Port latest X9 EC stuff from Java API

1 files changed, 45 insertions, 9 deletions

diff --git a/crypto/src/asn1/x9/X9ECPoint.cs b/crypto/src/asn1/x9/X9ECPoint.cs
index 75d58cd38..7ef4f13bc 100644
--- a/crypto/src/asn1/x9/X9ECPoint.cs
+++ b/crypto/src/asn1/x9/X9ECPoint.cs
@@ -1,5 +1,7 @@
 using Org.BouncyCastle.Math.EC;
 
+using Org.BouncyCastle.Utilities;
+
 namespace Org.BouncyCastle.Asn1.X9
 {
     /**
@@ -8,24 +10,58 @@ namespace Org.BouncyCastle.Asn1.X9
     public class X9ECPoint
         : Asn1Encodable
     {
-        private readonly ECPoint p;
+        private readonly Asn1OctetString encoding;
+
+        private ECCurve c;
+        private ECPoint p;
+
+        public X9ECPoint(ECPoint p)
+            : this(p, false)
+        {
+        }
 
-        public X9ECPoint(
-            ECPoint p)
+        public X9ECPoint(ECPoint p, bool compressed)
         {
             this.p = p.Normalize();
+            this.encoding = new DerOctetString(p.GetEncoded(compressed));
+        }
+
+        public X9ECPoint(ECCurve c, byte[] encoding)
+        {
+            this.c = c;
+            this.encoding = new DerOctetString(Arrays.Clone(encoding));
         }
 
-        public X9ECPoint(
-            ECCurve			c,
-            Asn1OctetString	s)
+        public X9ECPoint(ECCurve c, Asn1OctetString s)
+            : this(c, s.GetOctets())
         {
-            this.p = c.DecodePoint(s.GetOctets());
+        }
+
+        public byte[] GetPointEncoding()
+        {
+            return Arrays.Clone(encoding.GetOctets());
         }
 
         public ECPoint Point
         {
-            get { return p; }
+            get
+            {
+                if (p == null)
+                {
+                    p = c.DecodePoint(encoding.GetOctets()).Normalize();
+                }
+
+                return p;
+            }
+        }
+
+        public bool IsPointCompressed
+        {
+            get
+            {
+                byte[] octets = encoding.GetOctets();
+                return octets != null && octets.Length > 0 && (octets[0] == 2 || octets[0] == 3);
+            }
         }
 
         /**
@@ -38,7 +74,7 @@ namespace Org.BouncyCastle.Asn1.X9
          */
         public override Asn1Object ToAsn1Object()
         {
-            return new DerOctetString(p.GetEncoded());
+            return encoding;
         }
     }
 }