text: /* $OpenBSD: gostr341194.c,v 1.2 2014/11/09 23:06:52 miod Exp $ */
  /*
   * Copyright (c) 2014 Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>
   * Copyright (c) 2005-2006 Cryptocom LTD
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions
   * are met:
   *
   * 1. Redistributions of source code must retain the above copyright
   *    notice, this list of conditions and the following disclaimer.
   *
   * 2. Redistributions in binary form must reproduce the above copyright
   *    notice, this list of conditions and the following disclaimer in
   *    the documentation and/or other materials provided with the
   *    distribution.
   *
   * 3. All advertising materials mentioning features or use of this
   *    software must display the following acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
   *
   * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
   *    endorse or promote products derived from this software without
   *    prior written permission. For written permission, please contact
   *    openssl-core@openssl.org.
   *
   * 5. Products derived from this software may not be called "OpenSSL"
   *    nor may "OpenSSL" appear in their names without prior written
   *    permission of the OpenSSL Project.
   *
   * 6. Redistributions of any form whatsoever must retain the following
   *    acknowledgment:
   *    "This product includes software developed by the OpenSSL Project
   *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
   *
   * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
   * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
   * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
   * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
   * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
   * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
   * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
   * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
   * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
   * OF THE POSSIBILITY OF SUCH DAMAGE.
   * ====================================================================
   */
  
  #include <string.h>
  
  #include <openssl/opensslconf.h>
  
  #ifndef OPENSSL_NO_GOST
  #include <openssl/crypto.h>
  #include <openssl/objects.h>
  #include <openssl/gost.h>
  
  #include "gost_locl.h"
  
  /* Following functions are various bit meshing routines used in
   * GOST R 34.11-94 algorithms */
  static void
  swap_bytes(unsigned char *w, unsigned char *k)
  {
  	int i, j;
  
  	for (i = 0; i < 4; i++)
  		for (j = 0; j < 8; j++)
  			k[i + 4 * j] = w[8 * i + j];
  }
  
  /* was A_A */
  static void
  circle_xor8(const unsigned char *w, unsigned char *k)
  {
  	unsigned char buf[8];
  	int i;
  
  	memcpy(buf, w, 8);
  	memmove(k, w + 8, 24);
  	for (i = 0; i < 8; i++)
  		k[i + 24] = buf[i] ^ k[i];
  }
  
  /* was R_R */
  static void
  transform_3(unsigned char *data)
  {
  	unsigned short int acc;
  
  	acc = (data[0] ^ data[2] ^ data[4] ^ data[6] ^ data[24] ^ data[30]) |
  	     ((data[1] ^ data[3] ^ data[5] ^ data[7] ^ data[25] ^ data[31]) << 8);
  	memmove(data, data + 2, 30);
  	data[30] = acc & 0xff;
  	data[31] = acc >> 8;
  }
  
  /* Adds blocks of N bytes modulo 2**(8*n). Returns carry*/
  static int
  add_blocks(int n, unsigned char *left, const unsigned char *right)
  {
  	int i;
  	int carry = 0;
  	int sum;
  
  	for (i = 0; i < n; i++) {
  		sum = (int)left[i] + (int)right[i] + carry;
  		left[i] = sum & 0xff;
  		carry = sum >> 8;
  	}
  	return carry;
  }
  
  /* Xor two sequences of bytes */
  static void
  xor_blocks(unsigned char *result, const unsigned char *a,
      const unsigned char *b, size_t len)
  {
  	size_t i;
  
  	for (i = 0; i < len; i++)
  		result[i] = a[i] ^ b[i];
  }
  
  /* 
   * 	Calculate H(i+1) = Hash(Hi,Mi) 
   * 	Where H and M are 32 bytes long
   */
  static int
  hash_step(GOSTR341194_CTX *c, unsigned char *H, const unsigned char *M)
  {
  	unsigned char U[32], W[32], V[32], S[32], Key[32];
  	int i;
  
  	/* Compute first key */
  	xor_blocks(W, H, M, 32);
  	swap_bytes(W, Key);
  	/* Encrypt first 8 bytes of H with first key */
  	Gost2814789_set_key(&c->cipher, Key, 256);
  	Gost2814789_encrypt(H, S, &c->cipher);
  
