Initial Commit

iTechSharp/srcbc/crypto/generators/DesEdeKeyGenerator.cs

@@ -0,0 +1,66 @@
+using System;
+
+using Org.BouncyCastle.Crypto.Parameters;
+
+namespace Org.BouncyCastle.Crypto.Generators
+{
+    public class DesEdeKeyGenerator
+		: DesKeyGenerator
+    {
+		public DesEdeKeyGenerator()
+		{
+		}
+
+		internal DesEdeKeyGenerator(
+			int defaultStrength)
+			: base(defaultStrength)
+		{
+		}
+
+		/**
+        * initialise the key generator - if strength is set to zero
+        * the key Generated will be 192 bits in size, otherwise
+        * strength can be 128 or 192 (or 112 or 168 if you don't count
+        * parity bits), depending on whether you wish to do 2-key or 3-key
+        * triple DES.
+        *
+        * @param param the parameters to be used for key generation
+        */
+        protected override void engineInit(
+			KeyGenerationParameters parameters)
+        {
+            base.engineInit(parameters);
+
+			if (strength == 0 || strength == (168 / 8))
+            {
+                strength = DesEdeParameters.DesEdeKeyLength;
+            }
+            else if (strength == (112 / 8))
+            {
+                strength = 2 * DesEdeParameters.DesKeyLength;
+            }
+            else if (strength != DesEdeParameters.DesEdeKeyLength
+                && strength != (2 * DesEdeParameters.DesKeyLength))
+            {
+                throw new ArgumentException("DESede key must be "
+                    + (DesEdeParameters.DesEdeKeyLength * 8) + " or "
+                    + (2 * 8 * DesEdeParameters.DesKeyLength)
+                    + " bits long.");
+            }
+        }
+
+        protected override byte[] engineGenerateKey()
+        {
+            byte[] newKey;
+
+			do
+            {
+                newKey = random.GenerateSeed(strength);
+                DesEdeParameters.SetOddParity(newKey);
+            }
+            while (DesEdeParameters.IsWeakKey(newKey, 0, newKey.Length));
+
+            return newKey;
+        }
+    }
+}