/*-
* 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>
#ifdef USE_OPENSSL_PBKDF2
#include <openssl/evp.h>
#else
#include "sha256.h"
#endif
#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) */
#ifdef USE_OPENSSL_PBKDF2
PKCS5_PBKDF2_HMAC((const char *)passwd, passwdlen, salt, saltlen, 1, EVP_sha256(), p * 128 * r, B);
#else
PBKDF2_SHA256(passwd, passwdlen, salt, saltlen, 1, B, p * 128 * r);
#endif
/* 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) */
#ifdef USE_OPENSSL_PBKDF2
PKCS5_PBKDF2_HMAC((const char *)passwd, passwdlen, B, p * 128 * r, 1, EVP_sha256(), buflen, buf);
#else
PBKDF2_SHA256(passwd, passwdlen, B, p * 128 * r, 1, buf, buflen);
#endif
/* 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);
}