src/lib/crypto/crypto_scrypt-ref.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 <errno.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <string.h>

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

 #include "crypto_scrypt.h"

 static void blkcpy(uint8_t *, uint8_t *, size_t);
 static void blkxor(uint8_t *, uint8_t *, size_t);
 static void salsa20_8(uint8_t[64]);
 static void blockmix_salsa8(uint8_t *, uint8_t *, size_t);
 static uint64_t integerify(uint8_t *, size_t);
 static void smix(uint8_t *, size_t, uint64_t, uint8_t *, uint8_t *);

 static void
 blkcpy(uint8_t * dest, uint8_t * src, size_t len)
 {
 	size_t i;

 	for (i = 0; i < len; i++)
 		dest[i] = src[i];
 }

 static void
 blkxor(uint8_t * dest, uint8_t * src, size_t len)
 {
 	size_t i;

 	for (i = 0; i < len; i++)
 		dest[i] ^= src[i];
 }

 /**
  * salsa20_8(B):
  * Apply the salsa20/8 core to the provided block.
  */
 static void
 salsa20_8(uint8_t B[64])
 {
 	uint32_t B32[16];
 	uint32_t x[16];
 	size_t i;

 	/* Convert little-endian values in. */
 	for (i = 0; i < 16; i++)
 		B32[i] = le32dec(&B[i * 4]);

 	/* Compute x = doubleround^4(B32). */
 	for (i = 0; i < 16; i++)
 		x[i] = B32[i];
 	for (i = 0; i < 8; i += 2) {
 #define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
 		/* Operate on columns. */
 		x[ 4] ^= R(x[ 0]+x[12], 7);  x[ 8] ^= R(x[ 4]+x[ 0], 9);
 		x[12] ^= R(x[ 8]+x[ 4],13);  x[ 0] ^= R(x[12]+x[ 8],18);

 		x[ 9] ^= R(x[ 5]+x[ 1], 7);  x[13] ^= R(x[ 9]+x[ 5], 9);
 		x[ 1] ^= R(x[13]+x[ 9],13);  x[ 5] ^= R(x[ 1]+x[13],18);

 		x[14] ^= R(x[10]+x[ 6], 7);  x[ 2] ^= R(x[14]+x[10], 9);
 		x[ 6] ^= R(x[ 2]+x[14],13);  x[10] ^= R(x[ 6]+x[ 2],18);

 		x[ 3] ^= R(x[15]+x[11], 7);  x[ 7] ^= R(x[ 3]+x[15], 9);
 		x[11] ^= R(x[ 7]+x[ 3],13);  x[15] ^= R(x[11]+x[ 7],18);

 		/* Operate on rows. */
 		x[ 1] ^= R(x[ 0]+x[ 3], 7);  x[ 2] ^= R(x[ 1]+x[ 0], 9);
 		x[ 3] ^= R(x[ 2]+x[ 1],13);  x[ 0] ^= R(x[ 3]+x[ 2],18);

 		x[ 6] ^= R(x[ 5]+x[ 4], 7);  x[ 7] ^= R(x[ 6]+x[ 5], 9);
 		x[ 4] ^= R(x[ 7]+x[ 6],13);  x[ 5] ^= R(x[ 4]+x[ 7],18);

 		x[11] ^= R(x[10]+x[ 9], 7);  x[ 8] ^= R(x[11]+x[10], 9);
 		x[ 9] ^= R(x[ 8]+x[11],13);  x[10] ^= R(x[ 9]+x[ 8],18);

 		x[12] ^= R(x[15]+x[14], 7);  x[13] ^= R(x[12]+x[15], 9);
 		x[14] ^= R(x[13]+x[12],13);  x[15] ^= R(x[14]+x[13],18);
 #undef R
 	}

 	/* Compute B32 = B32 + x. */
 	for (i = 0; i < 16; i++)
 		B32[i] += x[i];

 	/* Convert little-endian values out. */
 	for (i = 0; i < 16; i++)
 		le32enc(&B[4 * i], B32[i]);
 }

 /**
  * blockmix_salsa8(B, Y, r):
  * Compute B = BlockMix_{salsa20/8, r}(B).  The input B must be 128r bytes in
  * length; the temporary space Y must also be the same size.
  */
 static void
 blockmix_salsa8(uint8_t * B, uint8_t * Y, size_t r)
 {
 	uint8_t X[64];
 	size_t i;

