1 /*
2 * AEAD: Authenticated Encryption with Associated Data
3 *
4 * This file provides API support for AEAD algorithms.
5 *
6 * Copyright (c) 2007 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <crypto/internal/aead.h>
16 #include <linux/err.h>
17 #include <linux/init.h>
18 #include <linux/kernel.h>
19 #include <linux/module.h>
20 #include <linux/rtnetlink.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/seq_file.h>
24
25 #include "internal.h"
26
setkey_unaligned(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)27 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
28 unsigned int keylen)
29 {
30 struct aead_alg *aead = crypto_aead_alg(tfm);
31 unsigned long alignmask = crypto_aead_alignmask(tfm);
32 int ret;
33 u8 *buffer, *alignbuffer;
34 unsigned long absize;
35
36 absize = keylen + alignmask;
37 buffer = kmalloc(absize, GFP_ATOMIC);
38 if (!buffer)
39 return -ENOMEM;
40
41 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
42 memcpy(alignbuffer, key, keylen);
43 ret = aead->setkey(tfm, alignbuffer, keylen);
44 memset(alignbuffer, 0, keylen);
45 kfree(buffer);
46 return ret;
47 }
48
setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)49 static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
50 {
51 struct aead_alg *aead = crypto_aead_alg(tfm);
52 unsigned long alignmask = crypto_aead_alignmask(tfm);
53
54 if ((unsigned long)key & alignmask)
55 return setkey_unaligned(tfm, key, keylen);
56
57 return aead->setkey(tfm, key, keylen);
58 }
59
crypto_aead_setauthsize(struct crypto_aead * tfm,unsigned int authsize)60 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
61 {
62 struct aead_tfm *crt = crypto_aead_crt(tfm);
63 int err;
64
65 if (authsize > crypto_aead_alg(tfm)->maxauthsize)
66 return -EINVAL;
67
68 if (crypto_aead_alg(tfm)->setauthsize) {
69 err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
70 if (err)
71 return err;
72 }
73
74 crypto_aead_crt(crt->base)->authsize = authsize;
75 crt->authsize = authsize;
76 return 0;
77 }
78 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
79
crypto_aead_ctxsize(struct crypto_alg * alg,u32 type,u32 mask)80 static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
81 u32 mask)
82 {
83 return alg->cra_ctxsize;
84 }
85
no_givcrypt(struct aead_givcrypt_request * req)86 static int no_givcrypt(struct aead_givcrypt_request *req)
87 {
88 return -ENOSYS;
89 }
90
crypto_init_aead_ops(struct crypto_tfm * tfm,u32 type,u32 mask)91 static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
92 {
93 struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
94 struct aead_tfm *crt = &tfm->crt_aead;
95
96 if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
97 return -EINVAL;
98
99 crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
100 alg->setkey : setkey;
101 crt->encrypt = alg->encrypt;
102 crt->decrypt = alg->decrypt;
103 crt->givencrypt = alg->givencrypt ?: no_givcrypt;
104 crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
105 crt->base = __crypto_aead_cast(tfm);
106 crt->ivsize = alg->ivsize;
107 crt->authsize = alg->maxauthsize;
108
109 return 0;
110 }
111
112 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
113 __attribute__ ((unused));
crypto_aead_show(struct seq_file * m,struct crypto_alg * alg)114 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
115 {
116 struct aead_alg *aead = &alg->cra_aead;
117
118 seq_printf(m, "type : aead\n");
119 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
120 "yes" : "no");
121 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
122 seq_printf(m, "ivsize : %u\n", aead->ivsize);
123 seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
124 seq_printf(m, "geniv : %s\n", aead->geniv ?: "<built-in>");
125 }
126
127 const struct crypto_type crypto_aead_type = {
128 .ctxsize = crypto_aead_ctxsize,
129 .init = crypto_init_aead_ops,
130 #ifdef CONFIG_PROC_FS
131 .show = crypto_aead_show,
132 #endif
133 };
134 EXPORT_SYMBOL_GPL(crypto_aead_type);
