From 0e2ed68f9e22b77937900700cc50575729a42a0f Mon Sep 17 00:00:00 2001
From: Jonathan Jenne <j.jenne@digitaldata.works>
Date: Fri, 28 May 2021 10:57:50 +0200
Subject: [PATCH] Encryption: Return original value on error

---
 Encryption/EncryptionLegacy.vb | 88 +++++++++++++++++-----------------
 1 file changed, 44 insertions(+), 44 deletions(-)

diff --git a/Encryption/EncryptionLegacy.vb b/Encryption/EncryptionLegacy.vb
index 784cab60..582ee55c 100644
--- a/Encryption/EncryptionLegacy.vb
+++ b/Encryption/EncryptionLegacy.vb
@@ -5,6 +5,7 @@ Imports System.Data.SqlClient
 Public Class EncryptionLegacy
     Private TripleDes As New TripleDESCryptoServiceProvider
     Private DEFAULT_KEY As String = "!35452didalog="
+    Private SALT_VALUE As String = "!Didalog35452Heuchelheim="
 
     Sub New()
         TripleDes.Key = TruncateHash(DEFAULT_KEY, TripleDes.KeySize \ 8)
@@ -31,53 +32,52 @@ Public Class EncryptionLegacy
     End Function
 
     Public Function EncryptData(ByVal plaintext As String) As String
-
-        ' Convert the plaintext string to a byte array.
-        Dim plaintextBytes() As Byte =
-            System.Text.Encoding.Unicode.GetBytes("!Didalog35452Heuchelheim=" & plaintext)
-
-        ' Create the stream.
-        Dim ms As New System.IO.MemoryStream
-        ' Create the encoder to write to the stream.
-        Dim encStream As New CryptoStream(ms,
-            TripleDes.CreateEncryptor(),
-            System.Security.Cryptography.CryptoStreamMode.Write)
-
-        ' Use the crypto stream to write the byte array to the stream.
-        encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
-        encStream.FlushFinalBlock()
-
-        ' Convert the encrypted stream to a printable string.
-        Return Convert.ToBase64String(ms.ToArray)
+        Try
+            ' Convert the plaintext string to a byte array.
+            Dim plaintextBytes() As Byte =
+                System.Text.Encoding.Unicode.GetBytes(SALT_VALUE & plaintext)
+
+            ' Create the stream.
+            Dim ms As New System.IO.MemoryStream
+            ' Create the encoder to write to the stream.
+            Dim encStream As New CryptoStream(ms,
+                TripleDes.CreateEncryptor(),
+                System.Security.Cryptography.CryptoStreamMode.Write)
+
+            ' Use the crypto stream to write the byte array to the stream.
+            encStream.Write(plaintextBytes, 0, plaintextBytes.Length)
+            encStream.FlushFinalBlock()
+
+            ' Convert the encrypted stream to a printable string.
+            Return Convert.ToBase64String(ms.ToArray)
+        Catch ex As Exception
+            Return plaintext
+        End Try
     End Function
 
     'Entschlüsselt die Zeichenfolge
-    Public Function DecryptData(ByVal encryptedtext As String) As String
-        ' Convert the encrypted text string to a byte array.
-        Dim encryptedBytes() As Byte = Convert.FromBase64String(encryptedtext)
-
-        ' Create the stream.
-        Dim ms As New System.IO.MemoryStream
-        ' Create the decoder to write to the stream.
-        Dim decStream As New CryptoStream(ms,
-            TripleDes.CreateDecryptor(),
-            System.Security.Cryptography.CryptoStreamMode.Write)
-
-        ' Use the crypto stream to write the byte array to the stream.
-        decStream.Write(encryptedBytes, 0, encryptedBytes.Length)
-        decStream.FlushFinalBlock()
-        Dim result = System.Text.Encoding.Unicode.GetString(ms.ToArray)
-        result = result.Replace("!Didalog35452Heuchelheim=", "")
-        ' Convert the plaintext stream to a string.
-        Return result
-    End Function
-
-    Public Function DecryptConnectionString(ConnectionString As String) As String
-        Dim oBuilder As New SqlConnectionStringBuilder() With {.ConnectionString = ConnectionString}
-        Dim oDecryptedPassword = DecryptData(oBuilder.Password)
-        oBuilder.Password = oDecryptedPassword
-
-        Return oBuilder.ToString()
+    Public Function DecryptData(ByVal EncryptedText As String) As String
+        Try
+            ' Convert the encrypted text string to a byte array.
+            Dim oEncryptedBytes() As Byte = Convert.FromBase64String(EncryptedText)
+
+            ' Create the stream.
+            Dim oMemoryStream As New System.IO.MemoryStream
+            ' Create the decoder to write to the stream.
+            Dim oCryptoStream As New CryptoStream(oMemoryStream,
+                TripleDes.CreateDecryptor(),
+                System.Security.Cryptography.CryptoStreamMode.Write)
+
+            ' Use the crypto stream to write the byte array to the stream.
+            oCryptoStream.Write(oEncryptedBytes, 0, oEncryptedBytes.Length)
+            oCryptoStream.FlushFinalBlock()
+            Dim oResult = System.Text.Encoding.Unicode.GetString(oMemoryStream.ToArray)
+            oResult = oResult.Replace(SALT_VALUE, "")
+            ' Convert the plaintext stream to a string.
+            Return oResult
+        Catch ex As Exception
+            Return EncryptedText
+        End Try
     End Function
 End Class