xref: /openbmc/linux/crypto/aead.c (revision 7c2435ef)
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 	memset(alignbuffer, 0, keylen);
49 	kfree(buffer);
50 	return ret;
51 }
52 
53 int crypto_aead_setkey(struct crypto_aead *tfm,
54 		       const u8 *key, unsigned int keylen)
55 {
56 	unsigned long alignmask = crypto_aead_alignmask(tfm);
57 	int err;
58 
59 	if ((unsigned long)key & alignmask)
60 		err = setkey_unaligned(tfm, key, keylen);
61 	else
62 		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
63 
64 	if (unlikely(err)) {
65 		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
66 		return err;
67 	}
68 
69 	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
70 	return 0;
71 }
72 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
73 
74 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
75 {
76 	int err;
77 
78 	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
79 	    authsize > crypto_aead_maxauthsize(tfm))
80 		return -EINVAL;
81 
82 	if (crypto_aead_alg(tfm)->setauthsize) {
83 		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
84 		if (err)
85 			return err;
86 	}
87 
88 	tfm->authsize = authsize;
89 	return 0;
90 }
91 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
92 
93 static inline int crypto_aead_errstat(struct crypto_istat_aead *istat, int err)
94 {
95 	if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
96 		return err;
97 
98 	if (err && err != -EINPROGRESS && err != -EBUSY)
99 		atomic64_inc(&istat->err_cnt);
100 
101 	return err;
102 }
103 
104 int crypto_aead_encrypt(struct aead_request *req)
105 {
106 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
107 	struct aead_alg *alg = crypto_aead_alg(aead);
108 	struct crypto_istat_aead *istat;
109 	int ret;
110 
111 	istat = aead_get_stat(alg);
112 
113 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
114 		atomic64_inc(&istat->encrypt_cnt);
115 		atomic64_add(req->cryptlen, &istat->encrypt_tlen);
116 	}
117 
118 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
119 		ret = -ENOKEY;
120 	else
121 		ret = alg->encrypt(req);
122 
123 	return crypto_aead_errstat(istat, ret);
124 }
125 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
126 
127 int crypto_aead_decrypt(struct aead_request *req)
128 {
129 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
130 	struct aead_alg *alg = crypto_aead_alg(aead);
131 	struct crypto_istat_aead *istat;
132 	int ret;
133 
134 	istat = aead_get_stat(alg);
135 
136 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
137 		atomic64_inc(&istat->encrypt_cnt);
138 		atomic64_add(req->cryptlen, &istat->encrypt_tlen);
139 	}
140 
141 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
142 		ret = -ENOKEY;
143 	else if (req->cryptlen < crypto_aead_authsize(aead))
144 		ret = -EINVAL;
145 	else
146 		ret = alg->decrypt(req);
147 
148 	return crypto_aead_errstat(istat, ret);
149 }
150 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
151 
152 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
153 {
154 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
155 	struct aead_alg *alg = crypto_aead_alg(aead);
156 
157 	alg->exit(aead);
158 }
159 
160 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
161 {
162 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
163 	struct aead_alg *alg = crypto_aead_alg(aead);
164 
165 	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
166 
167 	aead->authsize = alg->maxauthsize;
168 
169 	if (alg->exit)
170 		aead->base.exit = crypto_aead_exit_tfm;
171 
172 	if (alg->init)
173 		return alg->init(aead);
174 
175 	return 0;
176 }
177 
178 static int __maybe_unused crypto_aead_report(
179 	struct sk_buff *skb, struct crypto_alg *alg)
180 {
181 	struct crypto_report_aead raead;
182 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
183 
184 	memset(&raead, 0, sizeof(raead));
185 
186 	strscpy(raead.type, "aead", sizeof(raead.type));
187 	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
188 
189 	raead.blocksize = alg->cra_blocksize;
190 	raead.maxauthsize = aead->maxauthsize;
191 	raead.ivsize = aead->ivsize;
192 
193 	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
194 }
195 
196 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
197 	__maybe_unused;
198 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
199 {
200 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
201 
202 	seq_printf(m, "type         : aead\n");
203 	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
204 					     "yes" : "no");
