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TOMOYO Linux Cross Reference
Linux/crypto/blkcipher.c

Version: ~ [ linux-5.15-rc6 ] ~ [ linux-5.14.14 ] ~ [ linux-5.13.19 ] ~ [ linux-5.12.19 ] ~ [ linux-5.11.22 ] ~ [ linux-5.10.75 ] ~ [ linux-5.9.16 ] ~ [ linux-5.8.18 ] ~ [ linux-5.7.19 ] ~ [ linux-5.6.19 ] ~ [ linux-5.5.19 ] ~ [ linux-5.4.155 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.213 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.252 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.287 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.289 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.18.140 ] ~ [ linux-3.16.85 ] ~ [ linux-3.14.79 ] ~ [ linux-3.12.74 ] ~ [ linux-3.10.108 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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/scatterlist.h>
 25 #include <linux/seq_file.h>
 26 #include <linux/slab.h>
 27 #include <linux/string.h>
 28 #include <linux/cryptouser.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 
 45 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
 46 {
 47         walk->src.virt.addr = scatterwalk_map(&walk->in);
 48 }
 49 
 50 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
 51 {
 52         walk->dst.virt.addr = scatterwalk_map(&walk->out);
 53 }
 54 
 55 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
 56 {
 57         scatterwalk_unmap(walk->src.virt.addr);
 58 }
 59 
 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  */
 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 
 74 static inline unsigned int 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         return bsize;
 83 }
 84 
 85 static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
 86                                                unsigned int n)
 87 {
 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)) {
 93                 if (walk->flags & BLKCIPHER_WALK_DIFF)
 94                         blkcipher_unmap_dst(walk);
 95                 blkcipher_unmap_src(walk);
 96         }
 97 
 98         scatterwalk_advance(&walk->in, n);
 99         scatterwalk_advance(&walk->out, n);
100 
101         return n;
102 }
103 
104 int blkcipher_walk_done(struct blkcipher_desc *desc,
105                         struct blkcipher_walk *walk, int err)
106 {
107         unsigned int nbytes = 0;
108 
109         if (likely(err >= 0)) {
110                 unsigned int n = walk->nbytes - err;
111 
112                 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
113                         n = blkcipher_done_fast(walk, n);
114                 else if (WARN_ON(err)) {
115                         err = -EINVAL;
116                         goto err;
117                 } else
118                         n = blkcipher_done_slow(walk, n);
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 
127 err:
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)
137                 memcpy(desc->info, walk->iv, walk->ivsize);
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 }
145 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
146 
147 static 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;
153         unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
154 
155         if (walk->buffer)
156                 goto ok;
157 
158         walk->buffer = walk->page;
159         if (walk->buffer)
160                 goto ok;
161 
162         n = aligned_bsize * 3 - (alignmask + 1) +
163             (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
164         walk->buffer = kmalloc(n, GFP_ATOMIC);
165         if (!walk->buffer)
166                 return blkcipher_walk_done(desc, walk, -ENOMEM);
167 
168 ok:
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);
172         walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
173                                                  aligned_bsize, bsize);
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 
183 static 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 
197 static 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 
224 static int blkcipher_walk_next(struct blkcipher_desc *desc,
225                                struct blkcipher_walk *walk)
226 {
227         unsigned int bsize;
228         unsigned int n;
229         int err;
230 
231         n = walk->total;
232         if (unlikely(n < walk->cipher_blocksize)) {
233                 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
234                 return blkcipher_walk_done(desc, walk, -EINVAL);
235         }
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         bsize = min(walk->walk_blocksize, n);
250         n = scatterwalk_clamp(&walk->in, n);
251         n = scatterwalk_clamp(&walk->out, n);
252 
253         if (unlikely(n < bsize)) {
254                 err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
255                 goto set_phys_lowmem;
256         }
257 
258         walk->nbytes = n;
259         if (walk->flags & BLKCIPHER_WALK_COPY) {
260                 err = blkcipher_next_copy(walk);
261                 goto set_phys_lowmem;
262         }
263 
264         return blkcipher_next_fast(desc, walk);
265 
266 set_phys_lowmem:
267         if (walk->flags & BLKCIPHER_WALK_PHYS) {
268                 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
269                 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
270                 walk->src.phys.offset &= PAGE_SIZE - 1;
271                 walk->dst.phys.offset &= PAGE_SIZE - 1;
272         }
273         return err;
274 }
275 
276 static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
277 {
278         unsigned bs = walk->walk_blocksize;
279         unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
