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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 Kivilinna69d31502012-12-28 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 Kivilinna69d31502012-12-28 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 Kivilinna69d31502012-12-28 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);
68 crypto_xor(keystream, src, nbytes);
69 memcpy(dst, keystream, nbytes);
Herbert Xu5311f242007-12-17 21:34:32 +080070
71 crypto_inc(ctrblk, bsize);
Herbert Xu0971eb02007-11-30 00:23:53 +110072}
73
Joy Latten23e353c2007-10-23 08:50:32 +080074static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
Herbert Xu5311f242007-12-17 21:34:32 +080075 struct crypto_cipher *tfm)
Joy Latten23e353c2007-10-23 08:50:32 +080076{
77 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
78 crypto_cipher_alg(tfm)->cia_encrypt;
79 unsigned int bsize = crypto_cipher_blocksize(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +080080 u8 *ctrblk = walk->iv;
Joy Latten23e353c2007-10-23 08:50:32 +080081 u8 *src = walk->src.virt.addr;
82 u8 *dst = walk->dst.virt.addr;
83 unsigned int nbytes = walk->nbytes;
84
85 do {
86 /* create keystream */
Herbert Xu0971eb02007-11-30 00:23:53 +110087 fn(crypto_cipher_tfm(tfm), dst, ctrblk);
88 crypto_xor(dst, src, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080089
90 /* increment counter in counterblock */
Herbert Xu5311f242007-12-17 21:34:32 +080091 crypto_inc(ctrblk, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080092
Joy Latten23e353c2007-10-23 08:50:32 +080093 src += bsize;
94 dst += bsize;
Herbert Xu0971eb02007-11-30 00:23:53 +110095 } while ((nbytes -= bsize) >= bsize);
Joy Latten23e353c2007-10-23 08:50:32 +080096
Herbert Xu0971eb02007-11-30 00:23:53 +110097 return nbytes;
Joy Latten23e353c2007-10-23 08:50:32 +080098}
99
100static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
Herbert Xu5311f242007-12-17 21:34:32 +0800101 struct crypto_cipher *tfm)
Joy Latten23e353c2007-10-23 08:50:32 +0800102{
103 void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
104 crypto_cipher_alg(tfm)->cia_encrypt;
105 unsigned int bsize = crypto_cipher_blocksize(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +0800106 unsigned long alignmask = crypto_cipher_alignmask(tfm);
Joy Latten23e353c2007-10-23 08:50:32 +0800107 unsigned int nbytes = walk->nbytes;
Herbert Xu5311f242007-12-17 21:34:32 +0800108 u8 *ctrblk = walk->iv;
Joy Latten23e353c2007-10-23 08:50:32 +0800109 u8 *src = walk->src.virt.addr;
Herbert Xu5311f242007-12-17 21:34:32 +0800110 u8 tmp[bsize + alignmask];
111 u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
Joy Latten23e353c2007-10-23 08:50:32 +0800112
113 do {
114 /* create keystream */
115 fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
Herbert Xu0971eb02007-11-30 00:23:53 +1100116 crypto_xor(src, keystream, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800117
118 /* increment counter in counterblock */
Herbert Xu5311f242007-12-17 21:34:32 +0800119 crypto_inc(ctrblk, bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800120
Joy Latten23e353c2007-10-23 08:50:32 +0800121 src += bsize;
Herbert Xu0971eb02007-11-30 00:23:53 +1100122 } while ((nbytes -= bsize) >= bsize);
Joy Latten23e353c2007-10-23 08:50:32 +0800123
Herbert Xu0971eb02007-11-30 00:23:53 +1100124 return nbytes;
