[linux.git] / crypto / ablkcipher.c

/*
 * Asynchronous block chaining cipher operations.
 *
 * This is the asynchronous version of blkcipher.c indicating completion
 * via a callback.
 *
 * Copyright (c) 2006 Herbert Xu <[email protected]>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <crypto/internal/skcipher.h>
#include <linux/cpumask.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/seq_file.h>

#include <crypto/scatterwalk.h>

#include "internal.h"

static const char *skcipher_default_geniv __read_mostly;

struct ablkcipher_buffer {
	struct list_head	entry;
	struct scatter_walk	dst;
	unsigned int		len;
	void			*data;
};

enum {
	ABLKCIPHER_WALK_SLOW = 1 << 0,
};

static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
{
	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
}

void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
{
	struct ablkcipher_buffer *p, *tmp;

	list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
		ablkcipher_buffer_write(p);
		list_del(&p->entry);
		kfree(p);
	}
}
EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);

static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
					  struct ablkcipher_buffer *p)
{
	p->dst = walk->out;
	list_add_tail(&p->entry, &walk->buffers);
}

/* Get a spot of the specified length that does not straddle a page.
 * The caller needs to ensure that there is enough space for this operation.
 */
static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
	return max(start, end_page);
}

static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
						unsigned int bsize)
{
	unsigned int n = bsize;

	for (;;) {
		unsigned int len_this_page = scatterwalk_pagelen(&walk->out);

		if (len_this_page > n)
			len_this_page = n;
		scatterwalk_advance(&walk->out, n);
		if (n == len_this_page)
			break;
		n -= len_this_page;
		scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
	}

	return bsize;
}

static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
						unsigned int n)
{
	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);

	return n;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
				struct ablkcipher_walk *walk);

int ablkcipher_walk_done(struct ablkcipher_request *req,
			 struct ablkcipher_walk *walk, int err)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int nbytes = 0;

	if (likely(err >= 0)) {
		unsigned int n = walk->nbytes - err;

		if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
			n = ablkcipher_done_fast(walk, n);
		else if (WARN_ON(err)) {
			err = -EINVAL;
			goto err;
		} else
			n = ablkcipher_done_slow(walk, n);

		nbytes = walk->total - n;
		err = 0;
	}

	scatterwalk_done(&walk->in, 0, nbytes);
	scatterwalk_done(&walk->out, 1, nbytes);

err:
	walk->total = nbytes;
	walk->nbytes = nbytes;

	if (nbytes) {
		crypto_yield(req->base.flags);
		return ablkcipher_walk_next(req, walk);
	}

	if (walk->iv != req->info)
		memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
	if (walk->iv_buffer)
		kfree(walk->iv_buffer);

	return err;
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_done);

static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
				       struct ablkcipher_walk *walk,
				       unsigned int bsize,
				       unsigned int alignmask,
				       void **src_p, void **dst_p)
{
	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
	struct ablkcipher_buffer *p;
	void *src, *dst, *base;
	unsigned int n;

	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
	n += (aligned_bsize * 3 - (alignmask + 1) +
	      (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));

	p = kmalloc(n, GFP_ATOMIC);
	if (!p)
		return ablkcipher_walk_done(req, walk, -ENOMEM);

	base = p + 1;

	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
	src = dst = ablkcipher_get_spot(dst, bsize);

	p->len = bsize;
	p->data = dst;

	scatterwalk_copychunks(src, &walk->in, bsize, 0);

	ablkcipher_queue_write(walk, p);

	walk->nbytes = bsize;
	walk->flags |= ABLKCIPHER_WALK_SLOW;

	*src_p = src;
	*dst_p = dst;

	return 0;
}

static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
				     struct crypto_tfm *tfm,
				     unsigned int alignmask)
{
	unsigned bs = walk->blocksize;
	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
			    (alignmask + 1);
	u8 *iv;

	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
	if (!walk->iv_buffer)
		return -ENOMEM;

