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Joy Latten23e353c2007-10-23 08:50:32 +08001/*
2 * CTR: Counter mode
3 *
4 * (C) Copyright IBM Corp. 2007 - Joy Latten <latten@us.ibm.com>
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms of the GNU General Public License as published by the Free
8 * Software Foundation; either version 2 of the License, or (at your option)
9 * any later version.
10 *
11 */
12
13#include <crypto/algapi.h>
Herbert Xu5311f242007-12-17 21:34:32 +080014#include <crypto/ctr.h>
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +020015#include <crypto/internal/skcipher.h>
Joy Latten23e353c2007-10-23 08:50:32 +080016#include <linux/err.h>
17#include <linux/init.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/random.h>
21#include <linux/scatterlist.h>
22#include <linux/slab.h>
23
Joy Latten23e353c2007-10-23 08:50:32 +080024struct crypto_ctr_ctx {
25 struct crypto_cipher *child;
Herbert Xu5311f242007-12-17 21:34:32 +080026};
27
28struct crypto_rfc3686_ctx {
Herbert Xub2b39c22016-07-12 13:17:37 +080029 struct crypto_skcipher *child;
Herbert Xu5311f242007-12-17 21:34:32 +080030 u8 nonce[CTR_RFC3686_NONCE_SIZE];
Joy Latten23e353c2007-10-23 08:50:32 +080031};
32
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +020033struct crypto_rfc3686_req_ctx {
34 u8 iv[CTR_RFC3686_BLOCK_SIZE];
Herbert Xub2b39c22016-07-12 13:17:37 +080035 struct skcipher_request subreq CRYPTO_MINALIGN_ATTR;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +020036};
37
Joy Latten23e353c2007-10-23 08:50:32 +080038static int crypto_ctr_setkey(struct crypto_tfm *parent, const u8 *key,
39 unsigned int keylen)
40{
41 struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(parent);
42 struct crypto_cipher *child = ctx->child;
Herbert Xu5311f242007-12-17 21:34:32 +080043 int err;
Joy Latten23e353c2007-10-23 08:50:32 +080044
45 crypto_cipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
46 crypto_cipher_set_flags(child, crypto_tfm_get_flags(parent) &
47 CRYPTO_TFM_REQ_MASK);
48 err = crypto_cipher_setkey(child, key, keylen);
49 crypto_tfm_set_flags(parent, crypto_cipher_get_flags(child) &
50 CRYPTO_TFM_RES_MASK);
51
52 return err;
53}
54
Herbert Xu0971eb02007-11-30 00:23:53 +110055static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
Herbert Xu5311f242007-12-17 21:34:32 +080056 struct crypto_cipher *tfm)
Herbert Xu0971eb02007-11-30 00:23:53 +110057{
58 unsigned int bsize = crypto_cipher_blocksize(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +080059 unsigned long alignmask = crypto_cipher_alignmask(tfm);
60 u8 *ctrblk = walk->iv;
61 u8 tmp[bsize + alignmask];
62 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
Herbert Xu0971eb02007-11-30 00:23:53 +110063 u8 *src = walk->src.virt.addr;
64 u8 *dst = walk->dst.virt.addr;
65 unsigned int nbytes = walk->nbytes;
66
67 crypto_cipher_encrypt_one(tfm, keystream, ctrblk);
Ard Biesheuvel45fe93d2017-07-24 11:28:04 +010068 crypto_xor_cpy(dst, keystream, src, nbytes);
Herbert Xu5311f242007-12-17 21:34:32 +080069
70 crypto_inc(ctrblk, bsize);
Herbert Xu0971eb02007-11-30 00:23:53 +110071}
72
Joy Latten23e353c2007-10-23 08:50:32 +080073static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
Herbert Xu5311f242007-12-17 21:34:32 +080074 struct crypto_cipher *tfm)
Joy Latten23e353c2007-10-23 08:50:32 +080075{
76 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
77 crypto_cipher_alg(tfm)->cia_encrypt;
78 unsigned int bsize = crypto_cipher_blocksize(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +080079 u8 *ctrblk = walk->iv;
Joy Latten23e353c2007-10-23 08:50:32 +080080 u8 *src = walk->src.virt.addr;
81 u8 *dst = walk->dst.virt.addr;
82 unsigned int nbytes = walk->nbytes;
83
84 do {
85 /* create keystream */
Herbert Xu0971eb02007-11-30 00:23:53 +110086 fn(crypto_cipher_tfm(tfm), dst, ctrblk);