Joy Latten23e353c2007-10-23 08:50:32 +0800125}
126
127static int crypto_ctr_crypt(struct blkcipher_desc *desc,
128 struct scatterlist *dst, struct scatterlist *src,
129 unsigned int nbytes)
130{
131 struct blkcipher_walk walk;
132 struct crypto_blkcipher *tfm = desc->tfm;
133 struct crypto_ctr_ctx *ctx = crypto_blkcipher_ctx(tfm);
134 struct crypto_cipher *child = ctx->child;
135 unsigned int bsize = crypto_cipher_blocksize(child);
Joy Latten23e353c2007-10-23 08:50:32 +0800136 int err;
137
138 blkcipher_walk_init(&walk, dst, src, nbytes);
139 err = blkcipher_walk_virt_block(desc, &walk, bsize);
140
Herbert Xu0971eb02007-11-30 00:23:53 +1100141 while (walk.nbytes >= bsize) {
Joy Latten23e353c2007-10-23 08:50:32 +0800142 if (walk.src.virt.addr == walk.dst.virt.addr)
Herbert Xu5311f242007-12-17 21:34:32 +0800143 nbytes = crypto_ctr_crypt_inplace(&walk, child);
Joy Latten23e353c2007-10-23 08:50:32 +0800144 else
Herbert Xu5311f242007-12-17 21:34:32 +0800145 nbytes = crypto_ctr_crypt_segment(&walk, child);
Joy Latten23e353c2007-10-23 08:50:32 +0800146
147 err = blkcipher_walk_done(desc, &walk, nbytes);
148 }
Herbert Xu0971eb02007-11-30 00:23:53 +1100149
150 if (walk.nbytes) {
Herbert Xu5311f242007-12-17 21:34:32 +0800151 crypto_ctr_crypt_final(&walk, child);
Herbert Xu0971eb02007-11-30 00:23:53 +1100152 err = blkcipher_walk_done(desc, &walk, 0);
153 }
154
Joy Latten23e353c2007-10-23 08:50:32 +0800155 return err;
156}
157
158static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
159{
160 struct crypto_instance *inst = (void *)tfm->__crt_alg;
Herbert Xu5311f242007-12-17 21:34:32 +0800161 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
Joy Latten23e353c2007-10-23 08:50:32 +0800162 struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
163 struct crypto_cipher *cipher;
164
Herbert Xu5311f242007-12-17 21:34:32 +0800165 cipher = crypto_spawn_cipher(spawn);
Joy Latten23e353c2007-10-23 08:50:32 +0800166 if (IS_ERR(cipher))
167 return PTR_ERR(cipher);
168
169 ctx->child = cipher;
170
171 return 0;
172}
173
174static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
175{
176 struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
177
Joy Latten23e353c2007-10-23 08:50:32 +0800178 crypto_free_cipher(ctx->child);
179}
180
181static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
182{
183 struct crypto_instance *inst;
184 struct crypto_alg *alg;
Joy Latten23e353c2007-10-23 08:50:32 +0800185 int err;
186
187 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_BLKCIPHER);
188 if (err)
189 return ERR_PTR(err);
190
191 alg = crypto_attr_alg(tb[1], CRYPTO_ALG_TYPE_CIPHER,
192 CRYPTO_ALG_TYPE_MASK);
193 if (IS_ERR(alg))
Julia Lawall8db05072010-05-26 10:36:51 +1000194 return ERR_CAST(alg);
Joy Latten23e353c2007-10-23 08:50:32 +0800195
Herbert Xu5311f242007-12-17 21:34:32 +0800196 /* Block size must be >= 4 bytes. */
Joy Latten23e353c2007-10-23 08:50:32 +0800197 err = -EINVAL;
Herbert Xu5311f242007-12-17 21:34:32 +0800198 if (alg->cra_blocksize < 4)
Joy Latten23e353c2007-10-23 08:50:32 +0800199 goto out_put_alg;
200
Herbert Xu3f8214e2007-11-20 20:32:56 +0800201 /* If this is false we'd fail the alignment of crypto_inc. */
Herbert Xu5311f242007-12-17 21:34:32 +0800202 if (alg->cra_blocksize % 4)
Herbert Xu3f8214e2007-11-20 20:32:56 +0800203 goto out_put_alg;
204
