From 176743ab5faec2dd275b5efd3a2dd62c610f237a Mon Sep 17 00:00:00 2001
From: Oren Novotny <oren@novotny.org>
Date: Wed, 26 Feb 2014 10:08:50 -0500
Subject: Add BouncyCastle PCL files

---
 Crypto/src/crypto/CipherKeyGenerator.cs | 83 +++++++++++++++++++++++++++++++++
 1 file changed, 83 insertions(+)
 create mode 100644 Crypto/src/crypto/CipherKeyGenerator.cs

(limited to 'Crypto/src/crypto/CipherKeyGenerator.cs')

diff --git a/Crypto/src/crypto/CipherKeyGenerator.cs b/Crypto/src/crypto/CipherKeyGenerator.cs
new file mode 100644
index 000000000..5d00d34dd
--- /dev/null
+++ b/Crypto/src/crypto/CipherKeyGenerator.cs
@@ -0,0 +1,83 @@
+using System;
+
+using Org.BouncyCastle.Security;
+
+namespace Org.BouncyCastle.Crypto
+{
+	/**
+	 * The base class for symmetric, or secret, cipher key generators.
+	 */
+	public class CipherKeyGenerator
+	{
+		protected internal SecureRandom	random;
+		protected internal int			strength;
+		private bool uninitialised = true;
+		private int defaultStrength;
+
+		public CipherKeyGenerator()
+		{
+		}
+
+		internal CipherKeyGenerator(
+			int defaultStrength)
+		{
+			if (defaultStrength < 1)
+				throw new ArgumentException("strength must be a positive value", "defaultStrength");
+
+			this.defaultStrength = defaultStrength;
+		}
+
+		public int DefaultStrength
+		{
+			get { return defaultStrength; }
+		}
+
+		/**
+		 * initialise the key generator.
+		 *
+		 * @param param the parameters to be used for key generation
+		 */
+		public void Init(
+			KeyGenerationParameters parameters)
+		{
+			if (parameters == null)
+				throw new ArgumentNullException("parameters");
+
+			this.uninitialised = false;
+
+			engineInit(parameters);
+		}
+
+		protected virtual void engineInit(
+			KeyGenerationParameters parameters)
+		{
+			this.random = parameters.Random;
+			this.strength = (parameters.Strength + 7) / 8;
+		}
+
+		/**
+		 * Generate a secret key.
+		 *
+		 * @return a byte array containing the key value.
+		 */
+		public byte[] GenerateKey()
+		{
+			if (uninitialised)
+			{
+				if (defaultStrength < 1)
+					throw new InvalidOperationException("Generator has not been initialised");
+
+				uninitialised = false;
+
+				engineInit(new KeyGenerationParameters(new SecureRandom(), defaultStrength));
+			}
+
+			return engineGenerateKey();
+		}
+
+		protected virtual byte[] engineGenerateKey()
+		{
+			return random.GenerateSeed(strength);
+		}
+	}
+}
-- 
cgit 1.5.1