2 // System.Security.Cryptography.RNGCryptoServiceProvider
5 // Mark Crichton (crichton@gimp.org)
6 // Sebastien Pouliot (sebastien@ximian.com)
9 // Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
11 // Permission is hereby granted, free of charge, to any person obtaining
12 // a copy of this software and associated documentation files (the
13 // "Software"), to deal in the Software without restriction, including
14 // without limitation the rights to use, copy, modify, merge, publish,
15 // distribute, sublicense, and/or sell copies of the Software, and to
16 // permit persons to whom the Software is furnished to do so, subject to
17 // the following conditions:
19 // The above copyright notice and this permission notice shall be
20 // included in all copies or substantial portions of the Software.
22 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
23 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
24 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
25 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
26 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
27 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
28 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
31 // "In the beginning there was Chaos,
32 // and within this Chaos was Power,
33 // Great Power without form."
34 // -- The Verrah Rubicon of Verena, Book One
36 using System.Globalization;
37 using System.Runtime.CompilerServices;
38 using System.Runtime.InteropServices;
41 namespace System.Security.Cryptography {
44 public sealed class RNGCryptoServiceProvider : RandomNumberGenerator {
45 private static object _lock;
46 private IntPtr _handle;
48 static RNGCryptoServiceProvider ()
51 _lock = new object ();
54 public RNGCryptoServiceProvider ()
56 _handle = RngInitialize (null);
60 public RNGCryptoServiceProvider (byte[] rgb)
62 _handle = RngInitialize (rgb);
66 public RNGCryptoServiceProvider (CspParameters cspParams)
68 // CSP selection isn't supported but we still return
69 // random data (no exception) for compatibility
70 _handle = RngInitialize (null);
74 public RNGCryptoServiceProvider (string str)
77 _handle = RngInitialize (null);
79 _handle = RngInitialize (Encoding.UTF8.GetBytes (str));
85 if (_handle == IntPtr.Zero) {
86 throw new CryptographicException (
87 Locale.GetText ("Couldn't access random source."));
91 [MethodImplAttribute(MethodImplOptions.InternalCall)]
92 private static extern bool RngOpen ();
94 [MethodImplAttribute(MethodImplOptions.InternalCall)]
95 private static extern IntPtr RngInitialize (byte[] seed);
97 [MethodImplAttribute(MethodImplOptions.InternalCall)]
98 private static extern IntPtr RngGetBytes (IntPtr handle, byte[] data);
100 [MethodImplAttribute(MethodImplOptions.InternalCall)]
101 private static extern void RngClose (IntPtr handle);
103 public override void GetBytes (byte[] data)
106 throw new ArgumentNullException ("data");
109 _handle = RngGetBytes (_handle, data);
111 // using a global handle for randomness
113 _handle = RngGetBytes (_handle, data);
119 public override void GetNonZeroBytes (byte[] data)
122 throw new ArgumentNullException ("data");
124 byte[] random = new byte [data.Length * 2];
126 // one pass should be enough but hey this is random ;-)
127 while (i < data.Length) {
128 _handle = RngGetBytes (_handle, random);
130 for (int j=0; j < random.Length; j++) {
131 if (i == data.Length)
134 data [i++] = random [j];
139 ~RNGCryptoServiceProvider ()
141 if (_handle != IntPtr.Zero) {
143 _handle = IntPtr.Zero;