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

Archive Download this file



interactive