Merge pull request #39 from crocs-muni/epare

Add epare artifact

2 files changed, 31 insertions, 0 deletions

diff --git a/common/src/main/java/cz/crcs/ectester/common/ec/EC_Params.java b/common/src/main/java/cz/crcs/ectester/common/ec/EC_Params.java
index 8d15437..24e9d56 100644
--- a/common/src/main/java/cz/crcs/ectester/common/ec/EC_Params.java
+++ b/common/src/main/java/cz/crcs/ectester/common/ec/EC_Params.java
@@ -5,6 +5,7 @@ import cz.crcs.ectester.common.util.CardUtil;
 
 import java.io.ByteArrayOutputStream;
 import java.util.ArrayList;
+import java.util.Arrays;
 import java.util.List;
 
 /**
@@ -265,6 +266,29 @@ public class EC_Params extends EC_Data {
         return p;
     }
 
+    public static EC_Params merge(EC_Params p1, EC_Params p2) {
+        if ((p1.params & p2.params) != 0) {
+            throw new IllegalArgumentException("Cannot merge EC_Params with overlapping parameters.");
+        }
+        short params = (short) (p1.params | p2.params);
+        List<byte[]> dataList = new ArrayList<>();
+        short paramMask = EC_Consts.PARAMETER_FP;
+        while (paramMask <= EC_Consts.PARAMETER_S) {
+            byte[][] paramData;
+            if ((p1.params & paramMask) != 0) {
+                paramData = p1.getParam(paramMask);
+            } else if ((p2.params & paramMask) != 0) {
+                paramData = p2.getParam(paramMask);
+            } else {
+                throw new IllegalArgumentException("Cannot merge EC_Params with overlapping parameters.");
+            }
+            dataList.addAll(Arrays.asList(paramData));
+            paramMask = (short) (paramMask << 1);
+        }
+
+        return new EC_Params(params, dataList.toArray(new byte[dataList.size()][]));
+    }
+
     @Override
     public String[] expand() {
         List<String> out = new ArrayList<>();
diff --git a/common/src/main/java/cz/crcs/ectester/common/util/ECUtil.java b/common/src/main/java/cz/crcs/ectester/common/util/ECUtil.java
index 6eb0b1a..677075b 100644
--- a/common/src/main/java/cz/crcs/ectester/common/util/ECUtil.java
+++ b/common/src/main/java/cz/crcs/ectester/common/util/ECUtil.java
@@ -71,6 +71,13 @@ public class ECUtil {
         return toX962Compressed(point, spec.getCurve().getField().getFieldSize());
     }
 
+    public static byte[] toX962Uncompressed(byte[][] point) {
+        if (point.length != 2) {
+            return null;
+        }
+        return ByteUtil.concatenate(new byte[]{(byte) (0x04)}, point[0], point[1]);
+    }
+
     public static byte[] toX962Uncompressed(ECPoint point, int bits) {
         if (point.equals(ECPoint.POINT_INFINITY)) {
             return new byte[]{0};