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

  /*
   * Cryptographic API.
   *
   * Cipher operations.
   *
   * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>

   * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>

   */

  #include <crypto/algapi.h>

  #include <linux/kernel.h>
  #include <linux/crypto.h>
  #include <linux/errno.h>

  #include <linux/slab.h>

  #include <linux/string.h>

  #include "internal.h"

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

  {
  	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;
  	unsigned long alignmask = crypto_tfm_alg_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 = cia->cia_setkey(tfm, alignbuffer, keylen);

  	memset(alignbuffer, 0, keylen);

  	kfree(buffer);
  	return ret;
  
  }

  static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
  {
  	struct cipher_alg *cia = &tfm->__crt_alg->cra_cipher;

  	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);

  	tfm->crt_flags &= ~CRYPTO_TFM_RES_MASK;

  	if (keylen < cia->cia_min_keysize || keylen > cia->cia_max_keysize) {
  		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
  		return -EINVAL;

  	}
  
  	if ((unsigned long)key & alignmask)
  		return setkey_unaligned(tfm, key, keylen);
  
  	return cia->cia_setkey(tfm, key, keylen);

  }

  static void cipher_crypt_unaligned(void (*fn)(struct crypto_tfm *, u8 *,
  					      const u8 *),
  				   struct crypto_tfm *tfm,
  				   u8 *dst, const u8 *src)
  {
  	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  	unsigned int size = crypto_tfm_alg_blocksize(tfm);

  	u8 buffer[MAX_CIPHER_BLOCKSIZE + MAX_CIPHER_ALIGNMASK];

  	u8 *tmp = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
  
  	memcpy(tmp, src, size);
  	fn(tfm, tmp, tmp);
  	memcpy(dst, tmp, size);
  }
  
  static void cipher_encrypt_unaligned(struct crypto_tfm *tfm,
  				     u8 *dst, const u8 *src)
  {
  	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
  
  	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
  		cipher_crypt_unaligned(cipher->cia_encrypt, tfm, dst, src);
  		return;
  	}
  
  	cipher->cia_encrypt(tfm, dst, src);
  }
  
  static void cipher_decrypt_unaligned(struct crypto_tfm *tfm,
  				     u8 *dst, const u8 *src)
  {
  	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
  	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;
  
  	if (unlikely(((unsigned long)dst | (unsigned long)src) & alignmask)) {
  		cipher_crypt_unaligned(cipher->cia_decrypt, tfm, dst, src);
  		return;
  	}
  
  	cipher->cia_decrypt(tfm, dst, src);
  }

  int crypto_init_cipher_ops(struct crypto_tfm *tfm)
  {

  	struct cipher_tfm *ops = &tfm->crt_cipher;

  	struct cipher_alg *cipher = &tfm->__crt_alg->cra_cipher;

  
  	ops->cit_setkey = setkey;

  	ops->cit_encrypt_one = crypto_tfm_alg_alignmask(tfm) ?
  		cipher_encrypt_unaligned : cipher->cia_encrypt;
  	ops->cit_decrypt_one = crypto_tfm_alg_alignmask(tfm) ?
  		cipher_decrypt_unaligned : cipher->cia_decrypt;

  	return 0;

  }