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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CTR: Counter mode
4 *
5 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/ctr.h>
10#include <crypto/internal/cipher.h>
11#include <crypto/internal/skcipher.h>
12#include <linux/err.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17
18struct crypto_rfc3686_ctx {
19 struct crypto_skcipher *child;
20 u8 nonce[CTR_RFC3686_NONCE_SIZE];
21};
22
23struct crypto_rfc3686_req_ctx {
24 u8 iv[CTR_RFC3686_BLOCK_SIZE];
25 struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
26};
27
28static void crypto_ctr_crypt_final(struct skcipher_walk *walk,
29 struct crypto_cipher *tfm)
30{
31 unsigned int bsize = crypto_cipher_blocksize(tfm);
32 unsigned long alignmask = crypto_cipher_alignmask(tfm);
33 u8 *ctrblk = walk->iv;
34 u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
35 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
36 u8 *src = walk->src.virt.addr;
37 u8 *dst = walk->dst.virt.addr;
38 unsigned int nbytes = walk->nbytes;
39
40 crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
41 crypto_xor_cpy(dst, keystream, src, nbytes);
42
43 crypto_inc(ctrblk, bsize);
44}
45
46static int crypto_ctr_crypt_segment(struct skcipher_walk *walk,
47 struct crypto_cipher *tfm)
48{
49 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
50 crypto_cipher_alg(tfm)->cia_encrypt;
51 unsigned int bsize = crypto_cipher_blocksize(tfm);
52 u8 *ctrblk = walk->iv;
53 u8 *src = walk->src.virt.addr;
54 u8 *dst = walk->dst.virt.addr;
55 unsigned int nbytes = walk->nbytes;
56
57 do {
58 /* create keystream */
59 fn(crypto_cipher_tfm(tfm), dst, ctrblk);
60 crypto_xor(dst, src, bsize);
61
62 /* increment counter in counterblock */
63 crypto_inc(ctrblk, bsize);
64
65 src += bsize;
66 dst += bsize;
67 } while ((nbytes -= bsize) >= bsize);
68
69 return nbytes;
70}
71
72static int crypto_ctr_crypt_inplace(struct skcipher_walk *walk,
73 struct crypto_cipher *tfm)
74{
75 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
76 crypto_cipher_alg(tfm)->cia_encrypt;
77 unsigned int bsize = crypto_cipher_blocksize(tfm);
78 unsigned long alignmask = crypto_cipher_alignmask(tfm);
79 unsigned int nbytes = walk->nbytes;
80 u8 *ctrblk = walk->iv;
81 u8 *src = walk->src.virt.addr;
82 u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
83 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
84
85 do {
86 /* create keystream */
87 fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
88 crypto_xor(src, keystream, bsize);
89
90 /* increment counter in counterblock */
91 crypto_inc(ctrblk, bsize);
92
93 src += bsize;
94 } while ((nbytes -= bsize) >= bsize);
95
96 return nbytes;
97}
98
99static int crypto_ctr_crypt(struct skcipher_request *req)
100{
101 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
102 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
103 const unsigned int bsize = crypto_cipher_blocksize(cipher);
104 struct skcipher_walk walk;
105 unsigned int nbytes;
106 int err;
107
108 err = skcipher_walk_virt(&walk, req, false);
109
110 while (walk.nbytes >= bsize) {
111 if (walk.src.virt.addr == walk.dst.virt.addr)
112 nbytes = crypto_ctr_crypt_inplace(&walk, cipher);
113 else
114 nbytes = crypto_ctr_crypt_segment(&walk, cipher);
115
116 err = skcipher_walk_done(&walk, nbytes);
117 }
118
119 if (walk.nbytes) {
120 crypto_ctr_crypt_final(&walk, cipher);
121 err = skcipher_walk_done(&walk, 0);
122 }
123
124 return err;
125}
126
127static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb)
128{
129 struct skcipher_instance *inst;
130 struct crypto_alg *alg;
131 int err;
132
133 inst = skcipher_alloc_instance_simple(tmpl, tb);
134 if (IS_ERR(inst))
135 return PTR_ERR(inst);
136
137 alg = skcipher_ialg_simple(inst);
138
139 /* Block size must be >= 4 bytes. */
140 err = -EINVAL;
141 if (alg->cra_blocksize < 4)
142 goto out_free_inst;
143
144 /* If this is false we'd fail the alignment of crypto_inc. */
145 if (alg->cra_blocksize % 4)
146 goto out_free_inst;
147
148 /* CTR mode is a stream cipher. */
149 inst->alg.base.cra_blocksize = 1;
150
151 /*
152 * To simplify the implementation, configure the skcipher walk to only
153 * give a partial block at the very end, never earlier.
