kern/lib/crypto/2sha256.c - akaros - Git at Google

 /* SHA-256 and SHA-512 implementation based on code by Oliver Gay
  * <olivier.gay@a3.epfl.ch> under a BSD-style license. See below.
  */

 /*
  * FIPS 180-2 SHA-224/256/384/512 implementation
  * Last update: 02/02/2007
  * Issue date:  04/30/2005
  *
  * Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
  * All rights reserved.
  *
  * 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. Neither the name of the project 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 PROJECT 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 PROJECT 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 <crypto/2sysincludes.h>
 #include <crypto/2common.h>
 #include <crypto/2sha.h>

 #define SHFR(x, n)    (x >> n)
 #define ROTR(x, n)   ((x >> n) | (x << ((sizeof(x) << 3) - n)))
 #define ROTL(x, n)   ((x << n) | (x >> ((sizeof(x) << 3) - n)))
 #define CH(x, y, z)  ((x & y) ^ (~x & z))
 #define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))

 #define SHA256_F1(x) (ROTR(x,  2) ^ ROTR(x, 13) ^ ROTR(x, 22))
 #define SHA256_F2(x) (ROTR(x,  6) ^ ROTR(x, 11) ^ ROTR(x, 25))
 #define SHA256_F3(x) (ROTR(x,  7) ^ ROTR(x, 18) ^ SHFR(x,  3))
 #define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))

 #define UNPACK32(x, str)				\
 	{						\
 		*((str) + 3) = (uint8_t) ((x)      );	\
 		*((str) + 2) = (uint8_t) ((x) >>  8);	\
 		*((str) + 1) = (uint8_t) ((x) >> 16);	\
 		*((str) + 0) = (uint8_t) ((x) >> 24);	\
 	}

 #define PACK32(str, x)						\
 	{							\
 		*(x) =   ((uint32_t) *((str) + 3)      )	\
 			| ((uint32_t) *((str) + 2) <<  8)       \
 			| ((uint32_t) *((str) + 1) << 16)       \
 			| ((uint32_t) *((str) + 0) << 24);      \
 	}

 /* Macros used for loops unrolling */

 #define SHA256_SCR(i)						\
 	{							\
 		w[i] =  SHA256_F4(w[i -  2]) + w[i -  7]	\
 			+ SHA256_F3(w[i - 15]) + w[i - 16];	\
 	}

 #define SHA256_EXP(a, b, c, d, e, f, g, h, j)				\
 	{								\
 		t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) \
 			+ sha256_k[j] + w[j];				\
 		t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]);       \
 		wv[d] += t1;                                            \
 		wv[h] = t1 + t2;                                        \
 	}

 static const uint32_t sha256_h0[8] = {
 	0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
 	0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
 };

 static const uint32_t sha256_k[64] = {
 	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
 	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
 	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
 	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
 	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
 	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
 	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
 	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
 	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
 	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
 	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
 	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
 	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
 	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
 	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
 	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
 };

 /* SHA-256 implementation */
 void vb2_sha256_init(struct vb2_sha256_context *ctx)
 {
 #ifndef UNROLL_LOOPS
 	int i;
 	for (i = 0; i < 8; i++) {
 		ctx->h[i] = sha256_h0[i];
 	}
 #else
 	ctx->h[0] = sha256_h0[0]; ctx->h[1] = sha256_h0[1];
 	ctx->h[2] = sha256_h0[2]; ctx->h[3] = sha256_h0[3];
 	ctx->h[4] = sha256_h0[4]; ctx->h[5] = sha256_h0[5];
 	ctx->h[6] = sha256_h0[6]; ctx->h[7] = sha256_h0[7];
 #endif /* !UNROLL_LOOPS */

 	ctx->size = 0;
 	ctx->total_size = 0;
 }

 static void vb2_sha256_transform(struct vb2_sha256_context *ctx,
 				 const uint8_t *message,
 				 unsigned int block_nb)
 {
 	/* Note that these arrays use 72*4=288 bytes of stack */
 	uint32_t w[64];
 	uint32_t wv[8];
 	uint32_t t1, t2;
 	const unsigned char *sub_block;
 	int i;

