Root/crypto/blkcipher.c

1/*
2 * Block chaining cipher operations.
3 *
4 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
5 * multiple page boundaries by using temporary blocks. In user context,
6 * the kernel is given a chance to schedule us once per page.
7 *
8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the Free
12 * Software Foundation; either version 2 of the License, or (at your option)
13 * any later version.
14 *
15 */
16
17#include <crypto/internal/skcipher.h>
18#include <crypto/scatterwalk.h>
19#include <linux/errno.h>
20#include <linux/hardirq.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/scatterlist.h>
24#include <linux/seq_file.h>
25#include <linux/slab.h>
26#include <linux/string.h>
27#include <linux/cryptouser.h>
28#include <net/netlink.h>
29
30#include "internal.h"
31
32enum {
33    BLKCIPHER_WALK_PHYS = 1 << 0,
34    BLKCIPHER_WALK_SLOW = 1 << 1,
35    BLKCIPHER_WALK_COPY = 1 << 2,
36    BLKCIPHER_WALK_DIFF = 1 << 3,
37};
38
39static int blkcipher_walk_next(struct blkcipher_desc *desc,
40                   struct blkcipher_walk *walk);
41static int blkcipher_walk_first(struct blkcipher_desc *desc,
42                struct blkcipher_walk *walk);
43
44static inline void blkcipher_map_src(struct blkcipher_walk *walk)
45{
46    walk->src.virt.addr = scatterwalk_map(&walk->in);
47}
48
49static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
50{
51    walk->dst.virt.addr = scatterwalk_map(&walk->out);
52}
53
54static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
55{
56    scatterwalk_unmap(walk->src.virt.addr);
57}
58
59static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
60{
61    scatterwalk_unmap(walk->dst.virt.addr);
62}
63
64/* Get a spot of the specified length that does not straddle a page.
65 * The caller needs to ensure that there is enough space for this operation.
66 */
67static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
68{
69    u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
70    return max(start, end_page);
71}
72
73static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
74                           struct blkcipher_walk *walk,
75                           unsigned int bsize)
76{
77    u8 *addr;
78    unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
79
80    addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
81    addr = blkcipher_get_spot(addr, bsize);
82    scatterwalk_copychunks(addr, &walk->out, bsize, 1);
83    return bsize;
84}
85
86static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
87                           unsigned int n)
88{
89    if (walk->flags & BLKCIPHER_WALK_COPY) {
90        blkcipher_map_dst(walk);
91        memcpy(walk->dst.virt.addr, walk->page, n);
92        blkcipher_unmap_dst(walk);
93    } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
94        if (walk->flags & BLKCIPHER_WALK_DIFF)
95            blkcipher_unmap_dst(walk);
96        blkcipher_unmap_src(walk);
97    }
98
99    scatterwalk_advance(&walk->in, n);
100    scatterwalk_advance(&walk->out, n);
101
102    return n;
103}
104
105int blkcipher_walk_done(struct blkcipher_desc *desc,
106            struct blkcipher_walk *walk, int err)
107{
108    struct crypto_blkcipher *tfm = desc->tfm;
109    unsigned int nbytes = 0;
110
111    if (likely(err >= 0)) {
112        unsigned int n = walk->nbytes - err;
113
114        if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
115            n = blkcipher_done_fast(walk, n);
116        else if (WARN_ON(err)) {
117            err = -EINVAL;
118            goto err;
119        } else
120            n = blkcipher_done_slow(tfm, walk, n);
121
122        nbytes = walk->total - n;
123        err = 0;
124    }
125
126    scatterwalk_done(&walk->in, 0, nbytes);
127    scatterwalk_done(&walk->out, 1, nbytes);
128
129err:
130    walk->total = nbytes;
131    walk->nbytes = nbytes;
132
133    if (nbytes) {
134        crypto_yield(desc->flags);
135        return blkcipher_walk_next(desc, walk);
136    }
137
138    if (walk->iv != desc->info)
139        memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
140    if (walk->buffer != walk->page)
141        kfree(walk->buffer);
142    if (walk->page)
143        free_page((unsigned long)walk->page);
144
145    return err;
146}
147EXPORT_SYMBOL_GPL(blkcipher_walk_done);
148
149static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
150                      struct blkcipher_walk *walk,
151                      unsigned int bsize,
152                      unsigned int alignmask)
153{
154    unsigned int n;
155    unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
156
157    if (walk->buffer)
158        goto ok;
159
