aead.c

  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 <linux/string_choices.h>
 20#include <net/netlink.h>
 21
 22#include "internal.h"
 23
 24static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
 25			    unsigned int keylen)
 26{
 27	unsigned long alignmask = crypto_aead_alignmask(tfm);
 28	int ret;
 29	u8 *buffer, *alignbuffer;
 30	unsigned long absize;
 31
 32	absize = keylen + alignmask;
 33	buffer = kmalloc(absize, GFP_ATOMIC);
 34	if (!buffer)
 35		return -ENOMEM;
 36
 37	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
 38	memcpy(alignbuffer, key, keylen);
 39	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
 40	kfree_sensitive(buffer);
 41	return ret;
 42}
 43
 44int crypto_aead_setkey(struct crypto_aead *tfm,
 45		       const u8 *key, unsigned int keylen)
 46{
 47	unsigned long alignmask = crypto_aead_alignmask(tfm);
 48	int err;
 49
 50	if ((unsigned long)key & alignmask)
 51		err = setkey_unaligned(tfm, key, keylen);
 52	else
 53		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
 54
 55	if (unlikely(err)) {
 56		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
 57		return err;
 58	}
 59
 60	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
 61	return 0;
 62}
 63EXPORT_SYMBOL_GPL(crypto_aead_setkey);
 64
 65int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
 66{
 67	int err;
 68
 69	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
 70	    authsize > crypto_aead_maxauthsize(tfm))
 71		return -EINVAL;
 72
 73	if (crypto_aead_alg(tfm)->setauthsize) {
 74		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
 75		if (err)
 76			return err;
 77	}
 78
 79	tfm->authsize = authsize;
 80	return 0;
 81}
 82EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
 83
 84int crypto_aead_encrypt(struct aead_request *req)
 85{
 86	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 87
 88	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
 89		return -ENOKEY;
 90
 91	return crypto_aead_alg(aead)->encrypt(req);
 92}
 93EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
 94
 95int crypto_aead_decrypt(struct aead_request *req)
 96{
 97	struct crypto_aead *aead = crypto_aead_reqtfm(req);
 98
 99	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
100		return -ENOKEY;
101
102	if (req->cryptlen < crypto_aead_authsize(aead))
103		return -EINVAL;
104
105	return crypto_aead_alg(aead)->decrypt(req);
106}
107EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
108
109static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
110{
111	struct crypto_aead *aead = __crypto_aead_cast(tfm);
112	struct aead_alg *alg = crypto_aead_alg(aead);
113
114	alg->exit(aead);
115}
116
117static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
118{
119	struct crypto_aead *aead = __crypto_aead_cast(tfm);
120	struct aead_alg *alg = crypto_aead_alg(aead);
121
122	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
123	crypto_aead_set_reqsize(aead, crypto_tfm_alg_reqsize(tfm));
124
125	aead->authsize = alg->maxauthsize;
126
127	if (alg->exit)
128		aead->base.exit = crypto_aead_exit_tfm;
129
130	if (alg->init)
131		return alg->init(aead);
132
133	return 0;
134}
135
136static int __maybe_unused crypto_aead_report(
137	struct sk_buff *skb, struct crypto_alg *alg)
138{
139	struct crypto_report_aead raead;
140	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
141
142	memset(&raead, 0, sizeof(raead));
143
144	strscpy(raead.type, "aead", sizeof(raead.type));
145	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
146
147	raead.blocksize = alg->cra_blocksize;
148	raead.maxauthsize = aead->maxauthsize;
149	raead.ivsize = aead->ivsize;
150
151	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
152}
153
154static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
155	__maybe_unused;
156static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
157{
158	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
159
160	seq_printf(m, "type         : aead\n");
161	seq_printf(m, "async        : %s\n",
162		   str_yes_no(alg->cra_flags & CRYPTO_ALG_ASYNC));
