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