1 /*
2 * AEAD: Authenticated Encryption with Associated Data
3 *
4 * This file provides API support for AEAD algorithms.
5 *
6 * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
7 *
8 * This program is free software; you can redistribute it and/or modify it
9 * under the terms of the GNU General Public License as published by the Free
10 * Software Foundation; either version 2 of the License, or (at your option)
11 * any later version.
12 *
13 */
14
15 #include <crypto/internal/geniv.h>
16 #include <crypto/internal/rng.h>
17 #include <crypto/null.h>
18 #include <crypto/scatterwalk.h>
19 #include <linux/err.h>
20 #include <linux/init.h>
21 #include <linux/kernel.h>
22 #include <linux/module.h>
23 #include <linux/rtnetlink.h>
24 #include <linux/slab.h>
25 #include <linux/seq_file.h>
26 #include <linux/cryptouser.h>
27 #include <linux/compiler.h>
28 #include <net/netlink.h>
29
30 #include "internal.h"
31
setkey_unaligned(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)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
crypto_aead_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)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 (err)
65 return err;
66
67 crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
68 return 0;
69 }
70 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
71
crypto_aead_setauthsize(struct crypto_aead * tfm,unsigned int authsize)72 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
73 {
74 int err;
75
76 if (authsize > crypto_aead_maxauthsize(tfm))
77 return -EINVAL;
78
79 if (crypto_aead_alg(tfm)->setauthsize) {
80 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
81 if (err)
82 return err;
83 }
84
85 tfm->authsize = authsize;
86 return 0;
87 }
88 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
89
crypto_aead_exit_tfm(struct crypto_tfm * tfm)90 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
91 {
92 struct crypto_aead *aead = __crypto_aead_cast(tfm);
93 struct aead_alg *alg = crypto_aead_alg(aead);
94
95 alg->exit(aead);
96 }
97
crypto_aead_init_tfm(struct crypto_tfm * tfm)98 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
99 {
100 struct crypto_aead *aead = __crypto_aead_cast(tfm);
101 struct aead_alg *alg = crypto_aead_alg(aead);
102
103 crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
104
105 aead->authsize = alg->maxauthsize;
106
107 if (alg->exit)
108 aead->base.exit = crypto_aead_exit_tfm;
109
110 if (alg->init)
111 return alg->init(aead);
112
113 return 0;
114 }
115
116 #ifdef CONFIG_NET
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)117 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
118 {
119 struct crypto_report_aead raead;
120 struct aead_alg *aead = container_of(alg, struct aead_alg, base);
121
122 strncpy(raead.type, "aead", sizeof(raead.type));
123 strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
124
125 raead.blocksize = alg->cra_blocksize;
126 raead.maxauthsize = aead->maxauthsize;
127 raead.ivsize = aead->ivsize;
128
129 if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
130 sizeof(struct crypto_report_aead), &raead))
131 goto nla_put_failure;
132 return 0;
133
134 nla_put_failure:
135 return -EMSGSIZE;
136 }
137 #else
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)138 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
139 {
140 return -ENOSYS;
141 }
142 #endif
143
144 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
145 __maybe_unused;
crypto_aead_show(struct seq_file * m,struct crypto_alg * alg)146 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
147 {
148 struct aead_alg *aead = container_of(alg, struct aead_alg, base);
149
150 seq_printf(m, "type : aead\n");
151 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
152 "yes" : "no");
153 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
154 seq_printf(m, "ivsize : %u\n", aead->ivsize);
155 seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
156 seq_printf(m, "geniv : <none>\n");
157 }
158
