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v3.1
 
  1/* LRW: as defined by Cyril Guyot in
  2 *	http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
  3 *
  4 * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
  5 *
  6 * Based om ecb.c
  7 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
  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
 11 * Software Foundation; either version 2 of the License, or (at your option)
 12 * any later version.
 13 */
 14/* This implementation is checked against the test vectors in the above
 15 * document and by a test vector provided by Ken Buchanan at
 16 * http://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
 17 *
 18 * The test vectors are included in the testing module tcrypt.[ch] */
 19#include <crypto/algapi.h>
 
 
 20#include <linux/err.h>
 21#include <linux/init.h>
 22#include <linux/kernel.h>
 23#include <linux/module.h>
 24#include <linux/scatterlist.h>
 25#include <linux/slab.h>
 26
 27#include <crypto/b128ops.h>
 28#include <crypto/gf128mul.h>
 29
 30struct priv {
 31	struct crypto_cipher *child;
 32	/* optimizes multiplying a random (non incrementing, as at the
 
 
 
 
 33	 * start of a new sector) value with key2, we could also have
 34	 * used 4k optimization tables or no optimization at all. In the
 35	 * latter case we would have to store key2 here */
 
 36	struct gf128mul_64k *table;
 37	/* stores:
 
 
 38	 *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
 39	 *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
 40	 *  key2*{ 0,0,...1,1,1,1,1 }, etc
 41	 * needed for optimized multiplication of incrementing values
 42	 * with key2 */
 
 43	be128 mulinc[128];
 44};
 45
 46static inline void setbit128_bbe(void *b, int bit)
 
 
 
 
 
 47{
 48	__set_bit(bit ^ (0x80 -
 49#ifdef __BIG_ENDIAN
 50			 BITS_PER_LONG
 51#else
 52			 BITS_PER_BYTE
 53#endif
 54			), b);
 55}
 56
 57static int setkey(struct crypto_tfm *parent, const u8 *key,
 58		  unsigned int keylen)
 59{
 60	struct priv *ctx = crypto_tfm_ctx(parent);
 61	struct crypto_cipher *child = ctx->child;
 62	int err, i;
 
 63	be128 tmp = { 0 };
 64	int bsize = crypto_cipher_blocksize(child);
 65
 66	crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 67	crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
 68				       CRYPTO_TFM_REQ_MASK);
 69	if ((err = crypto_cipher_setkey(child, key, keylen - bsize)))
 
 70		return err;
 71	crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
 72				     CRYPTO_TFM_RES_MASK);
 73
 74	if (ctx->table)
 75		gf128mul_free_64k(ctx->table);
 76
 77	/* initialize multiplication table for Key2 */
 78	ctx->table = gf128mul_init_64k_bbe((be128 *)(key + keylen - bsize));
 79	if (!ctx->table)
 80		return -ENOMEM;
 81
 82	/* initialize optimization table */
 83	for (i = 0; i < 128; i++) {
 84		setbit128_bbe(&tmp, i);
 85		ctx->mulinc[i] = tmp;
 86		gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
 87	}
 88
 89	return 0;
 90}
 91
 92struct sinfo {
 93	be128 t;
 94	struct crypto_tfm *tfm;
 95	void (*fn)(struct crypto_tfm *, u8 *, const u8 *);
 96};
 97
 98static inline void inc(be128 *iv)
 99{
100	be64_add_cpu(&iv->b, 1);
101	if (!iv->b)
102		be64_add_cpu(&iv->a, 1);
103}
104
105static inline void lrw_round(struct sinfo *s, void *dst, const void *src)
106{
107	be128_xor(dst, &s->t, src);		/* PP <- T xor P */
108	s->fn(s->tfm, dst, dst);		/* CC <- E(Key2,PP) */
109	be128_xor(dst, dst, &s->t);		/* C <- T xor CC */
110}
111
112/* this returns the number of consequative 1 bits starting
113 * from the right, get_index128(00 00 00 00 00 00 ... 00 00 10 FB) = 2 */
114static inline int get_index128(be128 *block)
115{
116	int x;
117	__be32 *p = (__be32 *) block;
118
119	for (p += 3, x = 0; x < 128; p--, x += 32) {
120		u32 val = be32_to_cpup(p);
121
122		if (!~val)
123			continue;
 
124
125		return x + ffz(val);
 