87 crypto_xor(dst, src, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080088
89 /* increment counter in counterblock */
Herbert Xu5311f242007-12-17 21:34:32 +080090 crypto_inc(ctrblk, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080091
Joy Latten23e353c2007-10-23 08:50:32 +080092 src += bsize;
93 dst += bsize;
Herbert Xu0971eb02007-11-30 00:23:53 +110094 } while ((nbytes -= bsize) >= bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080095
Herbert Xu0971eb02007-11-30 00:23:53 +110096 return nbytes;
Joy Latten23e353c2007-10-23 08:50:32 +080097}
98
99static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
Herbert Xu5311f242007-12-17 21:34:32 +0800100 struct crypto_cipher *tfm)
Joy Latten23e353c2007-10-23 08:50:32 +0800101{
102 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
103 crypto_cipher_alg(tfm)->cia_encrypt;
104 unsigned int bsize = crypto_cipher_blocksize(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +0800105 unsigned long alignmask = crypto_cipher_alignmask(tfm);
Joy Latten23e353c2007-10-23 08:50:32 +0800106 unsigned int nbytes = walk->nbytes;
Herbert Xu5311f242007-12-17 21:34:32 +0800107 u8 *ctrblk = walk->iv;
Joy Latten23e353c2007-10-23 08:50:32 +0800108 u8 *src = walk->src.virt.addr;
Herbert Xu5311f242007-12-17 21:34:32 +0800109 u8 tmp[bsize + alignmask];
110 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
Joy Latten23e353c2007-10-23 08:50:32 +0800111
112 do {
113 /* create keystream */
114 fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
Herbert Xu0971eb02007-11-30 00:23:53 +1100115 crypto_xor(src, keystream, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800116
117 /* increment counter in counterblock */
Herbert Xu5311f242007-12-17 21:34:32 +0800118 crypto_inc(ctrblk, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800119
Joy Latten23e353c2007-10-23 08:50:32 +0800120 src += bsize;
Herbert Xu0971eb02007-11-30 00:23:53 +1100121 } while ((nbytes -= bsize) >= bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800122
Herbert Xu0971eb02007-11-30 00:23:53 +1100123 return nbytes;
Joy Latten23e353c2007-10-23 08:50:32 +0800124}
125
126static int crypto_ctr_crypt(struct blkcipher_desc *desc,
127 struct scatterlist *dst, struct scatterlist *src,
128 unsigned int nbytes)
129{
130 struct blkcipher_walk walk;
131 struct crypto_blkcipher *tfm = desc->tfm;
132 struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
133 struct crypto_cipher *child = ctx->child;
134 unsigned int bsize = crypto_cipher_blocksize(child);
Joy Latten23e353c2007-10-23 08:50:32 +0800135 int err;
136
137 blkcipher_walk_init(&walk, dst, src, nbytes);
138 err = blkcipher_walk_virt_block(desc, &walk, bsize);
139
Herbert Xu0971eb02007-11-30 00:23:53 +1100140 while (walk.nbytes >= bsize) {
Joy Latten23e353c2007-10-23 08:50:32 +0800141 if (walk.src.virt.addr == walk.dst.virt.addr)
Herbert Xu5311f242007-12-17 21:34:32 +0800142 nbytes = crypto_ctr_crypt_inplace(&walk, child);
Joy Latten23e353c2007-10-23 08:50:32 +0800143 else
Herbert Xu5311f242007-12-17 21:34:32 +0800144 nbytes = crypto_ctr_crypt_segment(&walk, child);
Joy Latten23e353c2007-10-23 08:50:32 +0800145
146 err = blkcipher_walk_done(desc, &walk, nbytes);
147 }
Herbert Xu0971eb02007-11-30 00:23:53 +1100148
149 if (walk.nbytes) {
Herbert Xu5311f242007-12-17 21:34:32 +0800150 crypto_ctr_crypt_final(&walk, child);
Herbert Xu0971eb02007-11-30 00:23:53 +1100151 err = blkcipher_walk_done(desc, &walk, 0);
152 }
153
Joy Latten23e353c2007-10-23 08:50:32 +0800154 return err;
155}
156
157static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
158{
159 struct crypto_instance *inst = (void *)tfm->__crt_alg;
Herbert Xu5311f242007-12-17 21:34:32 +0800160 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
Joy Latten23e353c2007-10-23 08:50:32 +0800161 struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
