[linux.git] / crypto / blkcipher.c

/*
 * Block chaining cipher operations.
 * 
 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
 * multiple page boundaries by using temporary blocks.  In user context,
 * the kernel is given a chance to schedule us once per page.
 *
 * 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 <linux/crypto.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>

#include "internal.h"
#include "scatterwalk.h"

enum {
	BLKCIPHER_WALK_PHYS = 1 << 0,
	BLKCIPHER_WALK_SLOW = 1 << 1,
	BLKCIPHER_WALK_COPY = 1 << 2,
	BLKCIPHER_WALK_DIFF = 1 << 3,
};

static int blkcipher_walk_next(struct blkcipher_desc *desc,
			       struct blkcipher_walk *walk);
static int blkcipher_walk_first(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk);

static inline void blkcipher_map_src(struct blkcipher_walk *walk)
{
	walk->src.virt.addr = scatterwalk_map(&walk->in, 0);
}

static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
{
	walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);
}

static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
{
	scatterwalk_unmap(walk->src.virt.addr, 0);
}

static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
{
	scatterwalk_unmap(walk->dst.virt.addr, 1);
}

/* 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 *blkcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
	return start > end_page ? start : end_page;
}

static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
					       struct blkcipher_walk *walk,
					       unsigned int bsize)
{
	u8 *addr;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

	addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	addr = blkcipher_get_spot(addr, bsize);
	scatterwalk_copychunks(addr, &walk->out, bsize, 1);
	return bsize;
}

static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
					       unsigned int n)
{
	n = walk->nbytes - n;

	if (walk->flags & BLKCIPHER_WALK_COPY) {
		blkcipher_map_dst(walk);
		memcpy(walk->dst.virt.addr, walk->page, n);
		blkcipher_unmap_dst(walk);
	} else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
		blkcipher_unmap_src(walk);
		if (walk->flags & BLKCIPHER_WALK_DIFF)
			blkcipher_unmap_dst(walk);
	}

	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);

	return n;
}

int blkcipher_walk_done(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk, int err)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int nbytes = 0;

	if (likely(err >= 0)) {
		unsigned int bsize = crypto_blkcipher_blocksize(tfm);
		unsigned int n;

		if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
			n = blkcipher_done_fast(walk, err);
		else
			n = blkcipher_done_slow(tfm, walk, bsize);

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

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

	walk->total = nbytes;
	walk->nbytes = nbytes;

	if (nbytes) {
		crypto_yield(desc->flags);
		return blkcipher_walk_next(desc, walk);
	}

	if (walk->iv != desc->info)
		memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);

	return err;
}
EXPORT_SYMBOL_GPL(blkcipher_walk_done);

static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
				      struct blkcipher_walk *walk,
				      unsigned int bsize,
				      unsigned int alignmask)
{
	unsigned int n;

	if (walk->buffer)
		goto ok;

	walk->buffer = walk->page;
	if (walk->buffer)
		goto ok;

	n = bsize * 3 - (alignmask + 1) +
	    (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
	walk->buffer = kmalloc(n, GFP_ATOMIC);
	if (!walk->buffer)
		return blkcipher_walk_done(desc, walk, -ENOMEM);

ok:
	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
					  alignmask + 1);
	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,
						 bsize);

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

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

	return 0;
}

static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
{
	u8 *tmp = walk->page;

	blkcipher_map_src(walk);
	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
	blkcipher_unmap_src(walk);

	walk->src.virt.addr = tmp;
	walk->dst.virt.addr = tmp;

	return 0;
}

static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
				      struct blkcipher_walk *walk)
{
	unsigned long diff;

	walk->src.phys.page = scatterwalk_page(&walk->in);
	walk->src.phys.offset = offset_in_page(walk->in.offset);
	walk->dst.phys.page = scatterwalk_page(&walk->out);
	walk->dst.phys.offset = offset_in_page(walk->out.offset);

	if (walk->flags & BLKCIPHER_WALK_PHYS)
		return 0;

	diff = walk->src.phys.offset - walk->dst.phys.offset;
	diff |= walk->src.virt.page - walk->dst.virt.page;