154 */
155 inst->alg.chunksize = alg->cra_blocksize;
156
157 inst->alg.encrypt = crypto_ctr_crypt;
158 inst->alg.decrypt = crypto_ctr_crypt;
159
160 err = skcipher_register_instance(tmpl, inst);
161 if (err) {
162out_free_inst:
163 inst->free(inst);
164 }
165
166 return err;
167}
168
169static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
170 const u8 *key, unsigned int keylen)
171{
172 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
173 struct crypto_skcipher *child = ctx->child;
174
175 /* the nonce is stored in bytes at end of key */
176 if (keylen < CTR_RFC3686_NONCE_SIZE)
177 return -EINVAL;
178
179 memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
180 CTR_RFC3686_NONCE_SIZE);
181
182 keylen -= CTR_RFC3686_NONCE_SIZE;
183
184 crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
185 crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
186 CRYPTO_TFM_REQ_MASK);
187 return crypto_skcipher_setkey(child, key, keylen);
188}
189
190static int crypto_rfc3686_crypt(struct skcipher_request *req)
191{
192 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
193 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
194 struct crypto_skcipher *child = ctx->child;
195 unsigned long align = crypto_skcipher_alignmask(tfm);
196 struct crypto_rfc3686_req_ctx *rctx =
197 (void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
198 struct skcipher_request *subreq = &rctx->subreq;
199 u8 *iv = rctx->iv;
200
201 /* set up counter block */
202 memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
203 memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
204
205 /* initialize counter portion of counter block */
206 *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
207 cpu_to_be32(1);
208
209 skcipher_request_set_tfm(subreq, child);
210 skcipher_request_set_callback(subreq, req->base.flags,
211 req->base.complete, req->base.data);
212 skcipher_request_set_crypt(subreq, req->src, req->dst,
213 req->cryptlen, iv);
214
215 return crypto_skcipher_encrypt(subreq);
216}
217
218static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
219{
220 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
221 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
222 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
223 struct crypto_skcipher *cipher;
224 unsigned long align;
225 unsigned int reqsize;
226
227 cipher = crypto_spawn_skcipher(spawn);
228 if (IS_ERR(cipher))
229 return PTR_ERR(cipher);
230
231 ctx->child = cipher;
232
233 align = crypto_skcipher_alignmask(tfm);
234 align &= ~(crypto_tfm_ctx_alignment() - 1);
235 reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
236 crypto_skcipher_reqsize(cipher);
237 crypto_skcipher_set_reqsize(tfm, reqsize);
238
239 return 0;
240}
241
242static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
243{
244 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
245
246 crypto_free_skcipher(ctx->child);
247}
248
249static void crypto_rfc3686_free(struct skcipher_instance *inst)
250{
251 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
252
253 crypto_drop_skcipher(spawn);
254 kfree(inst);
255}
256
257static int crypto_rfc3686_create(struct crypto_template *tmpl,
258 struct rtattr **tb)
259{
260 struct skcipher_instance *inst;
261 struct skcipher_alg *alg;
262 struct crypto_skcipher_spawn *spawn;
263 u32 mask;
264 int err;
265
266 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SKCIPHER, &mask);
267 if (err)
268 return err;
269
270 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
271 if (!inst)
272 return -ENOMEM;
273
274 spawn = skcipher_instance_ctx(inst);
275
276 err = crypto_grab_skcipher(spawn, skcipher_crypto_instance(inst),
277 crypto_attr_alg_name(tb[1]), 0, mask);
278 if (err)
279 goto err_free_inst;
280
281 alg = crypto_spawn_skcipher_alg(spawn);
282
283 /* We only support 16-byte blocks. */
284 err = -EINVAL;
285 if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
286 goto err_free_inst;
287
288 /* Not a stream cipher? */
289 if (alg->base.cra_blocksize != 1)
290 goto err_free_inst;
291
292 err = -ENAMETOOLONG;
293 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
294 "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
295 goto err_free_inst;
296 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
297 "rfc3686(%s)", alg->base.cra_driver_name) >=
