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 (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
crypto_aead_setauthsize(struct crypto_aead * tfm,unsigned int authsize)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 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
crypto_aead_exit_tfm(struct crypto_tfm * tfm)92 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
93 {
94 struct crypto_aead *aead = __crypto_aead_cast(tfm);
95 struct aead_alg *alg = crypto_aead_alg(aead);
96
97 alg->exit(aead);
98 }
99
crypto_aead_init_tfm(struct crypto_tfm * tfm)100 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
101 {
102 struct crypto_aead *aead = __crypto_aead_cast(tfm);
103 struct aead_alg *alg = crypto_aead_alg(aead);
104
105 crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
106
107 aead->authsize = alg->maxauthsize;
108
109 if (alg->exit)
110 aead->base.exit = crypto_aead_exit_tfm;
111
112 if (alg->init)
113 return alg->init(aead);
114
115 return 0;
116 }
117
118 #ifdef CONFIG_NET
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)119 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
120 {
121 struct crypto_report_aead raead;
122 struct aead_alg *aead = container_of(alg, struct aead_alg, base);
123
124 strncpy(raead.type, "aead", sizeof(raead.type));
125 strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
126
127 raead.blocksize = alg->cra_blocksize;
128 raead.maxauthsize = aead->maxauthsize;
129 raead.ivsize = aead->ivsize;
130
131 if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
132 sizeof(struct crypto_report_aead), &raead))
133 goto nla_put_failure;
134 return 0;
135
136 nla_put_failure:
137 return -EMSGSIZE;
138 }
139 #else
crypto_aead_report(struct sk_buff * skb,struct crypto_alg * alg)140 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
141 {
142 return -ENOSYS;
143 }
144 #endif
145
146 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
147 __maybe_unused;
crypto_aead_show(struct seq_file * m,struct crypto_alg * alg)148 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
149 {
150 struct aead_alg *aead = container_of(alg, struct aead_alg, base);
151
152 seq_printf(m, "type : aead\n");
153 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
154 "yes" : "no");
155 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
156 seq_printf(m, "ivsize : %u\n", aead->ivsize);
157 seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
158 seq_printf(m, "geniv : <none>\n");
159 }
160
crypto_aead_free_instance(struct crypto_instance * inst)161 static void crypto_aead_free_instance(struct crypto_instance *inst)
162 {
163 struct aead_instance *aead = aead_instance(inst);
164
165 if (!aead->free) {
166 inst->tmpl->free(inst);
167 return;
168 }
169
170 aead->free(aead);
171 }
172
173 static const struct crypto_type crypto_aead_type = {
174 .extsize = crypto_alg_extsize,
175 .init_tfm = crypto_aead_init_tfm,
176 .free = crypto_aead_free_instance,
177 #ifdef CONFIG_PROC_FS
178 .show = crypto_aead_show,
179 #endif
180 .report = crypto_aead_report,
181 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
182 .maskset = CRYPTO_ALG_TYPE_MASK,
183 .type = CRYPTO_ALG_TYPE_AEAD,
184 .tfmsize = offsetof(struct crypto_aead, base),
185 };
186
aead_geniv_setkey(struct crypto_aead * tfm,const u8 * key,unsigned int keylen)187 static int aead_geniv_setkey(struct crypto_aead *tfm,
188 const u8 *key, unsigned int keylen)
189 {
190 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
191
192 return crypto_aead_setkey(ctx->child, key, keylen);
193 }
194
aead_geniv_setauthsize(struct crypto_aead * tfm,unsigned int authsize)195 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
196 unsigned int authsize)
197 {
198 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
199
200 return crypto_aead_setauthsize(ctx->child, authsize);
201 }
202
aead_geniv_alloc(struct crypto_template * tmpl,struct rtattr ** tb,u32 type,u32 mask)203 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
204 struct rtattr **tb, u32 type, u32 mask)
205 {
206 const char *name;
207 struct crypto_aead_spawn *spawn;
208 struct crypto_attr_type *algt;
209 struct aead_instance *inst;
210 struct aead_alg *alg;
211 unsigned int ivsize;
212 unsigned int maxauthsize;
213 int err;
214
215 algt = crypto_get_attr_type(tb);
216 if (IS_ERR(algt))
217 return ERR_CAST(algt);
218
219 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
220 return ERR_PTR(-EINVAL);
221
222 name = crypto_attr_alg_name(tb[1]);
223 if (IS_ERR(name))
224 return ERR_CAST(name);
225
226 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
227 if (!inst)
228 return ERR_PTR(-ENOMEM);
229
230 spawn = aead_instance_ctx(inst);
231
232 /* Ignore async algorithms if necessary. */
233 mask |= crypto_requires_sync(algt->type, algt->mask);
234
235 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
236 err = crypto_grab_aead(spawn, name, type, mask);
237 if (err)
238 goto err_free_inst;
239
240 alg = crypto_spawn_aead_alg(spawn);
241
242 ivsize = crypto_aead_alg_ivsize(alg);
243 maxauthsize = crypto_aead_alg_maxauthsize(alg);
244
245 err = -EINVAL;
246 if (ivsize < sizeof(u64))
247 goto err_drop_alg;
248
249 err = -ENAMETOOLONG;
250 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
251 "%s(%s)", tmpl->name, alg->base.cra_name) >=