126	}
127
128	return x;
 
 
 
 
 
129}
130
131static int crypt(struct blkcipher_desc *d,
132		 struct blkcipher_walk *w, struct priv *ctx,
133		 void (*fn)(struct crypto_tfm *, u8 *, const u8 *))
 
 
 
 
134{
 
 
 
 
 
 
 
 
135	int err;
136	unsigned int avail;
137	const int bs = crypto_cipher_blocksize(ctx->child);
138	struct sinfo s = {
139		.tfm = crypto_cipher_tfm(ctx->child),
140		.fn = fn
141	};
142	be128 *iv;
143	u8 *wsrc;
144	u8 *wdst;
145
146	err = blkcipher_walk_virt(d, w);
147	if (!(avail = w->nbytes))
148		return err;
149
150	wsrc = w->src.virt.addr;
151	wdst = w->dst.virt.addr;
152
153	/* calculate first value of T */
154	iv = (be128 *)w->iv;
155	s.t = *iv;
156
157	/* T <- I*Key2 */
158	gf128mul_64k_bbe(&s.t, ctx->table);
 
 
 
 
 
 
 
 
159
160	goto first;
 
161
162	for (;;) {
163		do {
 
 
164			/* T <- I*Key2, using the optimization
165			 * discussed in the specification */
166			be128_xor(&s.t, &s.t, &ctx->mulinc[get_index128(iv)]);
167			inc(iv);
168
169first:
170			lrw_round(&s, wdst, wsrc);
171
172			wsrc += bs;
173			wdst += bs;
174		} while ((avail -= bs) >= bs);
175
176		err = blkcipher_walk_done(d, w, avail);
177		if (!(avail = w->nbytes))
178			break;
 
 
 
179
180		wsrc = w->src.virt.addr;
181		wdst = w->dst.virt.addr;
182	}
183
184	return err;
185}
186
187static int encrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
188		   struct scatterlist *src, unsigned int nbytes)
189{
190	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
191	struct blkcipher_walk w;
192
193	blkcipher_walk_init(&w, dst, src, nbytes);
194	return crypt(desc, &w, ctx,
195		     crypto_cipher_alg(ctx->child)->cia_encrypt);
196}
197
198static int decrypt(struct blkcipher_desc *desc, struct scatterlist *dst,
199		   struct scatterlist *src, unsigned int nbytes)
200{
201	struct priv *ctx = crypto_blkcipher_ctx(desc->tfm);
202	struct blkcipher_walk w;
203
204	blkcipher_walk_init(&w, dst, src, nbytes);
205	return crypt(desc, &w, ctx,
206		     crypto_cipher_alg(ctx->child)->cia_decrypt);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
207}
208
209static int init_tfm(struct crypto_tfm *tfm)
210{
211	struct crypto_cipher *cipher;
212	struct crypto_instance *inst = (void *)tfm->__crt_alg;
213	struct crypto_spawn *spawn = crypto_instance_ctx(inst);
214	struct priv *ctx = crypto_tfm_ctx(tfm);
215	u32 *flags = &tfm->crt_flags;
 
 
 
216
217	cipher = crypto_spawn_cipher(spawn);
 
 
 
 
 
 
 
218	if (IS_ERR(cipher))
219		return PTR_ERR(cipher);
220
221	if (crypto_cipher_blocksize(cipher) != 16) {
222		*flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
223		return -EINVAL;
224	}
225
226	ctx->child = cipher;
 
 
 
 
227	return 0;
228}
229
230static void exit_tfm(struct crypto_tfm *tfm)
231{
232	struct priv *ctx = crypto_tfm_ctx(tfm);
 
233	if (ctx->table)
234		gf128mul_free_64k(ctx->table);
235	crypto_free_cipher(ctx->child);
236}
237
238static struct crypto_instance *alloc(struct rtattr **tb)
239{
240	struct crypto_instance *inst;
241	struct crypto_alg *alg;
 
 
 
 
 
 
 
 
 
 
242	int err;
243
244	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
245	if (err)
246		return ERR_PTR(err);
 
 
 
 
247
248	alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
249				  CRYPTO_ALG_TYPE_MASK);
250	if (IS_ERR(alg))
251		return ERR_CAST(alg);
252
253	inst = crypto_alloc_instance("lrw", alg);
254	if (IS_ERR(inst))
255		goto out_put_alg;
256
257	inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
258	inst->alg.cra_priority = alg->cra_priority;
259	inst->alg.cra_blocksize = alg->cra_blocksize;
 