205 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
206 	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
207 	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
208 	seq_printf(m, "geniv        : <none>\n");
209 }
210 
211 static void crypto_aead_free_instance(struct crypto_instance *inst)
212 {
213 	struct aead_instance *aead = aead_instance(inst);
214 
215 	aead->free(aead);
216 }
217 
218 static int __maybe_unused crypto_aead_report_stat(
219 	struct sk_buff *skb, struct crypto_alg *alg)
220 {
221 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
222 	struct crypto_istat_aead *istat = aead_get_stat(aead);
223 	struct crypto_stat_aead raead;
224 
225 	memset(&raead, 0, sizeof(raead));
226 
227 	strscpy(raead.type, "aead", sizeof(raead.type));
228 
229 	raead.stat_encrypt_cnt = atomic64_read(&istat->encrypt_cnt);
230 	raead.stat_encrypt_tlen = atomic64_read(&istat->encrypt_tlen);
231 	raead.stat_decrypt_cnt = atomic64_read(&istat->decrypt_cnt);
232 	raead.stat_decrypt_tlen = atomic64_read(&istat->decrypt_tlen);
233 	raead.stat_err_cnt = atomic64_read(&istat->err_cnt);
234 
235 	return nla_put(skb, CRYPTOCFGA_STAT_AEAD, sizeof(raead), &raead);
236 }
237 
238 static const struct crypto_type crypto_aead_type = {
239 	.extsize = crypto_alg_extsize,
240 	.init_tfm = crypto_aead_init_tfm,
241 	.free = crypto_aead_free_instance,
242 #ifdef CONFIG_PROC_FS
243 	.show = crypto_aead_show,
244 #endif
245 #if IS_ENABLED(CONFIG_CRYPTO_USER)
246 	.report = crypto_aead_report,
247 #endif
248 #ifdef CONFIG_CRYPTO_STATS
249 	.report_stat = crypto_aead_report_stat,
250 #endif
251 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
252 	.maskset = CRYPTO_ALG_TYPE_MASK,
253 	.type = CRYPTO_ALG_TYPE_AEAD,
254 	.tfmsize = offsetof(struct crypto_aead, base),
255 };
256 
257 int crypto_grab_aead(struct crypto_aead_spawn *spawn,
258 		     struct crypto_instance *inst,
259 		     const char *name, u32 type, u32 mask)
260 {
261 	spawn->base.frontend = &crypto_aead_type;
262 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
263 }
264 EXPORT_SYMBOL_GPL(crypto_grab_aead);
265 
266 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
267 {
268 	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
269 }
270 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
271 
272 static int aead_prepare_alg(struct aead_alg *alg)
273 {
274 	struct crypto_istat_aead *istat = aead_get_stat(alg);
275 	struct crypto_alg *base = &alg->base;
276 
277 	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
278 	    PAGE_SIZE / 8)
279 		return -EINVAL;
280 
281 	if (!alg->chunksize)
282 		alg->chunksize = base->cra_blocksize;
283 
284 	base->cra_type = &crypto_aead_type;
285 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
286 	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
287 
288 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
289 		memset(istat, 0, sizeof(*istat));
290 
291 	return 0;
292 }
293 
294 int crypto_register_aead(struct aead_alg *alg)
295 {
296 	struct crypto_alg *base = &alg->base;
297 	int err;
298 
299 	err = aead_prepare_alg(alg);
300 	if (err)
301 		return err;
302 
303 	return crypto_register_alg(base);
304 }
305 EXPORT_SYMBOL_GPL(crypto_register_aead);
306 
307 void crypto_unregister_aead(struct aead_alg *alg)
308 {
309 	crypto_unregister_alg(&alg->base);
310 }
311 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
312 
313 int crypto_register_aeads(struct aead_alg *algs, int count)
314 {
315 	int i, ret;
316 
317 	for (i = 0; i < count; i++) {
318 		ret = crypto_register_aead(&algs[i]);
319 		if (ret)
320 			goto err;
321 	}
322 
323 	return 0;
324 
325 err:
326 	for (--i; i >= 0; --i)
327 		crypto_unregister_aead(&algs[i]);
328 
329 	return ret;
330 }
331 EXPORT_SYMBOL_GPL(crypto_register_aeads);
332 
333 void crypto_unregister_aeads(struct aead_alg *algs, int count)
334 {
335 	int i;
336 
337 	for (i = count - 1; i >= 0; --i)
338 		crypto_unregister_aead(&algs[i]);
339 }
340 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
341 
342 int aead_register_instance(struct crypto_template *tmpl,
343 			   struct aead_instance *inst)
344 {
345 	int err;
346 
347 	if (WARN_ON(!inst->free))
348 		return -EINVAL;
349 
350 	err = aead_prepare_alg(&inst->alg);
351 	if (err)
352 		return err;
353 
354 	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
355 }
356 EXPORT_SYMBOL_GPL(aead_register_instance);
357 
358 MODULE_LICENSE("GPL");
359 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
360