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) 2007-2015 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
  32 static 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
  53 int crypto_aead_setkey(struct crypto_aead *tfm,
  54                        const u8 *key, unsigned int keylen)
  55 {
  56         unsigned long alignmask = crypto_aead_alignmask(tfm);
  57
  58         if ((unsigned long)key & alignmask)
  59                 return setkey_unaligned(tfm, key, keylen);
  60
  61         return crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
  62 }
  63 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  64
  65 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  66 {
  67         int err;
  68
  69         if (authsize > crypto_aead_maxauthsize(tfm))
  70                 return -EINVAL;
  71
  72         if (crypto_aead_alg(tfm)->setauthsize) {
  73                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  74                 if (err)
  75                         return err;
  76         }
  77
  78         tfm->authsize = authsize;
  79         return 0;
  80 }
  81 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  82
  83 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
  84 {
  85         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  86         struct aead_alg *alg = crypto_aead_alg(aead);
  87
  88         alg->exit(aead);
  89 }
  90
  91 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  92 {
  93         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  94         struct aead_alg *alg = crypto_aead_alg(aead);
  95
  96         aead->authsize = alg->maxauthsize;
  97
  98         if (alg->exit)
  99                 aead->base.exit = crypto_aead_exit_tfm;
 100
 101         if (alg->init)
 102                 return alg->init(aead);
 103
 104         return 0;
 105 }
 106
 107 #ifdef CONFIG_NET
 108 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 109 {
 110         struct crypto_report_aead raead;
 111         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 112
 113         strncpy(raead.type, "aead", sizeof(raead.type));
 114         strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
 115
 116         raead.blocksize = alg->cra_blocksize;
 117         raead.maxauthsize = aead->maxauthsize;
 118         raead.ivsize = aead->ivsize;
 119
 120         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 121                     sizeof(struct crypto_report_aead), &raead))
 122                 goto nla_put_failure;
 123         return 0;
 124
 125 nla_put_failure:
 126         return -EMSGSIZE;
 127 }
 128 #else
 129 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 130 {
 131         return -ENOSYS;
 132 }
 133 #endif
 134
 135 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 136         __maybe_unused;
 137 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 138 {
 139         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 140
 141         seq_printf(m, "type         : aead\n");
 142         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 143                                              "yes" : "no");
 144         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 145         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 146         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 147         seq_printf(m, "geniv        : <none>\n");
 148 }
 149
 150 static void crypto_aead_free_instance(struct crypto_instance *inst)
 151 {
 152         struct aead_instance *aead = aead_instance(inst);
 153
 154         if (!aead->free) {
 155                 inst->tmpl->free(inst);
 156                 return;
 157         }
 158
 159         aead->free(aead);
 160 }
 161
 162 static const struct crypto_type crypto_aead_type = {
 163         .extsize = crypto_alg_extsize,
 164         .init_tfm = crypto_aead_init_tfm,
 165         .free = crypto_aead_free_instance,
 166 #ifdef CONFIG_PROC_FS
 167         .show = crypto_aead_show,
 168 #endif
 169         .report = crypto_aead_report,
 170         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 171         .maskset = CRYPTO_ALG_TYPE_MASK,
 172         .type = CRYPTO_ALG_TYPE_AEAD,
 173         .tfmsize = offsetof(struct crypto_aead, base),
 174 };
 175
 176 static int aead_geniv_setkey(struct crypto_aead *tfm,
 177                              const u8 *key, unsigned int keylen)
 178 {
 179         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 180
 181         return crypto_aead_setkey(ctx->child, key, keylen);
 182 }
 183
 184 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
 185                                   unsigned int authsize)
 186 {
 187         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 188
 189         return crypto_aead_setauthsize(ctx->child, authsize);
 190 }
 191
 192 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 193                                        struct rtattr **tb, u32 type, u32 mask)
 194 {
 195         const char *name;
 196         struct crypto_aead_spawn *spawn;
 197         struct crypto_attr_type *algt;
 198         struct aead_instance *inst;
 199         struct aead_alg *alg;
 200         unsigned int ivsize;
 201         unsigned int maxauthsize;
 202         int err;
 203
 204         algt = crypto_get_attr_type(tb);
 205         if (IS_ERR(algt))
 206                 return ERR_CAST(algt);
 207
 208         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 209                 return ERR_PTR(-EINVAL);
 210
 211         name = crypto_attr_alg_name(tb[1]);
 212         if (IS_ERR(name))
 213                 return ERR_CAST(name);
 214
 215         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 216         if (!inst)
 217                 return ERR_PTR(-ENOMEM);
 218
 219         spawn = aead_instance_ctx(inst);
 220
 221         /* Ignore async algorithms if necessary. */
 222         mask |= crypto_requires_sync(algt->type, algt->mask);
 223
 224         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 225         err = crypto_grab_aead(spawn, name, type, mask);
 226         if (err)
 227                 goto err_free_inst;
 228
 229         alg = crypto_spawn_aead_alg(spawn);
 230
