Imported Upstream version 5.0.0.42

Former-commit-id: fd56571888259555122d8a0f58c68838229cea2b

mcs/class/corlib/CommonCrypto/RNGCryptoServiceProvider.cryptor.cs

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+//
+// RngCryptoServiceProvider.cryptor.cs: based on Mono's System.Security.Cryptography.RNGCryptoServiceProvider
+//
+// Authors:
+//	Mark Crichton (crichton@gimp.org)
+//	Sebastien Pouliot (sebastien@xamarun.com)
+//
+// (C) 2002
+// Copyright (C) 2004-2005 Novell, Inc (http://www.novell.com)
+// Copyright (C) 2012-2014 Xamarin Inc.
+//
+// Permission is hereby granted, free of charge, to any person obtaining
+// a copy of this software and associated documentation files (the
+// "Software"), to deal in the Software without restriction, including
+// without limitation the rights to use, copy, modify, merge, publish,
+// distribute, sublicense, and/or sell copies of the Software, and to
+// permit persons to whom the Software is furnished to do so, subject to
+// the following conditions:
+// 
+// The above copyright notice and this permission notice shall be
+// included in all copies or substantial portions of the Software.
+// 
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+// EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+// MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+// NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+// LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+// OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+// WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+//
+
+using Crimson.CommonCrypto;
+
+// http://developer.apple.com/library/ios/#DOCUMENTATION/Security/Reference/RandomizationReference/Reference/reference.html
+// we need to use the CommonCrypto implementation instead of the runtime-supported RNGCryptoServiceProvider
+// since we have no guarantee (on iOS) about /dev/[u]random availability or quality
+#if MONOTOUCH || XAMMAC
+namespace System.Security.Cryptography {
+	public class RNGCryptoServiceProvider : RandomNumberGenerator {
+		public RNGCryptoServiceProvider ()
+		{
+		}
+		
+		public RNGCryptoServiceProvider (byte[] rgb)
+		{
+		}
+
+		public RNGCryptoServiceProvider (CspParameters cspParams)
+		{
+		}
+
+		public RNGCryptoServiceProvider (string str) 
+		{
+		}
+
+		~RNGCryptoServiceProvider () 
+		{
+		}
+		
+		public override void GetBytes (byte[] data) 
+		{
+			if (data == null)
+				throw new ArgumentNullException ("data");
+					
+			Cryptor.GetRandom (data);
+		}
+		
+		public override void GetNonZeroBytes (byte[] data) 
+		{
+			if (data == null)
+				throw new ArgumentNullException ("data");
+
+			byte[] random = new byte [data.Length * 2];
+			int i = 0;
+			// one pass should be enough but hey this is random ;-)
+			while (i < data.Length) {
+				Cryptor.GetRandom (random);
+				for (int j=0; j < random.Length; j++) {
+					if (i == data.Length)
+						break;
+					if (random [j] != 0)
+						data [i++] = random [j];
+				}
+			}
+		}
+	}
+}
+#endif