2 // System.Web.SessionState.SessionId
5 // Jackson Harper (jackson@ximian.com)
7 // Copyright (C) 2003,2006 Novell, Inc (http://www.novell.com)
9 // Permission is hereby granted, free of charge, to any person obtaining
10 // a copy of this software and associated documentation files (the
11 // "Software"), to deal in the Software without restriction, including
12 // without limitation the rights to use, copy, modify, merge, publish,
13 // distribute, sublicense, and/or sell copies of the Software, and to
14 // permit persons to whom the Software is furnished to do so, subject to
15 // the following conditions:
17 // The above copyright notice and this permission notice shall be
18 // included in all copies or substantial portions of the Software.
20 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
21 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
22 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
23 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
24 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
25 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
26 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
30 using System.Security.Cryptography;
32 namespace System.Web.SessionState {
34 internal class SessionId {
36 private static char [] allowed = { '0', '1', '2', '3', '4', '5',
37 '6', '7', '8', '9', 'A', 'B',
40 internal const int IdLength = 24;
41 private const int half_len = IdLength / 2;
43 internal static string Create (RandomNumberGenerator rng)
46 throw new ArgumentNullException ("rng");
48 byte[] key = new byte [half_len];
56 internal static string Encode (byte[] key)
59 throw new ArgumentNullException ("key");
60 if (key.Length != half_len)
61 throw new ArgumentException (String.Format ("key must be {0} bytes long.", half_len));
63 // Just a standard hex conversion
64 char[] res = new char [IdLength];
65 for (int i=0; i < half_len; i++) {
67 res [i * 2] = allowed [b >> 4];
68 res [(i * 2) + 1] = allowed [b & 0xF];
70 return new String (res);
73 internal static string Lookup (HttpRequest request, bool cookieless)
76 return (string) request.Headers [SessionStateModule.HeaderName];
78 HttpCookie cookie = request.Cookies [SessionStateModule.CookieName];