crypto_aead_free_instance(struct crypto_instance * inst)159 static void crypto_aead_free_instance(struct crypto_instance *inst)
160 {
161 struct aead_instance *aead = aead_instance(inst);
162
163 if (!aead->free) {
164 inst->tmpl->free(inst);
165 return;
166 }
167
168 aead->free(aead);
169 }
170
171 static const struct crypto_type crypto_aead_type = {
172 .extsize = crypto_alg_extsize,
173 .init_tfm = crypto_aead_init_tfm,
174 .free = crypto_aead_free_instance,
175 #ifdef CONFIG_PROC_FS
176 .show = crypto_aead_show,
177 #endif
178 .report = crypto_aead_report,
179 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
180 .maskset = CRYPTO_ALG_TYPE_MASK,
181 .type = CRYPTO_ALG_TYPE_AEAD,
182 .tfmsize = offsetof(struct crypto_aead, base),
183 };
184
aead_geniv_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)185 static int aead_geniv_setkey(struct crypto_aead *tfm,
186 const u8 *key, unsigned int keylen)
187 {
188 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
189
190 return crypto_aead_setkey(ctx->child, key, keylen);
191 }
192
aead_geniv_setauthsize(struct crypto_aead * tfm,unsigned int authsize)193 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
194 unsigned int authsize)
195 {
196 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
197
198 return crypto_aead_setauthsize(ctx->child, authsize);
199 }
200
aead_geniv_alloc(struct crypto_template * tmpl,struct rtattr ** tb,u32 type,u32 mask)201 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
202 struct rtattr **tb, u32 type, u32 mask)
203 {
204 const char *name;
205 struct crypto_aead_spawn *spawn;
206 struct crypto_attr_type *algt;
207 struct aead_instance *inst;
208 struct aead_alg *alg;
209 unsigned int ivsize;
210 unsigned int maxauthsize;
211 int err;
212
213 algt = crypto_get_attr_type(tb);
214 if (IS_ERR(algt))
215 return ERR_CAST(algt);
216
217 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
218 return ERR_PTR(-EINVAL);
219
220 name = crypto_attr_alg_name(tb[1]);
221 if (IS_ERR(name))
222 return ERR_CAST(name);
223
224 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
225 if (!inst)
226 return ERR_PTR(-ENOMEM);
227
228 spawn = aead_instance_ctx(inst);
229
230 /* Ignore async algorithms if necessary. */
231 mask |= crypto_requires_sync(algt->type, algt->mask);
232
233 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
234 err = crypto_grab_aead(spawn, name, type, mask);
235 if (err)
236 goto err_free_inst;
237
238 alg = crypto_spawn_aead_alg(spawn);
239
240 ivsize = crypto_aead_alg_ivsize(alg);
241 maxauthsize = crypto_aead_alg_maxauthsize(alg);
242
243 err = -EINVAL;
244 if (ivsize < sizeof(u64))
245 goto err_drop_alg;
246
247 err = -ENAMETOOLONG;
248 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
249 "%s(%s)", tmpl->name, alg->base.cra_name) >=
250 CRYPTO_MAX_ALG_NAME)
251 goto err_drop_alg;
252 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
253 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
254 CRYPTO_MAX_ALG_NAME)
255 goto err_drop_alg;
256
257 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
258 inst->alg.base.cra_priority = alg->base.cra_priority;
259 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
260 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
261 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
262
263 inst->alg.setkey = aead_geniv_setkey;
264 inst->alg.setauthsize = aead_geniv_setauthsize;
265
266 inst->alg.ivsize = ivsize;
267 inst->alg.maxauthsize = maxauthsize;
268
269 out:
270 return inst;
271
272 err_drop_alg:
273 crypto_drop_aead(spawn);
274 err_free_inst:
275 kfree(inst);
276 inst = ERR_PTR(err);
277 goto out;
278 }
279 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
280
aead_geniv_free(struct aead_instance * inst)281 void aead_geniv_free(struct aead_instance *inst)
282 {
283 crypto_drop_aead(aead_instance_ctx(inst));
284 kfree(inst);
285 }
286 EXPORT_SYMBOL_GPL(aead_geniv_free);
287
aead_init_geniv(struct crypto_aead * aead)288 int aead_init_geniv(struct crypto_aead *aead)
289 {
290 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
