src/lib/crypto/crypto_scrypt-sse.c - chromiumos/third_party/libscrypt - Git at Google

 /*-
  * Copyright 2009 Colin Percival
  * 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.
  *
  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
  *
  * This file was originally written by Colin Percival as part of the Tarsnap
  * online backup system.
  */
 #include "scrypt_platform.h"

 #include <sys/types.h>
 #include <sys/mman.h>

 #include <emmintrin.h>
 #include <errno.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>

 #include "sha256.h"
 #include "sysendian.h"

 #include "crypto_scrypt.h"

 static void blkcpy(void *, void *, size_t);
 static void blkxor(void *, void *, size_t);
 static void salsa20_8(__m128i *);
 static void blockmix_salsa8(__m128i *, __m128i *, __m128i *, size_t);
 static uint64_t integerify(void *, size_t);
 static void smix(uint8_t *, size_t, uint64_t, void *, void *);

 static void
 blkcpy(void * dest, void * src, size_t len)
 {
 	__m128i * D = dest;
 	__m128i * S = src;
 	size_t L = len / 16;
 	size_t i;

 	for (i = 0; i < L; i++)
 		D[i] = S[i];
 }

 static void
 blkxor(void * dest, void * src, size_t len)
 {
 	__m128i * D = dest;
 	__m128i * S = src;
 	size_t L = len / 16;
 	size_t i;

 	for (i = 0; i < L; i++)
 		D[i] = _mm_xor_si128(D[i], S[i]);
 }

 /**
  * salsa20_8(B):
  * Apply the salsa20/8 core to the provided block.
  */
 static void
 salsa20_8(__m128i B[4])
 {
 	__m128i X0, X1, X2, X3;
 	__m128i T;
 	size_t i;

 	X0 = B[0];
 	X1 = B[1];
 	X2 = B[2];
 	X3 = B[3];

 	for (i = 0; i < 8; i += 2) {
 		/* Operate on "columns". */
 		T = _mm_add_epi32(X0, X3);
 		X1 = _mm_xor_si128(X1, _mm_slli_epi32(T, 7));
 		X1 = _mm_xor_si128(X1, _mm_srli_epi32(T, 25));
 		T = _mm_add_epi32(X1, X0);
 		X2 = _mm_xor_si128(X2, _mm_slli_epi32(T, 9));
 		X2 = _mm_xor_si128(X2, _mm_srli_epi32(T, 23));
 		T = _mm_add_epi32(X2, X1);
 		X3 = _mm_xor_si128(X3, _mm_slli_epi32(T, 13));
 		X3 = _mm_xor_si128(X3, _mm_srli_epi32(T, 19));
 		T = _mm_add_epi32(X3, X2);
 		X0 = _mm_xor_si128(X0, _mm_slli_epi32(T, 18));
 		X0 = _mm_xor_si128(X0, _mm_srli_epi32(T, 14));

 		/* Rearrange data. */
 		X1 = _mm_shuffle_epi32(X1, 0x93);
 		X2 = _mm_shuffle_epi32(X2, 0x4E);
 		X3 = _mm_shuffle_epi32(X3, 0x39);

 		/* Operate on "rows". */
 		T = _mm_add_epi32(X0, X1);
 		X3 = _mm_xor_si128(X3, _mm_slli_epi32(T, 7));
 		X3 = _mm_xor_si128(X3, _mm_srli_epi32(T, 25));
 		T = _mm_add_epi32(X3, X0);
 		X2 = _mm_xor_si128(X2, _mm_slli_epi32(T, 9));
 		X2 = _mm_xor_si128(X2, _mm_srli_epi32(T, 23));
 		T = _mm_add_epi32(X2, X3);
 		X1 = _mm_xor_si128(X1, _mm_slli_epi32(T, 13));
 		X1 = _mm_xor_si128(X1, _mm_srli_epi32(T, 19));
 		T = _mm_add_epi32(X1, X2);
 		X0 = _mm_xor_si128(X0, _mm_slli_epi32(T, 18));
 		X0 = _mm_xor_si128(X0, _mm_srli_epi32(T, 14));

 		/* Rearrange data. */
 		X1 = _mm_shuffle_epi32(X1, 0x39);
 		X2 = _mm_shuffle_epi32(X2, 0x4E);
 		X3 = _mm_shuffle_epi32(X3, 0x93);
 	}

