linux/crypto/aead.c
<<
>>
Prefs
   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
  32static 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
  53int 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}
  70EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  71
  72int 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}
  88EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  89
  90static 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
  98static 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
 117static 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
 134nla_put_failure:
 135        return -EMSGSIZE;
 136}
 137#else
 138static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 139{
 140        return -ENOSYS;
 141}
 142#endif
 143
 144static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 145        __maybe_unused;
 146static 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
 159static 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
 171static 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
 185static 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
 193static 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
 201struct 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
 269out:
 270        return inst;
 271
 272err_drop_alg:
 273        crypto_drop_aead(spawn);
 274err_free_inst:
 275        kfree(inst);
 276        inst = ERR_PTR(err);
 277        goto out;
 278}
 279EXPORT_SYMBOL_GPL(aead_geniv_alloc);
 280
 281void aead_geniv_free(struct aead_instance *inst)
 282{
 283        crypto_drop_aead(aead_instance_ctx(inst));
 284        kfree(inst);
 285}
 286EXPORT_SYMBOL_GPL(aead_geniv_free);
 287
 288int 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
 323out:
 324        return err;
 325
 326drop_null:
 327        crypto_put_default_null_skcipher();
 328        goto out;
 329}
 330EXPORT_SYMBOL_GPL(aead_init_geniv);
 331
 332void 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}
 339EXPORT_SYMBOL_GPL(aead_exit_geniv);
 340
 341int 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}
 347EXPORT_SYMBOL_GPL(crypto_grab_aead);
 348
 349struct 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}
 353EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 354
 355static 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
 373int 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}
 384EXPORT_SYMBOL_GPL(crypto_register_aead);
 385
 386void crypto_unregister_aead(struct aead_alg *alg)
 387{
 388        crypto_unregister_alg(&alg->base);
 389}
 390EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 391
 392int 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
 404err:
 405        for (--i; i >= 0; --i)
 406                crypto_unregister_aead(&algs[i]);
 407
 408        return ret;
 409}
 410EXPORT_SYMBOL_GPL(crypto_register_aeads);
 411
 412void 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}
 419EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 420
 421int 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}
 432EXPORT_SYMBOL_GPL(aead_register_instance);
 433
 434MODULE_LICENSE("GPL");
 435MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
 436