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  1/*
  2 * Asynchronous block chaining cipher operations.
  3 *
  4 * This is the asynchronous version of blkcipher.c indicating completion
  5 * via a callback.
  6 *
  7 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  8 *
  9 * This program is free software; you can redistribute it and/or modify it
 10 * under the terms of the GNU General Public License as published by the Free
 11 * Software Foundation; either version 2 of the License, or (at your option)
 12 * any later version.
 13 *
 14 */
 15
 16#include <crypto/internal/skcipher.h>
 17#include <linux/cpumask.h>
 18#include <linux/err.h>
 19#include <linux/init.h>
 20#include <linux/kernel.h>
 21#include <linux/module.h>
 22#include <linux/rtnetlink.h>
 23#include <linux/sched.h>
 24#include <linux/slab.h>
 25#include <linux/seq_file.h>
 26#include <linux/cryptouser.h>
 27#include <net/netlink.h>
 28
 29#include <crypto/scatterwalk.h>
 30
 31#include "internal.h"
 32
 33static const char *skcipher_default_geniv __read_mostly;
 34
 35struct ablkcipher_buffer {
 36	struct list_head	entry;
 37	struct scatter_walk	dst;
 38	unsigned int		len;
 39	void			*data;
 40};
 41
 42enum {
 43	ABLKCIPHER_WALK_SLOW = 1 << 0,
 44};
 45
 46static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
 47{
 48	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
 49}
 50
 51void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
 52{
 53	struct ablkcipher_buffer *p, *tmp;
 54
 55	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 56		ablkcipher_buffer_write(p);
 57		list_del(&p->entry);
 58		kfree(p);
 59	}
 60}
 61EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
 62
 63static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
 64					  struct ablkcipher_buffer *p)
 65{
 66	p->dst = walk->out;
 67	list_add_tail(&p->entry, &walk->buffers);
 68}
 69
 70/* Get a spot of the specified length that does not straddle a page.
 71 * The caller needs to ensure that there is enough space for this operation.
 72 */
 73static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
 74{
 75	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
 76	return max(start, end_page);
 77}
 78
 79static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
 80						unsigned int bsize)
 81{
 82	unsigned int n = bsize;
 83
 84	for (;;) {
 85		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
 86
 87		if (len_this_page > n)
 88			len_this_page = n;
 89		scatterwalk_advance(&walk->out, n);
 90		if (n == len_this_page)
 91			break;
 92		n -= len_this_page;
 93		scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
 94	}
 95
 96	return bsize;
 97}
 98
 99static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
100						unsigned int n)
101{
102	scatterwalk_advance(&walk->in, n);
103	scatterwalk_advance(&walk->out, n);
104
105	return n;
106}
107
108static int ablkcipher_walk_next(struct ablkcipher_request *req,
109				struct ablkcipher_walk *walk);
110
111int ablkcipher_walk_done(struct ablkcipher_request *req,
112			 struct ablkcipher_walk *walk, int err)
113{
114	struct crypto_tfm *tfm = req->base.tfm;
115	unsigned int nbytes = 0;
116
117	if (likely(err >= 0)) {
118		unsigned int n = walk->nbytes - err;
119
120		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
121			n = ablkcipher_done_fast(walk, n);
122		else if (WARN_ON(err)) {
123			err = -EINVAL;
124			goto err;
125		} else
126			n = ablkcipher_done_slow(walk, n);
127
128		nbytes = walk->total - n;
129		err = 0;
130	}
131
132	scatterwalk_done(&walk->in, 0, nbytes);
133	scatterwalk_done(&walk->out, 1, nbytes);
134
135err:
136	walk->total = nbytes;
137	walk->nbytes = nbytes;
138
139	if (nbytes) {
140		crypto_yield(req->base.flags);
141		return ablkcipher_walk_next(req, walk);
142	}
143
144	if (walk->iv != req->info)
145		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
146	kfree(walk->iv_buffer);
147
148	return err;
149}
150EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
151
152static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
153				       struct ablkcipher_walk *walk,
154				       unsigned int bsize,
155				       unsigned int alignmask,
156				       void **src_p, void **dst_p)
157{
158	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
159	struct ablkcipher_buffer *p;
160	void *src, *dst, *base;
161	unsigned int n;
162
163	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
164	n += (aligned_bsize * 3 - (alignmask + 1) +
165	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
166
167	p = kmalloc(n, GFP_ATOMIC);
168	if (!p)
169		return ablkcipher_walk_done(req, walk, -ENOMEM);
170
171	base = p + 1;
172
173	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
174	src = dst = ablkcipher_get_spot(dst, bsize);
175
176	p->len = bsize;
177	p->data = dst;
178
179	scatterwalk_copychunks(src, &walk->in, bsize, 0);
180
181	ablkcipher_queue_write(walk, p);
182
183	walk->nbytes = bsize;
184	walk->flags |= ABLKCIPHER_WALK_SLOW;
185
186	*src_p = src;
187	*dst_p = dst;
188
189	return 0;
190}
191
192static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
193				     struct crypto_tfm *tfm,