160    walk->buffer = walk->page;
161    if (walk->buffer)
162        goto ok;
163
164    n = aligned_bsize * 3 - (alignmask + 1) +
165        (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
166    walk->buffer = kmalloc(n, GFP_ATOMIC);
167    if (!walk->buffer)
168        return blkcipher_walk_done(desc, walk, -ENOMEM);
169
170ok:
171    walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
172                      alignmask + 1);
173    walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
174    walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
175                         aligned_bsize, bsize);
176
177    scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
178
179    walk->nbytes = bsize;
180    walk->flags |= BLKCIPHER_WALK_SLOW;
181
182    return 0;
183}
184
185static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
186{
187    u8 *tmp = walk->page;
188
189    blkcipher_map_src(walk);
190    memcpy(tmp, walk->src.virt.addr, walk->nbytes);
191    blkcipher_unmap_src(walk);
192
193    walk->src.virt.addr = tmp;
194    walk->dst.virt.addr = tmp;
195
196    return 0;
197}
198
199static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
200                      struct blkcipher_walk *walk)
201{
202    unsigned long diff;
203
204    walk->src.phys.page = scatterwalk_page(&walk->in);
205    walk->src.phys.offset = offset_in_page(walk->in.offset);
206    walk->dst.phys.page = scatterwalk_page(&walk->out);
207    walk->dst.phys.offset = offset_in_page(walk->out.offset);
208
209    if (walk->flags & BLKCIPHER_WALK_PHYS)
210        return 0;
211
212    diff = walk->src.phys.offset - walk->dst.phys.offset;
213    diff |= walk->src.virt.page - walk->dst.virt.page;
214
215    blkcipher_map_src(walk);
216    walk->dst.virt.addr = walk->src.virt.addr;
217
218    if (diff) {
219        walk->flags |= BLKCIPHER_WALK_DIFF;
220        blkcipher_map_dst(walk);
221    }
222
223    return 0;
224}
225
226static int blkcipher_walk_next(struct blkcipher_desc *desc,
227                   struct blkcipher_walk *walk)
228{
229    struct crypto_blkcipher *tfm = desc->tfm;
230    unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
231    unsigned int bsize;
232    unsigned int n;
233    int err;
234
235    n = walk->total;
236    if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
237        desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
238        return blkcipher_walk_done(desc, walk, -EINVAL);
239    }
240
241    walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
242             BLKCIPHER_WALK_DIFF);
243    if (!scatterwalk_aligned(&walk->in, alignmask) ||
244        !scatterwalk_aligned(&walk->out, alignmask)) {
245        walk->flags |= BLKCIPHER_WALK_COPY;
246        if (!walk->page) {
247            walk->page = (void *)__get_free_page(GFP_ATOMIC);
248            if (!walk->page)
249                n = 0;
250        }
251    }
252
253    bsize = min(walk->blocksize, n);
254    n = scatterwalk_clamp(&walk->in, n);
255    n = scatterwalk_clamp(&walk->out, n);
256
257    if (unlikely(n < bsize)) {
258        err = blkcipher_next_slow(desc, walk, bsize, alignmask);
259        goto set_phys_lowmem;
260    }
261
262    walk->nbytes = n;
263    if (walk->flags & BLKCIPHER_WALK_COPY) {
264        err = blkcipher_next_copy(walk);
265        goto set_phys_lowmem;
266    }
267
268    return blkcipher_next_fast(desc, walk);
269
270set_phys_lowmem:
271    if (walk->flags & BLKCIPHER_WALK_PHYS) {
272        walk->src.phys.page = virt_to_page(walk->src.virt.addr);
273        walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
274        walk->src.phys.offset &= PAGE_SIZE - 1;
275        walk->dst.phys.offset &= PAGE_SIZE - 1;
276    }
277    return err;
278}
279
280static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
281                    struct crypto_blkcipher *tfm,
282                    unsigned int alignmask)
283{
284    unsigned bs = walk->blocksize;
285    unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
286    unsigned aligned_bs = ALIGN(bs, alignmask + 1);
287    unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
288                (alignmask + 1);
289    u8 *iv;
290
291    size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
292    walk->buffer = kmalloc(size, GFP_ATOMIC);
293    if (!walk->buffer)
294        return -ENOMEM;
295
296    iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
297    iv = blkcipher_get_spot(iv, bs) + aligned_bs;
298    iv = blkcipher_get_spot(iv, bs) + aligned_bs;
299    iv = blkcipher_get_spot(iv, ivsize);
300
301    walk->iv = memcpy(iv, walk->iv, ivsize);
302    return 0;
303}
304
305int blkcipher_walk_virt(struct blkcipher_desc *desc,
