536 "<default>");
537}
538
539const struct crypto_type crypto_blkcipher_type = {
540 .ctxsize = crypto_blkcipher_ctxsize,
541 .init = crypto_init_blkcipher_ops,
542#ifdef CONFIG_PROC_FS
543 .show = crypto_blkcipher_show,
544#endif
545 .report = crypto_blkcipher_report,
546};
547EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
548
549static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
550 const char *name, u32 type, u32 mask)
551{
552 struct crypto_alg *alg;
553 int err;
554
555 type = crypto_skcipher_type(type);
556 mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
557
558 alg = crypto_alg_mod_lookup(name, type, mask);
559 if (IS_ERR(alg))
560 return PTR_ERR(alg);
561
562 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
563 crypto_mod_put(alg);
564 return err;
565}
566
567struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
568 struct rtattr **tb, u32 type,
569 u32 mask)
570{
571 struct {
572 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
573 unsigned int keylen);
574 int (*encrypt)(struct ablkcipher_request *req);
575 int (*decrypt)(struct ablkcipher_request *req);
576
577 unsigned int min_keysize;
578 unsigned int max_keysize;
579 unsigned int ivsize;
580
581 const char *geniv;
582 } balg;
583 const char *name;
584 struct crypto_skcipher_spawn *spawn;
585 struct crypto_attr_type *algt;
586 struct crypto_instance *inst;
587 struct crypto_alg *alg;
588 int err;
589
590 algt = crypto_get_attr_type(tb);
591 if (IS_ERR(algt))
592 return ERR_CAST(algt);
593
594 if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
595 algt->mask)
596 return ERR_PTR(-EINVAL);
597
598 name = crypto_attr_alg_name(tb[1]);
599 if (IS_ERR(name))
600 return ERR_CAST(name);
601
602 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
603 if (!inst)
604 return ERR_PTR(-ENOMEM);
605
606 spawn = crypto_instance_ctx(inst);
607
608 /* Ignore async algorithms if necessary. */
609 mask |= crypto_requires_sync(algt->type, algt->mask);
610
611 crypto_set_skcipher_spawn(spawn, inst);
612 err = crypto_grab_nivcipher(spawn, name, type, mask);
613 if (err)
614 goto err_free_inst;
615
616 alg = crypto_skcipher_spawn_alg(spawn);
617
618 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
619 CRYPTO_ALG_TYPE_BLKCIPHER) {
620 balg.ivsize = alg->cra_blkcipher.ivsize;
621 balg.min_keysize = alg->cra_blkcipher.min_keysize;
622 balg.max_keysize = alg->cra_blkcipher.max_keysize;
623
624 balg.setkey = async_setkey;
625 balg.encrypt = async_encrypt;
626 balg.decrypt = async_decrypt;
627
628 balg.geniv = alg->cra_blkcipher.geniv;
629 } else {
630 balg.ivsize = alg->cra_ablkcipher.ivsize;
631 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
632 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
633
634 balg.setkey = alg->cra_ablkcipher.setkey;
635 balg.encrypt = alg->cra_ablkcipher.encrypt;
636 balg.decrypt = alg->cra_ablkcipher.decrypt;
637
638 balg.geniv = alg->cra_ablkcipher.geniv;
639 }
640
641 err = -EINVAL;
642 if (!balg.ivsize)
643 goto err_drop_alg;
644
645 /*
646 * This is only true if we're constructing an algorithm with its
647 * default IV generator. For the default generator we elide the
648 * template name and double-check the IV generator.
649 */
650 if (algt->mask & CRYPTO_ALG_GENIV) {
651 if (!balg.geniv)
652 balg.geniv = crypto_default_geniv(alg);
653 err = -EAGAIN;
654 if (strcmp(tmpl->name, balg.geniv))
655 goto err_drop_alg;
656
657 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
658 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
659 CRYPTO_MAX_ALG_NAME);
660 } else {
661 err = -ENAMETOOLONG;
662 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
663 "%s(%s)", tmpl->name, alg->cra_name) >=
664 CRYPTO_MAX_ALG_NAME)
665 goto err_drop_alg;
666 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
667 "%s(%s)", tmpl->name, alg->cra_driver_name) >=
668 CRYPTO_MAX_ALG_NAME)
669 goto err_drop_alg;
670 }
671
672 inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
673 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
674 inst->alg.cra_priority = alg->cra_priority;
675 inst->alg.cra_blocksize = alg->cra_blocksize;
676 inst->alg.cra_alignmask = alg->cra_alignmask;
677 inst->alg.cra_type = &crypto_givcipher_type;
678
679 inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
680 inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
681 inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
682 inst->alg.cra_ablkcipher.geniv = balg.geniv;
683
684 inst->alg.cra_ablkcipher.setkey = balg.setkey;
685 inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
686 inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
687
688out:
689 return inst;
690
691err_drop_alg:
692 crypto_drop_skcipher(spawn);
693err_free_inst:
694 kfree(inst);
695 inst = ERR_PTR(err);
696 goto out;
697}
698EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
699
700void skcipher_geniv_free(struct crypto_instance *inst)
701{
702 crypto_drop_skcipher(crypto_instance_ctx(inst));
703 kfree(inst);
704}
705EXPORT_SYMBOL_GPL(skcipher_geniv_free);
706
707int skcipher_geniv_init(struct crypto_tfm *tfm)
708{
709 struct crypto_instance *inst = (void *)tfm->__crt_alg;
710 struct crypto_ablkcipher *cipher;
711
712 cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
713 if (IS_ERR(cipher))
714 return PTR_ERR(cipher);
715
716 tfm->crt_ablkcipher.base = cipher;
717 tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
718
719 return 0;
720}
721EXPORT_SYMBOL_GPL(skcipher_geniv_init);
722
723void skcipher_geniv_exit(struct crypto_tfm *tfm)
724{
725 crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
726}
727EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
728
729MODULE_LICENSE("GPL");
730MODULE_DESCRIPTION("Generic block chaining cipher type");