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
32static 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
53int 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}
72EXPORT_SYMBOL_GPL(crypto_aead_setkey);
73
74int 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}
90EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
91
92static 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
100static 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
119static 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 memset(&raead, 0, sizeof(raead));
125
126 strscpy(raead.type, "aead", sizeof(raead.type));
127 strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
128
129 raead.blocksize = alg->cra_blocksize;
130 raead.maxauthsize = aead->maxauthsize;
131 raead.ivsize = aead->ivsize;
132
133 return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
134}
135#else
136static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
137{
138 return -ENOSYS;
139}
140#endif
141
142static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
143 __maybe_unused;
144static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
145{
146 struct aead_alg *aead = container_of(alg, struct aead_alg, base);
147
148 seq_printf(m, "type : aead\n");
149 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
150 "yes" : "no");
151 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
152 seq_printf(m, "ivsize : %u\n", aead->ivsize);
153 seq_printf(m, "maxauthsize : %u\n", aead->maxauthsize);
154 seq_printf(m, "geniv : <none>\n");
155}
156
157static void crypto_aead_free_instance(struct crypto_instance *inst)
158{
159 struct aead_instance *aead = aead_instance(inst);
160
161 if (!aead->free) {
162 inst->tmpl->free(inst);
163 return;
164 }
165
166 aead->free(aead);
167}
168
169static const struct crypto_type crypto_aead_type = {
170 .extsize = crypto_alg_extsize,
171 .init_tfm = crypto_aead_init_tfm,
172 .free = crypto_aead_free_instance,
173#ifdef CONFIG_PROC_FS
174 .show = crypto_aead_show,
175#endif
176 .report = crypto_aead_report,
177 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
178 .maskset = CRYPTO_ALG_TYPE_MASK,
179 .type = CRYPTO_ALG_TYPE_AEAD,
180 .tfmsize = offsetof(struct crypto_aead, base),
181};
182
183static int aead_geniv_setkey(struct crypto_aead *tfm,
184 const u8 *key, unsigned int keylen)
185{
186 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
187
188 return crypto_aead_setkey(ctx->child, key, keylen);
189}
190
191static int aead_geniv_setauthsize(struct crypto_aead *tfm,
192 unsigned int authsize)
193{
194 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
195
196 return crypto_aead_setauthsize(ctx->child, authsize);
197}
198
199struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
200 struct rtattr **tb, u32 type, u32 mask)
201{
202 const char *name;
203 struct crypto_aead_spawn *spawn;
204 struct crypto_attr_type *algt;
205 struct aead_instance *inst;
206 struct aead_alg *alg;
207 unsigned int ivsize;
208 unsigned int maxauthsize;
209 int err;
210
211 algt = crypto_get_attr_type(tb);
212 if (IS_ERR(algt))
213 return ERR_CAST(algt);
214
215 if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
216 return ERR_PTR(-EINVAL);
217
218 name = crypto_attr_alg_name(tb[1]);
219 if (IS_ERR(name))
220 return ERR_CAST(name);
221
222 inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
223 if (!inst)
224 return ERR_PTR(-ENOMEM);
225
226 spawn = aead_instance_ctx(inst);
227
228 /* Ignore async algorithms if necessary. */
229 mask |= crypto_requires_sync(algt->type, algt->mask);
230
231 crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
232 err = crypto_grab_aead(spawn, name, type, mask);
233 if (err)
234 goto err_free_inst;
235
236 alg = crypto_spawn_aead_alg(spawn);
237
238 ivsize = crypto_aead_alg_ivsize(alg);
239 maxauthsize = crypto_aead_alg_maxauthsize(alg);
240
241 err = -EINVAL;
242 if (ivsize < sizeof(u64))
243 goto err_drop_alg;
244
245 err = -ENAMETOOLONG;
246 if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
247 "%s(%s)", tmpl->name, alg->base.cra_name) >=
248 CRYPTO_MAX_ALG_NAME)
249 goto err_drop_alg;
250 if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
251 "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
252 CRYPTO_MAX_ALG_NAME)
253 goto err_drop_alg;
254
255 inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