 
 
 
 
 
 
 
 
260
261	if (alg->cra_alignmask < 7) inst->alg.cra_alignmask = 7;
262	else inst->alg.cra_alignmask = alg->cra_alignmask;
263	inst->alg.cra_type = &crypto_blkcipher_type;
264
265	if (!(alg->cra_blocksize % 4))
266		inst->alg.cra_alignmask |= 3;
267	inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
268	inst->alg.cra_blkcipher.min_keysize =
269		alg->cra_cipher.cia_min_keysize + alg->cra_blocksize;
270	inst->alg.cra_blkcipher.max_keysize =
271		alg->cra_cipher.cia_max_keysize + alg->cra_blocksize;
272
273	inst->alg.cra_ctxsize = sizeof(struct priv);
 
 
274
275	inst->alg.cra_init = init_tfm;
276	inst->alg.cra_exit = exit_tfm;
277
278	inst->alg.cra_blkcipher.setkey = setkey;
279	inst->alg.cra_blkcipher.encrypt = encrypt;
280	inst->alg.cra_blkcipher.decrypt = decrypt;
 
281
282out_put_alg:
283	crypto_mod_put(alg);
284	return inst;
285}
286
287static void free(struct crypto_instance *inst)
288{
289	crypto_drop_spawn(crypto_instance_ctx(inst));
290	kfree(inst);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
291}
292
293static struct crypto_template crypto_tmpl = {
294	.name = "lrw",
295	.alloc = alloc,
296	.free = free,
297	.module = THIS_MODULE,
298};
299
300static int __init crypto_module_init(void)
301{
302	return crypto_register_template(&crypto_tmpl);
303}
304
305static void __exit crypto_module_exit(void)
306{
307	crypto_unregister_template(&crypto_tmpl);
308}
309
310module_init(crypto_module_init);
311module_exit(crypto_module_exit);
312
313MODULE_LICENSE("GPL");
314MODULE_DESCRIPTION("LRW block cipher mode");
v6.9.4
  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/* LRW: as defined by Cyril Guyot in
  3 *	http://grouper.ieee.org/groups/1619/email/pdf00017.pdf
  4 *
  5 * Copyright (c) 2006 Rik Snel <rsnel@cube.dyndns.org>
  6 *
  7 * Based on ecb.c
  8 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 
 
 
 
 
  9 */
 10/* This implementation is checked against the test vectors in the above
 11 * document and by a test vector provided by Ken Buchanan at
 12 * https://www.mail-archive.com/stds-p1619@listserv.ieee.org/msg00173.html
 13 *
 14 * The test vectors are included in the testing module tcrypt.[ch] */
 15
 16#include <crypto/internal/skcipher.h>
 17#include <crypto/scatterwalk.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#include <crypto/b128ops.h>
 26#include <crypto/gf128mul.h>
 27
 28#define LRW_BLOCK_SIZE 16
 29
 30struct lrw_tfm_ctx {
 31	struct crypto_skcipher *child;
 32
 33	/*
 34	 * optimizes multiplying a random (non incrementing, as at the
 35	 * start of a new sector) value with key2, we could also have
 36	 * used 4k optimization tables or no optimization at all. In the
 37	 * latter case we would have to store key2 here
 38	 */
 39	struct gf128mul_64k *table;
 40
 41	/*
 42	 * stores:
 43	 *  key2*{ 0,0,...0,0,0,0,1 }, key2*{ 0,0,...0,0,0,1,1 },
 44	 *  key2*{ 0,0,...0,0,1,1,1 }, key2*{ 0,0,...0,1,1,1,1 }
 45	 *  key2*{ 0,0,...1,1,1,1,1 }, etc
 46	 * needed for optimized multiplication of incrementing values
 47	 * with key2
 48	 */
 49	be128 mulinc[128];
 50};
 51
 52struct lrw_request_ctx {
 53	be128 t;
 54	struct skcipher_request subreq;
 55};
 56
 57static inline void lrw_setbit128_bbe(void *b, int bit)
 58{
 59	__set_bit(bit ^ (0x80 -
 60#ifdef __BIG_ENDIAN
 61			 BITS_PER_LONG
 62#else
 63			 BITS_PER_BYTE
 64#endif
 65			), b);
 66}
 67
 68static int lrw_setkey(struct crypto_skcipher *parent, const u8 *key,
 69		      unsigned int keylen)
 70{
 71	struct lrw_tfm_ctx *ctx = crypto_skcipher_ctx(parent);
 72	struct crypto_skcipher *child = ctx->child;
 73	int err, bsize = LRW_BLOCK_SIZE;
 74	const u8 *tweak = key + keylen - bsize;
 75	be128 tmp = { 0 };
 76	int i;
 77
 78	crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
 79	crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
 80					 CRYPTO_TFM_REQ_MASK);
 81	err = crypto_skcipher_setkey(child, key, keylen - bsize);
 82	if (err)
 83		return err;
 