 	B[0] = _mm_add_epi32(B[0], X0);
 	B[1] = _mm_add_epi32(B[1], X1);
 	B[2] = _mm_add_epi32(B[2], X2);
 	B[3] = _mm_add_epi32(B[3], X3);
 }

 /**
  * blockmix_salsa8(Bin, Bout, X, r):
  * Compute Bout = BlockMix_{salsa20/8, r}(Bin).  The input Bin must be 128r
  * bytes in length; the output Bout must also be the same size.  The
  * temporary space X must be 64 bytes.
  */
 static void
 blockmix_salsa8(__m128i * Bin, __m128i * Bout, __m128i * X, size_t r)
 {
 	size_t i;

 	/* 1: X <-- B_{2r - 1} */
 	blkcpy(X, &Bin[8 * r - 4], 64);

 	/* 2: for i = 0 to 2r - 1 do */
 	for (i = 0; i < r; i++) {
 		/* 3: X <-- H(X \xor B_i) */
 		blkxor(X, &Bin[i * 8], 64);
 		salsa20_8(X);

 		/* 4: Y_i <-- X */
 		/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
 		blkcpy(&Bout[i * 4], X, 64);

 		/* 3: X <-- H(X \xor B_i) */
 		blkxor(X, &Bin[i * 8 + 4], 64);
 		salsa20_8(X);

 		/* 4: Y_i <-- X */
 		/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
 		blkcpy(&Bout[(r + i) * 4], X, 64);
 	}
 }

 /**
  * integerify(B, r):
  * Return the result of parsing B_{2r-1} as a little-endian integer.
  */
 static uint64_t
 integerify(void * B, size_t r)
 {
 	uint32_t * X = (void *)((uintptr_t)(B) + (2 * r - 1) * 64);

 	return (((uint64_t)(X[13]) << 32) + X[0]);
 }

 /**
  * smix(B, r, N, V, XY):
  * Compute B = SMix_r(B, N).  The input B must be 128r bytes in length;
  * the temporary storage V must be 128rN bytes in length; the temporary
  * storage XY must be 256r + 64 bytes in length.  The value N must be a
  * power of 2 greater than 1.  The arrays B, V, and XY must be aligned to a
  * multiple of 64 bytes.
  */
 static void
 smix(uint8_t * B, size_t r, uint64_t N, void * V, void * XY)
 {
 	__m128i * X = XY;
 	__m128i * Y = (void *)((uintptr_t)(XY) + 128 * r);
 	__m128i * Z = (void *)((uintptr_t)(XY) + 256 * r);
 	uint32_t * X32 = (void *)X;
 	uint64_t i, j;
 	size_t k;

 	/* 1: X <-- B */
 	for (k = 0; k < 2 * r; k++) {
 		for (i = 0; i < 16; i++) {
 			X32[k * 16 + i] =
 			    le32dec(&B[(k * 16 + (i * 5 % 16)) * 4]);
 		}
 	}

 	/* 2: for i = 0 to N - 1 do */
 	for (i = 0; i < N; i += 2) {
 		/* 3: V_i <-- X */
 		blkcpy((void *)((uintptr_t)(V) + i * 128 * r), X, 128 * r);

 		/* 4: X <-- H(X) */
 		blockmix_salsa8(X, Y, Z, r);

 		/* 3: V_i <-- X */
 		blkcpy((void *)((uintptr_t)(V) + (i + 1) * 128 * r),
 		    Y, 128 * r);

 		/* 4: X <-- H(X) */
 		blockmix_salsa8(Y, X, Z, r);
 	}

 	/* 6: for i = 0 to N - 1 do */
 	for (i = 0; i < N; i += 2) {
 		/* 7: j <-- Integerify(X) mod N */
 		j = integerify(X, r) & (N - 1);

 		/* 8: X <-- H(X \xor V_j) */
 		blkxor(X, (void *)((uintptr_t)(V) + j * 128 * r), 128 * r);
 		blockmix_salsa8(X, Y, Z, r);

 		/* 7: j <-- Integerify(X) mod N */
 		j = integerify(Y, r) & (N - 1);

 		/* 8: X <-- H(X \xor V_j) */
 		blkxor(Y, (void *)((uintptr_t)(V) + j * 128 * r), 128 * r);
 		blockmix_salsa8(Y, X, Z, r);
 	}

