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v4.6
  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/kernel.h>
 
 20#include <linux/rtnetlink.h>
 21#include <linux/sched.h>
 22#include <linux/slab.h>
 23#include <linux/seq_file.h>
 24#include <linux/cryptouser.h>
 25#include <net/netlink.h>
 26
 27#include <crypto/scatterwalk.h>
 28
 29#include "internal.h"
 30
 
 
 31struct ablkcipher_buffer {
 32	struct list_head	entry;
 33	struct scatter_walk	dst;
 34	unsigned int		len;
 35	void			*data;
 36};
 37
 38enum {
 39	ABLKCIPHER_WALK_SLOW = 1 << 0,
 40};
 41
 42static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
 43{
 44	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
 45}
 46
 47void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
 48{
 49	struct ablkcipher_buffer *p, *tmp;
 50
 51	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 52		ablkcipher_buffer_write(p);
 53		list_del(&p->entry);
 54		kfree(p);
 55	}
 56}
 57EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
 58
 59static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
 60					  struct ablkcipher_buffer *p)
 61{
 62	p->dst = walk->out;
 63	list_add_tail(&p->entry, &walk->buffers);
 64}
 65
 66/* Get a spot of the specified length that does not straddle a page.
 67 * The caller needs to ensure that there is enough space for this operation.
 68 */
 69static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
 70{
 71	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
 72
 73	return max(start, end_page);
 74}
 75
 76static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
 77						unsigned int bsize)
 78{
 79	unsigned int n = bsize;
 80
 81	for (;;) {
 82		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
 83
 84		if (len_this_page > n)
 85			len_this_page = n;
 86		scatterwalk_advance(&walk->out, n);
 87		if (n == len_this_page)
 88			break;
 89		n -= len_this_page;
 90		scatterwalk_start(&walk->out, sg_next(walk->out.sg));
 91	}
 92
 93	return bsize;
 94}
 95
 96static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
 97						unsigned int n)
 98{
 99	scatterwalk_advance(&walk->in, n);
100	scatterwalk_advance(&walk->out, n);
101
102	return n;
103}
104
105static int ablkcipher_walk_next(struct ablkcipher_request *req,
106				struct ablkcipher_walk *walk);
107
108int ablkcipher_walk_done(struct ablkcipher_request *req,
109			 struct ablkcipher_walk *walk, int err)
110{
111	struct crypto_tfm *tfm = req->base.tfm;
112	unsigned int nbytes = 0;
113
114	if (likely(err >= 0)) {
115		unsigned int n = walk->nbytes - err;
116
117		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
118			n = ablkcipher_done_fast(walk, n);
119		else if (WARN_ON(err)) {
120			err = -EINVAL;
121			goto err;
122		} else
123			n = ablkcipher_done_slow(walk, n);
124
125		nbytes = walk->total - n;
126		err = 0;
127	}
128
129	scatterwalk_done(&walk->in, 0, nbytes);
130	scatterwalk_done(&walk->out, 1, nbytes);
131
132err:
133	walk->total = nbytes;
134	walk->nbytes = nbytes;
135
136	if (nbytes) {
137		crypto_yield(req->base.flags);
138		return ablkcipher_walk_next(req, walk);
139	}
140
141	if (walk->iv != req->info)
142		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
143	kfree(walk->iv_buffer);
144
145	return err;
146}
147EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
148
149static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
150				       struct ablkcipher_walk *walk,
151				       unsigned int bsize,
152				       unsigned int alignmask,
153				       void **src_p, void **dst_p)
154{
155	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
156	struct ablkcipher_buffer *p;