 #ifndef UNROLL_LOOPS
 	int j;
 #endif

 	for (i = 0; i < (int) block_nb; i++) {
 		sub_block = message + (i << 6);

 #ifndef UNROLL_LOOPS
 		for (j = 0; j < 16; j++) {
 			PACK32(&sub_block[j << 2], &w[j]);
 		}

 		for (j = 16; j < 64; j++) {
 			SHA256_SCR(j);
 		}

 		for (j = 0; j < 8; j++) {
 			wv[j] = ctx->h[j];
 		}

 		for (j = 0; j < 64; j++) {
 			t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
 				+ sha256_k[j] + w[j];
 			t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
 			wv[7] = wv[6];
 			wv[6] = wv[5];
 			wv[5] = wv[4];
 			wv[4] = wv[3] + t1;
 			wv[3] = wv[2];
 			wv[2] = wv[1];
 			wv[1] = wv[0];
 			wv[0] = t1 + t2;
 		}

 		for (j = 0; j < 8; j++) {
 			ctx->h[j] += wv[j];
 		}
 #else
 		PACK32(&sub_block[ 0], &w[ 0]); PACK32(&sub_block[ 4], &w[ 1]);
 		PACK32(&sub_block[ 8], &w[ 2]); PACK32(&sub_block[12], &w[ 3]);
 		PACK32(&sub_block[16], &w[ 4]); PACK32(&sub_block[20], &w[ 5]);
 		PACK32(&sub_block[24], &w[ 6]); PACK32(&sub_block[28], &w[ 7]);
 		PACK32(&sub_block[32], &w[ 8]); PACK32(&sub_block[36], &w[ 9]);
 		PACK32(&sub_block[40], &w[10]); PACK32(&sub_block[44], &w[11]);
 		PACK32(&sub_block[48], &w[12]); PACK32(&sub_block[52], &w[13]);
 		PACK32(&sub_block[56], &w[14]); PACK32(&sub_block[60], &w[15]);

 		SHA256_SCR(16); SHA256_SCR(17); SHA256_SCR(18); SHA256_SCR(19);
 		SHA256_SCR(20); SHA256_SCR(21); SHA256_SCR(22); SHA256_SCR(23);
 		SHA256_SCR(24); SHA256_SCR(25); SHA256_SCR(26); SHA256_SCR(27);
 		SHA256_SCR(28); SHA256_SCR(29); SHA256_SCR(30); SHA256_SCR(31);
 		SHA256_SCR(32); SHA256_SCR(33); SHA256_SCR(34); SHA256_SCR(35);
 		SHA256_SCR(36); SHA256_SCR(37); SHA256_SCR(38); SHA256_SCR(39);
 		SHA256_SCR(40); SHA256_SCR(41); SHA256_SCR(42); SHA256_SCR(43);
 		SHA256_SCR(44); SHA256_SCR(45); SHA256_SCR(46); SHA256_SCR(47);
 		SHA256_SCR(48); SHA256_SCR(49); SHA256_SCR(50); SHA256_SCR(51);
 		SHA256_SCR(52); SHA256_SCR(53); SHA256_SCR(54); SHA256_SCR(55);
 		SHA256_SCR(56); SHA256_SCR(57); SHA256_SCR(58); SHA256_SCR(59);
 		SHA256_SCR(60); SHA256_SCR(61); SHA256_SCR(62); SHA256_SCR(63);

 		wv[0] = ctx->h[0]; wv[1] = ctx->h[1];
 		wv[2] = ctx->h[2]; wv[3] = ctx->h[3];
 		wv[4] = ctx->h[4]; wv[5] = ctx->h[5];
 		wv[6] = ctx->h[6]; wv[7] = ctx->h[7];

