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/errno.h>
  12 #include <linux/init.h>
  13 #include <linux/kernel.h>
  14 #include <linux/module.h>
  15 #include <linux/slab.h>
  16 #include <linux/seq_file.h>
  17 #include <linux/cryptouser.h>
  18 #include <net/netlink.h>
  19
  20 #include "internal.h"
  21
  22 static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  23                             unsigned int keylen)
  24 {
  25         unsigned long alignmask = crypto_aead_alignmask(tfm);
  26         int ret;
  27         u8 *buffer, *alignbuffer;
  28         unsigned long absize;
  29
  30         absize = keylen + alignmask;
  31         buffer = kmalloc(absize, GFP_ATOMIC);
  32         if (!buffer)
  33                 return -ENOMEM;
  34
  35         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  36         memcpy(alignbuffer, key, keylen);
  37         ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);
  38         memset(alignbuffer, 0, keylen);
  39         kfree(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         struct crypto_alg *alg = aead->base.__crt_alg;
  87         unsigned int cryptlen = req->cryptlen;
  88         int ret;
  89
  90         crypto_stats_get(alg);
  91         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
  92                 ret = -ENOKEY;
  93         else
  94                 ret = crypto_aead_alg(aead)->encrypt(req);
  95         crypto_stats_aead_encrypt(cryptlen, alg, ret);
  96         return ret;
  97 }
  98 EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
  99
 100 int crypto_aead_decrypt(struct aead_request *req)
 101 {
 102         struct crypto_aead *aead = crypto_aead_reqtfm(req);
 103         struct crypto_alg *alg = aead->base.__crt_alg;
 104         unsigned int cryptlen = req->cryptlen;
 105         int ret;
 106
 107         crypto_stats_get(alg);
 108         if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
 109                 ret = -ENOKEY;
 110         else if (req->cryptlen < crypto_aead_authsize(aead))
 111                 ret = -EINVAL;
 112         else
 113                 ret = crypto_aead_alg(aead)->decrypt(req);
 114         crypto_stats_aead_decrypt(cryptlen, alg, ret);
 115         return ret;
 116 }
 117 EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
 118
 119 static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
 120 {
 121         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 122         struct aead_alg *alg = crypto_aead_alg(aead);
 123
 124         alg->exit(aead);
 125 }
 126
 127 static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
 128 {
 129         struct crypto_aead *aead = __crypto_aead_cast(tfm);
 130         struct aead_alg *alg = crypto_aead_alg(aead);
 131
 132         crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);
 133
 134         aead->authsize = alg->maxauthsize;
 135
 136         if (alg->exit)
 137                 aead->base.exit = crypto_aead_exit_tfm;
 138
 139         if (alg->init)
 140                 return alg->init(aead);
 141
 142         return 0;
 143 }
 144
 145 #ifdef CONFIG_NET
 146 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 147 {
 148         struct crypto_report_aead raead;
 149         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 150
 151         memset(&raead, 0, sizeof(raead));
 152
 153         strscpy(raead.type, "aead", sizeof(raead.type));
 154         strscpy(raead.geniv, "<none>", sizeof(raead.geniv));
 155
 156         raead.blocksize = alg->cra_blocksize;
 157         raead.maxauthsize = aead->maxauthsize;
 158         raead.ivsize = aead->ivsize;
 159
 160         return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);
 161 }
 162 #else
 163 static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 164 {
 165         return -ENOSYS;
 166 }
 167 #endif
 168
 169 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 170         __maybe_unused;
 171 static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 172 {
 173         struct aead_alg *aead = container_of(alg, struct aead_alg, base);
 174
 175         seq_printf(m, "type         : aead\n");
 176         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
 177                                              "yes" : "no");
 178         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
 179         seq_printf(m, "ivsize       : %u\n", aead->ivsize);
 180         seq_printf(m, "maxauthsize  : %u\n", aead->maxauthsize);
 181         seq_printf(m, "geniv        : <none>\n");
 182 }
 183
 184 static void crypto_aead_free_instance(struct crypto_instance *inst)
 185 {
 186         struct aead_instance *aead = aead_instance(inst);
 187
 188         if (!aead->free) {
 189                 inst->tmpl->free(inst);
 190                 return;
 191         }
 192
 193         aead->free(aead);
 194 }
 195
 196 static const struct crypto_type crypto_aead_type = {
 197         .extsize = crypto_alg_extsize,
 198         .init_tfm = crypto_aead_init_tfm,
 199         .free = crypto_aead_free_instance,
 200 #ifdef CONFIG_PROC_FS
 201         .show = crypto_aead_show,
 202 #endif
 203         .report = crypto_aead_report,
 204         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 205         .maskset = CRYPTO_ALG_TYPE_MASK,
 206         .type = CRYPTO_ALG_TYPE_AEAD,
 207         .tfmsize = offsetof(struct crypto_aead, base),
 208 };
 209
 210 int crypto_grab_aead(struct crypto_aead_spawn *spawn, const char *name,
 211                      u32 type, u32 mask)
 212 {
 213         spawn->base.frontend = &crypto_aead_type;
 214         return crypto_grab_spawn(&spawn->base, name, type, mask);
 215 }
 216 EXPORT_SYMBOL_GPL(crypto_grab_aead);
 217
 218 struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 219 {
 220         return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 221 }
 222 EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 223
 224 static int aead_prepare_alg(struct aead_alg *alg)
 225 {
 226         struct crypto_alg *base = &alg->base;
 227
 228         if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 229             PAGE_SIZE / 8)
 230                 return -EINVAL;
 231
 232         if (!alg->chunksize)
 233                 alg->chunksize = base->cra_blocksize;
 234
 235         base->cra_type = &crypto_aead_type;
 236         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 237         base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 238
 239         return 0;
 240 }
 241
 242 int crypto_register_aead(struct aead_alg *alg)
 243 {
 244         struct crypto_alg *base = &alg->base;
 245         int err;
 246
 247         err = aead_prepare_alg(alg);
 248         if (err)
 249                 return err;
 250
 251         return crypto_register_alg(base);
 252 }
 253 EXPORT_SYMBOL_GPL(crypto_register_aead);
 254
 255 void crypto_unregister_aead(struct aead_alg *alg)
 256 {
 257         crypto_unregister_alg(&alg->base);
 258 }
 259 EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 260
 261 int crypto_register_aeads(struct aead_alg *algs, int count)
 262 {
 263         int i, ret;
 264
 265         for (i = 0; i < count; i++) {
 266                 ret = crypto_register_aead(&algs[i]);
 267                 if (ret)
 268                         goto err;
 269         }
 270
 271         return 0;
 272
 273 err:
 274         for (--i; i >= 0; --i)
 275                 crypto_unregister_aead(&algs[i]);
 276
 277         return ret;
 278 }
 279 EXPORT_SYMBOL_GPL(crypto_register_aeads);
 280
 281 void crypto_unregister_aeads(struct aead_alg *algs, int count)
 282 {
 283         int i;
 284
 285         for (i = count - 1; i >= 0; --i)
 286                 crypto_unregister_aead(&algs[i]);
 287 }
 288 EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 289
 290 int aead_register_instance(struct crypto_template *tmpl,
 291                            struct aead_instance *inst)
 292 {
 293         int err;
 294
 295         err = aead_prepare_alg(&inst->alg);
 296         if (err)
 297                 return err;
 298
 299         return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 300 }
 301 EXPORT_SYMBOL_GPL(aead_register_instance);
 302
 303 MODULE_LICENSE("GPL");
 304 MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");