xref: /openbmc/linux/crypto/aead.c (revision 864a0242)
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 
23 static inline struct crypto_istat_aead *aead_get_stat(struct aead_alg *alg)
24 {
25 #ifdef CONFIG_CRYPTO_STATS
26 	return &alg->stat;
27 #else
28 	return NULL;
29 #endif
30 }
31 
32 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
33 			    unsigned int keylen)
34 {
35 	unsigned long alignmask = crypto_aead_alignmask(tfm);
36 	int ret;
37 	u8 *buffer, *alignbuffer;
38 	unsigned long absize;
39 
40 	absize = keylen + alignmask;
41 	buffer = kmalloc(absize, GFP_ATOMIC);
42 	if (!buffer)
43 		return -ENOMEM;
44 
45 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
46 	memcpy(alignbuffer, key, keylen);
47 	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
48 	kfree_sensitive(buffer);
49 	return ret;
50 }
51 
52 int crypto_aead_setkey(struct crypto_aead *tfm,
53 		       const u8 *key, unsigned int keylen)
54 {
55 	unsigned long alignmask = crypto_aead_alignmask(tfm);
56 	int err;
57 
58 	if ((unsigned long)key & alignmask)
59 		err = setkey_unaligned(tfm, key, keylen);
60 	else
61 		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
62 
63 	if (unlikely(err)) {
64 		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
65 		return err;
66 	}
67 
68 	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
69 	return 0;
70 }
71 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
72 
73 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
74 {
75 	int err;
76 
77 	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
78 	    authsize > crypto_aead_maxauthsize(tfm))
79 		return -EINVAL;
80 
81 	if (crypto_aead_alg(tfm)->setauthsize) {
82 		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
83 		if (err)
84 			return err;
85 	}
86 
87 	tfm->authsize = authsize;
88 	return 0;
89 }
90 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
91 
92 static inline int crypto_aead_errstat(struct crypto_istat_aead *istat, int err)
93 {
94 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
95 		return err;
96 
97 	if (err && err != -EINPROGRESS && err != -EBUSY)
98 		atomic64_inc(&istat->err_cnt);
99 
100 	return err;
101 }
102 
103 int crypto_aead_encrypt(struct aead_request *req)
104 {
105 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
106 	struct aead_alg *alg = crypto_aead_alg(aead);
107 	struct crypto_istat_aead *istat;
108 	int ret;
109 
110 	istat = aead_get_stat(alg);
111 
112 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
113 		atomic64_inc(&istat->encrypt_cnt);
114 		atomic64_add(req->cryptlen, &istat->encrypt_tlen);
115 	}
116 
117 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
118 		ret = -ENOKEY;
119 	else
120 		ret = alg->encrypt(req);
121 
122 	return crypto_aead_errstat(istat, ret);
123 }
124 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
125 
126 int crypto_aead_decrypt(struct aead_request *req)
127 {
128 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
129 	struct aead_alg *alg = crypto_aead_alg(aead);
130 	struct crypto_istat_aead *istat;
131 	int ret;
132 
133 	istat = aead_get_stat(alg);
134 
135 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
136 		atomic64_inc(&istat->encrypt_cnt);
137 		atomic64_add(req->cryptlen, &istat->encrypt_tlen);
138 	}
139 
140 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
141 		ret = -ENOKEY;
142 	else if (req->cryptlen < crypto_aead_authsize(aead))
143 		ret = -EINVAL;
144 	else
145 		ret = alg->decrypt(req);
146 
147 	return crypto_aead_errstat(istat, ret);
148 }
149 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
150 
151 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
152 {
153 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
154 	struct aead_alg *alg = crypto_aead_alg(aead);
155 
156 	alg->exit(aead);
157 }
158 
159 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
160 {
161 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
162 	struct aead_alg *alg = crypto_aead_alg(aead);
163 
164 	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
165 
166 	aead->authsize = alg->maxauthsize;
167 
168 	if (alg->exit)
169 		aead->base.exit = crypto_aead_exit_tfm;
170 
171 	if (alg->init)
172 		return alg->init(aead);
173 
174 	return 0;
175 }
176 
177 static int __maybe_unused crypto_aead_report(
178 	struct sk_buff *skb, struct crypto_alg *alg)
179 {
180 	struct crypto_report_aead raead;
181 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
182 
183 	memset(&raead, 0, sizeof(raead));
184 
185 	strscpy(raead.type, "aead", sizeof(raead.type));
186 	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
187 
188 	raead.blocksize = alg->cra_blocksize;
189 	raead.maxauthsize = aead->maxauthsize;
190 	raead.ivsize = aead->ivsize;
191 
192 	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
193 }
194 
