// SPDX-License-Identifier: GPL-2.0-or-later

  /*
   * AEAD: Authenticated Encryption with Associated Data

   *

   * This file provides API support for AEAD algorithms.
   *

   * Copyright (c) 2007-2015 Herbert Xu <herbert@gondor.apana.org.au>

   */

  #include <crypto/internal/aead.h>
  #include <linux/errno.h>

  #include <linux/init.h>
  #include <linux/kernel.h>
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/seq_file.h>

  #include <linux/cryptouser.h>
  #include <net/netlink.h>

  #include "internal.h"

  static int setkey_unaligned(struct crypto_aead *tfm, const u8 *key,
  			    unsigned int keylen)
  {

  	unsigned long alignmask = crypto_aead_alignmask(tfm);
  	int ret;
  	u8 *buffer, *alignbuffer;
  	unsigned long absize;
  
  	absize = keylen + alignmask;
  	buffer = kmalloc(absize, GFP_ATOMIC);
  	if (!buffer)
  		return -ENOMEM;
  
  	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  	memcpy(alignbuffer, key, keylen);

  	ret = crypto_aead_alg(tfm)->setkey(tfm, alignbuffer, keylen);

  	memset(alignbuffer, 0, keylen);
  	kfree(buffer);
  	return ret;
  }

  int crypto_aead_setkey(struct crypto_aead *tfm,
  		       const u8 *key, unsigned int keylen)

  {

  	unsigned long alignmask = crypto_aead_alignmask(tfm);

  	int err;

  
  	if ((unsigned long)key & alignmask)

  		err = setkey_unaligned(tfm, key, keylen);
  	else
  		err = crypto_aead_alg(tfm)->setkey(tfm, key, keylen);

  	if (unlikely(err)) {
  		crypto_aead_set_flags(tfm, CRYPTO_TFM_NEED_KEY);

  		return err;

  	}

  	crypto_aead_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
  	return 0;

  }

  EXPORT_SYMBOL_GPL(crypto_aead_setkey);

  int crypto_aead_setauthsize(struct crypto_aead *tfm, unsigned int authsize)
  {
  	int err;

  	if ((!authsize && crypto_aead_maxauthsize(tfm)) ||
  	    authsize > crypto_aead_maxauthsize(tfm))

  		return -EINVAL;

  	if (crypto_aead_alg(tfm)->setauthsize) {
  		err = crypto_aead_alg(tfm)->setauthsize(tfm, authsize);

  		if (err)
  			return err;
  	}

  	tfm->authsize = authsize;

  	return 0;
  }
  EXPORT_SYMBOL_GPL(crypto_aead_setauthsize);

  int crypto_aead_encrypt(struct aead_request *req)
  {
  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
  	struct crypto_alg *alg = aead->base.__crt_alg;
  	unsigned int cryptlen = req->cryptlen;
  	int ret;
  
  	crypto_stats_get(alg);
  	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
  		ret = -ENOKEY;
  	else
  		ret = crypto_aead_alg(aead)->encrypt(req);
  	crypto_stats_aead_encrypt(cryptlen, alg, ret);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(crypto_aead_encrypt);
  
  int crypto_aead_decrypt(struct aead_request *req)
  {
  	struct crypto_aead *aead = crypto_aead_reqtfm(req);
  	struct crypto_alg *alg = aead->base.__crt_alg;
  	unsigned int cryptlen = req->cryptlen;
  	int ret;
  
  	crypto_stats_get(alg);
  	if (crypto_aead_get_flags(aead) & CRYPTO_TFM_NEED_KEY)
  		ret = -ENOKEY;
  	else if (req->cryptlen < crypto_aead_authsize(aead))
  		ret = -EINVAL;
  	else
  		ret = crypto_aead_alg(aead)->decrypt(req);
  	crypto_stats_aead_decrypt(cryptlen, alg, ret);
  	return ret;
  }
  EXPORT_SYMBOL_GPL(crypto_aead_decrypt);

  static void crypto_aead_exit_tfm(struct crypto_tfm *tfm)
  {
  	struct crypto_aead *aead = __crypto_aead_cast(tfm);
  	struct aead_alg *alg = crypto_aead_alg(aead);
  
  	alg->exit(aead);
  }

  static int crypto_aead_init_tfm(struct crypto_tfm *tfm)
  {
  	struct crypto_aead *aead = __crypto_aead_cast(tfm);
  	struct aead_alg *alg = crypto_aead_alg(aead);

  	crypto_aead_set_flags(aead, CRYPTO_TFM_NEED_KEY);

  	aead->authsize = alg->maxauthsize;

  	if (alg->exit)
  		aead->base.exit = crypto_aead_exit_tfm;
  
  	if (alg->init)
  		return alg->init(aead);

  	return 0;
  }

  #ifdef CONFIG_NET

  static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
  {
  	struct crypto_report_aead raead;
  	struct aead_alg *aead = container_of(alg, struct aead_alg, base);

  	memset(&raead, 0, sizeof(raead));
  
  	strscpy(raead.type, "aead", sizeof(raead.type));
  	strscpy(raead.geniv, "<none>", sizeof(raead.geniv));

  
  	raead.blocksize = alg->cra_blocksize;
  	raead.maxauthsize = aead->maxauthsize;
  	raead.ivsize = aead->ivsize;

  	return nla_put(skb, CRYPTOCFGA_REPORT_AEAD, sizeof(raead), &raead);

