Password Encyption and Decryption

Imports System
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Imports System.Data
Imports System.Data.SqlClient

Partial Class _Default
Inherits System.Web.UI.Page
Private key() As Byte = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24}
Private iv() As Byte = {65, 110, 68, 26, 69, 178, 200, 219}

Dim CCNumber() As Byte
Dim DCNumber As String
Dim strConn As String
Dim Conn As SqlConnection
Dim strSQL As String


Public Function Encrypt(ByVal plainText As String) As Byte()
Dim utf8encoder As UTF8Encoding = New UTF8Encoding()
Dim inputInBytes() As Byte = utf8encoder.GetBytes(plainText)

Dim tdesProvider As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()

Dim cryptoTransform As ICryptoTransform = tdesProvider.CreateEncryptor(Me.key, Me.iv)

Dim encryptedStream As MemoryStream = New MemoryStream()
Dim cryptStream As CryptoStream = New CryptoStream(encryptedStream, cryptoTransform, CryptoStreamMode.Write)

cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
cryptStream.FlushFinalBlock()
encryptedStream.Position = 0

Dim result(encryptedStream.Length - 1) As Byte
encryptedStream.Read(result, 0, encryptedStream.Length)
cryptStream.Close()
Return result
End Function

Public Function Decrypt(ByVal inputInBytes() As Byte) As String
Dim utf8encoder As UTF8Encoding = New UTF8Encoding()
Dim tdesProvider As TripleDESCryptoServiceProvider = New TripleDESCryptoServiceProvider()

Dim cryptoTransform As ICryptoTransform = tdesProvider.CreateDecryptor(Me.key, Me.iv)

Dim decryptedStream As MemoryStream = New MemoryStream()
Dim cryptStream As CryptoStream = New CryptoStream(decryptedStream, cryptoTransform, CryptoStreamMode.Write)
cryptStream.Write(inputInBytes, 0, inputInBytes.Length)
cryptStream.FlushFinalBlock()
decryptedStream.Position = 0

Dim result(decryptedStream.Length - 1) As Byte
decryptedStream.Read(result, 0, decryptedStream.Length)
cryptStream.Close()
Dim myutf As UTF8Encoding = New UTF8Encoding()
Return myutf.GetString(result)
End Function

Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click
CCNumber = Encrypt(Me.TextBox1.Text)
OpenConnection()
Dim cmd As New SqlCommand("INSERT INTO MYLOGIN values (@UserID, @Password)", Conn)
cmd.CommandType = CommandType.Text
cmd.Parameters.Add("@UserID", SqlDbType.VarChar).Value = "demo"
cmd.Parameters.Add("@Password", SqlDbType.VarBinary).Value = CCNumber
cmd.ExecuteNonQuery()
CloseConnection()
Response.Write("")
Me.TextBox1.Text = ""
End Sub

Private Sub OpenConnection()
strConn = System.Configuration.ConfigurationManager.AppSettings("MyDBConnection")
Conn = New SqlConnection(strConn)
Conn.Open()
End Sub

Private Sub CloseConnection()
If Conn.State = ConnectionState.Open Then Conn.Close()
End Sub


Protected Sub Button2_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button2.Click
OpenConnection()
Dim cmd As SqlCommand = New SqlCommand("SELECT * from MyLogin", Conn)
Dim DA As SqlDataAdapter = New SqlDataAdapter()
DA.SelectCommand = cmd
Dim DS As DataSet = New DataSet()
DA.Fill(DS, "MyLogin")
GridView1.DataSource = DS
GridView1.DataBind()
Conn.Close()

For Each dr In DS.Tables("MyLogin").Rows
DCNumber = Decrypt(dr.Item("Password"))
Response.Write(dr.item("Userid") & " " & DCNumber & "
")
Next
End Sub

End Class