C#-FTP - Connect to a server over FTPS, get a list of files in a specified directory, and rename those files

App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
    <startup>
        <!--Replace with your .NET version here-->
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.6.1" />
    </startup>
  <appSettings>
    <add key="FilePath" value="/sourcePath/"/>
    <add key="DestinationPath" value="/destinationPath/"/>
    <add key="UserName" value="user"/>
    <add key="Password" value="*****"/>
  </appSettings>
</configuration>

Program.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.IO;
using System.Net;

namespace FtpsListFiles
{
    class Program
    {
        static string UserName = ConfigurationManager.AppSettings["UserName"].ToString();
        static string Password = ConfigurationManager.AppSettings["Password"].ToString();

        static void Main(string[] args)
        {
            string filePath = ConfigurationManager.AppSettings["FilePath"].ToString();
            string[] servers = new string[] { "hostname" };

            bool ContinueProgram = true;
            List<string> fileList = new List<string>();

            foreach (var server in servers)
            {
                if (ContinueProgram)
                {
                    ContinueProgram = GetFilesList(server, filePath, fileList);
                }
            }
        }

        private static bool GetFilesList(string server, string filePath, List<string> fileList)
        {
            bool _results = true;
            string filesString = "";

            try
            {
                string ftpString = $@"ftp://{server}{filePath}";
                FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftpString);
                request.Method = WebRequestMethods.Ftp.ListDirectoryDetails;
                request.Credentials = new NetworkCredential(UserName, Password);
                request.EnableSsl = true;

                ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
                ServicePointManager.Expect100Continue = false;

                FtpWebResponse response = (FtpWebResponse)request.GetResponse();

                Stream responseStream = response.GetResponseStream();
                StreamReader reader = new StreamReader(responseStream);
                var line = reader.ReadToEnd();
                filesString = line.Replace("\r\n", "*").Replace("\n", "*").Replace("\r", "*");
                string[] arrayFileList = filesString.Split('*');
		ParseFilesList(filesList, arrayFileList);
                
                Console.WriteLine("Directory List Complete, status {0}", response.StatusDescription);
                reader.Close();
                response.Close();
		RenameFiles(server, filePath, ftpString, filesList);
            }
            catch (Exception ex)
            {
                _results = false;
            }
            return _results;
        }

	private static void ParseFilesList(List<string> filesList, string[] arrayFileList)
        {
            foreach (var file in arrayFileList)
            {
                if (!string.IsNullOrEmpty(file))
                {
                    if (file.Substring(file.LastIndexOf(" ") + 1) != "is.done")
                    {
                        if (Convert.ToDateTime(file.Substring(0, file.IndexOf("M") + 1)) > DateTime.Now.AddMonths(-2))
                        {
                            var fileName = file.Substring(file.LastIndexOf(" ") + 1);
                            filesList.Add(fileName);
                        }
                    }
                }
            }
        }

	private static void RenameFiles(string server, string filePath, string ftpString, List<string> filesList)
        {
            try
            {
                foreach (var file in filesList)
                {
                    Console.WriteLine(filePath + server);
                    var ftpFileString = $"{ftpString}{file}";
                    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(ftpFileString);
                    request.Method = WebRequestMethods.Ftp.Rename;
                    request.RenameTo = $"test-{file}";

                    request.Credentials = new NetworkCredential(UserName, Password);
                    request.EnableSsl = true;

                    ServicePointManager.ServerCertificateValidationCallback += (sender, cert, chain, sslPolicyErrors) => true;
                    ServicePointManager.Expect100Continue = false;

                    FtpWebResponse response = (FtpWebResponse)request.GetResponse();
                    response.Close();
                }
                Console.WriteLine("Success! All files were renamed");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Error! Failed to rename files {ex}");
                throw ex;
            }
        }
    }
}