194				     unsigned int alignmask)
195{
196	unsigned bs = walk->blocksize;
197	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
198	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
199	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
200			    (alignmask + 1);
201	u8 *iv;
202
203	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
204	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
205	if (!walk->iv_buffer)
206		return -ENOMEM;
207
208	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
209	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
210	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
211	iv = ablkcipher_get_spot(iv, ivsize);
212
213	walk->iv = memcpy(iv, walk->iv, ivsize);
214	return 0;
215}
216
217static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
218				       struct ablkcipher_walk *walk)
219{
220	walk->src.page = scatterwalk_page(&walk->in);
221	walk->src.offset = offset_in_page(walk->in.offset);
222	walk->dst.page = scatterwalk_page(&walk->out);
223	walk->dst.offset = offset_in_page(walk->out.offset);
224
225	return 0;
226}
227
228static int ablkcipher_walk_next(struct ablkcipher_request *req,
229				struct ablkcipher_walk *walk)
230{
231	struct crypto_tfm *tfm = req->base.tfm;
232	unsigned int alignmask, bsize, n;
233	void *src, *dst;
234	int err;
235
236	alignmask = crypto_tfm_alg_alignmask(tfm);
237	n = walk->total;
238	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
239		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
240		return ablkcipher_walk_done(req, walk, -EINVAL);
241	}
242
243	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
244	src = dst = NULL;
245
246	bsize = min(walk->blocksize, n);
247	n = scatterwalk_clamp(&walk->in, n);
248	n = scatterwalk_clamp(&walk->out, n);
249
250	if (n < bsize ||
251	    !scatterwalk_aligned(&walk->in, alignmask) ||
252	    !scatterwalk_aligned(&walk->out, alignmask)) {
253		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
254					   &src, &dst);
255		goto set_phys_lowmem;
256	}
257
258	walk->nbytes = n;
259
260	return ablkcipher_next_fast(req, walk);
261
262set_phys_lowmem:
263	if (err >= 0) {
264		walk->src.page = virt_to_page(src);
265		walk->dst.page = virt_to_page(dst);
266		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
267		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
268	}
269
270	return err;
271}
272
273static int ablkcipher_walk_first(struct ablkcipher_request *req,
274				 struct ablkcipher_walk *walk)
275{
276	struct crypto_tfm *tfm = req->base.tfm;
277	unsigned int alignmask;
278
279	alignmask = crypto_tfm_alg_alignmask(tfm);
280	if (WARN_ON_ONCE(in_irq()))
281		return -EDEADLK;
282
283	walk->nbytes = walk->total;
284	if (unlikely(!walk->total))
285		return 0;
286
287	walk->iv_buffer = NULL;
288	walk->iv = req->info;
289	if (unlikely(((unsigned long)walk->iv & alignmask))) {
290		int err = ablkcipher_copy_iv(walk, tfm, alignmask);
291		if (err)
292			return err;
293	}
294
295	scatterwalk_start(&walk->in, walk->in.sg);
296	scatterwalk_start(&walk->out, walk->out.sg);
297
298	return ablkcipher_walk_next(req, walk);
299}
300
301int ablkcipher_walk_phys(struct ablkcipher_request *req,
302			 struct ablkcipher_walk *walk)
303{
304	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
305	return ablkcipher_walk_first(req, walk);
306}
307EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
308
309static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
310			    unsigned int keylen)
311{
312	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
313	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
314	int ret;
315	u8 *buffer, *alignbuffer;
316	unsigned long absize;
317
318	absize = keylen + alignmask;
319	buffer = kmalloc(absize, GFP_ATOMIC);
320	if (!buffer)
321		return -ENOMEM;
322
323	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
324	memcpy(alignbuffer, key, keylen);
325	ret = cipher->setkey(tfm, alignbuffer, keylen);
326	memset(alignbuffer, 0, keylen);
327	kfree(buffer);
328	return ret;
329}
330
331static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
332		  unsigned int keylen)
333{
334	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
335	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
336
337	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
338		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
339		return -EINVAL;
340	}
341
342	if ((unsigned long)key & alignmask)
343		return setkey_unaligned(tfm, key, keylen);
344
345	return cipher->setkey(tfm, key, keylen);
346}
347
348static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
349					      u32 mask)
350{
351	return alg->cra_ctxsize;
352}
353
354int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
355{
356	return crypto_ablkcipher_encrypt(&req->creq);
357}
358
359int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
360{
361	return crypto_ablkcipher_decrypt(&req->creq);
362}
363
364static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
365				      u32 mask)
366{
367	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
368	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
369
