crypto: serpent - add AVX2/x86_64 assembler implementation of serpent cipher
[linux-3.10.git] / crypto / ctr.c
1 /*
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>
14 #include <crypto/ctr.h>
15 #include <crypto/internal/skcipher.h>
16 #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
24 struct crypto_ctr_ctx {
25         struct crypto_cipher *child;
26 };
27
28 struct crypto_rfc3686_ctx {
29         struct crypto_ablkcipher *child;
30         u8 nonce[CTR_RFC3686_NONCE_SIZE];
31 };
32
33 struct crypto_rfc3686_req_ctx {
34         u8 iv[CTR_RFC3686_BLOCK_SIZE];
35         struct ablkcipher_request subreq CRYPTO_MINALIGN_ATTR;
36 };
37
38 static 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;
43         int err;
44
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
55 static void crypto_ctr_crypt_final(struct blkcipher_walk *walk,
56                                    struct crypto_cipher *tfm)
57 {
58         unsigned int bsize = crypto_cipher_blocksize(tfm);
59         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);
63         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);
70
71         crypto_inc(ctrblk, bsize);
72 }
73
74 static int crypto_ctr_crypt_segment(struct blkcipher_walk *walk,
75                                     struct crypto_cipher *tfm)
76 {
77         void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
78                    crypto_cipher_alg(tfm)->cia_encrypt;
79         unsigned int bsize = crypto_cipher_blocksize(tfm);
80         u8 *ctrblk = walk->iv;
81         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 */
87                 fn(crypto_cipher_tfm(tfm), dst, ctrblk);
88                 crypto_xor(dst, src, bsize);
89
90                 /* increment counter in counterblock */
91                 crypto_inc(ctrblk, bsize);
92
93                 src += bsize;
94                 dst += bsize;
95         } while ((nbytes -= bsize) >= bsize);
96
97         return nbytes;
98 }
99
100 static int crypto_ctr_crypt_inplace(struct blkcipher_walk *walk,
101                                     struct crypto_cipher *tfm)
102 {
103         void (*fn)(struct crypto_tfm *, u8 *, const u8 *) =
104                    crypto_cipher_alg(tfm)->cia_encrypt;
105         unsigned int bsize = crypto_cipher_blocksize(tfm);
106         unsigned long alignmask = crypto_cipher_alignmask(tfm);
107         unsigned int nbytes = walk->nbytes;
108         u8 *ctrblk = walk->iv;
109         u8 *src = walk->src.virt.addr;
110         u8 tmp[bsize + alignmask];
111         u8 *keystream = PTR_ALIGN(tmp + 0, alignmask + 1);
112
113         do {
114                 /* create keystream */
115                 fn(crypto_cipher_tfm(tfm), keystream, ctrblk);
116                 crypto_xor(src, keystream, bsize);
117
118                 /* increment counter in counterblock */
119                 crypto_inc(ctrblk, bsize);
120
121                 src += bsize;
122         } while ((nbytes -= bsize) >= bsize);
123
124         return nbytes;
125 }
126
127 static 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);
136         int err;
137
138         blkcipher_walk_init(&walk, dst, src, nbytes);
139         err = blkcipher_walk_virt_block(desc, &walk, bsize);
140
141         while (walk.nbytes >= bsize) {
142                 if (walk.src.virt.addr == walk.dst.virt.addr)
143                         nbytes = crypto_ctr_crypt_inplace(&walk, child);
144                 else
145                         nbytes = crypto_ctr_crypt_segment(&walk, child);
146
147                 err = blkcipher_walk_done(desc, &walk, nbytes);
148         }
149
150         if (walk.nbytes) {
151                 crypto_ctr_crypt_final(&walk, child);
152                 err = blkcipher_walk_done(desc, &walk, 0);
153         }
154
155         return err;
156 }
157
158 static int crypto_ctr_init_tfm(struct crypto_tfm *tfm)
159 {
160         struct crypto_instance *inst = (void *)tfm->__crt_alg;
161         struct crypto_spawn *spawn = crypto_instance_ctx(inst);
162         struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
163         struct crypto_cipher *cipher;
164
165         cipher = crypto_spawn_cipher(spawn);
166         if (IS_ERR(cipher))
167                 return PTR_ERR(cipher);
168
169         ctx->child = cipher;
170
171         return 0;
172 }
173
174 static void crypto_ctr_exit_tfm(struct crypto_tfm *tfm)
175 {
176         struct crypto_ctr_ctx *ctx = crypto_tfm_ctx(tfm);
177
178         crypto_free_cipher(ctx->child);
179 }
180
181 static struct crypto_instance *crypto_ctr_alloc(struct rtattr **tb)
182 {
183         struct crypto_instance *inst;
