11-27 SQL注入漏洞攻擊

public partial class login21 : System.Web.UI.Page

    {

        protected void Page_Load(object sender, EventArgs e)

        {

        }

        protected void Button1_Click(object sender, EventArgs e)

        {

            string constr = "data source=.;initial catalog=T_User;user id=sa;password=910809";

            //以上這種拼接sql語句的方法有sql注入的漏洞攻擊的問題 jk' or 1=1--

            //如果避免注入漏洞攻擊呢？使用參數的方法或存儲過程的方法

            using (SqlConnection con = new SqlConnection(constr))

            {

                string sql = string.Format("select count(*) from users where [email protected] and [email protected] ");

                using (SqlCommand cmd = new SqlCommand(sql, con))

                {

                    con.Open();

                    SqlParameter[] pms = new SqlParameter[]

                    {

                     new SqlParameter ("@username",txtuUserName .Text .Trim ()),

                     new SqlParameter ("@password",txtuPwd .Text .Trim ())

                    };

                    cmd.Parameters.AddRange(pms);

                    //在資料伺服器端執行sql語句前需要告訴它@username,@password是誰

                    //cmd.Parameters.AddWithValue("@username",txtuUserName .Text .Trim ());

                    //cmd.Parameters.AddWithValue("@password",txtuPwd .Text .Trim ());

                    int r = Convert.ToInt32(cmd.ExecuteScalar());

                    if (r > 0)

                    {

                        Response.Write("登陸成功");

                    }

                    else

                    {

                        Response.Write("登陸失敗");

                    }

                }

            }

        }

    }