[GitHub/mt8127/android_kernel_alcatel_ttab.git] / crypto / pcbc.c

/*
 * PCBC: Propagating Cipher Block Chaining mode
 *
 * Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * Derived from cbc.c
 * - 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 <crypto/algapi.h>
#include <linux/err.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/slab.h>

struct crypto_pcbc_ctx {
	struct crypto_cipher *child;
	void (*xor)(u8 *dst, const u8 *src, unsigned int bs);
};

static int crypto_pcbc_setkey(struct crypto_tfm *parent, const u8 *key,
			      unsigned int keylen)
{
	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(parent);
	struct crypto_cipher *child = ctx->child;
	int err;

	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
				CRYPTO_TFM_REQ_MASK);
	err = crypto_cipher_setkey(child, key, keylen);
	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
			     CRYPTO_TFM_RES_MASK);
	return err;
}

static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
				       struct blkcipher_walk *walk,
				       struct crypto_cipher *tfm,
				       void (*xor)(u8 *, const u8 *,
						   unsigned int))
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		crypto_cipher_alg(tfm)->cia_encrypt;
	int bsize = crypto_cipher_blocksize(tfm);
	unsigned int nbytes = walk->nbytes;
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	u8 *iv = walk->iv;

	do {
		xor(iv, src, bsize);
		fn(crypto_cipher_tfm(tfm), dst, iv);
		memcpy(iv, dst, bsize);
		xor(iv, src, bsize);

		src += bsize;
		dst += bsize;
	} while ((nbytes -= bsize) >= bsize);

	return nbytes;
}

static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
				       struct blkcipher_walk *walk,
				       struct crypto_cipher *tfm,
				       void (*xor)(u8 *, const u8 *,
						   unsigned int))
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		crypto_cipher_alg(tfm)->cia_encrypt;
	int bsize = crypto_cipher_blocksize(tfm);
	unsigned int nbytes = walk->nbytes;
	u8 *src = walk->src.virt.addr;
	u8 *iv = walk->iv;
	u8 tmpbuf[bsize];

	do {
		memcpy(tmpbuf, src, bsize);
		xor(iv, tmpbuf, bsize);
		fn(crypto_cipher_tfm(tfm), src, iv);
		memcpy(iv, src, bsize);
		xor(iv, tmpbuf, bsize);

		src += bsize;
	} while ((nbytes -= bsize) >= bsize);

	memcpy(walk->iv, iv, bsize);

	return nbytes;
}

static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
			       struct scatterlist *dst, struct scatterlist *src,
			       unsigned int nbytes)
{
	struct blkcipher_walk walk;
	struct crypto_blkcipher *tfm = desc->tfm;
	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
	struct crypto_cipher *child = ctx->child;
	void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
		if (walk.src.virt.addr == walk.dst.virt.addr)
			nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
							     xor);
		else
			nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
							     xor);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
				       struct blkcipher_walk *walk,
				       struct crypto_cipher *tfm,
				       void (*xor)(u8 *, const u8 *,
						   unsigned int))
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		crypto_cipher_alg(tfm)->cia_decrypt;
	int bsize = crypto_cipher_blocksize(tfm);
	unsigned int nbytes = walk->nbytes;
	u8 *src = walk->src.virt.addr;
	u8 *dst = walk->dst.virt.addr;
	u8 *iv = walk->iv;

	do {
		fn(crypto_cipher_tfm(tfm), dst, src);
		xor(dst, iv, bsize);
		memcpy(iv, src, bsize);
		xor(iv, dst, bsize);

		src += bsize;
		dst += bsize;
	} while ((nbytes -= bsize) >= bsize);

	memcpy(walk->iv, iv, bsize);

	return nbytes;
}

static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
				       struct blkcipher_walk *walk,
				       struct crypto_cipher *tfm,
				       void (*xor)(u8 *, const u8 *,
						   unsigned int))
{
	void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
		crypto_cipher_alg(tfm)->cia_decrypt;
	int bsize = crypto_cipher_blocksize(tfm);
	unsigned int nbytes = walk->nbytes;
	u8 *src = walk->src.virt.addr;
	u8 *iv = walk->iv;
	u8 tmpbuf[bsize];

	do {
		memcpy(tmpbuf, src, bsize);
		fn(crypto_cipher_tfm(tfm), src, src);
		xor(src, iv, bsize);
		memcpy(iv, tmpbuf, bsize);
		xor(iv, src, bsize);