Herbert Xu5311f242007-12-17 21:34:32 +0800205 inst = crypto_alloc_instance("ctr", alg);
206 if (IS_ERR(inst))
207 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800208
Joy Latten23e353c2007-10-23 08:50:32 +0800209 inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
210 inst->alg.cra_priority = alg->cra_priority;
211 inst->alg.cra_blocksize = 1;
Herbert Xu0971eb02007-11-30 00:23:53 +1100212 inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1);
Joy Latten23e353c2007-10-23 08:50:32 +0800213 inst->alg.cra_type = &crypto_blkcipher_type;
214
Herbert Xu5311f242007-12-17 21:34:32 +0800215 inst->alg.cra_blkcipher.ivsize = alg->cra_blocksize;
216 inst->alg.cra_blkcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
217 inst->alg.cra_blkcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
Joy Latten23e353c2007-10-23 08:50:32 +0800218
219 inst->alg.cra_ctxsize = sizeof(struct crypto_ctr_ctx);
220
221 inst->alg.cra_init = crypto_ctr_init_tfm;
222 inst->alg.cra_exit = crypto_ctr_exit_tfm;
223
224 inst->alg.cra_blkcipher.setkey = crypto_ctr_setkey;
225 inst->alg.cra_blkcipher.encrypt = crypto_ctr_crypt;
226 inst->alg.cra_blkcipher.decrypt = crypto_ctr_crypt;
227
Herbert Xuaef27132009-08-13 23:10:39 +1000228 inst->alg.cra_blkcipher.geniv = "chainiv";
229
Herbert Xu5311f242007-12-17 21:34:32 +0800230out:
231 crypto_mod_put(alg);
232 return inst;
Joy Latten23e353c2007-10-23 08:50:32 +0800233
234out_put_alg:
Herbert Xu5311f242007-12-17 21:34:32 +0800235 inst = ERR_PTR(err);
236 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800237}
238
239static void crypto_ctr_free(struct crypto_instance *inst)
240{
Herbert Xu5311f242007-12-17 21:34:32 +0800241 crypto_drop_spawn(crypto_instance_ctx(inst));
Joy Latten23e353c2007-10-23 08:50:32 +0800242 kfree(inst);
243}
244
245static struct crypto_template crypto_ctr_tmpl = {
246 .name = "ctr",
247 .alloc = crypto_ctr_alloc,
248 .free = crypto_ctr_free,
249 .module = THIS_MODULE,
250};
251
Herbert Xub2b39c22016-07-12 13:17:37 +0800252static int crypto_rfc3686_setkey(struct crypto_skcipher *parent,
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200253 const u8 *key, unsigned int keylen)
Herbert Xu5311f242007-12-17 21:34:32 +0800254{
Herbert Xub2b39c22016-07-12 13:17:37 +0800255 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(parent);
256 struct crypto_skcipher *child = ctx->child;
Herbert Xu5311f242007-12-17 21:34:32 +0800257 int err;
258
259 /* the nonce is stored in bytes at end of key */
260 if (keylen < CTR_RFC3686_NONCE_SIZE)
261 return -EINVAL;
262
263 memcpy(ctx->nonce, key + (keylen - CTR_RFC3686_NONCE_SIZE),
264 CTR_RFC3686_NONCE_SIZE);
265
266 keylen -= CTR_RFC3686_NONCE_SIZE;
267
Herbert Xub2b39c22016-07-12 13:17:37 +0800268 crypto_skcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
269 crypto_skcipher_set_flags(child, crypto_skcipher_get_flags(parent) &
270 CRYPTO_TFM_REQ_MASK);
271 err = crypto_skcipher_setkey(child, key, keylen);
272 crypto_skcipher_set_flags(parent, crypto_skcipher_get_flags(child) &
273 CRYPTO_TFM_RES_MASK);
Herbert Xu5311f242007-12-17 21:34:32 +0800274
275 return err;
276}
277
Herbert Xub2b39c22016-07-12 13:17:37 +0800278static int crypto_rfc3686_crypt(struct skcipher_request *req)
Herbert Xu5311f242007-12-17 21:34:32 +0800279{
Herbert Xub2b39c22016-07-12 13:17:37 +0800280 struct crypto_skcipher *tfm = crypto_skcipher_reqtfm(req);