	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	iv = ablkcipher_get_spot(iv, ivsize);

	walk->iv = memcpy(iv, walk->iv, ivsize);
	return 0;
}

static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
				       struct ablkcipher_walk *walk)
{
	walk->src.page = scatterwalk_page(&walk->in);
	walk->src.offset = offset_in_page(walk->in.offset);
	walk->dst.page = scatterwalk_page(&walk->out);
	walk->dst.offset = offset_in_page(walk->out.offset);

	return 0;
}

static int ablkcipher_walk_next(struct ablkcipher_request *req,
				struct ablkcipher_walk *walk)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int alignmask, bsize, n;
	void *src, *dst;
	int err;

	alignmask = crypto_tfm_alg_alignmask(tfm);
	n = walk->total;
	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
		req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return ablkcipher_walk_done(req, walk, -EINVAL);
	}

	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
	src = dst = NULL;

	bsize = min(walk->blocksize, n);
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (n < bsize ||
	    !scatterwalk_aligned(&walk->in, alignmask) ||
	    !scatterwalk_aligned(&walk->out, alignmask)) {
		err = ablkcipher_next_slow(req, walk, bsize, alignmask,
					   &src, &dst);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;

	return ablkcipher_next_fast(req, walk);

set_phys_lowmem:
	if (err >= 0) {
		walk->src.page = virt_to_page(src);
		walk->dst.page = virt_to_page(dst);
		walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
		walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
	}

	return err;
}

static int ablkcipher_walk_first(struct ablkcipher_request *req,
				 struct ablkcipher_walk *walk)
{
	struct crypto_tfm *tfm = req->base.tfm;
	unsigned int alignmask;

	alignmask = crypto_tfm_alg_alignmask(tfm);
	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	walk->nbytes = walk->total;
	if (unlikely(!walk->total))
		return 0;

	walk->iv_buffer = NULL;
	walk->iv = req->info;
	if (unlikely(((unsigned long)walk->iv & alignmask))) {
		int err = ablkcipher_copy_iv(walk, tfm, alignmask);
		if (err)
			return err;
	}

	scatterwalk_start(&walk->in, walk->in.sg);
	scatterwalk_start(&walk->out, walk->out.sg);

	return ablkcipher_walk_next(req, walk);
}

int ablkcipher_walk_phys(struct ablkcipher_request *req,
			 struct ablkcipher_walk *walk)
{
	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
	return ablkcipher_walk_first(req, walk);
}
EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);

static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
			    unsigned int keylen)
{
	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = cipher->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
}

static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
		  unsigned int keylen)
{
	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);

	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
		crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
		return -EINVAL;
	}

	if ((unsigned long)key & alignmask)
		return setkey_unaligned(tfm, key, keylen);

	return cipher->setkey(tfm, key, keylen);
}

static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
					      u32 mask)
{
	return alg->cra_ctxsize;
}

int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
{
	return crypto_ablkcipher_encrypt(&req->creq);
}

int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
{
	return crypto_ablkcipher_decrypt(&req->creq);
}

static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
				      u32 mask)
{
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

	if (alg->ivsize > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	if (!alg->ivsize) {
		crt->givencrypt = skcipher_null_givencrypt;
		crt->givdecrypt = skcipher_null_givdecrypt;
	}
	crt->base = __crypto_ablkcipher_cast(tfm);
	crt->ivsize = alg->ivsize;

	return 0;
}

static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

	seq_printf(m, "type         : ablkcipher\n");
	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
					     "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<default>");
}

const struct crypto_type crypto_ablkcipher_type = {
	.ctxsize = crypto_ablkcipher_ctxsize,
	.init = crypto_init_ablkcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_ablkcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);

static int no_givdecrypt(struct skcipher_givcrypt_request *req)
{
	return -ENOSYS;
}

static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
				      u32 mask)
{
	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;

	if (alg->ivsize > PAGE_SIZE / 8)
		return -EINVAL;

