From 0d3d38e77304655e00aa1451de61a6b193bc6169 Mon Sep 17 00:00:00 2001
From: Marcin Kostrzewski <komar86311@gmail.com>
Date: Wed, 28 Oct 2020 17:19:17 +0100
Subject: [PATCH] Implemented commitment creation

---
 src/main/java/Main/Commitment.java | 57 ++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)
 create mode 100644 src/main/java/Main/Commitment.java

diff --git a/src/main/java/Main/Commitment.java b/src/main/java/Main/Commitment.java
new file mode 100644
index 0000000..f97fd0d
--- /dev/null
+++ b/src/main/java/Main/Commitment.java
@@ -0,0 +1,57 @@
+package Main;
+
+import org.apache.log4j.Level;
+import org.apache.log4j.LogManager;
+import org.apache.log4j.Logger;
+
+import java.nio.charset.StandardCharsets;
+import java.security.MessageDigest;
+import java.security.NoSuchAlgorithmException;
+import java.util.Arrays;
+import java.util.Random;
+
+public class Commitment {
+    private static final Logger logger = LogManager.getLogger(App.class);
+
+    final private int randomSequenceByteCount = 128;
+
+    private String message;
+    private byte[] sequenceA;
+    private byte[] sequenceB;
+    private byte[] hash;
+
+    private byte[] generateRandomSequence(){
+        byte[] result = new byte[randomSequenceByteCount];
+        Random r = new Random();
+        r.nextBytes(result);
+        return result;
+    }
+
+    public Commitment(String message) {
+        logger.log(Level.INFO, "Creating commitment...");
+        this.message = message;
+
+        this.sequenceA = generateRandomSequence();
+        logger.log(Level.INFO, "Random sequence A is " + Arrays.toString(this.sequenceA));
+        this.sequenceB = generateRandomSequence();
+        logger.log(Level.INFO, "Random sequence B is " + Arrays.toString(this.sequenceB));
+
+        try {
+            MessageDigest digest = MessageDigest.getInstance("SHA-256");
+            digest.update(this.sequenceA);
+            digest.update(this.sequenceB);
+            digest.update(this.message.getBytes(StandardCharsets.UTF_8));
+
+            this.hash = digest.digest();
+            logger.log(Level.INFO, "Hash is " + Arrays.toString(this.hash));
+        } catch (NoSuchAlgorithmException e) {
+            e.printStackTrace();
+        }
+    }
+
+    public Commitment() {
+    }
+
+
+
+}