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

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

 		/* 4: Y_i <-- X */
 		blkcpy(&Y[i * 64], X, 64);
 	}

 	/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
 	for (i = 0; i < r; i++)
 		blkcpy(&B[i * 64], &Y[(i * 2) * 64], 64);
 	for (i = 0; i < r; i++)
 		blkcpy(&B[(i + r) * 64], &Y[(i * 2 + 1) * 64], 64);
 }

 /**
  * integerify(B, r):
  * Return the result of parsing B_{2r-1} as a little-endian integer.
  */
 static uint64_t
 integerify(uint8_t * B, size_t r)
 {
 	uint8_t * X = &B[(2 * r - 1) * 64];

 	return (le64dec(X));
 }

 /**
  * 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 bytes in length.  The value N must be a power of 2.
  */
 static void
 smix(uint8_t * B, size_t r, uint64_t N, uint8_t * V, uint8_t * XY)
 {
 	uint8_t * X = XY;
 	uint8_t * Y = &XY[128 * r];
 	uint64_t i;
 	uint64_t j;

 	/* 1: X <-- B */
 	blkcpy(X, B, 128 * r);

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

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

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

 		/* 8: X <-- H(X \xor V_j) */
 		blkxor(X, &V[j * (128 * r)], 128 * r);
 		blockmix_salsa8(X, Y, r);
 	}

 	/* 10: B' <-- X */
 	blkcpy(B, X, 128 * r);
 }

 /**
  * 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.
  *
  * 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)
 {
 	uint8_t * B;
 	uint8_t * V;
 	uint8_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 / 256) ||
 #endif
 	    (N > SIZE_MAX / 128 / r)) {
 		errno = ENOMEM;
 		goto err0;
 	}

 	/* Allocate memory. */
 	if ((B = malloc(128 * r * p)) == NULL)
 		goto err0;
 	if ((XY = malloc(256 * r)) == NULL)
 		goto err1;
 	if ((V = malloc(128 * r * N)) == NULL)
 		goto err2;

 	/* 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. */
 	free(V);
 	free(XY);
 	free(B);

 	/* Success! */
 	return (0);

 err2:
 	free(XY);
 err1:
 	free(B);
 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 <errno.h>
	#include <stdint.h>
	#include <stdlib.h>
	#include <string.h>

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

	#include "crypto_scrypt.h"

	static void blkcpy(uint8_t , uint8_t , size_t);
	static void blkxor(uint8_t , uint8_t , size_t);
	static void salsa20_8(uint8_t[64]);
	static void blockmix_salsa8(uint8_t , uint8_t , size_t);
	static uint64_t integerify(uint8_t *, size_t);
	static void smix(uint8_t , size_t, uint64_t, uint8_t , uint8_t *);

	static void
	blkcpy(uint8_t * dest, uint8_t * src, size_t len)
	{
	size_t i;

	for (i = 0; i < len; i++)
	dest[i] = src[i];
	}

	static void
	blkxor(uint8_t * dest, uint8_t * src, size_t len)
	{
	size_t i;

	for (i = 0; i < len; i++)
	dest[i] ^= src[i];
	}

	/**
	* salsa20_8(B):
	* Apply the salsa20/8 core to the provided block.
	*/
	static void
	salsa20_8(uint8_t B[64])
	{
	uint32_t B32[16];
	uint32_t x[16];
	size_t i;

	/* Convert little-endian values in. */
	for (i = 0; i < 16; i++)
	B32[i] = le32dec(&B[i * 4]);

	/* Compute x = doubleround^4(B32). */
	for (i = 0; i < 16; i++)
	x[i] = B32[i];
	for (i = 0; i < 8; i += 2) {
	#define R(a,b) (((a) << (b)) \| ((a) >> (32 - (b))))
	/* Operate on columns. */
	x[ 4] ^= R(x[ 0]+x[12], 7); x[ 8] ^= R(x[ 4]+x[ 0], 9);
	x[12] ^= R(x[ 8]+x[ 4],13); x[ 0] ^= R(x[12]+x[ 8],18);

	x[ 9] ^= R(x[ 5]+x[ 1], 7); x[13] ^= R(x[ 9]+x[ 5], 9);
	x[ 1] ^= R(x[13]+x[ 9],13); x[ 5] ^= R(x[ 1]+x[13],18);

	x[14] ^= R(x[10]+x[ 6], 7); x[ 2] ^= R(x[14]+x[10], 9);
	x[ 6] ^= R(x[ 2]+x[14],13); x[10] ^= R(x[ 6]+x[ 2],18);

	x[ 3] ^= R(x[15]+x[11], 7); x[ 7] ^= R(x[ 3]+x[15], 9);
	x[11] ^= R(x[ 7]+x[ 3],13); x[15] ^= R(x[11]+x[ 7],18);