162 struct crypto_cipher *cipher;
163
Herbert Xu5311f242007-12-17 21:34:32 +0800164 cipher = crypto_spawn_cipher(spawn);
Joy Latten23e353c2007-10-23 08:50:32 +0800165 if (IS_ERR(cipher))
166 return PTR_ERR(cipher);
167
168 ctx->child = cipher;
169
170 return 0;
171}
172
173static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
174{
175 struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
176
Joy Latten23e353c2007-10-23 08:50:32 +0800177 crypto_free_cipher(ctx->child);
178}
179
180static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
181{
182 struct crypto_instance *inst;
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300183 struct crypto_attr_type *algt;
Joy Latten23e353c2007-10-23 08:50:32 +0800184 struct crypto_alg *alg;
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300185 u32 mask;
Joy Latten23e353c2007-10-23 08:50:32 +0800186 int err;
187
188 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
189 if (err)
190 return ERR_PTR(err);
191
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300192 algt = crypto_get_attr_type(tb);
193 if (IS_ERR(algt))
194 return ERR_CAST(algt);
195
196 mask = CRYPTO_ALG_TYPE_MASK |
197 crypto_requires_off(algt->type, algt->mask,
198 CRYPTO_ALG_NEED_FALLBACK);
199
200 alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER, mask);
Joy Latten23e353c2007-10-23 08:50:32 +0800201 if (IS_ERR(alg))
Julia Lawall8db050782010-05-26 10:36:51 +1000202 return ERR_CAST(alg);
Joy Latten23e353c2007-10-23 08:50:32 +0800203
Herbert Xu5311f242007-12-17 21:34:32 +0800204 /* Block size must be >= 4 bytes. */
Joy Latten23e353c2007-10-23 08:50:32 +0800205 err = -EINVAL;
Herbert Xu5311f242007-12-17 21:34:32 +0800206 if (alg->cra_blocksize < 4)
Joy Latten23e353c2007-10-23 08:50:32 +0800207 goto out_put_alg;
208
Herbert Xu3f8214e2007-11-20 20:32:56 +0800209 /* If this is false we'd fail the alignment of crypto_inc. */
Herbert Xu5311f242007-12-17 21:34:32 +0800210 if (alg->cra_blocksize % 4)
Herbert Xu3f8214e2007-11-20 20:32:56 +0800211 goto out_put_alg;
212
Herbert Xu5311f242007-12-17 21:34:32 +0800213 inst = crypto_alloc_instance("ctr", alg);
214 if (IS_ERR(inst))
215 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800216
Joy Latten23e353c2007-10-23 08:50:32 +0800217 inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
218 inst->alg.cra_priority = alg->cra_priority;
219 inst->alg.cra_blocksize = 1;
Ard Biesheuveldb91af02017-02-05 10:06:12 +0000220 inst->alg.cra_alignmask = alg->cra_alignmask;
Joy Latten23e353c2007-10-23 08:50:32 +0800221 inst->alg.cra_type = &crypto_blkcipher_type;
222
Herbert Xu5311f242007-12-17 21:34:32 +0800223 inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
224 inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
225 inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
Joy Latten23e353c2007-10-23 08:50:32 +0800226
227 inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
228
229 inst->alg.cra_init = crypto_ctr_init_tfm;
230 inst->alg.cra_exit = crypto_ctr_exit_tfm;
231
232 inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
233 inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
234 inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
235
Herbert Xuaef27132009-08-13 23:10:39 +1000236 inst->alg.cra_blkcipher.geniv = "chainiv";
237
Herbert Xu5311f242007-12-17 21:34:32 +0800238out:
239 crypto_mod_put(alg);
240 return inst;
Joy Latten23e353c2007-10-23 08:50:32 +0800241
242out_put_alg:
Herbert Xu5311f242007-12-17 21:34:32 +0800243 inst = ERR_PTR(err);
244 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800245}
246
247static void crypto_ctr_free(struct crypto_instance *inst)
248{
Herbert Xu5311f242007-12-17 21:34:32 +0800249 crypto_drop_spawn(crypto_instance_ctx(inst));
Joy Latten23e353c2007-10-23 08:50:32 +0800250 kfree(inst);
