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 aead_null_givencrypt(struct aead_givcrypt_request *req);
  30 static int aead_null_givdecrypt(struct aead_givcrypt_request *req);
  31
  32 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  33                             unsigned int keylen)
  34 {
  35         struct aead_alg *aead = crypto_aead_alg(tfm);
  36         unsigned long alignmask = crypto_aead_alignmask(tfm);
  37         int ret;
  38         u8 *buffer, *alignbuffer;
  39         unsigned long absize;
  40
  41         absize = keylen + alignmask;
  42         buffer = kmalloc(absize, GFP_ATOMIC);
  43         if (!buffer)
  44                 return -ENOMEM;
  45
  46         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  47         memcpy(alignbuffer, key, keylen);
  48         ret = aead->setkey(tfm, alignbuffer, keylen);
  49         memset(alignbuffer, 0, keylen);
  50         kfree(buffer);
  51         return ret;
  52 }
  53
  54 int crypto_aead_setkey(struct crypto_aead *tfm,
  55                        const u8 *key, unsigned int keylen)
  56 {
  57         struct aead_alg *aead = crypto_aead_alg(tfm);
  58         unsigned long alignmask = crypto_aead_alignmask(tfm);
  59
  60         tfm = tfm->child;
  61
  62         if ((unsigned long)key & alignmask)
  63                 return setkey_unaligned(tfm, key, keylen);
  64
  65         return aead->setkey(tfm, key, keylen);
  66 }
  67 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  68
  69 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  70 {
  71         int err;
  72
  73         if (authsize > crypto_aead_alg(tfm)->maxauthsize)
  74                 return -EINVAL;
  75
  76         if (crypto_aead_alg(tfm)->setauthsize) {
  77                 err = crypto_aead_alg(tfm)->setauthsize(tfm->child, authsize);
  78                 if (err)
  79                         return err;
  80         }
  81
  82         tfm->child->authsize = authsize;
  83         tfm->authsize = authsize;
  84         return 0;
  85 }
  86 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  87
  88 static int no_givcrypt(struct aead_givcrypt_request *req)
  89 {
  90         return -ENOSYS;
  91 }
  92
  93 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  94 {
  95         struct aead_alg *alg = &tfm->__crt_alg->cra_aead;
  96         struct crypto_aead *crt = __crypto_aead_cast(tfm);
  97
  98         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
  99                 return -EINVAL;
 100
 101         crt->encrypt = alg->encrypt;
 102         crt->decrypt = alg->decrypt;
 103         if (alg->ivsize) {
 104                 crt->givencrypt = alg->givencrypt ?: no_givcrypt;
 105                 crt->givdecrypt = alg->givdecrypt ?: no_givcrypt;
 106         } else {
 107                 crt->givencrypt = aead_null_givencrypt;
 108                 crt->givdecrypt = aead_null_givdecrypt;
 109         }
 110         crt->child = __crypto_aead_cast(tfm);
 111         crt->ivsize = alg->ivsize;
 112         crt->authsize = alg->maxauthsize;
 113
 114         return 0;
 115 }
 116
 117 #ifdef CONFIG_NET
 118 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 119 {
 120         struct crypto_report_aead raead;
 121         struct aead_alg *aead = &alg->cra_aead;
 122
 123         strncpy(raead.type, "aead", sizeof(raead.type));
 124         strncpy(raead.geniv, aead->geniv ?: "<built-in>", sizeof(raead.geniv));
 125
 126         raead.blocksize = alg->cra_blocksize;
 127         raead.maxauthsize = aead->maxauthsize;
 128         raead.ivsize = aead->ivsize;
 129
 130         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 131                     sizeof(struct crypto_report_aead), &raead))
 132                 goto nla_put_failure;
 133         return 0;
 134
 135 nla_put_failure:
 136         return -EMSGSIZE;
 137 }
 138 #else
 139 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 140 {
 141         return -ENOSYS;
 142 }
 143 #endif
 144
 145 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 146         __attribute__ ((unused));
 147 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 148 {
 149         struct aead_alg *aead = &alg->cra_aead;
 150
 151         seq_printf(m, "type         : aead\n");
 152         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 153                                              "yes" : "no");
 154         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 155         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 156         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 157         seq_printf(m, "geniv        : %s\n", aead->geniv ?: "<built-in>");
 158 }
 159
 160 const struct crypto_type crypto_aead_type = {
 161         .extsize = crypto_alg_extsize,
 162         .init_tfm = crypto_aead_init_tfm,
 163 #ifdef CONFIG_PROC_FS
 164         .show = crypto_aead_show,
 165 #endif
