com.lambdaworks.crypto.SCryptLessAlloc Maven / Gradle / Ivy
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Java implementation of scrypt
// Copyright (C) 2011 - Will Glozer. All rights reserved.
package com.lambdaworks.crypto;
import com.lambdaworks.jni.JarLibraryLoader;
import javax.crypto.Mac;
import javax.crypto.spec.SecretKeySpec;
import java.security.GeneralSecurityException;
import static java.lang.Integer.MAX_VALUE;
import static java.lang.System.arraycopy;
/**
* An implementation of the scrypt
* key derivation function. This class will attempt to load a native library
* containing the optimized C implementation from
* http://www.tarsnap.com/scrypt.html and
* fall back to the pure Java version if that fails.
*
* @author Will Glozer
*/
public class SCryptLessAlloc {
private static boolean native_library_loaded = false;
static {
JarLibraryLoader loader = new JarLibraryLoader();
native_library_loaded = loader.load("scrypt", true);
}
/**
* Implementation of the scrypt KDF.
* Calls the native implementation {@link #scryptN} when the native library was successfully
* loaded, otherwise calls {@link #scryptJ}.
*
* @param passwd Password.
* @param salt Salt.
* @param N CPU cost parameter.
* @param r Memory cost parameter.
* @param p Parallelization parameter.
* @param dkLen Intended length of the derived key.
*
* @return The derived key.
*
* @throws GeneralSecurityException when HMAC_SHA256 is not available.
*/
public static byte[] scrypt(byte[] passwd, byte[] salt, int N, int r, int p, int dkLen) throws GeneralSecurityException {
return native_library_loaded ? scryptN(passwd, salt, N, r, p, dkLen) : scryptJ(passwd, salt, N, r, p, dkLen);
}
/**
* Native C implementation of the scrypt KDF using
* the code from http://www.tarsnap.com/scrypt.html.
*
* @param passwd Password.
* @param salt Salt.
* @param N CPU cost parameter.
* @param r Memory cost parameter.
* @param p Parallelization parameter.
* @param dkLen Intended length of the derived key.
*
* @return The derived key.
*/
public static native byte[] scryptN(byte[] passwd, byte[] salt, long N, int r, int p, int dkLen);
/**
* Pure Java implementation of the scrypt KDF.
*
* @param passwd Password.
* @param salt Salt.
* @param N CPU cost parameter.
* @param r Memory cost parameter.
* @param p Parallelization parameter.
* @param dkLen Intended length of the derived key.
*
* @return The derived key.
*
* @throws GeneralSecurityException when HMAC_SHA256 is not available.
*/
public static byte[] scryptJ(byte[] passwd, byte[] salt, int N, int r, int p, int dkLen) throws GeneralSecurityException {
if (N == 0 || (N & (N - 1)) != 0) throw new IllegalArgumentException("N must be > 0 and a power of 2");
if (N > MAX_VALUE / 128 / r) throw new IllegalArgumentException("Parameter N is too large");
if (r > MAX_VALUE / 128 / p) throw new IllegalArgumentException("Parameter r is too large");
Mac mac = Mac.getInstance("HmacSHA256");
mac.init(new SecretKeySpec(passwd, "HmacSHA256"));
byte[] DK = new byte[dkLen];
byte[] B = new byte[128 * r * p];
byte[] XY = new byte[256 * r];
byte[] V = new byte[128 * r * N];
byte[] X = new byte[64];
int[] B32 = new int[16];
int[] salsaX = new int[16];
int i;
PBKDF.pbkdf2(mac, salt, 1, B, p * 128 * r);
for (i = 0; i < p; i++) {
smix(B, i * 128 * r, r, N, V, XY, X, B32, salsaX);
}
PBKDF.pbkdf2(mac, B, 1, DK, dkLen);
return DK;
}
public static void smix(byte[] B, int Bi, int r, int N, byte[] V, byte[] XY, byte[] X, int[] B32, int[] salsaX) {
int Xi = 0;
int Yi = 128 * r;
int i;
arraycopy(B, Bi, XY, Xi, 128 * r);
for (i = 0; i < N; i++) {
arraycopy(XY, Xi, V, i * (128 * r), 128 * r);
blockmix_salsa8(XY, Xi, Yi, r, X, B32, salsaX);
}
for (i = 0; i < N; i++) {
int j = integerify(XY, Xi, r) & (N - 1);
blockxor(V, j * (128 * r), XY, Xi, 128 * r);
blockmix_salsa8(XY, Xi, Yi, r, X, B32, salsaX);
}
arraycopy(XY, Xi, B, Bi, 128 * r);
}
public static void blockmix_salsa8(byte[] BY, int Bi, int Yi, int r, byte[] X, int[] B32, int[] salsaX) {
int i;
arraycopy(BY, Bi + (2 * r - 1) * 64, X, 0, 64);
for (i = 0; i < 2 * r; i++) {
blockxor(BY, i * 64, X, 0, 64);
salsa20_8(X, B32, salsaX);
arraycopy(X, 0, BY, Yi + (i * 64), 64);
}
for (i = 0; i < r; i++) {
arraycopy(BY, Yi + (i * 2) * 64, BY, Bi + (i * 64), 64);
}
for (i = 0; i < r; i++) {
arraycopy(BY, Yi + (i * 2 + 1) * 64, BY, Bi + (i + r) * 64, 64);
}
}
public static int R(int a, int b) {
return (a << b) | (a >>> (32 - b));
}
public static void salsa20_8(byte[] B, int[] B32, int[] x) {
int i;
for (i = 0; i < 16; i++) {
B32[i] = (B[i * 4 + 0] & 0xff) << 0;
B32[i] |= (B[i * 4 + 1] & 0xff) << 8;
B32[i] |= (B[i * 4 + 2] & 0xff) << 16;
B32[i] |= (B[i * 4 + 3] & 0xff) << 24;
}
arraycopy(B32, 0, x, 0, 16);
for (i = 8; i > 0; i -= 2) {
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);
}
for (i = 0; i < 16; ++i) B32[i] = x[i] + B32[i];
for (i = 0; i < 16; i++) {
B[i * 4 + 0] = (byte) (B32[i] >> 0 & 0xff);
B[i * 4 + 1] = (byte) (B32[i] >> 8 & 0xff);
B[i * 4 + 2] = (byte) (B32[i] >> 16 & 0xff);
B[i * 4 + 3] = (byte) (B32[i] >> 24 & 0xff);
}
}
public static void blockxor(byte[] S, int Si, byte[] D, int Di, int len) {
for (int i = 0; i < len; i++) {
D[Di + i] ^= S[Si + i];
}
}
public static int integerify(byte[] B, int Bi, int r) {
int n;
Bi += (2 * r - 1) * 64;
n = (B[Bi + 0] & 0xff) << 0;
n |= (B[Bi + 1] & 0xff) << 8;
n |= (B[Bi + 2] & 0xff) << 16;
n |= (B[Bi + 3] & 0xff) << 24;
return n;
}
}
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