  	/* Compute second key */
  	circle_xor8(H, U);
  	circle_xor8(M, V);
  	circle_xor8(V, V);
  	xor_blocks(W, U, V, 32);
  	swap_bytes(W, Key);
  	/* encrypt second 8 bytes of H with second key */
  	Gost2814789_set_key(&c->cipher, Key, 256);
  	Gost2814789_encrypt(H+8, S+8, &c->cipher);
  
  	/* compute third key */
  	circle_xor8(U, U);
  	U[31] = ~U[31];
  	U[29] = ~U[29];
  	U[28] = ~U[28];
  	U[24] = ~U[24];
  	U[23] = ~U[23];
  	U[20] = ~U[20];
  	U[18] = ~U[18];
  	U[17] = ~U[17];
  	U[14] = ~U[14];
  	U[12] = ~U[12];
  	U[10] = ~U[10];
  	U[8] = ~U[8];
  	U[7] = ~U[7];
  	U[5] = ~U[5];
  	U[3] = ~U[3];
  	U[1] = ~U[1];
  	circle_xor8(V, V);
  	circle_xor8(V, V);
  	xor_blocks(W, U, V, 32);
  	swap_bytes(W, Key);
  	/* encrypt third 8 bytes of H with third key */
  	Gost2814789_set_key(&c->cipher, Key, 256);
  	Gost2814789_encrypt(H+16, S+16, &c->cipher);
  
  	/* Compute fourth key */
  	circle_xor8(U, U);
  	circle_xor8(V, V);
  	circle_xor8(V, V);
  	xor_blocks(W, U, V, 32);
  	swap_bytes(W, Key);
  	/* Encrypt last 8 bytes with fourth key */
  	Gost2814789_set_key(&c->cipher, Key, 256);
  	Gost2814789_encrypt(H+24, S+24, &c->cipher);
  
  	for (i = 0; i < 12; i++)
  		transform_3(S);
  	xor_blocks(S, S, M, 32);
  	transform_3(S);
  	xor_blocks(S, S, H, 32);
  	for (i = 0; i < 61; i++)
  		transform_3(S);
  	memcpy(H, S, 32);
  	return 1;
  }
  
  int
  GOSTR341194_Init(GOSTR341194_CTX *c, int nid)
  {
  	memset(c, 0, sizeof(*c));
  	return Gost2814789_set_sbox(&c->cipher, nid);
  }
  
  static void
  GOSTR341194_block_data_order(GOSTR341194_CTX *ctx, const unsigned char *p,
      size_t num)
  {
  	int i;
  
  	for (i = 0; i < num; i++) {
  		hash_step(ctx, ctx->H, p);
  		add_blocks(32, ctx->S, p);
  		p += 32;
  	}
  }
  
  #define DATA_ORDER_IS_LITTLE_ENDIAN
  
  #define HASH_CBLOCK	GOSTR341194_CBLOCK
  #define HASH_LONG	GOSTR341194_LONG
  #define HASH_CTX	GOSTR341194_CTX
  #define HASH_UPDATE	GOSTR341194_Update
  #define HASH_TRANSFORM	GOSTR341194_Transform
  #define HASH_NO_FINAL	1
  #define HASH_BLOCK_DATA_ORDER	GOSTR341194_block_data_order
  
  #include "md32_common.h"
  
  int
  GOSTR341194_Final(unsigned char *md, GOSTR341194_CTX * c)
  {
  	unsigned char *p = (unsigned char *)c->data;
  	unsigned char T[32];
  
  	if (c->num > 0) {
  		memset(p + c->num, 0, 32);
  		hash_step(c, c->H, p);
  		add_blocks(32, c->S, p);
  	}
  
  	p = T;
  	HOST_l2c(c->Nl, p);
  	HOST_l2c(c->Nh, p);
  	memset(p, 0, 32 - 8);
  	hash_step(c, c->H, T);
  	hash_step(c, c->H, c->S);
  
  	memcpy(md, c->H, 32);
  
  	return 1;
  }
  
  unsigned char *
  GOSTR341194(const unsigned char *d, size_t n, unsigned char *md, int nid)
  {
  	GOSTR341194_CTX c;
  	static unsigned char m[GOSTR341194_LENGTH];
  
  	if (md == NULL)
  		md = m;
  	if (!GOSTR341194_Init(&c, nid))
  		return 0;
  	GOSTR341194_Update(&c, d, n);
  	GOSTR341194_Final(md, &c);
  	OPENSSL_cleanse(&c, sizeof(c));
  	return (md);
  }
  #endif
  