Imports System.Security.Cryptography
Imports System.IO
Imports System.Text
Public Class Form1
Dim customerName As String
Dim expirationDate As String
Dim serverName As String
Dim passPhrase As String = "MickeyScentMe"
Dim saltValue As String = "NaCl4AllF00ds"
Dim hashAlgorithm As String = "SHA1"
Dim passwordIterations As Integer = 2
Dim initVector As String = "@1B2c3D4e5F6g7H8"
Dim keySize As Integer = 256
Dim baseDir = Path.GetDirectoryName(Application.ExecutablePath) 'Application.ExecutablePath
Private Function GetStringToEncrypt() As String
Dim source As String
source = String.Format("{0}|{1}|{2}|{3}", "RUNBIZ", serverName, customerName, expirationDate)
Return source
End Function
Private Function GetValues() As Boolean
lblStatus.ForeColor = Color.Red
customerName = txtCustomerName.Text.Trim().ToUpper()
If String.IsNullOrEmpty(customerName) Then
lblStatus.Text = "Customer name cannnot be blank."
Return False
End If
expirationDate = dtpExpirationDate.Value.ToString("MMddyyyy")
serverName = txtServerName.Text.Trim().ToUpper()
If String.IsNullOrEmpty(serverName) Then
lblStatus.Text = "Server name cannnot be blank."
Return False
End If
Return True
End Function
Public Function Encrypt(ByVal plainText As String) As String
Dim initVectorBytes As Byte() = Encoding.ASCII.GetBytes(initVector)
Dim saltValueBytes As Byte() = Encoding.ASCII.GetBytes(saltValue)
Dim plainTextBytes As Byte() = Encoding.UTF8.GetBytes(plainText)
Dim password As New PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations)
Dim keyBytes As Byte() = password.GetBytes(keySize \ 8)
Dim symmetricKey As New RijndaelManaged()
symmetricKey.Mode = CipherMode.CBC
Dim encryptor As ICryptoTransform = symmetricKey.CreateEncryptor(keyBytes, initVectorBytes)
Dim memoryStream As New MemoryStream()
Dim cryptoStream As New CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write)
cryptoStream.Write(plainTextBytes, 0, plainTextBytes.Length)
cryptoStream.FlushFinalBlock()
Dim cipherTextBytes As Byte() = memoryStream.ToArray()
memoryStream.Close()
cryptoStream.Close()
Dim cipherText As String = Convert.ToBase64String(cipherTextBytes)
Return cipherText
End Function
Public Function Decrypt(ByVal cipherText As String) As String
' Convert strings defining encryption key characteristics into byte
' arrays. Let us assume that strings only contain ASCII codes.
' If strings include Unicode characters, use Unicode, UTF7, or UTF8
' encoding.
Dim initVectorBytes As Byte() = Encoding.ASCII.GetBytes(initVector)
Dim saltValueBytes As Byte() = Encoding.ASCII.GetBytes(saltValue)
' Convert our ciphertext into a byte array.
Dim cipherTextBytes As Byte() = Convert.FromBase64String(cipherText)
' First, we must create a password, from which the key will be
' derived. This password will be generated from the specified
' passphrase and salt value. The password will be created using
' the specified hash algorithm. Password creation can be done in
' several iterations.
Dim password As New PasswordDeriveBytes(passPhrase, saltValueBytes, hashAlgorithm, passwordIterations)
' Use the password to generate pseudo-random bytes for the encryption
' key. Specify the size of the key in bytes (instead of bits).
Dim keyBytes As Byte() = password.GetBytes(keySize \ 8)
' Create uninitialized Rijndael encryption object.
Dim symmetricKey As New RijndaelManaged()
' It is reasonable to set encryption mode to Cipher Block Chaining
' (CBC). Use default options for other symmetric key parameters.
symmetricKey.Mode = CipherMode.CBC
' Generate decryptor from the existing key bytes and initialization
' vector. Key size will be defined based on the number of the key
' bytes.
Dim decryptor As ICryptoTransform = symmetricKey.CreateDecryptor(keyBytes, initVectorBytes)
' Define memory stream which will be used to hold encrypted data.
Dim memoryStream As New MemoryStream(cipherTextBytes)
' Define cryptographic stream (always use Read mode for encryption).
Dim cryptoStream As New CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read)
' Since at this point we don't know what the size of decrypted data
' will be, allocate the buffer long enough to hold ciphertext;
' plaintext is never longer than ciphertext.
Dim plainTextBytes As Byte() = New Byte(cipherTextBytes.Length - 1) {}
' Start decrypting.
Dim decryptedByteCount As Integer = cryptoStream.Read(plainTextBytes, 0, plainTextBytes.Length)
' Close both streams.
memoryStream.Close()
cryptoStream.Close()
' Convert decrypted data into a string.
' Let us assume that the original plaintext string was UTF8-encoded.
Dim plainText As String = Encoding.UTF8.GetString(plainTextBytes, 0, decryptedByteCount)
' Return decrypted string.
Return plainText
End Function
Private Function CreateKey() As String
Dim plainText As String = GetStringToEncrypt()
plainText = plainText.PadRight(64, " ")
Dim strEncryptedText As String
strEncryptedText = Encrypt(plainText)
lblEncryptedText.Text = strEncryptedText
Dim strDecrptedText As String
strDecrptedText = Decrypt(strEncryptedText).Trim()
lblPlainText.Text = strDecrptedText
Return strEncryptedText
End Function
Public Sub SaveKey(key As String)
Dim keyDir = Path.Combine(baseDir, customerName.Replace(" ", ""))
Directory.CreateDirectory(keyDir)
File.WriteAllText(Path.Combine(keyDir, "KEY.DAT"), key)
lblStatus.Text = String.Format("Key saved as: {0}\{1}", keyDir, "KEY.DAT")
End Sub
Private Sub btnCreateKey_Click(sender As Object, e As EventArgs) Handles btnCreateKey.Click
Dim encryptedText As String
lblStatus.Text = "Generating Key"
If GetValues() Then
encryptedText = CreateKey()
SaveKey(encryptedText)
End If
End Sub
Private Sub btnExit_Click(sender As Object, e As EventArgs) Handles btnExit.Click
Application.Exit()
End Sub
Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
' Default date to 1 year from today
dtpExpirationDate.Value = DateTime.Now().AddYears(1)
End Sub
End Class