 		SHA256_EXP(0,1,2,3,4,5,6,7, 0); SHA256_EXP(7,0,1,2,3,4,5,6, 1);
 		SHA256_EXP(6,7,0,1,2,3,4,5, 2); SHA256_EXP(5,6,7,0,1,2,3,4, 3);
 		SHA256_EXP(4,5,6,7,0,1,2,3, 4); SHA256_EXP(3,4,5,6,7,0,1,2, 5);
 		SHA256_EXP(2,3,4,5,6,7,0,1, 6); SHA256_EXP(1,2,3,4,5,6,7,0, 7);
 		SHA256_EXP(0,1,2,3,4,5,6,7, 8); SHA256_EXP(7,0,1,2,3,4,5,6, 9);
 		SHA256_EXP(6,7,0,1,2,3,4,5,10); SHA256_EXP(5,6,7,0,1,2,3,4,11);
 		SHA256_EXP(4,5,6,7,0,1,2,3,12); SHA256_EXP(3,4,5,6,7,0,1,2,13);
 		SHA256_EXP(2,3,4,5,6,7,0,1,14); SHA256_EXP(1,2,3,4,5,6,7,0,15);
 		SHA256_EXP(0,1,2,3,4,5,6,7,16); SHA256_EXP(7,0,1,2,3,4,5,6,17);
 		SHA256_EXP(6,7,0,1,2,3,4,5,18); SHA256_EXP(5,6,7,0,1,2,3,4,19);
 		SHA256_EXP(4,5,6,7,0,1,2,3,20); SHA256_EXP(3,4,5,6,7,0,1,2,21);
 		SHA256_EXP(2,3,4,5,6,7,0,1,22); SHA256_EXP(1,2,3,4,5,6,7,0,23);
 		SHA256_EXP(0,1,2,3,4,5,6,7,24); SHA256_EXP(7,0,1,2,3,4,5,6,25);
 		SHA256_EXP(6,7,0,1,2,3,4,5,26); SHA256_EXP(5,6,7,0,1,2,3,4,27);
 		SHA256_EXP(4,5,6,7,0,1,2,3,28); SHA256_EXP(3,4,5,6,7,0,1,2,29);
 		SHA256_EXP(2,3,4,5,6,7,0,1,30); SHA256_EXP(1,2,3,4,5,6,7,0,31);
 		SHA256_EXP(0,1,2,3,4,5,6,7,32); SHA256_EXP(7,0,1,2,3,4,5,6,33);
 		SHA256_EXP(6,7,0,1,2,3,4,5,34); SHA256_EXP(5,6,7,0,1,2,3,4,35);
 		SHA256_EXP(4,5,6,7,0,1,2,3,36); SHA256_EXP(3,4,5,6,7,0,1,2,37);
 		SHA256_EXP(2,3,4,5,6,7,0,1,38); SHA256_EXP(1,2,3,4,5,6,7,0,39);
 		SHA256_EXP(0,1,2,3,4,5,6,7,40); SHA256_EXP(7,0,1,2,3,4,5,6,41);
 		SHA256_EXP(6,7,0,1,2,3,4,5,42); SHA256_EXP(5,6,7,0,1,2,3,4,43);
 		SHA256_EXP(4,5,6,7,0,1,2,3,44); SHA256_EXP(3,4,5,6,7,0,1,2,45);
 		SHA256_EXP(2,3,4,5,6,7,0,1,46); SHA256_EXP(1,2,3,4,5,6,7,0,47);
 		SHA256_EXP(0,1,2,3,4,5,6,7,48); SHA256_EXP(7,0,1,2,3,4,5,6,49);
 		SHA256_EXP(6,7,0,1,2,3,4,5,50); SHA256_EXP(5,6,7,0,1,2,3,4,51);
 		SHA256_EXP(4,5,6,7,0,1,2,3,52); SHA256_EXP(3,4,5,6,7,0,1,2,53);
 		SHA256_EXP(2,3,4,5,6,7,0,1,54); SHA256_EXP(1,2,3,4,5,6,7,0,55);
 		SHA256_EXP(0,1,2,3,4,5,6,7,56); SHA256_EXP(7,0,1,2,3,4,5,6,57);
 		SHA256_EXP(6,7,0,1,2,3,4,5,58); SHA256_EXP(5,6,7,0,1,2,3,4,59);
 		SHA256_EXP(4,5,6,7,0,1,2,3,60); SHA256_EXP(3,4,5,6,7,0,1,2,61);
 		SHA256_EXP(2,3,4,5,6,7,0,1,62); SHA256_EXP(1,2,3,4,5,6,7,0,63);

