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         int err;
  58
  59         if ((unsigned long)key & alignmask)
  60                 err = setkey_unaligned(tfm, key, keylen);
  61         else
  62                 err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
  63
  64         if (err)
  65                 return err;
  66
  67         crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  68         return 0;
  69 }
  70 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  71
  72 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  73 {
  74         int err;
  75
  76         if (authsize > crypto_aead_maxauthsize(tfm))
  77                 return -EINVAL;
  78
  79         if (crypto_aead_alg(tfm)->setauthsize) {
  80                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  81                 if (err)
  82                         return err;
  83         }
  84
  85         tfm->authsize = authsize;
  86         return 0;
  87 }
  88 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  89
  90 static void crypto_aead_exit_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         alg->exit(aead);
  96 }
  97
  98 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  99 {
 100         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 101         struct aead_alg *alg = crypto_aead_alg(aead);
 102
 103         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 104
 105         aead->authsize = alg->maxauthsize;
 106
 107         if (alg->exit)
 108                 aead->base.exit = crypto_aead_exit_tfm;
 109
 110         if (alg->init)
 111                 return alg->init(aead);
 112
 113         return 0;
 114 }
 115
 116 #ifdef CONFIG_NET
 117 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 118 {
 119         struct crypto_report_aead raead;
 120         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 121
 122         strncpy(raead.type, "aead", sizeof(raead.type));
 123         strncpy(raead.geniv, "<none>", sizeof(raead.geniv));
 124
 125         raead.blocksize = alg->cra_blocksize;
 126         raead.maxauthsize = aead->maxauthsize;
 127         raead.ivsize = aead->ivsize;
 128
 129         if (nla_put(skb, CRYPTOCFGA_REPORT_AEAD,
 130                     sizeof(struct crypto_report_aead), &raead))
 131                 goto nla_put_failure;
 132         return 0;
 133
 134 nla_put_failure:
 135         return -EMSGSIZE;
 136 }
 137 #else
 138 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 139 {
 140         return -ENOSYS;
 141 }
 142 #endif
 143
 144 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 145         __maybe_unused;
 146 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 147 {
 148         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 149
 150         seq_printf(m, "type         : aead\n");
 151         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 152                                              "yes" : "no");
 153         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 154         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 155         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 156         seq_printf(m, "geniv        : <none>\n");
 157 }
 158
 159 static void crypto_aead_free_instance(struct crypto_instance *inst)
 160 {
 161         struct aead_instance *aead = aead_instance(inst);
 162
 163         if (!aead->free) {
 164                 inst->tmpl->free(inst);
 165                 return;
 166         }
 167
 168         aead->free(aead);
 169 }
 170
 171 static const struct crypto_type crypto_aead_type = {
 172         .extsize = crypto_alg_extsize,
 173         .init_tfm = crypto_aead_init_tfm,
 174         .free = crypto_aead_free_instance,
 175 #ifdef CONFIG_PROC_FS
 176         .show = crypto_aead_show,
 177 #endif
 178         .report = crypto_aead_report,
 179         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 180         .maskset = CRYPTO_ALG_TYPE_MASK,
 181         .type = CRYPTO_ALG_TYPE_AEAD,
 182         .tfmsize = offsetof(struct crypto_aead, base),
 183 };
 184
 185 static int aead_geniv_setkey(struct crypto_aead *tfm,
 186                              const u8 *key, unsigned int keylen)
 187 {
 188         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 189
 190         return crypto_aead_setkey(ctx->child, key, keylen);
 191 }
 192
 193 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
 194                                   unsigned int authsize)
 195 {
 196         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 197
 198         return crypto_aead_setauthsize(ctx->child, authsize);
 199 }
 200
 201 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 202                                        struct rtattr **tb, u32 type, u32 mask)
 203 {
 204         const char *name;
 205         struct crypto_aead_spawn *spawn;
 206         struct crypto_attr_type *algt;
 207         struct aead_instance *inst;
 208         struct aead_alg *alg;
 209         unsigned int ivsize;
 210         unsigned int maxauthsize;
 211         int err;
 212
 213         algt = crypto_get_attr_type(tb);
 214         if (IS_ERR(algt))
 215                 return ERR_CAST(algt);
 216
 217         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 218                 return ERR_PTR(-EINVAL);
 219
 220         name = crypto_attr_alg_name(tb[1]);
 221         if (IS_ERR(name))
 222                 return ERR_CAST(name);
 223
 224         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 225         if (!inst)
 226                 return ERR_PTR(-ENOMEM);
 227
 228         spawn = aead_instance_ctx(inst);
 229
 230         /* Ignore async algorithms if necessary. */
 231         mask |= crypto_requires_sync(algt->type, algt->mask);
 232
 233         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 234         err = crypto_grab_aead(spawn, name, type, mask);
 235         if (err)
 236                 goto err_free_inst;
 237
 238         alg = crypto_spawn_aead_alg(spawn);
 239
 240         ivsize = crypto_aead_alg_ivsize(alg);
 241         maxauthsize = crypto_aead_alg_maxauthsize(alg);