 	/* 10: B' <-- X */
 	for (k = 0; k < 2 * r; k++) {
 		for (i = 0; i < 16; i++) {
 			le32enc(&B[(k * 16 + (i * 5 % 16)) * 4],
 			    X32[k * 16 + i]);
 		}
 	}
 }

 /**
  * crypto_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
  * Compute scrypt(passwd[0 .. passwdlen - 1], salt[0 .. saltlen - 1], N, r,
  * p, buflen) and write the result into buf.  The parameters r, p, and buflen
  * must satisfy r * p < 2^30 and buflen <= (2^32 - 1) * 32.  The parameter N
  * must be a power of 2 greater than 1.
  *
  * Return 0 on success; or -1 on error.
  */
 int
 crypto_scrypt(const uint8_t * passwd, size_t passwdlen,
     const uint8_t * salt, size_t saltlen, uint64_t N, uint32_t r, uint32_t p,
     uint8_t * buf, size_t buflen)
 {
 	void * B0, * V0, * XY0;
 	uint8_t * B;
 	uint32_t * V;
 	uint32_t * XY;
 	uint32_t i;

 	/* Sanity-check parameters. */
 #if SIZE_MAX > UINT32_MAX
 	if (buflen > (((uint64_t)(1) << 32) - 1) * 32) {
 		errno = EFBIG;
 		goto err0;
 	}
 #endif
 	if ((uint64_t)(r) * (uint64_t)(p) >= (1 << 30)) {
 		errno = EFBIG;
 		goto err0;
 	}
 	if (((N & (N - 1)) != 0) || (N == 0)) {
 		errno = EINVAL;
 		goto err0;
 	}
 	if ((r > SIZE_MAX / 128 / p) ||
 #if SIZE_MAX / 256 <= UINT32_MAX
 	    (r > (SIZE_MAX - 64) / 256) ||
 #endif
 	    (N > SIZE_MAX / 128 / r)) {
 		errno = ENOMEM;
 		goto err0;
 	}

 	/* Allocate memory. */
 #ifdef HAVE_POSIX_MEMALIGN
 	if ((errno = posix_memalign(&B0, 64, 128 * r * p)) != 0)
 		goto err0;
 	B = (uint8_t *)(B0);
 	if ((errno = posix_memalign(&XY0, 64, 256 * r + 64)) != 0)
 		goto err1;
 	XY = (uint32_t *)(XY0);
 #ifndef MAP_ANON
 	if ((errno = posix_memalign(&V0, 64, 128 * r * N)) != 0)
 		goto err2;
 	V = (uint32_t *)(V0);
 #endif
 #else
 	if ((B0 = malloc(128 * r * p + 63)) == NULL)
 		goto err0;
 	B = (uint8_t *)(((uintptr_t)(B0) + 63) & ~ (uintptr_t)(63));
 	if ((XY0 = malloc(256 * r + 64 + 63)) == NULL)
 		goto err1;
 	XY = (uint32_t *)(((uintptr_t)(XY0) + 63) & ~ (uintptr_t)(63));
 #ifndef MAP_ANON
 	if ((V0 = malloc(128 * r * N + 63)) == NULL)
 		goto err2;
 	V = (uint32_t *)(((uintptr_t)(V0) + 63) & ~ (uintptr_t)(63));
 #endif
 #endif
 #ifdef MAP_ANON
 	if ((V0 = mmap(NULL, 128 * r * N, PROT_READ | PROT_WRITE,
 #ifdef MAP_NOCORE
 	    MAP_ANON | MAP_PRIVATE | MAP_NOCORE,
 #else
 	    MAP_ANON | MAP_PRIVATE,
 #endif
 	    -1, 0)) == MAP_FAILED)
 		goto err2;
 	V = (uint32_t *)(V0);
 #endif

 	/* 1: (B_0 ... B_{p-1}) <-- PBKDF2(P, S, 1, p * MFLen) */
 	PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r);

 	/* 2: for i = 0 to p - 1 do */
 	for (i = 0; i < p; i++) {
 		/* 3: B_i <-- MF(B_i, N) */
 		smix(&B[i * 128 * r], r, N, V, XY);
 	}

 	/* 5: DK <-- PBKDF2(P, B, 1, dkLen) */
 	PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen);

