добавляет базовую авторизацию через SQLite

Authorization.cs

@@ -0,0 +1,87 @@
+using System;
+using System.Text;
+using System.IO;
+using System.Security.Cryptography;
+using Microsoft.Data.Sqlite;
+
+namespace AwesomeEmailExtractor
+{
+    public class Authorization
+    {
+        public static User Login(string login, string password)
+        {
+            SqliteCommand command = new SqliteCommand();
+            command.Connection = Globals.db;
+            command.CommandText = "SELECT login, role_id FROM users WHERE login = @login AND password = @password";
+
+            SqliteParameter loginParam = new SqliteParameter("@login", login);
+            command.Parameters.Add(loginParam);
+
+            SqliteParameter passwordParam = new SqliteParameter("@password", EncryptPassword(password));
+            command.Parameters.Add(passwordParam);
+
+            SqliteDataReader reader = command.ExecuteReader();
+
+            while (reader.Read())
+            {
+                return new User(reader.GetString(0), (UserRoles)reader.GetInt32(1));
+            }
+
+            throw new Exception("Пользователь не найден!");
+        }
+
+        public static User Register(string login, string password)
+        {
+            SqliteCommand command = new SqliteCommand();
+            command.Connection = Globals.db;
+            command.CommandText = "INSERT INTO users (login, password, role_id) VALUES (@login, @password, 0);";
+
+            SqliteParameter loginParam = new SqliteParameter("@login", login);
+            command.Parameters.Add(loginParam);
+
+            SqliteParameter passwordParam = new SqliteParameter("@password", EncryptPassword(password));
+            command.Parameters.Add(passwordParam);
+
+            try
+            {
+                command.ExecuteNonQuery();
+            } catch (SqliteException e)
+            {
+                if (e.SqliteErrorCode == 19) {
+                    throw new Exception("Имя пользователя занятно!");
+                }
+
+                throw new Exception($"Ошибка: {e.Message}");
+            };
+
+            return new User(login, UserRoles.DEFAULT);
+        } 
+
+        public static string EncryptPassword(string password)
+        {
+            using (MD5CryptoServiceProvider md5 = new MD5CryptoServiceProvider())
+            {
+                UTF8Encoding utf8 = new UTF8Encoding();
+                byte[] data = md5.ComputeHash(utf8.GetBytes(password));
+                return Convert.ToBase64String(data);
+            }
+        }
+    }
+
+    public enum UserRoles
+    {
+        DEFAULT,
+        ADMIN
+    }
+    public class User
+    {
+        public string Login { get; set; }
+        public UserRoles Role { get; }
+
+        public User(string login, UserRoles role)
+        {
+            Login = login;
+            Role = role;
+        }
+    }
+}