306            struct blkcipher_walk *walk)
307{
308    walk->flags &= ~BLKCIPHER_WALK_PHYS;
309    walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
310    return blkcipher_walk_first(desc, walk);
311}
312EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
313
314int blkcipher_walk_phys(struct blkcipher_desc *desc,
315            struct blkcipher_walk *walk)
316{
317    walk->flags |= BLKCIPHER_WALK_PHYS;
318    walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
319    return blkcipher_walk_first(desc, walk);
320}
321EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
322
323static int blkcipher_walk_first(struct blkcipher_desc *desc,
324                struct blkcipher_walk *walk)
325{
326    struct crypto_blkcipher *tfm = desc->tfm;
327    unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
328
329    if (WARN_ON_ONCE(in_irq()))
330        return -EDEADLK;
331
332    walk->nbytes = walk->total;
333    if (unlikely(!walk->total))
334        return 0;
335
336    walk->buffer = NULL;
337    walk->iv = desc->info;
338    if (unlikely(((unsigned long)walk->iv & alignmask))) {
339        int err = blkcipher_copy_iv(walk, tfm, alignmask);
340        if (err)
341            return err;
342    }
343
344    scatterwalk_start(&walk->in, walk->in.sg);
345    scatterwalk_start(&walk->out, walk->out.sg);
346    walk->page = NULL;
347
348    return blkcipher_walk_next(desc, walk);
349}
350
351int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
352                  struct blkcipher_walk *walk,
353                  unsigned int blocksize)
354{
355    walk->flags &= ~BLKCIPHER_WALK_PHYS;
356    walk->blocksize = blocksize;
357    return blkcipher_walk_first(desc, walk);
358}
359EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
360
361static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
362                unsigned int keylen)
363{
364    struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
365    unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
366    int ret;
367    u8 *buffer, *alignbuffer;
368    unsigned long absize;
369
370    absize = keylen + alignmask;
371    buffer = kmalloc(absize, GFP_ATOMIC);
372    if (!buffer)
373        return -ENOMEM;
374
375    alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
376    memcpy(alignbuffer, key, keylen);
377    ret = cipher->setkey(tfm, alignbuffer, keylen);
378    memset(alignbuffer, 0, keylen);
379    kfree(buffer);
380    return ret;
381}
382
383static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
384{
385    struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
386    unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
387
388    if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
389        tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
390        return -EINVAL;
391    }
392
393    if ((unsigned long)key & alignmask)
394        return setkey_unaligned(tfm, key, keylen);
395
396    return cipher->setkey(tfm, key, keylen);
397}
398
399static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
400            unsigned int keylen)
401{
402    return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
403}
404
405static int async_encrypt(struct ablkcipher_request *req)
406{
407    struct crypto_tfm *tfm = req->base.tfm;
408    struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
409    struct blkcipher_desc desc = {
410        .tfm = __crypto_blkcipher_cast(tfm),
411        .info = req->info,
412        .flags = req->base.flags,
413    };
414
415
416    return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
417}
418
419static int async_decrypt(struct ablkcipher_request *req)
420{
421    struct crypto_tfm *tfm = req->base.tfm;
422    struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
423    struct blkcipher_desc desc = {
424        .tfm = __crypto_blkcipher_cast(tfm),
425        .info = req->info,
426        .flags = req->base.flags,
427    };
428
429    return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
430}
431
432static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
433                         u32 mask)
434{
435    struct blkcipher_alg *cipher = &alg->cra_blkcipher;
436    unsigned int len = alg->cra_ctxsize;
437
438    if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
439        cipher->ivsize) {
440        len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
441        len += cipher->ivsize;
442    }
443
444    return len;
445}
446
447static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
448{
449    struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
450    struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
