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 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/aead.h>
  16 #include <linux/err.h>
  17 #include <linux/init.h>
  18 #include <linux/kernel.h>
  19 #include <linux/module.h>
  20 #include <linux/rtnetlink.h>
  21 #include <linux/sched.h>
  22 #include <linux/slab.h>
  23 #include <linux/seq_file.h>
  24 #include <linux/cryptouser.h>
  25 #include <net/netlink.h>
  26
  27 #include "internal.h"
  28
  29 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  30                             unsigned int keylen)
  31 {
  32         struct aead_alg *aead = crypto_aead_alg(tfm);
  33         unsigned long alignmask = crypto_aead_alignmask(tfm);
  34         int ret;
  35         u8 *buffer, *alignbuffer;
  36         unsigned long absize;
  37
  38         absize = keylen + alignmask;
  39         buffer = kmalloc(absize, GFP_ATOMIC);
  40         if (!buffer)
  41                 return -ENOMEM;
  42
  43         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  44         memcpy(alignbuffer, key, keylen);
  45         ret = aead->setkey(tfm, alignbuffer, keylen);
  46         memset(alignbuffer, 0, keylen);
  47         kfree(buffer);
  48         return ret;
  49 }
  50
  51 static int setkey(struct crypto_aead *tfm, const u8 *key, unsigned int keylen)
  52 {
  53         struct aead_alg *aead = crypto_aead_alg(tfm);
  54         unsigned long alignmask = crypto_aead_alignmask(tfm);
  55
  56         if ((unsigned long)key & alignmask)
  57                 return setkey_unaligned(tfm, key, keylen);
  58
  59         return aead->setkey(tfm, key, keylen);
  60 }
  61
  62 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  63 {
  64         struct aead_tfm *crt = crypto_aead_crt(tfm);
  65         int err;
  66
  67         if (authsize > crypto_aead_alg(tfm)->maxauthsize)
  68                 return -EINVAL;
  69
  70         if (crypto_aead_alg(tfm)->setauthsize) {
  71                 err = crypto_aead_alg(tfm)->setauthsize(crt->base, authsize);
  72                 if (err)
  73                         return err;
  74         }
  75
  76         crypto_aead_crt(crt->base)->authsize = authsize;
  77         crt->authsize = authsize;
  78         return 0;
  79 }
  80 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  81
  82 static unsigned int crypto_aead_ctxsize(struct crypto_alg *alg, u32 type,
  83                                         u32 mask)
  84 {
  85         return alg->cra_ctxsize;
  86 }
  87
  88 static int no_givcrypt(struct aead_givcrypt_request *req)
  89 {
  90         return -ENOSYS;
  91 }
  92
  93 static int crypto_init_aead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
  94 {
  95         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
  96         struct aead_tfm *crt = &tfm->crt_aead;
  97
  98         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
  99                 return -EINVAL;
 100
 101         crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
 102                       alg->setkey : setkey;
 103         crt->encrypt = alg->encrypt;
 104         crt->decrypt = alg->decrypt;
 105         crt->givencrypt = alg->givencrypt ?: no_givcrypt;
 106         crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
 107         crt->base = __crypto_aead_cast(tfm);
 108         crt->ivsize = alg->ivsize;
 109         crt->authsize = alg->maxauthsize;
 110
 111         return 0;
 112 }
 113
 114 #ifdef CONFIG_NET
 115 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 116 {
 117         struct crypto_report_aead raead;
 118         struct aead_alg *aead = &alg->cra_aead;
 119
 120         strncpy(raead.type, "aead", sizeof(raead.type));
 121         strncpy(raead.geniv, aead->geniv ?: "<built-in>", sizeof(raead.geniv));
 122
 123         raead.blocksize = alg->cra_blocksize;
 124         raead.maxauthsize = aead->maxauthsize;
 125         raead.ivsize = aead->ivsize;
 126
 127         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 128                     sizeof(struct crypto_report_aead), &raead))
 129                 goto nla_put_failure;
 130         return 0;
 131
 132 nla_put_failure:
 133         return -EMSGSIZE;
 134 }
 135 #else
 136 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 137 {
 138         return -ENOSYS;
 139 }
 140 #endif
 141
 142 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 143         __attribute__ ((unused));
 144 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 145 {
 146         struct aead_alg *aead = &alg->cra_aead;
 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        : %s\n", aead->geniv ?: "<built-in>");
 155 }
 156
 157 const struct crypto_type crypto_aead_type = {
 158         .ctxsize = crypto_aead_ctxsize,
 159         .init = crypto_init_aead_ops,
 160 #ifdef CONFIG_PROC_FS
 161         .show = crypto_aead_show,
 162 #endif
 163         .report = crypto_aead_report,
 164 };
 165 EXPORT_SYMBOL_GPL(crypto_aead_type);
 166
 167 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
 168 {
 169         return crypto_aead_encrypt(&req->areq);
 170 }
 171
 172 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
