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
blkcipher_map_src(struct blkcipher_walk * walk)44 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
45 {
46 walk->src.virt.addr = scatterwalk_map(&walk->in);
47 }
48
blkcipher_map_dst(struct blkcipher_walk * walk)49 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
50 {
51 walk->dst.virt.addr = scatterwalk_map(&walk->out);
52 }
53
blkcipher_unmap_src(struct blkcipher_walk * walk)54 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
55 {
56 scatterwalk_unmap(walk->src.virt.addr);
57 }
58
blkcipher_unmap_dst(struct blkcipher_walk * walk)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 */
blkcipher_get_spot(u8 * start,unsigned int len)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
blkcipher_done_slow(struct blkcipher_walk * walk,unsigned int bsize)73 static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
74 unsigned int bsize)
75 {
76 u8 *addr;
77
78 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
79 addr = blkcipher_get_spot(addr, bsize);
80 scatterwalk_copychunks(addr, &walk->out, bsize, 1);
81 return bsize;
82 }
83
blkcipher_done_fast(struct blkcipher_walk * walk,unsigned int n)84 static inline unsigned int 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 return n;
101 }
102
blkcipher_walk_done(struct blkcipher_desc * desc,struct blkcipher_walk * walk,int err)103 int blkcipher_walk_done(struct blkcipher_desc *desc,
104 struct blkcipher_walk *walk, int err)
105 {
106 unsigned int nbytes = 0;
107
108 if (likely(err >= 0)) {
109 unsigned int n = walk->nbytes - err;
110
111 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
112 n = blkcipher_done_fast(walk, n);
113 else if (WARN_ON(err)) {
114 err = -EINVAL;
115 goto err;
116 } else
117 n = blkcipher_done_slow(walk, n);
118
119 nbytes = walk->total - n;
120 err = 0;
121 }
122
123 scatterwalk_done(&walk->in, 0, nbytes);
124 scatterwalk_done(&walk->out, 1, nbytes);
125
126 err:
127 walk->total = nbytes;
128 walk->nbytes = nbytes;
129
130 if (nbytes) {
131 crypto_yield(desc->flags);
132 return blkcipher_walk_next(desc, walk);
133 }
134
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
142 return err;
143 }
144 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
145
blkcipher_next_slow(struct blkcipher_desc * desc,struct blkcipher_walk * walk,unsigned int bsize,unsigned int alignmask)146 static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
147 struct blkcipher_walk *walk,
148 unsigned int bsize,
149 unsigned int alignmask)
150 {
151 unsigned int n;
152 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
153
154 if (walk->buffer)
155 goto ok;
156
157 walk->buffer = walk->page;
158 if (walk->buffer)
159 goto ok;
160
161 n = aligned_bsize * 3 - (alignmask + 1) +
162 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
163 walk->buffer = kmalloc(n, GFP_ATOMIC);
164 if (!walk->buffer)
165 return blkcipher_walk_done(desc, walk, -ENOMEM);
166
167 ok:
168 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
169 alignmask + 1);
170 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
171 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
172 aligned_bsize, bsize);
173
174 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
175
176 walk->nbytes = bsize;
177 walk->flags |= BLKCIPHER_WALK_SLOW;
178
179 return 0;
180 }
181
blkcipher_next_copy(struct blkcipher_walk * walk)182 static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
183 {
184 u8 *tmp = walk->page;
185
186 blkcipher_map_src(walk);
187 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
188 blkcipher_unmap_src(walk);
189
190 walk->src.virt.addr = tmp;
191 walk->dst.virt.addr = tmp;
192
193 return 0;
194 }
195
blkcipher_next_fast(struct blkcipher_desc * desc,struct blkcipher_walk * walk)196 static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
197 struct blkcipher_walk *walk)
198 {
199 unsigned long diff;
200
201 walk->src.phys.page = scatterwalk_page(&walk->in);
202 walk->src.phys.offset = offset_in_page(walk->in.offset);
203 walk->dst.phys.page = scatterwalk_page(&walk->out);
204 walk->dst.phys.offset = offset_in_page(walk->out.offset);
205
206 if (walk->flags & BLKCIPHER_WALK_PHYS)
207 return 0;
208
