2 * Block chaining cipher operations.
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.
8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
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)
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>
33 BLKCIPHER_WALK_PHYS = 1 << 0,
34 BLKCIPHER_WALK_SLOW = 1 << 1,
35 BLKCIPHER_WALK_COPY = 1 << 2,
36 BLKCIPHER_WALK_DIFF = 1 << 3,
39 static int blkcipher_walk_next(struct blkcipher_desc *desc,
40 struct blkcipher_walk *walk);
41 static int blkcipher_walk_first(struct blkcipher_desc *desc,
42 struct blkcipher_walk *walk);
44 static inline void blkcipher_map_src(struct blkcipher_walk *walk)
46 walk->src.virt.addr = scatterwalk_map(&walk->in);
49 static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
51 walk->dst.virt.addr = scatterwalk_map(&walk->out);
54 static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
56 scatterwalk_unmap(walk->src.virt.addr);
59 static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
61 scatterwalk_unmap(walk->dst.virt.addr);
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.
67 static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
69 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
70 return max(start, end_page);
73 static inline unsigned int blkcipher_done_slow(struct blkcipher_walk *walk,
78 addr = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
79 addr = blkcipher_get_spot(addr, bsize);
80 scatterwalk_copychunks(addr, &walk->out, bsize, 1);
84 static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
87 if (walk->flags & BLKCIPHER_WALK_COPY) {
88 blkcipher_map_dst(walk);
89 memcpy(walk->dst.virt.addr, walk->page, n);
90 blkcipher_unmap_dst(walk);
91 } else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
92 if (walk->flags & BLKCIPHER_WALK_DIFF)
93 blkcipher_unmap_dst(walk);
94 blkcipher_unmap_src(walk);
97 scatterwalk_advance(&walk->in, n);
98 scatterwalk_advance(&walk->out, n);
103 int blkcipher_walk_done(struct blkcipher_desc *desc,
104 struct blkcipher_walk *walk, int err)
106 unsigned int nbytes = 0;
108 if (likely(err >= 0)) {
109 unsigned int n = walk->nbytes - err;
111 if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
112 n = blkcipher_done_fast(walk, n);
113 else if (WARN_ON(err)) {
117 n = blkcipher_done_slow(walk, n);
119 nbytes = walk->total - n;
123 scatterwalk_done(&walk->in, 0, nbytes);
124 scatterwalk_done(&walk->out, 1, nbytes);
127 walk->total = nbytes;
128 walk->nbytes = nbytes;
131 crypto_yield(desc->flags);
132 return blkcipher_walk_next(desc, walk);
135 if (walk->iv != desc->info)
136 memcpy(desc->info, walk->iv, walk->ivsize);
137 if (walk->buffer != walk->page)
140 free_page((unsigned long)walk->page);
144 EXPORT_SYMBOL_GPL(blkcipher_walk_done);
146 static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
147 struct blkcipher_walk *walk,
149 unsigned int alignmask)
152 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
157 walk->buffer = walk->page;
161 n = aligned_bsize * 3 - (alignmask + 1) +
162 (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
163 walk->buffer = kmalloc(n, GFP_ATOMIC);
165 return blkcipher_walk_done(desc, walk, -ENOMEM);
168 walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
170 walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
171 walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
172 aligned_bsize, bsize);
174 scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
176 walk->nbytes = bsize;
177 walk->flags |= BLKCIPHER_WALK_SLOW;
182 static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
184 u8 *tmp = walk->page;
186 blkcipher_map_src(walk);
187 memcpy(tmp, walk->src.virt.addr, walk->nbytes);
188 blkcipher_unmap_src(walk);
190 walk->src.virt.addr = tmp;
191 walk->dst.virt.addr = tmp;
196 static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
197 struct blkcipher_walk *walk)
201 walk->src.phys.page = scatterwalk_page(&walk->in);
202 walk->src.phys.offset = offset_in_page(walk->in.offset);
203 walk->dst.phys.page = scatterwalk_page(&walk->out);
204 walk->dst.phys.offset = offset_in_page(walk->out.offset);
206 if (walk->flags & BLKCIPHER_WALK_PHYS)
209 diff = walk->src.phys.offset - walk->dst.phys.offset;
210 diff |= walk->src.virt.page - walk->dst.virt.page;
212 blkcipher_map_src(walk);
213 walk->dst.virt.addr = walk->src.virt.addr;