 173 {
 174         return crypto_aead_decrypt(&req->areq);
 175 }
 176
 177 static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 178 {
 179         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
 180         struct aead_tfm *crt = &tfm->crt_aead;
 181
 182         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
 183                 return -EINVAL;
 184
 185         crt->setkey = setkey;
 186         crt->encrypt = alg->encrypt;
 187         crt->decrypt = alg->decrypt;
 188         if (!alg->ivsize) {
 189                 crt->givencrypt = aead_null_givencrypt;
 190                 crt->givdecrypt = aead_null_givdecrypt;
 191         }
 192         crt->base = __crypto_aead_cast(tfm);
 193         crt->ivsize = alg->ivsize;
 194         crt->authsize = alg->maxauthsize;
 195
 196         return 0;
 197 }
 198
 199 #ifdef CONFIG_NET
 200 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 201 {
 202         struct crypto_report_aead raead;
 203         struct aead_alg *aead = &alg->cra_aead;
 204
 205         strncpy(raead.type, "nivaead", sizeof(raead.type));
 206         strncpy(raead.geniv, aead->geniv, sizeof(raead.geniv));
 207
 208         raead.blocksize = alg->cra_blocksize;
 209         raead.maxauthsize = aead->maxauthsize;
 210         raead.ivsize = aead->ivsize;
 211
 212         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 213                     sizeof(struct crypto_report_aead), &raead))
 214                 goto nla_put_failure;
 215         return 0;
 216
 217 nla_put_failure:
 218         return -EMSGSIZE;
 219 }
 220 #else
 221 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 222 {
 223         return -ENOSYS;
 224 }
 225 #endif
 226
 227
 228 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 229         __attribute__ ((unused));
 230 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 231 {
 232         struct aead_alg *aead = &alg->cra_aead;
 233
 234         seq_printf(m, "type         : nivaead\n");
 235         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 236                                              "yes" : "no");
 237         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 238         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 239         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 240         seq_printf(m, "geniv        : %s\n", aead->geniv);
 241 }
 242
 243 const struct crypto_type crypto_nivaead_type = {
 244         .ctxsize = crypto_aead_ctxsize,
 245         .init = crypto_init_nivaead_ops,
 246 #ifdef CONFIG_PROC_FS
 247         .show = crypto_nivaead_show,
 248 #endif
 249         .report = crypto_nivaead_report,
 250 };
 251 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
 252
 253 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
 254                                const char *name, u32 type, u32 mask)
 255 {
 256         struct crypto_alg *alg;
 257         int err;
 258
 259         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 260         type |= CRYPTO_ALG_TYPE_AEAD;
 261         mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
 262
 263         alg = crypto_alg_mod_lookup(name, type, mask);
 264         if (IS_ERR(alg))
 265                 return PTR_ERR(alg);
 266
 267         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 268         crypto_mod_put(alg);
 269         return err;
 270 }
 271
 272 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 273                                          struct rtattr **tb, u32 type,
 274                                          u32 mask)
 275 {
 276         const char *name;
 277         struct crypto_aead_spawn *spawn;
 278         struct crypto_attr_type *algt;
 279         struct crypto_instance *inst;
 280         struct crypto_alg *alg;
 281         int err;
 282
 283         algt = crypto_get_attr_type(tb);
 284         if (IS_ERR(algt))
 285                 return ERR_CAST(algt);
 286
 287         if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
 288             algt->mask)
 289                 return ERR_PTR(-EINVAL);
 290
 291         name = crypto_attr_alg_name(tb[1]);
 292         if (IS_ERR(name))
 293                 return ERR_CAST(name);
 294
 295         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 296         if (!inst)
 297                 return ERR_PTR(-ENOMEM);
 298
 299         spawn = crypto_instance_ctx(inst);
 300
 301         /* Ignore async algorithms if necessary. */
 302         mask |= crypto_requires_sync(algt->type, algt->mask);
 303
 304         crypto_set_aead_spawn(spawn, inst);
 305         err = crypto_grab_nivaead(spawn, name, type, mask);
 306         if (err)
 307                 goto err_free_inst;
 308
 309         alg = crypto_aead_spawn_alg(spawn);
 310
 311         err = -EINVAL;
 312         if (!alg->cra_aead.ivsize)
 313                 goto err_drop_alg;
 314
 315         /*
 316          * This is only true if we're constructing an algorithm with its
 317          * default IV generator.  For the default generator we elide the
 318          * template name and double-check the IV generator.
