Keep better track of multipart epilogues

Fixes issue #181
jstedfast · Oct 16, 2015 · 9a558da · 9a558da
1 parent 5796905
commit 9a558da
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Showing 5 changed files with 2,868 additions and 7 deletions.
diff --git a/MimeKit/MimeParser.cs b/MimeKit/MimeParser.cs
@@ -1210,10 +1210,33 @@ unsafe BoundaryType MultipartScanPreamble (Multipart multipart, byte* inbuf)
 			}
 		}
 
+		static bool EndsWithLineFeed (MemoryStream memory)
+		{
+			byte[] buffer;
+
+			if (memory.Length == 0)
+				return false;
+
+#if !PORTABLE && !COREFX
+			buffer = memory.GetBuffer ();
+#else
+			buffer = new byte[1];
+
+			memory.Seek (-1, SeekOrigin.End);
+			memory.Read (buffer, 0, 1);
+#endif
+
+			return buffer[buffer.Length - 1] == (byte) '\n';
+		}
+
 		unsafe BoundaryType MultipartScanEpilogue (Multipart multipart, byte* inbuf)
 		{
 			using (var memory = new MemoryStream ()) {
-				var found = ScanContent (inbuf, memory, true);
+				var found = ScanContent (inbuf, memory, false);
+
+				if (found == BoundaryType.Eos && !EndsWithLineFeed (memory))
+					memory.Write (FormatOptions.Default.NewLineBytes, 0, FormatOptions.Default.NewLineBytes.Length);
+
 				multipart.RawEpilogue = memory.ToArray ();
 				return found;
 			}

diff --git a/MimeKit/Multipart.cs b/MimeKit/Multipart.cs
@@ -205,7 +205,7 @@ public string Preamble {
 				return preamble;
 			}
 			set {
-				if (preamble == value)
+				if (Preamble == value)
 					return;
 
 				if (value != null) {
@@ -227,8 +227,9 @@ internal byte[] RawEpilogue {
 		/// Gets or sets the epilogue.
 		/// </summary>
 		/// <remarks>
-		/// A multipart epiloque is the text that ppears after the last
-		/// child of the multipart and is rarely ever used.
+		/// A multipart epiloque is the text that appears after the closing boundary
+		/// of the multipart and is typically either empty or a single new line
+		/// character sequence.
 		/// </remarks>
 		/// <value>The epilogue.</value>
 		public string Epilogue {
@@ -239,7 +240,7 @@ public string Epilogue {
 				return epilogue;
 			}
 			set {
-				if (epilogue == value)
+				if (Epilogue == value)
 					return;
 
 				if (value != null) {
@@ -415,7 +416,9 @@ public override void Prepare (EncodingConstraint constraint, int maxLineLength =
 				}
 
 				cancellable.Write (boundary, 0, boundary.Length, cancellationToken);
-				cancellable.Write (options.NewLineBytes, 0, options.NewLineBytes.Length, cancellationToken);
+
+				if (RawEpilogue == null)
+					cancellable.Write (options.NewLineBytes, 0, options.NewLineBytes.Length, cancellationToken);
 			} else {
 				for (int i = 0; i < children.Count; i++) {
 					cancellationToken.ThrowIfCancellationRequested ();
@@ -427,7 +430,9 @@ public override void Prepare (EncodingConstraint constraint, int maxLineLength =
 
 				cancellationToken.ThrowIfCancellationRequested ();
 				stream.Write (boundary, 0, boundary.Length);
-				stream.Write (options.NewLineBytes, 0, options.NewLineBytes.Length);
+
+				if (RawEpilogue == null)
+					stream.Write (options.NewLineBytes, 0, options.NewLineBytes.Length);
 			}
 
 			if (RawEpilogue != null && RawEpilogue.Length > 0)

diff --git a/UnitTests/DkimTests.cs b/UnitTests/DkimTests.cs
@@ -157,6 +157,25 @@ public void TestVerifyGoogleMailDkimSignature ()
 			Assert.IsTrue (message.Verify (message.Headers[index], new DummyPublicKeyLocator (key)), "Failed to verify GMail signature.");
 		}
 
+		[Test]
+		public void TestVerifyGoogleMultipartRelatedDkimSignature ()
+		{
+			var message = MimeMessage.Load (Path.Combine ("..", "..", "TestData", "dkim", "related.msg"));
+			int index = message.Headers.IndexOf (HeaderId.DkimSignature);
+			AsymmetricKeyParameter key;
+
+			var txt = message.ToString ().Substring (1100, 2400);
+
+			// Note: you can use http://dkimcore.org/tools/dkimrecordcheck.html to get public keys manually
+			using (var stream = new StreamReader (Path.Combine ("..", "..", "TestData", "dkim", "gmail.pub"))) {
+				var reader = new PemReader (stream);
+
+				key = reader.ReadObject () as AsymmetricKeyParameter;
+			}
+
+			Assert.IsTrue (message.Verify (message.Headers[index], new DummyPublicKeyLocator (key)), "Failed to verify GMail signature.");
+		}
+
 		static void TestDkimSignVerify (MimeMessage message, DkimSignatureAlgorithm signatureAlgorithm, DkimCanonicalizationAlgorithm headerAlgorithm, DkimCanonicalizationAlgorithm bodyAlgorithm)
 		{
 			var headers = new HeaderId[] { HeaderId.From, HeaderId.Subject, HeaderId.Date };