 		ctx->h[0] += wv[0]; ctx->h[1] += wv[1];
 		ctx->h[2] += wv[2]; ctx->h[3] += wv[3];
 		ctx->h[4] += wv[4]; ctx->h[5] += wv[5];
 		ctx->h[6] += wv[6]; ctx->h[7] += wv[7];
 #endif /* !UNROLL_LOOPS */
 	}
 }

 void vb2_sha256_update(struct vb2_sha256_context *ctx,
 		       const uint8_t *data,
 		       uint32_t size)
 {
 	unsigned int block_nb;
 	unsigned int new_size, rem_size, tmp_size;
 	const uint8_t *shifted_data;

 	tmp_size = VB2_SHA256_BLOCK_SIZE - ctx->size;
 	rem_size = size < tmp_size ? size : tmp_size;

 	memcpy(&ctx->block[ctx->size], data, rem_size);

 	if (ctx->size + size < VB2_SHA256_BLOCK_SIZE) {
 		ctx->size += size;
 		return;
 	}

 	new_size = size - rem_size;
 	block_nb = new_size / VB2_SHA256_BLOCK_SIZE;

 	shifted_data = data + rem_size;

 	vb2_sha256_transform(ctx, ctx->block, 1);
 	vb2_sha256_transform(ctx, shifted_data, block_nb);

 	rem_size = new_size % VB2_SHA256_BLOCK_SIZE;

 	memcpy(ctx->block, &shifted_data[block_nb << 6],
 	       rem_size);

 	ctx->size = rem_size;
 	ctx->total_size += (block_nb + 1) << 6;
 }

 void vb2_sha256_finalize(struct vb2_sha256_context *ctx, uint8_t *digest)
 {
 	unsigned int block_nb;
 	unsigned int pm_size;
 	unsigned int size_b;
 #ifndef UNROLL_LOOPS
 	int i;
 #endif

 	block_nb = (1 + ((VB2_SHA256_BLOCK_SIZE - 9)
 			 < (ctx->size % VB2_SHA256_BLOCK_SIZE)));

 	size_b = (ctx->total_size + ctx->size) << 3;
 	pm_size = block_nb << 6;

 	memset(ctx->block + ctx->size, 0, pm_size - ctx->size);
 	ctx->block[ctx->size] = 0x80;
 	UNPACK32(size_b, ctx->block + pm_size - 4);

 	vb2_sha256_transform(ctx, ctx->block, block_nb);

 #ifndef UNROLL_LOOPS
 	for (i = 0 ; i < 8; i++) {
 		UNPACK32(ctx->h[i], &digest[i << 2]);
 	}
 #else
 	UNPACK32(ctx->h[0], &digest[ 0]);
 	UNPACK32(ctx->h[1], &digest[ 4]);
 	UNPACK32(ctx->h[2], &digest[ 8]);
 	UNPACK32(ctx->h[3], &digest[12]);
 	UNPACK32(ctx->h[4], &digest[16]);
 	UNPACK32(ctx->h[5], &digest[20]);
 	UNPACK32(ctx->h[6], &digest[24]);
 	UNPACK32(ctx->h[7], &digest[28]);
 #endif /* !UNROLL_LOOPS */
 }

 void vb2_sha256_extend(const uint8_t *from, const uint8_t *by, uint8_t *to)
 {
 	struct vb2_sha256_context dc;
 	int i;

 	for (i = 0; i < 8; i++) {
 		 PACK32(from, &dc.h[i]);
 		 from += 4;
 	}

 	vb2_sha256_transform(&dc, by, 1);

 	for (i = 0; i < 8; i++) {
 		 UNPACK32(dc.h[i], to);
 		 to += 4;
 	}
 }
	/* SHA-256 and SHA-512 implementation based on code by Oliver Gay
	* <olivier.gay@a3.epfl.ch> under a BSD-style license. See below.
	*/