216 walk->flags |= BLKCIPHER_WALK_DIFF;
217 blkcipher_map_dst(walk);
223 static int blkcipher_walk_next(struct blkcipher_desc *desc,
224 struct blkcipher_walk *walk)
231 if (unlikely(n < walk->cipher_blocksize)) {
232 desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
233 return blkcipher_walk_done(desc, walk, -EINVAL);
236 walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
237 BLKCIPHER_WALK_DIFF);
238 if (!scatterwalk_aligned(&walk->in, walk->alignmask) ||
239 !scatterwalk_aligned(&walk->out, walk->alignmask)) {
240 walk->flags |= BLKCIPHER_WALK_COPY;
242 walk->page = (void *)__get_free_page(GFP_ATOMIC);
248 bsize = min(walk->walk_blocksize, n);
249 n = scatterwalk_clamp(&walk->in, n);
250 n = scatterwalk_clamp(&walk->out, n);
252 if (unlikely(n < bsize)) {
253 err = blkcipher_next_slow(desc, walk, bsize, walk->alignmask);
254 goto set_phys_lowmem;
258 if (walk->flags & BLKCIPHER_WALK_COPY) {
259 err = blkcipher_next_copy(walk);
260 goto set_phys_lowmem;
263 return blkcipher_next_fast(desc, walk);
266 if (walk->flags & BLKCIPHER_WALK_PHYS) {
267 walk->src.phys.page = virt_to_page(walk->src.virt.addr);
268 walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
269 walk->src.phys.offset &= PAGE_SIZE - 1;
270 walk->dst.phys.offset &= PAGE_SIZE - 1;
275 static inline int blkcipher_copy_iv(struct blkcipher_walk *walk)
277 unsigned bs = walk->walk_blocksize;
278 unsigned aligned_bs = ALIGN(bs, walk->alignmask + 1);
279 unsigned int size = aligned_bs * 2 +
280 walk->ivsize + max(aligned_bs, walk->ivsize) -
281 (walk->alignmask + 1);
284 size += walk->alignmask & ~(crypto_tfm_ctx_alignment() - 1);
285 walk->buffer = kmalloc(size, GFP_ATOMIC);
289 iv = (u8 *)ALIGN((unsigned long)walk->buffer, walk->alignmask + 1);
290 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
291 iv = blkcipher_get_spot(iv, bs) + aligned_bs;
292 iv = blkcipher_get_spot(iv, walk->ivsize);
294 walk->iv = memcpy(iv, walk->iv, walk->ivsize);
298 int blkcipher_walk_virt(struct blkcipher_desc *desc,
299 struct blkcipher_walk *walk)
301 walk->flags &= ~BLKCIPHER_WALK_PHYS;
302 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
303 walk->cipher_blocksize = walk->walk_blocksize;
304 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
305 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
306 return blkcipher_walk_first(desc, walk);
308 EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
310 int blkcipher_walk_phys(struct blkcipher_desc *desc,
311 struct blkcipher_walk *walk)
313 walk->flags |= BLKCIPHER_WALK_PHYS;
314 walk->walk_blocksize = crypto_blkcipher_blocksize(desc->tfm);
315 walk->cipher_blocksize = walk->walk_blocksize;
316 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
317 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
318 return blkcipher_walk_first(desc, walk);
320 EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
322 static int blkcipher_walk_first(struct blkcipher_desc *desc,
323 struct blkcipher_walk *walk)
325 if (WARN_ON_ONCE(in_irq()))
328 walk->nbytes = walk->total;
329 if (unlikely(!walk->total))
333 walk->iv = desc->info;
334 if (unlikely(((unsigned long)walk->iv & walk->alignmask))) {
335 int err = blkcipher_copy_iv(walk);
340 scatterwalk_start(&walk->in, walk->in.sg);
341 scatterwalk_start(&walk->out, walk->out.sg);
344 return blkcipher_walk_next(desc, walk);
347 int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
348 struct blkcipher_walk *walk,
349 unsigned int blocksize)
351 walk->flags &= ~BLKCIPHER_WALK_PHYS;
352 walk->walk_blocksize = blocksize;
353 walk->cipher_blocksize = crypto_blkcipher_blocksize(desc->tfm);
354 walk->ivsize = crypto_blkcipher_ivsize(desc->tfm);
355 walk->alignmask = crypto_blkcipher_alignmask(desc->tfm);
356 return blkcipher_walk_first(desc, walk);
358 EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);
360 static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
363 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
364 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
366 u8 *buffer, *alignbuffer;
367 unsigned long absize;
369 absize = keylen + alignmask;
370 buffer = kmalloc(absize, GFP_ATOMIC);
374 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
375 memcpy(alignbuffer, key, keylen);
376 ret = cipher->setkey(tfm, alignbuffer, keylen);
377 memset(alignbuffer, 0, keylen);