 166         .report = crypto_aead_report,
 167         .lookup = crypto_lookup_aead,
 168         .maskclear = ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV),
 169         .maskset = CRYPTO_ALG_TYPE_MASK,
 170         .type = CRYPTO_ALG_TYPE_AEAD,
 171         .tfmsize = offsetof(struct crypto_aead, base),
 172 };
 173 EXPORT_SYMBOL_GPL(crypto_aead_type);
 174
 175 static int aead_null_givencrypt(struct aead_givcrypt_request *req)
 176 {
 177         return crypto_aead_encrypt(&req->areq);
 178 }
 179
 180 static int aead_null_givdecrypt(struct aead_givcrypt_request *req)
 181 {
 182         return crypto_aead_decrypt(&req->areq);
 183 }
 184
 185 #ifdef CONFIG_NET
 186 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 187 {
 188         struct crypto_report_aead raead;
 189         struct aead_alg *aead = &alg->cra_aead;
 190
 191         strncpy(raead.type, "nivaead", sizeof(raead.type));
 192         strncpy(raead.geniv, aead->geniv, sizeof(raead.geniv));
 193
 194         raead.blocksize = alg->cra_blocksize;
 195         raead.maxauthsize = aead->maxauthsize;
 196         raead.ivsize = aead->ivsize;
 197
 198         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 199                     sizeof(struct crypto_report_aead), &raead))
 200                 goto nla_put_failure;
 201         return 0;
 202
 203 nla_put_failure:
 204         return -EMSGSIZE;
 205 }
 206 #else
 207 static int crypto_nivaead_report(struct sk_buff *skb, struct crypto_alg *alg)
 208 {
 209         return -ENOSYS;
 210 }
 211 #endif
 212
 213
 214 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 215         __attribute__ ((unused));
 216 static void crypto_nivaead_show(struct seq_file *m, struct crypto_alg *alg)
 217 {
 218         struct aead_alg *aead = &alg->cra_aead;
 219
 220         seq_printf(m, "type         : nivaead\n");
 221         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 222                                              "yes" : "no");
 223         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 224         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 225         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 226         seq_printf(m, "geniv        : %s\n", aead->geniv);
 227 }
 228
 229 const struct crypto_type crypto_nivaead_type = {
 230         .extsize = crypto_alg_extsize,
 231         .init_tfm = crypto_aead_init_tfm,
 232 #ifdef CONFIG_PROC_FS
 233         .show = crypto_nivaead_show,
 234 #endif
 235         .report = crypto_nivaead_report,
 236         .maskclear = ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV),
 237         .maskset = CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV,
 238         .type = CRYPTO_ALG_TYPE_AEAD,
 239         .tfmsize = offsetof(struct crypto_aead, base),
 240 };
 241 EXPORT_SYMBOL_GPL(crypto_nivaead_type);
 242
 243 static int crypto_grab_nivaead(struct crypto_aead_spawn *spawn,
 244                                const char *name, u32 type, u32 mask)
 245 {
 246         spawn->base.frontend = &crypto_nivaead_type;
 247         return crypto_grab_spawn(&spawn->base, name, type, mask);
 248 }
 249
 250 struct crypto_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 251                                          struct rtattr **tb, u32 type,
 252                                          u32 mask)
 253 {
 254         const char *name;
 255         struct crypto_aead_spawn *spawn;
 256         struct crypto_attr_type *algt;
 257         struct crypto_instance *inst;
 258         struct crypto_alg *alg;
 259         int err;
 260
 261         algt = crypto_get_attr_type(tb);
 262         if (IS_ERR(algt))
 263                 return ERR_CAST(algt);
 264
 265         if ((algt->type ^ (CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV)) &
 266             algt->mask)
 267                 return ERR_PTR(-EINVAL);
 268
 269         name = crypto_attr_alg_name(tb[1]);
 270         if (IS_ERR(name))
 271                 return ERR_CAST(name);
 272
 273         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 274         if (!inst)
 275                 return ERR_PTR(-ENOMEM);
 276
 277         spawn = crypto_instance_ctx(inst);
 278
 279         /* Ignore async algorithms if necessary. */
 280         mask |= crypto_requires_sync(algt->type, algt->mask);
 281
 282         crypto_set_aead_spawn(spawn, inst);
 283         err = crypto_grab_nivaead(spawn, name, type, mask);
 284         if (err)
 285                 goto err_free_inst;
 286
 287         alg = crypto_aead_spawn_alg(spawn);
 288
 289         err = -EINVAL;
 290         if (!alg->cra_aead.ivsize)
 291                 goto err_drop_alg;
 292
 293         /*
 294          * This is only true if we're constructing an algorithm with its
 295          * default IV generator.  For the default generator we elide the
 296          * template name and double-check the IV generator.
