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 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 115 {
 116         struct crypto_report_aead raead;
 117         struct aead_alg *aead = &alg->cra_aead;
 118
 119         snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "aead");
 120         snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s",
 121                  aead->geniv ?: "<built-in>");
 122
 123         raead.blocksize = alg->cra_blocksize;
 124         raead.maxauthsize = aead->maxauthsize;
 125         raead.ivsize = aead->ivsize;
 126
 127         NLA_PUT(skb, CRYPTOCFGA_REPORT_AEAD,
 128                 sizeof(struct crypto_report_aead), &raead);
 129
 130         return 0;
 131
 132 nla_put_failure:
 133         return -EMSGSIZE;
 134 }
 135
 136 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 137         __attribute__ ((unused));
 138 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 139 {
 140         struct aead_alg *aead = &alg->cra_aead;
 141
 142         seq_printf(m, "type         : aead\n");
 143         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 144                                              "yes" : "no");
 145         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 146         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 147         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 148         seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
 149 }
 150
 151 const struct crypto_type crypto_aead_type = {
 152         .ctxsize = crypto_aead_ctxsize,
 153         .init = crypto_init_aead_ops,
 154 #ifdef CONFIG_PROC_FS
 155         .show = crypto_aead_show,
 156 #endif
 157         .report = crypto_aead_report,
 158 };
 159 EXPORT_SYMBOL_GPL(crypto_aead_type);
 160
 161 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
 162 {
 163         return crypto_aead_encrypt(&req->areq);
 164 }
 165
 166 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
 167 {
 168         return crypto_aead_decrypt(&req->areq);
 169 }
 170
 171 static int crypto_init_nivaead_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
 172 {
 173         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
 174         struct aead_tfm *crt = &tfm->crt_aead;
 175
 176         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
 177                 return -EINVAL;
 178
 179         crt->setkey = setkey;
 180         crt->encrypt = alg->encrypt;
 181         crt->decrypt = alg->decrypt;
 182         if (!alg->ivsize) {
 183                 crt->givencrypt = aead_null_givencrypt;
 184                 crt->givdecrypt = aead_null_givdecrypt;
 185         }
 186         crt->base = __crypto_aead_cast(tfm);
 187         crt->ivsize = alg->ivsize;
 188         crt->authsize = alg->maxauthsize;
 189
 190         return 0;
 191 }
 192
 193 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 194 {
 195         struct crypto_report_aead raead;
 196         struct aead_alg *aead = &alg->cra_aead;
 197
 198         snprintf(raead.type, CRYPTO_MAX_ALG_NAME, "%s", "nivaead");
 199         snprintf(raead.geniv, CRYPTO_MAX_ALG_NAME, "%s", aead->geniv);
 200
 201         raead.blocksize = alg->cra_blocksize;
 202         raead.maxauthsize = aead->maxauthsize;
 203         raead.ivsize = aead->ivsize;
 204
 205         NLA_PUT(skb, CRYPTOCFGA_REPORT_AEAD,
 206                 sizeof(struct crypto_report_aead), &raead);
 207
 208         return 0;
 209
 210 nla_put_failure:
 211         return -EMSGSIZE;
 212 }
 213
 214
 215 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 216         __attribute__ ((unused));
 217 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 218 {
 219         struct aead_alg *aead = &alg->cra_aead;
 220
 221         seq_printf(m, "type         : nivaead\n");
 222         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 223                                              "yes" : "no");
 224         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 225         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 226         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 227         seq_printf(m, "geniv        : %s\n", aead->geniv);
 228 }
 229
 230 const struct crypto_type crypto_nivaead_type = {
 231         .ctxsize = crypto_aead_ctxsize,
 232         .init = crypto_init_nivaead_ops,
 233 #ifdef CONFIG_PROC_FS
 234         .show = crypto_nivaead_show,
 235 #endif
 236         .report = crypto_nivaead_report,
 237 };
 238 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
 239
 240 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
 241                                const char *name, u32 type, u32 mask)
 242 {
 243         struct crypto_alg *alg;
 244         int err;
 245
 246         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 247         type |= CRYPTO_ALG_TYPE_AEAD;
 248         mask |= CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV;
 249
 250         alg = crypto_alg_mod_lookup(name, type, mask);
 251         if (IS_ERR(alg))
 252                 return PTR_ERR(alg);
 253
 254         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 255         crypto_mod_put(alg);
 256         return err;
 257 }
 258