135
aead_null_givencrypt(struct aead_givcrypt_request * req)136 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
137 {
138 return crypto_aead_encrypt(&req->areq);
139 }
140
aead_null_givdecrypt(struct aead_givcrypt_request * req)141 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
142 {
143 return crypto_aead_decrypt(&req->areq);
144 }
145
crypto_init_nivaead_ops(struct crypto_tfm * tfm,u32 type,u32 mask)146 static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
147 {
148 struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
149 struct aead_tfm *crt = &tfm->crt_aead;
150
151 if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
152 return -EINVAL;
153
154 crt->setkey = setkey;
155 crt->encrypt = alg->encrypt;
156 crt->decrypt = alg->decrypt;
157 if (!alg->ivsize) {
158 crt->givencrypt = aead_null_givencrypt;
159 crt->givdecrypt = aead_null_givdecrypt;
160 }
161 crt->base = __crypto_aead_cast(tfm);
162 crt->ivsize = alg->ivsize;
163 crt->authsize = alg->maxauthsize;
164
165 return 0;
166 }
167
168 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
169 __attribute__ ((unused));
crypto_nivaead_show(struct seq_file * m,struct crypto_alg * alg)170 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
171 {
172 struct aead_alg *aead = &alg->cra_aead;
173
174 seq_printf(m, "type : nivaead\n");
175 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
176 "yes" : "no");
177 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
178 seq_printf(m, "ivsize : %u\n", aead->ivsize);
179 seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
180 seq_printf(m, "geniv : %s\n", aead->geniv);
181 }
182
183 const struct crypto_type crypto_nivaead_type = {
184 .ctxsize = crypto_aead_ctxsize,
185 .init = crypto_init_nivaead_ops,
186 #ifdef CONFIG_PROC_FS
187 .show = crypto_nivaead_show,
188 #endif
189 };
190 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
191
crypto_grab_nivaead(struct crypto_aead_spawn * spawn,const char * name,u32 type,u32 mask)192 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
193 const char *name, u32 type, u32 mask)
194 {
195 struct crypto_alg *alg;
196 int err;
197
198 type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
199 type |= CRYPTO_ALG_TYPE_AEAD;
200 mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
201
202 alg = crypto_alg_mod_lookup(name, type, mask);
203 if (IS_ERR(alg))
204 return PTR_ERR(alg);
205
206 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
207 crypto_mod_put(alg);
208 return err;
209 }
210
aead_geniv_alloc(struct crypto_template * tmpl,struct rtattr ** tb,u32 type,u32 mask)211 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
212 struct rtattr **tb, u32 type,
213 u32 mask)
214 {
215 const char *name;
216 struct crypto_aead_spawn *spawn;
217 struct crypto_attr_type *algt;
218 struct crypto_instance *inst;
219 struct crypto_alg *alg;
220 int err;
221
222 algt = crypto_get_attr_type(tb);
223 err = PTR_ERR(algt);
224 if (IS_ERR(algt))
225 return ERR_PTR(err);
226
227 if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
228 algt->mask)
229 return ERR_PTR(-EINVAL);
230
231 name = crypto_attr_alg_name(tb[1]);
232 err = PTR_ERR(name);
233 if (IS_ERR(name))
234 return ERR_PTR(err);
235
236 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
237 if (!inst)
238 return ERR_PTR(-ENOMEM);
239
240 spawn = crypto_instance_ctx(inst);
241
242 /* Ignore async algorithms if necessary. */
243 mask |= crypto_requires_sync(algt->type, algt->mask);
244
245 crypto_set_aead_spawn(spawn, inst);
246 err = crypto_grab_nivaead(spawn, name, type, mask);
247 if (err)
248 goto err_free_inst;
249
250 alg = crypto_aead_spawn_alg(spawn);
251
252 err = -EINVAL;
253 if (!alg->cra_aead.ivsize)
254 goto err_drop_alg;
255
256 /*
257 * This is only true if we're constructing an algorithm with its
258 * default IV generator. For the default generator we elide the
259 * template name and double-check the IV generator.
