The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/mobile/android/base/sync/crypto/PBKDF2.java	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,78 @@
     1.4 +/* This Source Code Form is subject to the terms of the Mozilla Public
     1.5 + * License, v. 2.0. If a copy of the MPL was not distributed with this
     1.6 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
     1.7 +
     1.8 +package org.mozilla.gecko.sync.crypto;
     1.9 +
    1.10 +import java.security.GeneralSecurityException;
    1.11 +import java.util.Arrays;
    1.12 +
    1.13 +import javax.crypto.Mac;
    1.14 +import javax.crypto.ShortBufferException;
    1.15 +import javax.crypto.spec.SecretKeySpec;
    1.16 +
    1.17 +public class PBKDF2 {
    1.18 +  public static byte[] pbkdf2SHA256(byte[] password, byte[] salt, int c, int dkLen)
    1.19 +      throws GeneralSecurityException {
    1.20 +    final String algorithm = "HmacSHA256";
    1.21 +    SecretKeySpec keyspec = new SecretKeySpec(password, algorithm);
    1.22 +    Mac prf = Mac.getInstance(algorithm);
    1.23 +    prf.init(keyspec);
    1.24 +
    1.25 +    int hLen = prf.getMacLength();
    1.26 +
    1.27 +    byte U_r[] = new byte[hLen];
    1.28 +    byte U_i[] = new byte[salt.length + 4];
    1.29 +    byte scratch[] = new byte[hLen];
    1.30 +
    1.31 +    int l = Math.max(dkLen, hLen);
    1.32 +    int r = dkLen - (l - 1) * hLen;
    1.33 +    byte T[] = new byte[l * hLen];
    1.34 +    int ti_offset = 0;
    1.35 +    for (int i = 1; i <= l; i++) {
    1.36 +      Arrays.fill(U_r, (byte) 0);
    1.37 +      F(T, ti_offset, prf, salt, c, i, U_r, U_i, scratch);
    1.38 +      ti_offset += hLen;
    1.39 +    }
    1.40 +
    1.41 +    if (r < hLen) {
    1.42 +      // Incomplete last block.
    1.43 +      byte DK[] = new byte[dkLen];
    1.44 +      System.arraycopy(T, 0, DK, 0, dkLen);
    1.45 +      return DK;
    1.46 +    }
    1.47 +
    1.48 +    return T;
    1.49 +  }
    1.50 +
    1.51 +  private static void F(byte[] dest, int offset, Mac prf, byte[] S, int c, int blockIndex, byte U_r[], byte U_i[], byte[] scratch)
    1.52 +      throws ShortBufferException, IllegalStateException {
    1.53 +    final int hLen = prf.getMacLength();
    1.54 +
    1.55 +    // U0 = S || INT (i);
    1.56 +    System.arraycopy(S, 0, U_i, 0, S.length);
    1.57 +    INT(U_i, S.length, blockIndex);
    1.58 +
    1.59 +    for (int i = 0; i < c; i++) {
    1.60 +      prf.update(U_i);
    1.61 +      prf.doFinal(scratch, 0);
    1.62 +      U_i = scratch;
    1.63 +      xor(U_r, U_i);
    1.64 +    }
    1.65 +
    1.66 +    System.arraycopy(U_r, 0, dest, offset, hLen);
    1.67 +  }
    1.68 +
    1.69 +  private static void xor(byte[] dest, byte[] src) {
    1.70 +    for (int i = 0; i < dest.length; i++) {
    1.71 +      dest[i] ^= src[i];
    1.72 +    }
    1.73 +  }
    1.74 +
    1.75 +  private static void INT(byte[] dest, int offset, int i) {
    1.76 +    dest[offset + 0] = (byte) (i / (256 * 256 * 256));
    1.77 +    dest[offset + 1] = (byte) (i / (256 * 256));
    1.78 +    dest[offset + 2] = (byte) (i / (256));
    1.79 +    dest[offset + 3] = (byte) (i);
    1.80 +  }
    1.81 +}