| /* |
| * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 8183591 |
| * @summary Test decoding of DER length fields containing Integer.MAX_VALUE |
| * @run main TestMaxLengthDER |
| */ |
| |
| import java.io.*; |
| import java.math.*; |
| import java.security.*; |
| import java.security.spec.*; |
| |
| public class TestMaxLengthDER { |
| |
| public static void main(String[] args) throws Exception { |
| |
| String message = "Message"; |
| Signature sig = Signature.getInstance("SHA256withDSA"); |
| KeyPairGenerator kpg = KeyPairGenerator.getInstance("DSA"); |
| SecureRandom rnd = new SecureRandom(); |
| rnd.setSeed(1); |
| kpg.initialize(2048, rnd); |
| KeyPair kp = kpg.generateKeyPair(); |
| sig.initSign(kp.getPrivate()); |
| sig.update(message.getBytes()); |
| byte[] sigData = sig.sign(); |
| |
| // Set the length of the second integer to Integer.MAX_VALUE |
| // First copy all the signature data to the correct location |
| int lengthPos = sigData[3] + 5; |
| byte[] modifiedSigData = new byte[sigData.length + 4]; |
| System.arraycopy(sigData, 0, modifiedSigData, 0, lengthPos); |
| System.arraycopy(sigData, lengthPos + 1, modifiedSigData, |
| lengthPos + 5, sigData.length - (lengthPos + 1)); |
| |
| // Increase the length (in bytes) of the sequence to account for |
| // the larger length field |
| modifiedSigData[1] += 4; |
| |
| // Modify the length field |
| modifiedSigData[lengthPos] = (byte) 0x84; |
| modifiedSigData[lengthPos + 1] = (byte) 0x7F; |
| modifiedSigData[lengthPos + 2] = (byte) 0xFF; |
| modifiedSigData[lengthPos + 3] = (byte) 0xFF; |
| modifiedSigData[lengthPos + 4] = (byte) 0xFF; |
| |
| sig.initVerify(kp.getPublic()); |
| sig.update(message.getBytes()); |
| |
| try { |
| sig.verify(modifiedSigData); |
| throw new RuntimeException("No exception on misencoded signature"); |
| } catch (SignatureException ex) { |
| if (ex.getCause() instanceof EOFException) { |
| // this is expected |
| } else { |
| throw ex; |
| } |
| } |
| } |
| } |