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 <net/netlink.h>
  28
  29 #include "internal.h"
  30
  31 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  32                             unsigned int keylen)
  33 {
  34         unsigned long alignmask = crypto_aead_alignmask(tfm);
  35         int ret;
  36         u8 *buffer, *alignbuffer;
  37         unsigned long absize;
  38
  39         absize = keylen + alignmask;
  40         buffer = kmalloc(absize, GFP_ATOMIC);
  41         if (!buffer)
  42                 return -ENOMEM;
  43
  44         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  45         memcpy(alignbuffer, key, keylen);
  46         ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
  47         memset(alignbuffer, 0, keylen);
  48         kfree(buffer);
  49         return ret;
  50 }
  51
  52 int crypto_aead_setkey(struct crypto_aead *tfm,
  53                        const u8 *key, unsigned int keylen)
  54 {
  55         unsigned long alignmask = crypto_aead_alignmask(tfm);
  56
  57         if ((unsigned long)key & alignmask)
  58                 return setkey_unaligned(tfm, key, keylen);
  59
  60         return crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
  61 }
  62 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  63
  64 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  65 {
  66         int err;
  67
  68         if (authsize > crypto_aead_maxauthsize(tfm))
  69                 return -EINVAL;
  70
  71         if (crypto_aead_alg(tfm)->setauthsize) {
  72                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  73                 if (err)
  74                         return err;
  75         }
  76
  77         tfm->authsize = authsize;
  78         return 0;
  79 }
  80 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  81
  82 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
  83 {
  84         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  85         struct aead_alg *alg = crypto_aead_alg(aead);
  86
  87         alg->exit(aead);
  88 }
  89
  90 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  91 {
  92         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  93         struct aead_alg *alg = crypto_aead_alg(aead);
  94
  95         aead->authsize = alg->maxauthsize;
  96
  97         if (alg->exit)
  98                 aead->base.exit = crypto_aead_exit_tfm;
  99
 100         if (alg->init)
 101                 return alg->init(aead);
 102
 103         return 0;
 104 }
 105
 106 #ifdef CONFIG_NET
 107 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 108 {
 109         struct crypto_report_aead raead;
 110         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 111
 112         strncpy(raead.type, "aead", sizeof(raead.type));
 113         strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
 114
 115         raead.blocksize = alg->cra_blocksize;
 116         raead.maxauthsize = aead->maxauthsize;
 117         raead.ivsize = aead->ivsize;
 118
 119         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 120                     sizeof(struct crypto_report_aead), &raead))
 121                 goto nla_put_failure;
 122         return 0;
 123
 124 nla_put_failure:
 125         return -EMSGSIZE;
 126 }
 127 #else
 128 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 129 {
 130         return -ENOSYS;
 131 }
 132 #endif
 133
 134 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 135         __attribute__ ((unused));
 136 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 137 {
 138         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 139
 140         seq_printf(m, "type         : aead\n");
 141         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 142                                              "yes" : "no");
 143         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 144         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 145         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 146         seq_printf(m, "geniv        : <none>\n");
 147 }
 148
 149 static void crypto_aead_free_instance(struct crypto_instance *inst)
 150 {
 151         struct aead_instance *aead = aead_instance(inst);
 152
 153         if (!aead->free) {
 154                 inst->tmpl->free(inst);
 155                 return;
 156         }
 157
 158         aead->free(aead);
 159 }
 160
 161 static const struct crypto_type crypto_aead_type = {
 162         .extsize = crypto_alg_extsize,
 163         .init_tfm = crypto_aead_init_tfm,
 164         .free = crypto_aead_free_instance,
 165 #ifdef CONFIG_PROC_FS
 166         .show = crypto_aead_show,
 167 #endif
 168         .report = crypto_aead_report,
 169         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 170         .maskset = CRYPTO_ALG_TYPE_MASK,
 171         .type = CRYPTO_ALG_TYPE_AEAD,
 172         .tfmsize = offsetof(struct crypto_aead, base),
 173 };
 174
 175 static int aead_geniv_setkey(struct crypto_aead *tfm,
 176                              const u8 *key, unsigned int keylen)
 177 {
 178         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 179
 180         return crypto_aead_setkey(ctx->child, key, keylen);
 181 }
 182
 183 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
 184                                   unsigned int authsize)
 185 {
 186         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 187
 188         return crypto_aead_setauthsize(ctx->child, authsize);
 189 }
 190
 191 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 192                                        struct rtattr **tb, u32 type, u32 mask)
 193 {
 194         const char *name;
 195         struct crypto_aead_spawn *spawn;
 196         struct crypto_attr_type *algt;
 197         struct aead_instance *inst;
