/*
   * Cryptographic API.
   *
   * RIPEMD-128 - RACE Integrity Primitives Evaluation Message Digest.
   *
   * Based on the reference implementation by Antoon Bosselaers, ESAT-COSIC
   *

   * Copyright (c) 2008 Adrian-Ken Rueegsegger <ken@codelabs.ch>

   *
   * 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 <crypto/internal/hash.h>

  #include <linux/init.h>
  #include <linux/module.h>
  #include <linux/mm.h>

  #include <linux/types.h>
  #include <asm/byteorder.h>
  
  #include "ripemd.h"
  
  struct rmd128_ctx {
  	u64 byte_count;
  	u32 state[4];

  	__le32 buffer[16];

  };

  #define K1  RMD_K1
  #define K2  RMD_K2
  #define K3  RMD_K3
  #define K4  RMD_K4
  #define KK1 RMD_K6
  #define KK2 RMD_K7
  #define KK3 RMD_K8
  #define KK4 RMD_K1

  
  #define F1(x, y, z) (x ^ y ^ z)		/* XOR */
  #define F2(x, y, z) (z ^ (x & (y ^ z)))	/* x ? y : z */
  #define F3(x, y, z) ((x | ~y) ^ z)
  #define F4(x, y, z) (y ^ (z & (x ^ y)))	/* z ? x : y */
  
  #define ROUND(a, b, c, d, f, k, x, s)  { \

  	(a) += f((b), (c), (d)) + le32_to_cpup(&(x)) + (k);	\

  	(a) = rol32((a), (s)); \
  }

  static void rmd128_transform(u32 *state, const __le32 *in)

  {
  	u32 aa, bb, cc, dd, aaa, bbb, ccc, ddd;
  
  	/* Initialize left lane */
  	aa = state[0];
  	bb = state[1];
  	cc = state[2];
  	dd = state[3];
  
  	/* Initialize right lane */
  	aaa = state[0];
  	bbb = state[1];
  	ccc = state[2];
  	ddd = state[3];
  
  	/* round 1: left lane */
  	ROUND(aa, bb, cc, dd, F1, K1, in[0],  11);
  	ROUND(dd, aa, bb, cc, F1, K1, in[1],  14);
  	ROUND(cc, dd, aa, bb, F1, K1, in[2],  15);
  	ROUND(bb, cc, dd, aa, F1, K1, in[3],  12);
  	ROUND(aa, bb, cc, dd, F1, K1, in[4],   5);
  	ROUND(dd, aa, bb, cc, F1, K1, in[5],   8);
  	ROUND(cc, dd, aa, bb, F1, K1, in[6],   7);
  	ROUND(bb, cc, dd, aa, F1, K1, in[7],   9);
  	ROUND(aa, bb, cc, dd, F1, K1, in[8],  11);
  	ROUND(dd, aa, bb, cc, F1, K1, in[9],  13);
  	ROUND(cc, dd, aa, bb, F1, K1, in[10], 14);
  	ROUND(bb, cc, dd, aa, F1, K1, in[11], 15);
  	ROUND(aa, bb, cc, dd, F1, K1, in[12],  6);
  	ROUND(dd, aa, bb, cc, F1, K1, in[13],  7);
  	ROUND(cc, dd, aa, bb, F1, K1, in[14],  9);
  	ROUND(bb, cc, dd, aa, F1, K1, in[15],  8);
  
  	/* round 2: left lane */
  	ROUND(aa, bb, cc, dd, F2, K2, in[7],   7);
  	ROUND(dd, aa, bb, cc, F2, K2, in[4],   6);
  	ROUND(cc, dd, aa, bb, F2, K2, in[13],  8);
  	ROUND(bb, cc, dd, aa, F2, K2, in[1],  13);
  	ROUND(aa, bb, cc, dd, F2, K2, in[10], 11);
  	ROUND(dd, aa, bb, cc, F2, K2, in[6],   9);
  	ROUND(cc, dd, aa, bb, F2, K2, in[15],  7);
  	ROUND(bb, cc, dd, aa, F2, K2, in[3],  15);
  	ROUND(aa, bb, cc, dd, F2, K2, in[12],  7);
  	ROUND(dd, aa, bb, cc, F2, K2, in[0],  12);
  	ROUND(cc, dd, aa, bb, F2, K2, in[9],  15);
  	ROUND(bb, cc, dd, aa, F2, K2, in[5],   9);
  	ROUND(aa, bb, cc, dd, F2, K2, in[2],  11);
  	ROUND(dd, aa, bb, cc, F2, K2, in[14],  7);
  	ROUND(cc, dd, aa, bb, F2, K2, in[11], 13);
  	ROUND(bb, cc, dd, aa, F2, K2, in[8],  12);
  