157	void *src, *dst, *base;
158	unsigned int n;
159
160	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
161	n += (aligned_bsize * 3 - (alignmask + 1) +
162	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
163
164	p = kmalloc(n, GFP_ATOMIC);
165	if (!p)
166		return ablkcipher_walk_done(req, walk, -ENOMEM);
167
168	base = p + 1;
169
170	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
171	src = dst = ablkcipher_get_spot(dst, bsize);
172
173	p->len = bsize;
174	p->data = dst;
175
176	scatterwalk_copychunks(src, &walk->in, bsize, 0);
177
178	ablkcipher_queue_write(walk, p);
179
180	walk->nbytes = bsize;
181	walk->flags |= ABLKCIPHER_WALK_SLOW;
182
183	*src_p = src;
184	*dst_p = dst;
185
186	return 0;
187}
188
189static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
190				     struct crypto_tfm *tfm,
191				     unsigned int alignmask)
192{
193	unsigned bs = walk->blocksize;
194	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
195	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
196	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
197			    (alignmask + 1);
198	u8 *iv;
199
200	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
201	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
202	if (!walk->iv_buffer)
203		return -ENOMEM;
204
205	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
206	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
207	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
208	iv = ablkcipher_get_spot(iv, ivsize);
209
210	walk->iv = memcpy(iv, walk->iv, ivsize);
211	return 0;
212}
213
214static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
215				       struct ablkcipher_walk *walk)
216{
217	walk->src.page = scatterwalk_page(&walk->in);
218	walk->src.offset = offset_in_page(walk->in.offset);
219	walk->dst.page = scatterwalk_page(&walk->out);
220	walk->dst.offset = offset_in_page(walk->out.offset);
221
222	return 0;
223}
224
225static int ablkcipher_walk_next(struct ablkcipher_request *req,
226				struct ablkcipher_walk *walk)
227{
228	struct crypto_tfm *tfm = req->base.tfm;
229	unsigned int alignmask, bsize, n;
230	void *src, *dst;
231	int err;
232
233	alignmask = crypto_tfm_alg_alignmask(tfm);
234	n = walk->total;
235	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
236		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
237		return ablkcipher_walk_done(req, walk, -EINVAL);
238	}
239
240	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
241	src = dst = NULL;
242
243	bsize = min(walk->blocksize, n);
244	n = scatterwalk_clamp(&walk->in, n);
245	n = scatterwalk_clamp(&walk->out, n);
246
247	if (n < bsize ||
248	    !scatterwalk_aligned(&walk->in, alignmask) ||
249	    !scatterwalk_aligned(&walk->out, alignmask)) {
250		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
251					   &src, &dst);
252		goto set_phys_lowmem;
253	}
254
255	walk->nbytes = n;
256
257	return ablkcipher_next_fast(req, walk);
258
259set_phys_lowmem:
260	if (err >= 0) {
261		walk->src.page = virt_to_page(src);
262		walk->dst.page = virt_to_page(dst);
263		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
264		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
265	}
266
267	return err;
268}
269
270static int ablkcipher_walk_first(struct ablkcipher_request *req,
271				 struct ablkcipher_walk *walk)
272{
273	struct crypto_tfm *tfm = req->base.tfm;
274	unsigned int alignmask;
275
276	alignmask = crypto_tfm_alg_alignmask(tfm);
277	if (WARN_ON_ONCE(in_irq()))
278		return -EDEADLK;
279
280	walk->iv = req->info;
281	walk->nbytes = walk->total;
282	if (unlikely(!walk->total))
283		return 0;
284
285	walk->iv_buffer = NULL;
 
