GNU Linux-libre 4.19.211-gnu1
[releases.git] / crypto / aead.c
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
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                 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 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
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
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
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;
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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
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)");