Source code for Cryptography in VB.NET

Annael said:

REM: Wana JF I created a class in vb.net for file Encryption and decryption you can comment.

Code:

Imports System.Text
Imports System.IO
Imports System.Security.Cryptography
 
Friend Class Security
    Private dtTable As New DataTable("Security")
    Private ImageTable As New DataTable("Security")
    Private TEMPLOC As String
    Private Const Key As String = "KL)(!09#"
    Public Sub New()
        dtTable.Columns.Add("Key", GetType(Guid))
        dtTable.Columns.Add("Date", GetType(Date))
        dtTable.Columns.Add("Data", GetType(Byte()))
        ImageTable.Columns.Add("Key", GetType(Guid))
        TEMPLOC = IIf(My.Computer.FileSystem.SpecialDirectories.Temp.EndsWith("\"), My.Computer.FileSystem.SpecialDirectories.Temp, My.Computer.FileSystem.SpecialDirectories.Temp & "\")
 
    End Sub
    Public Function Encrypt(ByVal Location As String, ByVal seclocation As String) As String
        Try
            Dim gui As Guid = Guid.NewGuid
            Dim DataFile As String = Guid.NewGuid.ToString
            Dim SecurityFile As String = Guid.NewGuid.ToString
            Dim by() As Byte = IO.File.ReadAllBytes(Location)
            dtTable.Rows.Add(gui, Today, by)
            ImageTable.Rows.Add(gui)
            dtTable.WriteXml(TEMPLOC & DataFile)
            ImageTable.WriteXml(TEMPLOC & SecurityFile)
            Dim DataBy() As Byte = IO.File.ReadAllBytes(TEMPLOC & DataFile)
            Dim SecBy() As Byte = IO.File.ReadAllBytes(TEMPLOC & SecurityFile)
            My.Computer.FileSystem.DeleteFile(TEMPLOC & DataFile)
            My.Computer.FileSystem.DeleteFile(TEMPLOC & SecurityFile)
            Dim fileInfo As New IO.FileInfo(seclocation)
            Dim D As String = IIf(fileInfo.DirectoryName.EndsWith("\"), fileInfo.DirectoryName, fileInfo.DirectoryName & "\")
            Encrypt(SecBy, D & "Security.SEC")
            Encrypt(DataBy, TEMPLOC & DataFile & ".Temp")
            Return TEMPLOC & DataFile & ".Temp"
        Catch ex As Exception
            Throw ex
        End Try
 
        Return ""
    End Function
    Private Sub Encrypt(ByVal Data As Byte(), ByVal outFile As String)
        Try
            Dim DESalg As New System.Security.Cryptography.DESCryptoServiceProvider
 
            Dim objEncod As Encoding = Encoding.ASCII
            DESalg.Key = objEncod.GetBytes(Key)
            DESalg.IV = objEncod.GetBytes("11110000")
            Dim outStream As New FileStream(outFile, FileMode.Create, FileAccess.Write)
 
            Dim CryFile As New CryptoStream(outStream, DESalg.CreateEncryptor(DESalg.Key, DESalg.IV), CryptoStreamMode.Write)
            CryFile.Write(Data, 0, Data.Length)
 
            CryFile.Close()
            outStream.Close()
 
 
        Catch ex As Exception
            Throw New Exception(ex.Message)
        End Try
    End Sub
    Public Function Decrypt(ByVal Location As String) As String
        Try
            Dim fileInfo As New IO.FileInfo(Location)
            Dim Dir As String = IIf(fileInfo.DirectoryName.EndsWith("\"), fileInfo.DirectoryName, fileInfo.DirectoryName & "\") & "Security.SEC"
            If Not My.Computer.FileSystem.FileExists(Dir) Then
                Throw New Exception("Security file does not exists")
            End If
            Decrypt(Dir, Me.ImageTable)
            If ImageTable.Rows.Count > 0 Then
                If ImageTable.Rows.Count <= 3 Then
                    Decrypt(Location, Me.dtTable)
 
                    If dtTable.Rows(0)("Key") <> ImageTable.Rows(0)("Key") Then
 
                        Throw New Exception("Wrong Security file")
                    End If
 
                    Dim gui As Guid = dtTable.Rows(0)("Key")
                    ImageTable.Rows.Add(gui)
                    Dim data() As Byte = dtTable.Rows(0)("Data")
                    Dim loc As String = TEMPLOC & Guid.NewGuid.ToString & ".Temp"
                    IO.File.WriteAllBytes(loc, data)
                    My.Computer.FileSystem.DeleteFile(Dir)
                    Dim SecurityFile As String = Guid.NewGuid.ToString
                    ImageTable.WriteXml(TEMPLOC & SecurityFile)
                    Dim SecBy() As Byte = IO.File.ReadAllBytes(TEMPLOC & SecurityFile)
                    My.Computer.FileSystem.DeleteFile(TEMPLOC & SecurityFile)
                    Encrypt(SecBy, Dir)
                    Return loc
                Else
 
                    Throw New Exception("You have exceeded the maximum decryption")
                End If
 
            Else
                Throw New Exception("No Record in Security File")
            End If
        Catch ex As Exception
            Throw ex
        End Try
        Return ""
    End Function
    Private Sub Decrypt(ByVal inFile As String, ByVal dt As DataTable)
        Try
            dtTable.Rows.Clear()
            Dim DESalg As New DESCryptoServiceProvider
            Dim fs As New FileStream(inFile, FileMode.Open)
            Dim objEncod As Encoding = Encoding.ASCII
            DESalg.IV = objEncod.GetBytes("11110000")
            DESalg.Key = objEncod.GetBytes(Key)
            Dim cryp As New CryptoStream(fs, DESalg.CreateDecryptor(DESalg.Key, DESalg.IV), CryptoStreamMode.Read)
            dt.ReadXml(cryp)
 
 
            cryp.Close()
            fs.Close()
 
 
        Catch ex As Exception
            Throw New Exception(ex.Message)
        End Try
    End Sub
 
End Class

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redSilverDog said:

please tumia CODE tags ( ) kuwrap ur code

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