	blkcipher_map_src(walk);
	walk->dst.virt.addr = walk->src.virt.addr;

	if (diff) {
		walk->flags |= BLKCIPHER_WALK_DIFF;
		blkcipher_map_dst(walk);
	}

	return 0;
}

static int blkcipher_walk_next(struct blkcipher_desc *desc,
			       struct blkcipher_walk *walk)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
	unsigned int bsize = crypto_blkcipher_blocksize(tfm);
	unsigned int n;
	int err;

	n = walk->total;
	if (unlikely(n < bsize)) {
		desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return blkcipher_walk_done(desc, walk, -EINVAL);
	}

	walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
			 BLKCIPHER_WALK_DIFF);
	if (!scatterwalk_aligned(&walk->in, alignmask) ||
	    !scatterwalk_aligned(&walk->out, alignmask)) {
		walk->flags |= BLKCIPHER_WALK_COPY;
		if (!walk->page) {
			walk->page = (void *)__get_free_page(GFP_ATOMIC);
			if (!walk->page)
				n = 0;
		}
	}

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

	if (unlikely(n < bsize)) {
		err = blkcipher_next_slow(desc, walk, bsize, alignmask);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;
	if (walk->flags & BLKCIPHER_WALK_COPY) {
		err = blkcipher_next_copy(walk);
		goto set_phys_lowmem;
	}

	return blkcipher_next_fast(desc, walk);

set_phys_lowmem:
	if (walk->flags & BLKCIPHER_WALK_PHYS) {
		walk->src.phys.page = virt_to_page(walk->src.virt.addr);
		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
		walk->src.phys.offset &= PAGE_SIZE - 1;
		walk->dst.phys.offset &= PAGE_SIZE - 1;
	}
	return err;
}

static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
				    struct crypto_blkcipher *tfm,
				    unsigned int alignmask)
{
	unsigned bs = crypto_blkcipher_blocksize(tfm);
	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);
	u8 *iv;

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

	iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	iv = blkcipher_get_spot(iv, bs) + bs;
	iv = blkcipher_get_spot(iv, bs) + bs;
	iv = blkcipher_get_spot(iv, ivsize);

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

int blkcipher_walk_virt(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags &= ~BLKCIPHER_WALK_PHYS;
	return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt);

int blkcipher_walk_phys(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags |= BLKCIPHER_WALK_PHYS;
	return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_phys);

static int blkcipher_walk_first(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

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

	walk->buffer = NULL;
	walk->iv = desc->info;
	if (unlikely(((unsigned long)walk->iv & alignmask))) {
		int err = blkcipher_copy_iv(walk, tfm, alignmask);
		if (err)
			return err;
	}

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

	return blkcipher_walk_next(desc, walk);
}

static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
	unsigned long alignmask = crypto_tfm_alg_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_tfm *tfm, const u8 *key,
		  unsigned int keylen)
{
	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);

	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
		tfm->crt_flags |= 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 int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
			unsigned int keylen)
{
	return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
}

static int async_encrypt(struct ablkcipher_request *req)
{
	struct crypto_tfm *tfm = req->base.tfm;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	struct blkcipher_desc desc = {
		.tfm = __crypto_blkcipher_cast(tfm),
		.info = req->info,
		.flags = req->base.flags,
	};


	return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
}

static int async_decrypt(struct ablkcipher_request *req)
{
	struct crypto_tfm *tfm = req->base.tfm;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	struct blkcipher_desc desc = {
		.tfm = __crypto_blkcipher_cast(tfm),
		.info = req->info,
		.flags = req->base.flags,
	};

	return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
}

static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
					     u32 mask)
{
	struct blkcipher_alg *cipher = &alg->cra_blkcipher;
	unsigned int len = alg->cra_ctxsize;

	type ^= CRYPTO_ALG_ASYNC;
	mask &= CRYPTO_ALG_ASYNC;
	if ((type & mask) && cipher->ivsize) {
		len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
		len += cipher->ivsize;
	}

	return len;
}

static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
{
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

	crt->setkey = async_setkey;
	crt->encrypt = async_encrypt;
	crt->decrypt = async_decrypt;
	crt->ivsize = alg->ivsize;