	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
		      alg->setkey : setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;
	crt->givencrypt = alg->givencrypt;
	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
	crt->base = __crypto_ablkcipher_cast(tfm);
	crt->ivsize = alg->ivsize;

	return 0;
}

static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;

	seq_printf(m, "type         : givcipher\n");
	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
					     "yes" : "no");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", ablkcipher->min_keysize);
	seq_printf(m, "max keysize  : %u\n", ablkcipher->max_keysize);
	seq_printf(m, "ivsize       : %u\n", ablkcipher->ivsize);
	seq_printf(m, "geniv        : %s\n", ablkcipher->geniv ?: "<built-in>");
}

const struct crypto_type crypto_givcipher_type = {
	.ctxsize = crypto_ablkcipher_ctxsize,
	.init = crypto_init_givcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_givcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_givcipher_type);

const char *crypto_default_geniv(const struct crypto_alg *alg)
{
	if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	     CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
					 alg->cra_ablkcipher.ivsize) !=
	    alg->cra_blocksize)
		return "chainiv";

	return alg->cra_flags & CRYPTO_ALG_ASYNC ?
	       "eseqiv" : skcipher_default_geniv;
}

static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
{
	struct rtattr *tb[3];
	struct {
		struct rtattr attr;
		struct crypto_attr_type data;
	} ptype;
	struct {
		struct rtattr attr;
		struct crypto_attr_alg data;
	} palg;
	struct crypto_template *tmpl;
	struct crypto_instance *inst;
	struct crypto_alg *larval;
	const char *geniv;
	int err;

	larval = crypto_larval_lookup(alg->cra_driver_name,
				      (type & ~CRYPTO_ALG_TYPE_MASK) |
				      CRYPTO_ALG_TYPE_GIVCIPHER,
				      mask | CRYPTO_ALG_TYPE_MASK);
	err = PTR_ERR(larval);
	if (IS_ERR(larval))
		goto out;

	err = -EAGAIN;
	if (!crypto_is_larval(larval))
		goto drop_larval;

	ptype.attr.rta_len = sizeof(ptype);
	ptype.attr.rta_type = CRYPTOA_TYPE;
	ptype.data.type = type | CRYPTO_ALG_GENIV;
	/* GENIV tells the template that we're making a default geniv. */
	ptype.data.mask = mask | CRYPTO_ALG_GENIV;
	tb[0] = &ptype.attr;

	palg.attr.rta_len = sizeof(palg);
	palg.attr.rta_type = CRYPTOA_ALG;
	/* Must use the exact name to locate ourselves. */
	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
	tb[1] = &palg.attr;

	tb[2] = NULL;

	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	    CRYPTO_ALG_TYPE_BLKCIPHER)
		geniv = alg->cra_blkcipher.geniv;
	else
		geniv = alg->cra_ablkcipher.geniv;

	if (!geniv)
		geniv = crypto_default_geniv(alg);

	tmpl = crypto_lookup_template(geniv);
	err = -ENOENT;
	if (!tmpl)
		goto kill_larval;

	inst = tmpl->alloc(tb);
	err = PTR_ERR(inst);
	if (IS_ERR(inst))
		goto put_tmpl;

	if ((err = crypto_register_instance(tmpl, inst))) {
		tmpl->free(inst);
		goto put_tmpl;
	}

	/* Redo the lookup to use the instance we just registered. */
	err = -EAGAIN;

put_tmpl:
	crypto_tmpl_put(tmpl);
kill_larval:
	crypto_larval_kill(larval);
drop_larval:
	crypto_mod_put(larval);
out:
	crypto_mod_put(alg);
	return err;
}

static struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type,
						 u32 mask)
{
	struct crypto_alg *alg;

	alg = crypto_alg_mod_lookup(name, type, mask);
	if (IS_ERR(alg))
		return alg;

	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	    CRYPTO_ALG_TYPE_GIVCIPHER)
		return alg;

	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	      CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
					  alg->cra_ablkcipher.ivsize))
		return alg;

	crypto_mod_put(alg);
	alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
				    mask & ~CRYPTO_ALG_TESTED);
	if (IS_ERR(alg))
		return alg;

	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	    CRYPTO_ALG_TYPE_GIVCIPHER) {
		if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
			crypto_mod_put(alg);
			alg = ERR_PTR(-ENOENT);
		}
		return alg;
	}

	BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
		 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
					     alg->cra_ablkcipher.ivsize));