 	/* Free memory. */
 #ifdef MAP_ANON
 	if (munmap(V0, 128 * r * N))
 		goto err2;
 #else
 	free(V0);
 #endif
 	free(XY0);
 	free(B0);

 	/* Success! */
 	return (0);

 err2:
 	free(XY0);
 err1:
 	free(B0);
 err0:
 	/* Failure! */
 	return (-1);
 }
	/*-
	* Copyright 2009 Colin Percival
	* 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.
	*
	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
	*
	* This file was originally written by Colin Percival as part of the Tarsnap
	* online backup system.
	*/
	#include "scrypt_platform.h"

	#include <sys/types.h>
	#include <sys/mman.h>

	#include <emmintrin.h>
	#include <errno.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>

	#include "sha256.h"
	#include "sysendian.h"

	#include "crypto_scrypt.h"

	static void blkcpy(void , void , size_t);
	static void blkxor(void , void , size_t);
	static void salsa20_8(__m128i *);
	static void blockmix_salsa8(__m128i , __m128i , __m128i *, size_t);
	static uint64_t integerify(void *, size_t);
	static void smix(uint8_t , size_t, uint64_t, void , void *);

	static void
	blkcpy(void * dest, void * src, size_t len)
	{
	__m128i * D = dest;
	__m128i * S = src;
	size_t L = len / 16;
	size_t i;

	for (i = 0; i < L; i++)
	D[i] = S[i];
	}

	static void
	blkxor(void * dest, void * src, size_t len)
	{
	__m128i * D = dest;
	__m128i * S = src;
	size_t L = len / 16;
	size_t i;

	for (i = 0; i < L; i++)
	D[i] = _mm_xor_si128(D[i], S[i]);
	}

	/**
	* salsa20_8(B):
	* Apply the salsa20/8 core to the provided block.
	*/
	static void
	salsa20_8(__m128i B[4])
	{
	__m128i X0, X1, X2, X3;
	__m128i T;
	size_t i;

	X0 = B[0];
	X1 = B[1];
	X2 = B[2];
	X3 = B[3];

	for (i = 0; i < 8; i += 2) {
	/* Operate on "columns". */
	T = _mm_add_epi32(X0, X3);
	X1 = _mm_xor_si128(X1, _mm_slli_epi32(T, 7));
	X1 = _mm_xor_si128(X1, _mm_srli_epi32(T, 25));
	T = _mm_add_epi32(X1, X0);
	X2 = _mm_xor_si128(X2, _mm_slli_epi32(T, 9));
	X2 = _mm_xor_si128(X2, _mm_srli_epi32(T, 23));
	T = _mm_add_epi32(X2, X1);
	X3 = _mm_xor_si128(X3, _mm_slli_epi32(T, 13));
	X3 = _mm_xor_si128(X3, _mm_srli_epi32(T, 19));
	T = _mm_add_epi32(X3, X2);
	X0 = _mm_xor_si128(X0, _mm_slli_epi32(T, 18));
	X0 = _mm_xor_si128(X0, _mm_srli_epi32(T, 14));

	/* Rearrange data. */
	X1 = _mm_shuffle_epi32(X1, 0x93);
	X2 = _mm_shuffle_epi32(X2, 0x4E);
	X3 = _mm_shuffle_epi32(X3, 0x39);

	/* Operate on "rows". */
	T = _mm_add_epi32(X0, X1);
	X3 = _mm_xor_si128(X3, _mm_slli_epi32(T, 7));
	X3 = _mm_xor_si128(X3, _mm_srli_epi32(T, 25));
	T = _mm_add_epi32(X3, X0);
	X2 = _mm_xor_si128(X2, _mm_slli_epi32(T, 9));
	X2 = _mm_xor_si128(X2, _mm_srli_epi32(T, 23));
	T = _mm_add_epi32(X2, X3);
	X1 = _mm_xor_si128(X1, _mm_slli_epi32(T, 13));
	X1 = _mm_xor_si128(X1, _mm_srli_epi32(T, 19));
	T = _mm_add_epi32(X1, X2);
	X0 = _mm_xor_si128(X0, _mm_slli_epi32(T, 18));
	X0 = _mm_xor_si128(X0, _mm_srli_epi32(T, 14));

	/* Rearrange data. */
	X1 = _mm_shuffle_epi32(X1, 0x39);
	X2 = _mm_shuffle_epi32(X2, 0x4E);
	X3 = _mm_shuffle_epi32(X3, 0x93);
	}