		src += bsize;
	} while ((nbytes -= bsize) >= bsize);

	memcpy(walk->iv, iv, bsize);

	return nbytes;
}

static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
			       struct scatterlist *dst, struct scatterlist *src,
			       unsigned int nbytes)
{
	struct blkcipher_walk walk;
	struct crypto_blkcipher *tfm = desc->tfm;
	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
	struct crypto_cipher *child = ctx->child;
	void (*xor)(u8 *, const u8 *, unsigned int bs) = ctx->xor;
	int err;

	blkcipher_walk_init(&walk, dst, src, nbytes);
	err = blkcipher_walk_virt(desc, &walk);

	while ((nbytes = walk.nbytes)) {
		if (walk.src.virt.addr == walk.dst.virt.addr)
			nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
							     xor);
		else
			nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
							     xor);
		err = blkcipher_walk_done(desc, &walk, nbytes);
	}

	return err;
}

static void xor_byte(u8 *a, const u8 *b, unsigned int bs)
{
	do {
		*a++ ^= *b++;
	} while (--bs);
}

static void xor_quad(u8 *dst, const u8 *src, unsigned int bs)
{
	u32 *a = (u32 *)dst;
	u32 *b = (u32 *)src;

	do {
		*a++ ^= *b++;
	} while ((bs -= 4));
}

static void xor_64(u8 *a, const u8 *b, unsigned int bs)
{
	((u32 *)a)[0] ^= ((u32 *)b)[0];
	((u32 *)a)[1] ^= ((u32 *)b)[1];
}

static void xor_128(u8 *a, const u8 *b, unsigned int bs)
{
	((u32 *)a)[0] ^= ((u32 *)b)[0];
	((u32 *)a)[1] ^= ((u32 *)b)[1];
	((u32 *)a)[2] ^= ((u32 *)b)[2];
	((u32 *)a)[3] ^= ((u32 *)b)[3];
}

static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);

	switch (crypto_tfm_alg_blocksize(tfm)) {
	case 8:
		ctx->xor = xor_64;
		break;

	case 16:
		ctx->xor = xor_128;
		break;

	default:
		if (crypto_tfm_alg_blocksize(tfm) % 4)
			ctx->xor = xor_byte;
		else
			ctx->xor = xor_quad;
	}

	tfm = crypto_spawn_tfm(spawn);
	if (IS_ERR(tfm))
		return PTR_ERR(tfm);

	ctx->child = crypto_cipher_cast(tfm);
	return 0;
}

static void crypto_pcbc_exit_tfm(struct crypto_tfm *tfm)
{
	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
	crypto_free_cipher(ctx->child);
}

static struct crypto_instance *crypto_pcbc_alloc(void *param, unsigned int len)
{
	struct crypto_instance *inst;
	struct crypto_alg *alg;

	alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
				  CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
	if (IS_ERR(alg))
		return ERR_PTR(PTR_ERR(alg));

	inst = crypto_alloc_instance("pcbc", alg);
	if (IS_ERR(inst))
		goto out_put_alg;

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = &crypto_blkcipher_type;

	if (!(alg->cra_blocksize % 4))
		inst->alg.cra_alignmask |= 3;
	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;

	inst->alg.cra_ctxsize = sizeof(struct crypto_pcbc_ctx);

	inst->alg.cra_init = crypto_pcbc_init_tfm;
	inst->alg.cra_exit = crypto_pcbc_exit_tfm;

	inst->alg.cra_blkcipher.setkey = crypto_pcbc_setkey;
	inst->alg.cra_blkcipher.encrypt = crypto_pcbc_encrypt;
	inst->alg.cra_blkcipher.decrypt = crypto_pcbc_decrypt;

out_put_alg:
	crypto_mod_put(alg);
	return inst;
}

static void crypto_pcbc_free(struct crypto_instance *inst)
{
	crypto_drop_spawn(crypto_instance_ctx(inst));
	kfree(inst);
}

static struct crypto_template crypto_pcbc_tmpl = {
	.name = "pcbc",
	.alloc = crypto_pcbc_alloc,
	.free = crypto_pcbc_free,
	.module = THIS_MODULE,
};

static int __init crypto_pcbc_module_init(void)
{
	return crypto_register_template(&crypto_pcbc_tmpl);
}

