1 files changed, 37 insertions, 0 deletions
diff --git a/src/cz/crcs/ectester/common/util/ECUtil.java b/src/cz/crcs/ectester/common/util/ECUtil.java
new file mode 100644
index 0000000..713effe
--- /dev/null
+++ b/src/cz/crcs/ectester/common/util/ECUtil.java
@@ -0,0 +1,37 @@
+package cz.crcs.ectester.common.util;
+
+import java.math.BigInteger;
+import java.security.spec.ECPoint;
+
+/**
+ * @author Jan Jancar johny@neuromancer.sk
+ */
+public class ECUtil {
+    public static byte[] toX962Compressed(ECPoint point) {
+        if (point.equals(ECPoint.POINT_INFINITY)) {
+            return new byte[]{0};
+        }
+        byte[] x = point.getAffineX().toByteArray();
+        byte marker = (byte) (0x02 | point.getAffineY().mod(BigInteger.valueOf(2)).byteValue());
+        return ByteUtil.concatenate(new byte[]{marker}, x);
+    }
+
+    public static byte[] toX962Uncompressed(ECPoint point) {
+        if (point.equals(ECPoint.POINT_INFINITY)) {
+            return new byte[]{0};
+        }
+        byte[] x = point.getAffineX().toByteArray();
+        byte[] y = point.getAffineY().toByteArray();
+        return ByteUtil.concatenate(new byte[]{0x04}, x, y);
+    }
+
+    public static byte[] toX962Hybrid(ECPoint point) {
+        if (point.equals(ECPoint.POINT_INFINITY)) {
+            return new byte[]{0};
+        }
+        byte[] x = point.getAffineX().toByteArray();
+        byte[] y = point.getAffineY().toByteArray();
+        byte marker = (byte) (0x06 | point.getAffineY().mod(BigInteger.valueOf(2)).byteValue());
+        return ByteUtil.concatenate(new byte[]{marker}, x, y);
+    }
+}