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 int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  24                             unsigned int keylen)
  25 {
  26         unsigned long alignmask = crypto_aead_alignmask(tfm);
  27         int ret;
  28         u8 *buffer, *alignbuffer;
  29         unsigned long absize;
  30
  31         absize = keylen + alignmask;
  32         buffer = kmalloc(absize, GFP_ATOMIC);
  33         if (!buffer)
  34                 return -ENOMEM;
  35
  36         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  37         memcpy(alignbuffer, key, keylen);
  38         ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
  39         kfree_sensitive(buffer);
  40         return ret;
  41 }
  42
  43 int crypto_aead_setkey(struct crypto_aead *tfm,
  44                        const u8 *key, unsigned int keylen)
  45 {
  46         unsigned long alignmask = crypto_aead_alignmask(tfm);
  47         int err;
  48
  49         if ((unsigned long)key & alignmask)
  50                 err = setkey_unaligned(tfm, key, keylen);
  51         else
  52                 err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);
  53
  54         if (unlikely(err)) {
  55                 crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
  56                 return err;
  57         }
  58
  59         crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  60         return 0;
  61 }
  62 EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  63
  64 int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  65 {
  66         int err;
  67
  68         if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
  69             authsize > crypto_aead_maxauthsize(tfm))
  70                 return -EINVAL;
  71
  72         if (crypto_aead_alg(tfm)->setauthsize) {
  73                 err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);
  74                 if (err)
  75                         return err;
  76         }
  77
  78         tfm->authsize = authsize;
  79         return 0;
  80 }
  81 EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  82
  83 int crypto_aead_encrypt(struct aead_request *req)
  84 {
  85         struct crypto_aead *aead = crypto_aead_reqtfm(req);
  86
  87         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
  88                 return -ENOKEY;
  89
  90         return crypto_aead_alg(aead)->encrypt(req);
  91 }
  92 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
  93
  94 int crypto_aead_decrypt(struct aead_request *req)
  95 {
  96         struct crypto_aead *aead = crypto_aead_reqtfm(req);
  97
  98         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
  99                 return -ENOKEY;
 100
 101         if (req->cryptlen < crypto_aead_authsize(aead))
 102                 return -EINVAL;
 103
 104         return crypto_aead_alg(aead)->decrypt(req);
 105 }
 106 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
 107
 108 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
 109 {
 110         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 111         struct aead_alg *alg = crypto_aead_alg(aead);
 112
 113         alg->exit(aead);
 114 }
 115
 116 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
 117 {
 118         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 119         struct aead_alg *alg = crypto_aead_alg(aead);
 120
 121         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 122
 123         aead->authsize = alg->maxauthsize;
 124
 125         if (alg->exit)
 126                 aead->base.exit = crypto_aead_exit_tfm;
 127
 128         if (alg->init)
 129                 return alg->init(aead);
 130
 131         return 0;
 132 }
 133
 134 static int __maybe_unused crypto_aead_report(
 135         struct sk_buff *skb, struct crypto_alg *alg)
 136 {
 137         struct crypto_report_aead raead;
 138         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 139
 140         memset(&raead, 0, sizeof(raead));
 141
 142         strscpy(raead.type, "aead", sizeof(raead.type));
 143         strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
 144
 145         raead.blocksize = alg->cra_blocksize;
 146         raead.maxauthsize = aead->maxauthsize;
 147         raead.ivsize = aead->ivsize;
 148
 149         return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
 150 }
 151
 152 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 153         __maybe_unused;
 154 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 155 {
 156         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 157
 158         seq_printf(m, "type         : aead\n");
 159         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 160                                              "yes" : "no");
 161         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 162         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 163         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 164         seq_printf(m, "geniv        : <none>\n");
 165 }
 166
 167 static void crypto_aead_free_instance(struct crypto_instance *inst)
 168 {
 169         struct aead_instance *aead = aead_instance(inst);
 170
 171         aead->free(aead);
 172 }
 173
 174 static const struct crypto_type crypto_aead_type = {
 175         .extsize = crypto_alg_extsize,
 176         .init_tfm = crypto_aead_init_tfm,
 177         .free = crypto_aead_free_instance,
 178 #ifdef CONFIG_PROC_FS
 179         .show = crypto_aead_show,
 180 #endif
 181 #if IS_ENABLED(CONFIG_CRYPTO_USER)
 182         .report = crypto_aead_report,
 183 #endif
 184         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 185         .maskset = CRYPTO_ALG_TYPE_MASK,
 186         .type = CRYPTO_ALG_TYPE_AEAD,
 187         .tfmsize = offsetof(struct crypto_aead, base),
 188 };
 189
 190 int crypto_grab_aead(struct crypto_aead_spawn *spawn,
 191                      struct crypto_instance *inst,
 192                      const char *name, u32 type, u32 mask)
 193 {
 194         spawn->base.frontend = &crypto_aead_type;
 195         return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 196 }
 197 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 198
 199 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 200 {
 201         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 202 }
 203 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 204
 205 int crypto_has_aead(const char *alg_name, u32 type, u32 mask)
 206 {
 207         return crypto_type_has_alg(alg_name, &crypto_aead_type, type, mask);
 208 }
 209 EXPORT_SYMBOL_GPL(crypto_has_aead);
 210
 211 static int aead_prepare_alg(struct aead_alg *alg)
 212 {
 213         struct crypto_alg *base = &alg->base;
 214
 215         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 216             PAGE_SIZE / 8)
 217                 return -EINVAL;
 218
 219         if (!alg->chunksize)
 220                 alg->chunksize = base->cra_blocksize;
 221
 222         base->cra_type = &crypto_aead_type;
 223         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 224         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 225
 226         return 0;
 227 }
 228
 229 int crypto_register_aead(struct aead_alg *alg)
 230 {
 231         struct crypto_alg *base = &alg->base;
 232         int err;
 233
 234         err = aead_prepare_alg(alg);
 235         if (err)
 236                 return err;
 237
 238         return crypto_register_alg(base);
 239 }
 240 EXPORT_SYMBOL_GPL(crypto_register_aead);
 241
 242 void crypto_unregister_aead(struct aead_alg *alg)
 243 {
 244         crypto_unregister_alg(&alg->base);
 245 }
 246 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 247
 248 int crypto_register_aeads(struct aead_alg *algs, int count)
 249 {
 250         int i, ret;
 251
 252         for (i = 0; i < count; i++) {
 253                 ret = crypto_register_aead(&algs[i]);
 254                 if (ret)
 255                         goto err;
 256         }
 257
 258         return 0;
 259
 260 err:
 261         for (--i; i >= 0; --i)
 262                 crypto_unregister_aead(&algs[i]);
 263
 264         return ret;
 265 }
 266 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 267
 268 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 269 {
 270         int i;
 271
 272         for (i = count - 1; i >= 0; --i)
 273                 crypto_unregister_aead(&algs[i]);
 274 }
 275 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 276
 277 int aead_register_instance(struct crypto_template *tmpl,
 278                            struct aead_instance *inst)
 279 {
 280         int err;
 281
 282         if (WARN_ON(!inst->free))
 283                 return -EINVAL;
 284
 285         err = aead_prepare_alg(&inst->alg);
 286         if (err)
 287                 return err;
 288
 289         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 290 }
 291 EXPORT_SYMBOL_GPL(aead_register_instance);
 292
 293 MODULE_LICENSE("GPL");
 294 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");