298 CRYPTO_MAX_ALG_NAME)
299 goto err_free_inst;
300
301 inst->alg.base.cra_priority = alg->base.cra_priority;
302 inst->alg.base.cra_blocksize = 1;
303 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
304
305 inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
306 inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
307 inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
308 CTR_RFC3686_NONCE_SIZE;
309 inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
310 CTR_RFC3686_NONCE_SIZE;
311
312 inst->alg.setkey = crypto_rfc3686_setkey;
313 inst->alg.encrypt = crypto_rfc3686_crypt;
314 inst->alg.decrypt = crypto_rfc3686_crypt;
315
316 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
317
318 inst->alg.init = crypto_rfc3686_init_tfm;
319 inst->alg.exit = crypto_rfc3686_exit_tfm;
320
321 inst->free = crypto_rfc3686_free;
322
323 err = skcipher_register_instance(tmpl, inst);
324 if (err) {
325err_free_inst:
326 crypto_rfc3686_free(inst);
327 }
328 return err;
329}
330
331static struct crypto_template crypto_ctr_tmpls[] = {
332 {
333 .name = "ctr",
334 .create = crypto_ctr_create,
335 .module = THIS_MODULE,
336 }, {
337 .name = "rfc3686",
338 .create = crypto_rfc3686_create,
339 .module = THIS_MODULE,
340 },
341};
342
343static int __init crypto_ctr_module_init(void)
344{
345 return crypto_register_templates(crypto_ctr_tmpls,
346 ARRAY_SIZE(crypto_ctr_tmpls));
347}
348
349static void __exit crypto_ctr_module_exit(void)
350{
351 crypto_unregister_templates(crypto_ctr_tmpls,
352 ARRAY_SIZE(crypto_ctr_tmpls));
353}
354
355subsys_initcall(crypto_ctr_module_init);
356module_exit(crypto_ctr_module_exit);
357
358MODULE_LICENSE("GPL");
359MODULE_DESCRIPTION("CTR block cipher mode of operation");
360MODULE_ALIAS_CRYPTO("rfc3686");
361MODULE_ALIAS_CRYPTO("ctr");
362MODULE_IMPORT_NS(CRYPTO_INTERNAL);
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * CTR: Counter mode
4 *
5 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
6 */
7
8#include <crypto/algapi.h>
9#include <crypto/ctr.h>
10#include <crypto/internal/skcipher.h>
11#include <linux/err.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16
17struct crypto_rfc3686_ctx {
18 struct crypto_skcipher *child;
19 u8 nonce[CTR_RFC3686_NONCE_SIZE];
20};
21
22struct crypto_rfc3686_req_ctx {
23 u8 iv[CTR_RFC3686_BLOCK_SIZE];
24 struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
25};
26
27static void crypto_ctr_crypt_final(struct skcipher_walk *walk,
28 struct crypto_cipher *tfm)
29{
30 unsigned int bsize = crypto_cipher_blocksize(tfm);
31 unsigned long alignmask = crypto_cipher_alignmask(tfm);
32 u8 *ctrblk = walk->iv;
33 u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
34 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
35 u8 *src = walk->src.virt.addr;
36 u8 *dst = walk->dst.virt.addr;
37 unsigned int nbytes = walk->nbytes;
38
39 crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
40 crypto_xor_cpy(dst, keystream, src, nbytes);
41
42 crypto_inc(ctrblk, bsize);
43}
44
45static int crypto_ctr_crypt_segment(struct skcipher_walk *walk,
46 struct crypto_cipher *tfm)
47{
48 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
49 crypto_cipher_alg(tfm)->cia_encrypt;
50 unsigned int bsize = crypto_cipher_blocksize(tfm);
51 u8 *ctrblk = walk->iv;
52 u8 *src = walk->src.virt.addr;
53 u8 *dst = walk->dst.virt.addr;
54 unsigned int nbytes = walk->nbytes;
55
56 do {
57 /* create keystream */
58 fn(crypto_cipher_tfm(tfm), dst, ctrblk);
59 crypto_xor(dst, src, bsize);
60
61 /* increment counter in counterblock */
62 crypto_inc(ctrblk, bsize);
63
64 src += bsize;
65 dst += bsize;
66 } while ((nbytes -= bsize) >= bsize);
67
68 return nbytes;
69}
70
71static int crypto_ctr_crypt_inplace(struct skcipher_walk *walk,
72 struct crypto_cipher *tfm)
73{
74 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
75 crypto_cipher_alg(tfm)->cia_encrypt;
76 unsigned int bsize = crypto_cipher_blocksize(tfm);
77 unsigned long alignmask = crypto_cipher_alignmask(tfm);
78 unsigned int nbytes = walk->nbytes;
79 u8 *ctrblk = walk->iv;
80 u8 *src = walk->src.virt.addr;
81 u8 tmp[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];
82 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
83
84 do {
85 /* create keystream */
86 fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
