在VB 10中創建一個區分大小寫的登錄表單

Question

我想創建一個登錄表單，其中的密碼字段是區分大小寫的例子，如果我的密碼是「PassWord」，它將只接受關鍵字「PassWord」而不接受「password」或者「密碼」等關鍵字，我希望它的字符敏感的感謝，請幫助我使用數據庫MS ACCESS感謝這裏我是一個新的編程是我的代碼

Private Sub btnLog_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnLog.Click 
    Try 
     Dim con As New OleDbConnection("Provider=Microsoft.ACE.OLEDB.12.0;Data Source=|DataDirectory|\NIASecurity.accdb") 
     Dim cmd As OleDbCommand = New OleDbCommand("SELECT [Username] FROM [Security] WHERE [Username] = @User and Password =@Pass ", con) 
     cmd.Parameters.AddWithValue("@User", txtUser.Text) 
     cmd.Parameters.AddWithValue("@Pass", txtPass.Text) 
     con.Open() 
     Dim sdr As OleDbDataReader = cmd.ExecuteReader() 
     If sdr.Read Then 
      If txtPass.Text = sdr(0) Then 
       MessageBox.Show("Welcome") 
       Dim win As New frmAdd 
       win.MdiParent = frmMDI 
       win.Show() 
       Me.Close() 
      Else 
       MsgBox("Invalid name or password!") 

      End If 
     End If 


    Catch ex As Exception 
     MessageBox.Show("Invalid name or password!") 
    End Try 
End Sub 

Answer 1

我可以說你保存數據庫的密碼，您必須保存密碼帶散列的數據Algorithm如MD5或SHA1
當用戶輸入登錄密碼時，輸入密碼的哈希串並比較t他的字符串密碼保存在數據庫

public static void HashPassword(string Password, out string Salt, out string Hash) 
    { 
     System.Security.Cryptography.SHA1Managed sha = new System.Security.Cryptography.SHA1Managed(); 
     Random rnd = new Random(); 
     byte[] s = new byte[20]; 
     rnd.NextBytes(s); 
     Salt = Convert.ToBase64String(s); 
     System.Text.UTF8Encoding u = new UTF8Encoding(); 
     byte[] pass = u.GetBytes(Password); 
     byte[] all = new byte[pass.Length + s.Length]; 
     Array.Copy(pass, all, pass.Length); 
     Array.Copy(s, 0, all, pass.Length, s.Length); 
     Byte[] H = sha.ComputeHash(all); 
     Hash = Convert.ToBase64String(H); 
    } 

    public bool IsPasswordCorrect(string Password, string Salt, string Hash) 
    { 
     System.Security.Cryptography.SHA1Managed sha = new System.Security.Cryptography.SHA1Managed(); 
     byte[] s = Convert.FromBase64String(Salt); 
     System.Text.UTF8Encoding u = new UTF8Encoding(); 
     byte[] pass = u.GetBytes(Password); 
     byte[] all = new byte[pass.Length + s.Length]; 
     Array.Copy(pass, all, pass.Length); 
     Array.Copy(s, 0, all, pass.Length, s.Length); 
     Byte[] H = sha.ComputeHash(all); 
     return (Hash == Convert.ToBase64String(H)); 
    } 

現在你必須使用HashPassword方法給哈希的鹽和保存散列和鹽，以分貝爲每一位用戶。
當想檢查密碼使用IsPasswordcorrect方法