asymmetric keys: fix printk format warning
[linux-3.10.git] / crypto / blkcipher.c
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/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
32 enum {
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
39 static int blkcipher_walk_next(struct blkcipher_desc *desc,
40                                struct blkcipher_walk *walk);
41 static int blkcipher_walk_first(struct blkcipher_desc *desc,
42                                 struct blkcipher_walk *walk);
43
44 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
45 {
46         walk->src.virt.addr = scatterwalk_map(&walk->in);
47 }
48
49 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
50 {
51         walk->dst.virt.addr = scatterwalk_map(&walk->out);
52 }
53
54 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
55 {
56         scatterwalk_unmap(walk->src.virt.addr);
57 }
58
59 static 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  */
67 static 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
73 static 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
86 static 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
105 int 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
129 err:
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 }
147 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
148
149 static 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
170 ok:
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
185 static 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
199 static 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
226 static 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
270 set_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
280 static 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
305 int 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 }
312 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
313
314 int 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 }
321 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
322
323 static 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
351 int 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 }
359 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
360
361 static 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
383 static 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
399 static 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
405 static 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
419 static 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
432 static 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
447 static 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
465 static 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
484 static 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
498 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
499 {
500         struct crypto_report_blkcipher rblkcipher;
501
502         snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "blkcipher");
503         snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
504                  alg->cra_blkcipher.geniv ?: "<default>");
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
516 nla_put_failure:
517         return -EMSGSIZE;
518 }
519 #else
520 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
521 {
522         return -ENOSYS;
523 }
524 #endif
525
526 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
527         __attribute__ ((unused));
528 static 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
539 const 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 };
547 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
548
549 static 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
567 struct 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         err = PTR_ERR(algt);
592         if (IS_ERR(algt))
593                 return ERR_PTR(err);
594
595         if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
596             algt->mask)
597                 return ERR_PTR(-EINVAL);
598
599         name = crypto_attr_alg_name(tb[1]);
600         err = PTR_ERR(name);
601         if (IS_ERR(name))
602                 return ERR_PTR(err);
603
604         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
605         if (!inst)
606                 return ERR_PTR(-ENOMEM);
607
608         spawn = crypto_instance_ctx(inst);
609
610         /* Ignore async algorithms if necessary. */
611         mask |= crypto_requires_sync(algt->type, algt->mask);
612
613         crypto_set_skcipher_spawn(spawn, inst);
614         err = crypto_grab_nivcipher(spawn, name, type, mask);
615         if (err)
616                 goto err_free_inst;
617
618         alg = crypto_skcipher_spawn_alg(spawn);
619
620         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
621             CRYPTO_ALG_TYPE_BLKCIPHER) {
622                 balg.ivsize = alg->cra_blkcipher.ivsize;
623                 balg.min_keysize = alg->cra_blkcipher.min_keysize;
624                 balg.max_keysize = alg->cra_blkcipher.max_keysize;
625
626                 balg.setkey = async_setkey;
627                 balg.encrypt = async_encrypt;
628                 balg.decrypt = async_decrypt;
629
630                 balg.geniv = alg->cra_blkcipher.geniv;
631         } else {
632                 balg.ivsize = alg->cra_ablkcipher.ivsize;
633                 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
634                 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
635
636                 balg.setkey = alg->cra_ablkcipher.setkey;
637                 balg.encrypt = alg->cra_ablkcipher.encrypt;
638                 balg.decrypt = alg->cra_ablkcipher.decrypt;
639
640                 balg.geniv = alg->cra_ablkcipher.geniv;
641         }
642
643         err = -EINVAL;
644         if (!balg.ivsize)
645                 goto err_drop_alg;
646
647         /*
648          * This is only true if we're constructing an algorithm with its
649          * default IV generator.  For the default generator we elide the
650          * template name and double-check the IV generator.
651          */
652         if (algt->mask & CRYPTO_ALG_GENIV) {
653                 if (!balg.geniv)
654                         balg.geniv = crypto_default_geniv(alg);
655                 err = -EAGAIN;
656                 if (strcmp(tmpl->name, balg.geniv))
657                         goto err_drop_alg;
658
659                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
660                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
661                        CRYPTO_MAX_ALG_NAME);
662         } else {
663                 err = -ENAMETOOLONG;
664                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
665                              "%s(%s)", tmpl->name, alg->cra_name) >=
666                     CRYPTO_MAX_ALG_NAME)
667                         goto err_drop_alg;
668                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
669                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
670                     CRYPTO_MAX_ALG_NAME)
671                         goto err_drop_alg;
672         }
673
674         inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
675         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
676         inst->alg.cra_priority = alg->cra_priority;
677         inst->alg.cra_blocksize = alg->cra_blocksize;
678         inst->alg.cra_alignmask = alg->cra_alignmask;
679         inst->alg.cra_type = &crypto_givcipher_type;
680
681         inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
682         inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
683         inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
684         inst->alg.cra_ablkcipher.geniv = balg.geniv;
685
686         inst->alg.cra_ablkcipher.setkey = balg.setkey;
687         inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
688         inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
689
690 out:
691         return inst;
692
693 err_drop_alg:
694         crypto_drop_skcipher(spawn);
695 err_free_inst:
696         kfree(inst);
697         inst = ERR_PTR(err);
698         goto out;
699 }
700 EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
701
702 void skcipher_geniv_free(struct crypto_instance *inst)
703 {
704         crypto_drop_skcipher(crypto_instance_ctx(inst));
705         kfree(inst);
706 }
707 EXPORT_SYMBOL_GPL(skcipher_geniv_free);
708
709 int skcipher_geniv_init(struct crypto_tfm *tfm)
710 {
711         struct crypto_instance *inst = (void *)tfm->__crt_alg;
712         struct crypto_ablkcipher *cipher;
713
714         cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
715         if (IS_ERR(cipher))
716                 return PTR_ERR(cipher);
717
718         tfm->crt_ablkcipher.base = cipher;
719         tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
720
721         return 0;
722 }
723 EXPORT_SYMBOL_GPL(skcipher_geniv_init);
724
725 void skcipher_geniv_exit(struct crypto_tfm *tfm)
726 {
727         crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
728 }
729 EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
730
731 MODULE_LICENSE("GPL");
732 MODULE_DESCRIPTION("Generic block chaining cipher type");