+// Copyright (C) 2011 - Will Glozer. All rights reserved.
+
+package com.lambdaworks.crypto;
+
+import com.lambdaworks.jni.*;
+
+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 <a href="http://www.tarsnap.com/scrypt/scrypt.pdf"/>scrypt</a>
+ * key derivation function. This class will attempt to load a native library
+ * containing the optimized C implementation from
+ * <a href="http://www.tarsnap.com/scrypt.html">http://www.tarsnap.com/scrypt.html<a> and
+ * fall back to the pure Java version if that fails.
+ *
+ * @author Will Glozer
+ */
+public class SCrypt {
+ private static final boolean native_library_loaded;
+
+ static {
+ LibraryLoader loader = LibraryLoaders.loader();
+ native_library_loaded = loader.load("scrypt", true);
+ }
+
+ /**
+ * Implementation of the <a href="http://www.tarsnap.com/scrypt/scrypt.pdf"/>scrypt KDF</a>.
+ * 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 <a href="http://www.tarsnap.com/scrypt/scrypt.pdf"/>scrypt KDF</a> using
+ * the code from <a href="http://www.tarsnap.com/scrypt.html">http://www.tarsnap.com/scrypt.html<a>.
+ *
+ * @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, int N, int r, int p, int dkLen);
+
+ /**
+ * Pure Java implementation of the <a href="http://www.tarsnap.com/scrypt/scrypt.pdf"/>scrypt KDF</a>.
+ *
+ * @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 < 2 || (N & (N - 1)) != 0) throw new IllegalArgumentException("N must be a power of 2 greater than 1");
+
+ 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];
+ 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);
+ }
+
+ 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) {
+ 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);
+ }
+
+ 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);
+ }
+
+ arraycopy(XY, Xi, B, Bi, 128 * r);
+ }
+
+ public static void blockmix_salsa8(byte[] BY, int Bi, int Yi, int r) {
+ byte[] X = new byte[64];
+ 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);
+ 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 = new int[16];
+ int[] x = new int[16];
+ 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;
+ }
+}
projects / gigi.git / commitdiff