/**********************************************************************
  Copyright(c) 2011-2016 Intel Corporation All rights reserved.

  Redistribution and use in source and binary forms, with or without
  modification, are permitted provided that the following conditions 
  are met:
    * Redistributions of source code must retain the above copyright
      notice, this list of conditions and the following disclaimer.
    * 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.
    * Neither the name of Intel Corporation nor the names of its
      contributors may be used to endorse or promote products derived
      from this software without specific prior written permission.

  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  "AS IS" AND ANY EXPRESS 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 COPYRIGHT
  OWNER OR 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 "sha512_mb.h"

////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////
// Reference SHA512 Functions
////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////

#define H0 0x6a09e667f3bcc908
#define H1 0xbb67ae8584caa73b
#define H2 0x3c6ef372fe94f82b
#define H3 0xa54ff53a5f1d36f1
#define H4 0x510e527fade682d1
#define H5 0x9b05688c2b3e6c1f
#define H6 0x1f83d9abfb41bd6b
#define H7 0x5be0cd19137e2179

void sha512_single(const uint8_t * data, uint64_t digest[5]);

void sha512_ref(uint8_t * input_data, uint64_t * digest, uint32_t len)
{
	uint32_t i, j;
	uint8_t buf[2 * SHA512_BLOCK_SIZE];

	/* 128 bit lengths not needed as len is uint32_t, so use 64 bit length
	 * and pad the first 64 bits with zeros. */
	union {
		uint64_t uint;
		uint8_t uchar[8];
	} convert;
	uint8_t *p;

	digest[0] = H0;
	digest[1] = H1;
	digest[2] = H2;
	digest[3] = H3;
	digest[4] = H4;
	digest[5] = H5;
	digest[6] = H6;
	digest[7] = H7;

	i = len;
	/* Hash the complete blocks */
	while (i >= SHA512_BLOCK_SIZE) {
		sha512_single(input_data, digest);
		input_data += SHA512_BLOCK_SIZE;
		i -= SHA512_BLOCK_SIZE;
	}

	/* Copy remainder to a buffer to be padded */
	memcpy(buf, input_data, i);
	buf[i++] = 0x80;

	// Pad more than required here and overwrite with length
	for (j = i; j < (2 * SHA512_BLOCK_SIZE); j++)
		buf[j] = 0;

	if (i > SHA512_BLOCK_SIZE - SHA512_PADLENGTHFIELD_SIZE)
		i = 2 * SHA512_BLOCK_SIZE;
	else
		i = SHA512_BLOCK_SIZE;

	convert.uint = 8 * len;
	p = buf + i - 8;
	p[0] = convert.uchar[7];
	p[1] = convert.uchar[6];
	p[2] = convert.uchar[5];
	p[3] = convert.uchar[4];
	p[4] = convert.uchar[3];
	p[5] = convert.uchar[2];
	p[6] = convert.uchar[1];
	p[7] = convert.uchar[0];

	/* Hash the padded last block */
	sha512_single(buf, digest);
	if (i == 256)
		sha512_single(buf + 128, digest);
}

/* From the FIPS, these are the same as for SHA256, but operating on 64 bit words
 * instead of 32 bit. 
 */
#define ch(e,f,g) ((e & f) ^ (g & ~e))
#define maj(a,b,c) ((a & b) ^ (a & c) ^ (b & c))

/* Sigma functions have same form as SHA256 but 
 * 	- change the word size to 64bit
 * 	- change the amount to rotate 
 */
#define ror64(x, r) (((x)>>(r)) ^ ((x)<<(64-(r))))

/* Technically, s0 should be S0 as these are "capital sigma" functions, and likewise the case 
 * of the  S0 should be s0, but keep as-is to avoid confusion with the other reference functions.
 */
#define s0(a) (ror64(a,28) ^ ror64(a,34) ^ ror64(a,39))
#define s1(e) (ror64(e,14) ^ ror64(e,18) ^ ror64(e,41))

#define S0(w) (ror64(w,1) ^ ror64(w,8) ^ (w >> 7))
#define S1(w) (ror64(w,19) ^ ror64(w,61) ^ (w >> 6))

