Encrypting a file
Imports System.Security.Cryptography
Module MainModule
Public Function GenerateKey() As Byte()
Dim objDES As New System.Security.Cryptography.DESCryptoServiceProvider()
objDES.GenerateKey()
Return objDES.Key
End Function
Public Function GenerateIV() As Byte()
Dim objDES As New System.Security.Cryptography.DESCryptoServiceProvider()
objDES.GenerateIV()
Return objDES.IV
End Function
Public Sub SaveEncryptedFile(ByVal Key() As Byte, ByVal IV() As Byte, ByVal Data As String, ByVal Filename As String)
Dim objFileStream As New System.IO.FileStream(Filename, System.IO.FileMode.Create, System.IO.FileAccess.Write)
Dim bytInput As Byte() = New System.Text.UnicodeEncoding().GetBytes(Data)
Dim objDES As New DESCryptoServiceProvider()
objDES.Key = Key
objDES.IV = IV
Dim objDESEncrypt As ICryptoTransform = objDES.CreateEncryptor()
Dim objCryptStream As New CryptoStream(objFileStream, objDESEncrypt, CryptoStreamMode.Write)
objCryptStream.Write(bytInput, 0, bytInput.Length)
objCryptStream.Close()
objFileStream.Close()
End Sub
Public Function LoadEncryptedFile(ByVal Key() As Byte, ByVal IV() As Byte, ByVal Filename As String) As String
Dim objFileStream As New System.IO.FileStream(Filename, System.IO.FileMode.Open, System.IO.FileAccess.Read)
Dim objDES As New DESCryptoServiceProvider()
objDES.Key = Key
objDES.IV = IV
Dim objDESDecrypt As ICryptoTransform = objDES.CreateDecryptor()
Dim objCryptStream As New CryptoStream(objFileStream, objDESDecrypt, CryptoStreamMode.Read)
LoadEncryptedFile = New System.IO.StreamReader(objCryptStream, New System.Text.UnicodeEncoding()).ReadToEnd()
objCryptStream.Close()
objFileStream.Close()
End Function
End Module
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