370	if (alg->ivsize > PAGE_SIZE / 8)
371		return -EINVAL;
372
373	crt->setkey = setkey;
374	crt->encrypt = alg->encrypt;
375	crt->decrypt = alg->decrypt;
376	if (!alg->ivsize) {
377		crt->givencrypt = skcipher_null_givencrypt;
378		crt->givdecrypt = skcipher_null_givdecrypt;
379	}
380	crt->base = __crypto_ablkcipher_cast(tfm);
381	crt->ivsize = alg->ivsize;
382
383	return 0;
384}
385
386#ifdef CONFIG_NET
387static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
388{
389	struct crypto_report_blkcipher rblkcipher;
390
391	snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "ablkcipher");
392	snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
393		 alg->cra_ablkcipher.geniv ?: "<default>");
394
395	rblkcipher.blocksize = alg->cra_blocksize;
396	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
397	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
398	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
399
400	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
401		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
402		goto nla_put_failure;
403	return 0;
404
405nla_put_failure:
406	return -EMSGSIZE;
407}
408#else
409static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
410{
411	return -ENOSYS;
412}
413#endif
414
415static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
416	__attribute__ ((unused));
417static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
418{
419	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
420
421	seq_printf(m, "type         : ablkcipher\n");
422	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
423					     "yes" : "no");
424	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
425	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
426	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
427	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
428	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
429}
430
431const struct crypto_type crypto_ablkcipher_type = {
432	.ctxsize = crypto_ablkcipher_ctxsize,
433	.init = crypto_init_ablkcipher_ops,
434#ifdef CONFIG_PROC_FS
435	.show = crypto_ablkcipher_show,
436#endif
437	.report = crypto_ablkcipher_report,
438};
439EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
440
441static int no_givdecrypt(struct skcipher_givcrypt_request *req)
442{
443	return -ENOSYS;
444}
445
446static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
447				      u32 mask)
448{
449	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
450	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
451
452	if (alg->ivsize > PAGE_SIZE / 8)
453		return -EINVAL;
454
455	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
456		      alg->setkey : setkey;
457	crt->encrypt = alg->encrypt;
458	crt->decrypt = alg->decrypt;
459	crt->givencrypt = alg->givencrypt;
460	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
461	crt->base = __crypto_ablkcipher_cast(tfm);
462	crt->ivsize = alg->ivsize;
463
464	return 0;
465}
466
467#ifdef CONFIG_NET
468static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
469{
470	struct crypto_report_blkcipher rblkcipher;
471
472	snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "givcipher");
473	snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
474		 alg->cra_ablkcipher.geniv ?: "<built-in>");
475
476	rblkcipher.blocksize = alg->cra_blocksize;
477	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
478	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
479	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
480
481	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
482		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
483		goto nla_put_failure;
484	return 0;
485
486nla_put_failure:
487	return -EMSGSIZE;
488}
489#else
490static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
491{
492	return -ENOSYS;
493}
494#endif
495
496static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
497	__attribute__ ((unused));
498static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
499{
500	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
501
502	seq_printf(m, "type         : givcipher\n");
503	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
504					     "yes" : "no");
505	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
506	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
507	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
508	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
509	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
510}
511
512const struct crypto_type crypto_givcipher_type = {
513	.ctxsize = crypto_ablkcipher_ctxsize,
514	.init = crypto_init_givcipher_ops,
515#ifdef CONFIG_PROC_FS
516	.show = crypto_givcipher_show,
517#endif
518	.report = crypto_givcipher_report,
519};
520EXPORT_SYMBOL_GPL(crypto_givcipher_type);
521
522const char *crypto_default_geniv(const struct crypto_alg *alg)
523{
524	if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
525	     CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
526					 alg->cra_ablkcipher.ivsize) !=
527	    alg->cra_blocksize)
528		return "chainiv";
529
530	return alg->cra_flags & CRYPTO_ALG_ASYNC ?