 
 84
 85	if (ctx->table)
 86		gf128mul_free_64k(ctx->table);
 87
 88	/* initialize multiplication table for Key2 */
 89	ctx->table = gf128mul_init_64k_bbe((be128 *)tweak);
 90	if (!ctx->table)
 91		return -ENOMEM;
 92
 93	/* initialize optimization table */
 94	for (i = 0; i < 128; i++) {
 95		lrw_setbit128_bbe(&tmp, i);
 96		ctx->mulinc[i] = tmp;
 97		gf128mul_64k_bbe(&ctx->mulinc[i], ctx->table);
 98	}
 99
100	return 0;
101}
102
103/*
104 * Returns the number of trailing '1' bits in the words of the counter, which is
105 * represented by 4 32-bit words, arranged from least to most significant.
106 * At the same time, increments the counter by one.
107 *
108 * For example:
109 *
110 * u32 counter[4] = { 0xFFFFFFFF, 0x1, 0x0, 0x0 };
111 * int i = lrw_next_index(&counter);
112 * // i == 33, counter == { 0x0, 0x2, 0x0, 0x0 }
113 */
114static int lrw_next_index(u32 *counter)
 
 
 
 
 
 
 
 
 
 
 
115{
116	int i, res = 0;
 
 
 
 
117
118	for (i = 0; i < 4; i++) {
119		if (counter[i] + 1 != 0)
120			return res + ffz(counter[i]++);
121
122		counter[i] = 0;
123		res += 32;
124	}
125
126	/*
127	 * If we get here, then x == 128 and we are incrementing the counter
128	 * from all ones to all zeros. This means we must return index 127, i.e.
129	 * the one corresponding to key2*{ 1,...,1 }.
130	 */
131	return 127;
132}
133
134/*
135 * We compute the tweak masks twice (both before and after the ECB encryption or
136 * decryption) to avoid having to allocate a temporary buffer and/or make
137 * mutliple calls to the 'ecb(..)' instance, which usually would be slower than
138 * just doing the lrw_next_index() calls again.
139 */
140static int lrw_xor_tweak(struct skcipher_request *req, bool second_pass)
141{
142	const int bs = LRW_BLOCK_SIZE;
143	struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
144	const struct lrw_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
145	struct lrw_request_ctx *rctx = skcipher_request_ctx(req);
146	be128 t = rctx->t;
147	struct skcipher_walk w;
148	__be32 *iv;
149	u32 counter[4];
150	int err;
 
 
 
 
 
 
 
 
 
151
152	if (second_pass) {
153		req = &rctx->subreq;
154		/* set to our TFM to enforce correct alignment: */
155		skcipher_request_set_tfm(req, tfm);
156	}
 
157
158	err = skcipher_walk_virt(&w, req, false);
159	if (err)
160		return err;
161
162	iv = (__be32 *)w.iv;
163	counter[0] = be32_to_cpu(iv[3]);
164	counter[1] = be32_to_cpu(iv[2]);
165	counter[2] = be32_to_cpu(iv[1]);
166	counter[3] = be32_to_cpu(iv[0]);
167
168	while (w.nbytes) {
169		unsigned int avail = w.nbytes;
170		be128 *wsrc;
171		be128 *wdst;
172
173		wsrc = w.src.virt.addr;
174		wdst = w.dst.virt.addr;
175
 
176		do {
177			be128_xor(wdst++, &t, wsrc++);
178
179			/* T <- I*Key2, using the optimization
180			 * discussed in the specification */
181			be128_xor(&t, &t,
182				  &ctx->mulinc[lrw_next_index(counter)]);
 
