1 /*
2 * Copyright (c) 2019, 2020, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
8 *
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 */
23
24 import java.security.*;
25 import java.security.spec.*;
26 import java.math.*;
27 import java.util.*;
28
29 /*
30 * @test
31 * @bug 8147502
32 * @summary Test that digests are properly truncated before the signature
33 * is applied. The digest should be truncated to the bit length of the
34 * group order.
35 * @library /test/lib
36 * @build jdk.test.lib.Convert
37 * @run main/othervm -Djdk.sunec.disableNative=false SignatureDigestTruncate
38 */
39 public class SignatureDigestTruncate {
40
41 /*
42 * A SecureRandom that produces nextBytes in a way that causes the nonce
43 * to be set to the value supplied to the constructor. This class
44 * is specific to the way that the native ECDSA implementation in
45 * SunEC produces nonces from random input. It may not work for all
46 * test cases, and it will need to be updated when the behavior of
47 * SunEC changes.
48 */
49 private static class FixedRandom extends SecureRandom {
50
51 private final byte[] val;
52
53 public FixedRandom(byte[] val) {
54 // SunEC adds one to the value returned, so subtract one here in
55 // order to get back to the correct value.
56 BigInteger biVal = new BigInteger(1, val);
57 biVal = biVal.subtract(BigInteger.ONE);
58 byte[] temp = biVal.toByteArray();
59 this.val = new byte[val.length];
60 int inStartPos = Math.max(0, temp.length - val.length);
61 int outStartPos = Math.max(0, val.length - temp.length);
62 System.arraycopy(temp, inStartPos, this.val, outStartPos,
63 temp.length - inStartPos);
64 }
65
66 @Override
67 public void nextBytes(byte[] bytes) {
68 // SunEC samples (n + 1) * 2 bytes, but only n*2 bytes are used by
69 // the native implementation. So the value must be offset slightly.
70 Arrays.fill(bytes, (byte) 0);
71 int copyLength = Math.min(val.length, bytes.length - 2);
72 System.arraycopy(val, 0, bytes, bytes.length - copyLength - 2,
73 copyLength);
74 }
75 }
76
77 private static void assertEquals(byte[] expected, byte[] actual,
78 String name) {
79 if (!Arrays.equals(actual, expected)) {
80 System.out.println("expect: " + Hex.encoder().encode(expected));
81 System.out.println("actual: " + Hex.encoder().encode(actual));
82 throw new RuntimeException("Incorrect " + name + " value");
83 }
84 }
85
86 private static void runTest(String alg, String curveName,
87 String privateKeyStr, String msgStr, String kStr, String sigStr)
88 throws Exception {
89
90 System.out.println("Testing " + alg + " with " + curveName);
91
92 Hex.Decoder decoder = Hex.decoder();
93 byte[] privateKey = decoder.decode(privateKeyStr);
94 byte[] msg = decoder.decode(msgStr);
95 byte[] k = decoder.decode(kStr);
96 byte[] expectedSig = decoder.decode(sigStr);
97
98 AlgorithmParameters params =
99 AlgorithmParameters.getInstance("EC", "SunEC");
100 params.init(new ECGenParameterSpec(curveName));
101 ECParameterSpec ecParams =
102 params.getParameterSpec(ECParameterSpec.class);
103
104 KeyFactory kf = KeyFactory.getInstance("EC", "SunEC");
105 BigInteger s = new BigInteger(1, privateKey);
106 ECPrivateKeySpec privKeySpec = new ECPrivateKeySpec(s, ecParams);
107 PrivateKey privKey = kf.generatePrivate(privKeySpec);
108
109 Signature sig = Signature.getInstance(alg, "SunEC");
110 sig.initSign(privKey, new FixedRandom(k));
111 sig.update(msg);
112 byte[] computedSig = sig.sign();
113 assertEquals(expectedSig, computedSig, "signature");
114 }
115
116 public static void main(String[] args) throws Exception {
117 runTest("SHA384withECDSAinP1363Format", "sect283r1",
118 "abcdef10234567", "010203040506070809",
119 "000102030405060708090a0b0c0d0e0f101112131415161718191a1b1c1d" +
120 "1e1f20212223",
121 "01d7544b5d3935216bd45e2f8042537e1e0296a11e0eb96666199281b409" +
122 "42abccd5358a035de8a314d3e6c2a97614daebf5fb1313540eec3f9a3272" +
123 "068aa10922ccae87d255c84c");
124 }
125 }