The Tor Browser / file comparison
comparison: mobile/android/base/sync/crypto/PBKDF2.java
mobile/android/base/sync/crypto/PBKDF2.java
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| 1 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 2 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 3 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 4 | |
| 5 package org.mozilla.gecko.sync.crypto; | |
| 6 | |
| 7 import java.security.GeneralSecurityException; | |
| 8 import java.util.Arrays; | |
| 9 | |
| 10 import javax.crypto.Mac; | |
| 11 import javax.crypto.ShortBufferException; | |
| 12 import javax.crypto.spec.SecretKeySpec; | |
| 13 | |
| 14 public class PBKDF2 { | |
| 15 public static byte[] pbkdf2SHA256(byte[] password, byte[] salt, int c, int dkLen) | |
| 16 throws GeneralSecurityException { | |
| 17 final String algorithm = "HmacSHA256"; | |
| 18 SecretKeySpec keyspec = new SecretKeySpec(password, algorithm); | |
| 19 Mac prf = Mac.getInstance(algorithm); | |
| 20 prf.init(keyspec); | |
| 21 | |
| 22 int hLen = prf.getMacLength(); | |
| 23 | |
| 24 byte U_r[] = new byte[hLen]; | |
| 25 byte U_i[] = new byte[salt.length + 4]; | |
| 26 byte scratch[] = new byte[hLen]; | |
| 27 | |
| 28 int l = Math.max(dkLen, hLen); | |
| 29 int r = dkLen - (l - 1) * hLen; | |
| 30 byte T[] = new byte[l * hLen]; | |
| 31 int ti_offset = 0; | |
| 32 for (int i = 1; i <= l; i++) { | |
| 33 Arrays.fill(U_r, (byte) 0); | |
| 34 F(T, ti_offset, prf, salt, c, i, U_r, U_i, scratch); | |
| 35 ti_offset += hLen; | |
| 36 } | |
| 37 | |
| 38 if (r < hLen) { | |
| 39 // Incomplete last block. | |
| 40 byte DK[] = new byte[dkLen]; | |
| 41 System.arraycopy(T, 0, DK, 0, dkLen); | |
| 42 return DK; | |
| 43 } | |
| 44 | |
| 45 return T; | |
| 46 } | |
| 47 | |
| 48 private static void F(byte[] dest, int offset, Mac prf, byte[] S, int c, int blockIndex, byte U_r[], byte U_i[], byte[] scratch) | |
| 49 throws ShortBufferException, IllegalStateException { | |
| 50 final int hLen = prf.getMacLength(); | |
| 51 | |
| 52 // U0 = S || INT (i); | |
| 53 System.arraycopy(S, 0, U_i, 0, S.length); | |
| 54 INT(U_i, S.length, blockIndex); | |
| 55 | |
| 56 for (int i = 0; i < c; i++) { | |
| 57 prf.update(U_i); | |
| 58 prf.doFinal(scratch, 0); | |
| 59 U_i = scratch; | |
| 60 xor(U_r, U_i); | |
| 61 } | |
| 62 | |
| 63 System.arraycopy(U_r, 0, dest, offset, hLen); | |
| 64 } | |
| 65 | |
| 66 private static void xor(byte[] dest, byte[] src) { | |
| 67 for (int i = 0; i < dest.length; i++) { | |
| 68 dest[i] ^= src[i]; | |
| 69 } | |
| 70 } | |
| 71 | |
| 72 private static void INT(byte[] dest, int offset, int i) { | |
| 73 dest[offset + 0] = (byte) (i / (256 * 256 * 256)); | |
| 74 dest[offset + 1] = (byte) (i / (256 * 256)); | |
| 75 dest[offset + 2] = (byte) (i / (256)); | |
| 76 dest[offset + 3] = (byte) (i); | |
| 77 } | |
| 78 } |
