I found some coding with which I can encrypt/decrypt at:
http://kellychronicles.spaces.live.c...DBF8!593.entry
Now I wanted to change the coding so there allready is a string and key set.
(I know not very secure, but it suits my purpose).
Anyways I'm getting an 'Invalid key' error while decrypting.. :S How come? The key is set in the beginning, so there can't be any other key.
Code:
Imports System.IO
Imports System.Text
Imports System.Security.Cryptography
Public Class Form1
Dim line1 As String = "just a testing string"
Dim key As String = "today"
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
TextBox1.Text = Crypto.Encrypt(line1, key)
End Sub
Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
TextBox1.Text = Crypto.Decrypt(line1, key)
End Sub
End Class
Public Class Crypto
Private Shared DES As New TripleDESCryptoServiceProvider
Private Shared MD5 As New MD5CryptoServiceProvider
Public Shared Function MD5Hash(ByVal value As String) As Byte()
Return MD5.ComputeHash(ASCIIEncoding.ASCII.GetBytes(value))
End Function
Public Shared Function Encrypt(ByVal stringToEncrypt As String, ByVal key As String) As String
DES.Key = Crypto.MD5Hash(key)
DES.Mode = CipherMode.ECB
Dim Buffer As Byte() = ASCIIEncoding.ASCII.GetBytes(stringToEncrypt)
Return Convert.ToBase64String(DES.CreateEncryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
End Function
Public Shared Function Decrypt(ByVal encryptedString As String, ByVal key As String) As String
Try
DES.Key = Crypto.MD5Hash(key)
DES.Mode = CipherMode.ECB
Dim Buffer As Byte() = Convert.FromBase64String(encryptedString)
Return ASCIIEncoding.ASCII.GetString(DES.CreateDecryptor().TransformFinalBlock(Buffer, 0, Buffer.Length))
Catch ex As Exception
MessageBox.Show("Invalid Key", "Decryption Failed", MessageBoxButtons.OK, MessageBoxIcon.Exclamation)
End Try
End Function
End Class
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