	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
}

int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
			 u32 type, u32 mask)
{
	struct crypto_alg *alg;
	int err;

	type = crypto_skcipher_type(type);
	mask = crypto_skcipher_mask(mask);

	alg = crypto_lookup_skcipher(name, type, mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
	crypto_mod_put(alg);
	return err;
}
EXPORT_SYMBOL_GPL(crypto_grab_skcipher);

struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
						  u32 type, u32 mask)
{
	struct crypto_tfm *tfm;
	int err;

	type = crypto_skcipher_type(type);
	mask = crypto_skcipher_mask(mask);

	for (;;) {
		struct crypto_alg *alg;

		alg = crypto_lookup_skcipher(alg_name, type, mask);
		if (IS_ERR(alg)) {
			err = PTR_ERR(alg);
			goto err;
		}

		tfm = __crypto_alloc_tfm(alg, type, mask);
		if (!IS_ERR(tfm))
			return __crypto_ablkcipher_cast(tfm);

		crypto_mod_put(alg);
		err = PTR_ERR(tfm);

err:
		if (err != -EAGAIN)
			break;
		if (signal_pending(current)) {
			err = -EINTR;
			break;
		}
	}

	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);

static int __init skcipher_module_init(void)
{
	skcipher_default_geniv = num_possible_cpus() > 1 ?
				 "eseqiv" : "chainiv";
	return 0;
}