#define bswap(x)  (((x) & (0xffull << 0)) << 56) \
		| (((x) & (0xffull << 8)) << 40) \
		| (((x) & (0xffull <<16)) << 24) \
		| (((x) & (0xffull <<24)) << 8)  \
		| (((x) & (0xffull <<32)) >> 8)  \
		| (((x) & (0xffull <<40)) >> 24) \
		| (((x) & (0xffull <<48)) >> 40) \
		| (((x) & (0xffull <<56)) >> 56)

#define W(x) w[(x) & 15]

#define step(i,a,b,c,d,e,f,g,h,k) \
	if (i<16) W(i) = bswap(ww[i]); \
	else \
	W(i) = W(i-16) + S0(W(i-15)) + W(i-7) + S1(W(i-2)); \
	t2 = s0(a) + maj(a,b,c); \
	t1 = h + s1(e) + ch(e,f,g) + k + W(i); \
	d += t1; \
	h = t1 + t2;

void sha512_single(const uint8_t * data, uint64_t digest[5])
{
	/* Check these are all uint64_t */
	uint64_t a, b, c, d, e, f, g, h, t1, t2;
	uint64_t w[16];
	uint64_t *ww = (uint64_t *) data;

	a = digest[0];
	b = digest[1];
	c = digest[2];
	d = digest[3];
	e = digest[4];
	f = digest[5];
	g = digest[6];
	h = digest[7];