451
452    crt->setkey = async_setkey;
453    crt->encrypt = async_encrypt;
454    crt->decrypt = async_decrypt;
455    if (!alg->ivsize) {
456        crt->givencrypt = skcipher_null_givencrypt;
457        crt->givdecrypt = skcipher_null_givdecrypt;
458    }
459    crt->base = __crypto_ablkcipher_cast(tfm);
460    crt->ivsize = alg->ivsize;
461
462    return 0;
463}
464
465static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
466{
467    struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
468    struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
469    unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
470    unsigned long addr;
471
472    crt->setkey = setkey;
473    crt->encrypt = alg->encrypt;
474    crt->decrypt = alg->decrypt;
475
476    addr = (unsigned long)crypto_tfm_ctx(tfm);
477    addr = ALIGN(addr, align);
478    addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
479    crt->iv = (void *)addr;
480
481    return 0;
482}
483
484static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
485{
486    struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
487
488    if (alg->ivsize > PAGE_SIZE / 8)
489        return -EINVAL;
490
491    if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
492        return crypto_init_blkcipher_ops_sync(tfm);
493    else
494        return crypto_init_blkcipher_ops_async(tfm);
495}
496
497#ifdef CONFIG_NET
498static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
499{
500    struct crypto_report_blkcipher rblkcipher;
501
502    strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
503    strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
504        sizeof(rblkcipher.geniv));
505
506    rblkcipher.blocksize = alg->cra_blocksize;
507    rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
508    rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
509    rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
510
511    if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
512            sizeof(struct crypto_report_blkcipher), &rblkcipher))
513        goto nla_put_failure;
514    return 0;
515
516nla_put_failure:
517    return -EMSGSIZE;
518}
519#else
520static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
521{
522    return -ENOSYS;
523}
524#endif
525
526static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
527    __attribute__ ((unused));
528static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
529{
530    seq_printf(m, "type : blkcipher\n");
531    seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
532    seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
533    seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
534    seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
535    seq_printf(m, "geniv : %s\n", alg->cra_blkcipher.geniv ?:
536                         "<default>");
537}
538
539const struct crypto_type crypto_blkcipher_type = {
540    .ctxsize = crypto_blkcipher_ctxsize,
541    .init = crypto_init_blkcipher_ops,
542#ifdef CONFIG_PROC_FS
543    .show = crypto_blkcipher_show,
544#endif
545    .report = crypto_blkcipher_report,
546};
547EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
548
549static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
550                const char *name, u32 type, u32 mask)
551{
552    struct crypto_alg *alg;
553    int err;
554
555    type = crypto_skcipher_type(type);
556    mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
557
558    alg = crypto_alg_mod_lookup(name, type, mask);
559    if (IS_ERR(alg))
560        return PTR_ERR(alg);
561
562    err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
563    crypto_mod_put(alg);
564    return err;
565}
566
567struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
568                         struct rtattr **tb, u32 type,
569                         u32 mask)
570{
571    struct {
572        int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
573                  unsigned int keylen);
574        int (*encrypt)(struct ablkcipher_request *req);
575        int (*decrypt)(struct ablkcipher_request *req);
576
577        unsigned int min_keysize;
578        unsigned int max_keysize;
579        unsigned int ivsize;
580
581        const char *geniv;
582    } balg;
583    const char *name;
584    struct crypto_skcipher_spawn *spawn;
585    struct crypto_attr_type *algt;
586    struct crypto_instance *inst;
587    struct crypto_alg *alg;
588    int err;
589
590    algt = crypto_get_attr_type(tb);
591    if (IS_ERR(algt))
592        return ERR_CAST(algt);
593
594    if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
595        algt->mask)