209 diff = walk->src.phys.offset - walk->dst.phys.offset;
210 diff |= walk->src.virt.page - walk->dst.virt.page;
211
212 blkcipher_map_src(walk);
213 walk->dst.virt.addr = walk->src.virt.addr;
214
215 if (diff) {
216 walk->flags |= BLKCIPHER_WALK_DIFF;
217 blkcipher_map_dst(walk);
218 }
219
220 return 0;
221 }
222
blkcipher_walk_next(struct blkcipher_desc * desc,struct blkcipher_walk * walk)223 static int blkcipher_walk_next(struct blkcipher_desc *desc,
224 struct blkcipher_walk *walk)
225 {
226 unsigned int bsize;
227 unsigned int n;
228 int err;
229
230 n = walk->total;
231 if (unlikely(n < walk->cipher_blocksize)) {
232 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
233 return blkcipher_walk_done(desc, walk, -EINVAL);
234 }
235
236 bsize = min(walk->walk_blocksize, n);
237
238 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
239 BLKCIPHER_WALK_DIFF);
240 if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
241 !scatterwalk_aligned(&walk->out, walk->alignmask)) {
242 walk->flags |= BLKCIPHER_WALK_COPY;
243 if (!walk->page) {
244 walk->page = (void *)__get_free_page(GFP_ATOMIC);
245 if (!walk->page)
246 n = 0;
247 }
248 }
249
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
blkcipher_copy_iv(struct blkcipher_walk * walk)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
blkcipher_walk_virt(struct blkcipher_desc * desc,struct blkcipher_walk * walk)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
blkcipher_walk_phys(struct blkcipher_desc * desc,struct blkcipher_walk * walk)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
blkcipher_walk_first(struct blkcipher_desc * desc,struct blkcipher_walk * walk)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->nbytes = walk->total;
330 if (unlikely(!walk->total))
331 return 0;
332
333 walk->buffer = NULL;
334 walk->iv = desc->info;
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
blkcipher_walk_virt_block(struct blkcipher_desc * desc,struct blkcipher_walk * walk,unsigned int blocksize)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
blkcipher_aead_walk_virt_block(struct blkcipher_desc * desc,struct blkcipher_walk * walk,struct crypto_aead * tfm,unsigned int blocksize)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
setkey_unaligned(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)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
setkey(struct crypto_tfm * tfm,const u8 * key,unsigned int keylen)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
async_setkey(struct crypto_ablkcipher * tfm,const u8 * key,unsigned int keylen)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
async_encrypt(struct ablkcipher_request * req)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
async_decrypt(struct ablkcipher_request * req)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
crypto_blkcipher_ctxsize(struct crypto_alg * alg,u32 type,u32 mask)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
crypto_init_blkcipher_ops_async(struct crypto_tfm * tfm)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
crypto_init_blkcipher_ops_sync(struct crypto_tfm * tfm)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
crypto_init_blkcipher_ops(struct crypto_tfm * tfm,u32 type,u32 mask)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
crypto_blkcipher_report(struct sk_buff * skb,struct crypto_alg * alg)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
crypto_blkcipher_report(struct sk_buff * skb,struct crypto_alg * alg)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));
crypto_blkcipher_show(struct seq_file * m,struct crypto_alg * alg)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
crypto_grab_nivcipher(struct crypto_skcipher_spawn * spawn,const char * name,u32 type,u32 mask)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
skcipher_geniv_alloc(struct crypto_template * tmpl,struct rtattr ** tb,u32 type,u32 mask)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
skcipher_geniv_free(struct crypto_instance * inst)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
skcipher_geniv_init(struct crypto_tfm * tfm)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
skcipher_geniv_exit(struct crypto_tfm * tfm)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