280         unsigned int size = aligned_bs * 2 +
281                             walk->ivsize + max(aligned_bs, walk->ivsize) -
282                             (walk->alignmask + 1);
283         u8 *iv;
284 
285         size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
286         walk->buffer = kmalloc(size, GFP_ATOMIC);
287         if (!walk->buffer)
288                 return -ENOMEM;
289 
290         iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
291         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
292         iv = blkcipher_get_spot(iv, bs) + aligned_bs;
293         iv = blkcipher_get_spot(iv, walk->ivsize);
294 
295         walk->iv = memcpy(iv, walk->iv, walk->ivsize);
296         return 0;
297 }
298 
299 int blkcipher_walk_virt(struct blkcipher_desc *desc,
300                         struct blkcipher_walk *walk)
301 {
302         walk->flags &= ~BLKCIPHER_WALK_PHYS;
303         walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
304         walk->cipher_blocksize = walk->walk_blocksize;
305         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
306         walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
307         return blkcipher_walk_first(desc, walk);
308 }
309 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
310 
311 int blkcipher_walk_phys(struct blkcipher_desc *desc,
312                         struct blkcipher_walk *walk)
313 {
314         walk->flags |= BLKCIPHER_WALK_PHYS;
315         walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
316         walk->cipher_blocksize = walk->walk_blocksize;
317         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
318         walk->alignmask = crypto_blkcipher_alignmask(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         if (WARN_ON_ONCE(in_irq()))
327                 return -EDEADLK;
328 
329         walk->iv = desc->info;
330         walk->nbytes = walk->total;
331         if (unlikely(!walk->total))
332                 return 0;
333 
334         walk->buffer = NULL;
335         if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
336                 int err = blkcipher_copy_iv(walk);
337                 if (err)
338                         return err;
339         }
340 
341         scatterwalk_start(&walk->in, walk->in.sg);
342         scatterwalk_start(&walk->out, walk->out.sg);
343         walk->page = NULL;
344 
345         return blkcipher_walk_next(desc, walk);
346 }
347 
348 int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
349                               struct blkcipher_walk *walk,
350                               unsigned int blocksize)
351 {
352         walk->flags &= ~BLKCIPHER_WALK_PHYS;
353         walk->walk_blocksize = blocksize;
354         walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
355         walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
356         walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
357         return blkcipher_walk_first(desc, walk);
358 }
359 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
360 
361 int blkcipher_aead_walk_virt_block(struct blkcipher_desc *desc,
362                                    struct blkcipher_walk *walk,
363                                    struct crypto_aead *tfm,
364                                    unsigned int blocksize)
365 {
366         walk->flags &= ~BLKCIPHER_WALK_PHYS;
367         walk->walk_blocksize = blocksize;
368         walk->cipher_blocksize = crypto_aead_blocksize(tfm);
369         walk->ivsize = crypto_aead_ivsize(tfm);
370         walk->alignmask = crypto_aead_alignmask(tfm);
371         return blkcipher_walk_first(desc, walk);
372 }
373 EXPORT_SYMBOL_GPL(blkcipher_aead_walk_virt_block);
374 
375 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
376                             unsigned int keylen)
377 {
378         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
379         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
380         int ret;
381         u8 *buffer, *alignbuffer;
382         unsigned long absize;
383 
384         absize = keylen + alignmask;
385         buffer = kmalloc(absize, GFP_ATOMIC);
386         if (!buffer)
387                 return -ENOMEM;
388 
389         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
390         memcpy(alignbuffer, key, keylen);
391         ret = cipher->setkey(tfm, alignbuffer, keylen);
392         memset(alignbuffer, 0, keylen);
393         kfree(buffer);
394         return ret;
395 }
396 
397 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
398 {
399         struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
400         unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
401 
402         if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
403                 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
404                 return -EINVAL;
405         }
406 
407         if ((unsigned long)key & alignmask)
408                 return setkey_unaligned(tfm, key, keylen);
409 
410         return cipher->setkey(tfm, key, keylen);
411 }
412 
413 static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
414                         unsigned int keylen)
415 {
416         return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
417 }
418 
419 static int async_encrypt(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 
430         return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
431 }
432 
433 static int async_decrypt(struct ablkcipher_request *req)
434 {
435         struct crypto_tfm *tfm = req->base.tfm;
436         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
437         struct blkcipher_desc desc = {
438                 .tfm = __crypto_blkcipher_cast(tfm),
