1/*
2 * AEAD: Authenticated Encryption with Associated Data
3 *
4 * This file provides API support for AEAD algorithms.
5 *
6 * Copyright (c) 2007-2015 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/geniv.h>
16#include <crypto/internal/rng.h>
17#include <crypto/null.h>
18#include <crypto/scatterwalk.h>
19#include <linux/err.h>
20#include <linux/init.h>
21#include <linux/kernel.h>
22#include <linux/module.h>
23#include <linux/rtnetlink.h>
24#include <linux/slab.h>
25#include <linux/seq_file.h>
26#include <linux/cryptouser.h>
27#include <net/netlink.h>
28
29#include "internal.h"
30
31static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
32			    unsigned int keylen)
33{
34	unsigned long alignmask = crypto_aead_alignmask(tfm);
35	int ret;
36	u8 *buffer, *alignbuffer;
37	unsigned long absize;
38
39	absize = keylen + alignmask;
40	buffer = kmalloc(absize, GFP_ATOMIC);
41	if (!buffer)
42		return -ENOMEM;
43
44	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
45	memcpy(alignbuffer, key, keylen);
46	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
47	memset(alignbuffer, 0, keylen);
48	kfree(buffer);
49	return ret;
50}
51
52int crypto_aead_setkey(struct crypto_aead *tfm,
53		       const u8 *key, unsigned int keylen)
54{
55	unsigned long alignmask = crypto_aead_alignmask(tfm);
56
57	if ((unsigned long)key & alignmask)
58		return setkey_unaligned(tfm, key, keylen);
59
60	return crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
61}
62EXPORT_SYMBOL_GPL(crypto_aead_setkey);
63
64int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
65{
66	int err;
67
68	if (authsize > crypto_aead_maxauthsize(tfm))
69		return -EINVAL;
70
71	if (crypto_aead_alg(tfm)->setauthsize) {
72		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
73		if (err)
74			return err;
75	}
76
77	tfm->authsize = authsize;
78	return 0;
79}
80EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
81
82static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
83{
84	struct crypto_aead *aead = __crypto_aead_cast(tfm);
85	struct aead_alg *alg = crypto_aead_alg(aead);
86
87	alg->exit(aead);
88}
89
90static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
91{
92	struct crypto_aead *aead = __crypto_aead_cast(tfm);
93	struct aead_alg *alg = crypto_aead_alg(aead);
94
95	aead->authsize = alg->maxauthsize;
96
97	if (alg->exit)
98		aead->base.exit = crypto_aead_exit_tfm;
99
100	if (alg->init)
101		return alg->init(aead);
102
103	return 0;
104}
105
106#ifdef CONFIG_NET
107static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
108{
109	struct crypto_report_aead raead;
110	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
111
112	strncpy(raead.type, "aead", sizeof(raead.type));
113	strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
114
115	raead.blocksize = alg->cra_blocksize;
116	raead.maxauthsize = aead->maxauthsize;
117	raead.ivsize = aead->ivsize;
118
119	if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
120		    sizeof(struct crypto_report_aead), &raead))
121		goto nla_put_failure;
122	return 0;
123
124nla_put_failure:
125	return -EMSGSIZE;
126}
127#else
128static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
129{
130	return -ENOSYS;
131}
132#endif
133
134static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
135	__attribute__ ((unused));
136static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
137{
138	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
139
140	seq_printf(m, "type         : aead\n");
141	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
142					     "yes" : "no");
143	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
144	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
145	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
146	seq_printf(m, "geniv        : <none>\n");
147}
148
149static void crypto_aead_free_instance(struct crypto_instance *inst)
150{
151	struct aead_instance *aead = aead_instance(inst);
152
153	if (!aead->free) {
154		inst->tmpl->free(inst);
155		return;
156	}
157
158	aead->free(aead);
159}
160
161static const struct crypto_type crypto_aead_type = {
162	.extsize = crypto_alg_extsize,
163	.init_tfm = crypto_aead_init_tfm,
164	.free = crypto_aead_free_instance,
165#ifdef CONFIG_PROC_FS
166	.show = crypto_aead_show,
167#endif
168	.report = crypto_aead_report,
169	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
170	.maskset = CRYPTO_ALG_TYPE_MASK,
171	.type = CRYPTO_ALG_TYPE_AEAD,
172	.tfmsize = offsetof(struct crypto_aead, base),
173};
174
175static int aead_geniv_setkey(struct crypto_aead *tfm,
176			     const u8 *key, unsigned int keylen)
177{
178	struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
179
180	return crypto_aead_setkey(ctx->child, key, keylen);
181}
182
183static int aead_geniv_setauthsize(struct crypto_aead *tfm,
184				  unsigned int authsize)
185{
186	struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
187
188	return crypto_aead_setauthsize(ctx->child, authsize);
189}
190
191struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
192				       struct rtattr **tb, u32 type, u32 mask)
193{
194	const char *name;
195	struct crypto_aead_spawn *spawn;
196	struct crypto_attr_type *algt;
197	struct aead_instance *inst;
198	struct aead_alg *alg;
199	unsigned int ivsize;
200	unsigned int maxauthsize;
201	int err;
202
203	algt = crypto_get_attr_type(tb);
204	if (IS_ERR(algt))
205		return ERR_CAST(algt);
206
207	if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
