Fixed extraction of TNEF EmbeddedMessage attachment data to skip the …

…leading GUID Final fix for issue #538
jstedfast · Mar 6, 2020 · c739051 · c739051
1 parent 34a4d29
commit c739051
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Showing 6 changed files with 23 additions and 18 deletions.
diff --git a/MimeKit/Tnef/TnefPart.cs b/MimeKit/Tnef/TnefPart.cs
@@ -380,7 +380,6 @@ static TnefPart PromoteToTnefPart (MimePart part)
 				tnef.ContentDisposition = part.ContentDisposition;
 
 			tnef.ContentTransferEncoding = part.ContentTransferEncoding;
-			tnef.Content = part.Content;
 
 			return tnef;
 		}
@@ -410,6 +409,8 @@ static void ExtractAttachments (TnefReader reader, BodyBuilder builder)
 					if (attachment == null)
 						break;
 
+					attachData = null;
+
 					while (prop.ReadNextProperty ()) {
 						switch (prop.PropertyTag.Id) {
 						case TnefPropertyId.AttachLongFilename:
@@ -440,25 +441,10 @@ static void ExtractAttachments (TnefReader reader, BodyBuilder builder)
 								attachment.ContentDisposition = disposition;
 							break;
 						case TnefPropertyId.AttachData:
-							if (attachMethod == TnefAttachMethod.EmbeddedMessage)
-								attachment = PromoteToTnefPart (attachment);
-
 							attachData = prop.ReadValueAsBytes ();
-							filter.Flush (attachData, 0, attachData.Length, out outIndex, out outLength);
-							attachment.ContentTransferEncoding = filter.GetBestEncoding (EncodingConstraint.SevenBit);
-							attachment.Content = new MimeContent (new MemoryStream (attachData, false));
-							filter.Reset ();
-
-							builder.Attachments.Add (attachment);
 							break;
 						case TnefPropertyId.AttachMethod:
 							attachMethod = (TnefAttachMethod) prop.ReadValueAsInt32 ();
-
-							if (attachMethod == TnefAttachMethod.EmbeddedMessage) {
-								builder.Attachments.Remove (attachment);
-								attachment = PromoteToTnefPart (attachment);
-								builder.Attachments.Add (attachment);
-							}
 							break;
 						case TnefPropertyId.AttachMimeTag:
 							mimeType = prop.ReadValueAsString ().Split ('/');
@@ -487,6 +473,25 @@ static void ExtractAttachments (TnefReader reader, BodyBuilder builder)
 							break;
 						}
 					}
+
+					if (attachData != null) {
+						int count = attachData.Length;
+						int index = 0;
+
+						if (attachMethod == TnefAttachMethod.EmbeddedMessage) {
+							attachment.ContentTransferEncoding = ContentEncoding.Base64;
+							attachment = PromoteToTnefPart (attachment);
+							count -= 16;
+							index = 16;
+						} else {
+							filter.Flush (attachData, index, count, out outIndex, out outLength);
+							attachment.ContentTransferEncoding = filter.GetBestEncoding (EncodingConstraint.SevenBit);
+							filter.Reset ();
+						}
+
+						attachment.Content = new MimeContent (new MemoryStream (attachData, index, count, false));
+						builder.Attachments.Add (attachment);
+					}
 					break;
 				case TnefAttributeTag.AttachCreateDate:
 					if (attachment != null) {

diff --git a/UnitTests/TestData/tnef/christmas/Untitled Attachment.1 b/UnitTests/TestData/tnef/christmas/Untitled Attachment.1
diff --git a/UnitTests/TestData/tnef/christmas/Untitled Attachment.2 b/UnitTests/TestData/tnef/christmas/Untitled Attachment.2
diff --git a/UnitTests/TestData/tnef/christmas/Untitled Attachment.3 b/UnitTests/TestData/tnef/christmas/Untitled Attachment.3
diff --git a/UnitTests/TestData/tnef/christmas/Untitled Attachment.4 b/UnitTests/TestData/tnef/christmas/Untitled Attachment.4
diff --git a/UnitTests/Tnef/TnefTests.cs b/UnitTests/Tnef/TnefTests.cs
@@ -993,7 +993,7 @@ public void TestRichTextEml ()
 			Assert.AreEqual (9217, task1.ContentDisposition.Size, "Size");
 
 			var task2 = (MimePart) multipart[3];
-			Assert.AreEqual ("application/octet-stream", task2.ContentType.MimeType, "MimeType");
+			Assert.AreEqual ("application/vnd.ms-tnef", task2.ContentType.MimeType, "MimeType");
 			Assert.AreEqual ("Build a train table", task2.ContentType.Name, "Name");
 			Assert.AreEqual ("attachment", task2.ContentDisposition.Disposition, "Disposition");
 			Assert.AreEqual ("Untitled Attachment", task2.ContentDisposition.FileName, "FileName");
@@ -1009,7 +1009,7 @@ public void TestRichTextEml ()
 			Assert.AreEqual (387453, appointment1.ContentDisposition.Size, "Size");
 
 			var appointment2 = (MimePart) multipart[5];
-			Assert.AreEqual ("application/octet-stream", appointment2.ContentType.MimeType, "MimeType");
+			Assert.AreEqual ("application/vnd.ms-tnef", appointment2.ContentType.MimeType, "MimeType");
 			Assert.AreEqual ("Christmas Celebration!", appointment2.ContentType.Name, "Name");
 			Assert.AreEqual ("attachment", appointment2.ContentDisposition.Disposition, "Disposition");
 			Assert.AreEqual ("Untitled Attachment", appointment2.ContentDisposition.FileName, "FileName");