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kernel/linux-rt-4.4.41/arch/arm64/crypto/ghash-ce-glue.c 3.63 KB
5113f6f70   김현기   kernel add
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  /*
   * Accelerated GHASH implementation with ARMv8 PMULL instructions.
   *
   * Copyright (C) 2014 Linaro Ltd. <ard.biesheuvel@linaro.org>
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 as published
   * by the Free Software Foundation.
   */
  
  #include <asm/neon.h>
  #include <asm/unaligned.h>
  #include <crypto/internal/hash.h>
  #include <linux/cpufeature.h>
  #include <linux/crypto.h>
  #include <linux/module.h>
  
  MODULE_DESCRIPTION("GHASH secure hash using ARMv8 Crypto Extensions");
  MODULE_AUTHOR("Ard Biesheuvel <ard.biesheuvel@linaro.org>");
  MODULE_LICENSE("GPL v2");
  
  #define GHASH_BLOCK_SIZE	16
  #define GHASH_DIGEST_SIZE	16
  
  struct ghash_key {
  	u64 a;
  	u64 b;
  };
  
  struct ghash_desc_ctx {
  	u64 digest[GHASH_DIGEST_SIZE/sizeof(u64)];
  	u8 buf[GHASH_BLOCK_SIZE];
  	u32 count;
  };
  
  asmlinkage void pmull_ghash_update(int blocks, u64 dg[], const char *src,
  				   struct ghash_key const *k, const char *head);
  
  static int ghash_init(struct shash_desc *desc)
  {
  	struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  
  	*ctx = (struct ghash_desc_ctx){};
  	return 0;
  }
  
  static int ghash_update(struct shash_desc *desc, const u8 *src,
  			unsigned int len)
  {
  	struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  	unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  
  	ctx->count += len;
  
  	if ((partial + len) >= GHASH_BLOCK_SIZE) {
  		struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  		int blocks;
  
  		if (partial) {
  			int p = GHASH_BLOCK_SIZE - partial;
  
  			memcpy(ctx->buf + partial, src, p);
  			src += p;
  			len -= p;
  		}
  
  		blocks = len / GHASH_BLOCK_SIZE;
  		len %= GHASH_BLOCK_SIZE;
  
  		kernel_neon_begin_partial(8);
  		pmull_ghash_update(blocks, ctx->digest, src, key,
  				   partial ? ctx->buf : NULL);
  		kernel_neon_end();
  		src += blocks * GHASH_BLOCK_SIZE;
  		partial = 0;
  	}
  	if (len)
  		memcpy(ctx->buf + partial, src, len);
  	return 0;
  }
  
  static int ghash_final(struct shash_desc *desc, u8 *dst)
  {
  	struct ghash_desc_ctx *ctx = shash_desc_ctx(desc);
  	unsigned int partial = ctx->count % GHASH_BLOCK_SIZE;
  
  	if (partial) {
  		struct ghash_key *key = crypto_shash_ctx(desc->tfm);
  
  		memset(ctx->buf + partial, 0, GHASH_BLOCK_SIZE - partial);
  
  		kernel_neon_begin_partial(8);
  		pmull_ghash_update(1, ctx->digest, ctx->buf, key, NULL);
  		kernel_neon_end();
  	}
  	put_unaligned_be64(ctx->digest[1], dst);
  	put_unaligned_be64(ctx->digest[0], dst + 8);
  
  	*ctx = (struct ghash_desc_ctx){};
  	return 0;
  }
  
  static int ghash_setkey(struct crypto_shash *tfm,
  			const u8 *inkey, unsigned int keylen)
  {
  	struct ghash_key *key = crypto_shash_ctx(tfm);
  	u64 a, b;
  
  	if (keylen != GHASH_BLOCK_SIZE) {
  		crypto_shash_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
  		return -EINVAL;
  	}
  
  	/* perform multiplication by 'x' in GF(2^128) */
  	b = get_unaligned_be64(inkey);
  	a = get_unaligned_be64(inkey + 8);
  
  	key->a = (a << 1) | (b >> 63);
  	key->b = (b << 1) | (a >> 63);
  
  	if (b >> 63)
  		key->b ^= 0xc200000000000000UL;
  
  	return 0;
  }
  
  static struct shash_alg ghash_alg = {
  	.digestsize	= GHASH_DIGEST_SIZE,
  	.init		= ghash_init,
  	.update		= ghash_update,
  	.final		= ghash_final,
  	.setkey		= ghash_setkey,
  	.descsize	= sizeof(struct ghash_desc_ctx),
  	.base		= {
  		.cra_name		= "ghash",
  		.cra_driver_name	= "ghash-ce",
  		.cra_priority		= 200,
  		.cra_flags		= CRYPTO_ALG_TYPE_SHASH,
  		.cra_blocksize		= GHASH_BLOCK_SIZE,
  		.cra_ctxsize		= sizeof(struct ghash_key),
  		.cra_module		= THIS_MODULE,
  	},
  };
  
  static int __init ghash_ce_mod_init(void)
  {
  	return crypto_register_shash(&ghash_alg);
  }
  
  static void __exit ghash_ce_mod_exit(void)
  {
  	crypto_unregister_shash(&ghash_alg);
  }
  
  module_cpu_feature_match(PMULL, ghash_ce_mod_init);
  module_exit(ghash_ce_mod_exit);