linux/crypto/aead.c
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   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
  22static 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
  43int 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}
  62EXPORT_SYMBOL_GPL(crypto_aead_setkey);
  63
  64int 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}
  81EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);
  82
  83int 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}
  98EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
  99
 100int 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}
 117EXPORT_SYMBOL_GPL(crypto_aead_decrypt);
 118
 119static 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
 127static 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
 146static 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
 163static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
 164{
 165        return -ENOSYS;
 166}
 167#endif
 168
 169static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
 170        __maybe_unused;
 171static 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
 184static void crypto_aead_free_instance(struct crypto_instance *inst)
 185{
 186        struct aead_instance *aead = aead_instance(inst);
 187
 188        aead->free(aead);
 189}
 190
 191static const struct crypto_type crypto_aead_type = {
 192        .extsize = crypto_alg_extsize,
 193        .init_tfm = crypto_aead_init_tfm,
 194        .free = crypto_aead_free_instance,
 195#ifdef CONFIG_PROC_FS
 196        .show = crypto_aead_show,
 197#endif
 198        .report = crypto_aead_report,
 199        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
 200        .maskset = CRYPTO_ALG_TYPE_MASK,
 201        .type = CRYPTO_ALG_TYPE_AEAD,
 202        .tfmsize = offsetof(struct crypto_aead, base),
 203};
 204
 205int crypto_grab_aead(struct crypto_aead_spawn *spawn,
 206                     struct crypto_instance *inst,
 207                     const char *name, u32 type, u32 mask)
 208{
 209        spawn->base.frontend = &crypto_aead_type;
 210        return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
 211}
 212EXPORT_SYMBOL_GPL(crypto_grab_aead);
 213
 214struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
 215{
 216        return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);
 217}
 218EXPORT_SYMBOL_GPL(crypto_alloc_aead);
 219
 220static int aead_prepare_alg(struct aead_alg *alg)
 221{
 222        struct crypto_alg *base = &alg->base;
 223
 224        if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
 225            PAGE_SIZE / 8)
 226                return -EINVAL;
 227
 228        if (!alg->chunksize)
 229                alg->chunksize = base->cra_blocksize;
 230
 231        base->cra_type = &crypto_aead_type;
 232        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
 233        base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
 234
 235        return 0;
 236}
 237
 238int crypto_register_aead(struct aead_alg *alg)
 239{
 240        struct crypto_alg *base = &alg->base;
 241        int err;
 242
 243        err = aead_prepare_alg(alg);
 244        if (err)
 245                return err;
 246
 247        return crypto_register_alg(base);
 248}
 249EXPORT_SYMBOL_GPL(crypto_register_aead);
 250
 251void crypto_unregister_aead(struct aead_alg *alg)
 252{
 253        crypto_unregister_alg(&alg->base);
 254}
 255EXPORT_SYMBOL_GPL(crypto_unregister_aead);
 256
 257int crypto_register_aeads(struct aead_alg *algs, int count)
 258{
 259        int i, ret;
 260
 261        for (i = 0; i < count; i++) {
 262                ret = crypto_register_aead(&algs[i]);
 263                if (ret)
 264                        goto err;
 265        }
 266
 267        return 0;
 268
 269err:
 270        for (--i; i >= 0; --i)
 271                crypto_unregister_aead(&algs[i]);
 272
 273        return ret;
 274}
 275EXPORT_SYMBOL_GPL(crypto_register_aeads);
 276
 277void crypto_unregister_aeads(struct aead_alg *algs, int count)
 278{
 279        int i;
 280
 281        for (i = count - 1; i >= 0; --i)
 282                crypto_unregister_aead(&algs[i]);
 283}
 284EXPORT_SYMBOL_GPL(crypto_unregister_aeads);
 285
 286int aead_register_instance(struct crypto_template *tmpl,
 287                           struct aead_instance *inst)
 288{
 289        int err;
 290
 291        if (WARN_ON(!inst->free))
 292                return -EINVAL;
 293
 294        err = aead_prepare_alg(&inst->alg);
 295        if (err)
 296                return err;
 297
 298        return crypto_register_instance(tmpl, aead_crypto_instance(inst));
 299}
 300EXPORT_SYMBOL_GPL(aead_register_instance);
 301
 302MODULE_LICENSE("GPL");
 303MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");
 304
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