	B[0] = _mm_add_epi32(B[0], X0);
	B[1] = _mm_add_epi32(B[1], X1);
	B[2] = _mm_add_epi32(B[2], X2);
	B[3] = _mm_add_epi32(B[3], X3);
	}

	/**
	* blockmix_salsa8(Bin, Bout, X, r):
	* Compute Bout = BlockMix_{salsa20/8, r}(Bin). The input Bin must be 128r
	* bytes in length; the output Bout must also be the same size. The
	* temporary space X must be 64 bytes.
	*/
	static void
	blockmix_salsa8(__m128i * Bin, __m128i * Bout, __m128i * X, size_t r)
	{
	size_t i;

	/* 1: X <-- B_{2r - 1} */
	blkcpy(X, &Bin[8 * r - 4], 64);

	/* 2: for i = 0 to 2r - 1 do */
	for (i = 0; i < r; i++) {
	/* 3: X <-- H(X \xor B_i) */
	blkxor(X, &Bin[i * 8], 64);
	salsa20_8(X);

	/* 4: Y_i <-- X */
	/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
	blkcpy(&Bout[i * 4], X, 64);

	/* 3: X <-- H(X \xor B_i) */
	blkxor(X, &Bin[i * 8 + 4], 64);
	salsa20_8(X);

	/* 4: Y_i <-- X */
	/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
	blkcpy(&Bout[(r + i) * 4], X, 64);
	}
	}

	/**
	* integerify(B, r):
	* Return the result of parsing B_{2r-1} as a little-endian integer.
	*/
	static uint64_t
	integerify(void * B, size_t r)
	{
	uint32_t * X = (void )((uintptr_t)(B) + (2 r - 1) * 64);

	return (((uint64_t)(X[13]) << 32) + X[0]);
	}

	/**
	* smix(B, r, N, V, XY):
	* Compute B = SMix_r(B, N). The input B must be 128r bytes in length;
	* the temporary storage V must be 128rN bytes in length; the temporary
	* storage XY must be 256r + 64 bytes in length. The value N must be a
	* power of 2 greater than 1. The arrays B, V, and XY must be aligned to a
	* multiple of 64 bytes.
	*/
	static void
	smix(uint8_t * B, size_t r, uint64_t N, void * V, void * XY)
	{
	__m128i * X = XY;
	__m128i * Y = (void )((uintptr_t)(XY) + 128 r);
	__m128i * Z = (void )((uintptr_t)(XY) + 256 r);
	uint32_t * X32 = (void *)X;
	uint64_t i, j;
	size_t k;

	/* 1: X <-- B */
	for (k = 0; k < 2 * r; k++) {
	for (i = 0; i < 16; i++) {
	X32[k * 16 + i] =
	le32dec(&B[(k * 16 + (i * 5 % 16)) * 4]);
	}
	}

	/* 2: for i = 0 to N - 1 do */
	for (i = 0; i < N; i += 2) {
	/* 3: V_i <-- X */
	blkcpy((void )((uintptr_t)(V) + i 128 * r), X, 128 * r);

	/* 4: X <-- H(X) */
	blockmix_salsa8(X, Y, Z, r);

	/* 3: V_i <-- X */
	blkcpy((void )((uintptr_t)(V) + (i + 1) 128 * r),
	Y, 128 * r);

	/* 4: X <-- H(X) */
	blockmix_salsa8(Y, X, Z, r);
	}

	/* 6: for i = 0 to N - 1 do */
	for (i = 0; i < N; i += 2) {
	/* 7: j <-- Integerify(X) mod N */
	j = integerify(X, r) & (N - 1);

	/* 8: X <-- H(X \xor V_j) */
	blkxor(X, (void )((uintptr_t)(V) + j 128 * r), 128 * r);
	blockmix_salsa8(X, Y, Z, r);

	/* 7: j <-- Integerify(X) mod N */
	j = integerify(Y, r) & (N - 1);

	/* 8: X <-- H(X \xor V_j) */
	blkxor(Y, (void )((uintptr_t)(V) + j 128 * r), 128 * r);
	blockmix_salsa8(Y, X, Z, r);
	}

	/* 10: B' <-- X */
	for (k = 0; k < 2 * r; k++) {
	for (i = 0; i < 16; i++) {
	le32enc(&B[(k * 16 + (i * 5 % 16)) * 4],
	X32[k * 16 + i]);
	}
	}
	}