	return 0;
}

static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
{
	struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
	unsigned long addr;

	crt->setkey = setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;

	addr = (unsigned long)crypto_tfm_ctx(tfm);
	addr = ALIGN(addr, align);
	addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
	crt->iv = (void *)addr;

	return 0;
}

static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

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

	type ^= CRYPTO_ALG_ASYNC;
	mask &= CRYPTO_ALG_ASYNC;
	if (type & mask)
		return crypto_init_blkcipher_ops_sync(tfm);
	else
		return crypto_init_blkcipher_ops_async(tfm);
}

static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	seq_printf(m, "type         : blkcipher\n");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
	seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
	seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
}

const struct crypto_type crypto_blkcipher_type = {
	.ctxsize = crypto_blkcipher_ctxsize,
	.init = crypto_init_blkcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_blkcipher_show,
#endif
};
EXPORT_SYMBOL_GPL(crypto_blkcipher_type);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic block chaining cipher type");
Commit	Line	Data
5cde0af2 HX	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 <[email protected]>
	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 <linux/crypto.h>
	18	#include <linux/errno.h>
fb469840	19	#include <linux/hardirq.h>
5cde0af2	20	#include <linux/kernel.h>
5cde0af2 HX	21	#include <linux/module.h>
	22	#include <linux/scatterlist.h>
	23	#include <linux/seq_file.h>
	24	#include <linux/slab.h>
	25	#include <linux/string.h>
	26
	27	#include "internal.h"
	28	#include "scatterwalk.h"
	29
	30	enum {
	31	BLKCIPHER_WALK_PHYS = 1 << 0,
	32	BLKCIPHER_WALK_SLOW = 1 << 1,
	33	BLKCIPHER_WALK_COPY = 1 << 2,
	34	BLKCIPHER_WALK_DIFF = 1 << 3,
	35	};
	36
	37	static int blkcipher_walk_next(struct blkcipher_desc *desc,
	38	struct blkcipher_walk *walk);
	39	static int blkcipher_walk_first(struct blkcipher_desc *desc,
	40	struct blkcipher_walk *walk);
	41
	42	static inline void blkcipher_map_src(struct blkcipher_walk *walk)
	43	{
	44	walk->src.virt.addr = scatterwalk_map(&walk->in, 0);
	45	}
	46
	47	static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
	48	{
	49	walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);
	50	}
	51
	52	static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
	53	{
	54	scatterwalk_unmap(walk->src.virt.addr, 0);
	55	}
	56
	57	static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
	58	{
	59	scatterwalk_unmap(walk->dst.virt.addr, 1);
	60	}
	61
e4630f9f HX	62	/* Get a spot of the specified length that does not straddle a page.
	63	* The caller needs to ensure that there is enough space for this operation.
	64	*/
5cde0af2 HX	65	static inline u8 blkcipher_get_spot(u8 start, unsigned int len)
5cde0af2 HX	66	{
e4630f9f	67	u8 end_page = (u8 )(((unsigned long)(start + len - 1)) & PAGE_MASK);
32528d0f	68	return start > end_page ? start : end_page;
5cde0af2 HX	69	}
	70
	71	static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
	72	struct blkcipher_walk *walk,
	73	unsigned int bsize)
	74	{
	75	u8 *addr;
	76	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
	77
	78	addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	79	addr = blkcipher_get_spot(addr, bsize);
	80	scatterwalk_copychunks(addr, &walk->out, bsize, 1);
	81	return bsize;
	82	}
	83
	84	static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
	85	unsigned int n)
	86	{
	87	n = walk->nbytes - 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	blkcipher_unmap_src(walk);
	95	if (walk->flags & BLKCIPHER_WALK_DIFF)
	96	blkcipher_unmap_dst(walk);
	97	}
	98
	99	scatterwalk_advance(&walk->in, n);