static void __exit crypto_pcbc_module_exit(void)
{
	crypto_unregister_template(&crypto_pcbc_tmpl);
}

module_init(crypto_pcbc_module_init);
module_exit(crypto_pcbc_module_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PCBC block cipher algorithm");
Commit	Line	Data
91652be5 DH	1	/*
	2	* PCBC: Propagating Cipher Block Chaining mode
	3	*
	4	* Copyright (C) 2006 Red Hat, Inc. All Rights Reserved.
	5	* Written by David Howells (dhowells@redhat.com)
	6	*
	7	* Derived from cbc.c
	8	* - Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
	9	*
	10	* This program is free software; you can redistribute it and/or modify it
	11	* under the terms of the GNU General Public License as published by the Free
	12	* Software Foundation; either version 2 of the License, or (at your option)
	13	* any later version.
	14	*
	15	*/
	16
	17	#include <crypto/algapi.h>
	18	#include <linux/err.h>
	19	#include <linux/init.h>
	20	#include <linux/kernel.h>
	21	#include <linux/module.h>
	22	#include <linux/scatterlist.h>
	23	#include <linux/slab.h>
	24
	25	struct crypto_pcbc_ctx {
	26	struct crypto_cipher *child;
	27	void (xor)(u8 dst, const u8 *src, unsigned int bs);
	28	};
	29
	30	static int crypto_pcbc_setkey(struct crypto_tfm parent, const u8 key,
	31	unsigned int keylen)
	32	{
	33	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(parent);
	34	struct crypto_cipher *child = ctx->child;
	35	int err;
	36
	37	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
	38	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
	39	CRYPTO_TFM_REQ_MASK);
	40	err = crypto_cipher_setkey(child, key, keylen);
	41	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
	42	CRYPTO_TFM_RES_MASK);
	43	return err;
	44	}
	45
	46	static int crypto_pcbc_encrypt_segment(struct blkcipher_desc *desc,
	47	struct blkcipher_walk *walk,
	48	struct crypto_cipher *tfm,
	49	void (xor)(u8 , const u8 *,
	50	unsigned int))
	51	{
	52	void (fn)(struct crypto_tfm , u8 , const u8 ) =
	53	crypto_cipher_alg(tfm)->cia_encrypt;
	54	int bsize = crypto_cipher_blocksize(tfm);
	55	unsigned int nbytes = walk->nbytes;
	56	u8 *src = walk->src.virt.addr;
	57	u8 *dst = walk->dst.virt.addr;
	58	u8 *iv = walk->iv;
	59
	60	do {
	61	xor(iv, src, bsize);
	62	fn(crypto_cipher_tfm(tfm), dst, iv);
	63	memcpy(iv, dst, bsize);
	64	xor(iv, src, bsize);
65
66	src += bsize;
67	dst += bsize;
68	} while ((nbytes -= bsize) >= bsize);
69
70	return nbytes;
71	}
72
73	static int crypto_pcbc_encrypt_inplace(struct blkcipher_desc *desc,
74	struct blkcipher_walk *walk,
75	struct crypto_cipher *tfm,
76	void (xor)(u8 , const u8 *,
77	unsigned int))
78	{
79	void (fn)(struct crypto_tfm , u8 , const u8 ) =
80	crypto_cipher_alg(tfm)->cia_encrypt;
81	int bsize = crypto_cipher_blocksize(tfm);
82	unsigned int nbytes = walk->nbytes;
83	u8 *src = walk->src.virt.addr;
84	u8 *iv = walk->iv;
85	u8 tmpbuf[bsize];
86
87	do {
88	memcpy(tmpbuf, src, bsize);
89	xor(iv, tmpbuf, bsize);
90	fn(crypto_cipher_tfm(tfm), src, iv);
91	memcpy(iv, src, bsize);
92	xor(iv, tmpbuf, bsize);
93
94	src += bsize;
95	} while ((nbytes -= bsize) >= bsize);
96
97	memcpy(walk->iv, iv, bsize);
98
99	return nbytes;
100	}
101
102	static int crypto_pcbc_encrypt(struct blkcipher_desc *desc,
103	struct scatterlist dst, struct scatterlist src,
104	unsigned int nbytes)
105	{