281 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
282 struct crypto_skcipher *child = ctx->child;
283 unsigned long align = crypto_skcipher_alignmask(tfm);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200284 struct crypto_rfc3686_req_ctx *rctx =
Herbert Xub2b39c22016-07-12 13:17:37 +0800285 (void *)PTR_ALIGN((u8 *)skcipher_request_ctx(req), align + 1);
286 struct skcipher_request *subreq = &rctx->subreq;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200287 u8 *iv = rctx->iv;
Herbert Xu5311f242007-12-17 21:34:32 +0800288
289 /* set up counter block */
290 memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
Herbert Xub2b39c22016-07-12 13:17:37 +0800291 memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->iv, CTR_RFC3686_IV_SIZE);
Herbert Xu5311f242007-12-17 21:34:32 +0800292
293 /* initialize counter portion of counter block */
294 *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
295 cpu_to_be32(1);
296
Herbert Xub2b39c22016-07-12 13:17:37 +0800297 skcipher_request_set_tfm(subreq, child);
298 skcipher_request_set_callback(subreq, req->base.flags,
299 req->base.complete, req->base.data);
300 skcipher_request_set_crypt(subreq, req->src, req->dst,
301 req->cryptlen, iv);
Herbert Xu5311f242007-12-17 21:34:32 +0800302
Herbert Xub2b39c22016-07-12 13:17:37 +0800303 return crypto_skcipher_encrypt(subreq);
Herbert Xu5311f242007-12-17 21:34:32 +0800304}
305
Herbert Xub2b39c22016-07-12 13:17:37 +0800306static int crypto_rfc3686_init_tfm(struct crypto_skcipher *tfm)
Herbert Xu5311f242007-12-17 21:34:32 +0800307{
Herbert Xub2b39c22016-07-12 13:17:37 +0800308 struct skcipher_instance *inst = skcipher_alg_instance(tfm);
309 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
310 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
311 struct crypto_skcipher *cipher;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200312 unsigned long align;
Herbert Xub2b39c22016-07-12 13:17:37 +0800313 unsigned int reqsize;
Herbert Xu5311f242007-12-17 21:34:32 +0800314
Eric Biggers60425a82016-10-28 09:52:19 -0700315 cipher = crypto_spawn_skcipher(spawn);
Herbert Xu5311f242007-12-17 21:34:32 +0800316 if (IS_ERR(cipher))
317 return PTR_ERR(cipher);
318
319 ctx->child = cipher;
320
Herbert Xub2b39c22016-07-12 13:17:37 +0800321 align = crypto_skcipher_alignmask(tfm);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200322 align &= ~(crypto_tfm_ctx_alignment() - 1);
Herbert Xub2b39c22016-07-12 13:17:37 +0800323 reqsize = align + sizeof(struct crypto_rfc3686_req_ctx) +
324 crypto_skcipher_reqsize(cipher);
325 crypto_skcipher_set_reqsize(tfm, reqsize);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200326
Herbert Xu5311f242007-12-17 21:34:32 +0800327 return 0;
328}
329
Herbert Xub2b39c22016-07-12 13:17:37 +0800330static void crypto_rfc3686_exit_tfm(struct crypto_skcipher *tfm)
Herbert Xu5311f242007-12-17 21:34:32 +0800331{
Herbert Xub2b39c22016-07-12 13:17:37 +0800332 struct crypto_rfc3686_ctx *ctx = crypto_skcipher_ctx(tfm);
Herbert Xu5311f242007-12-17 21:34:32 +0800333
Herbert Xub2b39c22016-07-12 13:17:37 +0800334 crypto_free_skcipher(ctx->child);
Herbert Xu5311f242007-12-17 21:34:32 +0800335}
336
Herbert Xub2b39c22016-07-12 13:17:37 +0800337static void crypto_rfc3686_free(struct skcipher_instance *inst)
338{