 259 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 260                                          struct rtattr **tb, u32 type,
 261                                          u32 mask)
 262 {
 263         const char *name;
 264         struct crypto_aead_spawn *spawn;
 265         struct crypto_attr_type *algt;
 266         struct crypto_instance *inst;
 267         struct crypto_alg *alg;
 268         int err;
 269
 270         algt = crypto_get_attr_type(tb);
 271         err = PTR_ERR(algt);
 272         if (IS_ERR(algt))
 273                 return ERR_PTR(err);
 274
 275         if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
 276             algt->mask)
 277                 return ERR_PTR(-EINVAL);
 278
 279         name = crypto_attr_alg_name(tb[1]);
 280         err = PTR_ERR(name);
 281         if (IS_ERR(name))
 282                 return ERR_PTR(err);
 283
 284         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 285         if (!inst)
 286                 return ERR_PTR(-ENOMEM);
 287
 288         spawn = crypto_instance_ctx(inst);
 289
 290         /* Ignore async algorithms if necessary. */
 291         mask |= crypto_requires_sync(algt->type, algt->mask);
 292
 293         crypto_set_aead_spawn(spawn, inst);
 294         err = crypto_grab_nivaead(spawn, name, type, mask);
 295         if (err)
 296                 goto err_free_inst;
 297
 298         alg = crypto_aead_spawn_alg(spawn);
 299
 300         err = -EINVAL;
 301         if (!alg->cra_aead.ivsize)
 302                 goto err_drop_alg;
 303
 304         /*
 305          * This is only true if we're constructing an algorithm with its
 306          * default IV generator.  For the default generator we elide the
 307          * template name and double-check the IV generator.
 308          */
 309         if (algt->mask & CRYPTO_ALG_GENIV) {
 310                 if (strcmp(tmpl->name, alg->cra_aead.geniv))
 311                         goto err_drop_alg;
 312
 313                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 314                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 315                        CRYPTO_MAX_ALG_NAME);
 316         } else {
 317                 err = -ENAMETOOLONG;
 318                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 319                              "%s(%s)", tmpl->name, alg->cra_name) >=
 320                     CRYPTO_MAX_ALG_NAME)
 321                         goto err_drop_alg;
 322                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 323                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 324                     CRYPTO_MAX_ALG_NAME)
 325                         goto err_drop_alg;
 326         }
 327
 328         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
 329         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 330         inst->alg.cra_priority = alg->cra_priority;
 331         inst->alg.cra_blocksize = alg->cra_blocksize;
 332         inst->alg.cra_alignmask = alg->cra_alignmask;
 333         inst->alg.cra_type = &crypto_aead_type;
 334
 335         inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
 336         inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
 337         inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
 338
 339         inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
 340         inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
 341         inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
 342         inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
 343
 344 out:
 345         return inst;
 346
 347 err_drop_alg:
 348         crypto_drop_aead(spawn);
 349 err_free_inst:
 350         kfree(inst);
 351         inst = ERR_PTR(err);
 352         goto out;
 353 }
 354 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 355
 356 void aead_geniv_free(struct crypto_instance *inst)
 357 {
 358         crypto_drop_aead(crypto_instance_ctx(inst));
 359         kfree(inst);
 360 }
 361 EXPORT_SYMBOL_GPL(aead_geniv_free);
 362
 363 int aead_geniv_init(struct crypto_tfm *tfm)
 364 {
 365         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 366         struct crypto_aead *aead;
 367
 368         aead = crypto_spawn_aead(crypto_instance_ctx(inst));
 369         if (IS_ERR(aead))
 370                 return PTR_ERR(aead);
 371
 372         tfm->crt_aead.base = aead;
 373         tfm->crt_aead.reqsize += crypto_aead_reqsize(aead);
 374
 375         return 0;
 376 }
 377 EXPORT_SYMBOL_GPL(aead_geniv_init);
 378
 379 void aead_geniv_exit(struct crypto_tfm *tfm)
 380 {
 381         crypto_free_aead(tfm->crt_aead.base);
 382 }
 383 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 384
 385 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
 386 {
 387         struct rtattr *tb[3];
 388         struct {
 389                 struct rtattr attr;
 390                 struct crypto_attr_type data;
 391         } ptype;
 392         struct {
 393                 struct rtattr attr;
 394                 struct crypto_attr_alg data;
 395         } palg;
 396         struct crypto_template *tmpl;
 397         struct crypto_instance *inst;
 398         struct crypto_alg *larval;
 399         const char *geniv;