106	struct blkcipher_walk walk;
107	struct crypto_blkcipher *tfm = desc->tfm;
108	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
109	struct crypto_cipher *child = ctx->child;
110	void (xor)(u8 , const u8 *, unsigned int bs) = ctx->xor;
111	int err;
112
113	blkcipher_walk_init(&walk, dst, src, nbytes);
114	err = blkcipher_walk_virt(desc, &walk);
115
116	while ((nbytes = walk.nbytes)) {
117	if (walk.src.virt.addr == walk.dst.virt.addr)
118	nbytes = crypto_pcbc_encrypt_inplace(desc, &walk, child,
119	xor);
120	else
121	nbytes = crypto_pcbc_encrypt_segment(desc, &walk, child,
122	xor);
123	err = blkcipher_walk_done(desc, &walk, nbytes);
124	}
125
126	return err;
127	}
128
129	static int crypto_pcbc_decrypt_segment(struct blkcipher_desc *desc,
130	struct blkcipher_walk *walk,
131	struct crypto_cipher *tfm,
132	void (xor)(u8 , const u8 *,
133	unsigned int))
134	{
135	void (fn)(struct crypto_tfm , u8 , const u8 ) =
136	crypto_cipher_alg(tfm)->cia_decrypt;
137	int bsize = crypto_cipher_blocksize(tfm);
138	unsigned int nbytes = walk->nbytes;
139	u8 *src = walk->src.virt.addr;
140	u8 *dst = walk->dst.virt.addr;
141	u8 *iv = walk->iv;
142
143	do {
144	fn(crypto_cipher_tfm(tfm), dst, src);
145	xor(dst, iv, bsize);
146	memcpy(iv, src, bsize);
147	xor(iv, dst, bsize);
148
149	src += bsize;
150	dst += bsize;
151	} while ((nbytes -= bsize) >= bsize);
152
153	memcpy(walk->iv, iv, bsize);
154
155	return nbytes;
156	}
157
158	static int crypto_pcbc_decrypt_inplace(struct blkcipher_desc *desc,
159	struct blkcipher_walk *walk,
160	struct crypto_cipher *tfm,
161	void (xor)(u8 , const u8 *,
162	unsigned int))
163	{
164	void (fn)(struct crypto_tfm , u8 , const u8 ) =
165	crypto_cipher_alg(tfm)->cia_decrypt;
166	int bsize = crypto_cipher_blocksize(tfm);
167	unsigned int nbytes = walk->nbytes;
168	u8 *src = walk->src.virt.addr;
169	u8 *iv = walk->iv;
170	u8 tmpbuf[bsize];
171
172	do {
173	memcpy(tmpbuf, src, bsize);
174	fn(crypto_cipher_tfm(tfm), src, src);
175	xor(src, iv, bsize);
176	memcpy(iv, tmpbuf, bsize);
177	xor(iv, src, bsize);
178
179	src += bsize;
180	} while ((nbytes -= bsize) >= bsize);
181
182	memcpy(walk->iv, iv, bsize);
183
184	return nbytes;
185	}
186
187	static int crypto_pcbc_decrypt(struct blkcipher_desc *desc,
188	struct scatterlist dst, struct scatterlist src,
189	unsigned int nbytes)
190	{
191	struct blkcipher_walk walk;
192	struct crypto_blkcipher *tfm = desc->tfm;
193	struct crypto_pcbc_ctx *ctx = crypto_blkcipher_ctx(tfm);
194	struct crypto_cipher *child = ctx->child;
195	void (xor)(u8 , const u8 *, unsigned int bs) = ctx->xor;
196	int err;
197
198	blkcipher_walk_init(&walk, dst, src, nbytes);
199	err = blkcipher_walk_virt(desc, &walk);
200
201	while ((nbytes = walk.nbytes)) {
202	if (walk.src.virt.addr == walk.dst.virt.addr)
203	nbytes = crypto_pcbc_decrypt_inplace(desc, &walk, child,
204	xor);
205	else
206	nbytes = crypto_pcbc_decrypt_segment(desc, &walk, child,
207	xor);
208	err = blkcipher_walk_done(desc, &walk, nbytes);
209	}
210
211	return err;
212	}
213
214	static void xor_byte(u8 a, const u8 b, unsigned int bs)
215	{
216	do {
217	a++ ^= b++;
218	} while (--bs);
219	}
220
221	static void xor_quad(u8 dst, const u8 src, unsigned int bs)
222	{
223	u32 a = (u32 )dst;
224	u32 b = (u32 )src;
225
226	do {
227	a++ ^= b++;