195 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
196 	__maybe_unused;
197 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
198 {
199 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
200 
201 	seq_printf(m, "type         : aead\n");
202 	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
203 					     "yes" : "no");
204 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
205 	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
206 	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
207 	seq_printf(m, "geniv        : <none>\n");
208 }
209 
210 static void crypto_aead_free_instance(struct crypto_instance *inst)
211 {
212 	struct aead_instance *aead = aead_instance(inst);
213 
214 	aead->free(aead);
215 }
216 
217 static int __maybe_unused crypto_aead_report_stat(
218 	struct sk_buff *skb, struct crypto_alg *alg)
219 {
220 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
221 	struct crypto_istat_aead *istat = aead_get_stat(aead);
222 	struct crypto_stat_aead raead;
223 
224 	memset(&raead, 0, sizeof(raead));
225 
226 	strscpy(raead.type, "aead", sizeof(raead.type));
227 
228 	raead.stat_encrypt_cnt = atomic64_read(&istat->encrypt_cnt);
229 	raead.stat_encrypt_tlen = atomic64_read(&istat->encrypt_tlen);
230 	raead.stat_decrypt_cnt = atomic64_read(&istat->decrypt_cnt);
231 	raead.stat_decrypt_tlen = atomic64_read(&istat->decrypt_tlen);
232 	raead.stat_err_cnt = atomic64_read(&istat->err_cnt);
233 
234 	return nla_put(skb, CRYPTOCFGA_STAT_AEAD, sizeof(raead), &raead);
235 }
236 
237 static const struct crypto_type crypto_aead_type = {
238 	.extsize = crypto_alg_extsize,
239 	.init_tfm = crypto_aead_init_tfm,
240 	.free = crypto_aead_free_instance,
241 #ifdef CONFIG_PROC_FS
242 	.show = crypto_aead_show,
243 #endif
244 #if IS_ENABLED(CONFIG_CRYPTO_USER)
245 	.report = crypto_aead_report,
246 #endif
247 #ifdef CONFIG_CRYPTO_STATS
248 	.report_stat = crypto_aead_report_stat,
249 #endif
250 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
251 	.maskset = CRYPTO_ALG_TYPE_MASK,
252 	.type = CRYPTO_ALG_TYPE_AEAD,
253 	.tfmsize = offsetof(struct crypto_aead, base),
254 };
255 
256 int crypto_grab_aead(struct crypto_aead_spawn *spawn,
257 		     struct crypto_instance *inst,
258 		     const char *name, u32 type, u32 mask)
259 {
260 	spawn->base.frontend = &crypto_aead_type;
261 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
262 }
263 EXPORT_SYMBOL_GPL(crypto_grab_aead);
264 
265 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
266 {
267 	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
268 }
269 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
270 
271 static int aead_prepare_alg(struct aead_alg *alg)
272 {
273 	struct crypto_istat_aead *istat = aead_get_stat(alg);
274 	struct crypto_alg *base = &alg->base;
275 
276 	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
277 	    PAGE_SIZE / 8)
278 		return -EINVAL;
279 
280 	if (!alg->chunksize)
281 		alg->chunksize = base->cra_blocksize;
282 
283 	base->cra_type = &crypto_aead_type;
284 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
285 	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
286 
287 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
288 		memset(istat, 0, sizeof(*istat));
289 
290 	return 0;
291 }
292 
293 int crypto_register_aead(struct aead_alg *alg)
294 {
295 	struct crypto_alg *base = &alg->base;
296 	int err;
297 
298 	err = aead_prepare_alg(alg);
299 	if (err)
300 		return err;
301 
302 	return crypto_register_alg(base);
303 }
304 EXPORT_SYMBOL_GPL(crypto_register_aead);
305 
306 void crypto_unregister_aead(struct aead_alg *alg)
307 {
308 	crypto_unregister_alg(&alg->base);
309 }
310 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
311 
312 int crypto_register_aeads(struct aead_alg *algs, int count)
313 {
314 	int i, ret;
315 
316 	for (i = 0; i < count; i++) {
317 		ret = crypto_register_aead(&algs[i]);
318 		if (ret)
319 			goto err;
320 	}
321 
322 	return 0;
323 
324 err:
325 	for (--i; i >= 0; --i)
326 		crypto_unregister_aead(&algs[i]);
327 
328 	return ret;
329 }
330 EXPORT_SYMBOL_GPL(crypto_register_aeads);
331 
332 void crypto_unregister_aeads(struct aead_alg *algs, int count)
333 {
334 	int i;
335 
336 	for (i = count - 1; i >= 0; --i)
337 		crypto_unregister_aead(&algs[i]);
338 }
339 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
340 
341 int aead_register_instance(struct crypto_template *tmpl,
342 			   struct aead_instance *inst)
343 {
344 	int err;
345 
346 	if (WARN_ON(!inst->free))
347 		return -EINVAL;
348 
349 	err = aead_prepare_alg(&inst->alg);
350 	if (err)
351 		return err;
352 
353 	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
354 }
355 EXPORT_SYMBOL_GPL(aead_register_instance);
356 
357 MODULE_LICENSE("GPL");
358 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
359