crypto/aead.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * AEAD: Authenticated Encryption with Associated Data
   4  *
   5  * This file provides API support for AEAD algorithms.
   6  *
   7  * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>
   8  */
   9
  10 #include <crypto/internal/geniv.h>
  11 #include <crypto/internal/rng.h>
  12 #include <crypto/null.h>
  13 #include <crypto/scatterwalk.h>
  14 #include <linux/err.h>
  15 #include <linux/init.h>
  16 #include <linux/kernel.h>
  17 #include <linux/module.h>
  18 #include <linux/rtnetlink.h>
  19 #include <linux/slab.h>
  20 #include <linux/seq_file.h>
  21 #include <linux/cryptouser.h>
  22 #include <linux/compiler.h>
  23 #include <net/netlink.h>
  24
  25 #include "internal.h"
  26
  27 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  28                             unsigned int keylen)
  29 {
  30         unsigned long alignmask = crypto_aead_alignmask(tfm);
  31         int ret;
  32         u8 *buffer, *alignbuffer;
  33         unsigned long absize;
  34
  35         absize = keylen + alignmask;
  36         buffer = kmalloc(absize, GFP_ATOMIC);
  37         if (!buffer)
  38                 return -ENOMEM;
  39
  40         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  41         memcpy(alignbuffer, key, keylen);
  42         ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
  43         memset(alignbuffer, 0, keylen);
  44         kfree(buffer);
  45         return ret;
  46 }
  47
  48 int crypto_aead_setkey(struct crypto_aead *tfm,
  49                        const u8 *key, unsigned int keylen)
  50 {
  51         unsigned long alignmask = crypto_aead_alignmask(tfm);
  52         int err;
  53
  54         if ((unsigned long)key & alignmask)
  55                 err = setkey_unaligned(tfm, key, keylen);
  56         else
  57                 err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
  58
  59         if (unlikely(err)) {
  60                 crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  61                 return err;
  62         }
  63
  64         crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  65         return 0;
  66 }
  67 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  68
  69 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  70 {
  71         int err;
  72
  73         if (authsize > crypto_aead_maxauthsize(tfm))
  74                 return -EINVAL;
  75
  76         if (crypto_aead_alg(tfm)->setauthsize) {
  77                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  78                 if (err)
  79                         return err;
  80         }
  81
  82         tfm->authsize = authsize;
  83         return 0;
  84 }
  85 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  86
  87 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
  88 {
  89         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  90         struct aead_alg *alg = crypto_aead_alg(aead);
  91
  92         alg->exit(aead);
  93 }
  94
  95 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  96 {
  97         struct crypto_aead *aead = __crypto_aead_cast(tfm);
  98         struct aead_alg *alg = crypto_aead_alg(aead);
  99
 100         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 101
 102         aead->authsize = alg->maxauthsize;
 103
 104         if (alg->exit)
 105                 aead->base.exit = crypto_aead_exit_tfm;
 106
 107         if (alg->init)
 108                 return alg->init(aead);
 109
 110         return 0;
 111 }
 112
 113 #ifdef CONFIG_NET
 114 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 115 {
 116         struct crypto_report_aead raead;
 117         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 118
 119         memset(&raead, 0, sizeof(raead));
 120
 121         strscpy(raead.type, "aead", sizeof(raead.type));
 122         strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
 123
 124         raead.blocksize = alg->cra_blocksize;
 125         raead.maxauthsize = aead->maxauthsize;
 126         raead.ivsize = aead->ivsize;
 127
 128         return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
 129 }
 130 #else
 131 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 132 {
 133         return -ENOSYS;
 134 }
 135 #endif
 136
 137 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 138         __maybe_unused;
 139 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 140 {
 141         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 142
 143         seq_printf(m, "type         : aead\n");
 144         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 145                                              "yes" : "no");