	100	scatterwalk_advance(&walk->out, n);
	101
	102	return n;
	103	}
	104
	105	int 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 bsize = crypto_blkcipher_blocksize(tfm);
	113	unsigned int n;
	114
	115	if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
	116	n = blkcipher_done_fast(walk, err);
	117	else
	118	n = blkcipher_done_slow(tfm, walk, bsize);
	119
	120	nbytes = walk->total - n;
	121	err = 0;
	122	}
	123
	124	scatterwalk_done(&walk->in, 0, nbytes);
	125	scatterwalk_done(&walk->out, 1, nbytes);
	126
	127	walk->total = nbytes;
	128	walk->nbytes = nbytes;
	129
	130	if (nbytes) {
	131	crypto_yield(desc->flags);
	132	return blkcipher_walk_next(desc, walk);
133	}
134
135	if (walk->iv != desc->info)
136	memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
137	if (walk->buffer != walk->page)
138	kfree(walk->buffer);
139	if (walk->page)
140	free_page((unsigned long)walk->page);
141
142	return err;
143	}
144	EXPORT_SYMBOL_GPL(blkcipher_walk_done);
145
146	static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
147	struct blkcipher_walk *walk,
148	unsigned int bsize,
149	unsigned int alignmask)
150	{
151	unsigned int n;
152
153	if (walk->buffer)
154	goto ok;
155
156	walk->buffer = walk->page;
157	if (walk->buffer)
158	goto ok;
159
e4630f9f HX	160	n = bsize * 3 - (alignmask + 1) +
e4630f9f HX	161	(alignmask & ~(crypto_tfm_ctx_alignment() - 1));
5cde0af2 HX	162	walk->buffer = kmalloc(n, GFP_ATOMIC);
	163	if (!walk->buffer)
	164	return blkcipher_walk_done(desc, walk, -ENOMEM);
	165
	166	ok:
	167	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
	168	alignmask + 1);
	169	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
	170	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,
	171	bsize);
	172
	173	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
	174
	175	walk->nbytes = bsize;
	176	walk->flags \|= BLKCIPHER_WALK_SLOW;
	177
	178	return 0;
	179	}
	180
	181	static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
	182	{
	183	u8 *tmp = walk->page;
	184
	185	blkcipher_map_src(walk);
	186	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
	187	blkcipher_unmap_src(walk);
	188
	189	walk->src.virt.addr = tmp;
	190	walk->dst.virt.addr = tmp;
	191
	192	return 0;
	193	}
	194
	195	static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
	196	struct blkcipher_walk *walk)
	197	{
	198	unsigned long diff;
	199
	200	walk->src.phys.page = scatterwalk_page(&walk->in);
	201	walk->src.phys.offset = offset_in_page(walk->in.offset);
	202	walk->dst.phys.page = scatterwalk_page(&walk->out);
	203	walk->dst.phys.offset = offset_in_page(walk->out.offset);
	204
	205	if (walk->flags & BLKCIPHER_WALK_PHYS)
	206	return 0;
	207
	208	diff = walk->src.phys.offset - walk->dst.phys.offset;
	209	diff \|= walk->src.virt.page - walk->dst.virt.page;
	210
	211	blkcipher_map_src(walk);
	212	walk->dst.virt.addr = walk->src.virt.addr;
	213
	214	if (diff) {
	215	walk->flags \|= BLKCIPHER_WALK_DIFF;
	216	blkcipher_map_dst(walk);
	217	}
	218
	219	return 0;
	220	}
	221
	222	static int blkcipher_walk_next(struct blkcipher_desc *desc,
	223	struct blkcipher_walk *walk)
	224	{
	225	struct crypto_blkcipher *tfm = desc->tfm;
226	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
227	unsigned int bsize = crypto_blkcipher_blocksize(tfm);
228	unsigned int n;
229	int err;
230
231	n = walk->total;
232	if (unlikely(n < bsize)) {
233	desc->flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
234	return blkcipher_walk_done(desc, walk, -EINVAL);
235	}
236
237	walk->flags &= ~(BLKCIPHER_WALK_SLOW \| BLKCIPHER_WALK_COPY \|
238	BLKCIPHER_WALK_DIFF);
239	if (!scatterwalk_aligned(&walk->in, alignmask) \|\|
240	!scatterwalk_aligned(&walk->out, alignmask)) {
241	walk->flags \|= BLKCIPHER_WALK_COPY;
242	if (!walk->page) {
243	walk->page = (void *)__get_free_page(GFP_ATOMIC);