163	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
164	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
165	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
166	seq_printf(m, "geniv        : <none>\n");
167}
168
169static void crypto_aead_free_instance(struct crypto_instance *inst)
170{
171	struct aead_instance *aead = aead_instance(inst);
172
173	aead->free(aead);
174}
175
176static const struct crypto_type crypto_aead_type = {
177	.extsize = crypto_alg_extsize,
178	.init_tfm = crypto_aead_init_tfm,
179	.free = crypto_aead_free_instance,
180#ifdef CONFIG_PROC_FS
181	.show = crypto_aead_show,
182#endif
183#if IS_ENABLED(CONFIG_CRYPTO_USER)
184	.report = crypto_aead_report,
185#endif
186	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
187	.maskset = CRYPTO_ALG_TYPE_MASK,
188	.type = CRYPTO_ALG_TYPE_AEAD,
189	.tfmsize = offsetof(struct crypto_aead, base),
190	.algsize = offsetof(struct aead_alg, base),
191};
192
193int crypto_grab_aead(struct crypto_aead_spawn *spawn,
194		     struct crypto_instance *inst,
195		     const char *name, u32 type, u32 mask)
196{
197	spawn->base.frontend = &crypto_aead_type;
198	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
199}
200EXPORT_SYMBOL_GPL(crypto_grab_aead);
201
202struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
203{
204	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
205}
206EXPORT_SYMBOL_GPL(crypto_alloc_aead);
207
208struct crypto_sync_aead *crypto_alloc_sync_aead(const char *alg_name, u32 type, u32 mask)
209{
210	struct crypto_aead *tfm;
211
212	/* Only sync algorithms are allowed. */
213	mask |= CRYPTO_ALG_ASYNC;
214	type &= ~(CRYPTO_ALG_ASYNC);
215
216	tfm = crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
217
218	if (!IS_ERR(tfm) && WARN_ON(crypto_aead_reqsize(tfm) > MAX_SYNC_AEAD_REQSIZE)) {
219		crypto_free_aead(tfm);
220		return ERR_PTR(-EINVAL);
221	}
222
223	return (struct crypto_sync_aead *)tfm;
224}
225EXPORT_SYMBOL_GPL(crypto_alloc_sync_aead);
226
227int crypto_has_aead(const char *alg_name, u32 type, u32 mask)
228{
229	return crypto_type_has_alg(alg_name, &crypto_aead_type, type, mask);
230}
231EXPORT_SYMBOL_GPL(crypto_has_aead);
232
233static int aead_prepare_alg(struct aead_alg *alg)
234{
235	struct crypto_alg *base = &alg->base;
236
237	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
238	    PAGE_SIZE / 8)
239		return -EINVAL;
240
241	if (!alg->chunksize)
242		alg->chunksize = base->cra_blocksize;
243
244	base->cra_type = &crypto_aead_type;
245	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
246	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
247
248	return 0;
249}
250
251int crypto_register_aead(struct aead_alg *alg)
252{
253	struct crypto_alg *base = &alg->base;
254	int err;
255
256	err = aead_prepare_alg(alg);
257	if (err)
258		return err;
259
260	return crypto_register_alg(base);
261}
262EXPORT_SYMBOL_GPL(crypto_register_aead);
263
264void crypto_unregister_aead(struct aead_alg *alg)
265{
266	crypto_unregister_alg(&alg->base);
267}
268EXPORT_SYMBOL_GPL(crypto_unregister_aead);
269
270int crypto_register_aeads(struct aead_alg *algs, int count)
271{
272	int i, ret;
273
274	for (i = 0; i < count; i++) {
275		ret = crypto_register_aead(&algs[i]);
276		if (ret)
277			goto err;
278	}
279
280	return 0;
281
282err:
283	for (--i; i >= 0; --i)
284		crypto_unregister_aead(&algs[i]);
285
286	return ret;
287}
288EXPORT_SYMBOL_GPL(crypto_register_aeads);
289
290void crypto_unregister_aeads(struct aead_alg *algs, int count)
291{
292	int i;
293
294	for (i = count - 1; i >= 0; --i)
295		crypto_unregister_aead(&algs[i]);
296}
297EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
298
299int aead_register_instance(struct crypto_template *tmpl,
300			   struct aead_instance *inst)
301{
302	int err;
303
304	if (WARN_ON(!inst->free))
305		return -EINVAL;
306
307	err = aead_prepare_alg(&inst->alg);
308	if (err)
309		return err;
310
311	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
312}
313EXPORT_SYMBOL_GPL(aead_register_instance);
314
315MODULE_LICENSE("GPL");
316MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");