382 static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
384 struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
385 unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
387 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
388 tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
392 if ((unsigned long)key & alignmask)
393 return setkey_unaligned(tfm, key, keylen);
395 return cipher->setkey(tfm, key, keylen);
398 static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
401 return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
404 static int async_encrypt(struct ablkcipher_request *req)
406 struct crypto_tfm *tfm = req->base.tfm;
407 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
408 struct blkcipher_desc desc = {
409 .tfm = __crypto_blkcipher_cast(tfm),
411 .flags = req->base.flags,
415 return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
418 static int async_decrypt(struct ablkcipher_request *req)
420 struct crypto_tfm *tfm = req->base.tfm;
421 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
422 struct blkcipher_desc desc = {
423 .tfm = __crypto_blkcipher_cast(tfm),
425 .flags = req->base.flags,
428 return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
431 static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
434 struct blkcipher_alg *cipher = &alg->cra_blkcipher;
435 unsigned int len = alg->cra_ctxsize;
437 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
439 len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
440 len += cipher->ivsize;
446 static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
448 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
449 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
451 crt->setkey = async_setkey;
452 crt->encrypt = async_encrypt;
453 crt->decrypt = async_decrypt;
455 crt->givencrypt = skcipher_null_givencrypt;
456 crt->givdecrypt = skcipher_null_givdecrypt;
458 crt->base = __crypto_ablkcipher_cast(tfm);
459 crt->ivsize = alg->ivsize;
464 static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
466 struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
467 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
468 unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
471 crt->setkey = setkey;
472 crt->encrypt = alg->encrypt;
473 crt->decrypt = alg->decrypt;
475 addr = (unsigned long)crypto_tfm_ctx(tfm);
476 addr = ALIGN(addr, align);
477 addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
478 crt->iv = (void *)addr;
483 static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
485 struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
487 if (alg->ivsize > PAGE_SIZE / 8)
490 if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
491 return crypto_init_blkcipher_ops_sync(tfm);
493 return crypto_init_blkcipher_ops_async(tfm);
497 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
499 struct crypto_report_blkcipher rblkcipher;
501 strncpy(rblkcipher.type, "blkcipher", sizeof(rblkcipher.type));
502 strncpy(rblkcipher.geniv, alg->cra_blkcipher.geniv ?: "<default>",
503 sizeof(rblkcipher.geniv));
505 rblkcipher.blocksize = alg->cra_blocksize;
506 rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
507 rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
508 rblkcipher.ivsize = alg->cra_blkcipher.ivsize;
510 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
511 sizeof(struct crypto_report_blkcipher), &rblkcipher))
512 goto nla_put_failure;
519 static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
525 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
526 __attribute__ ((unused));
527 static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
529 seq_printf(m, "type : blkcipher\n");
530 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
531 seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
532 seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
533 seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
534 seq_printf(m, "geniv : %s\n", alg->cra_blkcipher.geniv ?:
538 const struct crypto_type crypto_blkcipher_type = {
539 .ctxsize = crypto_blkcipher_ctxsize,
540 .init = crypto_init_blkcipher_ops,
541 #ifdef CONFIG_PROC_FS
542 .show = crypto_blkcipher_show,
544 .report = crypto_blkcipher_report,
546 EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
548 static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