184         struct crypto_alg *alg;
185         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))
194                 return ERR_CAST(alg);
195
196         /* Block size must be >= 4 bytes. */
197         err = -EINVAL;
198         if (alg->cra_blocksize < 4)
199                 goto out_put_alg;
200
201         /* If this is false we'd fail the alignment of crypto_inc. */
202         if (alg->cra_blocksize % 4)
203                 goto out_put_alg;
204
205         inst = crypto_alloc_instance("ctr", alg);
206         if (IS_ERR(inst))
207                 goto out;
208
209         inst->alg.cra_flags = CRYPTO_ALG_TYPE_BLKCIPHER;
210         inst->alg.cra_priority = alg->cra_priority;
211         inst->alg.cra_blocksize = 1;
212         inst->alg.cra_alignmask = alg->cra_alignmask | (__alignof__(u32) - 1);
213         inst->alg.cra_type = &crypto_blkcipher_type;
214
215         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;
218
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
228         inst->alg.cra_blkcipher.geniv = "chainiv";
229
230 out:
231         crypto_mod_put(alg);
232         return inst;
233
234 out_put_alg:
235         inst = ERR_PTR(err);
236         goto out;
237 }
238
239 static void crypto_ctr_free(struct crypto_instance *inst)
240 {
241         crypto_drop_spawn(crypto_instance_ctx(inst));
242         kfree(inst);
243 }
244
245 static 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
252 static int crypto_rfc3686_setkey(struct crypto_ablkcipher *parent,
253                                  const u8 *key, unsigned int keylen)
254 {
255         struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(parent);
256         struct crypto_ablkcipher *child = ctx->child;
257         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
268         crypto_ablkcipher_clear_flags(child, CRYPTO_TFM_REQ_MASK);
269         crypto_ablkcipher_set_flags(child, crypto_ablkcipher_get_flags(parent) &
270                                     CRYPTO_TFM_REQ_MASK);
271         err = crypto_ablkcipher_setkey(child, key, keylen);
272         crypto_ablkcipher_set_flags(parent, crypto_ablkcipher_get_flags(child) &
273                                     CRYPTO_TFM_RES_MASK);
274
275         return err;
276 }
277
278 static int crypto_rfc3686_crypt(struct ablkcipher_request *req)
279 {
280         struct crypto_ablkcipher *tfm = crypto_ablkcipher_reqtfm(req);
281         struct crypto_rfc3686_ctx *ctx = crypto_ablkcipher_ctx(tfm);
282         struct crypto_ablkcipher *child = ctx->child;
283         unsigned long align = crypto_ablkcipher_alignmask(tfm);
284         struct crypto_rfc3686_req_ctx *rctx =
285                 (void *)PTR_ALIGN((u8 *)ablkcipher_request_ctx(req), align + 1);
286         struct ablkcipher_request *subreq = &rctx->subreq;
287         u8 *iv = rctx->iv;
288
289         /* set up counter block */
290         memcpy(iv, ctx->nonce, CTR_RFC3686_NONCE_SIZE);
291         memcpy(iv + CTR_RFC3686_NONCE_SIZE, req->info, CTR_RFC3686_IV_SIZE);
292
293         /* initialize counter portion of counter block */
294         *(__be32 *)(iv + CTR_RFC3686_NONCE_SIZE + CTR_RFC3686_IV_SIZE) =
295                 cpu_to_be32(1);
296
297         ablkcipher_request_set_tfm(subreq, child);
298         ablkcipher_request_set_callback(subreq, req->base.flags,
299                                         req->base.complete, req->base.data);
300         ablkcipher_request_set_crypt(subreq, req->src, req->dst, req->nbytes,
301                                      iv);
302
303         return crypto_ablkcipher_encrypt(subreq);
304 }
305
306 static int crypto_rfc3686_init_tfm(struct crypto_tfm *tfm)
307 {
308         struct crypto_instance *inst = (void *)tfm->__crt_alg;
309         struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);
310         struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
311         struct crypto_ablkcipher *cipher;
312         unsigned long align;
313
314         cipher = crypto_spawn_skcipher(spawn);
315         if (IS_ERR(cipher))
316                 return PTR_ERR(cipher);
317
318         ctx->child = cipher;
319
320         align = crypto_tfm_alg_alignmask(tfm);
321         align &= ~(crypto_tfm_ctx_alignment() - 1);
322         tfm->crt_ablkcipher.reqsize = align +
323                 sizeof(struct crypto_rfc3686_req_ctx) +
324                 crypto_ablkcipher_reqsize(cipher);
325
326         return 0;
327 }
328
329 static void crypto_rfc3686_exit_tfm(struct crypto_tfm *tfm)
330 {
331         struct crypto_rfc3686_ctx *ctx = crypto_tfm_ctx(tfm);
332
333         crypto_free_ablkcipher(ctx->child);
334 }
335