	/*
	* FIPS 180-2 SHA-224/256/384/512 implementation
	* Last update: 02/02/2007
	* Issue date: 04/30/2005
	*
	* Copyright (C) 2005, 2007 Olivier Gay <olivier.gay@a3.epfl.ch>
	* All rights reserved.
	*
	* 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. Neither the name of the project 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 PROJECT 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 PROJECT 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 <crypto/2sysincludes.h>
	#include <crypto/2common.h>
	#include <crypto/2sha.h>

	#define SHFR(x, n) (x >> n)
	#define ROTR(x, n) ((x >> n) \| (x << ((sizeof(x) << 3) - n)))
	#define ROTL(x, n) ((x << n) \| (x >> ((sizeof(x) << 3) - n)))
	#define CH(x, y, z) ((x & y) ^ (~x & z))
	#define MAJ(x, y, z) ((x & y) ^ (x & z) ^ (y & z))

	#define SHA256_F1(x) (ROTR(x, 2) ^ ROTR(x, 13) ^ ROTR(x, 22))
	#define SHA256_F2(x) (ROTR(x, 6) ^ ROTR(x, 11) ^ ROTR(x, 25))
	#define SHA256_F3(x) (ROTR(x, 7) ^ ROTR(x, 18) ^ SHFR(x, 3))
	#define SHA256_F4(x) (ROTR(x, 17) ^ ROTR(x, 19) ^ SHFR(x, 10))

	#define UNPACK32(x, str) \
	{ \
	*((str) + 3) = (uint8_t) ((x) ); \
	*((str) + 2) = (uint8_t) ((x) >> 8); \
	*((str) + 1) = (uint8_t) ((x) >> 16); \
	*((str) + 0) = (uint8_t) ((x) >> 24); \
	}

	#define PACK32(str, x) \
	{ \
	(x) = ((uint32_t) ((str) + 3) ) \
	\| ((uint32_t) *((str) + 2) << 8) \
	\| ((uint32_t) *((str) + 1) << 16) \
	\| ((uint32_t) *((str) + 0) << 24); \
	}

	/* Macros used for loops unrolling */

	#define SHA256_SCR(i) \
	{ \
	w[i] = SHA256_F4(w[i - 2]) + w[i - 7] \
	+ SHA256_F3(w[i - 15]) + w[i - 16]; \
	}

	#define SHA256_EXP(a, b, c, d, e, f, g, h, j) \
	{ \
	t1 = wv[h] + SHA256_F2(wv[e]) + CH(wv[e], wv[f], wv[g]) \
	+ sha256_k[j] + w[j]; \
	t2 = SHA256_F1(wv[a]) + MAJ(wv[a], wv[b], wv[c]); \
	wv[d] += t1; \
	wv[h] = t1 + t2; \
	}

	static const uint32_t sha256_h0[8] = {
	0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
	0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
	};

	static const uint32_t sha256_k[64] = {
	0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
	0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
	0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
	0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
	0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
	0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
	0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
	0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
	0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
	0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
	0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
	0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
	0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
	0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
	0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
	0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
	};

	/* SHA-256 implementation */
	void vb2_sha256_init(struct vb2_sha256_context *ctx)
	{
	#ifndef UNROLL_LOOPS
	int i;
	for (i = 0; i < 8; i++) {
	ctx->h[i] = sha256_h0[i];
	}
	#else
	ctx->h[0] = sha256_h0[0]; ctx->h[1] = sha256_h0[1];
	ctx->h[2] = sha256_h0[2]; ctx->h[3] = sha256_h0[3];
	ctx->h[4] = sha256_h0[4]; ctx->h[5] = sha256_h0[5];
	ctx->h[6] = sha256_h0[6]; ctx->h[7] = sha256_h0[7];
	#endif /* !UNROLL_LOOPS */

	ctx->size = 0;
	ctx->total_size = 0;
	}

	static void vb2_sha256_transform(struct vb2_sha256_context *ctx,
	const uint8_t *message,
	unsigned int block_nb)
	{
	/* Note that these arrays use 724=288 bytes of stack /
	uint32_t w[64];
	uint32_t wv[8];
	uint32_t t1, t2;
	const unsigned char *sub_block;
	int i;