244	if (!walk->page)
245	n = 0;
246	}
247	}
248
249	n = scatterwalk_clamp(&walk->in, n);
250	n = scatterwalk_clamp(&walk->out, n);
251
252	if (unlikely(n < bsize)) {
253	err = blkcipher_next_slow(desc, walk, bsize, alignmask);
254	goto set_phys_lowmem;
255	}
256
257	walk->nbytes = n;
258	if (walk->flags & BLKCIPHER_WALK_COPY) {
259	err = blkcipher_next_copy(walk);
260	goto set_phys_lowmem;
261	}
262
263	return blkcipher_next_fast(desc, walk);
264
265	set_phys_lowmem:
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;
271	}
272	return err;
273	}
274
275	static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
276	struct crypto_blkcipher *tfm,
277	unsigned int alignmask)
278	{
279	unsigned bs = crypto_blkcipher_blocksize(tfm);
280	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
281	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);
282	u8 *iv;
283
284	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
285	walk->buffer = kmalloc(size, GFP_ATOMIC);
286	if (!walk->buffer)
287	return -ENOMEM;
288
289	iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
290	iv = blkcipher_get_spot(iv, bs) + bs;
291	iv = blkcipher_get_spot(iv, bs) + bs;
292	iv = blkcipher_get_spot(iv, ivsize);
293
294	walk->iv = memcpy(iv, walk->iv, ivsize);
295	return 0;
296	}
297
298	int blkcipher_walk_virt(struct blkcipher_desc *desc,
299	struct blkcipher_walk *walk)
300	{
301	walk->flags &= ~BLKCIPHER_WALK_PHYS;
302	return blkcipher_walk_first(desc, walk);
303	}
304	EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
305
306	int blkcipher_walk_phys(struct blkcipher_desc *desc,
307	struct blkcipher_walk *walk)
308	{
309	walk->flags \|= BLKCIPHER_WALK_PHYS;
310	return blkcipher_walk_first(desc, walk);
311	}
312	EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
313
314	static int blkcipher_walk_first(struct blkcipher_desc *desc,
315	struct blkcipher_walk *walk)
316	{
317	struct crypto_blkcipher *tfm = desc->tfm;
318	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
319
fb469840 HX	320	if (WARN_ON_ONCE(in_irq()))
	321	return -EDEADLK;
	322
5cde0af2 HX	323	walk->nbytes = walk->total;
	324	if (unlikely(!walk->total))
	325	return 0;
	326
	327	walk->buffer = NULL;
	328	walk->iv = desc->info;
	329	if (unlikely(((unsigned long)walk->iv & alignmask))) {
	330	int err = blkcipher_copy_iv(walk, tfm, alignmask);
	331	if (err)
	332	return err;
	333	}
	334
	335	scatterwalk_start(&walk->in, walk->in.sg);
	336	scatterwalk_start(&walk->out, walk->out.sg);
	337	walk->page = NULL;
	338
	339	return blkcipher_walk_next(desc, walk);
	340	}
	341
ca7c3938 SS	342	static int setkey_unaligned(struct crypto_tfm tfm, const u8 key, unsigned int keylen)
	343	{
	344	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
	345	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
	346	int ret;
	347	u8 buffer, alignbuffer;
	348	unsigned long absize;
	349
	350	absize = keylen + alignmask;
	351	buffer = kmalloc(absize, GFP_ATOMIC);
	352	if (!buffer)
	353	return -ENOMEM;
	354
	355	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	356	memcpy(alignbuffer, key, keylen);
	357	ret = cipher->setkey(tfm, alignbuffer, keylen);
06817176	358	memset(alignbuffer, 0, keylen);
ca7c3938 SS	359	kfree(buffer);
	360	return ret;
	361	}
	362
5cde0af2 HX	363	static int setkey(struct crypto_tfm tfm, const u8 key,
	364	unsigned int keylen)
	365	{
	366	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
ca7c3938	367	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
5cde0af2 HX	368
	369	if (keylen < cipher->min_keysize \|\| keylen > cipher->max_keysize) {
	370	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
	371	return -EINVAL;
	372	}
	373
ca7c3938 SS	374	if ((unsigned long)key & alignmask)
	375	return setkey_unaligned(tfm, key, keylen);
	376