 297          */
 298         if (algt->mask & CRYPTO_ALG_GENIV) {
 299                 if (strcmp(tmpl->name, alg->cra_aead.geniv))
 300                         goto err_drop_alg;
 301
 302                 memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
 303                 memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
 304                        CRYPTO_MAX_ALG_NAME);
 305         } else {
 306                 err = -ENAMETOOLONG;
 307                 if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
 308                              "%s(%s)", tmpl->name, alg->cra_name) >=
 309                     CRYPTO_MAX_ALG_NAME)
 310                         goto err_drop_alg;
 311                 if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 312                              "%s(%s)", tmpl->name, alg->cra_driver_name) >=
 313                     CRYPTO_MAX_ALG_NAME)
 314                         goto err_drop_alg;
 315         }
 316
 317         inst->alg.cra_flags = CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV;
 318         inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
 319         inst->alg.cra_priority = alg->cra_priority;
 320         inst->alg.cra_blocksize = alg->cra_blocksize;
 321         inst->alg.cra_alignmask = alg->cra_alignmask;
 322         inst->alg.cra_type = &crypto_aead_type;
 323
 324         inst->alg.cra_aead.ivsize = alg->cra_aead.ivsize;
 325         inst->alg.cra_aead.maxauthsize = alg->cra_aead.maxauthsize;
 326         inst->alg.cra_aead.geniv = alg->cra_aead.geniv;
 327
 328         inst->alg.cra_aead.setkey = alg->cra_aead.setkey;
 329         inst->alg.cra_aead.setauthsize = alg->cra_aead.setauthsize;
 330         inst->alg.cra_aead.encrypt = alg->cra_aead.encrypt;
 331         inst->alg.cra_aead.decrypt = alg->cra_aead.decrypt;
 332
 333 out:
 334         return inst;
 335
 336 err_drop_alg:
 337         crypto_drop_aead(spawn);
 338 err_free_inst:
 339         kfree(inst);
 340         inst = ERR_PTR(err);
 341         goto out;
 342 }
 343 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 344
 345 void aead_geniv_free(struct crypto_instance *inst)
 346 {
 347         crypto_drop_aead(crypto_instance_ctx(inst));
 348         kfree(inst);
 349 }
 350 EXPORT_SYMBOL_GPL(aead_geniv_free);
 351
 352 int aead_geniv_init(struct crypto_tfm *tfm)
 353 {
 354         struct crypto_instance *inst = (void *)tfm->__crt_alg;
 355         struct crypto_aead *child;
 356         struct crypto_aead *aead;
 357
 358         aead = __crypto_aead_cast(tfm);
 359
 360         child = crypto_spawn_aead(crypto_instance_ctx(inst));
 361         if (IS_ERR(child))
 362                 return PTR_ERR(child);
 363
 364         aead->child = child;
 365         aead->reqsize += crypto_aead_reqsize(child);
 366
 367         return 0;
 368 }
 369 EXPORT_SYMBOL_GPL(aead_geniv_init);
 370
 371 void aead_geniv_exit(struct crypto_tfm *tfm)
 372 {
 373         crypto_free_aead(__crypto_aead_cast(tfm)->child);
 374 }
 375 EXPORT_SYMBOL_GPL(aead_geniv_exit);
 376
 377 static int crypto_nivaead_default(struct crypto_alg *alg, u32 type, u32 mask)
 378 {
 379         struct rtattr *tb[3];
 380         struct {
 381                 struct rtattr attr;
 382                 struct crypto_attr_type data;
 383         } ptype;
 384         struct {
 385                 struct rtattr attr;
 386                 struct crypto_attr_alg data;
 387         } palg;
 388         struct crypto_template *tmpl;
 389         struct crypto_instance *inst;
 390         struct crypto_alg *larval;
 391         const char *geniv;
 392         int err;
 393
 394         larval = crypto_larval_lookup(alg->cra_driver_name,
