Initial Commit

iTechSharp/srcbc/crypto/generators/ElGamalParametersGenerator.cs

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+using System;
+
+using Org.BouncyCastle.Math;
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Crypto.Parameters;
+
+namespace Org.BouncyCastle.Crypto.Generators
+{
+    public class ElGamalParametersGenerator
+    {
+		private int				size;
+        private int				certainty;
+        private SecureRandom	random;
+
+		public void Init(
+            int				size,
+            int				certainty,
+            SecureRandom	random)
+        {
+            this.size = size;
+            this.certainty = certainty;
+            this.random = random;
+        }
+
+		/**
+         * which Generates the p and g values from the given parameters,
+         * returning the ElGamalParameters object.
+         * <p>
+         * Note: can take a while...
+		 * </p>
+         */
+        public ElGamalParameters GenerateParameters()
+        {
+			//
+			// find a safe prime p where p = 2*q + 1, where p and q are prime.
+			//
+			BigInteger[] safePrimes = DHParametersHelper.GenerateSafePrimes(size, certainty, random);
+
+			BigInteger p = safePrimes[0];
+			BigInteger q = safePrimes[1];
+			BigInteger g = DHParametersHelper.SelectGenerator(p, q, random);
+
+			return new ElGamalParameters(p, g);
+        }
+    }
+}