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 
setkey_unaligned(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)22 static 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 	memset(alignbuffer, 0, keylen);
39 	kfree(buffer);
40 	return ret;
41 }
42 
crypto_aead_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)43 int 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 }
62 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
63 
crypto_aead_setauthsize(struct crypto_aead * tfm,unsigned int authsize)64 int 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 }
81 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
82 
crypto_aead_encrypt(struct aead_request * req)83 int crypto_aead_encrypt(struct aead_request *req)
84 {
85 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
86 	struct crypto_alg *alg = aead->base.__crt_alg;
87 	unsigned int cryptlen = req->cryptlen;
88 	int ret;
89 
90 	crypto_stats_get(alg);
91 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
92 		ret = -ENOKEY;
93 	else
94 		ret = crypto_aead_alg(aead)->encrypt(req);
95 	crypto_stats_aead_encrypt(cryptlen, alg, ret);
96 	return ret;
97 }
98 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
99 
crypto_aead_decrypt(struct aead_request * req)100 int crypto_aead_decrypt(struct aead_request *req)
101 {
102 	struct crypto_aead *aead = crypto_aead_reqtfm(req);
103 	struct crypto_alg *alg = aead->base.__crt_alg;
104 	unsigned int cryptlen = req->cryptlen;
105 	int ret;
106 
107 	crypto_stats_get(alg);
108 	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
109 		ret = -ENOKEY;
110 	else if (req->cryptlen < crypto_aead_authsize(aead))
111 		ret = -EINVAL;
112 	else
113 		ret = crypto_aead_alg(aead)->decrypt(req);
114 	crypto_stats_aead_decrypt(cryptlen, alg, ret);
115 	return ret;
116 }
117 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
118 
crypto_aead_exit_tfm(struct crypto_tfm * tfm)119 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
120 {
121 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
122 	struct aead_alg *alg = crypto_aead_alg(aead);
123 
124 	alg->exit(aead);
125 }
126 
crypto_aead_init_tfm(struct crypto_tfm * tfm)127 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
128 {
129 	struct crypto_aead *aead = __crypto_aead_cast(tfm);
130 	struct aead_alg *alg = crypto_aead_alg(aead);
131 
132 	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
133 
134 	aead->authsize = alg->maxauthsize;
135 
136 	if (alg->exit)
137 		aead->base.exit = crypto_aead_exit_tfm;
138 
139 	if (alg->init)
140 		return alg->init(aead);
141 
142 	return 0;
143 }
144 
145 #ifdef CONFIG_NET
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)146 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
147 {
148 	struct crypto_report_aead raead;
149 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
150 
151 	memset(&raead, 0, sizeof(raead));
152 
153 	strscpy(raead.type, "aead", sizeof(raead.type));
154 	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
155 
156 	raead.blocksize = alg->cra_blocksize;
157 	raead.maxauthsize = aead->maxauthsize;
158 	raead.ivsize = aead->ivsize;
159 
160 	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
161 }
162 #else
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)163 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
164 {
165 	return -ENOSYS;
166 }
167 #endif
168 
169 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
170 	__maybe_unused;
crypto_aead_show(struct seq_file * m,struct crypto_alg * alg)171 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
172 {
173 	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
174 
175 	seq_printf(m, "type         : aead\n");
176 	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
177 					     "yes" : "no");
178 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
179 	seq_printf(m, "ivsize       : %u\n", aead->ivsize);
180 	seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
181 	seq_printf(m, "geniv        : <none>\n");
182 }
183 
crypto_aead_free_instance(struct crypto_instance * inst)184 static void crypto_aead_free_instance(struct crypto_instance *inst)
185 {
186 	struct aead_instance *aead = aead_instance(inst);
187 
188 	aead->free(aead);
189 }
190 
191 static const struct crypto_type crypto_aead_type = {
192 	.extsize = crypto_alg_extsize,
193 	.init_tfm = crypto_aead_init_tfm,
194 	.free = crypto_aead_free_instance,
195 #ifdef CONFIG_PROC_FS
196 	.show = crypto_aead_show,
197 #endif
198 	.report = crypto_aead_report,
199 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
200 	.maskset = CRYPTO_ALG_TYPE_MASK,
201 	.type = CRYPTO_ALG_TYPE_AEAD,
202 	.tfmsize = offsetof(struct crypto_aead, base),
203 };
204 
crypto_grab_aead(struct crypto_aead_spawn * spawn,struct crypto_instance * inst,const char * name,u32 type,u32 mask)205 int crypto_grab_aead(struct crypto_aead_spawn *spawn,
206 		     struct crypto_instance *inst,
207 		     const char *name, u32 type, u32 mask)
208 {
209 	spawn->base.frontend = &crypto_aead_type;
210 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
211 }
212 EXPORT_SYMBOL_GPL(crypto_grab_aead);
213 
crypto_alloc_aead(const char * alg_name,u32 type,u32 mask)214 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
215 {
216 	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
217 }
218 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
219 
aead_prepare_alg(struct aead_alg * alg)220 static int aead_prepare_alg(struct aead_alg *alg)
221 {
222 	struct crypto_alg *base = &alg->base;
223 
224 	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
225 	    PAGE_SIZE / 8)
226 		return -EINVAL;
227 
228 	if (!alg->chunksize)
229 		alg->chunksize = base->cra_blocksize;
230 
231 	base->cra_type = &crypto_aead_type;
232 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
233 	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
234 
235 	return 0;
236 }
237 
crypto_register_aead(struct aead_alg * alg)238 int crypto_register_aead(struct aead_alg *alg)
239 {
240 	struct crypto_alg *base = &alg->base;
241 	int err;
242 
243 	err = aead_prepare_alg(alg);
244 	if (err)
245 		return err;
246 
247 	return crypto_register_alg(base);
248 }
249 EXPORT_SYMBOL_GPL(crypto_register_aead);
250 
crypto_unregister_aead(struct aead_alg * alg)251 void crypto_unregister_aead(struct aead_alg *alg)
252 {
253 	crypto_unregister_alg(&alg->base);
254 }
255 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
256 
crypto_register_aeads(struct aead_alg * algs,int count)257 int crypto_register_aeads(struct aead_alg *algs, int count)
258 {
259 	int i, ret;
260 
261 	for (i = 0; i < count; i++) {
262 		ret = crypto_register_aead(&algs[i]);
263 		if (ret)
264 			goto err;
265 	}
266 
267 	return 0;
268 
269 err:
270 	for (--i; i >= 0; --i)
271 		crypto_unregister_aead(&algs[i]);
272 
273 	return ret;
274 }
275 EXPORT_SYMBOL_GPL(crypto_register_aeads);
276 
crypto_unregister_aeads(struct aead_alg * algs,int count)277 void crypto_unregister_aeads(struct aead_alg *algs, int count)
278 {
279 	int i;
280 
281 	for (i = count - 1; i >= 0; --i)
282 		crypto_unregister_aead(&algs[i]);
283 }
284 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
285 
aead_register_instance(struct crypto_template * tmpl,struct aead_instance * inst)286 int aead_register_instance(struct crypto_template *tmpl,
287 			   struct aead_instance *inst)
288 {
289 	int err;
290 
291 	if (WARN_ON(!inst->free))
292 		return -EINVAL;
293 
294 	err = aead_prepare_alg(&inst->alg);
295 	if (err)
296 		return err;
297 
298 	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
299 }
300 EXPORT_SYMBOL_GPL(aead_register_instance);
301 
302 MODULE_LICENSE("GPL");
303 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
304