[mirror_ubuntu-zesty-kernel.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 <herbert@gondor.apana.org.au>
 *
 * 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/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);
}

static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
	if (offset_in_page(start + len) < len)
		return (u8 *)((unsigned long)(start + len) & PAGE_MASK);
	return start;
}

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 * 2 + (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);

	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(struct crypto_tfm *tfm, const u8 *key,
		  unsigned int keylen)
{
	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;

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

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

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

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

	return len;
}

static int crypto_init_blkcipher_ops(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;

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

	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 void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute_used__;
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 <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 <linux/crypto.h>
	18	#include <linux/errno.h>
	19	#include <linux/kernel.h>
5cde0af2 HX	20	#include <linux/module.h>
	21	#include <linux/scatterlist.h>
	22	#include <linux/seq_file.h>
	23	#include <linux/slab.h>
	24	#include <linux/string.h>
	25
	26	#include "internal.h"
	27	#include "scatterwalk.h"
	28
	29	enum {
	30	BLKCIPHER_WALK_PHYS = 1 << 0,
	31	BLKCIPHER_WALK_SLOW = 1 << 1,
	32	BLKCIPHER_WALK_COPY = 1 << 2,
	33	BLKCIPHER_WALK_DIFF = 1 << 3,
	34	};
	35
	36	static int blkcipher_walk_next(struct blkcipher_desc *desc,
	37	struct blkcipher_walk *walk);
	38	static int blkcipher_walk_first(struct blkcipher_desc *desc,
	39	struct blkcipher_walk *walk);
	40
	41	static inline void blkcipher_map_src(struct blkcipher_walk *walk)
	42	{
	43	walk->src.virt.addr = scatterwalk_map(&walk->in, 0);
	44	}
	45
	46	static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
	47	{
	48	walk->dst.virt.addr = scatterwalk_map(&walk->out, 1);
	49	}
	50
	51	static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
	52	{
	53	scatterwalk_unmap(walk->src.virt.addr, 0);
	54	}
	55
	56	static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
	57	{
	58	scatterwalk_unmap(walk->dst.virt.addr, 1);
	59	}
	60
	61	static inline u8 blkcipher_get_spot(u8 start, unsigned int len)
	62	{
	63	if (offset_in_page(start + len) < len)
	64	return (u8 *)((unsigned long)(start + len) & PAGE_MASK);
	65	return start;
	66	}
	67
	68	static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
	69	struct blkcipher_walk *walk,
	70	unsigned int bsize)
	71	{
	72	u8 *addr;
	73	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
	74
	75	addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	76	addr = blkcipher_get_spot(addr, bsize);
	77	scatterwalk_copychunks(addr, &walk->out, bsize, 1);
	78	return bsize;
	79	}
	80
	81	static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
	82	unsigned int n)
	83	{
84	n = walk->nbytes - n;
85
86	if (walk->flags & BLKCIPHER_WALK_COPY) {
87	blkcipher_map_dst(walk);
88	memcpy(walk->dst.virt.addr, walk->page, n);
89	blkcipher_unmap_dst(walk);
90	} else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
91	blkcipher_unmap_src(walk);
92	if (walk->flags & BLKCIPHER_WALK_DIFF)
93	blkcipher_unmap_dst(walk);
94	}
95
96	scatterwalk_advance(&walk->in, n);
97	scatterwalk_advance(&walk->out, n);
98
99	return n;
100	}
101
102	int blkcipher_walk_done(struct blkcipher_desc *desc,
103	struct blkcipher_walk *walk, int err)
104	{
105	struct crypto_blkcipher *tfm = desc->tfm;
106	unsigned int nbytes = 0;
107
108	if (likely(err >= 0)) {
109	unsigned int bsize = crypto_blkcipher_blocksize(tfm);
110	unsigned int n;
111
112	if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
113	n = blkcipher_done_fast(walk, err);
114	else
115	n = blkcipher_done_slow(tfm, walk, bsize);