251}
252
253static struct crypto_template crypto_ctr_tmpl = {
254 .name = "ctr",
255 .alloc = crypto_ctr_alloc,
256 .free = crypto_ctr_free,
257 .module = THIS_MODULE,
258};
259
Herbert Xub2b39c22016-07-12 13:17:37 +0800260static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200261 const u8 *key, unsigned int keylen)
Herbert Xu5311f242007-12-17 21:34:32 +0800262{
Herbert Xub2b39c22016-07-12 13:17:37 +0800263 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
264 struct crypto_skcipher *child = ctx->child;
Herbert Xu5311f242007-12-17 21:34:32 +0800265 int err;
266
267 /* the nonce is stored in bytes at end of key */
268 if (keylen < CTR_RFC3686_NONCE_SIZE)
269 return -EINVAL;
270
271 memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
272 CTR_RFC3686_NONCE_SIZE);
273
274 keylen -= CTR_RFC3686_NONCE_SIZE;
275
Herbert Xub2b39c22016-07-12 13:17:37 +0800276 crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
277 crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
278 CRYPTO_TFM_REQ_MASK);
279 err = crypto_skcipher_setkey(child, key, keylen);
280 crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
281 CRYPTO_TFM_RES_MASK);
Herbert Xu5311f242007-12-17 21:34:32 +0800282
283 return err;
284}
285
Herbert Xub2b39c22016-07-12 13:17:37 +0800286static int crypto_rfc3686_crypt(struct skcipher_request *req)
Herbert Xu5311f242007-12-17 21:34:32 +0800287{
Herbert Xub2b39c22016-07-12 13:17:37 +0800288 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
289 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
290 struct crypto_skcipher *child = ctx->child;
291 unsigned long align = crypto_skcipher_alignmask(tfm);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200292 struct crypto_rfc3686_req_ctx *rctx =
Herbert Xub2b39c22016-07-12 13:17:37 +0800293 (void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
294 struct skcipher_request *subreq = &rctx->subreq;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200295 u8 *iv = rctx->iv;
Herbert Xu5311f242007-12-17 21:34:32 +0800296
297 /* set up counter block */
298 memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
Herbert Xub2b39c22016-07-12 13:17:37 +0800299 memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
Herbert Xu5311f242007-12-17 21:34:32 +0800300
301 /* initialize counter portion of counter block */
302 *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
303 cpu_to_be32(1);
304
Herbert Xub2b39c22016-07-12 13:17:37 +0800305 skcipher_request_set_tfm(subreq, child);
306 skcipher_request_set_callback(subreq, req->base.flags,
307 req->base.complete, req->base.data);
308 skcipher_request_set_crypt(subreq, req->src, req->dst,
309 req->cryptlen, iv);
Herbert Xu5311f242007-12-17 21:34:32 +0800310
Herbert Xub2b39c22016-07-12 13:17:37 +0800311 return crypto_skcipher_encrypt(subreq);
Herbert Xu5311f242007-12-17 21:34:32 +0800312}
313
Herbert Xub2b39c22016-07-12 13:17:37 +0800314static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
Herbert Xu5311f242007-12-17 21:34:32 +0800315{
Herbert Xub2b39c22016-07-12 13:17:37 +0800316 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
317 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
318 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
319 struct crypto_skcipher *cipher;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200320 unsigned long align;
Herbert Xub2b39c22016-07-12 13:17:37 +0800321 unsigned int reqsize;
Herbert Xu5311f242007-12-17 21:34:32 +0800322
Eric Biggers60425a82016-10-28 09:52:19 -0700323 cipher = crypto_spawn_skcipher(spawn);
Herbert Xu5311f242007-12-17 21:34:32 +0800324 if (IS_ERR(cipher))
325 return PTR_ERR(cipher);
326
327 ctx->child = cipher;
328
Herbert Xub2b39c22016-07-12 13:17:37 +0800329 align = crypto_skcipher_alignmask(tfm);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200330 align &= ~(crypto_tfm_ctx_alignment() - 1);
