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         snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "aead");
 121         snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s",
 122                  aead->geniv ?: "<built-in>");
 123
 124         raead.blocksize = alg->cra_blocksize;
 125         raead.maxauthsize = aead->maxauthsize;
 126         raead.ivsize = aead->ivsize;
 127
 128         NLA_PUT(skb, CRYPTOCFGA_REPORT_AEAD,
 129                 sizeof(struct crypto_report_aead), &raead);
 130
 131         return 0;
 132
 133 nla_put_failure:
 134         return -EMSGSIZE;
 135 }
 136 #else
 137 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 138 {
 139         return -ENOSYS;
 140 }
 141 #endif
 142
 143 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 144         __attribute__ ((unused));
 145 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 146 {
 147         struct aead_alg *aead = &alg->cra_aead;
 148
 149         seq_printf(m, "type         : aead\n");
 150         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 151                                              "yes" : "no");
 152         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 153         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 154         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 155         seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
 156 }
 157
 158 const struct crypto_type crypto_aead_type = {
 159         .ctxsize = crypto_aead_ctxsize,
 160         .init = crypto_init_aead_ops,
 161 #ifdef CONFIG_PROC_FS
 162         .show = crypto_aead_show,
 163 #endif
 164         .report = crypto_aead_report,
 165 };
 166 EXPORT_SYMBOL_GPL(crypto_aead_type);
 167
 168 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
 169 {
 170         return crypto_aead_encrypt(&req->areq);
 171 }
 172
 173 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
 174 {
 175         return crypto_aead_decrypt(&req->areq);
 176 }
 177
 178 static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 179 {
 180         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
 181         struct aead_tfm *crt = &tfm->crt_aead;
 182
 183         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
 184                 return -EINVAL;
 185
 186         crt->setkey = setkey;
 187         crt->encrypt = alg->encrypt;
 188         crt->decrypt = alg->decrypt;
 189         if (!alg->ivsize) {
 190                 crt->givencrypt = aead_null_givencrypt;
 191                 crt->givdecrypt = aead_null_givdecrypt;
 192         }
 193         crt->base = __crypto_aead_cast(tfm);
 194         crt->ivsize = alg->ivsize;
 195         crt->authsize = alg->maxauthsize;
 196
 197         return 0;
 198 }
 199
 200 #ifdef CONFIG_NET
 201 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 202 {
 203         struct crypto_report_aead raead;
 204         struct aead_alg *aead = &alg->cra_aead;
 205
 206         snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "nivaead");
 207         snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s", aead->geniv);
 208
 209         raead.blocksize = alg->cra_blocksize;
 210         raead.maxauthsize = aead->maxauthsize;
 211         raead.ivsize = aead->ivsize;
 212
 213         NLA_PUT(skb, CRYPTOCFGA_REPORT_AEAD,
 214                 sizeof(struct crypto_report_aead), &raead);
 215
 216         return 0;
 217
 218 nla_put_failure:
 219         return -EMSGSIZE;
 220 }
 221 #else
 222 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 223 {
 224         return -ENOSYS;
 225 }
 226 #endif
 227
 228
 229 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 230         __attribute__ ((unused));
 231 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 232 {
 233         struct aead_alg *aead = &alg->cra_aead;
 234
 235         seq_printf(m, "type         : nivaead\n");
 236         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 237                                              "yes" : "no");
 238         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 239         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 240         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 241         seq_printf(m, "geniv        : %s\n", aead->geniv);
 242 }
 243
 244 const struct crypto_type crypto_nivaead_type = {
 245         .ctxsize = crypto_aead_ctxsize,
 246         .init = crypto_init_nivaead_ops,
 247 #ifdef CONFIG_PROC_FS
 248         .show = crypto_nivaead_show,
 249 #endif
 250         .report = crypto_nivaead_report,
 251 };
 252 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
 253
 254 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
 255                                const char *name, u32 type, u32 mask)
 256 {
 257         struct crypto_alg *alg;
 258         int err;
 259
 260         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 261         type |= CRYPTO_ALG_TYPE_AEAD;
 262         mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
 263
 264         alg = crypto_alg_mod_lookup(name, type, mask);
 265         if (IS_ERR(alg))
 266                 return PTR_ERR(alg);
 267
 268         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 269         crypto_mod_put(alg);