116
117	nbytes = walk->total - n;
118	err = 0;
119	}
120
121	scatterwalk_done(&walk->in, 0, nbytes);
122	scatterwalk_done(&walk->out, 1, nbytes);
123
124	walk->total = nbytes;
125	walk->nbytes = nbytes;
126
127	if (nbytes) {
128	crypto_yield(desc->flags);
129	return blkcipher_walk_next(desc, walk);
130	}
131
132	if (walk->iv != desc->info)
133	memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
134	if (walk->buffer != walk->page)
135	kfree(walk->buffer);
136	if (walk->page)
137	free_page((unsigned long)walk->page);
138
139	return err;
140	}
141	EXPORT_SYMBOL_GPL(blkcipher_walk_done);
142
143	static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
144	struct blkcipher_walk *walk,
145	unsigned int bsize,
146	unsigned int alignmask)
147	{
148	unsigned int n;
149
150	if (walk->buffer)
151	goto ok;
152
153	walk->buffer = walk->page;
154	if (walk->buffer)
155	goto ok;
156
157	n = bsize * 2 + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
158	walk->buffer = kmalloc(n, GFP_ATOMIC);
159	if (!walk->buffer)
160	return blkcipher_walk_done(desc, walk, -ENOMEM);
161
162	ok:
163	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
164	alignmask + 1);
165	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
166	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr + bsize,
167	bsize);
168
169	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);
170
171	walk->nbytes = bsize;
172	walk->flags \|= BLKCIPHER_WALK_SLOW;
173
174	return 0;
175	}
176
177	static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
178	{
179	u8 *tmp = walk->page;
180
181	blkcipher_map_src(walk);
182	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
183	blkcipher_unmap_src(walk);
184
185	walk->src.virt.addr = tmp;
186	walk->dst.virt.addr = tmp;
187
188	return 0;
189	}
190
191	static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
192	struct blkcipher_walk *walk)
193	{
194	unsigned long diff;
195
196	walk->src.phys.page = scatterwalk_page(&walk->in);
197	walk->src.phys.offset = offset_in_page(walk->in.offset);
198	walk->dst.phys.page = scatterwalk_page(&walk->out);
199	walk->dst.phys.offset = offset_in_page(walk->out.offset);
200
201	if (walk->flags & BLKCIPHER_WALK_PHYS)
202	return 0;
203
204	diff = walk->src.phys.offset - walk->dst.phys.offset;
205	diff \|= walk->src.virt.page - walk->dst.virt.page;
206
207	blkcipher_map_src(walk);
208	walk->dst.virt.addr = walk->src.virt.addr;
209
210	if (diff) {
211	walk->flags \|= BLKCIPHER_WALK_DIFF;
212	blkcipher_map_dst(walk);
213	}
214
215	return 0;
216	}
217
218	static int blkcipher_walk_next(struct blkcipher_desc *desc,
219	struct blkcipher_walk *walk)
220	{
221	struct crypto_blkcipher *tfm = desc->tfm;
222	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
223	unsigned int bsize = crypto_blkcipher_blocksize(tfm);
224	unsigned int n;
225	int err;
226
227	n = walk->total;
228	if (unlikely(n < bsize)) {
229	desc->flags \|= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
230	return blkcipher_walk_done(desc, walk, -EINVAL);
231	}
232
233	walk->flags &= ~(BLKCIPHER_WALK_SLOW \| BLKCIPHER_WALK_COPY \|
234	BLKCIPHER_WALK_DIFF);
235	if (!scatterwalk_aligned(&walk->in, alignmask) \|\|
236	!scatterwalk_aligned(&walk->out, alignmask)) {
237	walk->flags \|= BLKCIPHER_WALK_COPY;
238	if (!walk->page) {
239	walk->page = (void *)__get_free_page(GFP_ATOMIC);
240	if (!walk->page)
241	n = 0;
242	}
243	}
244
245	n = scatterwalk_clamp(&walk->in, n);
246	n = scatterwalk_clamp(&walk->out, n);
247
248	if (unlikely(n < bsize)) {
249	err = blkcipher_next_slow(desc, walk, bsize, alignmask);
250	goto set_phys_lowmem;
251	}
252
253	walk->nbytes = n;
254	if (walk->flags & BLKCIPHER_WALK_COPY) {
255	err = blkcipher_next_copy(walk);
256	goto set_phys_lowmem;
257	}
258
259	return blkcipher_next_fast(desc, walk);
260
261	set_phys_lowmem:
262	if (walk->flags & BLKCIPHER_WALK_PHYS) {
263	walk->src.phys.page = virt_to_page(walk->src.virt.addr);
264	walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
265	walk->src.phys.offset &= PAGE_SIZE - 1;
266	walk->dst.phys.offset &= PAGE_SIZE - 1;
267	}