5cde0af2 HX	377	return cipher->setkey(tfm, key, keylen);
	378	}
	379
32e3983f HX	380	static int async_setkey(struct crypto_ablkcipher tfm, const u8 key,
	381	unsigned int keylen)
	382	{
	383	return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
	384	}
	385
	386	static int async_encrypt(struct ablkcipher_request *req)
	387	{
	388	struct crypto_tfm *tfm = req->base.tfm;
	389	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	390	struct blkcipher_desc desc = {
	391	.tfm = __crypto_blkcipher_cast(tfm),
	392	.info = req->info,
	393	.flags = req->base.flags,
	394	};
	395
	396
	397	return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
	398	}
	399
	400	static int async_decrypt(struct ablkcipher_request *req)
	401	{
	402	struct crypto_tfm *tfm = req->base.tfm;
	403	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	404	struct blkcipher_desc desc = {
	405	.tfm = __crypto_blkcipher_cast(tfm),
	406	.info = req->info,
	407	.flags = req->base.flags,
	408	};
	409
	410	return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
	411	}
	412
27d2a330 HX	413	static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
27d2a330 HX	414	u32 mask)
5cde0af2 HX	415	{
	416	struct blkcipher_alg *cipher = &alg->cra_blkcipher;
	417	unsigned int len = alg->cra_ctxsize;
	418
32e3983f HX	419	type ^= CRYPTO_ALG_ASYNC;
	420	mask &= CRYPTO_ALG_ASYNC;
	421	if ((type & mask) && cipher->ivsize) {
5cde0af2 HX	422	len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
	423	len += cipher->ivsize;
	424	}
	425
	426	return len;
	427	}
	428
32e3983f HX	429	static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
	430	{
	431	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
	432	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	433
	434	crt->setkey = async_setkey;
	435	crt->encrypt = async_encrypt;
	436	crt->decrypt = async_decrypt;
	437	crt->ivsize = alg->ivsize;
	438
	439	return 0;
	440	}
	441
	442	static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
5cde0af2 HX	443	{
	444	struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
	445	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	446	unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
	447	unsigned long addr;
	448
5cde0af2 HX	449	crt->setkey = setkey;
	450	crt->encrypt = alg->encrypt;
	451	crt->decrypt = alg->decrypt;
	452
	453	addr = (unsigned long)crypto_tfm_ctx(tfm);
	454	addr = ALIGN(addr, align);
	455	addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
	456	crt->iv = (void *)addr;
	457
	458	return 0;
	459	}
	460
32e3983f HX	461	static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
	462	{
	463	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	464
	465	if (alg->ivsize > PAGE_SIZE / 8)
	466	return -EINVAL;
	467
	468	type ^= CRYPTO_ALG_ASYNC;
	469	mask &= CRYPTO_ALG_ASYNC;
	470	if (type & mask)
	471	return crypto_init_blkcipher_ops_sync(tfm);
	472	else
	473	return crypto_init_blkcipher_ops_async(tfm);
	474	}
	475
5cde0af2	476	static void crypto_blkcipher_show(struct seq_file m, struct crypto_alg alg)
03f5d8ce	477	__attribute__ ((unused));
5cde0af2 HX	478	static void crypto_blkcipher_show(struct seq_file m, struct crypto_alg alg)
	479	{
	480	seq_printf(m, "type : blkcipher\n");
	481	seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
	482	seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
	483	seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
	484	seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
	485	}
	486
	487	const struct crypto_type crypto_blkcipher_type = {
	488	.ctxsize = crypto_blkcipher_ctxsize,
	489	.init = crypto_init_blkcipher_ops,
	490	#ifdef CONFIG_PROC_FS
	491	.show = crypto_blkcipher_show,
	492	#endif
	493	};
	494	EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
	495
	496	MODULE_LICENSE("GPL");
	497	MODULE_DESCRIPTION("Generic block chaining cipher type");