 270         return err;
 271 }
 272
 273 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 274                                          struct rtattr **tb, u32 type,
 275                                          u32 mask)
 276 {
 277         const char *name;
 278         struct crypto_aead_spawn *spawn;
 279         struct crypto_attr_type *algt;
 280         struct crypto_instance *inst;
 281         struct crypto_alg *alg;
 282         int err;
 283
 284         algt = crypto_get_attr_type(tb);
 285         err = PTR_ERR(algt);
 286         if (IS_ERR(algt))
 287                 return ERR_PTR(err);
 288
 289         if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
 290             algt->mask)
 291                 return ERR_PTR(-EINVAL);
 292
 293         name = crypto_attr_alg_name(tb[1]);
 294         err = PTR_ERR(name);
 295         if (IS_ERR(name))
 296                 return ERR_PTR(err);
 297
 298         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 299         if (!inst)
 300                 return ERR_PTR(-ENOMEM);
 301
 302         spawn = crypto_instance_ctx(inst);
 303
 304         /* Ignore async algorithms if necessary. */
 305         mask |= crypto_requires_sync(algt->type, algt->mask);
 306
 307         crypto_set_aead_spawn(spawn, inst);
 308         err = crypto_grab_nivaead(spawn, name, type, mask);
 309         if (err)
 310                 goto err_free_inst;
 311
 312         alg = crypto_aead_spawn_alg(spawn);
 313
 314         err = -EINVAL;
 315         if (!alg->cra_aead.ivsize)
 316                 goto err_drop_alg;
 317
 318         /*
 319          * This is only true if we're constructing an algorithm with its
 320          * default IV generator.  For the default generator we elide the
 321          * template name and double-check the IV generator.
 322          */
 323         if (algt->mask & CRYPTO_ALG_GENIV) {
 324                 if (strcmp(tmpl->name, alg->cra_aead.geniv))
 325                         goto err_drop_alg;
 326
 327                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 328                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 329                        CRYPTO_MAX_ALG_NAME);
 330         } else {
 331                 err = -ENAMETOOLONG;
 332                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 333                              "%s(%s)", tmpl->name, alg->cra_name) >=
 334                     CRYPTO_MAX_ALG_NAME)
 335                         goto err_drop_alg;
 336                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 337                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 338                     CRYPTO_MAX_ALG_NAME)
 339                         goto err_drop_alg;
 340         }
 341
 342         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
 343         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 344         inst->alg.cra_priority = alg->cra_priority;
 345         inst->alg.cra_blocksize = alg->cra_blocksize;
 346         inst->alg.cra_alignmask = alg->cra_alignmask;
 347         inst->alg.cra_type = &crypto_aead_type;
 348
 349         inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
 350         inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
 351         inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
 352
 353         inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
 354         inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
 355         inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
 356         inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
 357
 358 out:
 359         return inst;
 360
 361 err_drop_alg:
 362         crypto_drop_aead(spawn);
 363 err_free_inst:
 364         kfree(inst);
 365         inst = ERR_PTR(err);
 366         goto out;
 367 }
 368 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 369
 370 void aead_geniv_free(struct crypto_instance *inst)
 371 {
 372         crypto_drop_aead(crypto_instance_ctx(inst));
 373         kfree(inst);
 374 }
 375 EXPORT_SYMBOL_GPL(aead_geniv_free);
 376
 377 int aead_geniv_init(struct crypto_tfm *tfm)
 378 {
 379         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 380         struct crypto_aead *aead;
 381
 382         aead = crypto_spawn_aead(crypto_instance_ctx(inst));
 383         if (IS_ERR(aead))
 384                 return PTR_ERR(aead);
 385
 386         tfm->crt_aead.base = aead;
 387         tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
 388
 389         return 0;
 390 }
 391 EXPORT_SYMBOL_GPL(aead_geniv_init);
 392
 393 void aead_geniv_exit(struct crypto_tfm *tfm)
 394 {
 395         crypto_free_aead(tfm->crt_aead.base);
 396 }
 397 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 398
 399 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
 400 {
 401         struct rtattr *tb[3];
 402         struct {
 403                 struct rtattr attr;
 404                 struct crypto_attr_type data;
 405         } ptype;
 406         struct {
 407                 struct rtattr attr;
 408                 struct crypto_attr_alg data;
 409         } palg;
 410         struct crypto_template *tmpl;
 411         struct crypto_instance *inst;
 412         struct crypto_alg *larval;