Herbert Xub2b39c22016-07-12 13:17:37 +0800331 reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
332 crypto_skcipher_reqsize(cipher);
333 crypto_skcipher_set_reqsize(tfm, reqsize);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200334
Herbert Xu5311f242007-12-17 21:34:32 +0800335 return 0;
336}
337
Herbert Xub2b39c22016-07-12 13:17:37 +0800338static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
Herbert Xu5311f242007-12-17 21:34:32 +0800339{
Herbert Xub2b39c22016-07-12 13:17:37 +0800340 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +0800341
Herbert Xub2b39c22016-07-12 13:17:37 +0800342 crypto_free_skcipher(ctx->child);
Herbert Xu5311f242007-12-17 21:34:32 +0800343}
344
Herbert Xub2b39c22016-07-12 13:17:37 +0800345static void crypto_rfc3686_free(struct skcipher_instance *inst)
346{
347 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
348
349 crypto_drop_skcipher(spawn);
350 kfree(inst);
351}
352
353static int crypto_rfc3686_create(struct crypto_template *tmpl,
354 struct rtattr **tb)
Herbert Xu5311f242007-12-17 21:34:32 +0800355{
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200356 struct crypto_attr_type *algt;
Herbert Xub2b39c22016-07-12 13:17:37 +0800357 struct skcipher_instance *inst;
358 struct skcipher_alg *alg;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200359 struct crypto_skcipher_spawn *spawn;
360 const char *cipher_name;
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300361 u32 mask;
362
Herbert Xu5311f242007-12-17 21:34:32 +0800363 int err;
364
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200365 algt = crypto_get_attr_type(tb);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200366 if (IS_ERR(algt))
Herbert Xub2b39c22016-07-12 13:17:37 +0800367 return PTR_ERR(algt);
Herbert Xu5311f242007-12-17 21:34:32 +0800368
Herbert Xub2b39c22016-07-12 13:17:37 +0800369 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
370 return -EINVAL;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200371
372 cipher_name = crypto_attr_alg_name(tb[1]);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200373 if (IS_ERR(cipher_name))
Herbert Xub2b39c22016-07-12 13:17:37 +0800374 return PTR_ERR(cipher_name);
Herbert Xu5311f242007-12-17 21:34:32 +0800375
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200376 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
377 if (!inst)
Herbert Xub2b39c22016-07-12 13:17:37 +0800378 return -ENOMEM;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200379
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300380 mask = crypto_requires_sync(algt->type, algt->mask) |
381 crypto_requires_off(algt->type, algt->mask,
382 CRYPTO_ALG_NEED_FALLBACK);
383
Herbert Xub2b39c22016-07-12 13:17:37 +0800384 spawn = skcipher_instance_ctx(inst);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200385
Herbert Xub2b39c22016-07-12 13:17:37 +0800386 crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
Marcelo Cerrid2c2a852017-02-27 09:38:26 -0300387 err = crypto_grab_skcipher(spawn, cipher_name, 0, mask);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200388 if (err)
389 goto err_free_inst;
390
Herbert Xub2b39c22016-07-12 13:17:37 +0800391 alg = crypto_spawn_skcipher_alg(spawn);
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200392
Herbert Xu5311f242007-12-17 21:34:32 +0800393 /* We only support 16-byte blocks. */
394 err = -EINVAL;
Herbert Xub2b39c22016-07-12 13:17:37 +0800395 if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200396 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800397
398 /* Not a stream cipher? */
Herbert Xub2b39c22016-07-12 13:17:37 +0800399 if (alg->base.cra_blocksize != 1)
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200400 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800401
