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