	#ifndef UNROLL_LOOPS
	int j;
	#endif

	for (i = 0; i < (int) block_nb; i++) {
	sub_block = message + (i << 6);

	#ifndef UNROLL_LOOPS
	for (j = 0; j < 16; j++) {
	PACK32(&sub_block[j << 2], &w[j]);
	}

	for (j = 16; j < 64; j++) {
	SHA256_SCR(j);
	}

	for (j = 0; j < 8; j++) {
	wv[j] = ctx->h[j];
	}

	for (j = 0; j < 64; j++) {
	t1 = wv[7] + SHA256_F2(wv[4]) + CH(wv[4], wv[5], wv[6])
	+ sha256_k[j] + w[j];
	t2 = SHA256_F1(wv[0]) + MAJ(wv[0], wv[1], wv[2]);
	wv[7] = wv[6];
	wv[6] = wv[5];
	wv[5] = wv[4];
	wv[4] = wv[3] + t1;
	wv[3] = wv[2];
	wv[2] = wv[1];
	wv[1] = wv[0];
	wv[0] = t1 + t2;
	}

	for (j = 0; j < 8; j++) {
	ctx->h[j] += wv[j];
	}
	#else
	PACK32(&sub_block[ 0], &w[ 0]); PACK32(&sub_block[ 4], &w[ 1]);
	PACK32(&sub_block[ 8], &w[ 2]); PACK32(&sub_block[12], &w[ 3]);
	PACK32(&sub_block[16], &w[ 4]); PACK32(&sub_block[20], &w[ 5]);
	PACK32(&sub_block[24], &w[ 6]); PACK32(&sub_block[28], &w[ 7]);
	PACK32(&sub_block[32], &w[ 8]); PACK32(&sub_block[36], &w[ 9]);
	PACK32(&sub_block[40], &w[10]); PACK32(&sub_block[44], &w[11]);
	PACK32(&sub_block[48], &w[12]); PACK32(&sub_block[52], &w[13]);
	PACK32(&sub_block[56], &w[14]); PACK32(&sub_block[60], &w[15]);

	SHA256_SCR(16); SHA256_SCR(17); SHA256_SCR(18); SHA256_SCR(19);
	SHA256_SCR(20); SHA256_SCR(21); SHA256_SCR(22); SHA256_SCR(23);
	SHA256_SCR(24); SHA256_SCR(25); SHA256_SCR(26); SHA256_SCR(27);
	SHA256_SCR(28); SHA256_SCR(29); SHA256_SCR(30); SHA256_SCR(31);
	SHA256_SCR(32); SHA256_SCR(33); SHA256_SCR(34); SHA256_SCR(35);
	SHA256_SCR(36); SHA256_SCR(37); SHA256_SCR(38); SHA256_SCR(39);
	SHA256_SCR(40); SHA256_SCR(41); SHA256_SCR(42); SHA256_SCR(43);
	SHA256_SCR(44); SHA256_SCR(45); SHA256_SCR(46); SHA256_SCR(47);
	SHA256_SCR(48); SHA256_SCR(49); SHA256_SCR(50); SHA256_SCR(51);
	SHA256_SCR(52); SHA256_SCR(53); SHA256_SCR(54); SHA256_SCR(55);
	SHA256_SCR(56); SHA256_SCR(57); SHA256_SCR(58); SHA256_SCR(59);
	SHA256_SCR(60); SHA256_SCR(61); SHA256_SCR(62); SHA256_SCR(63);

	wv[0] = ctx->h[0]; wv[1] = ctx->h[1];
	wv[2] = ctx->h[2]; wv[3] = ctx->h[3];
	wv[4] = ctx->h[4]; wv[5] = ctx->h[5];
	wv[6] = ctx->h[6]; wv[7] = ctx->h[7];