 242
 243         err = -EINVAL;
 244         if (ivsize < sizeof(u64))
 245                 goto err_drop_alg;
 246
 247         err = -ENAMETOOLONG;
 248         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 249                      "%s(%s)", tmpl->name, alg->base.cra_name) >=
 250             CRYPTO_MAX_ALG_NAME)
 251                 goto err_drop_alg;
 252         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 253                      "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
 254             CRYPTO_MAX_ALG_NAME)
 255                 goto err_drop_alg;
 256
 257         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 258         inst->alg.base.cra_priority = alg->base.cra_priority;
 259         inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 260         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 261         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 262
 263         inst->alg.setkey = aead_geniv_setkey;
 264         inst->alg.setauthsize = aead_geniv_setauthsize;
 265
 266         inst->alg.ivsize = ivsize;
 267         inst->alg.maxauthsize = maxauthsize;
 268
 269 out:
 270         return inst;
 271
 272 err_drop_alg:
 273         crypto_drop_aead(spawn);
 274 err_free_inst:
 275         kfree(inst);
 276         inst = ERR_PTR(err);
 277         goto out;
 278 }
 279 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 280
 281 void aead_geniv_free(struct aead_instance *inst)
 282 {
 283         crypto_drop_aead(aead_instance_ctx(inst));
 284         kfree(inst);
 285 }
 286 EXPORT_SYMBOL_GPL(aead_geniv_free);
 287
 288 int aead_init_geniv(struct crypto_aead *aead)
 289 {
 290         struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
 291         struct aead_instance *inst = aead_alg_instance(aead);
 292         struct crypto_aead *child;
 293         int err;
 294
 295         spin_lock_init(&ctx->lock);
 296
 297         err = crypto_get_default_rng();
 298         if (err)
 299                 goto out;
 300
 301         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 302                                    crypto_aead_ivsize(aead));
 303         crypto_put_default_rng();
 304         if (err)
 305                 goto out;
 306
 307         ctx->sknull = crypto_get_default_null_skcipher();
 308         err = PTR_ERR(ctx->sknull);
 309         if (IS_ERR(ctx->sknull))
 310                 goto out;
 311
 312         child = crypto_spawn_aead(aead_instance_ctx(inst));
 313         err = PTR_ERR(child);
 314         if (IS_ERR(child))
 315                 goto drop_null;
 316
 317         ctx->child = child;
 318         crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
 319                                       sizeof(struct aead_request));
 320
 321         err = 0;
 322
 323 out:
 324         return err;
 325
 326 drop_null:
 327         crypto_put_default_null_skcipher();
 328         goto out;
 329 }
 330 EXPORT_SYMBOL_GPL(aead_init_geniv);
 331
 332 void aead_exit_geniv(struct crypto_aead *tfm)
 333 {
 334         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 335
 336         crypto_free_aead(ctx->child);
 337         crypto_put_default_null_skcipher();
 338 }
 339 EXPORT_SYMBOL_GPL(aead_exit_geniv);
 340
 341 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 342                      u32 type, u32 mask)
 343 {
 344         spawn->base.frontend = &crypto_aead_type;
 345         return crypto_grab_spawn(&spawn->base, name, type, mask);
 346 }
 347 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 348
 349 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 350 {
 351         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 352 }
 353 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 354
 355 static int aead_prepare_alg(struct aead_alg *alg)
 356 {
 357         struct crypto_alg *base = &alg->base;
 358
 359         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 360             PAGE_SIZE / 8)
 361                 return -EINVAL;
 362
 363         if (!alg->chunksize)
 364                 alg->chunksize = base->cra_blocksize;
 365
 366         base->cra_type = &crypto_aead_type;
 367         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 368         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 369
 370         return 0;
 371 }
 372
 373 int crypto_register_aead(struct aead_alg *alg)
 374 {
 375         struct crypto_alg *base = &alg->base;
 376         int err;
 377
 378         err = aead_prepare_alg(alg);
 379         if (err)
 380                 return err;
 381
 382         return crypto_register_alg(base);
 383 }
 384 EXPORT_SYMBOL_GPL(crypto_register_aead);
 385
 386 void crypto_unregister_aead(struct aead_alg *alg)
 387 {
 388         crypto_unregister_alg(&alg->base);
 389 }
 390 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 391
 392 int crypto_register_aeads(struct aead_alg *algs, int count)
 393 {
 394         int i, ret;
 395
 396         for (i = 0; i < count; i++) {
 397                 ret = crypto_register_aead(&algs[i]);
 398                 if (ret)
 399                         goto err;
 400         }
 401
 402         return 0;
 403
 404 err:
 405         for (--i; i >= 0; --i)
 406                 crypto_unregister_aead(&algs[i]);
 407
 408         return ret;
 409 }
 410 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 411
 412 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 413 {
 414         int i;
 415
 416         for (i = count - 1; i >= 0; --i)
 417                 crypto_unregister_aead(&algs[i]);
 418 }
 419 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 420
 421 int aead_register_instance(struct crypto_template *tmpl,
 422                            struct aead_instance *inst)
 423 {
 424         int err;
 425
 426         err = aead_prepare_alg(&inst->alg);
 427         if (err)
 428                 return err;
 429
 430         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 431 }
 432 EXPORT_SYMBOL_GPL(aead_register_instance);
 433
 434 MODULE_LICENSE("GPL");
 435 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");