531	       "eseqiv" : skcipher_default_geniv;
532}
533
534static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
535{
536	struct rtattr *tb[3];
537	struct {
538		struct rtattr attr;
539		struct crypto_attr_type data;
540	} ptype;
541	struct {
542		struct rtattr attr;
543		struct crypto_attr_alg data;
544	} palg;
545	struct crypto_template *tmpl;
546	struct crypto_instance *inst;
547	struct crypto_alg *larval;
548	const char *geniv;
549	int err;
550
551	larval = crypto_larval_lookup(alg->cra_driver_name,
552				      (type & ~CRYPTO_ALG_TYPE_MASK) |
553				      CRYPTO_ALG_TYPE_GIVCIPHER,
554				      mask | CRYPTO_ALG_TYPE_MASK);
555	err = PTR_ERR(larval);
556	if (IS_ERR(larval))
557		goto out;
558
559	err = -EAGAIN;
560	if (!crypto_is_larval(larval))
561		goto drop_larval;
562
563	ptype.attr.rta_len = sizeof(ptype);
564	ptype.attr.rta_type = CRYPTOA_TYPE;
565	ptype.data.type = type | CRYPTO_ALG_GENIV;
566	/* GENIV tells the template that we're making a default geniv. */
567	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
568	tb[0] = &ptype.attr;
569
570	palg.attr.rta_len = sizeof(palg);
571	palg.attr.rta_type = CRYPTOA_ALG;
572	/* Must use the exact name to locate ourselves. */
573	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
574	tb[1] = &palg.attr;
575
576	tb[2] = NULL;
577
578	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
579	    CRYPTO_ALG_TYPE_BLKCIPHER)
580		geniv = alg->cra_blkcipher.geniv;
581	else
582		geniv = alg->cra_ablkcipher.geniv;
583
584	if (!geniv)
585		geniv = crypto_default_geniv(alg);
586
587	tmpl = crypto_lookup_template(geniv);
588	err = -ENOENT;
589	if (!tmpl)
590		goto kill_larval;
591
592	inst = tmpl->alloc(tb);
593	err = PTR_ERR(inst);
594	if (IS_ERR(inst))
595		goto put_tmpl;
596
597	if ((err = crypto_register_instance(tmpl, inst))) {
598		tmpl->free(inst);
599		goto put_tmpl;
600	}
601
602	/* Redo the lookup to use the instance we just registered. */
603	err = -EAGAIN;
604
605put_tmpl:
606	crypto_tmpl_put(tmpl);
607kill_larval:
608	crypto_larval_kill(larval);
609drop_larval:
610	crypto_mod_put(larval);
611out:
612	crypto_mod_put(alg);
613	return err;
614}
615
616struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
617{
618	struct crypto_alg *alg;
619
620	alg = crypto_alg_mod_lookup(name, type, mask);
621	if (IS_ERR(alg))
622		return alg;
623
624	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
625	    CRYPTO_ALG_TYPE_GIVCIPHER)
626		return alg;
627
628	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
629	      CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
630					  alg->cra_ablkcipher.ivsize))
631		return alg;
632
633	crypto_mod_put(alg);
634	alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
635				    mask & ~CRYPTO_ALG_TESTED);
636	if (IS_ERR(alg))
637		return alg;
638
639	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
640	    CRYPTO_ALG_TYPE_GIVCIPHER) {
641		if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
642			crypto_mod_put(alg);
643			alg = ERR_PTR(-ENOENT);
644		}
645		return alg;
646	}
647
648	BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
649		 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
650					     alg->cra_ablkcipher.ivsize));
651
652	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
653}
654EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
655
656int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
657			 u32 type, u32 mask)
658{
659	struct crypto_alg *alg;
660	int err;
661
662	type = crypto_skcipher_type(type);
663	mask = crypto_skcipher_mask(mask);
664
665	alg = crypto_lookup_skcipher(name, type, mask);
666	if (IS_ERR(alg))
667		return PTR_ERR(alg);
668
669	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
670	crypto_mod_put(alg);
671	return err;
672}
673EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
674
675struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
676						  u32 type, u32 mask)
677{
678	struct crypto_tfm *tfm;
679	int err;
680
681	type = crypto_skcipher_type(type);
682	mask = crypto_skcipher_mask(mask);
683
684	for (;;) {
685		struct crypto_alg *alg;
686
687		alg = crypto_lookup_skcipher(alg_name, type, mask);
688		if (IS_ERR(alg)) {
689			err = PTR_ERR(alg);
690			goto err;
691		}
692
693		tfm = __crypto_alloc_tfm(alg, type, mask);
694		if (!IS_ERR(tfm))
695			return __crypto_ablkcipher_cast(tfm);
696
697		crypto_mod_put(alg);
698		err = PTR_ERR(tfm);
699
700err:
701		if (err != -EAGAIN)
702			break;
703		if (signal_pending(current)) {
704			err = -EINTR;
705			break;
706		}
707	}
708
709	return ERR_PTR(err);
710}
711EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
712
713static int __init skcipher_module_init(void)
714{
715	skcipher_default_geniv = num_possible_cpus() > 1 ?
716				 "eseqiv" : "chainiv";
717	return 0;
718}
719
720static void skcipher_module_exit(void)
721{
722}
723
724module_init(skcipher_module_init);
725module_exit(skcipher_module_exit);