MS Common V 1.5 New paths for email-Service

EnvelopeGenerator.Common/Helpers.vb

@@ -1,9 +1,28 @@
 Imports System.Drawing
 Imports System.IO
+Imports System.Security.Cryptography
+Imports System.Text
 Imports DevExpress.Utils.Svg
 Imports EnvelopeGenerator.Common.Constants
 
 Public Class Helpers
+    Private Shared key As String = "$xzBvyPETUS&amm8)D8x#)f;4%;?[BPd" ' Passwort-Schlüssel (16, 24, or 32 bytes)
+    Private Shared iv As String = "1wN&e[zrQ6_B7X/0" ' Initialisierungsvektor (16 bytes)
+
+    ' Entschlüsselungsfunktion
+    Public Shared Function Decrypt(cipherText As String) As String
+        Dim aesAlg As Aes = Aes.Create()
+        aesAlg.Key = Encoding.UTF8.GetBytes(key)
+        aesAlg.IV = Encoding.UTF8.GetBytes(iv)
+        Dim decryptor As ICryptoTransform = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV)
+        Dim cipherBytes As Byte() = Convert.FromBase64String(cipherText)
+        Dim msDecrypt As New IO.MemoryStream(cipherBytes)
+        Using csDecrypt As New CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read)
+            Using srDecrypt As New IO.StreamReader(csDecrypt)
+                Return srDecrypt.ReadToEnd()
+            End Using
+        End Using
+    End Function
 
     ''' <summary>
     ''' Encodes the EnvelopeUUID and the ReceiverSignature into an EnvelopeKey