 319          */
 320         if (algt->mask & CRYPTO_ALG_GENIV) {
 321                 if (strcmp(tmpl->name, alg->cra_aead.geniv))
 322                         goto err_drop_alg;
 323
 324                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 325                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 326                        CRYPTO_MAX_ALG_NAME);
 327         } else {
 328                 err = -ENAMETOOLONG;
 329                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 330                              "%s(%s)", tmpl->name, alg->cra_name) >=
 331                     CRYPTO_MAX_ALG_NAME)
 332                         goto err_drop_alg;
 333                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 334                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 335                     CRYPTO_MAX_ALG_NAME)
 336                         goto err_drop_alg;
 337         }
 338
 339         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
 340         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 341         inst->alg.cra_priority = alg->cra_priority;
 342         inst->alg.cra_blocksize = alg->cra_blocksize;
 343         inst->alg.cra_alignmask = alg->cra_alignmask;
 344         inst->alg.cra_type = &crypto_aead_type;
 345
 346         inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
 347         inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
 348         inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
 349
 350         inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
 351         inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
 352         inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
 353         inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
 354
 355 out:
 356         return inst;
 357
 358 err_drop_alg:
 359         crypto_drop_aead(spawn);
 360 err_free_inst:
 361         kfree(inst);
 362         inst = ERR_PTR(err);
 363         goto out;
 364 }
 365 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 366
 367 void aead_geniv_free(struct crypto_instance *inst)
 368 {
 369         crypto_drop_aead(crypto_instance_ctx(inst));
 370         kfree(inst);
 371 }
 372 EXPORT_SYMBOL_GPL(aead_geniv_free);
 373
 374 int aead_geniv_init(struct crypto_tfm *tfm)
 375 {
 376         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 377         struct crypto_aead *aead;
 378
 379         aead = crypto_spawn_aead(crypto_instance_ctx(inst));
 380         if (IS_ERR(aead))
 381                 return PTR_ERR(aead);
 382
 383         tfm->crt_aead.base = aead;
 384         tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
 385
 386         return 0;
 387 }
 388 EXPORT_SYMBOL_GPL(aead_geniv_init);
 389
 390 void aead_geniv_exit(struct crypto_tfm *tfm)
 391 {
 392         crypto_free_aead(tfm->crt_aead.base);
 393 }
 394 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 395
 396 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
 397 {
 398         struct rtattr *tb[3];
 399         struct {
 400                 struct rtattr attr;
 401                 struct crypto_attr_type data;
 402         } ptype;
 403         struct {
 404                 struct rtattr attr;
 405                 struct crypto_attr_alg data;
 406         } palg;
 407         struct crypto_template *tmpl;
 408         struct crypto_instance *inst;
 409         struct crypto_alg *larval;
 410         const char *geniv;
 411         int err;
 412
 413         larval = crypto_larval_lookup(alg->cra_driver_name,
 414                                       CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
 415                                       CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 416         err = PTR_ERR(larval);
 417         if (IS_ERR(larval))
 418                 goto out;
 419
 420         err = -EAGAIN;
 421         if (!crypto_is_larval(larval))
 422                 goto drop_larval;
 423
 424         ptype.attr.rta_len = sizeof(ptype);
 425         ptype.attr.rta_type = CRYPTOA_TYPE;
 426         ptype.data.type = type | CRYPTO_ALG_GENIV;
 427         /* GENIV tells the template that we're making a default geniv. */
 428         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 429         tb[0] = &ptype.attr;
 430
 431         palg.attr.rta_len = sizeof(palg);
