1 files changed, 92 insertions, 0 deletions
diff --git a/crypto/src/asn1/x509/RSAPublicKeyStructure.cs b/crypto/src/asn1/x509/RSAPublicKeyStructure.cs
new file mode 100644
index 000000000..bdcba783e
--- /dev/null
+++ b/crypto/src/asn1/x509/RSAPublicKeyStructure.cs
@@ -0,0 +1,92 @@
+using Org.BouncyCastle.Asn1;
+using Org.BouncyCastle.Math;
+
+using System;
+using System.Collections;
+
+namespace Org.BouncyCastle.Asn1.X509
+{
+    public class RsaPublicKeyStructure
+        : Asn1Encodable
+    {
+        private BigInteger modulus;
+        private BigInteger publicExponent;
+
+		public static RsaPublicKeyStructure GetInstance(
+            Asn1TaggedObject	obj,
+            bool				explicitly)
+        {
+            return GetInstance(Asn1Sequence.GetInstance(obj, explicitly));
+        }
+
+		public static RsaPublicKeyStructure GetInstance(
+            object obj)
+        {
+            if (obj == null || obj is RsaPublicKeyStructure)
+            {
+                return (RsaPublicKeyStructure) obj;
+            }
+
+			if (obj is Asn1Sequence)
+            {
+                return new RsaPublicKeyStructure((Asn1Sequence) obj);
+            }
+
+			throw new ArgumentException("Invalid RsaPublicKeyStructure: " + obj.GetType().Name);
+        }
+
+		public RsaPublicKeyStructure(
+            BigInteger	modulus,
+            BigInteger	publicExponent)
+        {
+			if (modulus == null)
+				throw new ArgumentNullException("modulus");
+			if (publicExponent == null)
+				throw new ArgumentNullException("publicExponent");
+			if (modulus.SignValue <= 0)
+				throw new ArgumentException("Not a valid RSA modulus", "modulus");
+			if (publicExponent.SignValue <= 0)
+				throw new ArgumentException("Not a valid RSA public exponent", "publicExponent");
+
+            this.modulus = modulus;
+            this.publicExponent = publicExponent;
+        }
+
+		private RsaPublicKeyStructure(
+            Asn1Sequence seq)
+        {
+			if (seq.Count != 2)
+				throw new ArgumentException("Bad sequence size: " + seq.Count);
+
+			// Note: we are accepting technically incorrect (i.e. negative) values here
+			modulus = DerInteger.GetInstance(seq[0]).PositiveValue;
+			publicExponent = DerInteger.GetInstance(seq[1]).PositiveValue;
+		}
+
+		public BigInteger Modulus
+        {
+            get { return modulus; }
+        }
+
+		public BigInteger PublicExponent
+        {
+            get { return publicExponent; }
+        }
+
+		/**
+         * This outputs the key in Pkcs1v2 format.
+         * <pre>
+         *      RSAPublicKey ::= Sequence {
+         *                          modulus Integer, -- n
+         *                          publicExponent Integer, -- e
+         *                      }
+         * </pre>
+         */
+        public override Asn1Object ToAsn1Object()
+        {
+			return new DerSequence(
+				new DerInteger(Modulus),
+				new DerInteger(PublicExponent));
+        }
+    }
+}