 231         ivsize = crypto_aead_alg_ivsize(alg);
 232         maxauthsize = crypto_aead_alg_maxauthsize(alg);
 233
 234         err = -EINVAL;
 235         if (ivsize < sizeof(u64))
 236                 goto err_drop_alg;
 237
 238         err = -ENAMETOOLONG;
 239         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 240                      "%s(%s)", tmpl->name, alg->base.cra_name) >=
 241             CRYPTO_MAX_ALG_NAME)
 242                 goto err_drop_alg;
 243         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 244                      "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
 245             CRYPTO_MAX_ALG_NAME)
 246                 goto err_drop_alg;
 247
 248         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 249         inst->alg.base.cra_priority = alg->base.cra_priority;
 250         inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 251         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 252         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 253
 254         inst->alg.setkey = aead_geniv_setkey;
 255         inst->alg.setauthsize = aead_geniv_setauthsize;
 256
 257         inst->alg.ivsize = ivsize;
 258         inst->alg.maxauthsize = maxauthsize;
 259
 260 out:
 261         return inst;
 262
 263 err_drop_alg:
 264         crypto_drop_aead(spawn);
 265 err_free_inst:
 266         kfree(inst);
 267         inst = ERR_PTR(err);
 268         goto out;
 269 }
 270 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 271
 272 void aead_geniv_free(struct aead_instance *inst)
 273 {
 274         crypto_drop_aead(aead_instance_ctx(inst));
 275         kfree(inst);
 276 }
 277 EXPORT_SYMBOL_GPL(aead_geniv_free);
 278
 279 int aead_init_geniv(struct crypto_aead *aead)
 280 {
 281         struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
 282         struct aead_instance *inst = aead_alg_instance(aead);
 283         struct crypto_aead *child;
 284         int err;
 285
 286         spin_lock_init(&ctx->lock);
 287
 288         err = crypto_get_default_rng();
 289         if (err)
 290                 goto out;
 291
 292         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 293                                    crypto_aead_ivsize(aead));
 294         crypto_put_default_rng();
 295         if (err)
 296                 goto out;
 297
 298         ctx->sknull = crypto_get_default_null_skcipher2();
 299         err = PTR_ERR(ctx->sknull);
 300         if (IS_ERR(ctx->sknull))
 301                 goto out;
 302
 303         child = crypto_spawn_aead(aead_instance_ctx(inst));
 304         err = PTR_ERR(child);
 305         if (IS_ERR(child))
 306                 goto drop_null;
 307
 308         ctx->child = child;
 309         crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
 310                                       sizeof(struct aead_request));
 311
 312         err = 0;
 313
 314 out:
 315         return err;
 316
 317 drop_null:
 318         crypto_put_default_null_skcipher2();
 319         goto out;
 320 }
 321 EXPORT_SYMBOL_GPL(aead_init_geniv);
 322
 323 void aead_exit_geniv(struct crypto_aead *tfm)
 324 {
 325         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 326
 327         crypto_free_aead(ctx->child);
 328         crypto_put_default_null_skcipher2();
 329 }
 330 EXPORT_SYMBOL_GPL(aead_exit_geniv);
 331
 332 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 333                      u32 type, u32 mask)
 334 {
 335         spawn->base.frontend = &crypto_aead_type;
 336         return crypto_grab_spawn(&spawn->base, name, type, mask);
 337 }
 338 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 339
 340 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 341 {
 342         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 343 }
 344 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 345
 346 static int aead_prepare_alg(struct aead_alg *alg)
 347 {
 348         struct crypto_alg *base = &alg->base;
 349
 350         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 351             PAGE_SIZE / 8)
 352                 return -EINVAL;
 353
 354         if (!alg->chunksize)
 355                 alg->chunksize = base->cra_blocksize;
 356
 357         base->cra_type = &crypto_aead_type;
 358         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 359         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 360
 361         return 0;
 362 }
 363
 364 int crypto_register_aead(struct aead_alg *alg)
 365 {
 366         struct crypto_alg *base = &alg->base;
 367         int err;
 368
 369         err = aead_prepare_alg(alg);
 370         if (err)
 371                 return err;
 372
 373         return crypto_register_alg(base);
 374 }
 375 EXPORT_SYMBOL_GPL(crypto_register_aead);
 376
 377 void crypto_unregister_aead(struct aead_alg *alg)
 378 {
 379         crypto_unregister_alg(&alg->base);
 380 }
 381 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 382
 383 int crypto_register_aeads(struct aead_alg *algs, int count)
 384 {
 385         int i, ret;
 386
 387         for (i = 0; i < count; i++) {
 388                 ret = crypto_register_aead(&algs[i]);
 389                 if (ret)
 390                         goto err;
 391         }
 392
 393         return 0;
 394
 395 err:
 396         for (--i; i >= 0; --i)
 397                 crypto_unregister_aead(&algs[i]);
 398
 399         return ret;
 400 }
 401 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 402
 403 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 404 {
 405         int i;
 406
 407         for (i = count - 1; i >= 0; --i)
 408                 crypto_unregister_aead(&algs[i]);
 409 }
 410 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 411
 412 int aead_register_instance(struct crypto_template *tmpl,
 413                            struct aead_instance *inst)
 414 {
 415         int err;
 416
 417         err = aead_prepare_alg(&inst->alg);
 418         if (err)
 419                 return err;
 420
 421         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 422 }
 423 EXPORT_SYMBOL_GPL(aead_register_instance);
 424
 425 MODULE_LICENSE("GPL");
 426 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");