286	if (unlikely(((unsigned long)walk->iv & alignmask))) {
287		int err = ablkcipher_copy_iv(walk, tfm, alignmask);
288
289		if (err)
290			return err;
291	}
292
293	scatterwalk_start(&walk->in, walk->in.sg);
294	scatterwalk_start(&walk->out, walk->out.sg);
295
296	return ablkcipher_walk_next(req, walk);
297}
298
299int ablkcipher_walk_phys(struct ablkcipher_request *req,
300			 struct ablkcipher_walk *walk)
301{
302	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
303	return ablkcipher_walk_first(req, walk);
304}
305EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
306
307static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
308			    unsigned int keylen)
309{
310	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
311	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
312	int ret;
313	u8 *buffer, *alignbuffer;
314	unsigned long absize;
315
316	absize = keylen + alignmask;
317	buffer = kmalloc(absize, GFP_ATOMIC);
318	if (!buffer)
319		return -ENOMEM;
320
321	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
322	memcpy(alignbuffer, key, keylen);
323	ret = cipher->setkey(tfm, alignbuffer, keylen);
324	memset(alignbuffer, 0, keylen);
325	kfree(buffer);
326	return ret;
327}
328
329static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
330		  unsigned int keylen)
331{
332	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
333	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
334
335	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
336		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
337		return -EINVAL;
338	}
339
340	if ((unsigned long)key & alignmask)
341		return setkey_unaligned(tfm, key, keylen);
342
343	return cipher->setkey(tfm, key, keylen);
344}
345
346static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
347					      u32 mask)
348{
349	return alg->cra_ctxsize;
350}
351
352int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
353{
354	return crypto_ablkcipher_encrypt(&req->creq);
355}
356
357int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
358{
359	return crypto_ablkcipher_decrypt(&req->creq);
360}
361
362static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
363				      u32 mask)
364{
365	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
366	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
367
368	if (alg->ivsize > PAGE_SIZE / 8)
369		return -EINVAL;
370
371	crt->setkey = setkey;
372	crt->encrypt = alg->encrypt;
373	crt->decrypt = alg->decrypt;
374	if (!alg->ivsize) {
375		crt->givencrypt = skcipher_null_givencrypt;
376		crt->givdecrypt = skcipher_null_givdecrypt;
377	}
378	crt->base = __crypto_ablkcipher_cast(tfm);
379	crt->ivsize = alg->ivsize;
380
381	return 0;
382}
383
384#ifdef CONFIG_NET
385static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
386{
387	struct crypto_report_blkcipher rblkcipher;
388
389	strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
390	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
391		sizeof(rblkcipher.geniv));
392
393	rblkcipher.blocksize = alg->cra_blocksize;
394	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
395	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
396	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
397
398	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
399		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
400		goto nla_put_failure;
401	return 0;
402
403nla_put_failure:
404	return -EMSGSIZE;
405}
406#else
407static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
408{
409	return -ENOSYS;
410}
411#endif
412
413static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
414	__attribute__ ((unused));
415static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
416{
417	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
418
419	seq_printf(m, "type         : ablkcipher\n");
420	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
421					     "yes" : "no");
422	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
423	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
424	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
425	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
426	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
427}
428
429const struct crypto_type crypto_ablkcipher_type = {
430	.ctxsize = crypto_ablkcipher_ctxsize,
431	.init = crypto_init_ablkcipher_ops,
432#ifdef CONFIG_PROC_FS
433	.show = crypto_ablkcipher_show,
434#endif
435	.report = crypto_ablkcipher_report,
436};
437EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
438
439static int no_givdecrypt(struct skcipher_givcrypt_request *req)
440{
441	return -ENOSYS;
442}
443
444static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
445				      u32 mask)
446{
447	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
448	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
449
450	if (alg->ivsize > PAGE_SIZE / 8)
451		return -EINVAL;
452
453	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
454		      alg->setkey : setkey;
455	crt->encrypt = alg->encrypt;
456	crt->decrypt = alg->decrypt;
457	crt->givencrypt = alg->givencrypt ?: no_givdecrypt;
458	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
459	crt->base = __crypto_ablkcipher_cast(tfm);
460	crt->ivsize = alg->ivsize;
461
462	return 0;
463}
464
465#ifdef CONFIG_NET
466static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
467{
468	struct crypto_report_blkcipher rblkcipher;
469
470	strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
471	strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
472		sizeof(rblkcipher.geniv));
473
474	rblkcipher.blocksize = alg->cra_blocksize;
475	rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
476	rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
477	rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
478
479	if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
480		    sizeof(struct crypto_report_blkcipher), &rblkcipher))
481		goto nla_put_failure;
482	return 0;
483
484nla_put_failure:
485	return -EMSGSIZE;
486}
487#else
488static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
489{
490	return -ENOSYS;
491}
492#endif
493
494static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
495	__attribute__ ((unused));
496static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
497{
498	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
499
500	seq_printf(m, "type         : givcipher\n");
501	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
502					     "yes" : "no");
503	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
504	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
505	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
506	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
507	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
508}
509
510const struct crypto_type crypto_givcipher_type = {
511	.ctxsize = crypto_ablkcipher_ctxsize,
512	.init = crypto_init_givcipher_ops,
513#ifdef CONFIG_PROC_FS
514	.show = crypto_givcipher_show,
515#endif
516	.report = crypto_givcipher_report,
517};
518EXPORT_SYMBOL_GPL(crypto_givcipher_type);
519
520const char *crypto_default_geniv(const struct crypto_alg *alg)
521{
522	if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
523	     CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
524					 alg->cra_ablkcipher.ivsize) !=
525	    alg->cra_blocksize)
526		return "chainiv";
527
528	return "eseqiv";
 
