1 files changed, 19 insertions, 19 deletions
diff --git a/bcprov/src/main/java/org/bouncycastle/jce/spec/ECNamedCurveSpec.java b/bcprov/src/main/java/org/bouncycastle/jce/spec/ECNamedCurveSpec.java
index c1b5ccc6..36aa595e 100644
--- a/bcprov/src/main/java/org/bouncycastle/jce/spec/ECNamedCurveSpec.java
+++ b/bcprov/src/main/java/org/bouncycastle/jce/spec/ECNamedCurveSpec.java
@@ -1,6 +1,7 @@
 package org.bouncycastle.jce.spec;
 
 import java.math.BigInteger;
+import java.security.spec.ECField;
 import java.security.spec.ECFieldF2m;
 import java.security.spec.ECFieldFp;
 import java.security.spec.ECPoint;
@@ -8,6 +9,10 @@ import java.security.spec.EllipticCurve;
 
 import org.bouncycastle.math.ec.ECAlgorithms;
 import org.bouncycastle.math.ec.ECCurve;
+import org.bouncycastle.math.field.FiniteField;
+import org.bouncycastle.math.field.Polynomial;
+import org.bouncycastle.math.field.PolynomialExtensionField;
+import org.bouncycastle.util.Arrays;
 
 /**
  * specification signifying that the curve parameters can also be
@@ -22,29 +27,24 @@ public class ECNamedCurveSpec
         ECCurve  curve,
         byte[]   seed)
     {
-        if (ECAlgorithms.isFpCurve(curve))
+        ECField field = convertField(curve.getField());
+        BigInteger a = curve.getA().toBigInteger(), b = curve.getB().toBigInteger();
+        return new EllipticCurve(field, a, b, seed);
+    }
+
+    private static ECField convertField(FiniteField field)
+    {
+        if (ECAlgorithms.isFpField(field))
         {
-            return new EllipticCurve(new ECFieldFp(curve.getField().getCharacteristic()), curve.getA().toBigInteger(), curve.getB().toBigInteger(), seed);
+            return new ECFieldFp(field.getCharacteristic());
         }
-        else
+        else //if (ECAlgorithms.isF2mField(curveField))
         {
-            ECCurve.F2m curveF2m = (ECCurve.F2m)curve;
-            int ks[];
-            
-            if (curveF2m.isTrinomial())
-            {
-                ks = new int[] { curveF2m.getK1() };
-                
-                return new EllipticCurve(new ECFieldF2m(curveF2m.getM(), ks), curve.getA().toBigInteger(), curve.getB().toBigInteger(), seed);
-            }
-            else
-            {
-                ks = new int[] { curveF2m.getK3(), curveF2m.getK2(), curveF2m.getK1() };
-
-                return new EllipticCurve(new ECFieldF2m(curveF2m.getM(), ks), curve.getA().toBigInteger(), curve.getB().toBigInteger(), seed);
-            } 
+            Polynomial poly = ((PolynomialExtensionField)field).getMinimalPolynomial();
+            int[] exponents = poly.getExponentsPresent();
+            int[] ks = Arrays.reverse(Arrays.copyOfRange(exponents, 1, exponents.length - 1));
+            return new ECFieldF2m(poly.getDegree(), ks);
         }
-
     }
     
     private static ECPoint convertPoint(