 198         struct aead_alg *alg;
 199         unsigned int ivsize;
 200         unsigned int maxauthsize;
 201         int err;
 202
 203         algt = crypto_get_attr_type(tb);
 204         if (IS_ERR(algt))
 205                 return ERR_CAST(algt);
 206
 207         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) &
 208             algt->mask & ~CRYPTO_ALG_AEAD_NEW)
 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 &
 249                                    (CRYPTO_ALG_ASYNC | CRYPTO_ALG_AEAD_NEW);
 250         inst->alg.base.cra_priority = alg->base.cra_priority;
 251         inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 252         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 253         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 254
 255         inst->alg.setkey = aead_geniv_setkey;
 256         inst->alg.setauthsize = aead_geniv_setauthsize;
 257
 258         inst->alg.ivsize = ivsize;
 259         inst->alg.maxauthsize = maxauthsize;
 260
 261 out:
 262         return inst;
 263
 264 err_drop_alg:
 265         crypto_drop_aead(spawn);
 266 err_free_inst:
 267         kfree(inst);
 268         inst = ERR_PTR(err);
 269         goto out;
 270 }
 271 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 272
 273 void aead_geniv_free(struct aead_instance *inst)
 274 {
 275         crypto_drop_aead(aead_instance_ctx(inst));
 276         kfree(inst);
 277 }
 278 EXPORT_SYMBOL_GPL(aead_geniv_free);
 279
 280 int aead_init_geniv(struct crypto_aead *aead)
 281 {
 282         struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
 283         struct aead_instance *inst = aead_alg_instance(aead);
 284         struct crypto_aead *child;
 285         int err;
 286
 287         spin_lock_init(&ctx->lock);
 288
 289         err = crypto_get_default_rng();
 290         if (err)
 291                 goto out;
 292
 293         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 294                                    crypto_aead_ivsize(aead));
 295         crypto_put_default_rng();
 296         if (err)
 297                 goto out;
 298
 299         ctx->null = crypto_get_default_null_skcipher();
 300         err = PTR_ERR(ctx->null);
 301         if (IS_ERR(ctx->null))
 302                 goto out;
 303
 304         child = crypto_spawn_aead(aead_instance_ctx(inst));
 305         err = PTR_ERR(child);
 306         if (IS_ERR(child))
 307                 goto drop_null;
 308
 309         ctx->child = child;
 310         crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
 311                                       sizeof(struct aead_request));
 312
 313         err = 0;
 314
 315 out:
 316         return err;
 317
 318 drop_null:
 319         crypto_put_default_null_skcipher();
 320         goto out;
 321 }
 322 EXPORT_SYMBOL_GPL(aead_init_geniv);
 323
 324 void aead_exit_geniv(struct crypto_aead *tfm)
 325 {
 326         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 327
 328         crypto_free_aead(ctx->child);
 329         crypto_put_default_null_skcipher();
 330 }
 331 EXPORT_SYMBOL_GPL(aead_exit_geniv);
 332
 333 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 334                      u32 type, u32 mask)
 335 {
 336         spawn->base.frontend = &crypto_aead_type;
 337         return crypto_grab_spawn(&spawn->base, name, type, mask);
 338 }
 339 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 340
 341 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 342 {
 343         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 344 }
 345 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 346
 347 static int aead_prepare_alg(struct aead_alg *alg)
 348 {
 349         struct crypto_alg *base = &alg->base;
 350
 351         if (max(alg->maxauthsize, alg->ivsize) > PAGE_SIZE / 8)
 352                 return -EINVAL;
 353
 354         base->cra_type = &crypto_aead_type;
 355         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 356         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 357
 358         return 0;
 359 }
 360
 361 int crypto_register_aead(struct aead_alg *alg)
 362 {
 363         struct crypto_alg *base = &alg->base;
 364         int err;
 365
 366         err = aead_prepare_alg(alg);
 367         if (err)
 368                 return err;
 369
 370         return crypto_register_alg(base);
 371 }
 372 EXPORT_SYMBOL_GPL(crypto_register_aead);
 373
 374 void crypto_unregister_aead(struct aead_alg *alg)
 375 {
 376         crypto_unregister_alg(&alg->base);
 377 }
 378 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 379
 380 int crypto_register_aeads(struct aead_alg *algs, int count)
 381 {
 382         int i, ret;
 383
 384         for (i = 0; i < count; i++) {
 385                 ret = crypto_register_aead(&algs[i]);
 386                 if (ret)
 387                         goto err;
 388         }
 389
 390         return 0;
 391
 392 err:
 393         for (--i; i >= 0; --i)
 394                 crypto_unregister_aead(&algs[i]);
 395
 396         return ret;
 397 }
 398 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 399
 400 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 401 {
 402         int i;
 403
 404         for (i = count - 1; i >= 0; --i)
 405                 crypto_unregister_aead(&algs[i]);
 406 }
 407 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 408
 409 int aead_register_instance(struct crypto_template *tmpl,
 410                            struct aead_instance *inst)
 411 {
 412         int err;
 413
 414         err = aead_prepare_alg(&inst->alg);
 415         if (err)
 416                 return err;
 417
 418         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 419 }
 420 EXPORT_SYMBOL_GPL(aead_register_instance);
 421
 422 MODULE_LICENSE("GPL");
 423 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");