529}
530
531static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
532{
533	struct rtattr *tb[3];
534	struct {
535		struct rtattr attr;
536		struct crypto_attr_type data;
537	} ptype;
538	struct {
539		struct rtattr attr;
540		struct crypto_attr_alg data;
541	} palg;
542	struct crypto_template *tmpl;
543	struct crypto_instance *inst;
544	struct crypto_alg *larval;
545	const char *geniv;
546	int err;
547
548	larval = crypto_larval_lookup(alg->cra_driver_name,
549				      (type & ~CRYPTO_ALG_TYPE_MASK) |
550				      CRYPTO_ALG_TYPE_GIVCIPHER,
551				      mask | CRYPTO_ALG_TYPE_MASK);
552	err = PTR_ERR(larval);
553	if (IS_ERR(larval))
554		goto out;
555
556	err = -EAGAIN;
557	if (!crypto_is_larval(larval))
558		goto drop_larval;
559
560	ptype.attr.rta_len = sizeof(ptype);
561	ptype.attr.rta_type = CRYPTOA_TYPE;
562	ptype.data.type = type | CRYPTO_ALG_GENIV;
563	/* GENIV tells the template that we're making a default geniv. */
564	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
565	tb[0] = &ptype.attr;
566
567	palg.attr.rta_len = sizeof(palg);
568	palg.attr.rta_type = CRYPTOA_ALG;
569	/* Must use the exact name to locate ourselves. */
570	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
571	tb[1] = &palg.attr;
572
573	tb[2] = NULL;
574
575	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
576	    CRYPTO_ALG_TYPE_BLKCIPHER)
577		geniv = alg->cra_blkcipher.geniv;
578	else
579		geniv = alg->cra_ablkcipher.geniv;
580
581	if (!geniv)
582		geniv = crypto_default_geniv(alg);
583
584	tmpl = crypto_lookup_template(geniv);
585	err = -ENOENT;
586	if (!tmpl)
587		goto kill_larval;
588
589	if (tmpl->create) {
590		err = tmpl->create(tmpl, tb);
591		if (err)
592			goto put_tmpl;
593		goto ok;
594	}
595
596	inst = tmpl->alloc(tb);
597	err = PTR_ERR(inst);
598	if (IS_ERR(inst))
599		goto put_tmpl;
600
601	err = crypto_register_instance(tmpl, inst);
602	if (err) {
603		tmpl->free(inst);
604		goto put_tmpl;
605	}
606
607ok:
608	/* Redo the lookup to use the instance we just registered. */
609	err = -EAGAIN;
610
611put_tmpl:
612	crypto_tmpl_put(tmpl);
613kill_larval:
614	crypto_larval_kill(larval);
615drop_larval:
616	crypto_mod_put(larval);
617out:
618	crypto_mod_put(alg);
619	return err;
620}
621
622struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
 