AwesomeEmailExtractor.csproj

@@ -12,6 +12,8 @@
     <FileAlignment>512</FileAlignment>
     <AutoGenerateBindingRedirects>true</AutoGenerateBindingRedirects>
     <Deterministic>true</Deterministic>
+    <NuGetPackageImportStamp>
+    </NuGetPackageImportStamp>
   </PropertyGroup>
   <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
     <PlatformTarget>AnyCPU</PlatformTarget>
@@ -33,8 +35,36 @@
     <WarningLevel>4</WarningLevel>
   </PropertyGroup>
   <ItemGroup>
+    <Reference Include="Microsoft.Data.Sqlite, Version=5.0.3.0, Culture=neutral, PublicKeyToken=adb9793829ddae60, processorArchitecture=MSIL">
+      <HintPath>packages\Microsoft.Data.Sqlite.Core.5.0.3\lib\netstandard2.0\Microsoft.Data.Sqlite.dll</HintPath>
+    </Reference>
+    <Reference Include="SQLitePCLRaw.batteries_v2, Version=2.0.4.976, Culture=neutral, PublicKeyToken=8226ea5df37bcae9, processorArchitecture=MSIL">
+      <HintPath>packages\SQLitePCLRaw.bundle_e_sqlite3.2.0.4\lib\net461\SQLitePCLRaw.batteries_v2.dll</HintPath>
+    </Reference>
+    <Reference Include="SQLitePCLRaw.core, Version=2.0.4.976, Culture=neutral, PublicKeyToken=1488e028ca7ab535, processorArchitecture=MSIL">
+      <HintPath>packages\SQLitePCLRaw.core.2.0.4\lib\netstandard2.0\SQLitePCLRaw.core.dll</HintPath>
+    </Reference>
+    <Reference Include="SQLitePCLRaw.nativelibrary, Version=2.0.4.976, Culture=neutral, PublicKeyToken=502ed628492ab262, processorArchitecture=MSIL">
+      <HintPath>packages\SQLitePCLRaw.bundle_e_sqlite3.2.0.4\lib\net461\SQLitePCLRaw.nativelibrary.dll</HintPath>
+    </Reference>
+    <Reference Include="SQLitePCLRaw.provider.dynamic_cdecl, Version=2.0.4.976, Culture=neutral, PublicKeyToken=b68184102cba0b3b, processorArchitecture=MSIL">
+      <HintPath>packages\SQLitePCLRaw.provider.dynamic_cdecl.2.0.4\lib\netstandard2.0\SQLitePCLRaw.provider.dynamic_cdecl.dll</HintPath>
+    </Reference>
     <Reference Include="System" />
+    <Reference Include="System.Buffers, Version=4.0.2.0, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Buffers.4.4.0\lib\netstandard2.0\System.Buffers.dll</HintPath>
+    </Reference>
     <Reference Include="System.Core" />
+    <Reference Include="System.Memory, Version=4.0.1.1, Culture=neutral, PublicKeyToken=cc7b13ffcd2ddd51, processorArchitecture=MSIL">
+      <HintPath>packages\System.Memory.4.5.3\lib\netstandard2.0\System.Memory.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Numerics" />
+    <Reference Include="System.Numerics.Vectors, Version=4.1.3.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>packages\System.Numerics.Vectors.4.4.0\lib\net46\System.Numerics.Vectors.dll</HintPath>
+    </Reference>
+    <Reference Include="System.Runtime.CompilerServices.Unsafe, Version=4.0.4.1, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a, processorArchitecture=MSIL">
+      <HintPath>packages\System.Runtime.CompilerServices.Unsafe.4.5.2\lib\netstandard2.0\System.Runtime.CompilerServices.Unsafe.dll</HintPath>
+    </Reference>
     <Reference Include="System.Xml.Linq" />
     <Reference Include="System.Data.DataSetExtensions" />
     <Reference Include="Microsoft.CSharp" />
@@ -46,7 +76,9 @@
     <Reference Include="System.Xml" />
   </ItemGroup>
   <ItemGroup>
+    <Compile Include="Authorization.cs" />
     <Compile Include="ExtactEmailsAlgorithm.cs" />
+    <Compile Include="Globals.cs" />
     <Compile Include="MainForm.cs">
       <SubType>Form</SubType>
     </Compile>
@@ -67,6 +99,7 @@
       <AutoGen>True</AutoGen>
       <DependentUpon>Resources.resx</DependentUpon>
     </Compile>
+    <None Include="packages.config" />
     <None Include="Properties\Settings.settings">
       <Generator>SettingsSingleFileGenerator</Generator>
       <LastGenOutput>Settings.Designer.cs</LastGenOutput>
@@ -81,4 +114,11 @@
     <None Include="App.config" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <Import Project="packages\SQLitePCLRaw.lib.e_sqlite3.2.0.4\build\net461\SQLitePCLRaw.lib.e_sqlite3.targets" Condition="Exists('packages\SQLitePCLRaw.lib.e_sqlite3.2.0.4\build\net461\SQLitePCLRaw.lib.e_sqlite3.targets')" />
+  <Target Name="EnsureNuGetPackageBuildImports" BeforeTargets="PrepareForBuild">
+    <PropertyGroup>
+      <ErrorText>Данный проект ссылается на пакеты NuGet, отсутствующие на этом компьютере. Используйте восстановление пакетов NuGet, чтобы скачать их.  Дополнительную информацию см. по адресу: http://go.microsoft.com/fwlink/?LinkID=322105. Отсутствует следующий файл: {0}.</ErrorText>
+    </PropertyGroup>
+    <Error Condition="!Exists('packages\SQLitePCLRaw.lib.e_sqlite3.2.0.4\build\net461\SQLitePCLRaw.lib.e_sqlite3.targets')" Text="$([System.String]::Format('$(ErrorText)', 'packages\SQLitePCLRaw.lib.e_sqlite3.2.0.4\build\net461\SQLitePCLRaw.lib.e_sqlite3.targets'))" />
+  </Target>
 </Project>

