block-internal.h 5.2 KB
Newer Older
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92
/* block-internal.h

   Internal implementations of nettle_blockZ-related functions.

   Copyright (C) 2011 Katholieke Universiteit Leuven
   Copyright (C) 2011, 2013, 2018 Niels Möller
   Copyright (C) 2018 Red Hat, Inc.
   Copyright (C) 2019 Dmitry Eremin-Solenikov

   This file is part of GNU Nettle.

   GNU Nettle is free software: you can redistribute it and/or
   modify it under the terms of either:

     * the GNU Lesser General Public License as published by the Free
       Software Foundation; either version 3 of the License, or (at your
       option) any later version.

   or

     * 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.

   or both in parallel, as here.

   GNU Nettle is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
   General Public License for more details.

   You should have received copies of the GNU General Public License and
   the GNU Lesser General Public License along with this program.  If
   not, see http://www.gnu.org/licenses/.
*/

#ifndef NETTLE_BLOCK_INTERNAL_H_INCLUDED
#define NETTLE_BLOCK_INTERNAL_H_INCLUDED

#include <assert.h>

#include "nettle-types.h"
#include "memxor.h"

static inline void
block16_xor (union nettle_block16 *r,
	     const union nettle_block16 *x)
{
  r->u64[0] ^= x->u64[0];
  r->u64[1] ^= x->u64[1];
}

static inline void
block16_xor3 (union nettle_block16 *r,
	      const union nettle_block16 *x,
	      const union nettle_block16 *y)
{
  r->u64[0] = x->u64[0] ^ y->u64[0];
  r->u64[1] = x->u64[1] ^ y->u64[1];
}

static inline void
block16_xor_bytes (union nettle_block16 *r,
		   const union nettle_block16 *x,
		   const uint8_t *bytes)
{
  memxor3 (r->b, x->b, bytes, 16);
}

static inline void
block8_xor (union nettle_block8 *r,
	    const union nettle_block8 *x)
{
  r->u64 ^= x->u64;
}

static inline void
block8_xor3 (union nettle_block8 *r,
	     const union nettle_block8 *x,
	     const union nettle_block8 *y)
{
  r->u64 = x->u64 ^ y->u64;
}

static inline void
block8_xor_bytes (union nettle_block8 *r,
		  const union nettle_block8 *x,
		  const uint8_t *bytes)
{
  memxor3 (r->b, x->b, bytes, 8);
}

93 94 95 96 97
/* Do a foreign-endianness shift of data */

#define LSHIFT_ALIEN_UINT64(x) \
	((((x) & UINT64_C(0x7f7f7f7f7f7f7f7f)) << 1) | \
	 (((x) & UINT64_C(0x8080808080808080)) >> 15))
98 99 100
#define RSHIFT_ALIEN_UINT64(x) \
	((((x) & UINT64_C(0xfefefefefefefefe)) >> 1) | \
	 (((x) & UINT64_C(0x0001010101010101)) << 15))
101 102 103 104 105

/* Two typical defining polynoms */

#define BLOCK16_POLY (UINT64_C(0x87))
#define BLOCK8_POLY (UINT64_C(0x1b))
106
#define GHASH_POLY (UINT64_C(0xE1))
107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139

/* Galois multiplications by 2:
 * functions differ in shifting right or left, big- or little- endianness
 * and by defining polynom.
 * r == x is allowed. */

#if WORDS_BIGENDIAN
static inline void
block16_mulx_be (union nettle_block16 *dst,
		 const union nettle_block16 *src)
{
  uint64_t carry = src->u64[0] >> 63;
  dst->u64[0] = (src->u64[0] << 1) | (src->u64[1] >> 63);
  dst->u64[1] = (src->u64[1] << 1) ^ (BLOCK16_POLY & -carry);
}

static inline void
block16_mulx_le (union nettle_block16 *dst,
		 const union nettle_block16 *src)
{
  uint64_t carry = (src->u64[1] & 0x80) >> 7;
  dst->u64[1] = LSHIFT_ALIEN_UINT64(src->u64[1]) | ((src->u64[0] & 0x80) << 49);
  dst->u64[0] = LSHIFT_ALIEN_UINT64(src->u64[0]) ^ ((BLOCK16_POLY << 56) & -carry);
}

static inline void
block8_mulx_be (union nettle_block8 *dst,
		const union nettle_block8 *src)
{
  uint64_t carry = src->u64 >> 63;

  dst->u64 = (src->u64 << 1) ^ (BLOCK8_POLY & -carry);
}
140 141 142 143 144 145 146 147 148 149 150 151

static inline void
block16_mulx_ghash (union nettle_block16 *r,
		    const union nettle_block16 *x)
{
  uint64_t mask;

  /* Shift uses big-endian representation. */
  mask = - (x->u64[1] & 1);
  r->u64[1] = (x->u64[1] >> 1) | ((x->u64[0] & 1) << 63);
  r->u64[0] = (x->u64[0] >> 1) ^ (mask & (GHASH_POLY << 56));
}
152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178
#else /* !WORDS_BIGENDIAN */
static inline void
block16_mulx_be (union nettle_block16 *dst,
		 const union nettle_block16 *src)
{
  uint64_t carry = (src->u64[0] & 0x80) >> 7;
  dst->u64[0] = LSHIFT_ALIEN_UINT64(src->u64[0]) | ((src->u64[1] & 0x80) << 49);
  dst->u64[1] = LSHIFT_ALIEN_UINT64(src->u64[1]) ^ ((BLOCK16_POLY << 56) & -carry);
}

static inline void
block16_mulx_le (union nettle_block16 *dst,
		 const union nettle_block16 *src)
{
  uint64_t carry = src->u64[1] >> 63;
  dst->u64[1] = (src->u64[1] << 1) | (src->u64[0] >> 63);
  dst->u64[0] = (src->u64[0] << 1) ^ (BLOCK16_POLY & -carry);
}

static inline void
block8_mulx_be (union nettle_block8 *dst,
		const union nettle_block8 *src)
{
  uint64_t carry = (src->u64 & 0x80) >> 7;

  dst->u64 = LSHIFT_ALIEN_UINT64(src->u64) ^ ((BLOCK8_POLY << 56) & -carry);
}
179 180 181 182 183 184 185 186 187 188 189 190 191

static inline void
block16_mulx_ghash (union nettle_block16 *r,
		    const union nettle_block16 *x)
{
  uint64_t mask;

  /* Shift uses big-endian representation. */
  mask = - ((x->u64[1] >> 56) & 1);
  r->u64[1] = RSHIFT_ALIEN_UINT64(x->u64[1]) | ((x->u64[0] >> 49) & 0x80);
  r->u64[0] = RSHIFT_ALIEN_UINT64(x->u64[0]) ^ (mask & GHASH_POLY);
}
#endif /* ! WORDS_BIGENDIAN */
192

193
#endif /* NETTLE_BLOCK_INTERNAL_H_INCLUDED */