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 (unlikely(err)) {
  65                 crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  66                 return err;
  67         }
  68
  69         crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  70         return 0;
  71 }
  72 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  73
  74 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  75 {
  76         int err;
  77
  78         if (authsize > crypto_aead_maxauthsize(tfm))
  79                 return -EINVAL;
  80
  81         if (crypto_aead_alg(tfm)->setauthsize) {
  82                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  83                 if (err)
  84                         return err;
  85         }
  86
  87         tfm->authsize = authsize;
  88         return 0;
  89 }
  90 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  91
  92 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
  93 {
  94         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  95         struct aead_alg *alg = crypto_aead_alg(aead);
  96
  97         alg->exit(aead);
  98 }
  99
 100 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
 101 {
 102         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 103         struct aead_alg *alg = crypto_aead_alg(aead);
 104
 105         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 106
 107         aead->authsize = alg->maxauthsize;
 108
 109         if (alg->exit)
 110                 aead->base.exit = crypto_aead_exit_tfm;
 111
 112         if (alg->init)
 113                 return alg->init(aead);
 114
 115         return 0;
 116 }
 117
 118 #ifdef CONFIG_NET
 119 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 120 {
 121         struct crypto_report_aead raead;
 122         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 123
 124         memset(&raead, 0, sizeof(raead));
 125
 126         strscpy(raead.type, "aead", sizeof(raead.type));
 127         strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
 128
 129         raead.blocksize = alg->cra_blocksize;
 130         raead.maxauthsize = aead->maxauthsize;
 131         raead.ivsize = aead->ivsize;
 132
 133         return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
 134 }
 135 #else
 136 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 137 {
 138         return -ENOSYS;
 139 }
 140 #endif
 141
 142 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 143         __maybe_unused;
 144 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 145 {
 146         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 147
 148         seq_printf(m, "type         : aead\n");
 149         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 150                                              "yes" : "no");
 151         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 152         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 153         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 154         seq_printf(m, "geniv        : <none>\n");
 155 }
 156
 157 static void crypto_aead_free_instance(struct crypto_instance *inst)
 158 {
 159         struct aead_instance *aead = aead_instance(inst);
 160
 161         if (!aead->free) {
 162                 inst->tmpl->free(inst);
 163                 return;
 164         }
 165
 166         aead->free(aead);
 167 }
 168
 169 static const struct crypto_type crypto_aead_type = {
 170         .extsize = crypto_alg_extsize,
 171         .init_tfm = crypto_aead_init_tfm,
 172         .free = crypto_aead_free_instance,
 173 #ifdef CONFIG_PROC_FS
 174         .show = crypto_aead_show,
 175 #endif
 176         .report = crypto_aead_report,
 177         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 178         .maskset = CRYPTO_ALG_TYPE_MASK,
 179         .type = CRYPTO_ALG_TYPE_AEAD,
 180         .tfmsize = offsetof(struct crypto_aead, base),
 181 };
 182
 183 static int aead_geniv_setkey(struct crypto_aead *tfm,
 184                              const u8 *key, unsigned int keylen)
 185 {
 186         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 187
 188         return crypto_aead_setkey(ctx->child, key, keylen);
 189 }
 190
 191 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
 192                                   unsigned int authsize)
 193 {
 194         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 195
 196         return crypto_aead_setauthsize(ctx->child, authsize);
 197 }
 198
 199 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 200                                        struct rtattr **tb, u32 type, u32 mask)
 201 {
 202         const char *name;
 203         struct crypto_aead_spawn *spawn;
 204         struct crypto_attr_type *algt;
 205         struct aead_instance *inst;
 206         struct aead_alg *alg;
 207         unsigned int ivsize;
 208         unsigned int maxauthsize;
 209         int err;
 210
 211         algt = crypto_get_attr_type(tb);
 212         if (IS_ERR(algt))
 213                 return ERR_CAST(algt);
 214
 215         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 216                 return ERR_PTR(-EINVAL);
 217
 218         name = crypto_attr_alg_name(tb[1]);
 219         if (IS_ERR(name))
 220                 return ERR_CAST(name);
 221
 222         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 223         if (!inst)
 224                 return ERR_PTR(-ENOMEM);
 225
 226         spawn = aead_instance_ctx(inst);
 227
 228         /* Ignore async algorithms if necessary. */
 229         mask |= crypto_requires_sync(algt->type, algt->mask);
 230
 231         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 232         err = crypto_grab_aead(spawn, name, type, mask);
 233         if (err)
 234                 goto err_free_inst;
 235
 236         alg = crypto_spawn_aead_alg(spawn);
 237
 238         ivsize = crypto_aead_alg_ivsize(alg);
 239         maxauthsize = crypto_aead_alg_maxauthsize(alg);
 240
 241         err = -EINVAL;
 242         if (ivsize < sizeof(u64))