439                 .info = req->info,
440                 .flags = req->base.flags,
441         };
442 
443         return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
444 }
445 
446 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
447                                              u32 mask)
448 {
449         struct blkcipher_alg *cipher = &alg->cra_blkcipher;
450         unsigned int len = alg->cra_ctxsize;
451 
452         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
453             cipher->ivsize) {
454                 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
455                 len += cipher->ivsize;
456         }
457 
458         return len;
459 }
460 
461 static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
462 {
463         struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
464         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
465 
466         crt->setkey = async_setkey;
467         crt->encrypt = async_encrypt;
468         crt->decrypt = async_decrypt;
469         if (!alg->ivsize) {
470                 crt->givencrypt = skcipher_null_givencrypt;
471                 crt->givdecrypt = skcipher_null_givdecrypt;
472         }
473         crt->base = __crypto_ablkcipher_cast(tfm);
474         crt->ivsize = alg->ivsize;
475 
476         return 0;
477 }
478 
479 static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
480 {
481         struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
482         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
483         unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
484         unsigned long addr;
485 
486         crt->setkey = setkey;
487         crt->encrypt = alg->encrypt;
488         crt->decrypt = alg->decrypt;
489 
490         addr = (unsigned long)crypto_tfm_ctx(tfm);
491         addr = ALIGN(addr, align);
492         addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
493         crt->iv = (void *)addr;
494 
495         return 0;
496 }
497 
498 static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
499 {
500         struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
501 
502         if (alg->ivsize > PAGE_SIZE / 8)
503                 return -EINVAL;
504 
505         if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
506                 return crypto_init_blkcipher_ops_sync(tfm);
507         else
508                 return crypto_init_blkcipher_ops_async(tfm);
509 }
510 
511 #ifdef CONFIG_NET
512 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
513 {
514         struct crypto_report_blkcipher rblkcipher;
515 
516         strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
517         strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
518                 sizeof(rblkcipher.geniv));
519 
520         rblkcipher.blocksize = alg->cra_blocksize;
521         rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
522         rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
523         rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
524 
525         if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
526                     sizeof(struct crypto_report_blkcipher), &rblkcipher))
527                 goto nla_put_failure;
528         return 0;
529 
530 nla_put_failure:
531         return -EMSGSIZE;
532 }
533 #else
534 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
535 {
536         return -ENOSYS;
537 }
538 #endif
539 
540 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
541         __attribute__ ((unused));
542 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
543 {
544         seq_printf(m, "type         : blkcipher\n");
545         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
546         seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
547         seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
548         seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
549         seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
550                                              "<default>");
551 }
552 
553 const struct crypto_type crypto_blkcipher_type = {
554         .ctxsize = crypto_blkcipher_ctxsize,
555         .init = crypto_init_blkcipher_ops,
556 #ifdef CONFIG_PROC_FS
557         .show = crypto_blkcipher_show,
558 #endif
559         .report = crypto_blkcipher_report,
560 };
561 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
562 
563 static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
564                                 const char *name, u32 type, u32 mask)
565 {
566         struct crypto_alg *alg;
567         int err;
568 
569         type = crypto_skcipher_type(type);
570         mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
571 
572         alg = crypto_alg_mod_lookup(name, type, mask);
573         if (IS_ERR(alg))
574                 return PTR_ERR(alg);
575 
576         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
577         crypto_mod_put(alg);
578         return err;
579 }
580 
581 struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
582                                              struct rtattr **tb, u32 type,
583                                              u32 mask)
584 {
585         struct {
586                 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
587                               unsigned int keylen);
588                 int (*encrypt)(struct ablkcipher_request *req);
589                 int (*decrypt)(struct ablkcipher_request *req);
590 
591                 unsigned int min_keysize;
592                 unsigned int max_keysize;
593                 unsigned int ivsize;
594 
595                 const char *geniv;
596         } balg;
597         const char *name;