  	/* round 3: left lane */
  	ROUND(aa, bb, cc, dd, F3, K3, in[3],  11);
  	ROUND(dd, aa, bb, cc, F3, K3, in[10], 13);
  	ROUND(cc, dd, aa, bb, F3, K3, in[14],  6);
  	ROUND(bb, cc, dd, aa, F3, K3, in[4],   7);
  	ROUND(aa, bb, cc, dd, F3, K3, in[9],  14);
  	ROUND(dd, aa, bb, cc, F3, K3, in[15],  9);
  	ROUND(cc, dd, aa, bb, F3, K3, in[8],  13);
  	ROUND(bb, cc, dd, aa, F3, K3, in[1],  15);
  	ROUND(aa, bb, cc, dd, F3, K3, in[2],  14);
  	ROUND(dd, aa, bb, cc, F3, K3, in[7],   8);
  	ROUND(cc, dd, aa, bb, F3, K3, in[0],  13);
  	ROUND(bb, cc, dd, aa, F3, K3, in[6],   6);
  	ROUND(aa, bb, cc, dd, F3, K3, in[13],  5);
  	ROUND(dd, aa, bb, cc, F3, K3, in[11], 12);
  	ROUND(cc, dd, aa, bb, F3, K3, in[5],   7);
  	ROUND(bb, cc, dd, aa, F3, K3, in[12],  5);
  
  	/* round 4: left lane */
  	ROUND(aa, bb, cc, dd, F4, K4, in[1],  11);
  	ROUND(dd, aa, bb, cc, F4, K4, in[9],  12);
  	ROUND(cc, dd, aa, bb, F4, K4, in[11], 14);
  	ROUND(bb, cc, dd, aa, F4, K4, in[10], 15);
  	ROUND(aa, bb, cc, dd, F4, K4, in[0],  14);
  	ROUND(dd, aa, bb, cc, F4, K4, in[8],  15);
  	ROUND(cc, dd, aa, bb, F4, K4, in[12],  9);
  	ROUND(bb, cc, dd, aa, F4, K4, in[4],   8);
  	ROUND(aa, bb, cc, dd, F4, K4, in[13],  9);
  	ROUND(dd, aa, bb, cc, F4, K4, in[3],  14);
  	ROUND(cc, dd, aa, bb, F4, K4, in[7],   5);
  	ROUND(bb, cc, dd, aa, F4, K4, in[15],  6);
  	ROUND(aa, bb, cc, dd, F4, K4, in[14],  8);
  	ROUND(dd, aa, bb, cc, F4, K4, in[5],   6);
  	ROUND(cc, dd, aa, bb, F4, K4, in[6],   5);
  	ROUND(bb, cc, dd, aa, F4, K4, in[2],  12);
  
  	/* round 1: right lane */
  	ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[5],   8);
  	ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[14],  9);
  	ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[7],   9);
  	ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[0],  11);
  	ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[9],  13);
  	ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[2],  15);
  	ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[11], 15);
  	ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[4],   5);
  	ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[13],  7);
  	ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[6],   7);
  	ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[15],  8);
  	ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[8],  11);
  	ROUND(aaa, bbb, ccc, ddd, F4, KK1, in[1],  14);
  	ROUND(ddd, aaa, bbb, ccc, F4, KK1, in[10], 14);
  	ROUND(ccc, ddd, aaa, bbb, F4, KK1, in[3],  12);
  	ROUND(bbb, ccc, ddd, aaa, F4, KK1, in[12],  6);
  
  	/* round 2: right lane */
  	ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[6],   9);
  	ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[11], 13);
  	ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[3],  15);
  	ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[7],   7);
  	ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[0],  12);
  	ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[13],  8);
  	ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[5],   9);
  	ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[10], 11);
  	ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[14],  7);
  	ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[15],  7);
  	ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[8],  12);
  	ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[12],  7);
  	ROUND(aaa, bbb, ccc, ddd, F3, KK2, in[4],   6);
  	ROUND(ddd, aaa, bbb, ccc, F3, KK2, in[9],  15);
  	ROUND(ccc, ddd, aaa, bbb, F3, KK2, in[1],  13);
  	ROUND(bbb, ccc, ddd, aaa, F3, KK2, in[2],  11);
  
  	/* round 3: right lane */
  	ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[15],  9);
  	ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[5],   7);
  	ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[1],  15);
  	ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[3],  11);
  	ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[7],   8);
  	ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[14],  6);
  	ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[6],   6);
  	ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[9],  14);
  	ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[11], 12);
  	ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[8],  13);
  	ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[12],  5);
  	ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[2],  14);
  	ROUND(aaa, bbb, ccc, ddd, F2, KK3, in[10], 13);
  	ROUND(ddd, aaa, bbb, ccc, F2, KK3, in[0],  13);
  	ROUND(ccc, ddd, aaa, bbb, F2, KK3, in[4],   7);
  	ROUND(bbb, ccc, ddd, aaa, F2, KK3, in[13],  5);
  
