1 files changed, 123 insertions, 0 deletions
diff --git a/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/util/EC5Util.java b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/util/EC5Util.java
new file mode 100644
index 000000000..b6fc1ee35
--- /dev/null
+++ b/libraries/spongycastle/prov/src/main/java/org/spongycastle/jcajce/provider/asymmetric/util/EC5Util.java
@@ -0,0 +1,123 @@
+package org.spongycastle.jcajce.provider.asymmetric.util;
+
+import java.math.BigInteger;
+import java.security.spec.ECField;
+import java.security.spec.ECFieldF2m;
+import java.security.spec.ECFieldFp;
+import java.security.spec.ECParameterSpec;
+import java.security.spec.ECPoint;
+import java.security.spec.EllipticCurve;
+
+import org.spongycastle.jce.spec.ECNamedCurveParameterSpec;
+import org.spongycastle.jce.spec.ECNamedCurveSpec;
+import org.spongycastle.math.ec.ECCurve;
+
+public class EC5Util
+{
+    public static EllipticCurve convertCurve(
+        ECCurve curve, 
+        byte[]  seed)
+    {
+        // TODO: the Sun EC implementation doesn't currently handle the seed properly
+        // so at the moment it's set to null. Should probably look at making this configurable
+        if (curve instanceof ECCurve.Fp)
+        {
+            return new EllipticCurve(new ECFieldFp(((ECCurve.Fp)curve).getQ()), curve.getA().toBigInteger(), curve.getB().toBigInteger(), null);
+        }
+        else
+        {
+            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(), null);
+            }
+            else
+            {
+                ks = new int[] { curveF2m.getK3(), curveF2m.getK2(), curveF2m.getK1() };
+                
+                return new EllipticCurve(new ECFieldF2m(curveF2m.getM(), ks), curve.getA().toBigInteger(), curve.getB().toBigInteger(), null);
+            } 
+        }
+    }
+
+    public static ECCurve convertCurve(
+        EllipticCurve ec)
+    {
+        ECField field = ec.getField();
+        BigInteger a = ec.getA();
+        BigInteger b = ec.getB();
+
+        if (field instanceof ECFieldFp)
+        {
+            return new ECCurve.Fp(((ECFieldFp)field).getP(), a, b);
+        }
+        else
+        {
+            ECFieldF2m fieldF2m = (ECFieldF2m)field;
+            int m = fieldF2m.getM();
+            int ks[] = ECUtil.convertMidTerms(fieldF2m.getMidTermsOfReductionPolynomial());
+            return new ECCurve.F2m(m, ks[0], ks[1], ks[2], a, b); 
+        }
+    }
+
+    public static ECParameterSpec convertSpec(
+        EllipticCurve ellipticCurve,
+        org.spongycastle.jce.spec.ECParameterSpec spec)
+    {
+        if (spec instanceof ECNamedCurveParameterSpec)
+        {
+            return new ECNamedCurveSpec(
+                ((ECNamedCurveParameterSpec)spec).getName(),
+                ellipticCurve,
+                new ECPoint(
+                    spec.getG().getAffineXCoord().toBigInteger(),
+                    spec.getG().getAffineYCoord().toBigInteger()),
+                spec.getN(),
+                spec.getH());
+        }
+        else
+        {
+            return new ECParameterSpec(
+                ellipticCurve,
+                new ECPoint(
+                    spec.getG().getAffineXCoord().toBigInteger(),
+                    spec.getG().getAffineYCoord().toBigInteger()),
+                spec.getN(),
+                spec.getH().intValue());
+        }
+    }
+
+    public static org.spongycastle.jce.spec.ECParameterSpec convertSpec(
+        ECParameterSpec ecSpec,
+        boolean withCompression)
+    {
+        ECCurve curve = convertCurve(ecSpec.getCurve());
+
+        return new org.spongycastle.jce.spec.ECParameterSpec(
+            curve,
+            convertPoint(curve, ecSpec.getGenerator(), withCompression),
+            ecSpec.getOrder(),
+            BigInteger.valueOf(ecSpec.getCofactor()),
+            ecSpec.getCurve().getSeed());
+    }
+
+    public static org.spongycastle.math.ec.ECPoint convertPoint(
+        ECParameterSpec ecSpec,
+        ECPoint point,
+        boolean withCompression)
+    {
+        return convertPoint(convertCurve(ecSpec.getCurve()), point, withCompression);
+    }
+
+    public static org.spongycastle.math.ec.ECPoint convertPoint(
+        ECCurve curve,
+        ECPoint point,
+        boolean withCompression)
+    {
+        return curve.createPoint(point.getAffineX(), point.getAffineY(), withCompression);
+    }
+}