596        return ERR_PTR(-EINVAL);
597
598    name = crypto_attr_alg_name(tb[1]);
599    if (IS_ERR(name))
600        return ERR_CAST(name);
601
602    inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
603    if (!inst)
604        return ERR_PTR(-ENOMEM);
605
606    spawn = crypto_instance_ctx(inst);
607
608    /* Ignore async algorithms if necessary. */
609    mask |= crypto_requires_sync(algt->type, algt->mask);
610
611    crypto_set_skcipher_spawn(spawn, inst);
612    err = crypto_grab_nivcipher(spawn, name, type, mask);
613    if (err)
614        goto err_free_inst;
615
616    alg = crypto_skcipher_spawn_alg(spawn);
617
618    if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
619        CRYPTO_ALG_TYPE_BLKCIPHER) {
620        balg.ivsize = alg->cra_blkcipher.ivsize;
621        balg.min_keysize = alg->cra_blkcipher.min_keysize;
622        balg.max_keysize = alg->cra_blkcipher.max_keysize;
623
624        balg.setkey = async_setkey;
625        balg.encrypt = async_encrypt;
626        balg.decrypt = async_decrypt;
627
628        balg.geniv = alg->cra_blkcipher.geniv;
629    } else {
630        balg.ivsize = alg->cra_ablkcipher.ivsize;
631        balg.min_keysize = alg->cra_ablkcipher.min_keysize;
632        balg.max_keysize = alg->cra_ablkcipher.max_keysize;
633
634        balg.setkey = alg->cra_ablkcipher.setkey;
635        balg.encrypt = alg->cra_ablkcipher.encrypt;
636        balg.decrypt = alg->cra_ablkcipher.decrypt;
637
638        balg.geniv = alg->cra_ablkcipher.geniv;
639    }
640
641    err = -EINVAL;
642    if (!balg.ivsize)
643        goto err_drop_alg;
644
645    /*
646     * This is only true if we're constructing an algorithm with its
647     * default IV generator. For the default generator we elide the
648     * template name and double-check the IV generator.
649     */
650    if (algt->mask & CRYPTO_ALG_GENIV) {
651        if (!balg.geniv)
652            balg.geniv = crypto_default_geniv(alg);
653        err = -EAGAIN;
654        if (strcmp(tmpl->name, balg.geniv))
655            goto err_drop_alg;
656
657        memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
658        memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
659               CRYPTO_MAX_ALG_NAME);
660    } else {
661        err = -ENAMETOOLONG;
662        if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
663                 "%s(%s)", tmpl->name, alg->cra_name) >=
664            CRYPTO_MAX_ALG_NAME)
665            goto err_drop_alg;
666        if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
667                 "%s(%s)", tmpl->name, alg->cra_driver_name) >=
668            CRYPTO_MAX_ALG_NAME)
669            goto err_drop_alg;
670    }
671
672    inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
673    inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
674    inst->alg.cra_priority = alg->cra_priority;
675    inst->alg.cra_blocksize = alg->cra_blocksize;
676    inst->alg.cra_alignmask = alg->cra_alignmask;
677    inst->alg.cra_type = &crypto_givcipher_type;
678
679    inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
680    inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
681    inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
682    inst->alg.cra_ablkcipher.geniv = balg.geniv;
683
684    inst->alg.cra_ablkcipher.setkey = balg.setkey;
685    inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
686    inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
687
688out:
689    return inst;
690
691err_drop_alg:
692    crypto_drop_skcipher(spawn);
693err_free_inst:
694    kfree(inst);
695    inst = ERR_PTR(err);
696    goto out;
697}
698EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
699
700void skcipher_geniv_free(struct crypto_instance *inst)
701{
702    crypto_drop_skcipher(crypto_instance_ctx(inst));
703    kfree(inst);
704}
705EXPORT_SYMBOL_GPL(skcipher_geniv_free);
706
707int skcipher_geniv_init(struct crypto_tfm *tfm)
708{
709    struct crypto_instance *inst = (void *)tfm->__crt_alg;
710    struct crypto_ablkcipher *cipher;
711
712    cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
713    if (IS_ERR(cipher))
714        return PTR_ERR(cipher);
715
716    tfm->crt_ablkcipher.base = cipher;
717    tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
718
719    return 0;
720}
721EXPORT_SYMBOL_GPL(skcipher_geniv_init);
722
723void skcipher_geniv_exit(struct crypto_tfm *tfm)
724{
725    crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
726}
727EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
728
729MODULE_LICENSE("GPL");
730MODULE_DESCRIPTION("Generic block chaining cipher type");
731

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