01: /*
02: * Portions Copyright 2000-2007 Sun Microsystems, Inc. All Rights
03: * Reserved. Use is subject to license terms.
04: * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
05: *
06: * This program is free software; you can redistribute it and/or
07: * modify it under the terms of the GNU General Public License version
08: * 2 only, as published by the Free Software Foundation.
09: *
10: * This program is distributed in the hope that it will be useful, but
11: * WITHOUT ANY WARRANTY; without even the implied warranty of
12: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13: * General Public License version 2 for more details (a copy is
14: * included at /legal/license.txt).
15: *
16: * You should have received a copy of the GNU General Public License
17: * version 2 along with this work; if not, write to the Free Software
18: * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
19: * 02110-1301 USA
20: *
21: * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa
22: * Clara, CA 95054 or visit www.sun.com if you need additional
23: * information or have any questions.
24: */
25: package gov.nist.siplite;
26:
27: import gov.nist.core.*;
28: import java.util.Random;
29: import java.util.Date;
30:
31: /**
32: * SIP utility functions.
33: */
34: public class SIPUtils extends Utils {
35: /** Seed for randomizer. */
36: private static int counter;
37:
38: /**
39: * Generates the branch identifiers.
40: *
41: * @return a branch identifier.
42: */
43: public static String generateBranchId() {
44: String b = new Long(System.currentTimeMillis()).toString()
45: + new Random().nextLong();
46: byte bid[] = digest(b.getBytes());
47:
48: // cryptographically random string.
49: // prepend with a magic cookie to indicate we
50: // are bis09 compatible.
51: return SIPConstants.GENERAL_BRANCH_MAGIC_COOKIE
52: + Utils.toHexString(bid);
53: }
54:
55: /**
56: * Generates a call identifier for the stack.
57: * @param stackAddr current stack address
58: *
59: * @return a call id.
60: */
61: public static String generateCallIdentifier(String stackAddr) {
62: String date = (new Date()).toString()
63: + new Random(counter++).nextLong();
64: byte cidbytes[] = digest(date.getBytes());
65: String cidString = Utils.toHexString(cidbytes);
66: return cidString + Separators.AT + stackAddr;
67: }
68: }
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