 243                 goto err_drop_alg;
 244
 245         err = -ENAMETOOLONG;
 246         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 247                      "%s(%s)", tmpl->name, alg->base.cra_name) >=
 248             CRYPTO_MAX_ALG_NAME)
 249                 goto err_drop_alg;
 250         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 251                      "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
 252             CRYPTO_MAX_ALG_NAME)
 253                 goto err_drop_alg;
 254
 255         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 256         inst->alg.base.cra_priority = alg->base.cra_priority;
 257         inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 258         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 259         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 260
 261         inst->alg.setkey = aead_geniv_setkey;
 262         inst->alg.setauthsize = aead_geniv_setauthsize;
 263
 264         inst->alg.ivsize = ivsize;
 265         inst->alg.maxauthsize = maxauthsize;
 266
 267 out:
 268         return inst;
 269
 270 err_drop_alg:
 271         crypto_drop_aead(spawn);
 272 err_free_inst:
 273         kfree(inst);
 274         inst = ERR_PTR(err);
 275         goto out;
 276 }
 277 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 278
 279 void aead_geniv_free(struct aead_instance *inst)
 280 {
 281         crypto_drop_aead(aead_instance_ctx(inst));
 282         kfree(inst);
 283 }
 284 EXPORT_SYMBOL_GPL(aead_geniv_free);
 285
 286 int aead_init_geniv(struct crypto_aead *aead)
 287 {
 288         struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
 289         struct aead_instance *inst = aead_alg_instance(aead);
 290         struct crypto_aead *child;
 291         int err;
 292
 293         spin_lock_init(&ctx->lock);
 294
 295         err = crypto_get_default_rng();
 296         if (err)
 297                 goto out;
 298
 299         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 300                                    crypto_aead_ivsize(aead));
 301         crypto_put_default_rng();
 302         if (err)
 303                 goto out;
 304
 305         ctx->sknull = crypto_get_default_null_skcipher();
 306         err = PTR_ERR(ctx->sknull);
 307         if (IS_ERR(ctx->sknull))
 308                 goto out;
 309
 310         child = crypto_spawn_aead(aead_instance_ctx(inst));
 311         err = PTR_ERR(child);
 312         if (IS_ERR(child))
 313                 goto drop_null;
 314
 315         ctx->child = child;
 316         crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
 317                                       sizeof(struct aead_request));
 318
 319         err = 0;
 320
 321 out:
 322         return err;
 323
 324 drop_null:
 325         crypto_put_default_null_skcipher();
 326         goto out;
 327 }
 328 EXPORT_SYMBOL_GPL(aead_init_geniv);
 329
 330 void aead_exit_geniv(struct crypto_aead *tfm)
 331 {
 332         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 333
 334         crypto_free_aead(ctx->child);
 335         crypto_put_default_null_skcipher();
 336 }
 337 EXPORT_SYMBOL_GPL(aead_exit_geniv);
 338
 339 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 340                      u32 type, u32 mask)
 341 {
 342         spawn->base.frontend = &crypto_aead_type;
 343         return crypto_grab_spawn(&spawn->base, name, type, mask);
 344 }
 345 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 346
 347 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 348 {
 349         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 350 }
 351 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 352
 353 static int aead_prepare_alg(struct aead_alg *alg)
 354 {
 355         struct crypto_alg *base = &alg->base;
 356
 357         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 358             PAGE_SIZE / 8)
 359                 return -EINVAL;
 360
 361         if (!alg->chunksize)
 362                 alg->chunksize = base->cra_blocksize;
 363
 364         base->cra_type = &crypto_aead_type;
 365         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 366         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 367
 368         return 0;
 369 }
 370
 371 int crypto_register_aead(struct aead_alg *alg)
 372 {
 373         struct crypto_alg *base = &alg->base;
 374         int err;
 375
 376         err = aead_prepare_alg(alg);
 377         if (err)
 378                 return err;
 379
 380         return crypto_register_alg(base);
 381 }
 382 EXPORT_SYMBOL_GPL(crypto_register_aead);
 383
 384 void crypto_unregister_aead(struct aead_alg *alg)
 385 {
 386         crypto_unregister_alg(&alg->base);
 387 }
 388 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 389
 390 int crypto_register_aeads(struct aead_alg *algs, int count)
 391 {
 392         int i, ret;
 393
 394         for (i = 0; i < count; i++) {
 395                 ret = crypto_register_aead(&algs[i]);
 396                 if (ret)
 397                         goto err;
 398         }
 399
 400         return 0;
 401
 402 err:
 403         for (--i; i >= 0; --i)
 404                 crypto_unregister_aead(&algs[i]);
 405
 406         return ret;
 407 }
 408 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 409
 410 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 411 {
 412         int i;
 413
 414         for (i = count - 1; i >= 0; --i)
 415                 crypto_unregister_aead(&algs[i]);
 416 }
 417 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 418
 419 int aead_register_instance(struct crypto_template *tmpl,
 420                            struct aead_instance *inst)
 421 {
 422         int err;
 423
 424         err = aead_prepare_alg(&inst->alg);
 425         if (err)
 426                 return err;
 427
 428         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 429 }
 430 EXPORT_SYMBOL_GPL(aead_register_instance);
 431
 432 MODULE_LICENSE("GPL");
 433 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");