291 struct aead_instance *inst = aead_alg_instance(aead);
292 struct crypto_aead *child;
293 int err;
294
295 spin_lock_init(&ctx->lock);
296
297 err = crypto_get_default_rng();
298 if (err)
299 goto out;
300
301 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
302 crypto_aead_ivsize(aead));
303 crypto_put_default_rng();
304 if (err)
305 goto out;
306
307 ctx->sknull = crypto_get_default_null_skcipher();
308 err = PTR_ERR(ctx->sknull);
309 if (IS_ERR(ctx->sknull))
310 goto out;
311
312 child = crypto_spawn_aead(aead_instance_ctx(inst));
313 err = PTR_ERR(child);
314 if (IS_ERR(child))
315 goto drop_null;
316
317 ctx->child = child;
318 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
319 sizeof(struct aead_request));
320
321 err = 0;
322
323 out:
324 return err;
325
326 drop_null:
327 crypto_put_default_null_skcipher();
328 goto out;
329 }
330 EXPORT_SYMBOL_GPL(aead_init_geniv);
331
aead_exit_geniv(struct crypto_aead * tfm)332 void aead_exit_geniv(struct crypto_aead *tfm)
333 {
334 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
335
336 crypto_free_aead(ctx->child);
337 crypto_put_default_null_skcipher();
338 }
339 EXPORT_SYMBOL_GPL(aead_exit_geniv);
340
crypto_grab_aead(struct crypto_aead_spawn * spawn,const char * name,u32 type,u32 mask)341 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
342 u32 type, u32 mask)
343 {
344 spawn->base.frontend = &crypto_aead_type;
345 return crypto_grab_spawn(&spawn->base, name, type, mask);
346 }
347 EXPORT_SYMBOL_GPL(crypto_grab_aead);
348
crypto_alloc_aead(const char * alg_name,u32 type,u32 mask)349 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
350 {
351 return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
352 }
353 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
354
aead_prepare_alg(struct aead_alg * alg)355 static int aead_prepare_alg(struct aead_alg *alg)
356 {
357 struct crypto_alg *base = &alg->base;
358
359 if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
360 PAGE_SIZE / 8)
361 return -EINVAL;
362
363 if (!alg->chunksize)
364 alg->chunksize = base->cra_blocksize;
365
366 base->cra_type = &crypto_aead_type;
367 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
368 base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
369
370 return 0;
371 }
372
crypto_register_aead(struct aead_alg * alg)373 int crypto_register_aead(struct aead_alg *alg)
374 {
375 struct crypto_alg *base = &alg->base;
376 int err;
377
378 err = aead_prepare_alg(alg);
379 if (err)
380 return err;
381
382 return crypto_register_alg(base);
383 }
384 EXPORT_SYMBOL_GPL(crypto_register_aead);
385
crypto_unregister_aead(struct aead_alg * alg)386 void crypto_unregister_aead(struct aead_alg *alg)
387 {
388 crypto_unregister_alg(&alg->base);
389 }
390 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
391
crypto_register_aeads(struct aead_alg * algs,int count)392 int crypto_register_aeads(struct aead_alg *algs, int count)
393 {
394 int i, ret;
395
396 for (i = 0; i < count; i++) {
397 ret = crypto_register_aead(&algs[i]);
398 if (ret)
399 goto err;
400 }
401
402 return 0;
403
404 err:
405 for (--i; i >= 0; --i)
406 crypto_unregister_aead(&algs[i]);
407
408 return ret;
409 }
410 EXPORT_SYMBOL_GPL(crypto_register_aeads);
411
crypto_unregister_aeads(struct aead_alg * algs,int count)412 void crypto_unregister_aeads(struct aead_alg *algs, int count)
413 {
414 int i;
415
416 for (i = count - 1; i >= 0; --i)
417 crypto_unregister_aead(&algs[i]);
418 }
419 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
420
aead_register_instance(struct crypto_template * tmpl,struct aead_instance * inst)421 int aead_register_instance(struct crypto_template *tmpl,
422 struct aead_instance *inst)
423 {
424 int err;
425
426 err = aead_prepare_alg(&inst->alg);
427 if (err)
428 return err;
429
430 return crypto_register_instance(tmpl, aead_crypto_instance(inst));
431 }
432 EXPORT_SYMBOL_GPL(aead_register_instance);
433
434 MODULE_LICENSE("GPL");
435 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
436
