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/aead.h>
  11 #include <linux/cryptouser.h>
  12 #include <linux/errno.h>
  13 #include <linux/init.h>
  14 #include <linux/kernel.h>
  15 #include <linux/module.h>
  16 #include <linux/slab.h>
  17 #include <linux/seq_file.h>
  18 #include <linux/string.h>
  19 #include <net/netlink.h>
  20
  21 #include "internal.h"
  22
  23 static inline struct crypto_istat_aead *aead_get_stat(struct aead_alg *alg)
  24 {
  25 #ifdef CONFIG_CRYPTO_STATS
  26         return &alg->stat;
  27 #else
  28         return NULL;
  29 #endif
  30 }
  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             authsize > crypto_aead_maxauthsize(tfm))
  80                 return -EINVAL;
  81
  82         if (crypto_aead_alg(tfm)->setauthsize) {
  83                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  84                 if (err)
  85                         return err;
  86         }
  87
  88         tfm->authsize = authsize;
  89         return 0;
  90 }
  91 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  92
  93 static inline int crypto_aead_errstat(struct crypto_istat_aead *istat, int err)
  94 {
  95         if (!IS_ENABLED(CONFIG_CRYPTO_STATS))
  96                 return err;
  97
  98         if (err && err != -EINPROGRESS && err != -EBUSY)
  99                 atomic64_inc(&istat->err_cnt);
 100
 101         return err;
 102 }
 103
 104 int crypto_aead_encrypt(struct aead_request *req)
 105 {
 106         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 107         struct aead_alg *alg = crypto_aead_alg(aead);
 108         struct crypto_istat_aead *istat;
 109         int ret;
 110
 111         istat = aead_get_stat(alg);
 112
 113         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 114                 atomic64_inc(&istat->encrypt_cnt);
 115                 atomic64_add(req->cryptlen, &istat->encrypt_tlen);
 116         }
 117
 118         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
 119                 ret = -ENOKEY;
 120         else
 121                 ret = alg->encrypt(req);
 122
 123         return crypto_aead_errstat(istat, ret);
 124 }
 125 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
 126
 127 int crypto_aead_decrypt(struct aead_request *req)
 128 {
 129         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 130         struct aead_alg *alg = crypto_aead_alg(aead);
 131         struct crypto_istat_aead *istat;
 132         int ret;
 133
 134         istat = aead_get_stat(alg);
 135
 136         if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
 137                 atomic64_inc(&istat->encrypt_cnt);
 138                 atomic64_add(req->cryptlen, &istat->encrypt_tlen);
 139         }
 140
 141         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
 142                 ret = -ENOKEY;
 143         else if (req->cryptlen < crypto_aead_authsize(aead))
 144                 ret = -EINVAL;
 145         else
 146                 ret = alg->decrypt(req);
 147
 148         return crypto_aead_errstat(istat, ret);
 149 }
 150 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
 151
 152 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
 153 {
 154         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 155         struct aead_alg *alg = crypto_aead_alg(aead);
 156
 157         alg->exit(aead);
 158 }
 159
 160 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
 161 {
 162         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 163         struct aead_alg *alg = crypto_aead_alg(aead);
 164
 165         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 166
 167         aead->authsize = alg->maxauthsize;
 168
 169         if (alg->exit)
 170                 aead->base.exit = crypto_aead_exit_tfm;
 171
 172         if (alg->init)
 173                 return alg->init(aead);
 174
 175         return 0;
 176 }
 177
 178 static int __maybe_unused crypto_aead_report(
 179         struct sk_buff *skb, struct crypto_alg *alg)
 180 {
 181         struct crypto_report_aead raead;
 182         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 183
 184         memset(&raead, 0, sizeof(raead));
 185
 186         strscpy(raead.type, "aead", sizeof(raead.type));
 187         strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
 188
 189         raead.blocksize = alg->cra_blocksize;
 190         raead.maxauthsize = aead->maxauthsize;
 191         raead.ivsize = aead->ivsize;
 192
 193         return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
 194 }
 195
 196 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 197         __maybe_unused;
 198 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 199 {
 200         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 201
 202         seq_printf(m, "type         : aead\n");
 203         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 204                                              "yes" : "no");
 205         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 206         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 207         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 208         seq_printf(m, "geniv        : <none>\n");