256 inst->alg.base.cra_priority = alg->base.cra_priority;
257 inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
258 inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
259 inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
260
261 inst->alg.setkey = aead_geniv_setkey;
262 inst->alg.setauthsize = aead_geniv_setauthsize;
263
264 inst->alg.ivsize = ivsize;
265 inst->alg.maxauthsize = maxauthsize;
266
267out:
268 return inst;
269
270err_drop_alg:
271 crypto_drop_aead(spawn);
272err_free_inst:
273 kfree(inst);
274 inst = ERR_PTR(err);
275 goto out;
276}
277EXPORT_SYMBOL_GPL(aead_geniv_alloc);
278
279void aead_geniv_free(struct aead_instance *inst)
280{
281 crypto_drop_aead(aead_instance_ctx(inst));
282 kfree(inst);
283}
284EXPORT_SYMBOL_GPL(aead_geniv_free);
285
286int aead_init_geniv(struct crypto_aead *aead)
287{
288 struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
289 struct aead_instance *inst = aead_alg_instance(aead);
290 struct crypto_aead *child;
291 int err;
292
293 spin_lock_init(&ctx->lock);
294
295 err = crypto_get_default_rng();
296 if (err)
297 goto out;
298
299 err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
300 crypto_aead_ivsize(aead));
301 crypto_put_default_rng();
302 if (err)
303 goto out;
304
305 ctx->sknull = crypto_get_default_null_skcipher();
306 err = PTR_ERR(ctx->sknull);
307 if (IS_ERR(ctx->sknull))
308 goto out;
309
310 child = crypto_spawn_aead(aead_instance_ctx(inst));
311 err = PTR_ERR(child);
312 if (IS_ERR(child))
313 goto drop_null;
314
315 ctx->child = child;
316 crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
317 sizeof(struct aead_request));
318
319 err = 0;
320
321out:
322 return err;
323
324drop_null:
325 crypto_put_default_null_skcipher();
326 goto out;
327}
328EXPORT_SYMBOL_GPL(aead_init_geniv);
329
330void aead_exit_geniv(struct crypto_aead *tfm)
331{
332 struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
333
334 crypto_free_aead(ctx->child);
335 crypto_put_default_null_skcipher();
336}
337EXPORT_SYMBOL_GPL(aead_exit_geniv);
338
339int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
340 u32 type, u32 mask)
341{
342 spawn->base.frontend = &crypto_aead_type;
343 return crypto_grab_spawn(&spawn->base, name, type, mask);
344}
345EXPORT_SYMBOL_GPL(crypto_grab_aead);
346
347struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
348{
349 return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
350}
351EXPORT_SYMBOL_GPL(crypto_alloc_aead);
352
353static int aead_prepare_alg(struct aead_alg *alg)
354{
355 struct crypto_alg *base = &alg->base;
356
357 if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
358 PAGE_SIZE / 8)
359 return -EINVAL;
360
361 if (!alg->chunksize)
362 alg->chunksize = base->cra_blocksize;
363
364 base->cra_type = &crypto_aead_type;
365 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
366 base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
367
368 return 0;
369}
370
371int crypto_register_aead(struct aead_alg *alg)
372{
373 struct crypto_alg *base = &alg->base;
374 int err;
375
376 err = aead_prepare_alg(alg);
377 if (err)
378 return err;
379
380 return crypto_register_alg(base);
381}
382EXPORT_SYMBOL_GPL(crypto_register_aead);
383
384void crypto_unregister_aead(struct aead_alg *alg)
385{
386 crypto_unregister_alg(&alg->base);
387}
388EXPORT_SYMBOL_GPL(crypto_unregister_aead);
389
390int crypto_register_aeads(struct aead_alg *algs, int count)
391{
392 int i, ret;
393
394 for (i = 0; i < count; i++) {
395 ret = crypto_register_aead(&algs[i]);
396 if (ret)
397 goto err;
398 }
399
400 return 0;
401
402err:
403 for (--i; i >= 0; --i)
404 crypto_unregister_aead(&algs[i]);
405
406 return ret;
407}
408EXPORT_SYMBOL_GPL(crypto_register_aeads);
409
410void crypto_unregister_aeads(struct aead_alg *algs, int count)
411{
412 int i;
413
414 for (i = count - 1; i >= 0; --i)
415 crypto_unregister_aead(&algs[i]);
416}
417EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
418
419int aead_register_instance(struct crypto_template *tmpl,
420 struct aead_instance *inst)
421{
422 int err;
423
424 err = aead_prepare_alg(&inst->alg);
425 if (err)
426 return err;
427
428 return crypto_register_instance(tmpl, aead_crypto_instance(inst));
429}
430EXPORT_SYMBOL_GPL(aead_register_instance);
431
432MODULE_LICENSE("GPL");
433MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
434