623{
624	struct crypto_alg *alg;
625
626	alg = crypto_alg_mod_lookup(name, type, mask);
627	if (IS_ERR(alg))
628		return alg;
629
630	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
631	    CRYPTO_ALG_TYPE_GIVCIPHER)
632		return alg;
633
634	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
635	      CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
636					  alg->cra_ablkcipher.ivsize))
637		return alg;
638
639	crypto_mod_put(alg);
640	alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
641				    mask & ~CRYPTO_ALG_TESTED);
642	if (IS_ERR(alg))
643		return alg;
644
645	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
646	    CRYPTO_ALG_TYPE_GIVCIPHER) {
647		if (~alg->cra_flags & (type ^ ~mask) & CRYPTO_ALG_TESTED) {
648			crypto_mod_put(alg);
649			alg = ERR_PTR(-ENOENT);
650		}
651		return alg;
652	}
653
654	BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
655		 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
656					     alg->cra_ablkcipher.ivsize));
657
658	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
659}
660EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
661
662int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
663			 u32 type, u32 mask)
664{
665	struct crypto_alg *alg;
666	int err;
667
668	type = crypto_skcipher_type(type);
669	mask = crypto_skcipher_mask(mask);
670
671	alg = crypto_lookup_skcipher(name, type, mask);
672	if (IS_ERR(alg))
673		return PTR_ERR(alg);
674
675	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
676	crypto_mod_put(alg);
677	return err;
678}
679EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
680
681struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
682						  u32 type, u32 mask)
683{
684	struct crypto_tfm *tfm;
685	int err;
686
687	type = crypto_skcipher_type(type);
688	mask = crypto_skcipher_mask(mask);
689
690	for (;;) {
691		struct crypto_alg *alg;
692
693		alg = crypto_lookup_skcipher(alg_name, type, mask);
694		if (IS_ERR(alg)) {
695			err = PTR_ERR(alg);
696			goto err;
697		}
698
699		tfm = __crypto_alloc_tfm(alg, type, mask);
700		if (!IS_ERR(tfm))
701			return __crypto_ablkcipher_cast(tfm);
702
703		crypto_mod_put(alg);
704		err = PTR_ERR(tfm);
705
706err:
707		if (err != -EAGAIN)
708			break;
709		if (fatal_signal_pending(current)) {
710			err = -EINTR;
711			break;
712		}
713	}
714
715	return ERR_PTR(err);
716}
717EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
v3.1
  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
 27#include <crypto/scatterwalk.h>
 28
 29#include "internal.h"
 30
 31static const char *skcipher_default_geniv __read_mostly;
 32
 33struct ablkcipher_buffer {
 34	struct list_head	entry;
 35	struct scatter_walk	dst;
 36	unsigned int		len;
 37	void			*data;
 38};
 39
 40enum {
 41	ABLKCIPHER_WALK_SLOW = 1 << 0,
 42};
 43
 44static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
 45{
 46	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
 47}
 48
 49void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
 50{
 51	struct ablkcipher_buffer *p, *tmp;
 52
 53	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
 54		ablkcipher_buffer_write(p);
 55		list_del(&p->entry);
 56		kfree(p);
 57	}
 58}
 59EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
 60
 61static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
 62					  struct ablkcipher_buffer *p)
 63{
 64	p->dst = walk->out;
 65	list_add_tail(&p->entry, &walk->buffers);
 66}
 67
 68/* Get a spot of the specified length that does not straddle a page.
 69 * The caller needs to ensure that there is enough space for this operation.
 70 */
 71static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
 72{
 73	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
 
