* 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 <stdio.h>
#include <stdint.h>
#include <string.h>
#include <ByteOrder.h>
#include "pbkdf2.h"
#include "crypto_scrypt_smix.h"
static void blkcpy(void *, const void *, size_t);
static void blkxor(void *, const void *, size_t);
static void salsa20_8(uint32_t[16]);
static void blockmix_salsa8(const uint32_t *, uint32_t *, uint32_t *, size_t);
static uint64_t integerify(const void *, size_t);
static void
blkcpy(void * dest, const void * src, size_t len)
{
size_t * D = (size_t *)dest;
const size_t * S = (const size_t *)src;
size_t L = len / sizeof(size_t);
size_t i;
for (i = 0; i < L; i++)
D[i] = S[i];
}
static void
blkxor(void * dest, const void * src, size_t len)
{
size_t * D = (size_t *)dest;
const size_t * S = (const size_t *)src;
size_t L = len / sizeof(size_t);
size_t i;
for (i = 0; i < L; i++)
D[i] ^= S[i];
}
* salsa20_8(B):
* Apply the salsa20/8 core to the provided block.
*/
static void
salsa20_8(uint32_t B[16])
{
uint32_t x[16];
size_t i;
blkcpy(x, B, 64);
for (i = 0; i < 8; i += 2) {
#define R(a,b) (((a) << (b)) | ((a) >> (32 - (b))))
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);
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
}
for (i = 0; i < 16; i++)
B[i] += x[i];
}
* 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(const uint32_t * Bin, uint32_t * Bout, uint32_t * X, size_t r)
{
size_t i;
blkcpy(X, &Bin[(2 * r - 1) * 16], 64);
for (i = 0; i < 2 * r; i += 2) {
blkxor(X, &Bin[i * 16], 64);
salsa20_8(X);
blkcpy(&Bout[i * 8], X, 64);
blkxor(X, &Bin[i * 16 + 16], 64);
salsa20_8(X);
blkcpy(&Bout[i * 8 + r * 16], X, 64);
}
}
* integerify(B, r):
* Return the result of parsing B_{2r-1} as a little-endian integer.
*/
static uint64_t
integerify(const void * B, size_t r)
{
const uint32_t * X = (const uint32_t *)((uintptr_t)(B) + (2 * r - 1) * 64);
return (((uint64_t)(X[1]) << 32) + X[0]);
}
* crypto_scrypt_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.
*/
void
crypto_scrypt_smix(uint8_t * B, size_t r, uint64_t N, void * _V, void * XY)
{
uint32_t * X = (uint32_t *)XY;
uint32_t * Y = (uint32_t *)((uint8_t *)(XY) + 128 * r);
uint32_t * Z = (uint32_t *)((uint8_t *)(XY) + 256 * r);
uint32_t * V = (uint32_t *)_V;
uint64_t i;
uint64_t j;
size_t k;
for (k = 0; k < 32 * r; k++) {
X[k] = B_LENDIAN_TO_HOST_INT32(((uint32_t*)B)[k]);
}
for (i = 0; i < N; i += 2) {
blkcpy(&V[i * (32 * r)], X, 128 * r);
blockmix_salsa8(X, Y, Z, r);
blkcpy(&V[(i + 1) * (32 * r)], Y, 128 * r);
blockmix_salsa8(Y, X, Z, r);
}
for (i = 0; i < N; i += 2) {
j = integerify(X, r) & (N - 1);
blkxor(X, &V[j * (32 * r)], 128 * r);
blockmix_salsa8(X, Y, Z, r);
j = integerify(Y, r) & (N - 1);
blkxor(Y, &V[j * (32 * r)], 128 * r);
blockmix_salsa8(Y, X, Z, r);
}
for (k = 0; k < 32 * r; k++) {
uint32_t* B32 = &(reinterpret_cast<uint32_t*>(B)[k]);
*B32 = B_HOST_TO_LENDIAN_INT32(X[k]);
}
}