339 struct crypto_skcipher_spawn *spawn = skcipher_instance_ctx(inst);
340
341 crypto_drop_skcipher(spawn);
342 kfree(inst);
343}
344
345static int crypto_rfc3686_create(struct crypto_template *tmpl,
346 struct rtattr **tb)
Herbert Xu5311f242007-12-17 21:34:32 +0800347{
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200348 struct crypto_attr_type *algt;
Herbert Xub2b39c22016-07-12 13:17:37 +0800349 struct skcipher_instance *inst;
350 struct skcipher_alg *alg;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200351 struct crypto_skcipher_spawn *spawn;
352 const char *cipher_name;
Herbert Xu5311f242007-12-17 21:34:32 +0800353 int err;
354
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200355 algt = crypto_get_attr_type(tb);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200356 if (IS_ERR(algt))
Herbert Xub2b39c22016-07-12 13:17:37 +0800357 return PTR_ERR(algt);
Herbert Xu5311f242007-12-17 21:34:32 +0800358
Herbert Xub2b39c22016-07-12 13:17:37 +0800359 if ((algt->type ^ CRYPTO_ALG_TYPE_SKCIPHER) & algt->mask)
360 return -EINVAL;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200361
362 cipher_name = crypto_attr_alg_name(tb[1]);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200363 if (IS_ERR(cipher_name))
Herbert Xub2b39c22016-07-12 13:17:37 +0800364 return PTR_ERR(cipher_name);
Herbert Xu5311f242007-12-17 21:34:32 +0800365
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200366 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
367 if (!inst)
Herbert Xub2b39c22016-07-12 13:17:37 +0800368 return -ENOMEM;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200369
Herbert Xub2b39c22016-07-12 13:17:37 +0800370 spawn = skcipher_instance_ctx(inst);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200371
Herbert Xub2b39c22016-07-12 13:17:37 +0800372 crypto_set_skcipher_spawn(spawn, skcipher_crypto_instance(inst));
Eric Biggersa35528e2016-10-28 09:51:13 -0700373 err = crypto_grab_skcipher(spawn, cipher_name, 0,
374 crypto_requires_sync(algt->type,
375 algt->mask));
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200376 if (err)
377 goto err_free_inst;
378
Herbert Xub2b39c22016-07-12 13:17:37 +0800379 alg = crypto_spawn_skcipher_alg(spawn);
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200380
Herbert Xu5311f242007-12-17 21:34:32 +0800381 /* We only support 16-byte blocks. */
382 err = -EINVAL;
Herbert Xub2b39c22016-07-12 13:17:37 +0800383 if (crypto_skcipher_alg_ivsize(alg) != CTR_RFC3686_BLOCK_SIZE)
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200384 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800385
386 /* Not a stream cipher? */
Herbert Xub2b39c22016-07-12 13:17:37 +0800387 if (alg->base.cra_blocksize != 1)
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200388 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800389
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200390 err = -ENAMETOOLONG;
Herbert Xub2b39c22016-07-12 13:17:37 +0800391 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
392 "rfc3686(%s)", alg->base.cra_name) >= CRYPTO_MAX_ALG_NAME)
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200393 goto err_drop_spawn;
Herbert Xub2b39c22016-07-12 13:17:37 +0800394 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
395 "rfc3686(%s)", alg->base.cra_driver_name) >=
396 CRYPTO_MAX_ALG_NAME)
