01: /*
02: * @(#)NativeSeedGenerator.java 1.6 06/10/10
03: *
04: * Copyright 1990-2006 Sun Microsystems, Inc. All Rights Reserved.
05: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
06: *
07: * This program is free software; you can redistribute it and/or
08: * modify it under the terms of the GNU General Public License version
09: * 2 only, as published by the Free Software Foundation.
10: *
11: * This program is distributed in the hope that it will be useful, but
12: * WITHOUT ANY WARRANTY; without even the implied warranty of
13: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14: * General Public License version 2 for more details (a copy is
15: * included at /legal/license.txt).
16: *
17: * You should have received a copy of the GNU General Public License
18: * version 2 along with this work; if not, write to the Free Software
19: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
20: * 02110-1301 USA
21: *
22: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
23: * Clara, CA 95054 or visit www.sun.com if you need additional
24: * information or have any questions.
25: */
26:
27: package sun.security.provider;
28:
29: import java.io.IOException;
30:
31: /**
32: * Seed generator for Windows making use of MS CryptoAPI using native code.
33: *
34: * @version 1.6, 10/10/06
35: */
36: class NativeSeedGenerator extends SeedGenerator {
37:
38: /**
39: * Create a new CryptoAPI seed generator instances.
40: *
41: * @exception IOException if CryptoAPI seeds are not available
42: * on this platform.
43: */
44: NativeSeedGenerator() throws IOException {
45: super ();
46: // try generating two random bytes to see if CAPI is available
47: if (!nativeGenerateSeed(new byte[2])) {
48: throw new IOException(
49: "Required native CryptoAPI features not "
50: + " available on this machine");
51: }
52: }
53:
54: /**
55: * Native method to do the actual work.
56: */
57: private static native boolean nativeGenerateSeed(byte[] result);
58:
59: void getSeedBytes(byte[] result) {
60: // fill array as a side effect
61: if (nativeGenerateSeed(result) == false) {
62: // should never happen if constructor check succeeds
63: throw new InternalError(
64: "Unexpected CryptoAPI failure generating seed");
65: }
66: }
67:
68: byte getSeedByte() {
69: byte[] b = new byte[1];
70: getSeedBytes(b);
71: return b[0];
72: }
73: }
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