87 crypto_xor(src, keystream, bsize);
88
89 /* increment counter in counterblock */
90 crypto_inc(ctrblk, bsize);
91
92 src += bsize;
93 } while ((nbytes -= bsize) >= bsize);
94
95 return nbytes;
96}
97
98static int crypto_ctr_crypt(struct skcipher_request *req)
99{
100 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
101 struct crypto_cipher *cipher = skcipher_cipher_simple(tfm);
102 const unsigned int bsize = crypto_cipher_blocksize(cipher);
103 struct skcipher_walk walk;
104 unsigned int nbytes;
105 int err;
106
107 err = skcipher_walk_virt(&walk, req, false);
108
109 while (walk.nbytes >= bsize) {
110 if (walk.src.virt.addr == walk.dst.virt.addr)
111 nbytes = crypto_ctr_crypt_inplace(&walk, cipher);
112 else
113 nbytes = crypto_ctr_crypt_segment(&walk, cipher);
114
115 err = skcipher_walk_done(&walk, nbytes);
116 }
117
118 if (walk.nbytes) {
119 crypto_ctr_crypt_final(&walk, cipher);
120 err = skcipher_walk_done(&walk, 0);
121 }
122
123 return err;
124}
125
126static int crypto_ctr_create(struct crypto_template *tmpl, struct rtattr **tb)
127{
128 struct skcipher_instance *inst;
129 struct crypto_alg *alg;
130 int err;
131
132 inst = skcipher_alloc_instance_simple(tmpl, tb, &alg);
133 if (IS_ERR(inst))
134 return PTR_ERR(inst);
135
136 /* Block size must be >= 4 bytes. */
137 err = -EINVAL;
138 if (alg->cra_blocksize < 4)
139 goto out_free_inst;
140
141 /* If this is false we'd fail the alignment of crypto_inc. */
142 if (alg->cra_blocksize % 4)
143 goto out_free_inst;
144
145 /* CTR mode is a stream cipher. */
146 inst->alg.base.cra_blocksize = 1;
147
148 /*
149 * To simplify the implementation, configure the skcipher walk to only
150 * give a partial block at the very end, never earlier.
151 */
152 inst->alg.chunksize = alg->cra_blocksize;
153
154 inst->alg.encrypt = crypto_ctr_crypt;
155 inst->alg.decrypt = crypto_ctr_crypt;
156
157 err = skcipher_register_instance(tmpl, inst);
158 if (err)
159 goto out_free_inst;
160 goto out_put_alg;
161
162out_free_inst:
163 inst->free(inst);
164out_put_alg:
165 crypto_mod_put(alg);
166 return err;
167}
168
169static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
170 const u8 *key, unsigned int keylen)
171{
172 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
173 struct crypto_skcipher *child = ctx->child;
174 int err;
175
176 /* the nonce is stored in bytes at end of key */
177 if (keylen < CTR_RFC3686_NONCE_SIZE)
178 return -EINVAL;
179
180 memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
181 CTR_RFC3686_NONCE_SIZE);
182
183 keylen -= CTR_RFC3686_NONCE_SIZE;
184
185 crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
186 crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
187 CRYPTO_TFM_REQ_MASK);
188 err = crypto_skcipher_setkey(child, key, keylen);
189 crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
190 CRYPTO_TFM_RES_MASK);
191
192 return err;
193}
194
195static int crypto_rfc3686_crypt(struct skcipher_request *req)
196{
197 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
198 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
199 struct crypto_skcipher *child = ctx->child;
200 unsigned long align = crypto_skcipher_alignmask(tfm);
201 struct crypto_rfc3686_req_ctx *rctx =
202 (void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
203 struct skcipher_request *subreq = &rctx->subreq;
204 u8 *iv = rctx->iv;
205
206 /* set up counter block */
207 memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
208 memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
209
210 /* initialize counter portion of counter block */
211 *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
212 cpu_to_be32(1);
213
214 skcipher_request_set_tfm(subreq, child);
215 skcipher_request_set_callback(subreq, req->base.flags,
216 req->base.complete, req->base.data);
217 skcipher_request_set_crypt(subreq, req->src, req->dst,
218 req->cryptlen, iv);
219
220 return crypto_skcipher_encrypt(subreq);
221}
222
223static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
224{
225 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
226 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
227 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
228 struct crypto_skcipher *cipher;
229 unsigned long align;
230 unsigned int reqsize;
231