 432         palg.attr.rta_type = CRYPTOA_ALG;
 433         /* Must use the exact name to locate ourselves. */
 434         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 435         tb[1] = &palg.attr;
 436
 437         tb[2] = NULL;
 438
 439         geniv = alg->cra_aead.geniv;
 440
 441         tmpl = crypto_lookup_template(geniv);
 442         err = -ENOENT;
 443         if (!tmpl)
 444                 goto kill_larval;
 445
 446         inst = tmpl->alloc(tb);
 447         err = PTR_ERR(inst);
 448         if (IS_ERR(inst))
 449                 goto put_tmpl;
 450
 451         err = crypto_register_instance(tmpl, inst);
 452         if (err) {
 453                 tmpl->free(inst);
 454                 goto put_tmpl;
 455         }
 456
 457         /* Redo the lookup to use the instance we just registered. */
 458         err = -EAGAIN;
 459
 460 put_tmpl:
 461         crypto_tmpl_put(tmpl);
 462 kill_larval:
 463         crypto_larval_kill(larval);
 464 drop_larval:
 465         crypto_mod_put(larval);
 466 out:
 467         crypto_mod_put(alg);
 468         return err;
 469 }
 470
 471 struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask)
 472 {
 473         struct crypto_alg *alg;
 474
 475         alg = crypto_alg_mod_lookup(name, type, mask);
 476         if (IS_ERR(alg))
 477                 return alg;
 478
 479         if (alg->cra_type == &crypto_aead_type)
 480                 return alg;
 481
 482         if (!alg->cra_aead.ivsize)
 483                 return alg;
 484
 485         crypto_mod_put(alg);
 486         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 487                                     mask & ~CRYPTO_ALG_TESTED);
 488         if (IS_ERR(alg))
 489                 return alg;
 490
 491         if (alg->cra_type == &crypto_aead_type) {
 492                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 493                         crypto_mod_put(alg);
 494                         alg = ERR_PTR(-ENOENT);
 495                 }
 496                 return alg;
 497         }
 498
 499         BUG_ON(!alg->cra_aead.ivsize);
 500
 501         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 502 }
 503 EXPORT_SYMBOL_GPL(crypto_lookup_aead);
 504
 505 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 506                      u32 type, u32 mask)
 507 {
 508         struct crypto_alg *alg;
 509         int err;
 510
 511         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 512         type |= CRYPTO_ALG_TYPE_AEAD;
 513         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 514         mask |= CRYPTO_ALG_TYPE_MASK;
 515
 516         alg = crypto_lookup_aead(name, type, mask);
 517         if (IS_ERR(alg))
 518                 return PTR_ERR(alg);
 519
 520         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 521         crypto_mod_put(alg);
 522         return err;
 523 }
 524 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 525
 526 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 527 {
 528         struct crypto_tfm *tfm;
 529         int err;
 530
 531         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 532         type |= CRYPTO_ALG_TYPE_AEAD;
 533         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 534         mask |= CRYPTO_ALG_TYPE_MASK;
 535
 536         for (;;) {
 537                 struct crypto_alg *alg;
 538
 539                 alg = crypto_lookup_aead(alg_name, type, mask);
 540                 if (IS_ERR(alg)) {
 541                         err = PTR_ERR(alg);
 542                         goto err;
 543                 }
 544
 545                 tfm = __crypto_alloc_tfm(alg, type, mask);
 546                 if (!IS_ERR(tfm))
 547                         return __crypto_aead_cast(tfm);
 548
 549                 crypto_mod_put(alg);
 550                 err = PTR_ERR(tfm);
 551
 552 err:
 553                 if (err != -EAGAIN)
 554                         break;
 555                 if (signal_pending(current)) {
 556                         err = -EINTR;
 557                         break;
 558                 }
 559         }
 560
 561         return ERR_PTR(err);
 562 }
 563 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 564
 565 MODULE_LICENSE("GPL");
 566 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");