	SHA256_EXP(0,1,2,3,4,5,6,7, 0); SHA256_EXP(7,0,1,2,3,4,5,6, 1);
	SHA256_EXP(6,7,0,1,2,3,4,5, 2); SHA256_EXP(5,6,7,0,1,2,3,4, 3);
	SHA256_EXP(4,5,6,7,0,1,2,3, 4); SHA256_EXP(3,4,5,6,7,0,1,2, 5);
	SHA256_EXP(2,3,4,5,6,7,0,1, 6); SHA256_EXP(1,2,3,4,5,6,7,0, 7);
	SHA256_EXP(0,1,2,3,4,5,6,7, 8); SHA256_EXP(7,0,1,2,3,4,5,6, 9);
	SHA256_EXP(6,7,0,1,2,3,4,5,10); SHA256_EXP(5,6,7,0,1,2,3,4,11);
	SHA256_EXP(4,5,6,7,0,1,2,3,12); SHA256_EXP(3,4,5,6,7,0,1,2,13);
	SHA256_EXP(2,3,4,5,6,7,0,1,14); SHA256_EXP(1,2,3,4,5,6,7,0,15);
	SHA256_EXP(0,1,2,3,4,5,6,7,16); SHA256_EXP(7,0,1,2,3,4,5,6,17);
	SHA256_EXP(6,7,0,1,2,3,4,5,18); SHA256_EXP(5,6,7,0,1,2,3,4,19);
	SHA256_EXP(4,5,6,7,0,1,2,3,20); SHA256_EXP(3,4,5,6,7,0,1,2,21);
	SHA256_EXP(2,3,4,5,6,7,0,1,22); SHA256_EXP(1,2,3,4,5,6,7,0,23);
	SHA256_EXP(0,1,2,3,4,5,6,7,24); SHA256_EXP(7,0,1,2,3,4,5,6,25);
	SHA256_EXP(6,7,0,1,2,3,4,5,26); SHA256_EXP(5,6,7,0,1,2,3,4,27);
	SHA256_EXP(4,5,6,7,0,1,2,3,28); SHA256_EXP(3,4,5,6,7,0,1,2,29);
	SHA256_EXP(2,3,4,5,6,7,0,1,30); SHA256_EXP(1,2,3,4,5,6,7,0,31);
	SHA256_EXP(0,1,2,3,4,5,6,7,32); SHA256_EXP(7,0,1,2,3,4,5,6,33);
	SHA256_EXP(6,7,0,1,2,3,4,5,34); SHA256_EXP(5,6,7,0,1,2,3,4,35);
	SHA256_EXP(4,5,6,7,0,1,2,3,36); SHA256_EXP(3,4,5,6,7,0,1,2,37);
	SHA256_EXP(2,3,4,5,6,7,0,1,38); SHA256_EXP(1,2,3,4,5,6,7,0,39);
	SHA256_EXP(0,1,2,3,4,5,6,7,40); SHA256_EXP(7,0,1,2,3,4,5,6,41);
	SHA256_EXP(6,7,0,1,2,3,4,5,42); SHA256_EXP(5,6,7,0,1,2,3,4,43);
	SHA256_EXP(4,5,6,7,0,1,2,3,44); SHA256_EXP(3,4,5,6,7,0,1,2,45);
	SHA256_EXP(2,3,4,5,6,7,0,1,46); SHA256_EXP(1,2,3,4,5,6,7,0,47);
	SHA256_EXP(0,1,2,3,4,5,6,7,48); SHA256_EXP(7,0,1,2,3,4,5,6,49);
	SHA256_EXP(6,7,0,1,2,3,4,5,50); SHA256_EXP(5,6,7,0,1,2,3,4,51);
	SHA256_EXP(4,5,6,7,0,1,2,3,52); SHA256_EXP(3,4,5,6,7,0,1,2,53);
	SHA256_EXP(2,3,4,5,6,7,0,1,54); SHA256_EXP(1,2,3,4,5,6,7,0,55);
	SHA256_EXP(0,1,2,3,4,5,6,7,56); SHA256_EXP(7,0,1,2,3,4,5,6,57);
	SHA256_EXP(6,7,0,1,2,3,4,5,58); SHA256_EXP(5,6,7,0,1,2,3,4,59);
	SHA256_EXP(4,5,6,7,0,1,2,3,60); SHA256_EXP(3,4,5,6,7,0,1,2,61);
	SHA256_EXP(2,3,4,5,6,7,0,1,62); SHA256_EXP(1,2,3,4,5,6,7,0,63);