232 cipher = crypto_spawn_skcipher(spawn);
233 if (IS_ERR(cipher))
234 return PTR_ERR(cipher);
235
236 ctx->child = cipher;
237
238 align = crypto_skcipher_alignmask(tfm);
239 align &= ~(crypto_tfm_ctx_alignment() - 1);
240 reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
241 crypto_skcipher_reqsize(cipher);
242 crypto_skcipher_set_reqsize(tfm, reqsize);
243
244 return 0;
245}
246
247static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
248{
249 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
250
251 crypto_free_skcipher(ctx->child);
252}
253
254static void crypto_rfc3686_free(struct skcipher_instance *inst)
255{
256 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
257
258 crypto_drop_skcipher(spawn);
259 kfree(inst);
260}
261
262static int crypto_rfc3686_create(struct crypto_template *tmpl,
263 struct rtattr **tb)
264{
265 struct crypto_attr_type *algt;
266 struct skcipher_instance *inst;
267 struct skcipher_alg *alg;
268 struct crypto_skcipher_spawn *spawn;
269 const char *cipher_name;
270 u32 mask;
271
272 int err;
273
274 algt = crypto_get_attr_type(tb);
275 if (IS_ERR(algt))
276 return PTR_ERR(algt);
277
278 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
279 return -EINVAL;
280
281 cipher_name = crypto_attr_alg_name(tb[1]);
282 if (IS_ERR(cipher_name))
283 return PTR_ERR(cipher_name);
284
285 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
286 if (!inst)
287 return -ENOMEM;
288
289 mask = crypto_requires_sync(algt->type, algt->mask) |
290 crypto_requires_off(algt->type, algt->mask,
291 CRYPTO_ALG_NEED_FALLBACK);
292
293 spawn = skcipher_instance_ctx(inst);
294
295 crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
296 err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
297 if (err)
298 goto err_free_inst;
299
300 alg = crypto_spawn_skcipher_alg(spawn);
301
302 /* We only support 16-byte blocks. */
303 err = -EINVAL;
304 if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
305 goto err_drop_spawn;
306
307 /* Not a stream cipher? */
308 if (alg->base.cra_blocksize != 1)
309 goto err_drop_spawn;
310
311 err = -ENAMETOOLONG;
312 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
313 "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
314 goto err_drop_spawn;
315 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
316 "rfc3686(%s)", alg->base.cra_driver_name) >=
317 CRYPTO_MAX_ALG_NAME)
318 goto err_drop_spawn;
319
320 inst->alg.base.cra_priority = alg->base.cra_priority;
321 inst->alg.base.cra_blocksize = 1;
322 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
323
324 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
325
326 inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
327 inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
328 inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
329 CTR_RFC3686_NONCE_SIZE;
330 inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
331 CTR_RFC3686_NONCE_SIZE;
332
333 inst->alg.setkey = crypto_rfc3686_setkey;
334 inst->alg.encrypt = crypto_rfc3686_crypt;
335 inst->alg.decrypt = crypto_rfc3686_crypt;
336
337 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
338
339 inst->alg.init = crypto_rfc3686_init_tfm;
340 inst->alg.exit = crypto_rfc3686_exit_tfm;
341
342 inst->free = crypto_rfc3686_free;
343
344 err = skcipher_register_instance(tmpl, inst);
345 if (err)
346 goto err_drop_spawn;
347
348out:
349 return err;
350
351err_drop_spawn:
352 crypto_drop_skcipher(spawn);
353err_free_inst:
354 kfree(inst);
355 goto out;
356}
357
358static struct crypto_template crypto_ctr_tmpls[] = {
359 {
360 .name = "ctr",
361 .create = crypto_ctr_create,
362 .module = THIS_MODULE,
363 }, {
364 .name = "rfc3686",
365 .create = crypto_rfc3686_create,
366 .module = THIS_MODULE,
367 },
368};
369
370static int __init crypto_ctr_module_init(void)
371{
372 return crypto_register_templates(crypto_ctr_tmpls,
373 ARRAY_SIZE(crypto_ctr_tmpls));
374}
375
376static void __exit crypto_ctr_module_exit(void)
377{
378 crypto_unregister_templates(crypto_ctr_tmpls,
379 ARRAY_SIZE(crypto_ctr_tmpls));
380}
381
382subsys_initcall(crypto_ctr_module_init);
383module_exit(crypto_ctr_module_exit);
384
385MODULE_LICENSE("GPL");
386MODULE_DESCRIPTION("CTR block cipher mode of operation");
387MODULE_ALIAS_CRYPTO("rfc3686");
388MODULE_ALIAS_CRYPTO("ctr");