// SPDX-License-Identifier: GPL-2.0-only

  /*
   * Scalar fixed time AES core transform
   *
   * Copyright (C) 2017 Linaro Ltd <ard.biesheuvel@linaro.org>

   */
  
  #include <crypto/aes.h>
  #include <linux/crypto.h>
  #include <linux/module.h>

  
  static int aesti_set_key(struct crypto_tfm *tfm, const u8 *in_key,
  			 unsigned int key_len)
  {
  	struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

  	return aes_expandkey(ctx, in_key, key_len);

  }
  
  static void aesti_encrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  {
  	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

  	unsigned long flags;

  	/*
  	 * Temporarily disable interrupts to avoid races where cachelines are
  	 * evicted when the CPU is interrupted to do something else.
  	 */
  	local_irq_save(flags);

  	aes_encrypt(ctx, out, in);

  
  	local_irq_restore(flags);

  }
  
  static void aesti_decrypt(struct crypto_tfm *tfm, u8 *out, const u8 *in)
  {
  	const struct crypto_aes_ctx *ctx = crypto_tfm_ctx(tfm);

  	unsigned long flags;

  	/*
  	 * Temporarily disable interrupts to avoid races where cachelines are
  	 * evicted when the CPU is interrupted to do something else.
  	 */
  	local_irq_save(flags);

  	aes_decrypt(ctx, out, in);

  
  	local_irq_restore(flags);

  }
  
  static struct crypto_alg aes_alg = {
  	.cra_name			= "aes",
  	.cra_driver_name		= "aes-fixed-time",
  	.cra_priority			= 100 + 1,
  	.cra_flags			= CRYPTO_ALG_TYPE_CIPHER,
  	.cra_blocksize			= AES_BLOCK_SIZE,
  	.cra_ctxsize			= sizeof(struct crypto_aes_ctx),
  	.cra_module			= THIS_MODULE,
  
  	.cra_cipher.cia_min_keysize	= AES_MIN_KEY_SIZE,
  	.cra_cipher.cia_max_keysize	= AES_MAX_KEY_SIZE,
  	.cra_cipher.cia_setkey		= aesti_set_key,
  	.cra_cipher.cia_encrypt		= aesti_encrypt,
  	.cra_cipher.cia_decrypt		= aesti_decrypt
  };
  
  static int __init aes_init(void)
  {
  	return crypto_register_alg(&aes_alg);
  }
  
  static void __exit aes_fini(void)
  {
  	crypto_unregister_alg(&aes_alg);
  }
  
  module_init(aes_init);
  module_exit(aes_fini);
  
  MODULE_DESCRIPTION("Generic fixed time AES");
  MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  MODULE_LICENSE("GPL v2");