Globals.cs

@@ -0,0 +1,68 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using System.IO;
+using Microsoft.Data.Sqlite;
+
+
+namespace AwesomeEmailExtractor
+{
+    internal class Globals
+    {
+        // Getter and setter for SQLite database connection
+        public static SqliteConnection db { get; set; }
+
+        public static string getAppDirectory()
+        {
+            return Path.Combine(
+                Environment.GetFolderPath(
+                    Environment.SpecialFolder.ApplicationData
+                ),
+                 "AwesomeEmailExtractor"
+            );
+        }
+
+        public static string getAppDatabase()
+        {
+            return Path.Combine(
+                getAppDirectory(),
+                "database.db"
+            );
+        }
+
+            
+
+        public static void CreateTables()
+        {
+            SqliteCommand command = new SqliteCommand();
+            command.Connection = db;
+            
+            // Создать таблицу для хранения ролей
+            command.CommandText = "CREATE TABLE IF NOT EXISTS roles (id INTEGER PRIMARY KEY, name TEXT NOT NULL);";
+            command.ExecuteNonQuery();
+
+            // Добавить роли
+            command.CommandText = "INSERT OR IGNORE INTO roles (id, name) VALUES (0, 'DEFAULT'), (1, 'ADMIN');";
+            command.ExecuteNonQuery();
+
+            // Создать таблицу для хранения пользователей
+            command.CommandText = "CREATE TABLE IF NOT EXISTS users (id INTEGER PRIMARY KEY AUTOINCREMENT, login TEXT NOT NULL UNIQUE, password TEXT NOT NULL, role_id INTEGER NOT NULL, FOREIGN KEY(role_id) REFERENCES roles(id));";
+            command.ExecuteNonQuery();
+
+            // Если таблица пуста - добавить пользователя по умолчанию
+            command.CommandText = "SELECT COUNT(*) FROM users";
+
+            if (Convert.ToInt32(command.ExecuteScalar()) == 0)
+            {
+                command.CommandText = "INSERT INTO users (login, password, role_id) VALUES ('admin', @password, 1);";
+
+                SqliteParameter passwordParam = new SqliteParameter("@password", Authorization.EncryptPassword("admin"));
+                command.Parameters.Add(passwordParam);                
+                command.ExecuteNonQuery();
+                command.Parameters.Clear();
+            }
+        }
+    }
+}

Program.cs

@@ -3,6 +3,8 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using System.Windows.Forms;
+using System.IO;
+using Microsoft.Data.Sqlite;
 
 namespace AwesomeEmailExtractor
 {
@@ -14,9 +16,31 @@ namespace AwesomeEmailExtractor
         [STAThread]
         static void Main()
         {
+            preMain();
+            
             Application.EnableVisualStyles();
             Application.SetCompatibleTextRenderingDefault(false);
             Application.Run(new MainForm());
+
+            postMain();
+        }
+
+        static void preMain()
+        {
+            if (!Directory.Exists(Globals.getAppDirectory()))
+            {
+                Directory.CreateDirectory(Globals.getAppDirectory());
+            }
+
+            Globals.db = new SqliteConnection("Data Source=" + Globals.getAppDatabase());
+            Globals.db.Open();
+
+            Globals.CreateTables();
+        }
+
+        static void postMain()
+        {
+            Globals.db.Close();
         }
     }
 }

packages.config

@@ -0,0 +1,13 @@
+<?xml version="1.0" encoding="utf-8"?>
+<packages>
+  <package id="Microsoft.Data.Sqlite" version="5.0.3" targetFramework="net472" />
+  <package id="Microsoft.Data.Sqlite.Core" version="5.0.3" targetFramework="net472" />
+  <package id="SQLitePCLRaw.bundle_e_sqlite3" version="2.0.4" targetFramework="net472" />
+  <package id="SQLitePCLRaw.core" version="2.0.4" targetFramework="net472" />
+  <package id="SQLitePCLRaw.lib.e_sqlite3" version="2.0.4" targetFramework="net472" />
+  <package id="SQLitePCLRaw.provider.dynamic_cdecl" version="2.0.4" targetFramework="net472" />
+  <package id="System.Buffers" version="4.4.0" targetFramework="net472" />
+  <package id="System.Memory" version="4.5.3" targetFramework="net472" />
+  <package id="System.Numerics.Vectors" version="4.4.0" targetFramework="net472" />
+  <package id="System.Runtime.CompilerServices.Unsafe" version="4.5.2" targetFramework="net472" />
+</packages>