268	return err;
269	}
270
271	static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
272	struct crypto_blkcipher *tfm,
273	unsigned int alignmask)
274	{
275	unsigned bs = crypto_blkcipher_blocksize(tfm);
276	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
277	unsigned int size = bs * 2 + ivsize + max(bs, ivsize) - (alignmask + 1);
278	u8 *iv;
279
280	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
281	walk->buffer = kmalloc(size, GFP_ATOMIC);
282	if (!walk->buffer)
283	return -ENOMEM;
284
285	iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
286	iv = blkcipher_get_spot(iv, bs) + bs;
287	iv = blkcipher_get_spot(iv, bs) + bs;
288	iv = blkcipher_get_spot(iv, ivsize);
289
290	walk->iv = memcpy(iv, walk->iv, ivsize);
291	return 0;
292	}
293
294	int blkcipher_walk_virt(struct blkcipher_desc *desc,
295	struct blkcipher_walk *walk)
296	{
297	walk->flags &= ~BLKCIPHER_WALK_PHYS;
298	return blkcipher_walk_first(desc, walk);
299	}
300	EXPORT_SYMBOL_GPL(blkcipher_walk_virt);
301
302	int blkcipher_walk_phys(struct blkcipher_desc *desc,
303	struct blkcipher_walk *walk)
304	{
305	walk->flags \|= BLKCIPHER_WALK_PHYS;
306	return blkcipher_walk_first(desc, walk);
307	}
308	EXPORT_SYMBOL_GPL(blkcipher_walk_phys);
309
310	static int blkcipher_walk_first(struct blkcipher_desc *desc,
311	struct blkcipher_walk *walk)
312	{
313	struct crypto_blkcipher *tfm = desc->tfm;
314	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
315
316	walk->nbytes = walk->total;
317	if (unlikely(!walk->total))
318	return 0;
319
320	walk->buffer = NULL;
321	walk->iv = desc->info;
322	if (unlikely(((unsigned long)walk->iv & alignmask))) {
323	int err = blkcipher_copy_iv(walk, tfm, alignmask);
324	if (err)
325	return err;
326	}
327
328	scatterwalk_start(&walk->in, walk->in.sg);
329	scatterwalk_start(&walk->out, walk->out.sg);
330	walk->page = NULL;
331
332	return blkcipher_walk_next(desc, walk);
333	}
334
335	static int setkey(struct crypto_tfm tfm, const u8 key,
336	unsigned int keylen)
337	{
338	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
339
340	if (keylen < cipher->min_keysize \|\| keylen > cipher->max_keysize) {
341	tfm->crt_flags \|= CRYPTO_TFM_RES_BAD_KEY_LEN;
342	return -EINVAL;
343	}
344
345	return cipher->setkey(tfm, key, keylen);
346	}
347
348	static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg)
349	{
350	struct blkcipher_alg *cipher = &alg->cra_blkcipher;
351	unsigned int len = alg->cra_ctxsize;
352
353	if (cipher->ivsize) {
354	len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
355	len += cipher->ivsize;
356	}
357
358	return len;
359	}
360
361	static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm)
362	{
363	struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
364	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
365	unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
366	unsigned long addr;
367
368	if (alg->ivsize > PAGE_SIZE / 8)
369	return -EINVAL;
370
371	crt->setkey = setkey;
372	crt->encrypt = alg->encrypt;
373	crt->decrypt = alg->decrypt;
374
375	addr = (unsigned long)crypto_tfm_ctx(tfm);
376	addr = ALIGN(addr, align);
377	addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
378	crt->iv = (void *)addr;
379
380	return 0;
381	}
382
383	static void crypto_blkcipher_show(struct seq_file m, struct crypto_alg alg)
384	__attribute_used__;
385	static void crypto_blkcipher_show(struct seq_file m, struct crypto_alg alg)
386	{
387	seq_printf(m, "type : blkcipher\n");
388	seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
389	seq_printf(m, "min keysize : %u\n", alg->cra_blkcipher.min_keysize);
390	seq_printf(m, "max keysize : %u\n", alg->cra_blkcipher.max_keysize);
391	seq_printf(m, "ivsize : %u\n", alg->cra_blkcipher.ivsize);
392	}
393
394	const struct crypto_type crypto_blkcipher_type = {
395	.ctxsize = crypto_blkcipher_ctxsize,
396	.init = crypto_init_blkcipher_ops,
397	#ifdef CONFIG_PROC_FS
398	.show = crypto_blkcipher_show,
399	#endif
400	};
401	EXPORT_SYMBOL_GPL(crypto_blkcipher_type);
402
403	MODULE_LICENSE("GPL");
404	MODULE_DESCRIPTION("Generic block chaining cipher type");