 74	return max(start, end_page);
 75}
 76
 77static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
 78						unsigned int bsize)
 79{
 80	unsigned int n = bsize;
 81
 82	for (;;) {
 83		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
 84
 85		if (len_this_page > n)
 86			len_this_page = n;
 87		scatterwalk_advance(&walk->out, n);
 88		if (n == len_this_page)
 89			break;
 90		n -= len_this_page;
 91		scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
 92	}
 93
 94	return bsize;
 95}
 96
 97static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
 98						unsigned int n)
 99{
100	scatterwalk_advance(&walk->in, n);
101	scatterwalk_advance(&walk->out, n);
102
103	return n;
104}
105
106static int ablkcipher_walk_next(struct ablkcipher_request *req,
107				struct ablkcipher_walk *walk);
108
109int ablkcipher_walk_done(struct ablkcipher_request *req,
110			 struct ablkcipher_walk *walk, int err)
111{
112	struct crypto_tfm *tfm = req->base.tfm;
113	unsigned int nbytes = 0;
114
115	if (likely(err >= 0)) {
116		unsigned int n = walk->nbytes - err;
117
118		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
119			n = ablkcipher_done_fast(walk, n);
120		else if (WARN_ON(err)) {
121			err = -EINVAL;
122			goto err;
123		} else
124			n = ablkcipher_done_slow(walk, n);
125
126		nbytes = walk->total - n;
127		err = 0;
128	}
129
130	scatterwalk_done(&walk->in, 0, nbytes);
131	scatterwalk_done(&walk->out, 1, nbytes);
132
133err:
134	walk->total = nbytes;
135	walk->nbytes = nbytes;
136
137	if (nbytes) {
138		crypto_yield(req->base.flags);
139		return ablkcipher_walk_next(req, walk);
140	}
141
142	if (walk->iv != req->info)
143		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
144	kfree(walk->iv_buffer);
145
146	return err;
147}
148EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
149
150static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
151				       struct ablkcipher_walk *walk,
152				       unsigned int bsize,
153				       unsigned int alignmask,
154				       void **src_p, void **dst_p)
155{
156	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
157	struct ablkcipher_buffer *p;
158	void *src, *dst, *base;
159	unsigned int n;
160
161	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
162	n += (aligned_bsize * 3 - (alignmask + 1) +
163	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
164
165	p = kmalloc(n, GFP_ATOMIC);
166	if (!p)
167		return ablkcipher_walk_done(req, walk, -ENOMEM);
168
169	base = p + 1;
170
171	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
172	src = dst = ablkcipher_get_spot(dst, bsize);
173
174	p->len = bsize;
175	p->data = dst;
176
177	scatterwalk_copychunks(src, &walk->in, bsize, 0);
178
179	ablkcipher_queue_write(walk, p);
180
181	walk->nbytes = bsize;
182	walk->flags |= ABLKCIPHER_WALK_SLOW;
183
184	*src_p = src;
185	*dst_p = dst;
186
187	return 0;
188}
189
190static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
191				     struct crypto_tfm *tfm,
192				     unsigned int alignmask)
193{
194	unsigned bs = walk->blocksize;
195	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
196	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
197	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
198			    (alignmask + 1);
199	u8 *iv;
200
201	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
202	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
203	if (!walk->iv_buffer)
204		return -ENOMEM;
205
206	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
207	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
208	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
209	iv = ablkcipher_get_spot(iv, ivsize);
210
211	walk->iv = memcpy(iv, walk->iv, ivsize);
212	return 0;
213}
214
215static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
216				       struct ablkcipher_walk *walk)
217{
218	walk->src.page = scatterwalk_page(&walk->in);
219	walk->src.offset = offset_in_page(walk->in.offset);
220	walk->dst.page = scatterwalk_page(&walk->out);
221	walk->dst.offset = offset_in_page(walk->out.offset);
222
223	return 0;
224}
225
226static int ablkcipher_walk_next(struct ablkcipher_request *req,
227				struct ablkcipher_walk *walk)
228{
229	struct crypto_tfm *tfm = req->base.tfm;
230	unsigned int alignmask, bsize, n;
231	void *src, *dst;
232	int err;
233
234	alignmask = crypto_tfm_alg_alignmask(tfm);
235	n = walk->total;
236	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
237		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
238		return ablkcipher_walk_done(req, walk, -EINVAL);
239	}
240
241	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
242	src = dst = NULL;
243
244	bsize = min(walk->blocksize, n);
245	n = scatterwalk_clamp(&walk->in, n);
246	n = scatterwalk_clamp(&walk->out, n);
247
248	if (n < bsize ||
249	    !scatterwalk_aligned(&walk->in, alignmask) ||
250	    !scatterwalk_aligned(&walk->out, alignmask)) {
251		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
252					   &src, &dst);
253		goto set_phys_lowmem;
254	}
255
256	walk->nbytes = n;
257
258	return ablkcipher_next_fast(req, walk);
259
260set_phys_lowmem:
261	if (err >= 0) {
262		walk->src.page = virt_to_page(src);
263		walk->dst.page = virt_to_page(dst);
264		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
265		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
266	}
267
268	return err;
269}
270
271static int ablkcipher_walk_first(struct ablkcipher_request *req,
272				 struct ablkcipher_walk *walk)
273{
274	struct crypto_tfm *tfm = req->base.tfm;
275	unsigned int alignmask;
276
277	alignmask = crypto_tfm_alg_alignmask(tfm);
278	if (WARN_ON_ONCE(in_irq()))
279		return -EDEADLK;
280
 