	step(0, a, b, c, d, e, f, g, h, 0x428a2f98d728ae22);
	step(1, h, a, b, c, d, e, f, g, 0x7137449123ef65cd);
	step(2, g, h, a, b, c, d, e, f, 0xb5c0fbcfec4d3b2f);
	step(3, f, g, h, a, b, c, d, e, 0xe9b5dba58189dbbc);
	step(4, e, f, g, h, a, b, c, d, 0x3956c25bf348b538);
	step(5, d, e, f, g, h, a, b, c, 0x59f111f1b605d019);
	step(6, c, d, e, f, g, h, a, b, 0x923f82a4af194f9b);
	step(7, b, c, d, e, f, g, h, a, 0xab1c5ed5da6d8118);
	step(8, a, b, c, d, e, f, g, h, 0xd807aa98a3030242);
	step(9, h, a, b, c, d, e, f, g, 0x12835b0145706fbe);
	step(10, g, h, a, b, c, d, e, f, 0x243185be4ee4b28c);
	step(11, f, g, h, a, b, c, d, e, 0x550c7dc3d5ffb4e2);
	step(12, e, f, g, h, a, b, c, d, 0x72be5d74f27b896f);
	step(13, d, e, f, g, h, a, b, c, 0x80deb1fe3b1696b1);
	step(14, c, d, e, f, g, h, a, b, 0x9bdc06a725c71235);
	step(15, b, c, d, e, f, g, h, a, 0xc19bf174cf692694);
	step(16, a, b, c, d, e, f, g, h, 0xe49b69c19ef14ad2);
	step(17, h, a, b, c, d, e, f, g, 0xefbe4786384f25e3);
	step(18, g, h, a, b, c, d, e, f, 0x0fc19dc68b8cd5b5);
	step(19, f, g, h, a, b, c, d, e, 0x240ca1cc77ac9c65);
	step(20, e, f, g, h, a, b, c, d, 0x2de92c6f592b0275);
	step(21, d, e, f, g, h, a, b, c, 0x4a7484aa6ea6e483);
	step(22, c, d, e, f, g, h, a, b, 0x5cb0a9dcbd41fbd4);
	step(23, b, c, d, e, f, g, h, a, 0x76f988da831153b5);
	step(24, a, b, c, d, e, f, g, h, 0x983e5152ee66dfab);
	step(25, h, a, b, c, d, e, f, g, 0xa831c66d2db43210);
	step(26, g, h, a, b, c, d, e, f, 0xb00327c898fb213f);
	step(27, f, g, h, a, b, c, d, e, 0xbf597fc7beef0ee4);
	step(28, e, f, g, h, a, b, c, d, 0xc6e00bf33da88fc2);
	step(29, d, e, f, g, h, a, b, c, 0xd5a79147930aa725);
	step(30, c, d, e, f, g, h, a, b, 0x06ca6351e003826f);
	step(31, b, c, d, e, f, g, h, a, 0x142929670a0e6e70);
	step(32, a, b, c, d, e, f, g, h, 0x27b70a8546d22ffc);
	step(33, h, a, b, c, d, e, f, g, 0x2e1b21385c26c926);
	step(34, g, h, a, b, c, d, e, f, 0x4d2c6dfc5ac42aed);
	step(35, f, g, h, a, b, c, d, e, 0x53380d139d95b3df);
	step(36, e, f, g, h, a, b, c, d, 0x650a73548baf63de);
	step(37, d, e, f, g, h, a, b, c, 0x766a0abb3c77b2a8);
	step(38, c, d, e, f, g, h, a, b, 0x81c2c92e47edaee6);
	step(39, b, c, d, e, f, g, h, a, 0x92722c851482353b);
	step(40, a, b, c, d, e, f, g, h, 0xa2bfe8a14cf10364);
	step(41, h, a, b, c, d, e, f, g, 0xa81a664bbc423001);
	step(42, g, h, a, b, c, d, e, f, 0xc24b8b70d0f89791);
	step(43, f, g, h, a, b, c, d, e, 0xc76c51a30654be30);
	step(44, e, f, g, h, a, b, c, d, 0xd192e819d6ef5218);
	step(45, d, e, f, g, h, a, b, c, 0xd69906245565a910);
	step(46, c, d, e, f, g, h, a, b, 0xf40e35855771202a);
	step(47, b, c, d, e, f, g, h, a, 0x106aa07032bbd1b8);
	step(48, a, b, c, d, e, f, g, h, 0x19a4c116b8d2d0c8);
	step(49, h, a, b, c, d, e, f, g, 0x1e376c085141ab53);
	step(50, g, h, a, b, c, d, e, f, 0x2748774cdf8eeb99);
	step(51, f, g, h, a, b, c, d, e, 0x34b0bcb5e19b48a8);
	step(52, e, f, g, h, a, b, c, d, 0x391c0cb3c5c95a63);
	step(53, d, e, f, g, h, a, b, c, 0x4ed8aa4ae3418acb);
	step(54, c, d, e, f, g, h, a, b, 0x5b9cca4f7763e373);
	step(55, b, c, d, e, f, g, h, a, 0x682e6ff3d6b2b8a3);
	step(56, a, b, c, d, e, f, g, h, 0x748f82ee5defb2fc);
	step(57, h, a, b, c, d, e, f, g, 0x78a5636f43172f60);
	step(58, g, h, a, b, c, d, e, f, 0x84c87814a1f0ab72);
	step(59, f, g, h, a, b, c, d, e, 0x8cc702081a6439ec);
	step(60, e, f, g, h, a, b, c, d, 0x90befffa23631e28);
	step(61, d, e, f, g, h, a, b, c, 0xa4506cebde82bde9);
	step(62, c, d, e, f, g, h, a, b, 0xbef9a3f7b2c67915);
	step(63, b, c, d, e, f, g, h, a, 0xc67178f2e372532b);	// step 63
	step(64, a, b, c, d, e, f, g, h, 0xca273eceea26619c);
	step(65, h, a, b, c, d, e, f, g, 0xd186b8c721c0c207);
	step(66, g, h, a, b, c, d, e, f, 0xeada7dd6cde0eb1e);
	step(67, f, g, h, a, b, c, d, e, 0xf57d4f7fee6ed178);
	step(68, e, f, g, h, a, b, c, d, 0x06f067aa72176fba);
	step(69, d, e, f, g, h, a, b, c, 0x0a637dc5a2c898a6);
	step(70, c, d, e, f, g, h, a, b, 0x113f9804bef90dae);
	step(71, b, c, d, e, f, g, h, a, 0x1b710b35131c471b);
	step(72, a, b, c, d, e, f, g, h, 0x28db77f523047d84);
	step(73, h, a, b, c, d, e, f, g, 0x32caab7b40c72493);
	step(74, g, h, a, b, c, d, e, f, 0x3c9ebe0a15c9bebc);
	step(75, f, g, h, a, b, c, d, e, 0x431d67c49c100d4c);
	step(76, e, f, g, h, a, b, c, d, 0x4cc5d4becb3e42b6);
	step(77, d, e, f, g, h, a, b, c, 0x597f299cfc657e2a);
	step(78, c, d, e, f, g, h, a, b, 0x5fcb6fab3ad6faec);
	step(79, b, c, d, e, f, g, h, a, 0x6c44198c4a475817);	// step 79

	digest[0] += a;
	digest[1] += b;
	digest[2] += c;
	digest[3] += d;
	digest[4] += e;
	digest[5] += f;
	digest[6] += g;
	digest[7] += h;
}
