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
27static 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
49static 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
60int 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}
78EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
79
80static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
81					u32 mask)
82{
83	return alg->cra_ctxsize;
84}
85
86static int no_givcrypt(struct aead_givcrypt_request *req)
87{
88	return -ENOSYS;
89}
90
91static 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
112static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
113	__attribute__ ((unused));
114static 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
127const 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};
134EXPORT_SYMBOL_GPL(crypto_aead_type);
135
136static int aead_null_givencrypt(struct aead_givcrypt_request *req)
137{
138	return crypto_aead_encrypt(&req->areq);
139}
140
141static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
142{
143	return crypto_aead_decrypt(&req->areq);
144}
145
146static 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
168static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
169	__attribute__ ((unused));
170static 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
183const 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};
190EXPORT_SYMBOL_GPL(crypto_nivaead_type);
191
192static 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
211struct 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
296out:
297	return inst;
298
299err_drop_alg:
300	crypto_drop_aead(spawn);
301err_free_inst:
302	kfree(inst);
303	inst = ERR_PTR(err);
304	goto out;
305}
306EXPORT_SYMBOL_GPL(aead_geniv_alloc);
307
308void aead_geniv_free(struct crypto_instance *inst)
309{
310	crypto_drop_aead(crypto_instance_ctx(inst));
311	kfree(inst);
312}
313EXPORT_SYMBOL_GPL(aead_geniv_free);
314
315int 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}
329EXPORT_SYMBOL_GPL(aead_geniv_init);
330
331void aead_geniv_exit(struct crypto_tfm *tfm)
332{
333	crypto_free_aead(tfm->crt_aead.base);
334}
335EXPORT_SYMBOL_GPL(aead_geniv_exit);
336
337static 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
400put_tmpl:
401	crypto_tmpl_put(tmpl);
402kill_larval:
403	crypto_larval_kill(larval);
404drop_larval:
405	crypto_mod_put(larval);
406out:
407	crypto_mod_put(alg);
408	return err;
409}
410
411static 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
445int 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}
464EXPORT_SYMBOL_GPL(crypto_grab_aead);
465
466struct 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
492err:
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}
503EXPORT_SYMBOL_GPL(crypto_alloc_aead);
504
505MODULE_LICENSE("GPL");
506MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
507