1 /*
2  * Copyright (c) 1998, 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 /*
25  * @test
26  * @bug 4114896
27  * @summary Signature should support a sign() method that places the signature
28  * in an already existing array.
29  */
30 
31 import java.security.*;
32 
33 public class SignWithOutputBuffer {
34 
35     public static void main(String[] args) throws Exception {
36 
37         int numBytes;
38 
39         KeyPairGenerator kpGen = KeyPairGenerator.getInstance("DSA");
40         kpGen.initialize(512);
41         KeyPair kp = kpGen.genKeyPair();
42 
43         Signature sig = Signature.getInstance("DSS");
44         sig.initSign(kp.getPrivate());
45         sig.update((byte)0xff);
46 
47         // Allocate buffer for signature. According to BSAFE, the size of the
48         // signature may be as many as 48 bytes.
49         // First, let's allocate a buffer that's too short.
50         byte[] out = new byte[10];
51         try {
52             numBytes = sig.sign(out, 0, out.length);
53         } catch (SignatureException e) {
54             System.out.println(e);
55         }
56 
57         // Now repeat the same with a buffer that's big enough
58         sig = Signature.getInstance("DSS");
59         sig.initSign(kp.getPrivate());
60         sig.update((byte)0xff);
61         out = new byte[48];
62         numBytes = sig.sign(out, 0, out.length);
63 
64         System.out.println("Signature len="+numBytes);
65     }
66 }
67