mobile/android/base/browserid/ASNUtils.java@b8a032363ba2
mobile/android/base/browserid/ASNUtils.java
Thu, 22 Jan 2015 13:21:57 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Thu, 22 Jan 2015 13:21:57 +0100
- branch
- TOR_BUG_9701
- changeset 15
- b8a032363ba2
- permissions
- -rw-r--r--
Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6
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/. */
5 package org.mozilla.gecko.browserid;
8 /**
9 * Java produces signature in ASN.1 format. Here's some hard-coded encoding and decoding
10 * code, courtesy of a comment in
11 * <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>.
12 */
13 public class ASNUtils {
14 /**
15 * Decode two short arrays from ASN.1 bytes.
16 * @param input to extract.
17 * @return length 2 array of byte arrays.
18 */
19 public static byte[][] decodeTwoArraysFromASN1(byte[] input) throws IllegalArgumentException {
20 if (input == null) {
21 throw new IllegalArgumentException("input must not be null");
22 }
23 if (input.length <= 3)
24 throw new IllegalArgumentException("bad length");
25 if (input[0] != 0x30)
26 throw new IllegalArgumentException("bad encoding");
27 if ((input[1] & ((byte) 0x80)) != 0)
28 throw new IllegalArgumentException("bad length encoding");
29 if (input[2] != 0x02)
30 throw new IllegalArgumentException("bad encoding");
31 if ((input[3] & ((byte) 0x80)) != 0)
32 throw new IllegalArgumentException("bad length encoding");
33 byte rLength = input[3];
34 if (input.length <= 5 + rLength)
35 throw new IllegalArgumentException("bad length");
36 if (input[4 + rLength] != 0x02)
37 throw new IllegalArgumentException("bad encoding");
38 if ((input[5 + rLength] & (byte) 0x80) !=0)
39 throw new IllegalArgumentException("bad length encoding");
40 byte sLength = input[5 + rLength];
41 if (input.length != 6 + sLength + rLength)
42 throw new IllegalArgumentException("bad length");
43 byte[] rArr = new byte[rLength];
44 byte[] sArr = new byte[sLength];
45 System.arraycopy(input, 4, rArr, 0, rLength);
46 System.arraycopy(input, 6 + rLength, sArr, 0, sLength);
47 return new byte[][] { rArr, sArr };
48 }
50 /**
51 * Encode two short arrays into ASN.1 bytes.
52 * @param first array to encode.
53 * @param second array to encode.
54 * @return array.
55 */
56 public static byte[] encodeTwoArraysToASN1(byte[] first, byte[] second) throws IllegalArgumentException {
57 if (first == null) {
58 throw new IllegalArgumentException("first must not be null");
59 }
60 if (second == null) {
61 throw new IllegalArgumentException("second must not be null");
62 }
63 byte[] output = new byte[6 + first.length + second.length];
64 output[0] = 0x30;
65 if (4 + first.length + second.length > 255)
66 throw new IllegalArgumentException("bad length");
67 output[1] = (byte) (4 + first.length + second.length);
68 if ((output[1] & ((byte) 0x80)) != 0)
69 throw new IllegalArgumentException("bad length encoding");
70 output[2] = 0x02;
71 output[3] = (byte) first.length;
72 if ((output[3] & ((byte) 0x80)) != 0)
73 throw new IllegalArgumentException("bad length encoding");
74 System.arraycopy(first, 0, output, 4, first.length);
75 output[4 + first.length] = 0x02;
76 output[5 + first.length] = (byte) second.length;
77 if ((output[5 + first.length] & ((byte) 0x80)) != 0)
78 throw new IllegalArgumentException("bad length encoding");
79 System.arraycopy(second, 0, output, 6 + first.length, second.length);
80 return output;
81 }
82 }