 400         int err;
 401
 402         larval = crypto_larval_lookup(alg->cra_driver_name,
 403                                       CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
 404                                       CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 405         err = PTR_ERR(larval);
 406         if (IS_ERR(larval))
 407                 goto out;
 408
 409         err = -EAGAIN;
 410         if (!crypto_is_larval(larval))
 411                 goto drop_larval;
 412
 413         ptype.attr.rta_len = sizeof(ptype);
 414         ptype.attr.rta_type = CRYPTOA_TYPE;
 415         ptype.data.type = type | CRYPTO_ALG_GENIV;
 416         /* GENIV tells the template that we're making a default geniv. */
 417         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 418         tb[0] = &ptype.attr;
 419
 420         palg.attr.rta_len = sizeof(palg);
 421         palg.attr.rta_type = CRYPTOA_ALG;
 422         /* Must use the exact name to locate ourselves. */
 423         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 424         tb[1] = &palg.attr;
 425
 426         tb[2] = NULL;
 427
 428         geniv = alg->cra_aead.geniv;
 429
 430         tmpl = crypto_lookup_template(geniv);
 431         err = -ENOENT;
 432         if (!tmpl)
 433                 goto kill_larval;
 434
 435         inst = tmpl->alloc(tb);
 436         err = PTR_ERR(inst);
 437         if (IS_ERR(inst))
 438                 goto put_tmpl;
 439
 440         if ((err = crypto_register_instance(tmpl, inst))) {
 441                 tmpl->free(inst);
 442                 goto put_tmpl;
 443         }
 444
 445         /* Redo the lookup to use the instance we just registered. */
 446         err = -EAGAIN;
 447
 448 put_tmpl:
 449         crypto_tmpl_put(tmpl);
 450 kill_larval:
 451         crypto_larval_kill(larval);
 452 drop_larval:
 453         crypto_mod_put(larval);
 454 out:
 455         crypto_mod_put(alg);
 456         return err;
 457 }
 458
 459 static struct crypto_alg *crypto_lookup_aead(const char *name, u32 type,
 460                                              u32 mask)
 461 {
 462         struct crypto_alg *alg;
 463
 464         alg = crypto_alg_mod_lookup(name, type, mask);
 465         if (IS_ERR(alg))
 466                 return alg;
 467
 468         if (alg->cra_type == &crypto_aead_type)
 469                 return alg;
 470
 471         if (!alg->cra_aead.ivsize)
 472                 return alg;
 473
 474         crypto_mod_put(alg);
 475         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 476                                     mask & ~CRYPTO_ALG_TESTED);
 477         if (IS_ERR(alg))
 478                 return alg;
 479
 480         if (alg->cra_type == &crypto_aead_type) {
 481                 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
 482                         crypto_mod_put(alg);
 483                         alg = ERR_PTR(-ENOENT);
 484                 }
 485                 return alg;
 486         }
 487
 488         BUG_ON(!alg->cra_aead.ivsize);
 489
 490         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 491 }
 492
 493 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 494                      u32 type, u32 mask)
 495 {
 496         struct crypto_alg *alg;
 497         int err;
 498
 499         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 500         type |= CRYPTO_ALG_TYPE_AEAD;
 501         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 502         mask |= CRYPTO_ALG_TYPE_MASK;
 503
 504         alg = crypto_lookup_aead(name, type, mask);
 505         if (IS_ERR(alg))
 506                 return PTR_ERR(alg);
 507
 508         err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
 509         crypto_mod_put(alg);
 510         return err;
 511 }
 512 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 513
 514 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 515 {
 516         struct crypto_tfm *tfm;
 517         int err;
 518
 519         type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 520         type |= CRYPTO_ALG_TYPE_AEAD;
 521         mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 522         mask |= CRYPTO_ALG_TYPE_MASK;
 523
 524         for (;;) {
 525                 struct crypto_alg *alg;
 526
 527                 alg = crypto_lookup_aead(alg_name, type, mask);
 528                 if (IS_ERR(alg)) {
 529                         err = PTR_ERR(alg);
 530                         goto err;
 531                 }
 532
 533                 tfm = __crypto_alloc_tfm(alg, type, mask);
 534                 if (!IS_ERR(tfm))
 535                         return __crypto_aead_cast(tfm);
 536
 537                 crypto_mod_put(alg);
 538                 err = PTR_ERR(tfm);
 539
 540 err:
 541                 if (err != -EAGAIN)
 542                         break;
 543                 if (signal_pending(current)) {
 544                         err = -EINTR;
 545                         break;
 546                 }
 547         }
 548
 549         return ERR_PTR(err);
 550 }
 551 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 552
 553 MODULE_LICENSE("GPL");
 554 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");