C#开发中如何处理网络安全和身份验证问题及解决方法

using System;
using System.Security.Cryptography;
using System.Text;

namespace NetworkSecurity
{
    public class AES
    {
        public static byte[] Encrypt(string text, byte[] key, byte[] iv)
        {
            byte[] encrypted;
            
            using (AesManaged aes = new AesManaged())
            {
                aes.Key = key;
                aes.IV = iv;

                ICryptoTransfORM encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {
                            swEncrypt.Write(text);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }

            return encrypted;
        }

        public static string Decrypt(byte[] encryptedText, byte[] key, byte[] iv)
        {
            string text;

            using (AesManaged aes = new AesManaged())
            {
                aes.Key = key;
                aes.IV = iv;

                ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

                using (MemoryStream msDecrypt = new MemoryStream(encryptedText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {
                            text = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }

            return text;
        }
    }
}

using System;
using System.Data.SqlClient;

namespace NetworkSecurity
{
    public class SqlInjection
    {
        public static void ExecuteQuery(string username, string passWord)
        {
            string connectionString = "YourConnectionString";
            string sql = "SELECT * FROM Users WHERE Username = @Username AND Password = @Password";

            using (SqlConnection conn = new SqlConnection(connectionString))
            {
                using (SqlCommand cmd = new SqlCommand(sql, conn))
                {
                    cmd.Parameters.AddWithValue("@Username", username);
                    cmd.Parameters.AddWithValue("@Password", password);

                    conn.Open();
                    SqlDataReader reader = cmd.ExecuteReader();

                    // 处理查询结果
                    while (reader.Read())
                    {
                        // 输出查询结果
                    }

                    reader.Close();
                }
            }
        }
    }
}

using System;
using System.Web;

namespace NetworkSecurity
{
    public class XSS
    {
        public static string EncodeHtml(string input)
        {
            return HttpUtility.HtmlEncode(input);
        }

        public static string DecodeHtml(string input)
        {
            return HttpUtility.HtmlDecode(input);
        }
    }
}

using System;
using System.Web.Security;

namespace NetworkSecurity
{
    public class FormsAuthenticationDemo
    {
        public static void LogIn(string username, string password)
        {
            if (IsValidUser(username, password))
            {
                FormsAuthentication.SetAuthCookie(username, false);
                // 用户登录成功后的逻辑
            }
            else
            {
                // 用户登录失败后的逻辑
            }
        }

        public static void LoGout()
        {
            FormsAuthentication.SignOut();
        }

        public static bool IsLoggedIn()
        {
            return HttpContext.Current.User.Identity.IsAuthenticated;
        }

        private static bool IsValidUser(string username, string password)
        {
            // 验证用户逻辑
            return true; // or false;
        }
    }
}

using System;
using System.Web;
using dotnetOpenAuth.AspNet;
using Microsoft.AspNet.Membership.OpenAuth;

namespace NetworkSecurity
{
    public class OAuthDemo
    {
        public static void LogInWithGoogle()
        {
            HttpContext context = HttpContext.Current;
            var returnUrl = context.Request.Url.ToString();

            OpenAuth.AuthenticationClients.AddGoogle();

            context.Response.Redirect(OpenAuth.GetExternalLoginUrl(OpenAuth.LoginUrl(returnUrl)));
        }

        public static void ProcessOAuthCallback()
        {
            HttpContext context = HttpContext.Current;

            var result = OpenAuth.VerifyAuthentication(context.Request.Url.ToString());

            if (!result.IsSuccessful)
            {
                // 第三方身份验证失败的逻辑
            }
            else
            {
                // 第三方身份验证成功的逻辑
            }
        }
    }
}