The Tor Browser / file diff

     1.1 --- /dev/null	Thu Jan 01 00:00:00 1970 +0000
     1.2 +++ b/mobile/android/base/browserid/ASNUtils.java	Wed Dec 31 06:09:35 2014 +0100
     1.3 @@ -0,0 +1,82 @@
     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.browserid;
     1.9 +
    1.10 +
    1.11 +/**
    1.12 + * Java produces signature in ASN.1 format. Here's some hard-coded encoding and decoding
    1.13 + * code, courtesy of a comment in
    1.14 + * <a href="http://stackoverflow.com/questions/10921733/how-sign-method-of-the-digital-signature-combines-the-r-s-values-in-to-array">http://stackoverflow.com/questions/10921733/how-sign-method-of-the-digital-signature-combines-the-r-s-values-in-to-array</a>.
    1.15 + */
    1.16 +public class ASNUtils {
    1.17 +  /**
    1.18 +   * Decode two short arrays from ASN.1 bytes.
    1.19 +   * @param input to extract.
    1.20 +   * @return length 2 array of byte arrays.
    1.21 +   */
    1.22 +  public static byte[][] decodeTwoArraysFromASN1(byte[] input) throws IllegalArgumentException {
    1.23 +    if (input == null) {
    1.24 +      throw new IllegalArgumentException("input must not be null");
    1.25 +    }
    1.26 +    if (input.length <= 3)
    1.27 +      throw new IllegalArgumentException("bad length");
    1.28 +    if (input[0] != 0x30)
    1.29 +      throw new IllegalArgumentException("bad encoding");
    1.30 +    if ((input[1] & ((byte) 0x80)) != 0)
    1.31 +      throw new IllegalArgumentException("bad length encoding");
    1.32 +    if (input[2] != 0x02)
    1.33 +      throw new IllegalArgumentException("bad encoding");
    1.34 +    if ((input[3] & ((byte) 0x80)) != 0)
    1.35 +      throw new IllegalArgumentException("bad length encoding");
    1.36 +    byte rLength = input[3];
    1.37 +    if (input.length <= 5 + rLength)
    1.38 +      throw new IllegalArgumentException("bad length");
    1.39 +    if (input[4 + rLength] != 0x02)
    1.40 +      throw new IllegalArgumentException("bad encoding");
    1.41 +    if ((input[5 + rLength] & (byte) 0x80) !=0)
    1.42 +      throw new IllegalArgumentException("bad length encoding");
    1.43 +    byte sLength = input[5 + rLength];
    1.44 +    if (input.length != 6 + sLength + rLength)
    1.45 +      throw new IllegalArgumentException("bad length");
    1.46 +    byte[] rArr = new byte[rLength];
    1.47 +    byte[] sArr = new byte[sLength];
    1.48 +    System.arraycopy(input, 4, rArr, 0, rLength);
    1.49 +    System.arraycopy(input, 6 + rLength, sArr, 0, sLength);
    1.50 +    return new byte[][] { rArr, sArr };
    1.51 +  }
    1.52 +
    1.53 +  /**
    1.54 +   * Encode two short arrays into ASN.1 bytes.
    1.55 +   * @param first array to encode.
    1.56 +   * @param second array to encode.
    1.57 +   * @return array.
    1.58 +   */
    1.59 +  public static byte[] encodeTwoArraysToASN1(byte[] first, byte[] second) throws IllegalArgumentException {
    1.60 +    if (first == null) {
    1.61 +      throw new IllegalArgumentException("first must not be null");
    1.62 +    }
    1.63 +    if (second == null) {
    1.64 +      throw new IllegalArgumentException("second must not be null");
    1.65 +    }
    1.66 +    byte[] output = new byte[6 + first.length + second.length];
    1.67 +    output[0] = 0x30;
    1.68 +    if (4 + first.length + second.length > 255)
    1.69 +      throw new IllegalArgumentException("bad length");
    1.70 +    output[1] = (byte) (4 + first.length + second.length);
    1.71 +    if ((output[1] & ((byte) 0x80)) != 0)
    1.72 +      throw new IllegalArgumentException("bad length encoding");
    1.73 +    output[2] = 0x02;
    1.74 +    output[3] = (byte) first.length;
    1.75 +    if ((output[3] & ((byte) 0x80)) != 0)
    1.76 +      throw new IllegalArgumentException("bad length encoding");
    1.77 +    System.arraycopy(first, 0, output, 4, first.length);
    1.78 +    output[4 + first.length] = 0x02;
    1.79 +    output[5 + first.length] = (byte) second.length;
    1.80 +    if ((output[5 + first.length] & ((byte) 0x80)) != 0)
    1.81 +      throw new IllegalArgumentException("bad length encoding");
    1.82 +    System.arraycopy(second, 0, output, 6 + first.length, second.length);
    1.83 +    return output;
    1.84 +  }
    1.85 +}