 209 }
 210
 211 static void crypto_aead_free_instance(struct crypto_instance *inst)
 212 {
 213         struct aead_instance *aead = aead_instance(inst);
 214
 215         aead->free(aead);
 216 }
 217
 218 static int __maybe_unused crypto_aead_report_stat(
 219         struct sk_buff *skb, struct crypto_alg *alg)
 220 {
 221         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 222         struct crypto_istat_aead *istat = aead_get_stat(aead);
 223         struct crypto_stat_aead raead;
 224
 225         memset(&raead, 0, sizeof(raead));
 226
 227         strscpy(raead.type, "aead", sizeof(raead.type));
 228
 229         raead.stat_encrypt_cnt = atomic64_read(&istat->encrypt_cnt);
 230         raead.stat_encrypt_tlen = atomic64_read(&istat->encrypt_tlen);
 231         raead.stat_decrypt_cnt = atomic64_read(&istat->decrypt_cnt);
 232         raead.stat_decrypt_tlen = atomic64_read(&istat->decrypt_tlen);
 233         raead.stat_err_cnt = atomic64_read(&istat->err_cnt);
 234
 235         return nla_put(skb, CRYPTOCFGA_STAT_AEAD, sizeof(raead), &raead);
 236 }
 237
 238 static const struct crypto_type crypto_aead_type = {
 239         .extsize = crypto_alg_extsize,
 240         .init_tfm = crypto_aead_init_tfm,
 241         .free = crypto_aead_free_instance,
 242 #ifdef CONFIG_PROC_FS
 243         .show = crypto_aead_show,
 244 #endif
 245 #if IS_ENABLED(CONFIG_CRYPTO_USER)
 246         .report = crypto_aead_report,
 247 #endif
 248 #ifdef CONFIG_CRYPTO_STATS
 249         .report_stat = crypto_aead_report_stat,
 250 #endif
 251         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 252         .maskset = CRYPTO_ALG_TYPE_MASK,
 253         .type = CRYPTO_ALG_TYPE_AEAD,
 254         .tfmsize = offsetof(struct crypto_aead, base),
 255 };
 256
 257 int crypto_grab_aead(struct crypto_aead_spawn *spawn,
 258                      struct crypto_instance *inst,
 259                      const char *name, u32 type, u32 mask)
 260 {
 261         spawn->base.frontend = &crypto_aead_type;
 262         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 263 }
 264 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 265
 266 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 267 {
 268         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 269 }
 270 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 271
 272 int crypto_has_aead(const char *alg_name, u32 type, u32 mask)
 273 {
 274         return crypto_type_has_alg(alg_name, &crypto_aead_type, type, mask);
 275 }
 276 EXPORT_SYMBOL_GPL(crypto_has_aead);
 277
 278 static int aead_prepare_alg(struct aead_alg *alg)
 279 {
 280         struct crypto_istat_aead *istat = aead_get_stat(alg);
 281         struct crypto_alg *base = &alg->base;
 282
 283         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 284             PAGE_SIZE / 8)
 285                 return -EINVAL;
 286
 287         if (!alg->chunksize)
 288                 alg->chunksize = base->cra_blocksize;
 289
 290         base->cra_type = &crypto_aead_type;
 291         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 292         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 293
 294         if (IS_ENABLED(CONFIG_CRYPTO_STATS))
 295                 memset(istat, 0, sizeof(*istat));
 296
 297         return 0;
 298 }
 299
 300 int crypto_register_aead(struct aead_alg *alg)
 301 {
 302         struct crypto_alg *base = &alg->base;
 303         int err;
 304
 305         err = aead_prepare_alg(alg);
 306         if (err)
 307                 return err;
 308
 309         return crypto_register_alg(base);
 310 }
 311 EXPORT_SYMBOL_GPL(crypto_register_aead);
 312
 313 void crypto_unregister_aead(struct aead_alg *alg)
 314 {
 315         crypto_unregister_alg(&alg->base);
 316 }
 317 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 318
 319 int crypto_register_aeads(struct aead_alg *algs, int count)
 320 {
 321         int i, ret;
 322
 323         for (i = 0; i < count; i++) {
 324                 ret = crypto_register_aead(&algs[i]);
 325                 if (ret)
 326                         goto err;
 327         }
 328
 329         return 0;
 330
 331 err:
 332         for (--i; i >= 0; --i)
 333                 crypto_unregister_aead(&algs[i]);
 334
 335         return ret;
 336 }
 337 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 338
 339 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 340 {
 341         int i;
 342
 343         for (i = count - 1; i >= 0; --i)
 344                 crypto_unregister_aead(&algs[i]);
 345 }
 346 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 347
 348 int aead_register_instance(struct crypto_template *tmpl,
 349                            struct aead_instance *inst)
 350 {
 351         int err;
 352
 353         if (WARN_ON(!inst->free))
 354                 return -EINVAL;
 355
 356         err = aead_prepare_alg(&inst->alg);
 357         if (err)
 358                 return err;
 359
 360         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 361 }
 362 EXPORT_SYMBOL_GPL(aead_register_instance);
 363
 364 MODULE_LICENSE("GPL");
 365 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");