static void skcipher_module_exit(void)
{
}

module_init(skcipher_module_init);
module_exit(skcipher_module_exit);
Commit	Line	Data
b5b7f088 HX	1	/*
b5b7f088 HX	2	* Asynchronous block chaining cipher operations.
c4ede64a	3	*
b5b7f088 HX	4	* This is the asynchronous version of blkcipher.c indicating completion
	5	* via a callback.
	6	*
	7	* Copyright (c) 2006 Herbert Xu <[email protected]>
	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
c4ede64a	11	* Software Foundation; either version 2 of the License, or (at your option)
b5b7f088 HX	12	* any later version.
	13	*
	14	*/
	15
378f4f51	16	#include <crypto/internal/skcipher.h>
0b67fb65	17	#include <linux/cpumask.h>
378f4f51	18	#include <linux/err.h>
b5b7f088	19	#include <linux/init.h>
791b4d5f	20	#include <linux/kernel.h>
b5b7f088	21	#include <linux/module.h>
b9c55aa4 HX	22	#include <linux/rtnetlink.h>
b9c55aa4 HX	23	#include <linux/sched.h>
791b4d5f	24	#include <linux/slab.h>
b5b7f088 HX	25	#include <linux/seq_file.h>
b5b7f088 HX	26
bf06099d DM	27	#include <crypto/scatterwalk.h>
bf06099d DM	28
378f4f51 HX	29	#include "internal.h"
378f4f51 HX	30
0b67fb65 HX	31	static const char *skcipher_default_geniv __read_mostly;
0b67fb65 HX	32
bf06099d DM	33	struct ablkcipher_buffer {
	34	struct list_head entry;
	35	struct scatter_walk dst;
	36	unsigned int len;
	37	void *data;
	38	};
	39
	40	enum {
	41	ABLKCIPHER_WALK_SLOW = 1 << 0,
	42	};
	43
	44	static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
	45	{
	46	scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
	47	}
	48
	49	void __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	}
	59	EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
	60
	61	static 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	*/
	71	static 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
	77	static 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
97	static 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
106	static int ablkcipher_walk_next(struct ablkcipher_request *req,
107	struct ablkcipher_walk *walk);
108
109	int 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
133	err:
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	if (walk->iv_buffer)
145	kfree(walk->iv_buffer);
146
147	return err;
148	}
149	EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
150
151	static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
152	struct ablkcipher_walk *walk,
153	unsigned int bsize,
154	unsigned int alignmask,
155	void src_p, void dst_p)
156	{
157	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
158	struct ablkcipher_buffer *p;
159	void src, dst, *base;
160	unsigned int n;
161
162	n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
163	n += (aligned_bsize * 3 - (alignmask + 1) +
164	(alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
165
166	p = kmalloc(n, GFP_ATOMIC);
167	if (!p)
2716fbf6	168	return ablkcipher_walk_done(req, walk, -ENOMEM);
bf06099d DM	169
	170	base = p + 1;
	171
	172	dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
	173	src = dst = ablkcipher_get_spot(dst, bsize);
	174
	175	p->len = bsize;
	176	p->data = dst;
	177
	178	scatterwalk_copychunks(src, &walk->in, bsize, 0);
	179
	180	ablkcipher_queue_write(walk, p);
	181
	182	walk->nbytes = bsize;
	183	walk->flags \|= ABLKCIPHER_WALK_SLOW;
	184
	185	*src_p = src;
	186	*dst_p = dst;
	187
	188	return 0;
	189	}
	190
	191	static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
	192	struct crypto_tfm *tfm,
	193	unsigned int alignmask)
	194	{
	195	unsigned bs = walk->blocksize;
	196	unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
	197	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
	198	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
	199	(alignmask + 1);
	200	u8 *iv;
	201
	202	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	203	walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
	204	if (!walk->iv_buffer)
	205	return -ENOMEM;
	206
	207	iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
	208	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	209	iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
	210	iv = ablkcipher_get_spot(iv, ivsize);
	211
	212	walk->iv = memcpy(iv, walk->iv, ivsize);
	213	return 0;
	214	}
	215
	216	static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
	217	struct ablkcipher_walk *walk)
	218	{
	219	walk->src.page = scatterwalk_page(&walk->in);
	220	walk->src.offset = offset_in_page(walk->in.offset);