  	/* round 4: right lane */
  	ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[8],  15);
  	ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[6],   5);
  	ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[4],   8);
  	ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[1],  11);
  	ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[3],  14);
  	ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[11], 14);
  	ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[15],  6);
  	ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[0],  14);
  	ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[5],   6);
  	ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[12],  9);
  	ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[2],  12);
  	ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[13],  9);
  	ROUND(aaa, bbb, ccc, ddd, F1, KK4, in[9],  12);
  	ROUND(ddd, aaa, bbb, ccc, F1, KK4, in[7],   5);
  	ROUND(ccc, ddd, aaa, bbb, F1, KK4, in[10], 15);
  	ROUND(bbb, ccc, ddd, aaa, F1, KK4, in[14],  8);
  
  	/* combine results */
  	ddd += cc + state[1];		/* final result for state[0] */
  	state[1] = state[2] + dd + aaa;
  	state[2] = state[3] + aa + bbb;
  	state[3] = state[0] + bb + ccc;
  	state[0] = ddd;

  }

  static int rmd128_init(struct shash_desc *desc)

  {

  	struct rmd128_ctx *rctx = shash_desc_ctx(desc);

  
  	rctx->byte_count = 0;
  
  	rctx->state[0] = RMD_H0;
  	rctx->state[1] = RMD_H1;
  	rctx->state[2] = RMD_H2;
  	rctx->state[3] = RMD_H3;
  
  	memset(rctx->buffer, 0, sizeof(rctx->buffer));

  
  	return 0;

  }

  static int rmd128_update(struct shash_desc *desc, const u8 *data,
  			 unsigned int len)

  {

  	struct rmd128_ctx *rctx = shash_desc_ctx(desc);

  	const u32 avail = sizeof(rctx->buffer) - (rctx->byte_count & 0x3f);
  
  	rctx->byte_count += len;
  
  	/* Enough space in buffer? If so copy and we're done */
  	if (avail > len) {
  		memcpy((char *)rctx->buffer + (sizeof(rctx->buffer) - avail),
  		       data, len);

  		goto out;

  	}
  
  	memcpy((char *)rctx->buffer + (sizeof(rctx->buffer) - avail),
  	       data, avail);

  	rmd128_transform(rctx->state, rctx->buffer);

  	data += avail;
  	len -= avail;
  
  	while (len >= sizeof(rctx->buffer)) {
  		memcpy(rctx->buffer, data, sizeof(rctx->buffer));

  		rmd128_transform(rctx->state, rctx->buffer);

  		data += sizeof(rctx->buffer);
  		len -= sizeof(rctx->buffer);
  	}
  
  	memcpy(rctx->buffer, data, len);

  
  out:
  	return 0;

  }
  
  /* Add padding and return the message digest. */

  static int rmd128_final(struct shash_desc *desc, u8 *out)

  {

  	struct rmd128_ctx *rctx = shash_desc_ctx(desc);

  	u32 i, index, padlen;

  	__le64 bits;
  	__le32 *dst = (__le32 *)out;

  	static const u8 padding[64] = { 0x80, };

  
  	bits = cpu_to_le64(rctx->byte_count << 3);

  
  	/* Pad out to 56 mod 64 */
  	index = rctx->byte_count & 0x3f;
  	padlen = (index < 56) ? (56 - index) : ((64+56) - index);

  	rmd128_update(desc, padding, padlen);

  
  	/* Append length */

  	rmd128_update(desc, (const u8 *)&bits, sizeof(bits));

  
  	/* Store state in digest */

  	for (i = 0; i < 4; i++)

  		dst[i] = cpu_to_le32p(&rctx->state[i]);

  
  	/* Wipe context */
  	memset(rctx, 0, sizeof(*rctx));

  
  	return 0;

  }

  static struct shash_alg alg = {
  	.digestsize	=	RMD128_DIGEST_SIZE,
  	.init		=	rmd128_init,
  	.update		=	rmd128_update,
  	.final		=	rmd128_final,
  	.descsize	=	sizeof(struct rmd128_ctx),
  	.base		=	{
  		.cra_name	 =	"rmd128",

  		.cra_blocksize	 =	RMD128_BLOCK_SIZE,
  		.cra_module	 =	THIS_MODULE,
  	}

  };
  
  static int __init rmd128_mod_init(void)
  {

  	return crypto_register_shash(&alg);

  }
  
  static void __exit rmd128_mod_fini(void)
  {

  	crypto_unregister_shash(&alg);

  }
  
  module_init(rmd128_mod_init);
  module_exit(rmd128_mod_fini);
  
  MODULE_LICENSE("GPL");

  MODULE_AUTHOR("Adrian-Ken Rueegsegger <ken@codelabs.ch>");

  MODULE_DESCRIPTION("RIPEMD-128 Message Digest");

  MODULE_ALIAS_CRYPTO("rmd128");