Throw a ParserException in ParseEntity() when the stream does not hav…

…e headers Fixes issue #443
jstedfast · Oct 24, 2018 · 47bc775 · 47bc775
1 parent 5db6b89
commit 47bc775
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Showing 3 changed files with 14 additions and 8 deletions.
diff --git a/MimeKit/AsyncMimeParser.cs b/MimeKit/AsyncMimeParser.cs
@@ -323,7 +323,7 @@ async Task<BoundaryType> ConstructMessagePartAsync (MessagePart part, Cancellati
 			}
 
 			// parse the headers...
-			state = MimeParserState.Headers;
+			state = MimeParserState.MessageHeaders;
 			if (await StepAsync (cancellationToken).ConfigureAwait (false) == MimeParserState.Error) {
 				// Note: this either means that StepHeaders() found the end of the stream
 				// or an invalid header field name at the start of the message headers,

diff --git a/MimeKit/MimeParser.cs b/MimeKit/MimeParser.cs
@@ -779,10 +779,17 @@ unsafe bool StepHeaders (byte* inbuf, ref bool scanningFieldName, ref bool check
 							return false;
 						}
 
-						if (state == MimeParserState.MessageHeaders && headers.Count == 0) {
-							// ignore From-lines that might appear at the start of a message
-							if (length < 5 || !IsMboxMarker (start, true)) {
-								// not a From-line...
+						if (headers.Count == 0) {
+							if (state == MimeParserState.MessageHeaders) {
+								// ignore From-lines that might appear at the start of a message
+								if (length < 5 || !IsMboxMarker (start, true)) {
+									// not a From-line...
+									inputIndex = (int) (start - inbuf);
+									state = MimeParserState.Error;
+									headerIndex = 0;
+									return false;
+								}
+							} else if (state == MimeParserState.Headers) {
 								inputIndex = (int) (start - inbuf);
 								state = MimeParserState.Error;
 								headerIndex = 0;
@@ -832,7 +839,7 @@ unsafe bool StepHeaders (byte* inbuf, ref bool scanningFieldName, ref bool check
 
 				length = (inptr + 1) - start;
 
-				if (!valid && headers.Count == 0 && length > 5 && IsMboxMarker (start, true)) {
+				if (!valid && headers.Count == 0 && length >= 5 && IsMboxMarker (start, true)) {
 					if (inptr[-1] == (byte) '\r')
 						length--;
 					length--;
@@ -1279,7 +1286,7 @@ unsafe BoundaryType ConstructMessagePart (MessagePart part, byte* inbuf, Cancell
 			}
 
 			// parse the headers...
-			state = MimeParserState.Headers;
+			state = MimeParserState.MessageHeaders;
 			if (Step (inbuf, cancellationToken) == MimeParserState.Error) {
 				// Note: this either means that StepHeaders() found the end of the stream
 				// or an invalid header field name at the start of the message headers,

diff --git a/UnitTests/TestData/mbox/jwz.mbox.txt b/UnitTests/TestData/mbox/jwz.mbox.txt
@@ -6595,7 +6595,6 @@ a
 --PART.BOUNDARY.2418.16114.COSMOS.VLSI.CS.CMU.EDU.715029153.2
 Content-type: message/rfc822
 
-26-Aug-92 22:15:02-LCL,22076;000000000000
 Received: from po3.andrew.cmu.edu by COSMOS.VLSI.CS.CMU.EDU id aa13358;
           26 Aug 92 22:14:26 EDT
 Received: from sqhilton.pc.cs.cmu.edu by po3.andrew.cmu.edu (5.54/3.15) id <AA21478> for [email protected]; Wed, 26 Aug 92 22:14:07 EDT