Root/crypto/ablkcipher.c

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    strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
392    strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
393        sizeof(rblkcipher.geniv));
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    strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
473    strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
474        sizeof(rblkcipher.geniv));
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);
726

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