	/**
	* crypto_scrypt(passwd, passwdlen, salt, saltlen, N, r, p, buf, buflen):
	* Compute scrypt(passwd[0 .. passwdlen - 1], salt[0 .. saltlen - 1], N, r,
	* p, buflen) and write the result into buf. The parameters r, p, and buflen
	* must satisfy r * p < 2^30 and buflen <= (2^32 - 1) * 32. The parameter N
	* must be a power of 2 greater than 1.
	*
	* Return 0 on success; or -1 on error.
	*/
	int
	crypto_scrypt(const uint8_t * passwd, size_t passwdlen,
	const uint8_t * salt, size_t saltlen, uint64_t N, uint32_t r, uint32_t p,
	uint8_t * buf, size_t buflen)
	{
	void * B0, * V0, * XY0;
	uint8_t * B;
	uint32_t * V;
	uint32_t * XY;
	uint32_t i;

	/* Sanity-check parameters. */
	#if SIZE_MAX > UINT32_MAX
	if (buflen > (((uint64_t)(1) << 32) - 1) * 32) {
	errno = EFBIG;
	goto err0;
	}
	#endif
	if ((uint64_t)(r) * (uint64_t)(p) >= (1 << 30)) {
	errno = EFBIG;
	goto err0;
	}
	if (((N & (N - 1)) != 0) \|\| (N == 0)) {
	errno = EINVAL;
	goto err0;
	}
	if ((r > SIZE_MAX / 128 / p) \|\|
	#if SIZE_MAX / 256 <= UINT32_MAX
	(r > (SIZE_MAX - 64) / 256) \|\|
	#endif
	(N > SIZE_MAX / 128 / r)) {
	errno = ENOMEM;
	goto err0;
	}

	/* Allocate memory. */
	#ifdef HAVE_POSIX_MEMALIGN
	if ((errno = posix_memalign(&B0, 64, 128 * r * p)) != 0)
	goto err0;
	B = (uint8_t *)(B0);
	if ((errno = posix_memalign(&XY0, 64, 256 * r + 64)) != 0)
	goto err1;
	XY = (uint32_t *)(XY0);
	#ifndef MAP_ANON
	if ((errno = posix_memalign(&V0, 64, 128 * r * N)) != 0)
	goto err2;
	V = (uint32_t *)(V0);
	#endif
	#else
	if ((B0 = malloc(128 * r * p + 63)) == NULL)
	goto err0;
	B = (uint8_t *)(((uintptr_t)(B0) + 63) & ~ (uintptr_t)(63));
	if ((XY0 = malloc(256 * r + 64 + 63)) == NULL)
	goto err1;
	XY = (uint32_t *)(((uintptr_t)(XY0) + 63) & ~ (uintptr_t)(63));
	#ifndef MAP_ANON
	if ((V0 = malloc(128 * r * N + 63)) == NULL)
	goto err2;
	V = (uint32_t *)(((uintptr_t)(V0) + 63) & ~ (uintptr_t)(63));
	#endif
	#endif
	#ifdef MAP_ANON
	if ((V0 = mmap(NULL, 128 * r * N, PROT_READ \| PROT_WRITE,
	#ifdef MAP_NOCORE
	MAP_ANON \| MAP_PRIVATE \| MAP_NOCORE,
	#else
	MAP_ANON \| MAP_PRIVATE,
	#endif
	-1, 0)) == MAP_FAILED)
	goto err2;
	V = (uint32_t *)(V0);
	#endif

	/* 1: (B_0 ... B_{p-1}) <-- PBKDF2(P, S, 1, p * MFLen) */
	PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r);

	/* 2: for i = 0 to p - 1 do */
	for (i = 0; i < p; i++) {
	/* 3: B_i <-- MF(B_i, N) */
	smix(&B[i * 128 * r], r, N, V, XY);
	}

	/* 5: DK <-- PBKDF2(P, B, 1, dkLen) */
	PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen);

	/* Free memory. */
	#ifdef MAP_ANON
	if (munmap(V0, 128 * r * N))
	goto err2;
	#else
	free(V0);
	#endif
	free(XY0);
	free(B0);

	/* Success! */
	return (0);

	err2:
	free(XY0);
	err1:
	free(B0);
	err0:
	/* Failure! */
	return (-1);
	}