260 */
261 if (algt->mask & CRYPTO_ALG_GENIV) {
262 if (strcmp(tmpl->name, alg->cra_aead.geniv))
263 goto err_drop_alg;
264
265 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
266 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
267 CRYPTO_MAX_ALG_NAME);
268 } else {
269 err = -ENAMETOOLONG;
270 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
271 "%s(%s)", tmpl->name, alg->cra_name) >=
272 CRYPTO_MAX_ALG_NAME)
273 goto err_drop_alg;
274 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
275 "%s(%s)", tmpl->name, alg->cra_driver_name) >=
276 CRYPTO_MAX_ALG_NAME)
277 goto err_drop_alg;
278 }
279
280 inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
281 inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
282 inst->alg.cra_priority = alg->cra_priority;
283 inst->alg.cra_blocksize = alg->cra_blocksize;
284 inst->alg.cra_alignmask = alg->cra_alignmask;
285 inst->alg.cra_type = &crypto_aead_type;
286
287 inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
288 inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
289 inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
290
291 inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
292 inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
293 inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
294 inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
295
296 out:
297 return inst;
298
299 err_drop_alg:
300 crypto_drop_aead(spawn);
301 err_free_inst:
302 kfree(inst);
303 inst = ERR_PTR(err);
304 goto out;
305 }
306 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
307
aead_geniv_free(struct crypto_instance * inst)308 void aead_geniv_free(struct crypto_instance *inst)
309 {
310 crypto_drop_aead(crypto_instance_ctx(inst));
311 kfree(inst);
312 }
313 EXPORT_SYMBOL_GPL(aead_geniv_free);
314
aead_geniv_init(struct crypto_tfm * tfm)315 int aead_geniv_init(struct crypto_tfm *tfm)
316 {
317 struct crypto_instance *inst = (void *)tfm->__crt_alg;
318 struct crypto_aead *aead;
319
320 aead = crypto_spawn_aead(crypto_instance_ctx(inst));
321 if (IS_ERR(aead))
322 return PTR_ERR(aead);
323
324 tfm->crt_aead.base = aead;
325 tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
326
327 return 0;
328 }
329 EXPORT_SYMBOL_GPL(aead_geniv_init);
330
aead_geniv_exit(struct crypto_tfm * tfm)331 void aead_geniv_exit(struct crypto_tfm *tfm)
332 {
333 crypto_free_aead(tfm->crt_aead.base);
334 }
335 EXPORT_SYMBOL_GPL(aead_geniv_exit);
336
crypto_nivaead_default(struct crypto_alg * alg,u32 type,u32 mask)337 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
338 {
339 struct rtattr *tb[3];
340 struct {
341 struct rtattr attr;
342 struct crypto_attr_type data;
343 } ptype;
344 struct {
345 struct rtattr attr;
346 struct crypto_attr_alg data;
347 } palg;
348 struct crypto_template *tmpl;
349 struct crypto_instance *inst;
350 struct crypto_alg *larval;
351 const char *geniv;
352 int err;
353
354 larval = crypto_larval_lookup(alg->cra_driver_name,
355 CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
356 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
357 err = PTR_ERR(larval);
358 if (IS_ERR(larval))
359 goto out;
360
361 err = -EAGAIN;
362 if (!crypto_is_larval(larval))
363 goto drop_larval;
364
365 ptype.attr.rta_len = sizeof(ptype);
366 ptype.attr.rta_type = CRYPTOA_TYPE;
367 ptype.data.type = type | CRYPTO_ALG_GENIV;
368 /* GENIV tells the template that we're making a default geniv. */