  }
  #else
  static int crypto_aead_report(struct sk_buff *skb, struct crypto_alg *alg)
  {
  	return -ENOSYS;
  }
  #endif
  
  static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)

  	__maybe_unused;

  static void crypto_aead_show(struct seq_file *m, struct crypto_alg *alg)
  {
  	struct aead_alg *aead = container_of(alg, struct aead_alg, base);
  
  	seq_printf(m, "type         : aead
  ");
  	seq_printf(m, "async        : %s
  ", alg->cra_flags & CRYPTO_ALG_ASYNC ?
  					     "yes" : "no");
  	seq_printf(m, "blocksize    : %u
  ", alg->cra_blocksize);
  	seq_printf(m, "ivsize       : %u
  ", aead->ivsize);
  	seq_printf(m, "maxauthsize  : %u
  ", aead->maxauthsize);
  	seq_printf(m, "geniv        : <none>
  ");
  }

  static void crypto_aead_free_instance(struct crypto_instance *inst)
  {
  	struct aead_instance *aead = aead_instance(inst);

  	aead->free(aead);
  }

  static const struct crypto_type crypto_aead_type = {

  	.extsize = crypto_alg_extsize,
  	.init_tfm = crypto_aead_init_tfm,

  	.free = crypto_aead_free_instance,

  #ifdef CONFIG_PROC_FS
  	.show = crypto_aead_show,
  #endif
  	.report = crypto_aead_report,
  	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
  	.maskset = CRYPTO_ALG_TYPE_MASK,
  	.type = CRYPTO_ALG_TYPE_AEAD,
  	.tfmsize = offsetof(struct crypto_aead, base),
  };

  int crypto_grab_aead(struct crypto_aead_spawn *spawn,
  		     struct crypto_instance *inst,
  		     const char *name, u32 type, u32 mask)

  {

  	spawn->base.frontend = &crypto_aead_type;

  	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);

  }
  EXPORT_SYMBOL_GPL(crypto_grab_aead);
  
  struct crypto_aead *crypto_alloc_aead(const char *alg_name, u32 type, u32 mask)
  {

  	return crypto_alloc_tfm(alg_name, &crypto_aead_type, type, mask);

  }
  EXPORT_SYMBOL_GPL(crypto_alloc_aead);

  static int aead_prepare_alg(struct aead_alg *alg)
  {
  	struct crypto_alg *base = &alg->base;

  	if (max3(alg->maxauthsize, alg->ivsize, alg->chunksize) >
  	    PAGE_SIZE / 8)

  		return -EINVAL;

  	if (!alg->chunksize)
  		alg->chunksize = base->cra_blocksize;

  	base->cra_type = &crypto_aead_type;

  	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
  	base->cra_flags |= CRYPTO_ALG_TYPE_AEAD;
  
  	return 0;
  }
  
  int crypto_register_aead(struct aead_alg *alg)
  {
  	struct crypto_alg *base = &alg->base;
  	int err;
  
  	err = aead_prepare_alg(alg);
  	if (err)
  		return err;
  
  	return crypto_register_alg(base);
  }
  EXPORT_SYMBOL_GPL(crypto_register_aead);

  void crypto_unregister_aead(struct aead_alg *alg)

  {

  	crypto_unregister_alg(&alg->base);

  }
  EXPORT_SYMBOL_GPL(crypto_unregister_aead);

  int crypto_register_aeads(struct aead_alg *algs, int count)
  {
  	int i, ret;
  
  	for (i = 0; i < count; i++) {
  		ret = crypto_register_aead(&algs[i]);
  		if (ret)
  			goto err;
  	}
  
  	return 0;
  
  err:
  	for (--i; i >= 0; --i)
  		crypto_unregister_aead(&algs[i]);
  
  	return ret;
  }
  EXPORT_SYMBOL_GPL(crypto_register_aeads);
  
  void crypto_unregister_aeads(struct aead_alg *algs, int count)
  {
  	int i;
  
  	for (i = count - 1; i >= 0; --i)
  		crypto_unregister_aead(&algs[i]);
  }
  EXPORT_SYMBOL_GPL(crypto_unregister_aeads);

  int aead_register_instance(struct crypto_template *tmpl,
  			   struct aead_instance *inst)
  {
  	int err;

  	if (WARN_ON(!inst->free))
  		return -EINVAL;

  	err = aead_prepare_alg(&inst->alg);
  	if (err)
  		return err;
  
  	return crypto_register_instance(tmpl, aead_crypto_instance(inst));
  }
  EXPORT_SYMBOL_GPL(aead_register_instance);

  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Authenticated Encryption with Associated Data (AEAD)");