	/* Operate on rows. */
	x[ 1] ^= R(x[ 0]+x[ 3], 7); x[ 2] ^= R(x[ 1]+x[ 0], 9);
	x[ 3] ^= R(x[ 2]+x[ 1],13); x[ 0] ^= R(x[ 3]+x[ 2],18);

	x[ 6] ^= R(x[ 5]+x[ 4], 7); x[ 7] ^= R(x[ 6]+x[ 5], 9);
	x[ 4] ^= R(x[ 7]+x[ 6],13); x[ 5] ^= R(x[ 4]+x[ 7],18);

	x[11] ^= R(x[10]+x[ 9], 7); x[ 8] ^= R(x[11]+x[10], 9);
	x[ 9] ^= R(x[ 8]+x[11],13); x[10] ^= R(x[ 9]+x[ 8],18);

	x[12] ^= R(x[15]+x[14], 7); x[13] ^= R(x[12]+x[15], 9);
	x[14] ^= R(x[13]+x[12],13); x[15] ^= R(x[14]+x[13],18);
	#undef R
	}

	/* Compute B32 = B32 + x. */
	for (i = 0; i < 16; i++)
	B32[i] += x[i];

	/* Convert little-endian values out. */
	for (i = 0; i < 16; i++)
	le32enc(&B[4 * i], B32[i]);
	}

	/**
	* blockmix_salsa8(B, Y, r):
	* Compute B = BlockMix_{salsa20/8, r}(B). The input B must be 128r bytes in
	* length; the temporary space Y must also be the same size.
	*/
	static void
	blockmix_salsa8(uint8_t * B, uint8_t * Y, size_t r)
	{
	uint8_t X[64];
	size_t i;

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

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

	/* 4: Y_i <-- X */
	blkcpy(&Y[i * 64], X, 64);
	}

	/* 6: B' <-- (Y_0, Y_2 ... Y_{2r-2}, Y_1, Y_3 ... Y_{2r-1}) */
	for (i = 0; i < r; i++)
	blkcpy(&B[i * 64], &Y[(i * 2) * 64], 64);
	for (i = 0; i < r; i++)
	blkcpy(&B[(i + r) * 64], &Y[(i * 2 + 1) * 64], 64);
	}

	/**
	* integerify(B, r):
	* Return the result of parsing B_{2r-1} as a little-endian integer.
	*/
	static uint64_t
	integerify(uint8_t * B, size_t r)
	{
	uint8_t * X = &B[(2 * r - 1) * 64];

	return (le64dec(X));
	}

	/**
	* 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 bytes in length. The value N must be a power of 2.
	*/
	static void
	smix(uint8_t * B, size_t r, uint64_t N, uint8_t * V, uint8_t * XY)
	{
	uint8_t * X = XY;
	uint8_t * Y = &XY[128 * r];
	uint64_t i;
	uint64_t j;

	/* 1: X <-- B */
	blkcpy(X, B, 128 * r);

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

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

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

	/* 8: X <-- H(X \xor V_j) */
	blkxor(X, &V[j * (128 * r)], 128 * r);
	blockmix_salsa8(X, Y, r);
	}

	/* 10: B' <-- X */
	blkcpy(B, X, 128 * r);
	}

	/**
	* 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.
	*
	* 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)
	{
	uint8_t * B;
	uint8_t * V;
	uint8_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 / 256) \|\|
	#endif
	(N > SIZE_MAX / 128 / r)) {
	errno = ENOMEM;
	goto err0;
	}

	/* Allocate memory. */
	if ((B = malloc(128 * r * p)) == NULL)
	goto err0;
	if ((XY = malloc(256 * r)) == NULL)
	goto err1;
	if ((V = malloc(128 * r * N)) == NULL)
	goto err2;

	/* 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. */
	free(V);
	free(XY);
	free(B);

	/* Success! */
	return (0);

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