281	walk->nbytes = walk->total;
282	if (unlikely(!walk->total))
283		return 0;
284
285	walk->iv_buffer = NULL;
286	walk->iv = req->info;
287	if (unlikely(((unsigned long)walk->iv & alignmask))) {
288		int err = ablkcipher_copy_iv(walk, tfm, alignmask);
 
289		if (err)
290			return err;
291	}
292
293	scatterwalk_start(&walk->in, walk->in.sg);
294	scatterwalk_start(&walk->out, walk->out.sg);
295
296	return ablkcipher_walk_next(req, walk);
297}
298
299int ablkcipher_walk_phys(struct ablkcipher_request *req,
300			 struct ablkcipher_walk *walk)
301{
302	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
303	return ablkcipher_walk_first(req, walk);
304}
305EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
306
307static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
308			    unsigned int keylen)
309{
310	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
311	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
312	int ret;
313	u8 *buffer, *alignbuffer;
314	unsigned long absize;
315
316	absize = keylen + alignmask;
317	buffer = kmalloc(absize, GFP_ATOMIC);
318	if (!buffer)
319		return -ENOMEM;
320
321	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
322	memcpy(alignbuffer, key, keylen);
323	ret = cipher->setkey(tfm, alignbuffer, keylen);
324	memset(alignbuffer, 0, keylen);
325	kfree(buffer);
326	return ret;
327}
328
329static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
330		  unsigned int keylen)
331{
332	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
333	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
334
335	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
336		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
337		return -EINVAL;
338	}
339
340	if ((unsigned long)key & alignmask)
341		return setkey_unaligned(tfm, key, keylen);
342
343	return cipher->setkey(tfm, key, keylen);
344}
345
346static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
347					      u32 mask)
348{
349	return alg->cra_ctxsize;
350}
351
352int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
353{
354	return crypto_ablkcipher_encrypt(&req->creq);
355}
356
357int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
358{
359	return crypto_ablkcipher_decrypt(&req->creq);
360}
361
362static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
363				      u32 mask)
364{
365	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
366	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
367
368	if (alg->ivsize > PAGE_SIZE / 8)
369		return -EINVAL;
370
371	crt->setkey = setkey;
372	crt->encrypt = alg->encrypt;
373	crt->decrypt = alg->decrypt;
374	if (!alg->ivsize) {
375		crt->givencrypt = skcipher_null_givencrypt;
376		crt->givdecrypt = skcipher_null_givdecrypt;
377	}
378	crt->base = __crypto_ablkcipher_cast(tfm);
379	crt->ivsize = alg->ivsize;
380
381	return 0;
382}
383
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
384static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
385	__attribute__ ((unused));
386static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
387{
388	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
389
390	seq_printf(m, "type         : ablkcipher\n");
391	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
392					     "yes" : "no");
393	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
394	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
395	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
396	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
397	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
398}
399
400const struct crypto_type crypto_ablkcipher_type = {
401	.ctxsize = crypto_ablkcipher_ctxsize,
402	.init = crypto_init_ablkcipher_ops,
403#ifdef CONFIG_PROC_FS
404	.show = crypto_ablkcipher_show,
405#endif
 
406};
407EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
408
409static int no_givdecrypt(struct skcipher_givcrypt_request *req)
410{
411	return -ENOSYS;
412}
413
414static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
415				      u32 mask)
416{
417	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
418	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
419
420	if (alg->ivsize > PAGE_SIZE / 8)
421		return -EINVAL;
422
423	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
424		      alg->setkey : setkey;
425	crt->encrypt = alg->encrypt;
426	crt->decrypt = alg->decrypt;
427	crt->givencrypt = alg->givencrypt;
428	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
429	crt->base = __crypto_ablkcipher_cast(tfm);
430	crt->ivsize = alg->ivsize;
431
432	return 0;
433}
434
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
435static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
436	__attribute__ ((unused));
437static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
438{
439	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
440
441	seq_printf(m, "type         : givcipher\n");
442	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
443					     "yes" : "no");
444	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
445	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
446	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
447	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
448	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
449}
450
451const struct crypto_type crypto_givcipher_type = {
452	.ctxsize = crypto_ablkcipher_ctxsize,
453	.init = crypto_init_givcipher_ops,
454#ifdef CONFIG_PROC_FS
455	.show = crypto_givcipher_show,
456#endif
 
457};
458EXPORT_SYMBOL_GPL(crypto_givcipher_type);
459
460const char *crypto_default_geniv(const struct crypto_alg *alg)
461{
462	if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
463	     CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
464					 alg->cra_ablkcipher.ivsize) !=
465	    alg->cra_blocksize)
466		return "chainiv";
467
468	return alg->cra_flags & CRYPTO_ALG_ASYNC ?
469	       "eseqiv" : skcipher_default_geniv;
470}
471
472static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
473{
474	struct rtattr *tb[3];
475	struct {
476		struct rtattr attr;
477		struct crypto_attr_type data;
478	} ptype;
479	struct {
480		struct rtattr attr;
481		struct crypto_attr_alg data;
482	} palg;
483	struct crypto_template *tmpl;
484	struct crypto_instance *inst;
485	struct crypto_alg *larval;
486	const char *geniv;
487	int err;
488
489	larval = crypto_larval_lookup(alg->cra_driver_name,
490				      (type & ~CRYPTO_ALG_TYPE_MASK) |
491				      CRYPTO_ALG_TYPE_GIVCIPHER,
492				      mask | CRYPTO_ALG_TYPE_MASK);
493	err = PTR_ERR(larval);
494	if (IS_ERR(larval))
495		goto out;
496
497	err = -EAGAIN;
498	if (!crypto_is_larval(larval))
499		goto drop_larval;
500
501	ptype.attr.rta_len = sizeof(ptype);
502	ptype.attr.rta_type = CRYPTOA_TYPE;
503	ptype.data.type = type | CRYPTO_ALG_GENIV;
504	/* GENIV tells the template that we're making a default geniv. */
505	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
506	tb[0] = &ptype.attr;
507
508	palg.attr.rta_len = sizeof(palg);
509	palg.attr.rta_type = CRYPTOA_ALG;
510	/* Must use the exact name to locate ourselves. */
511	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
512	tb[1] = &palg.attr;
513
514	tb[2] = NULL;
515
516	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
517	    CRYPTO_ALG_TYPE_BLKCIPHER)
518		geniv = alg->cra_blkcipher.geniv;
519	else
520		geniv = alg->cra_ablkcipher.geniv;
521
522	if (!geniv)
523		geniv = crypto_default_geniv(alg);
524
525	tmpl = crypto_lookup_template(geniv);
526	err = -ENOENT;
527	if (!tmpl)
528		goto kill_larval;
529
 
