/*

   * Cryptographic API.
   *
   * Blowfish Cipher Algorithm, by Bruce Schneier.
   * http://www.counterpane.com/blowfish.html
   *
   * Adapted from Kerneli implementation.
   *
   * Copyright (c) Herbert Valerio Riedel <hvr@hvrlab.org>
   * Copyright (c) Kyle McMartin <kyle@debian.org>
   * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   */
  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/mm.h>

  #include <asm/byteorder.h>

  #include <linux/crypto.h>

  #include <linux/types.h>

  #include <crypto/blowfish.h>

  /*

   * Round loop unrolling macros, S is a pointer to a S-Box array
   * organized in 4 unsigned longs at a row.
   */
  #define GET32_3(x) (((x) & 0xff))
  #define GET32_2(x) (((x) >> (8)) & (0xff))
  #define GET32_1(x) (((x) >> (16)) & (0xff))
  #define GET32_0(x) (((x) >> (24)) & (0xff))
  
  #define bf_F(x) (((S[GET32_0(x)] + S[256 + GET32_1(x)]) ^ \

  		S[512 + GET32_2(x)]) + S[768 + GET32_3(x)])

  #define ROUND(a, b, n) ({ b ^= P[n]; a ^= bf_F(b); })

  static void bf_encrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)

  {

  	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);
  	const __be32 *in_blk = (const __be32 *)src;
  	__be32 *const out_blk = (__be32 *)dst;
  	const u32 *P = ctx->p;
  	const u32 *S = ctx->s;
  	u32 yl = be32_to_cpu(in_blk[0]);
  	u32 yr = be32_to_cpu(in_blk[1]);

  
  	ROUND(yr, yl, 0);
  	ROUND(yl, yr, 1);
  	ROUND(yr, yl, 2);
  	ROUND(yl, yr, 3);
  	ROUND(yr, yl, 4);
  	ROUND(yl, yr, 5);
  	ROUND(yr, yl, 6);
  	ROUND(yl, yr, 7);
  	ROUND(yr, yl, 8);
  	ROUND(yl, yr, 9);
  	ROUND(yr, yl, 10);
  	ROUND(yl, yr, 11);
  	ROUND(yr, yl, 12);
  	ROUND(yl, yr, 13);
  	ROUND(yr, yl, 14);
  	ROUND(yl, yr, 15);
  
  	yl ^= P[16];
  	yr ^= P[17];

  	out_blk[0] = cpu_to_be32(yr);
  	out_blk[1] = cpu_to_be32(yl);

  }

  static void bf_decrypt(struct crypto_tfm *tfm, u8 *dst, const u8 *src)

  {

  	struct bf_ctx *ctx = crypto_tfm_ctx(tfm);

  	const __be32 *in_blk = (const __be32 *)src;
  	__be32 *const out_blk = (__be32 *)dst;

  	const u32 *P = ctx->p;
  	const u32 *S = ctx->s;

  	u32 yl = be32_to_cpu(in_blk[0]);
  	u32 yr = be32_to_cpu(in_blk[1]);
  
  	ROUND(yr, yl, 17);
  	ROUND(yl, yr, 16);
  	ROUND(yr, yl, 15);
  	ROUND(yl, yr, 14);
  	ROUND(yr, yl, 13);
  	ROUND(yl, yr, 12);
  	ROUND(yr, yl, 11);
  	ROUND(yl, yr, 10);
  	ROUND(yr, yl, 9);
  	ROUND(yl, yr, 8);
  	ROUND(yr, yl, 7);
  	ROUND(yl, yr, 6);
  	ROUND(yr, yl, 5);
  	ROUND(yl, yr, 4);
  	ROUND(yr, yl, 3);
  	ROUND(yl, yr, 2);
  
  	yl ^= P[1];
  	yr ^= P[0];
  
  	out_blk[0] = cpu_to_be32(yr);
  	out_blk[1] = cpu_to_be32(yl);
  }

  static struct crypto_alg alg = {
  	.cra_name		=	"blowfish",

  	.cra_driver_name	=	"blowfish-generic",
  	.cra_priority		=	100,

  	.cra_flags		=	CRYPTO_ALG_TYPE_CIPHER,
  	.cra_blocksize		=	BF_BLOCK_SIZE,
  	.cra_ctxsize		=	sizeof(struct bf_ctx),

  	.cra_alignmask		=	3,

  	.cra_module		=	THIS_MODULE,
  	.cra_list		=	LIST_HEAD_INIT(alg.cra_list),
  	.cra_u			=	{ .cipher = {
  	.cia_min_keysize	=	BF_MIN_KEY_SIZE,
  	.cia_max_keysize	=	BF_MAX_KEY_SIZE,

  	.cia_setkey		=	blowfish_setkey,

  	.cia_encrypt		=	bf_encrypt,
  	.cia_decrypt		=	bf_decrypt } }

  };

  static int __init blowfish_mod_init(void)

  {
  	return crypto_register_alg(&alg);
  }

  static void __exit blowfish_mod_fini(void)

  {
  	crypto_unregister_alg(&alg);
  }

  module_init(blowfish_mod_init);
  module_exit(blowfish_mod_fini);

  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Blowfish Cipher Algorithm");

  MODULE_ALIAS("blowfish");