252 CRYPTO_MAX_ALG_NAME)
253 goto err_drop_alg;
254 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
255 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
256 CRYPTO_MAX_ALG_NAME)
257 goto err_drop_alg;
258
259 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
260 inst->alg.base.cra_priority = alg->base.cra_priority;
261 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
262 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
263 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
264
265 inst->alg.setkey = aead_geniv_setkey;
266 inst->alg.setauthsize = aead_geniv_setauthsize;
267
268 inst->alg.ivsize = ivsize;
269 inst->alg.maxauthsize = maxauthsize;
270
271 out:
272 return inst;
273
274 err_drop_alg:
275 crypto_drop_aead(spawn);
276 err_free_inst:
277 kfree(inst);
278 inst = ERR_PTR(err);
279 goto out;
280 }
281 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
282
aead_geniv_free(struct aead_instance * inst)283 void aead_geniv_free(struct aead_instance *inst)
284 {
285 crypto_drop_aead(aead_instance_ctx(inst));
286 kfree(inst);
287 }
288 EXPORT_SYMBOL_GPL(aead_geniv_free);
289
aead_init_geniv(struct crypto_aead * aead)290 int aead_init_geniv(struct crypto_aead *aead)
291 {
292 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
293 struct aead_instance *inst = aead_alg_instance(aead);
294 struct crypto_aead *child;
295 int err;
296
297 spin_lock_init(&ctx->lock);
298
299 err = crypto_get_default_rng();
300 if (err)
301 goto out;
302
303 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
304 crypto_aead_ivsize(aead));
305 crypto_put_default_rng();
306 if (err)
307 goto out;
308
309 ctx->sknull = crypto_get_default_null_skcipher();
310 err = PTR_ERR(ctx->sknull);
311 if (IS_ERR(ctx->sknull))
312 goto out;
313
314 child = crypto_spawn_aead(aead_instance_ctx(inst));
315 err = PTR_ERR(child);
316 if (IS_ERR(child))
317 goto drop_null;
318
319 ctx->child = child;
320 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
321 sizeof(struct aead_request));
322
323 err = 0;
324
325 out:
326 return err;
327
328 drop_null:
329 crypto_put_default_null_skcipher();
330 goto out;
331 }
332 EXPORT_SYMBOL_GPL(aead_init_geniv);
333
aead_exit_geniv(struct crypto_aead * tfm)334 void aead_exit_geniv(struct crypto_aead *tfm)
335 {
336 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
337
338 crypto_free_aead(ctx->child);
339 crypto_put_default_null_skcipher();
340 }
341 EXPORT_SYMBOL_GPL(aead_exit_geniv);
342
crypto_grab_aead(struct crypto_aead_spawn * spawn,const char * name,u32 type,u32 mask)343 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
344 u32 type, u32 mask)
345 {
346 spawn->base.frontend = &crypto_aead_type;
347 return crypto_grab_spawn(&spawn->base, name, type, mask);
348 }
349 EXPORT_SYMBOL_GPL(crypto_grab_aead);
350
crypto_alloc_aead(const char * alg_name,u32 type,u32 mask)351 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
352 {
353 return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
354 }
355 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
356
aead_prepare_alg(struct aead_alg * alg)357 static int aead_prepare_alg(struct aead_alg *alg)
358 {
359 struct crypto_alg *base = &alg->base;
360
361 if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
362 PAGE_SIZE / 8)
363 return -EINVAL;
364
365 if (!alg->chunksize)
366 alg->chunksize = base->cra_blocksize;
367
368 base->cra_type = &crypto_aead_type;
369 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
370 base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
371
372 return 0;
373 }
374
crypto_register_aead(struct aead_alg * alg)375 int crypto_register_aead(struct aead_alg *alg)
376 {
377 struct crypto_alg *base = &alg->base;
378 int err;
379
380 err = aead_prepare_alg(alg);
381 if (err)
382 return err;
383
384 return crypto_register_alg(base);
385 }
386 EXPORT_SYMBOL_GPL(crypto_register_aead);
387
crypto_unregister_aead(struct aead_alg * alg)388 void crypto_unregister_aead(struct aead_alg *alg)
389 {
390 crypto_unregister_alg(&alg->base);
391 }
392 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
393
crypto_register_aeads(struct aead_alg * algs,int count)394 int crypto_register_aeads(struct aead_alg *algs, int count)
395 {
396 int i, ret;
397
398 for (i = 0; i < count; i++) {
399 ret = crypto_register_aead(&algs[i]);
400 if (ret)
401 goto err;
402 }
403
404 return 0;
405
406 err:
407 for (--i; i >= 0; --i)
408 crypto_unregister_aead(&algs[i]);
409
410 return ret;
411 }
412 EXPORT_SYMBOL_GPL(crypto_register_aeads);
413
crypto_unregister_aeads(struct aead_alg * algs,int count)414 void crypto_unregister_aeads(struct aead_alg *algs, int count)
415 {
416 int i;
417
418 for (i = count - 1; i >= 0; --i)
419 crypto_unregister_aead(&algs[i]);
420 }
421 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
422
aead_register_instance(struct crypto_template * tmpl,struct aead_instance * inst)423 int aead_register_instance(struct crypto_template *tmpl,
424 struct aead_instance *inst)
425 {
426 int err;
427
428 err = aead_prepare_alg(&inst->alg);
429 if (err)
430 return err;
431
432 return crypto_register_instance(tmpl, aead_crypto_instance(inst));
433 }
434 EXPORT_SYMBOL_GPL(aead_register_instance);
435
436 MODULE_LICENSE("GPL");
437 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
438