	221	walk->dst.page = scatterwalk_page(&walk->out);
	222	walk->dst.offset = offset_in_page(walk->out.offset);
	223
	224	return 0;
	225	}
	226
	227	static int ablkcipher_walk_next(struct ablkcipher_request *req,
	228	struct ablkcipher_walk *walk)
	229	{
	230	struct crypto_tfm *tfm = req->base.tfm;
	231	unsigned int alignmask, bsize, n;
	232	void src, dst;
233	int err;
234
235	alignmask = crypto_tfm_alg_alignmask(tfm);
236	n = walk->total;
237	if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
238	req->base.flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
239	return ablkcipher_walk_done(req, walk, -EINVAL);
240	}
241
242	walk->flags &= ~ABLKCIPHER_WALK_SLOW;
243	src = dst = NULL;
244
245	bsize = min(walk->blocksize, n);
246	n = scatterwalk_clamp(&walk->in, n);
247	n = scatterwalk_clamp(&walk->out, n);
248
249	if (n < bsize \|\|
250	!scatterwalk_aligned(&walk->in, alignmask) \|\|
251	!scatterwalk_aligned(&walk->out, alignmask)) {
252	err = ablkcipher_next_slow(req, walk, bsize, alignmask,
253	&src, &dst);
254	goto set_phys_lowmem;
255	}
256
257	walk->nbytes = n;
258
259	return ablkcipher_next_fast(req, walk);
260
261	set_phys_lowmem:
262	if (err >= 0) {
263	walk->src.page = virt_to_page(src);
264	walk->dst.page = virt_to_page(dst);
265	walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
266	walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
267	}
268
269	return err;
270	}
271
272	static int ablkcipher_walk_first(struct ablkcipher_request *req,
273	struct ablkcipher_walk *walk)
274	{
275	struct crypto_tfm *tfm = req->base.tfm;
276	unsigned int alignmask;
277
278	alignmask = crypto_tfm_alg_alignmask(tfm);
279	if (WARN_ON_ONCE(in_irq()))
280	return -EDEADLK;
281
282	walk->nbytes = walk->total;
283	if (unlikely(!walk->total))
284	return 0;
285
286	walk->iv_buffer = NULL;
287	walk->iv = req->info;
288	if (unlikely(((unsigned long)walk->iv & alignmask))) {
289	int err = ablkcipher_copy_iv(walk, tfm, alignmask);
290	if (err)
291	return err;
292	}
293
294	scatterwalk_start(&walk->in, walk->in.sg);
295	scatterwalk_start(&walk->out, walk->out.sg);
296
297	return ablkcipher_walk_next(req, walk);
298	}
299
300	int ablkcipher_walk_phys(struct ablkcipher_request *req,
301	struct ablkcipher_walk *walk)
302	{
303	walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
304	return ablkcipher_walk_first(req, walk);
305	}
306	EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
307
791b4d5f HX	308	static int setkey_unaligned(struct crypto_ablkcipher tfm, const u8 key,
791b4d5f HX	309	unsigned int keylen)
ca7c3938 SS	310	{
	311	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
	312	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
	313	int ret;
	314	u8 buffer, alignbuffer;
	315	unsigned long absize;
	316
	317	absize = keylen + alignmask;
	318	buffer = kmalloc(absize, GFP_ATOMIC);
	319	if (!buffer)
	320	return -ENOMEM;
	321
	322	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	323	memcpy(alignbuffer, key, keylen);
	324	ret = cipher->setkey(tfm, alignbuffer, keylen);
06817176	325	memset(alignbuffer, 0, keylen);
ca7c3938 SS	326	kfree(buffer);
	327	return ret;
	328	}
	329
b5b7f088 HX	330	static int setkey(struct crypto_ablkcipher tfm, const u8 key,
	331	unsigned int keylen)
	332	{
	333	struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
ca7c3938	334	unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
b5b7f088 HX	335
	336	if (keylen < cipher->min_keysize \|\| keylen > cipher->max_keysize) {
	337	crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
	338	return -EINVAL;
	339	}
	340
ca7c3938 SS	341	if ((unsigned long)key & alignmask)
	342	return setkey_unaligned(tfm, key, keylen);
	343
b5b7f088 HX	344	return cipher->setkey(tfm, key, keylen);
	345	}
	346
	347	static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
	348	u32 mask)
	349	{
	350	return alg->cra_ctxsize;
	351	}
	352
b9c55aa4 HX	353	int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
	354	{
	355	return crypto_ablkcipher_encrypt(&req->creq);
	356	}
	357
	358	int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
	359	{
	360	return crypto_ablkcipher_decrypt(&req->creq);
	361	}
	362
b5b7f088 HX	363	static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
	364	u32 mask)
	365	{
	366	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	367	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
	368
	369	if (alg->ivsize > PAGE_SIZE / 8)
