--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/ServerMonitor/Objects/Server.cs	Mon Dec 31 18:32:14 2018 -0500
@@ -0,0 +1,146 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Security.Cryptography;
+using System.ComponentModel;
+using Renci.SshNet;
+using System.Runtime.Serialization;
+
+namespace ServerMonitorApp
+{
+    public enum LoginType { PrivateKey = 0, Password = 1 };
+
+    public class Server
+    {
+        private string _host;
+        private int _port;
+        private string _username;
+        private LoginType _loginType;
+        private string _keyFile;
+        private SshClient _sshClient;
+        private byte[] passwordHash;
+
+        public event EventHandler CheckModified;
+
+        public readonly BindingList<Check> Checks = new BindingList<Check>();
+
+        public int Id { get; set; }
+
+        public string Name { get; set; }
+
+        public string Host
+        {
+            get { return _host; }
+            set { _host = value; InvalidateSshConnection(); }
+        }
+
+        public int Port
+        {
+            get { return _port; }
+            set { _port = value; InvalidateSshConnection(); }
+        }
+
+        public string Username
+        {
+            get { return _username; }
+            set { _username = value; InvalidateSshConnection(); }
+        }
+
+        public LoginType LoginType
+        {
+            get { return _loginType; }
+            set { _loginType = value; InvalidateSshConnection(); }
+        }
+
+        public string KeyFile
+        {
+            get { return _keyFile; }
+            set { _keyFile = value; InvalidateSshConnection(); }
+        }
+
+        public string Password
+        {
+            get {
+                return passwordHash == null ? null :
+                    Encoding.UTF8.GetString(ProtectedData.Unprotect(passwordHash, Encoding.UTF8.GetBytes("Server".Reverse().ToString()), DataProtectionScope.CurrentUser));
+            }
+            set
+            {
+                passwordHash = ProtectedData.Protect(Encoding.UTF8.GetBytes(value),
+                                 Encoding.UTF8.GetBytes("Server".Reverse().ToString()), // Minor obfuscation of additional entropy
+                                 DataProtectionScope.CurrentUser);
+            }
+        }
+
+        public bool Enabled { get; set; } = true;
+
+        public SshClient SshClient
+        {
+            get
+            {
+                if (_sshClient == null)
+                {
+                    AuthenticationMethod auth = null;
+                    if (LoginType == LoginType.Password)
+                        auth = new PasswordAuthenticationMethod(Username, Password);
+                    else
+                        new PrivateKeyAuthenticationMethod(Username, new PrivateKeyFile(KeyFile));
+                    ConnectionInfo info = new ConnectionInfo(Host, Port, Username, auth);
+                    _sshClient = new SshClient(info);
+                }
+                return _sshClient;
+            }
+        }
+
+        /*public Server() { }
+
+        public Server(Server server)
+        {
+            Name = server.Name;
+            Host = server.Host;
+            Port = server.Port;
+            Username = server.Username;
+            LoginType = server.LoginType;
+            KeyFile = server.KeyFile;
+            Enabled = server.Enabled;
+        }*/
+
+        public void DeleteCheck(Check check)
+        {
+            Checks.Remove(check);
+            check.Server = null;
+            CheckModified?.Invoke(check, new EventArgs());
+        }
+
+        public string Validate()
+        {
+            string message = string.Empty;
+            if (Name.Length == 0)
+                message += "\"Name\" must not be empty" + Environment.NewLine;
+            if (Host.Length == 0)
+                message += "\"Host\" must not be empty" + Environment.NewLine;
+            return message.Length > 0 ? message : null;
+        }
+
+        public void UpdateCheck(Check check)
+        {
+            Check oldCheck = Checks.FirstOrDefault(c => c.Id == check.Id);
+            if (!ReferenceEquals(check, oldCheck))
+            {
+                int index = Checks.IndexOf(oldCheck);
+                if (index == -1)
+                    Checks.Add(check);
+                else
+                    Checks[index] = check;
+            }
+            CheckModified?.Invoke(check, new EventArgs());
+        }
+
+        private void InvalidateSshConnection()
+        {
+            _sshClient?.Dispose();
+            _sshClient = null;
+        }
+    }
+}