 
 
 
 
 
183		} while ((avail -= bs) >= bs);
184
185		if (second_pass && w.nbytes == w.total) {
186			iv[0] = cpu_to_be32(counter[3]);
187			iv[1] = cpu_to_be32(counter[2]);
188			iv[2] = cpu_to_be32(counter[1]);
189			iv[3] = cpu_to_be32(counter[0]);
190		}
191
192		err = skcipher_walk_done(&w, avail);
 
193	}
194
195	return err;
196}
197
198static int lrw_xor_tweak_pre(struct skcipher_request *req)
 
199{
200	return lrw_xor_tweak(req, false);
201}
202
203static int lrw_xor_tweak_post(struct skcipher_request *req)
204{
205	return lrw_xor_tweak(req, true);
206}
207
208static void lrw_crypt_done(void *data, int err)
 
209{
210	struct skcipher_request *req = data;
 
211
212	if (!err) {
213		struct lrw_request_ctx *rctx = skcipher_request_ctx(req);
214
215		rctx->subreq.base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
216		err = lrw_xor_tweak_post(req);
217	}
218
219	skcipher_request_complete(req, err);
220}
221
222static void lrw_init_crypt(struct skcipher_request *req)
223{
224	const struct lrw_tfm_ctx *ctx =
225		crypto_skcipher_ctx(crypto_skcipher_reqtfm(req));
226	struct lrw_request_ctx *rctx = skcipher_request_ctx(req);
227	struct skcipher_request *subreq = &rctx->subreq;
228
229	skcipher_request_set_tfm(subreq, ctx->child);
230	skcipher_request_set_callback(subreq, req->base.flags, lrw_crypt_done,
231				      req);
232	/* pass req->iv as IV (will be used by xor_tweak, ECB will ignore it) */
233	skcipher_request_set_crypt(subreq, req->dst, req->dst,
234				   req->cryptlen, req->iv);
235
236	/* calculate first value of T */
237	memcpy(&rctx->t, req->iv, sizeof(rctx->t));
238
239	/* T <- I*Key2 */
240	gf128mul_64k_bbe(&rctx->t, ctx->table);
241}
242
243static int lrw_encrypt(struct skcipher_request *req)
244{
245	struct lrw_request_ctx *rctx = skcipher_request_ctx(req);
246	struct skcipher_request *subreq = &rctx->subreq;
247
248	lrw_init_crypt(req);
249	return lrw_xor_tweak_pre(req) ?:
250		crypto_skcipher_encrypt(subreq) ?:
251		lrw_xor_tweak_post(req);
252}
253
254static int lrw_decrypt(struct skcipher_request *req)
255{
256	struct lrw_request_ctx *rctx = skcipher_request_ctx(req);
257	struct skcipher_request *subreq = &rctx->subreq;
258
259	lrw_init_crypt(req);
260	return lrw_xor_tweak_pre(req) ?:
261		crypto_skcipher_decrypt(subreq) ?:
262		lrw_xor_tweak_post(req);
263}
264
265static int lrw_init_tfm(struct crypto_skcipher *tfm)
266{
267	struct skcipher_instance *inst = skcipher_alg_instance(tfm);
268	struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
269	struct lrw_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
270	struct crypto_skcipher *cipher;
271
272	cipher = crypto_spawn_skcipher(spawn);
273	if (IS_ERR(cipher))
274		return PTR_ERR(cipher);
275
 
 
 
 
 
276	ctx->child = cipher;
277
278	crypto_skcipher_set_reqsize(tfm, crypto_skcipher_reqsize(cipher) +
279					 sizeof(struct lrw_request_ctx));
280
281	return 0;
282}
283
284static void lrw_exit_tfm(struct crypto_skcipher *tfm)
285{
286	struct lrw_tfm_ctx *ctx = crypto_skcipher_ctx(tfm);
287
288	if (ctx->table)
289		gf128mul_free_64k(ctx->table);
290	crypto_free_skcipher(ctx->child);
291}
292
293static void lrw_free_instance(struct skcipher_instance *inst)
294{
295	crypto_drop_skcipher(skcipher_instance_ctx(inst));
296	kfree(inst);
297}
298
299static int lrw_create(struct crypto_template *tmpl, struct rtattr **tb)
300{
301	struct crypto_skcipher_spawn *spawn;
302	struct skcipher_alg_common *alg;
303	struct skcipher_instance *inst;
304	const char *cipher_name;
305	char ecb_name[CRYPTO_MAX_ALG_NAME];
306	u32 mask;
307	int err;
308
309	err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
310	if (err)
311		return err;
312
313	cipher_name = crypto_attr_alg_name(tb[1]);
314	if (IS_ERR(cipher_name))
315		return PTR_ERR(cipher_name);
316
317	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
318	if (!inst)
319		return -ENOMEM;
 