 413         const char *geniv;
 414         int err;
 415
 416         larval = crypto_larval_lookup(alg->cra_driver_name,
 417                                       CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
 418                                       CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 419         err = PTR_ERR(larval);
 420         if (IS_ERR(larval))
 421                 goto out;
 422
 423         err = -EAGAIN;
 424         if (!crypto_is_larval(larval))
 425                 goto drop_larval;
 426
 427         ptype.attr.rta_len = sizeof(ptype);
 428         ptype.attr.rta_type = CRYPTOA_TYPE;
 429         ptype.data.type = type | CRYPTO_ALG_GENIV;
 430         /* GENIV tells the template that we're making a default geniv. */
 431         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 432         tb[0] = &ptype.attr;
 433
 434         palg.attr.rta_len = sizeof(palg);
 435         palg.attr.rta_type = CRYPTOA_ALG;
 436         /* Must use the exact name to locate ourselves. */
 437         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 438         tb[1] = &palg.attr;
 439
 440         tb[2] = NULL;
 441
 442         geniv = alg->cra_aead.geniv;
 443
 444         tmpl = crypto_lookup_template(geniv);
 445         err = -ENOENT;
 446         if (!tmpl)
 447                 goto kill_larval;
 448
 449         inst = tmpl->alloc(tb);
 450         err = PTR_ERR(inst);
 451         if (IS_ERR(inst))
 452                 goto put_tmpl;
 453
 454         if ((err = crypto_register_instance(tmpl, inst))) {
 455                 tmpl->free(inst);
 456                 goto put_tmpl;
 457         }
 458
 459         /* Redo the lookup to use the instance we just registered. */
 460         err = -EAGAIN;
 461
 462 put_tmpl:
 463         crypto_tmpl_put(tmpl);
 464 kill_larval:
 465         crypto_larval_kill(larval);
 466 drop_larval:
 467         crypto_mod_put(larval);
 468 out:
 469         crypto_mod_put(alg);
 470         return err;
 471 }
 472
 473 static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
 474                                              u32 mask)
 475 {
 476         struct crypto_alg *alg;
 477
 478         alg = crypto_alg_mod_lookup(name, type, mask);
 479         if (IS_ERR(alg))
 480                 return alg;
 481
 482         if (alg->cra_type == &crypto_aead_type)
 483                 return alg;
 484
 485         if (!alg->cra_aead.ivsize)
 486                 return alg;
 487
 488         crypto_mod_put(alg);
 489         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 490                                     mask & ~CRYPTO_ALG_TESTED);
 491         if (IS_ERR(alg))
 492                 return alg;
 493
 494         if (alg->cra_type == &crypto_aead_type) {
 495                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 496                         crypto_mod_put(alg);
 497                         alg = ERR_PTR(-ENOENT);
 498                 }
 499                 return alg;
 500         }
 501
 502         BUG_ON(!alg->cra_aead.ivsize);
 503
 504         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 505 }
 506
 507 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 508                      u32 type, u32 mask)
 509 {
 510         struct crypto_alg *alg;
 511         int err;
 512
 513         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 514         type |= CRYPTO_ALG_TYPE_AEAD;
 515         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 516         mask |= CRYPTO_ALG_TYPE_MASK;
 517
 518         alg = crypto_lookup_aead(name, type, mask);
 519         if (IS_ERR(alg))
 520                 return PTR_ERR(alg);
 521
 522         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 523         crypto_mod_put(alg);
 524         return err;
 525 }
 526 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 527
 528 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 529 {
 530         struct crypto_tfm *tfm;
 531         int err;
 532
 533         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 534         type |= CRYPTO_ALG_TYPE_AEAD;
 535         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 536         mask |= CRYPTO_ALG_TYPE_MASK;
 537
 538         for (;;) {
 539                 struct crypto_alg *alg;
 540
 541                 alg = crypto_lookup_aead(alg_name, type, mask);
 542                 if (IS_ERR(alg)) {
 543                         err = PTR_ERR(alg);
 544                         goto err;
 545                 }
 546
 547                 tfm = __crypto_alloc_tfm(alg, type, mask);
 548                 if (!IS_ERR(tfm))
 549                         return __crypto_aead_cast(tfm);
 550
 551                 crypto_mod_put(alg);
 552                 err = PTR_ERR(tfm);
 553
 554 err:
 555                 if (err != -EAGAIN)
 556                         break;
 557                 if (signal_pending(current)) {
 558                         err = -EINTR;
 559                         break;
 560                 }
 561         }
 562
 563         return ERR_PTR(err);
 564 }
 565 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 566
 567 MODULE_LICENSE("GPL");
 568 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");