From 2f5bec7bb67c0050fd66eca072841162afb229af Mon Sep 17 00:00:00 2001
From: Jonathan Jenne <j.jenne@digitaldata.works>
Date: Mon, 25 Sep 2023 08:49:26 +0200
Subject: [PATCH] Only allow predefined extensions

---
 Connectors.Common/Connectors.Common.vbproj    |  1 +
 Connectors.Common/Modules/Constants.vb        | 26 +++++++++++++++++
 .../Modules/slt/Entities/sltDocument.vb       | 29 +++++++++++++++----
 Connectors.Test/sltTest.vb                    | 13 ++++++++-
 4 files changed, 63 insertions(+), 6 deletions(-)
 create mode 100644 Connectors.Common/Modules/Constants.vb

diff --git a/Connectors.Common/Connectors.Common.vbproj b/Connectors.Common/Connectors.Common.vbproj
index 9add4c6..7c5a5ff 100644
--- a/Connectors.Common/Connectors.Common.vbproj
+++ b/Connectors.Common/Connectors.Common.vbproj
@@ -84,6 +84,7 @@
   <ItemGroup>
     <Compile Include="Config.vb" />
     <Compile Include="Modules\BaseModule.vb" />
+    <Compile Include="Modules\Constants.vb" />
     <Compile Include="Modules\ISync.vb" />
     <Compile Include="Modules\Sharepoint\Constants.vb" />
     <Compile Include="Modules\Sharepoint\Entities\SharepointDocument.vb" />
diff --git a/Connectors.Common/Modules/Constants.vb b/Connectors.Common/Modules/Constants.vb
new file mode 100644
index 0000000..101e795
--- /dev/null
+++ b/Connectors.Common/Modules/Constants.vb
@@ -0,0 +1,26 @@
+Public Class Constants
+    Public Shared Property AllowedExtensions As New List(Of String) From {
+            "pdf",
+            "txt",
+            "pptx",
+            "docx",
+            "xlsx",
+            "ppt",
+            "doc",
+            "xls",
+            "msg",
+            "csv",
+            "dxf",
+            "dwg",
+            "jpg",
+            "jpeg",
+            "png",
+            "zip",
+            "7z",
+            "mp4",
+            "log",
+            "jfif",
+            "bmp",
+            "eml"
+        }
+End Class
diff --git a/Connectors.Common/Modules/slt/Entities/sltDocument.vb b/Connectors.Common/Modules/slt/Entities/sltDocument.vb
index dd05c64..8ae0b4b 100644
--- a/Connectors.Common/Modules/slt/Entities/sltDocument.vb
+++ b/Connectors.Common/Modules/slt/Entities/sltDocument.vb
@@ -1,5 +1,4 @@
 Imports System.IO
-Imports DigitalData.Modules.Base
 
 Namespace slt.Entities
     Public Class sltDocument
@@ -25,13 +24,33 @@ Namespace slt.Entities
         End Function
 
         Private Function GetExtension() As String
-            If Path.HasExtension(DocOriginalFilename) Then
-                Return Path.GetExtension(DocOriginalFilename)
-            ElseIf Path.HasExtension(Name) Then
-                Return Path.GetExtension(Name)
+            Dim oExtensionFromName = GetAllowedExtension(Name)
+            If oExtensionFromName IsNot Nothing Then
+                Return oExtensionFromName
+            End If
+
+            Dim oExtensionFromOriginalName = GetAllowedExtension(DocOriginalFilename)
+            If oExtensionFromOriginalName IsNot Nothing Then
+                Return oExtensionFromOriginalName
+            End If
+
+            Return Nothing
+        End Function
+
+        Private Function GetAllowedExtension(pFilename As String) As String
+            If Path.HasExtension(pFilename) Then
+                Dim oExtension = Path.GetExtension(pFilename)
+                Dim oExtensionWithoutDot = oExtension.Substring(1).ToLower()
+
+                If Common.Constants.AllowedExtensions.Contains(oExtensionWithoutDot) Then
+                    Return oExtension
+                Else
+                    Return Nothing
+                End If
             Else
                 Return Nothing
             End If
         End Function
+
     End Class
 End Namespace
diff --git a/Connectors.Test/sltTest.vb b/Connectors.Test/sltTest.vb
index 3c4a9f7..6ef55f5 100644
--- a/Connectors.Test/sltTest.vb
+++ b/Connectors.Test/sltTest.vb
@@ -22,6 +22,12 @@ Namespace Connectors.Test.slt
             .Name = "Gutschrift-[TITEL].pdf"
         }
 
+        Public oDocument4 As New sltDocument With {
+            .ExtDocId = "DOCID",
+            .DocOriginalFilename = "TWZ Einbau - Pilgerweg 8 vom 20.07.2022.jpg",
+            .Name = "TWZ Einbau - Pilgerweg 8 vom 20.07.2022"
+        }
+
         <TestMethod>
         Sub GetExtensionTest1()
             Assert.AreEqual("DOCID.dwg", oDocument1.GetUniqueFilename())
@@ -29,7 +35,7 @@ Namespace Connectors.Test.slt
 
         <TestMethod>
         Sub GetExtensionTest2()
-            Assert.AreEqual("", oDocument2.GetUniqueFilename())
+            Assert.AreEqual(Nothing, oDocument2.GetUniqueFilename())
         End Sub
 
         <TestMethod>
@@ -37,6 +43,11 @@ Namespace Connectors.Test.slt
             Assert.AreEqual("DOCID.pdf", oDocument3.GetUniqueFilename())
         End Sub
 
+        <TestMethod>
+        Sub GetExtensionTest4()
+            Assert.AreEqual("DOCID.jpg", oDocument4.GetUniqueFilename())
+        End Sub
+
     End Class
 
 End Namespace