549 const char *name, u32 type, u32 mask)
551 struct crypto_alg *alg;
554 type = crypto_skcipher_type(type);
555 mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;
557 alg = crypto_alg_mod_lookup(name, type, mask);
561 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
566 struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
567 struct rtattr **tb, u32 type,
571 int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
572 unsigned int keylen);
573 int (*encrypt)(struct ablkcipher_request *req);
574 int (*decrypt)(struct ablkcipher_request *req);
576 unsigned int min_keysize;
577 unsigned int max_keysize;
583 struct crypto_skcipher_spawn *spawn;
584 struct crypto_attr_type *algt;
585 struct crypto_instance *inst;
586 struct crypto_alg *alg;
589 algt = crypto_get_attr_type(tb);
591 return ERR_CAST(algt);
593 if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
595 return ERR_PTR(-EINVAL);
597 name = crypto_attr_alg_name(tb[1]);
599 return ERR_CAST(name);
601 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
603 return ERR_PTR(-ENOMEM);
605 spawn = crypto_instance_ctx(inst);
607 /* Ignore async algorithms if necessary. */
608 mask |= crypto_requires_sync(algt->type, algt->mask);
610 crypto_set_skcipher_spawn(spawn, inst);
611 err = crypto_grab_nivcipher(spawn, name, type, mask);
615 alg = crypto_skcipher_spawn_alg(spawn);
617 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
618 CRYPTO_ALG_TYPE_BLKCIPHER) {
619 balg.ivsize = alg->cra_blkcipher.ivsize;
620 balg.min_keysize = alg->cra_blkcipher.min_keysize;
621 balg.max_keysize = alg->cra_blkcipher.max_keysize;
623 balg.setkey = async_setkey;
624 balg.encrypt = async_encrypt;
625 balg.decrypt = async_decrypt;
627 balg.geniv = alg->cra_blkcipher.geniv;
629 balg.ivsize = alg->cra_ablkcipher.ivsize;
630 balg.min_keysize = alg->cra_ablkcipher.min_keysize;
631 balg.max_keysize = alg->cra_ablkcipher.max_keysize;
633 balg.setkey = alg->cra_ablkcipher.setkey;
634 balg.encrypt = alg->cra_ablkcipher.encrypt;
635 balg.decrypt = alg->cra_ablkcipher.decrypt;
637 balg.geniv = alg->cra_ablkcipher.geniv;
645 * This is only true if we're constructing an algorithm with its
646 * default IV generator. For the default generator we elide the
647 * template name and double-check the IV generator.
649 if (algt->mask & CRYPTO_ALG_GENIV) {
651 balg.geniv = crypto_default_geniv(alg);
653 if (strcmp(tmpl->name, balg.geniv))
656 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
657 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
658 CRYPTO_MAX_ALG_NAME);
661 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
662 "%s(%s)", tmpl->name, alg->cra_name) >=
665 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
666 "%s(%s)", tmpl->name, alg->cra_driver_name) >=
671 inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
672 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
673 inst->alg.cra_priority = alg->cra_priority;
674 inst->alg.cra_blocksize = alg->cra_blocksize;
675 inst->alg.cra_alignmask = alg->cra_alignmask;
676 inst->alg.cra_type = &crypto_givcipher_type;
678 inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
679 inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
680 inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
681 inst->alg.cra_ablkcipher.geniv = balg.geniv;
683 inst->alg.cra_ablkcipher.setkey = balg.setkey;
684 inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
685 inst->alg.cra_ablkcipher.decrypt = balg.decrypt;
691 crypto_drop_skcipher(spawn);
697 EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);
699 void skcipher_geniv_free(struct crypto_instance *inst)
701 crypto_drop_skcipher(crypto_instance_ctx(inst));
704 EXPORT_SYMBOL_GPL(skcipher_geniv_free);
706 int skcipher_geniv_init(struct crypto_tfm *tfm)
708 struct crypto_instance *inst = (void *)tfm->__crt_alg;
709 struct crypto_ablkcipher *cipher;
711 cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
713 return PTR_ERR(cipher);
715 tfm->crt_ablkcipher.base = cipher;
716 tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);
720 EXPORT_SYMBOL_GPL(skcipher_geniv_init);
722 void skcipher_geniv_exit(struct crypto_tfm *tfm)
724 crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
726 EXPORT_SYMBOL_GPL(skcipher_geniv_exit);
728 MODULE_LICENSE("GPL");
729 MODULE_DESCRIPTION("Generic block chaining cipher type");