369 ptype.data.mask = mask | CRYPTO_ALG_GENIV;
370 tb[0] = &ptype.attr;
371
372 palg.attr.rta_len = sizeof(palg);
373 palg.attr.rta_type = CRYPTOA_ALG;
374 /* Must use the exact name to locate ourselves. */
375 memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
376 tb[1] = &palg.attr;
377
378 tb[2] = NULL;
379
380 geniv = alg->cra_aead.geniv;
381
382 tmpl = crypto_lookup_template(geniv);
383 err = -ENOENT;
384 if (!tmpl)
385 goto kill_larval;
386
387 inst = tmpl->alloc(tb);
388 err = PTR_ERR(inst);
389 if (IS_ERR(inst))
390 goto put_tmpl;
391
392 if ((err = crypto_register_instance(tmpl, inst))) {
393 tmpl->free(inst);
394 goto put_tmpl;
395 }
396
397 /* Redo the lookup to use the instance we just registered. */
398 err = -EAGAIN;
399
400 put_tmpl:
401 crypto_tmpl_put(tmpl);
402 kill_larval:
403 crypto_larval_kill(larval);
404 drop_larval:
405 crypto_mod_put(larval);
406 out:
407 crypto_mod_put(alg);
408 return err;
409 }
410
crypto_lookup_aead(const char * name,u32 type,u32 mask)411 static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
412 u32 mask)
413 {
414 struct crypto_alg *alg;
415
416 alg = crypto_alg_mod_lookup(name, type, mask);
417 if (IS_ERR(alg))
418 return alg;
419
420 if (alg->cra_type == &crypto_aead_type)
421 return alg;
422
423 if (!alg->cra_aead.ivsize)
424 return alg;
425
426 crypto_mod_put(alg);
427 alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
428 mask & ~CRYPTO_ALG_TESTED);
429 if (IS_ERR(alg))
430 return alg;
431
432 if (alg->cra_type == &crypto_aead_type) {
433 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
434 crypto_mod_put(alg);
435 alg = ERR_PTR(-ENOENT);
436 }
437 return alg;
438 }
439
440 BUG_ON(!alg->cra_aead.ivsize);
441
442 return ERR_PTR(crypto_nivaead_default(alg, type, mask));
443 }
444
crypto_grab_aead(struct crypto_aead_spawn * spawn,const char * name,u32 type,u32 mask)445 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
446 u32 type, u32 mask)
447 {
448 struct crypto_alg *alg;
449 int err;
450
451 type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
452 type |= CRYPTO_ALG_TYPE_AEAD;
453 mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
454 mask |= CRYPTO_ALG_TYPE_MASK;
455
456 alg = crypto_lookup_aead(name, type, mask);
457 if (IS_ERR(alg))
458 return PTR_ERR(alg);
459
460 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
461 crypto_mod_put(alg);
462 return err;
463 }
464 EXPORT_SYMBOL_GPL(crypto_grab_aead);
465
crypto_alloc_aead(const char * alg_name,u32 type,u32 mask)466 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
467 {
468 struct crypto_tfm *tfm;
469 int err;
470
471 type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
472 type |= CRYPTO_ALG_TYPE_AEAD;
473 mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
474 mask |= CRYPTO_ALG_TYPE_MASK;
475
476 for (;;) {
477 struct crypto_alg *alg;
478
479 alg = crypto_lookup_aead(alg_name, type, mask);
480 if (IS_ERR(alg)) {
481 err = PTR_ERR(alg);
482 goto err;
483 }
484
485 tfm = __crypto_alloc_tfm(alg, type, mask);
486 if (!IS_ERR(tfm))
487 return __crypto_aead_cast(tfm);
488
489 crypto_mod_put(alg);
490 err = PTR_ERR(tfm);
491
492 err:
493 if (err != -EAGAIN)
494 break;
495 if (signal_pending(current)) {
496 err = -EINTR;
497 break;
498 }
499 }
500
501 return ERR_PTR(err);
502 }
503 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
504
505 MODULE_LICENSE("GPL");
506 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
507