 146         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 147         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 148         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 149         seq_printf(m, "geniv        : <none>\n");
 150 }
 151
 152 static void crypto_aead_free_instance(struct crypto_instance *inst)
 153 {
 154         struct aead_instance *aead = aead_instance(inst);
 155
 156         if (!aead->free) {
 157                 inst->tmpl->free(inst);
 158                 return;
 159         }
 160
 161         aead->free(aead);
 162 }
 163
 164 static const struct crypto_type crypto_aead_type = {
 165         .extsize = crypto_alg_extsize,
 166         .init_tfm = crypto_aead_init_tfm,
 167         .free = crypto_aead_free_instance,
 168 #ifdef CONFIG_PROC_FS
 169         .show = crypto_aead_show,
 170 #endif
 171         .report = crypto_aead_report,
 172         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 173         .maskset = CRYPTO_ALG_TYPE_MASK,
 174         .type = CRYPTO_ALG_TYPE_AEAD,
 175         .tfmsize = offsetof(struct crypto_aead, base),
 176 };
 177
 178 static int aead_geniv_setkey(struct crypto_aead *tfm,
 179                              const u8 *key, unsigned int keylen)
 180 {
 181         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 182
 183         return crypto_aead_setkey(ctx->child, key, keylen);
 184 }
 185
 186 static int aead_geniv_setauthsize(struct crypto_aead *tfm,
 187                                   unsigned int authsize)
 188 {
 189         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 190
 191         return crypto_aead_setauthsize(ctx->child, authsize);
 192 }
 193
 194 struct aead_instance *aead_geniv_alloc(struct crypto_template *tmpl,
 195                                        struct rtattr **tb, u32 type, u32 mask)
 196 {
 197         const char *name;
 198         struct crypto_aead_spawn *spawn;
 199         struct crypto_attr_type *algt;
 200         struct aead_instance *inst;
 201         struct aead_alg *alg;
 202         unsigned int ivsize;
 203         unsigned int maxauthsize;
 204         int err;
 205
 206         algt = crypto_get_attr_type(tb);
 207         if (IS_ERR(algt))
 208                 return ERR_CAST(algt);
 209
 210         if ((algt->type ^ CRYPTO_ALG_TYPE_AEAD) & algt->mask)
 211                 return ERR_PTR(-EINVAL);
 212
 213         name = crypto_attr_alg_name(tb[1]);
 214         if (IS_ERR(name))
 215                 return ERR_CAST(name);
 216
 217         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
 218         if (!inst)
 219                 return ERR_PTR(-ENOMEM);
 220
 221         spawn = aead_instance_ctx(inst);
 222
 223         /* Ignore async algorithms if necessary. */
 224         mask |= crypto_requires_sync(algt->type, algt->mask);
 225
 226         crypto_set_aead_spawn(spawn, aead_crypto_instance(inst));
 227         err = crypto_grab_aead(spawn, name, type, mask);
 228         if (err)
 229                 goto err_free_inst;
 230
 231         alg = crypto_spawn_aead_alg(spawn);
 232
 233         ivsize = crypto_aead_alg_ivsize(alg);
 234         maxauthsize = crypto_aead_alg_maxauthsize(alg);
 235
 236         err = -EINVAL;
 237         if (ivsize < sizeof(u64))
 238                 goto err_drop_alg;
 239
 240         err = -ENAMETOOLONG;
 241         if (snprintf(inst->alg.base.cra_name, CRYPTO_MAX_ALG_NAME,
 242                      "%s(%s)", tmpl->name, alg->base.cra_name) >=
 243             CRYPTO_MAX_ALG_NAME)
 244                 goto err_drop_alg;
 245         if (snprintf(inst->alg.base.cra_driver_name, CRYPTO_MAX_ALG_NAME,
 246                      "%s(%s)", tmpl->name, alg->base.cra_driver_name) >=
 247             CRYPTO_MAX_ALG_NAME)
 248                 goto err_drop_alg;
 249
 250         inst->alg.base.cra_flags = alg->base.cra_flags & CRYPTO_ALG_ASYNC;
 251         inst->alg.base.cra_priority = alg->base.cra_priority;
 252         inst->alg.base.cra_blocksize = alg->base.cra_blocksize;
 253         inst->alg.base.cra_alignmask = alg->base.cra_alignmask;
 254         inst->alg.base.cra_ctxsize = sizeof(struct aead_geniv_ctx);
 255
 256         inst->alg.setkey = aead_geniv_setkey;
 257         inst->alg.setauthsize = aead_geniv_setauthsize;
 258
 259         inst->alg.ivsize = ivsize;
 260         inst->alg.maxauthsize = maxauthsize;
 261
 262 out:
 263         return inst;
 264
 265 err_drop_alg:
 266         crypto_drop_aead(spawn);
 267 err_free_inst:
 268         kfree(inst);
 269         inst = ERR_PTR(err);
 270         goto out;
 271 }
 272 EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 273