208		return ERR_PTR(-EINVAL);
209
210	name = crypto_attr_alg_name(tb[1]);
211	if (IS_ERR(name))
212		return ERR_CAST(name);
213
214	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
215	if (!inst)
216		return ERR_PTR(-ENOMEM);
217
218	spawn = aead_instance_ctx(inst);
219
220	/* Ignore async algorithms if necessary. */
221	mask |= crypto_requires_sync(algt->type, algt->mask);
222
223	crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
224	err = crypto_grab_aead(spawn, name, type, mask);
225	if (err)
226		goto err_free_inst;
227
228	alg = crypto_spawn_aead_alg(spawn);
229
230	ivsize = crypto_aead_alg_ivsize(alg);
231	maxauthsize = crypto_aead_alg_maxauthsize(alg);
232
233	err = -EINVAL;
234	if (ivsize < sizeof(u64))
235		goto err_drop_alg;
236
237	err = -ENAMETOOLONG;
238	if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
239		     "%s(%s)", tmpl->name, alg->base.cra_name) >=
240	    CRYPTO_MAX_ALG_NAME)
241		goto err_drop_alg;
242	if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
243		     "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
244	    CRYPTO_MAX_ALG_NAME)
245		goto err_drop_alg;
246
247	inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
248	inst->alg.base.cra_priority = alg->base.cra_priority;
249	inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
250	inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
251	inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
252
253	inst->alg.setkey = aead_geniv_setkey;
254	inst->alg.setauthsize = aead_geniv_setauthsize;
255
256	inst->alg.ivsize = ivsize;
257	inst->alg.maxauthsize = maxauthsize;
258
259out:
260	return inst;
261
262err_drop_alg:
263	crypto_drop_aead(spawn);
264err_free_inst:
265	kfree(inst);
266	inst = ERR_PTR(err);
267	goto out;
268}
269EXPORT_SYMBOL_GPL(aead_geniv_alloc);
270
271void aead_geniv_free(struct aead_instance *inst)
272{
273	crypto_drop_aead(aead_instance_ctx(inst));
274	kfree(inst);
275}
276EXPORT_SYMBOL_GPL(aead_geniv_free);
277
278int aead_init_geniv(struct crypto_aead *aead)
279{
280	struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
281	struct aead_instance *inst = aead_alg_instance(aead);
282	struct crypto_aead *child;
283	int err;
284
285	spin_lock_init(&ctx->lock);
286
287	err = crypto_get_default_rng();
288	if (err)
289		goto out;
290
291	err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
292				   crypto_aead_ivsize(aead));
293	crypto_put_default_rng();
294	if (err)
295		goto out;
296
297	ctx->null = crypto_get_default_null_skcipher();
298	err = PTR_ERR(ctx->null);
299	if (IS_ERR(ctx->null))
300		goto out;
301
302	child = crypto_spawn_aead(aead_instance_ctx(inst));
303	err = PTR_ERR(child);
304	if (IS_ERR(child))
305		goto drop_null;
306
307	ctx->child = child;
308	crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
309				      sizeof(struct aead_request));
310
311	err = 0;
312
313out:
314	return err;
315
316drop_null:
317	crypto_put_default_null_skcipher();
318	goto out;
319}
320EXPORT_SYMBOL_GPL(aead_init_geniv);
321
322void aead_exit_geniv(struct crypto_aead *tfm)
323{
324	struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
325
326	crypto_free_aead(ctx->child);
327	crypto_put_default_null_skcipher();
328}
329EXPORT_SYMBOL_GPL(aead_exit_geniv);
330
331int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
332		     u32 type, u32 mask)
333{
334	spawn->base.frontend = &crypto_aead_type;
335	return crypto_grab_spawn(&spawn->base, name, type, mask);
336}
337EXPORT_SYMBOL_GPL(crypto_grab_aead);
338
339struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
340{
341	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
342}
343EXPORT_SYMBOL_GPL(crypto_alloc_aead);
344
345static int aead_prepare_alg(struct aead_alg *alg)
346{
347	struct crypto_alg *base = &alg->base;
348
349	if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
350		return -EINVAL;
351
352	base->cra_type = &crypto_aead_type;
353	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
354	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
355
356	return 0;
357}
358
359int crypto_register_aead(struct aead_alg *alg)
360{
361	struct crypto_alg *base = &alg->base;
362	int err;
363
364	err = aead_prepare_alg(alg);
365	if (err)
366		return err;
367
368	return crypto_register_alg(base);
369}
370EXPORT_SYMBOL_GPL(crypto_register_aead);
371
372void crypto_unregister_aead(struct aead_alg *alg)
373{
374	crypto_unregister_alg(&alg->base);
375}
376EXPORT_SYMBOL_GPL(crypto_unregister_aead);
377
378int crypto_register_aeads(struct aead_alg *algs, int count)
379{
380	int i, ret;
381
382	for (i = 0; i < count; i++) {
383		ret = crypto_register_aead(&algs[i]);
384		if (ret)
385			goto err;
386	}
387
388	return 0;
389
390err:
391	for (--i; i >= 0; --i)
392		crypto_unregister_aead(&algs[i]);
393
394	return ret;
395}
396EXPORT_SYMBOL_GPL(crypto_register_aeads);
397
398void crypto_unregister_aeads(struct aead_alg *algs, int count)
399{
400	int i;
401
402	for (i = count - 1; i >= 0; --i)
403		crypto_unregister_aead(&algs[i]);
404}
405EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
406
407int aead_register_instance(struct crypto_template *tmpl,
408			   struct aead_instance *inst)
409{
410	int err;
411
412	err = aead_prepare_alg(&inst->alg);
413	if (err)
414		return err;
415
416	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
417}
418EXPORT_SYMBOL_GPL(aead_register_instance);
419
420MODULE_LICENSE("GPL");
421MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
422