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200397 goto err_drop_spawn;
Herbert Xu5311f242007-12-17 21:34:32 +0800398
Herbert Xub2b39c22016-07-12 13:17:37 +0800399 inst->alg.base.cra_priority = alg->base.cra_priority;
400 inst->alg.base.cra_blocksize = 1;
401 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
Herbert Xu5311f242007-12-17 21:34:32 +0800402
Herbert Xub2b39c22016-07-12 13:17:37 +0800403 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
Herbert Xu5311f242007-12-17 21:34:32 +0800404
Herbert Xub2b39c22016-07-12 13:17:37 +0800405 inst->alg.ivsize = CTR_RFC3686_IV_SIZE;
406 inst->alg.chunksize = crypto_skcipher_alg_chunksize(alg);
407 inst->alg.min_keysize = crypto_skcipher_alg_min_keysize(alg) +
408 CTR_RFC3686_NONCE_SIZE;
409 inst->alg.max_keysize = crypto_skcipher_alg_max_keysize(alg) +
410 CTR_RFC3686_NONCE_SIZE;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200411
Herbert Xub2b39c22016-07-12 13:17:37 +0800412 inst->alg.setkey = crypto_rfc3686_setkey;
413 inst->alg.encrypt = crypto_rfc3686_crypt;
414 inst->alg.decrypt = crypto_rfc3686_crypt;
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200415
Herbert Xub2b39c22016-07-12 13:17:37 +0800416 inst->alg.base.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
Herbert Xu0a270322007-11-30 21:38:37 +1100417
Herbert Xub2b39c22016-07-12 13:17:37 +0800418 inst->alg.init = crypto_rfc3686_init_tfm;
419 inst->alg.exit = crypto_rfc3686_exit_tfm;
Herbert Xu5311f242007-12-17 21:34:32 +0800420
Herbert Xub2b39c22016-07-12 13:17:37 +0800421 inst->free = crypto_rfc3686_free;
Herbert Xu5311f242007-12-17 21:34:32 +0800422
Herbert Xub2b39c22016-07-12 13:17:37 +0800423 err = skcipher_register_instance(tmpl, inst);
424 if (err)
425 goto err_drop_spawn;
426
427out:
428 return err;
Herbert Xu5311f242007-12-17 21:34:32 +0800429
Jussi Kivilinna69d31502012-12-28 12:04:58 +0200430err_drop_spawn:
431 crypto_drop_skcipher(spawn);
432err_free_inst:
433 kfree(inst);
Herbert Xub2b39c22016-07-12 13:17:37 +0800434 goto out;
Herbert Xu5311f242007-12-17 21:34:32 +0800435}
436
437static struct crypto_template crypto_rfc3686_tmpl = {
438 .name = "rfc3686",
Herbert Xub2b39c22016-07-12 13:17:37 +0800439 .create = crypto_rfc3686_create,
Herbert Xu5311f242007-12-17 21:34:32 +0800440 .module = THIS_MODULE,
441};
442
Joy Latten23e353c2007-10-23 08:50:32 +0800443static int __init crypto_ctr_module_init(void)
444{
Herbert Xu5311f242007-12-17 21:34:32 +0800445 int err;
446
447 err = crypto_register_template(&crypto_ctr_tmpl);
448 if (err)
449 goto out;
450
451 err = crypto_register_template(&crypto_rfc3686_tmpl);
452 if (err)
453 goto out_drop_ctr;
454
455out:
456 return err;
457
458out_drop_ctr:
459 crypto_unregister_template(&crypto_ctr_tmpl);
460 goto out;
Joy Latten23e353c2007-10-23 08:50:32 +0800461}
462
463static void __exit crypto_ctr_module_exit(void)
464{
Herbert Xu5311f242007-12-17 21:34:32 +0800465 crypto_unregister_template(&crypto_rfc3686_tmpl);
Joy Latten23e353c2007-10-23 08:50:32 +0800466 crypto_unregister_template(&crypto_ctr_tmpl);
467}
468
469module_init(crypto_ctr_module_init);
470module_exit(crypto_ctr_module_exit);
471
472MODULE_LICENSE("GPL");
473MODULE_DESCRIPTION("CTR Counter block mode");
Kees Cook5d26a102014-11-20 17:05:53 -0800474MODULE_ALIAS_CRYPTO("rfc3686");
Kees Cook4943ba12014-11-24 16:32:38 -0800475MODULE_ALIAS_CRYPTO("ctr");