	ctx->h[0] += wv[0]; ctx->h[1] += wv[1];
	ctx->h[2] += wv[2]; ctx->h[3] += wv[3];
	ctx->h[4] += wv[4]; ctx->h[5] += wv[5];
	ctx->h[6] += wv[6]; ctx->h[7] += wv[7];
	#endif /* !UNROLL_LOOPS */
	}
	}

	void vb2_sha256_update(struct vb2_sha256_context *ctx,
	const uint8_t *data,
	uint32_t size)
	{
	unsigned int block_nb;
	unsigned int new_size, rem_size, tmp_size;
	const uint8_t *shifted_data;

	tmp_size = VB2_SHA256_BLOCK_SIZE - ctx->size;
	rem_size = size < tmp_size ? size : tmp_size;

	memcpy(&ctx->block[ctx->size], data, rem_size);

	if (ctx->size + size < VB2_SHA256_BLOCK_SIZE) {
	ctx->size += size;
	return;
	}

	new_size = size - rem_size;
	block_nb = new_size / VB2_SHA256_BLOCK_SIZE;

	shifted_data = data + rem_size;

	vb2_sha256_transform(ctx, ctx->block, 1);
	vb2_sha256_transform(ctx, shifted_data, block_nb);

	rem_size = new_size % VB2_SHA256_BLOCK_SIZE;

	memcpy(ctx->block, &shifted_data[block_nb << 6],
	rem_size);

	ctx->size = rem_size;
	ctx->total_size += (block_nb + 1) << 6;
	}

	void vb2_sha256_finalize(struct vb2_sha256_context ctx, uint8_t digest)
	{
	unsigned int block_nb;
	unsigned int pm_size;
	unsigned int size_b;
	#ifndef UNROLL_LOOPS
	int i;
	#endif

	block_nb = (1 + ((VB2_SHA256_BLOCK_SIZE - 9)
	< (ctx->size % VB2_SHA256_BLOCK_SIZE)));

	size_b = (ctx->total_size + ctx->size) << 3;
	pm_size = block_nb << 6;

	memset(ctx->block + ctx->size, 0, pm_size - ctx->size);
	ctx->block[ctx->size] = 0x80;
	UNPACK32(size_b, ctx->block + pm_size - 4);

	vb2_sha256_transform(ctx, ctx->block, block_nb);

	#ifndef UNROLL_LOOPS
	for (i = 0 ; i < 8; i++) {
	UNPACK32(ctx->h[i], &digest[i << 2]);
	}
	#else
	UNPACK32(ctx->h[0], &digest[ 0]);
	UNPACK32(ctx->h[1], &digest[ 4]);
	UNPACK32(ctx->h[2], &digest[ 8]);
	UNPACK32(ctx->h[3], &digest[12]);
	UNPACK32(ctx->h[4], &digest[16]);
	UNPACK32(ctx->h[5], &digest[20]);
	UNPACK32(ctx->h[6], &digest[24]);
	UNPACK32(ctx->h[7], &digest[28]);
	#endif /* !UNROLL_LOOPS */
	}

	void vb2_sha256_extend(const uint8_t from, const uint8_t by, uint8_t *to)
	{
	struct vb2_sha256_context dc;
	int i;

	for (i = 0; i < 8; i++) {
	PACK32(from, &dc.h[i]);
	from += 4;
	}

	vb2_sha256_transform(&dc, by, 1);

	for (i = 0; i < 8; i++) {
	UNPACK32(dc.h[i], to);
	to += 4;
	}
	}