228	} while ((bs -= 4));
229	}
230
231	static void xor_64(u8 a, const u8 b, unsigned int bs)
232	{
233	((u32 )a)[0] ^= ((u32 )b)[0];
234	((u32 )a)[1] ^= ((u32 )b)[1];
235	}
236
237	static void xor_128(u8 a, const u8 b, unsigned int bs)
238	{
239	((u32 )a)[0] ^= ((u32 )b)[0];
240	((u32 )a)[1] ^= ((u32 )b)[1];
241	((u32 )a)[2] ^= ((u32 )b)[2];
242	((u32 )a)[3] ^= ((u32 )b)[3];
243	}
244
245	static int crypto_pcbc_init_tfm(struct crypto_tfm *tfm)
246	{
247	struct crypto_instance inst = (void )tfm->__crt_alg;
248	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
249	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
250
251	switch (crypto_tfm_alg_blocksize(tfm)) {
252	case 8:
253	ctx->xor = xor_64;
254	break;
255
256	case 16:
257	ctx->xor = xor_128;
258	break;
259
260	default:
261	if (crypto_tfm_alg_blocksize(tfm) % 4)
262	ctx->xor = xor_byte;
263	else
264	ctx->xor = xor_quad;
265	}
266
267	tfm = crypto_spawn_tfm(spawn);
268	if (IS_ERR(tfm))
269	return PTR_ERR(tfm);
270
271	ctx->child = crypto_cipher_cast(tfm);
272	return 0;
273	}
274
275	static void crypto_pcbc_exit_tfm(struct crypto_tfm *tfm)
276	{
277	struct crypto_pcbc_ctx *ctx = crypto_tfm_ctx(tfm);
278	crypto_free_cipher(ctx->child);
279	}
280
281	static struct crypto_instance crypto_pcbc_alloc(void param, unsigned int len)
282	{
283	struct crypto_instance *inst;
284	struct crypto_alg *alg;
285
286	alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
287	CRYPTO_ALG_TYPE_MASK \| CRYPTO_ALG_ASYNC);
288	if (IS_ERR(alg))
289	return ERR_PTR(PTR_ERR(alg));
290
291	inst = crypto_alloc_instance("pcbc", alg);
292	if (IS_ERR(inst))
293	goto out_put_alg;
294
295	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
296	inst->alg.cra_priority = alg->cra_priority;
297	inst->alg.cra_blocksize = alg->cra_blocksize;
298	inst->alg.cra_alignmask = alg->cra_alignmask;
299	inst->alg.cra_type = &crypto_blkcipher_type;
300
301	if (!(alg->cra_blocksize % 4))
302	inst->alg.cra_alignmask \|= 3;
303	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
304	inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
305	inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
306
307	inst->alg.cra_ctxsize = sizeof(struct crypto_pcbc_ctx);
308
309	inst->alg.cra_init = crypto_pcbc_init_tfm;
310	inst->alg.cra_exit = crypto_pcbc_exit_tfm;
311
312	inst->alg.cra_blkcipher.setkey = crypto_pcbc_setkey;
313	inst->alg.cra_blkcipher.encrypt = crypto_pcbc_encrypt;
314	inst->alg.cra_blkcipher.decrypt = crypto_pcbc_decrypt;
315
316	out_put_alg:
317	crypto_mod_put(alg);
318	return inst;
319	}
320
321	static void crypto_pcbc_free(struct crypto_instance *inst)
322	{
323	crypto_drop_spawn(crypto_instance_ctx(inst));
324	kfree(inst);
325	}
326
327	static struct crypto_template crypto_pcbc_tmpl = {
328	.name = "pcbc",
329	.alloc = crypto_pcbc_alloc,
330	.free = crypto_pcbc_free,
331	.module = THIS_MODULE,
332	};
333
334	static int __init crypto_pcbc_module_init(void)
335	{
336	return crypto_register_template(&crypto_pcbc_tmpl);
337	}
338
339	static void __exit crypto_pcbc_module_exit(void)
340	{
341	crypto_unregister_template(&crypto_pcbc_tmpl);
342	}
343
344	module_init(crypto_pcbc_module_init);
345	module_exit(crypto_pcbc_module_exit);
346
347	MODULE_LICENSE("GPL");
348	MODULE_DESCRIPTION("PCBC block cipher algorithm");