336 static struct crypto_instance *crypto_rfc3686_alloc(struct rtattr **tb)
337 {
338         struct crypto_attr_type *algt;
339         struct crypto_instance *inst;
340         struct crypto_alg *alg;
341         struct crypto_skcipher_spawn *spawn;
342         const char *cipher_name;
343         int err;
344
345         algt = crypto_get_attr_type(tb);
346         if (IS_ERR(algt))
347                 return ERR_CAST(algt);
348
349         if ((algt->type ^ CRYPTO_ALG_TYPE_BLKCIPHER) & algt->mask)
350                 return ERR_PTR(-EINVAL);
351
352         cipher_name = crypto_attr_alg_name(tb[1]);
353         if (IS_ERR(cipher_name))
354                 return ERR_CAST(cipher_name);
355
356         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
357         if (!inst)
358                 return ERR_PTR(-ENOMEM);
359
360         spawn = crypto_instance_ctx(inst);
361
362         crypto_set_skcipher_spawn(spawn, inst);
363         err = crypto_grab_skcipher(spawn, cipher_name, 0,
364                                    crypto_requires_sync(algt->type,
365                                                         algt->mask));
366         if (err)
367                 goto err_free_inst;
368
369         alg = crypto_skcipher_spawn_alg(spawn);
370
371         /* We only support 16-byte blocks. */
372         err = -EINVAL;
373         if (alg->cra_ablkcipher.ivsize != CTR_RFC3686_BLOCK_SIZE)
374                 goto err_drop_spawn;
375
376         /* Not a stream cipher? */
377         if (alg->cra_blocksize != 1)
378                 goto err_drop_spawn;
379
380         err = -ENAMETOOLONG;
381         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "rfc3686(%s)",
382                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
383                 goto err_drop_spawn;
384         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
385                      "rfc3686(%s)", alg->cra_driver_name) >=
386                         CRYPTO_MAX_ALG_NAME)
387                 goto err_drop_spawn;
388
389         inst->alg.cra_priority = alg->cra_priority;
390         inst->alg.cra_blocksize = 1;
391         inst->alg.cra_alignmask = alg->cra_alignmask;
392
393         inst->alg.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER |
394                               (alg->cra_flags & CRYPTO_ALG_ASYNC);
395         inst->alg.cra_type = &crypto_ablkcipher_type;
396
397         inst->alg.cra_ablkcipher.ivsize = CTR_RFC3686_IV_SIZE;
398         inst->alg.cra_ablkcipher.min_keysize =
399                 alg->cra_ablkcipher.min_keysize + CTR_RFC3686_NONCE_SIZE;
400         inst->alg.cra_ablkcipher.max_keysize =
401                 alg->cra_ablkcipher.max_keysize + CTR_RFC3686_NONCE_SIZE;
402
403         inst->alg.cra_ablkcipher.geniv = "seqiv";
404
405         inst->alg.cra_ablkcipher.setkey = crypto_rfc3686_setkey;
406         inst->alg.cra_ablkcipher.encrypt = crypto_rfc3686_crypt;
407         inst->alg.cra_ablkcipher.decrypt = crypto_rfc3686_crypt;
408
409         inst->alg.cra_ctxsize = sizeof(struct crypto_rfc3686_ctx);
410
411         inst->alg.cra_init = crypto_rfc3686_init_tfm;
412         inst->alg.cra_exit = crypto_rfc3686_exit_tfm;
413
414         return inst;
415
416 err_drop_spawn:
417         crypto_drop_skcipher(spawn);
418 err_free_inst:
419         kfree(inst);
420         return ERR_PTR(err);
421 }
422
423 static void crypto_rfc3686_free(struct crypto_instance *inst)
424 {
425         struct crypto_skcipher_spawn *spawn = crypto_instance_ctx(inst);
426
427         crypto_drop_skcipher(spawn);
428         kfree(inst);
429 }
430
431 static struct crypto_template crypto_rfc3686_tmpl = {
432         .name = "rfc3686",
433         .alloc = crypto_rfc3686_alloc,
434         .free = crypto_rfc3686_free,
435         .module = THIS_MODULE,
436 };
437
438 static int __init crypto_ctr_module_init(void)
439 {
440         int err;
441
442         err = crypto_register_template(&crypto_ctr_tmpl);
443         if (err)
444                 goto out;
445
446         err = crypto_register_template(&crypto_rfc3686_tmpl);
447         if (err)
448                 goto out_drop_ctr;
449
450 out:
451         return err;
452
453 out_drop_ctr:
454         crypto_unregister_template(&crypto_ctr_tmpl);
455         goto out;
456 }
457
458 static void __exit crypto_ctr_module_exit(void)
459 {
460         crypto_unregister_template(&crypto_rfc3686_tmpl);
461         crypto_unregister_template(&crypto_ctr_tmpl);
462 }
463
464 module_init(crypto_ctr_module_init);
465 module_exit(crypto_ctr_module_exit);
466
467 MODULE_LICENSE("GPL");
468 MODULE_DESCRIPTION("CTR Counter block mode");
469 MODULE_ALIAS("rfc3686");