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200402 err = -ENAMETOOLONG;
Herbert Xub2b39c22016-07-12 13:17:37 +0800403 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
404 "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200405 goto err_drop_spawn;
Herbert Xub2b39c22016-07-12 13:17:37 +0800406 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
407 "rfc3686(%s)", alg->base.cra_driver_name) >=
408 CRYPTO_MAX_ALG_NAME)
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200409 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800410
Herbert Xub2b39c22016-07-12 13:17:37 +0800411 inst->alg.base.cra_priority = alg->base.cra_priority;
412 inst->alg.base.cra_blocksize = 1;
413 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Herbert Xu5311f242007-12-17 21:34:32 +0800414
Herbert Xub2b39c22016-07-12 13:17:37 +0800415 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
Herbert Xu5311f242007-12-17 21:34:32 +0800416
Herbert Xub2b39c22016-07-12 13:17:37 +0800417 inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
418 inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
419 inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
420 CTR_RFC3686_NONCE_SIZE;
421 inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
422 CTR_RFC3686_NONCE_SIZE;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200423
Herbert Xub2b39c22016-07-12 13:17:37 +0800424 inst->alg.setkey = crypto_rfc3686_setkey;
425 inst->alg.encrypt = crypto_rfc3686_crypt;
426 inst->alg.decrypt = crypto_rfc3686_crypt;
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200427
Herbert Xub2b39c22016-07-12 13:17:37 +0800428 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
Herbert Xu0a270322007-11-30 21:38:37 +1100429
Herbert Xub2b39c22016-07-12 13:17:37 +0800430 inst->alg.init = crypto_rfc3686_init_tfm;
431 inst->alg.exit = crypto_rfc3686_exit_tfm;
Herbert Xu5311f242007-12-17 21:34:32 +0800432
Herbert Xub2b39c22016-07-12 13:17:37 +0800433 inst->free = crypto_rfc3686_free;
Herbert Xu5311f242007-12-17 21:34:32 +0800434
Herbert Xub2b39c22016-07-12 13:17:37 +0800435 err = skcipher_register_instance(tmpl, inst);
436 if (err)
437 goto err_drop_spawn;
438
439out:
440 return err;
Herbert Xu5311f242007-12-17 21:34:32 +0800441
Jussi Kivilinna69d3150c2012-12-28 12:04:58 +0200442err_drop_spawn:
443 crypto_drop_skcipher(spawn);
444err_free_inst:
445 kfree(inst);
Herbert Xub2b39c22016-07-12 13:17:37 +0800446 goto out;
Herbert Xu5311f242007-12-17 21:34:32 +0800447}
448
449static struct crypto_template crypto_rfc3686_tmpl = {
450 .name = "rfc3686",
Herbert Xub2b39c22016-07-12 13:17:37 +0800451 .create = crypto_rfc3686_create,
Herbert Xu5311f242007-12-17 21:34:32 +0800452 .module = THIS_MODULE,
453};
454
Joy Latten23e353c2007-10-23 08:50:32 +0800455static int __init crypto_ctr_module_init(void)
456{
Herbert Xu5311f242007-12-17 21:34:32 +0800457 int err;
458
459 err = crypto_register_template(&crypto_ctr_tmpl);
460 if (err)
461 goto out;
462
463 err = crypto_register_template(&crypto_rfc3686_tmpl);
464 if (err)
465 goto out_drop_ctr;
466
467out:
468 return err;
469
470out_drop_ctr:
471 crypto_unregister_template(&crypto_ctr_tmpl);
472 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800473}
474
475static void __exit crypto_ctr_module_exit(void)
476{
Herbert Xu5311f242007-12-17 21:34:32 +0800477 crypto_unregister_template(&crypto_rfc3686_tmpl);
Joy Latten23e353c2007-10-23 08:50:32 +0800478 crypto_unregister_template(&crypto_ctr_tmpl);
479}
480
481module_init(crypto_ctr_module_init);
482module_exit(crypto_ctr_module_exit);
483
484MODULE_LICENSE("GPL");
485MODULE_DESCRIPTION("CTR Counter block mode");
Kees Cook5d26a102014-11-20 17:05:53 -0800486MODULE_ALIAS_CRYPTO("rfc3686");
Kees Cook4943ba12014-11-24 16:32:38 -0800487MODULE_ALIAS_CRYPTO("ctr");