 274 void aead_geniv_free(struct aead_instance *inst)
 275 {
 276         crypto_drop_aead(aead_instance_ctx(inst));
 277         kfree(inst);
 278 }
 279 EXPORT_SYMBOL_GPL(aead_geniv_free);
 280
 281 int aead_init_geniv(struct crypto_aead *aead)
 282 {
 283         struct aead_geniv_ctx *ctx = crypto_aead_ctx(aead);
 284         struct aead_instance *inst = aead_alg_instance(aead);
 285         struct crypto_aead *child;
 286         int err;
 287
 288         spin_lock_init(&ctx->lock);
 289
 290         err = crypto_get_default_rng();
 291         if (err)
 292                 goto out;
 293
 294         err = crypto_rng_get_bytes(crypto_default_rng, ctx->salt,
 295                                    crypto_aead_ivsize(aead));
 296         crypto_put_default_rng();
 297         if (err)
 298                 goto out;
 299
 300         ctx->sknull = crypto_get_default_null_skcipher();
 301         err = PTR_ERR(ctx->sknull);
 302         if (IS_ERR(ctx->sknull))
 303                 goto out;
 304
 305         child = crypto_spawn_aead(aead_instance_ctx(inst));
 306         err = PTR_ERR(child);
 307         if (IS_ERR(child))
 308                 goto drop_null;
 309
 310         ctx->child = child;
 311         crypto_aead_set_reqsize(aead, crypto_aead_reqsize(child) +
 312                                       sizeof(struct aead_request));
 313
 314         err = 0;
 315
 316 out:
 317         return err;
 318
 319 drop_null:
 320         crypto_put_default_null_skcipher();
 321         goto out;
 322 }
 323 EXPORT_SYMBOL_GPL(aead_init_geniv);
 324
 325 void aead_exit_geniv(struct crypto_aead *tfm)
 326 {
 327         struct aead_geniv_ctx *ctx = crypto_aead_ctx(tfm);
 328
 329         crypto_free_aead(ctx->child);
 330         crypto_put_default_null_skcipher();
 331 }
 332 EXPORT_SYMBOL_GPL(aead_exit_geniv);
 333
 334 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 335                      u32 type, u32 mask)
 336 {
 337         spawn->base.frontend = &crypto_aead_type;
 338         return crypto_grab_spawn(&spawn->base, name, type, mask);
 339 }
 340 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 341
 342 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 343 {
 344         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 345 }
 346 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 347
 348 static int aead_prepare_alg(struct aead_alg *alg)
 349 {
 350         struct crypto_alg *base = &alg->base;
 351
 352         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 353             PAGE_SIZE / 8)
 354                 return -EINVAL;
 355
 356         if (!alg->chunksize)
 357                 alg->chunksize = base->cra_blocksize;
 358
 359         base->cra_type = &crypto_aead_type;
 360         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 361         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 362
 363         return 0;
 364 }
 365
 366 int crypto_register_aead(struct aead_alg *alg)
 367 {
 368         struct crypto_alg *base = &alg->base;
 369         int err;
 370
 371         err = aead_prepare_alg(alg);
 372         if (err)
 373                 return err;
 374
 375         return crypto_register_alg(base);
 376 }
 377 EXPORT_SYMBOL_GPL(crypto_register_aead);
 378
 379 void crypto_unregister_aead(struct aead_alg *alg)
 380 {
 381         crypto_unregister_alg(&alg->base);
 382 }
 383 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 384
 385 int crypto_register_aeads(struct aead_alg *algs, int count)
 386 {
 387         int i, ret;
 388
 389         for (i = 0; i < count; i++) {
 390                 ret = crypto_register_aead(&algs[i]);
 391                 if (ret)
 392                         goto err;
 393         }
 394
 395         return 0;
 396
 397 err:
 398         for (--i; i >= 0; --i)
 399                 crypto_unregister_aead(&algs[i]);
 400
 401         return ret;
 402 }
 403 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 404
 405 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 406 {
 407         int i;
 408
 409         for (i = count - 1; i >= 0; --i)
 410                 crypto_unregister_aead(&algs[i]);
 411 }
 412 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 413
 414 int aead_register_instance(struct crypto_template *tmpl,
 415                            struct aead_instance *inst)
 416 {
 417         int err;
 418
 419         err = aead_prepare_alg(&inst->alg);
 420         if (err)
 421                 return err;
 422
 423         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 424 }
 425 EXPORT_SYMBOL_GPL(aead_register_instance);
 426
 427 MODULE_LICENSE("GPL");
 428 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");