	370	return -EINVAL;
	371
	372	crt->setkey = setkey;
	373	crt->encrypt = alg->encrypt;
	374	crt->decrypt = alg->decrypt;
b9c55aa4 HX	375	if (!alg->ivsize) {
	376	crt->givencrypt = skcipher_null_givencrypt;
	377	crt->givdecrypt = skcipher_null_givdecrypt;
	378	}
ecfc4329	379	crt->base = __crypto_ablkcipher_cast(tfm);
b5b7f088 HX	380	crt->ivsize = alg->ivsize;
	381
	382	return 0;
	383	}
	384
	385	static void crypto_ablkcipher_show(struct seq_file m, struct crypto_alg alg)
	386	__attribute__ ((unused));
	387	static void crypto_ablkcipher_show(struct seq_file m, struct crypto_alg alg)
	388	{
	389	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
	390
	391	seq_printf(m, "type : ablkcipher\n");
189ed66e HX	392	seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
189ed66e HX	393	"yes" : "no");
b5b7f088 HX	394	seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
	395	seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
	396	seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
	397	seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
23508e11	398	seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
b5b7f088 HX	399	}
	400
	401	const struct crypto_type crypto_ablkcipher_type = {
	402	.ctxsize = crypto_ablkcipher_ctxsize,
	403	.init = crypto_init_ablkcipher_ops,
	404	#ifdef CONFIG_PROC_FS
	405	.show = crypto_ablkcipher_show,
	406	#endif
	407	};
	408	EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
	409
61da88e2 HX	410	static int no_givdecrypt(struct skcipher_givcrypt_request *req)
	411	{
	412	return -ENOSYS;
	413	}
	414
	415	static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
	416	u32 mask)
	417	{
	418	struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
	419	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
	420
	421	if (alg->ivsize > PAGE_SIZE / 8)
	422	return -EINVAL;
	423
ecfc4329 HX	424	crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
ecfc4329 HX	425	alg->setkey : setkey;
61da88e2 HX	426	crt->encrypt = alg->encrypt;
	427	crt->decrypt = alg->decrypt;
	428	crt->givencrypt = alg->givencrypt;
	429	crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
ecfc4329	430	crt->base = __crypto_ablkcipher_cast(tfm);
61da88e2 HX	431	crt->ivsize = alg->ivsize;
	432
	433	return 0;
	434	}
	435
	436	static void crypto_givcipher_show(struct seq_file m, struct crypto_alg alg)
	437	__attribute__ ((unused));
	438	static void crypto_givcipher_show(struct seq_file m, struct crypto_alg alg)
	439	{
	440	struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
	441
	442	seq_printf(m, "type : givcipher\n");
189ed66e HX	443	seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
189ed66e HX	444	"yes" : "no");
61da88e2 HX	445	seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
	446	seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
	447	seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
	448	seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
23508e11	449	seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
61da88e2 HX	450	}
	451
	452	const struct crypto_type crypto_givcipher_type = {
	453	.ctxsize = crypto_ablkcipher_ctxsize,
	454	.init = crypto_init_givcipher_ops,
	455	#ifdef CONFIG_PROC_FS
	456	.show = crypto_givcipher_show,
	457	#endif
	458	};
	459	EXPORT_SYMBOL_GPL(crypto_givcipher_type);
	460
ecfc4329 HX	461	const char crypto_default_geniv(const struct crypto_alg alg)
ecfc4329 HX	462	{
63b5ac28 HX	463	if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	464	CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
	465	alg->cra_ablkcipher.ivsize) !=
	466	alg->cra_blocksize)
	467	return "chainiv";
	468
0b67fb65 HX	469	return alg->cra_flags & CRYPTO_ALG_ASYNC ?
0b67fb65 HX	470	"eseqiv" : skcipher_default_geniv;
ecfc4329 HX	471	}
ecfc4329 HX	472
b9c55aa4 HX	473	static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
	474	{
	475	struct rtattr *tb[3];
	476	struct {
	477	struct rtattr attr;
	478	struct crypto_attr_type data;
	479	} ptype;
	480	struct {
	481	struct rtattr attr;
	482	struct crypto_attr_alg data;
	483	} palg;
	484	struct crypto_template *tmpl;
	485	struct crypto_instance *inst;
	486	struct crypto_alg *larval;
	487	const char *geniv;
	488	int err;
	489
	490	larval = crypto_larval_lookup(alg->cra_driver_name,
435578ae	491	(type & ~CRYPTO_ALG_TYPE_MASK) \|
b9c55aa4	492	CRYPTO_ALG_TYPE_GIVCIPHER,
435578ae	493	mask \| CRYPTO_ALG_TYPE_MASK);
b9c55aa4 HX	494	err = PTR_ERR(larval);