320
321	spawn = skcipher_instance_ctx(inst);
 
 
322
323	err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
324				   cipher_name, 0, mask);
325	if (err == -ENOENT) {
326		err = -ENAMETOOLONG;
327		if (snprintf(ecb_name, CRYPTO_MAX_ALG_NAME, "ecb(%s)",
328			     cipher_name) >= CRYPTO_MAX_ALG_NAME)
329			goto err_free_inst;
330
331		err = crypto_grab_skcipher(spawn,
332					   skcipher_crypto_instance(inst),
333					   ecb_name, 0, mask);
334	}
335
336	if (err)
337		goto err_free_inst;
 
338
339	alg = crypto_spawn_skcipher_alg_common(spawn);
 
 
 
 
 
 
340
341	err = -EINVAL;
342	if (alg->base.cra_blocksize != LRW_BLOCK_SIZE)
343		goto err_free_inst;
344
345	if (alg->ivsize)
346		goto err_free_inst;
347
348	err = crypto_inst_setname(skcipher_crypto_instance(inst), "lrw",
349				  &alg->base);
350	if (err)
351		goto err_free_inst;
352
353	err = -EINVAL;
354	cipher_name = alg->base.cra_name;
 
 
355
356	/* Alas we screwed up the naming so we have to mangle the
357	 * cipher name.
358	 */
359	if (!strncmp(cipher_name, "ecb(", 4)) {
360		int len;
361
362		len = strscpy(ecb_name, cipher_name + 4, sizeof(ecb_name));
363		if (len < 2)
364			goto err_free_inst;
365
366		if (ecb_name[len - 1] != ')')
367			goto err_free_inst;
368
369		ecb_name[len - 1] = 0;
370
371		if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
372			     "lrw(%s)", ecb_name) >= CRYPTO_MAX_ALG_NAME) {
373			err = -ENAMETOOLONG;
374			goto err_free_inst;
375		}
376	} else
377		goto err_free_inst;
378
379	inst->alg.base.cra_priority = alg->base.cra_priority;
380	inst->alg.base.cra_blocksize = LRW_BLOCK_SIZE;
381	inst->alg.base.cra_alignmask = alg->base.cra_alignmask |
382				       (__alignof__(be128) - 1);
383
384	inst->alg.ivsize = LRW_BLOCK_SIZE;
385	inst->alg.min_keysize = alg->min_keysize + LRW_BLOCK_SIZE;
386	inst->alg.max_keysize = alg->max_keysize + LRW_BLOCK_SIZE;
387
388	inst->alg.base.cra_ctxsize = sizeof(struct lrw_tfm_ctx);
389
390	inst->alg.init = lrw_init_tfm;
391	inst->alg.exit = lrw_exit_tfm;
392
393	inst->alg.setkey = lrw_setkey;
394	inst->alg.encrypt = lrw_encrypt;
395	inst->alg.decrypt = lrw_decrypt;
396
397	inst->free = lrw_free_instance;
398
399	err = skcipher_register_instance(tmpl, inst);
400	if (err) {
401err_free_inst:
402		lrw_free_instance(inst);
403	}
404	return err;
405}
406
407static struct crypto_template lrw_tmpl = {
408	.name = "lrw",
409	.create = lrw_create,
 
410	.module = THIS_MODULE,
411};
412
413static int __init lrw_module_init(void)
414{
415	return crypto_register_template(&lrw_tmpl);
416}
417
418static void __exit lrw_module_exit(void)
419{
420	crypto_unregister_template(&lrw_tmpl);
421}
422
423subsys_initcall(lrw_module_init);
424module_exit(lrw_module_exit);
425
426MODULE_LICENSE("GPL");
427MODULE_DESCRIPTION("LRW block cipher mode");
428MODULE_ALIAS_CRYPTO("lrw");
429MODULE_SOFTDEP("pre: ecb");