chore: extract SessionKey model

Author: twsc-james

EccSDK/SessionKeyGenerator.cs

@@ -1,11 +1,15 @@
+using EccSDK.models;
 using Org.BouncyCastle.Math;
 
 namespace EccSDK;
 
 public class SessionKeyGenerator
 {
-    public static BigInteger GenerateSessionKey()
+    public static SessionKey GenerateSessionKey()
     {
-        return new BigInteger(256, new Random());
+        return new SessionKey()
+        {
+            Key =  new BigInteger(256, new Random())
+        };
     }
 }

EccSDK/models/SessionKey.cs

@@ -0,0 +1,8 @@
+using Org.BouncyCastle.Math;
+
+namespace EccSDK.models;
+
+public class SessionKey
+{
+    public BigInteger Key { get; set; }
+}