	495	if (IS_ERR(larval))
	496	goto out;
	497
	498	err = -EAGAIN;
	499	if (!crypto_is_larval(larval))
	500	goto drop_larval;
	501
	502	ptype.attr.rta_len = sizeof(ptype);
	503	ptype.attr.rta_type = CRYPTOA_TYPE;
	504	ptype.data.type = type \| CRYPTO_ALG_GENIV;
	505	/* GENIV tells the template that we're making a default geniv. */
	506	ptype.data.mask = mask \| CRYPTO_ALG_GENIV;
	507	tb[0] = &ptype.attr;
	508
	509	palg.attr.rta_len = sizeof(palg);
	510	palg.attr.rta_type = CRYPTOA_ALG;
	511	/* Must use the exact name to locate ourselves. */
	512	memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
	513	tb[1] = &palg.attr;
	514
	515	tb[2] = NULL;
	516
	517	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	518	CRYPTO_ALG_TYPE_BLKCIPHER)
	519	geniv = alg->cra_blkcipher.geniv;
	520	else
	521	geniv = alg->cra_ablkcipher.geniv;
	522
	523	if (!geniv)
	524	geniv = crypto_default_geniv(alg);
	525
	526	tmpl = crypto_lookup_template(geniv);
	527	err = -ENOENT;
	528	if (!tmpl)
	529	goto kill_larval;
	530
	531	inst = tmpl->alloc(tb);
	532	err = PTR_ERR(inst);
	533	if (IS_ERR(inst))
	534	goto put_tmpl;
	535
	536	if ((err = crypto_register_instance(tmpl, inst))) {
	537	tmpl->free(inst);
	538	goto put_tmpl;
	539	}
	540
	541	/* Redo the lookup to use the instance we just registered. */
	542	err = -EAGAIN;
	543
	544	put_tmpl:
	545	crypto_tmpl_put(tmpl);
	546	kill_larval:
	547	crypto_larval_kill(larval);
	548	drop_larval:
	549	crypto_mod_put(larval);
	550	out:
	551	crypto_mod_put(alg);
	552	return err;
	553	}
	554
	555	static struct crypto_alg crypto_lookup_skcipher(const char name, u32 type,
	556	u32 mask)
	557	{
558	struct crypto_alg *alg;
559
560	alg = crypto_alg_mod_lookup(name, type, mask);
561	if (IS_ERR(alg))
562	return alg;
563
564	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
565	CRYPTO_ALG_TYPE_GIVCIPHER)
566	return alg;
567
568	if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
569	CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
570	alg->cra_ablkcipher.ivsize))
571	return alg;
572
b170a137 HX	573	crypto_mod_put(alg);
	574	alg = crypto_alg_mod_lookup(name, type \| CRYPTO_ALG_TESTED,
	575	mask & ~CRYPTO_ALG_TESTED);
	576	if (IS_ERR(alg))
	577	return alg;
	578
	579	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	580	CRYPTO_ALG_TYPE_GIVCIPHER) {
	581	if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
	582	crypto_mod_put(alg);
	583	alg = ERR_PTR(-ENOENT);
	584	}
	585	return alg;
	586	}
	587
	588	BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	589	CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
	590	alg->cra_ablkcipher.ivsize));
	591
b9c55aa4 HX	592	return ERR_PTR(crypto_givcipher_default(alg, type, mask));
	593	}
	594
378f4f51 HX	595	int crypto_grab_skcipher(struct crypto_skcipher_spawn spawn, const char name,
	596	u32 type, u32 mask)
	597	{
	598	struct crypto_alg *alg;
	599	int err;
	600
	601	type = crypto_skcipher_type(type);
	602	mask = crypto_skcipher_mask(mask);
	603
b9c55aa4	604	alg = crypto_lookup_skcipher(name, type, mask);
378f4f51 HX	605	if (IS_ERR(alg))
	606	return PTR_ERR(alg);
	607
	608	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
	609	crypto_mod_put(alg);
	610	return err;
	611	}
	612	EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
	613
b9c55aa4 HX	614	struct crypto_ablkcipher crypto_alloc_ablkcipher(const char alg_name,
	615	u32 type, u32 mask)
	616	{
	617	struct crypto_tfm *tfm;
	618	int err;
	619
	620	type = crypto_skcipher_type(type);
	621	mask = crypto_skcipher_mask(mask);
	622
	623	for (;;) {
	624	struct crypto_alg *alg;
	625
	626	alg = crypto_lookup_skcipher(alg_name, type, mask);
	627	if (IS_ERR(alg)) {
	628	err = PTR_ERR(alg);
	629	goto err;
	630	}
	631
	632	tfm = __crypto_alloc_tfm(alg, type, mask);
	633	if (!IS_ERR(tfm))
	634	return __crypto_ablkcipher_cast(tfm);
	635
	636	crypto_mod_put(alg);
	637	err = PTR_ERR(tfm);
	638
	639	err:
	640	if (err != -EAGAIN)
	641	break;
	642	if (signal_pending(current)) {
	643	err = -EINTR;
	644	break;
	645	}
	646	}
	647
	648	return ERR_PTR(err);
	649	}
	650	EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
0b67fb65 HX	651
	652	static int __init skcipher_module_init(void)
	653	{
	654	skcipher_default_geniv = num_possible_cpus() > 1 ?
	655	"eseqiv" : "chainiv";
	656	return 0;
	657	}
	658
	659	static void skcipher_module_exit(void)
	660	{
	661	}
	662
	663	module_init(skcipher_module_init);
	664	module_exit(skcipher_module_exit);