xref: /kernel/linux/linux-5.10/crypto/aead.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * AEAD: Authenticated Encryption with Associated Data
4 *
5 * This file provides API support for AEAD algorithms.
6 *
7 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
8 */
9
10#include <crypto/internal/aead.h>
11#include <linux/errno.h>
12#include <linux/init.h>
13#include <linux/kernel.h>
14#include <linux/module.h>
15#include <linux/slab.h>
16#include <linux/seq_file.h>
17#include <linux/cryptouser.h>
18#include <net/netlink.h>
19
20#include "internal.h"
21
22static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
23			    unsigned int keylen)
24{
25	unsigned long alignmask = crypto_aead_alignmask(tfm);
26	int ret;
27	u8 *buffer, *alignbuffer;
28	unsigned long absize;
29
30	absize = keylen + alignmask;
31	buffer = kmalloc(absize, GFP_ATOMIC);
32	if (!buffer)
33		return -ENOMEM;
34
35	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
36	memcpy(alignbuffer, key, keylen);
37	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
38	kfree_sensitive(buffer);
39	return ret;
40}
41
42int crypto_aead_setkey(struct crypto_aead *tfm,
43		       const u8 *key, unsigned int keylen)
44{
45	unsigned long alignmask = crypto_aead_alignmask(tfm);
46	int err;
47
48	if ((unsigned long)key & alignmask)
49		err = setkey_unaligned(tfm, key, keylen);
50	else
51		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
52
53	if (unlikely(err)) {
54		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
55		return err;
56	}
57
58	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
59	return 0;
60}
61EXPORT_SYMBOL_GPL(crypto_aead_setkey);
62
63int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
64{
65	int err;
66
67	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
68	    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
82int crypto_aead_encrypt(struct aead_request *req)
83{
84	struct crypto_aead *aead = crypto_aead_reqtfm(req);
85	struct crypto_alg *alg = aead->base.__crt_alg;
86	unsigned int cryptlen = req->cryptlen;
87	int ret;
88
89	crypto_stats_get(alg);
90	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
91		ret = -ENOKEY;
92	else
93		ret = crypto_aead_alg(aead)->encrypt(req);
94	crypto_stats_aead_encrypt(cryptlen, alg, ret);
95	return ret;
96}
97EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
98
99int crypto_aead_decrypt(struct aead_request *req)
100{
101	struct crypto_aead *aead = crypto_aead_reqtfm(req);
102	struct crypto_alg *alg = aead->base.__crt_alg;
103	unsigned int cryptlen = req->cryptlen;
104	int ret;
105
106	crypto_stats_get(alg);
107	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
108		ret = -ENOKEY;
109	else if (req->cryptlen < crypto_aead_authsize(aead))
110		ret = -EINVAL;
111	else
112		ret = crypto_aead_alg(aead)->decrypt(req);
113	crypto_stats_aead_decrypt(cryptlen, alg, ret);
114	return ret;
115}
116EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
117
118static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
119{
120	struct crypto_aead *aead = __crypto_aead_cast(tfm);
121	struct aead_alg *alg = crypto_aead_alg(aead);
122
123	alg->exit(aead);
124}
125
126static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
127{
128	struct crypto_aead *aead = __crypto_aead_cast(tfm);
129	struct aead_alg *alg = crypto_aead_alg(aead);
130
131	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
132
133	aead->authsize = alg->maxauthsize;
134
135	if (alg->exit)
136		aead->base.exit = crypto_aead_exit_tfm;
137
138	if (alg->init)
139		return alg->init(aead);
140
141	return 0;
142}
143
144#ifdef CONFIG_NET
145static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
146{
147	struct crypto_report_aead raead;
148	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
149
150	memset(&raead, 0, sizeof(raead));
151
152	strscpy(raead.type, "aead", sizeof(raead.type));
153	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
154
155	raead.blocksize = alg->cra_blocksize;
156	raead.maxauthsize = aead->maxauthsize;
157	raead.ivsize = aead->ivsize;
158
159	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
160}
161#else
162static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
163{
164	return -ENOSYS;
165}
166#endif
167
168static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
169	__maybe_unused;
170static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
171{
172	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
173
174	seq_printf(m, "type         : aead\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        : <none>\n");
181}
182
183static void crypto_aead_free_instance(struct crypto_instance *inst)
184{
185	struct aead_instance *aead = aead_instance(inst);
186
187	aead->free(aead);
188}
189
190static const struct crypto_type crypto_aead_type = {
191	.extsize = crypto_alg_extsize,
192	.init_tfm = crypto_aead_init_tfm,
193	.free = crypto_aead_free_instance,
194#ifdef CONFIG_PROC_FS
195	.show = crypto_aead_show,
196#endif
197	.report = crypto_aead_report,
198	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
199	.maskset = CRYPTO_ALG_TYPE_MASK,
200	.type = CRYPTO_ALG_TYPE_AEAD,
201	.tfmsize = offsetof(struct crypto_aead, base),
202};
203
204int crypto_grab_aead(struct crypto_aead_spawn *spawn,
205		     struct crypto_instance *inst,
206		     const char *name, u32 type, u32 mask)
207{
208	spawn->base.frontend = &crypto_aead_type;
209	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
210}
211EXPORT_SYMBOL_GPL(crypto_grab_aead);
212
213struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
214{
215	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
216}
217EXPORT_SYMBOL_GPL(crypto_alloc_aead);
218
219static int aead_prepare_alg(struct aead_alg *alg)
220{
221	struct crypto_alg *base = &alg->base;
222
223	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
224	    PAGE_SIZE / 8)
225		return -EINVAL;
226
227	if (!alg->chunksize)
228		alg->chunksize = base->cra_blocksize;
229
230	base->cra_type = &crypto_aead_type;
231	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
232	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
233
234	return 0;
235}
236
237int crypto_register_aead(struct aead_alg *alg)
238{
239	struct crypto_alg *base = &alg->base;
240	int err;
241
242	err = aead_prepare_alg(alg);
243	if (err)
244		return err;
245
246	return crypto_register_alg(base);
247}
248EXPORT_SYMBOL_GPL(crypto_register_aead);
249
250void crypto_unregister_aead(struct aead_alg *alg)
251{
252	crypto_unregister_alg(&alg->base);
253}
254EXPORT_SYMBOL_GPL(crypto_unregister_aead);
255
256int crypto_register_aeads(struct aead_alg *algs, int count)
257{
258	int i, ret;
259
260	for (i = 0; i < count; i++) {
261		ret = crypto_register_aead(&algs[i]);
262		if (ret)
263			goto err;
264	}
265
266	return 0;
267
268err:
269	for (--i; i >= 0; --i)
270		crypto_unregister_aead(&algs[i]);
271
272	return ret;
273}
274EXPORT_SYMBOL_GPL(crypto_register_aeads);
275
276void crypto_unregister_aeads(struct aead_alg *algs, int count)
277{
278	int i;
279
280	for (i = count - 1; i >= 0; --i)
281		crypto_unregister_aead(&algs[i]);
282}
283EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
284
285int aead_register_instance(struct crypto_template *tmpl,
286			   struct aead_instance *inst)
287{
288	int err;
289
290	if (WARN_ON(!inst->free))
291		return -EINVAL;
292
293	err = aead_prepare_alg(&inst->alg);
294	if (err)
295		return err;
296
297	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
298}
299EXPORT_SYMBOL_GPL(aead_register_instance);
300
301MODULE_LICENSE("GPL");
302MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
303