login

Imports MySql.Data.MySqlClient
Imports System.Security.Cryptography
Imports System.Text
Public Class FrmLogin
    Public connDB As New MySqlConnection
    Public comDB As New MySqlCommand
    Public rdDB As MySqlDataReader
    Public myError As MySqlError
    Public SQL As String
    Sub conectDB()
        Dim strServer As String = "localhost"
        Dim strDbase As String = "testdb"
        Dim strUser As String = "root"
        Dim strPass As String = ""

        If connDB.State <> ConnectionState.Open Then connDB.ConnectionString = "server=" & strServer.Trim & ";database=" & strDbase.Trim & ";user=" & strUser.Trim & ";password=" & strPass
        If connDB.State <> ConnectionState.Open Then connDB.Open()
    End Sub
    Sub closeDB()
        If connDB.State <> ConnectionState.Closed Then connDB.Close()
    End Sub
    Sub initCMD()
        With comDB
            .Connection = connDB
            .CommandType = CommandType.Text
            .CommandTimeout = 280000
        End With
    End Sub

    Function getMD5Hash(ByVal strToHash As String) As String
        Dim md5Obj As New MD5CryptoServiceProvider()
        Dim bytesToHash() As Byte = System.Text.Encoding.ASCII.GetBytes(strToHash)
        bytesToHash = md5Obj.ComputeHash(bytesToHash)
        Dim strResult As String = ""
        Dim b As Byte
        For Each b In bytesToHash
            strResult += b.ToString("x2")
        Next
        Return strResult
    End Function

    Private Sub FrmLogin_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        txtPassword.Text = ""
        txtUsername.Text = ""
        txtUsername.Select()
    End Sub
    Private Function ValidasiEntry() As Boolean
        If Me.txtUsername.Text.Trim = "" Or
            Me.txtPassword.Text.Trim = "" Then
            MsgBox("Username & Password Tidak Boleh Kosong!", MsgBoxStyle.Exclamation, "Error")
            Return True
        End If
    End Function
    Private Sub CekUser()
        Try
            SQL = "SELECT * from users " &
                 "WHERE status = '1' " &
                 "AND username ='" & Me.txtUsername.Text & "' " &
                 "AND password ='" & getMD5Hash(txtPassword.Text) & "'"

            With comDB
                .CommandText = SQL
                .ExecuteNonQuery()
            End With
            rdDB = comDB.ExecuteReader
            rdDB.Read()
            If rdDB.HasRows = True Then
                Me.Hide()
                Form1.Show()
            Else
                MsgBox("Username and or Password not found!", MsgBoxStyle.Exclamation, "Information")
                txtUsername.Text = ""
                txtPassword.Text = ""
                txtUsername.Select()
            End If
            rdDB.Close()
        Catch ex As Exception
            MsgBox(ex.ToString)
        End Try
    End Sub
    Private Sub LoadData(ByVal sender As Object, ByVal e As KeyEventArgs) Handles txtUsername.KeyDown, txtPassword.KeyDown
        If e.KeyCode = Keys.Enter Then
            ProcessTabKey(True)
        End If
    End Sub
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        If ValidasiEntry() = True Then
            txtUsername.Select()
            Exit Sub
        End If

        Call conectDB()
        Call initCMD()
        Call CekUser()
    End Sub

    Private Sub Button2_Click(sender As Object, e As EventArgs) Handles Button2.Click
        Me.Close()
    End Sub
End Class