 395                                       CRYPTO_ALG_TYPE_AEAD | CRYPTO_ALG_GENIV,
 396                                       CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
 397         err = PTR_ERR(larval);
 398         if (IS_ERR(larval))
 399                 goto out;
 400
 401         err = -EAGAIN;
 402         if (!crypto_is_larval(larval))
 403                 goto drop_larval;
 404
 405         ptype.attr.rta_len = sizeof(ptype);
 406         ptype.attr.rta_type = CRYPTOA_TYPE;
 407         ptype.data.type = type | CRYPTO_ALG_GENIV;
 408         /* GENIV tells the template that we're making a default geniv. */
 409         ptype.data.mask = mask | CRYPTO_ALG_GENIV;
 410         tb[0] = &ptype.attr;
 411
 412         palg.attr.rta_len = sizeof(palg);
 413         palg.attr.rta_type = CRYPTOA_ALG;
 414         /* Must use the exact name to locate ourselves. */
 415         memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
 416         tb[1] = &palg.attr;
 417
 418         tb[2] = NULL;
 419
 420         geniv = alg->cra_aead.geniv;
 421
 422         tmpl = crypto_lookup_template(geniv);
 423         err = -ENOENT;
 424         if (!tmpl)
 425                 goto kill_larval;
 426
 427         inst = tmpl->alloc(tb);
 428         err = PTR_ERR(inst);
 429         if (IS_ERR(inst))
 430                 goto put_tmpl;
 431
 432         err = crypto_register_instance(tmpl, inst);
 433         if (err) {
 434                 tmpl->free(inst);
 435                 goto put_tmpl;
 436         }
 437
 438         /* Redo the lookup to use the instance we just registered. */
 439         err = -EAGAIN;
 440
 441 put_tmpl:
 442         crypto_tmpl_put(tmpl);
 443 kill_larval:
 444         crypto_larval_kill(larval);
 445 drop_larval:
 446         crypto_mod_put(larval);
 447 out:
 448         crypto_mod_put(alg);
 449         return err;
 450 }
 451
 452 struct crypto_alg *crypto_lookup_aead(const char *name, u32 type, u32 mask)
 453 {
 454         struct crypto_alg *alg;
 455
 456         alg = crypto_alg_mod_lookup(name, type, mask);
 457         if (IS_ERR(alg))
 458                 return alg;
 459
 460         if (alg->cra_type == &crypto_aead_type)
 461                 return alg;
 462
 463         if (!alg->cra_aead.ivsize)
 464                 return alg;
 465
 466         crypto_mod_put(alg);
 467         alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
 468                                     mask & ~CRYPTO_ALG_TESTED);
 469         if (IS_ERR(alg))
 470                 return alg;
 471
 472         if (alg->cra_type == &crypto_aead_type) {
 473                 if (~alg->cra_flags & (type ^ ~mask) & CRYPTO_ALG_TESTED) {
 474                         crypto_mod_put(alg);
 475                         alg = ERR_PTR(-ENOENT);
 476                 }
 477                 return alg;
 478         }
 479
 480         BUG_ON(!alg->cra_aead.ivsize);
 481
 482         return ERR_PTR(crypto_nivaead_default(alg, type, mask));
 483 }
 484 EXPORT_SYMBOL_GPL(crypto_lookup_aead);
 485
 486 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 487                      u32 type, u32 mask)
 488 {
 489         spawn->base.frontend = &crypto_aead_type;
 490         return crypto_grab_spawn(&spawn->base, name, type, mask);
 491 }
 492 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 493
 494 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 495 {
 496         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 497 }
 498 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 499
 500 MODULE_LICENSE("GPL");
 501 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");