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/cryptouser.h>
12#include <linux/errno.h>
13#include <linux/init.h>
14#include <linux/kernel.h>
15#include <linux/module.h>
16#include <linux/slab.h>
17#include <linux/seq_file.h>
18#include <linux/string.h>
19#include <net/netlink.h>
20
21#include "internal.h"
22
23static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
24			    unsigned int keylen)
25{
26	unsigned long alignmask = crypto_aead_alignmask(tfm);
27	int ret;
28	u8 *buffer, *alignbuffer;
29	unsigned long absize;
30
31	absize = keylen + alignmask;
32	buffer = kmalloc(absize, GFP_ATOMIC);
33	if (!buffer)
34		return -ENOMEM;
35
36	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
37	memcpy(alignbuffer, key, keylen);
38	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
39	kfree_sensitive(buffer);
40	return ret;
41}
42
43int crypto_aead_setkey(struct crypto_aead *tfm,
44		       const u8 *key, unsigned int keylen)
45{
46	unsigned long alignmask = crypto_aead_alignmask(tfm);
47	int err;
48
49	if ((unsigned long)key & alignmask)
50		err = setkey_unaligned(tfm, key, keylen);
51	else
52		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
53
54	if (unlikely(err)) {
55		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
56		return err;
57	}
58
59	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
60	return 0;
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	    authsize > crypto_aead_maxauthsize(tfm))
70		return -EINVAL;
71
72	if (crypto_aead_alg(tfm)->setauthsize) {
73		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
74		if (err)
75			return err;
76	}
77
78	tfm->authsize = authsize;
79	return 0;
80}
81EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
82
83int crypto_aead_encrypt(struct aead_request *req)
84{
85	struct crypto_aead *aead = crypto_aead_reqtfm(req);
86
87	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
88		return -ENOKEY;
89
90	return crypto_aead_alg(aead)->encrypt(req);
91}
92EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
93
94int crypto_aead_decrypt(struct aead_request *req)
95{
96	struct crypto_aead *aead = crypto_aead_reqtfm(req);
97
98	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
99		return -ENOKEY;
100
101	if (req->cryptlen < crypto_aead_authsize(aead))
102		return -EINVAL;
103
104	return crypto_aead_alg(aead)->decrypt(req);
105}
106EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
107
108static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
109{
110	struct crypto_aead *aead = __crypto_aead_cast(tfm);
111	struct aead_alg *alg = crypto_aead_alg(aead);
112
113	alg->exit(aead);
114}
115
116static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
117{
118	struct crypto_aead *aead = __crypto_aead_cast(tfm);
119	struct aead_alg *alg = crypto_aead_alg(aead);
120
121	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
122
123	aead->authsize = alg->maxauthsize;
124
125	if (alg->exit)
126		aead->base.exit = crypto_aead_exit_tfm;
127
128	if (alg->init)
129		return alg->init(aead);
130
131	return 0;
132}
133
134static int __maybe_unused crypto_aead_report(
135	struct sk_buff *skb, struct crypto_alg *alg)
136{
137	struct crypto_report_aead raead;
138	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
139
140	memset(&raead, 0, sizeof(raead));
141
142	strscpy(raead.type, "aead", sizeof(raead.type));
143	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
144
145	raead.blocksize = alg->cra_blocksize;
146	raead.maxauthsize = aead->maxauthsize;
147	raead.ivsize = aead->ivsize;
148
149	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
150}
151
152static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
153	__maybe_unused;
154static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
155{
156	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
157
158	seq_printf(m, "type         : aead\n");
159	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
160					     "yes" : "no");
161	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
162	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
163	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
164	seq_printf(m, "geniv        : <none>\n");
165}
166
167static void crypto_aead_free_instance(struct crypto_instance *inst)
168{
169	struct aead_instance *aead = aead_instance(inst);
170
171	aead->free(aead);
172}
173
174static const struct crypto_type crypto_aead_type = {
175	.extsize = crypto_alg_extsize,
176	.init_tfm = crypto_aead_init_tfm,
177	.free = crypto_aead_free_instance,
178#ifdef CONFIG_PROC_FS
179	.show = crypto_aead_show,
180#endif
181#if IS_ENABLED(CONFIG_CRYPTO_USER)
182	.report = crypto_aead_report,
183#endif
184	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
185	.maskset = CRYPTO_ALG_TYPE_MASK,
186	.type = CRYPTO_ALG_TYPE_AEAD,
187	.tfmsize = offsetof(struct crypto_aead, base),
188};
189
190int crypto_grab_aead(struct crypto_aead_spawn *spawn,
191		     struct crypto_instance *inst,
192		     const char *name, u32 type, u32 mask)
193{
194	spawn->base.frontend = &crypto_aead_type;
195	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
196}
197EXPORT_SYMBOL_GPL(crypto_grab_aead);
198
199struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
200{
201	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
202}
203EXPORT_SYMBOL_GPL(crypto_alloc_aead);
204
205int crypto_has_aead(const char *alg_name, u32 type, u32 mask)
206{
207	return crypto_type_has_alg(alg_name, &crypto_aead_type, type, mask);
208}
209EXPORT_SYMBOL_GPL(crypto_has_aead);
210
211static int aead_prepare_alg(struct aead_alg *alg)
212{
213	struct crypto_alg *base = &alg->base;
214
215	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
216	    PAGE_SIZE / 8)
217		return -EINVAL;
218
219	if (!alg->chunksize)
220		alg->chunksize = base->cra_blocksize;
221
222	base->cra_type = &crypto_aead_type;
223	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
224	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
225
226	return 0;
227}
228
229int crypto_register_aead(struct aead_alg *alg)
230{
231	struct crypto_alg *base = &alg->base;
232	int err;
233
234	err = aead_prepare_alg(alg);
235	if (err)
236		return err;
237
238	return crypto_register_alg(base);
239}
240EXPORT_SYMBOL_GPL(crypto_register_aead);
241
242void crypto_unregister_aead(struct aead_alg *alg)
243{
244	crypto_unregister_alg(&alg->base);
245}
246EXPORT_SYMBOL_GPL(crypto_unregister_aead);
247
248int crypto_register_aeads(struct aead_alg *algs, int count)
249{
250	int i, ret;
251
252	for (i = 0; i < count; i++) {
253		ret = crypto_register_aead(&algs[i]);
254		if (ret)
255			goto err;
256	}
257
258	return 0;
259
260err:
261	for (--i; i >= 0; --i)
262		crypto_unregister_aead(&algs[i]);
263
264	return ret;
265}
266EXPORT_SYMBOL_GPL(crypto_register_aeads);
267
268void crypto_unregister_aeads(struct aead_alg *algs, int count)
269{
270	int i;
271
272	for (i = count - 1; i >= 0; --i)
273		crypto_unregister_aead(&algs[i]);
274}
275EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
276
277int aead_register_instance(struct crypto_template *tmpl,
278			   struct aead_instance *inst)
279{
280	int err;
281
282	if (WARN_ON(!inst->free))
283		return -EINVAL;
284
285	err = aead_prepare_alg(&inst->alg);
286	if (err)
287		return err;
288
289	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
290}
291EXPORT_SYMBOL_GPL(aead_register_instance);
292
293MODULE_LICENSE("GPL");
294MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
295