 
 
 
 
 
 
530	inst = tmpl->alloc(tb);
531	err = PTR_ERR(inst);
532	if (IS_ERR(inst))
533		goto put_tmpl;
534
535	if ((err = crypto_register_instance(tmpl, inst))) {
 
536		tmpl->free(inst);
537		goto put_tmpl;
538	}
539
 
540	/* Redo the lookup to use the instance we just registered. */
541	err = -EAGAIN;
542
543put_tmpl:
544	crypto_tmpl_put(tmpl);
545kill_larval:
546	crypto_larval_kill(larval);
547drop_larval:
548	crypto_mod_put(larval);
549out:
550	crypto_mod_put(alg);
551	return err;
552}
553
554static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
555						 u32 mask)
556{
557	struct crypto_alg *alg;
558
559	alg = crypto_alg_mod_lookup(name, type, mask);
560	if (IS_ERR(alg))
561		return alg;
562
563	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
564	    CRYPTO_ALG_TYPE_GIVCIPHER)
565		return alg;
566
567	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
568	      CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
569					  alg->cra_ablkcipher.ivsize))
570		return alg;
571
572	crypto_mod_put(alg);
573	alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
574				    mask & ~CRYPTO_ALG_TESTED);
575	if (IS_ERR(alg))
576		return alg;
577
578	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
579	    CRYPTO_ALG_TYPE_GIVCIPHER) {
580		if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
581			crypto_mod_put(alg);
582			alg = ERR_PTR(-ENOENT);
583		}
584		return alg;
585	}
586
587	BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
588		 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
589					     alg->cra_ablkcipher.ivsize));
590
591	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
592}
 
593
594int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
595			 u32 type, u32 mask)
596{
597	struct crypto_alg *alg;
598	int err;
599
600	type = crypto_skcipher_type(type);
601	mask = crypto_skcipher_mask(mask);
602
603	alg = crypto_lookup_skcipher(name, type, mask);
604	if (IS_ERR(alg))
605		return PTR_ERR(alg);
606
607	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
608	crypto_mod_put(alg);
609	return err;
610}
611EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
612
613struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
614						  u32 type, u32 mask)
615{
616	struct crypto_tfm *tfm;
617	int err;
618
619	type = crypto_skcipher_type(type);
620	mask = crypto_skcipher_mask(mask);
621
622	for (;;) {
623		struct crypto_alg *alg;
624
625		alg = crypto_lookup_skcipher(alg_name, type, mask);
626		if (IS_ERR(alg)) {
627			err = PTR_ERR(alg);
628			goto err;
629		}
630
631		tfm = __crypto_alloc_tfm(alg, type, mask);
632		if (!IS_ERR(tfm))
633			return __crypto_ablkcipher_cast(tfm);
634
635		crypto_mod_put(alg);
636		err = PTR_ERR(tfm);
637
638err:
639		if (err != -EAGAIN)
640			break;
641		if (signal_pending(current)) {
642			err = -EINTR;
643			break;
644		}
645	}
646
647	return ERR_PTR(err);
648}
649EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
650
651static int __init skcipher_module_init(void)
652{
653	skcipher_default_geniv = num_possible_cpus() > 1 ?
654				 "eseqiv" : "chainiv";
655	return 0;
656}
657
658static void skcipher_module_exit(void)
659{
660}
661
662module_init(skcipher_module_init);
663module_exit(skcipher_module_exit);