598         struct crypto_skcipher_spawn *spawn;
599         struct crypto_attr_type *algt;
600         struct crypto_instance *inst;
601         struct crypto_alg *alg;
602         int err;
603 
604         algt = crypto_get_attr_type(tb);
605         if (IS_ERR(algt))
606                 return ERR_CAST(algt);
607 
608         if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
609             algt->mask)
610                 return ERR_PTR(-EINVAL);
611 
612         name = crypto_attr_alg_name(tb[1]);
613         if (IS_ERR(name))
614                 return ERR_CAST(name);
615 
616         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
617         if (!inst)
618                 return ERR_PTR(-ENOMEM);
619 
620         spawn = crypto_instance_ctx(inst);
621 
622         /* Ignore async algorithms if necessary. */
623         mask |= crypto_requires_sync(algt->type, algt->mask);
624 
625         crypto_set_skcipher_spawn(spawn, inst);
626         err = crypto_grab_nivcipher(spawn, name, type, mask);
627         if (err)
628                 goto err_free_inst;
629 
630         alg = crypto_skcipher_spawn_alg(spawn);
631 
632         if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
633             CRYPTO_ALG_TYPE_BLKCIPHER) {
634                 balg.ivsize = alg->cra_blkcipher.ivsize;
635                 balg.min_keysize = alg->cra_blkcipher.min_keysize;
636                 balg.max_keysize = alg->cra_blkcipher.max_keysize;
637 
638                 balg.setkey = async_setkey;
639                 balg.encrypt = async_encrypt;
640                 balg.decrypt = async_decrypt;
641 
642                 balg.geniv = alg->cra_blkcipher.geniv;
643         } else {
644                 balg.ivsize = alg->cra_ablkcipher.ivsize;
645                 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
646                 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
647 
648                 balg.setkey = alg->cra_ablkcipher.setkey;
649                 balg.encrypt = alg->cra_ablkcipher.encrypt;
650                 balg.decrypt = alg->cra_ablkcipher.decrypt;
651 
652                 balg.geniv = alg->cra_ablkcipher.geniv;
653         }
654 
655         err = -EINVAL;
656         if (!balg.ivsize)
657                 goto err_drop_alg;
658 
659         /*
660          * This is only true if we're constructing an algorithm with its
661          * default IV generator.  For the default generator we elide the
662          * template name and double-check the IV generator.
663          */
664         if (algt->mask & CRYPTO_ALG_GENIV) {
665                 if (!balg.geniv)
666                         balg.geniv = crypto_default_geniv(alg);
667                 err = -EAGAIN;
668                 if (strcmp(tmpl->name, balg.geniv))
669                         goto err_drop_alg;
670 
671                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
672                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
673                        CRYPTO_MAX_ALG_NAME);
674         } else {
675                 err = -ENAMETOOLONG;
676                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
677                              "%s(%s)", tmpl->name, alg->cra_name) >=
678                     CRYPTO_MAX_ALG_NAME)
679                         goto err_drop_alg;
680                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
681                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
682                     CRYPTO_MAX_ALG_NAME)
683                         goto err_drop_alg;
684         }
685 
686         inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
687         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
688         inst->alg.cra_priority = alg->cra_priority;
689         inst->alg.cra_blocksize = alg->cra_blocksize;
690         inst->alg.cra_alignmask = alg->cra_alignmask;
691         inst->alg.cra_type = &crypto_givcipher_type;
692 
693         inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
694         inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
695         inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
696         inst->alg.cra_ablkcipher.geniv = balg.geniv;
697 
698         inst->alg.cra_ablkcipher.setkey = balg.setkey;
699         inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
700         inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
701 
702 out:
703         return inst;
704 
705 err_drop_alg:
706         crypto_drop_skcipher(spawn);
707 err_free_inst:
708         kfree(inst);
709         inst = ERR_PTR(err);
710         goto out;
711 }
712 EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
713 
714 void skcipher_geniv_free(struct crypto_instance *inst)
715 {
716         crypto_drop_skcipher(crypto_instance_ctx(inst));
717         kfree(inst);
718 }
719 EXPORT_SYMBOL_GPL(skcipher_geniv_free);
720 
721 int skcipher_geniv_init(struct crypto_tfm *tfm)
722 {
723         struct crypto_instance *inst = (void *)tfm->__crt_alg;
724         struct crypto_ablkcipher *cipher;
725 
726         cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
727         if (IS_ERR(cipher))
728                 return PTR_ERR(cipher);
729 
730         tfm->crt_ablkcipher.base = cipher;
731         tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
732 
733         return 0;
734 }
735 EXPORT_SYMBOL_GPL(skcipher_geniv_init);
736 
737 void skcipher_geniv_exit(struct crypto_tfm *tfm)
738 {
739         crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
740 }
741 EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
742 
743 MODULE_LICENSE("GPL");
744 MODULE_DESCRIPTION("Generic block chaining cipher type");
745 

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