From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 26 Sep 2019 23:03:57 +0000 (+0300)
Subject: Fix several errors in FormData parsing
X-Git-Url: http://git.tdb.fi/?a=commitdiff_plain;h=9a62e48662f6328515ebf256e24762d856b8ce15;p=libs%2Fnet.git

Fix several errors in FormData parsing

It was terminating early if a part happened to be of certain length.
Extra whitespace was included at the end of parts and there was also an
out-of-bounds memory access.
---

diff --git a/source/http/formdata.cpp b/source/http/formdata.cpp
index 182c5bb..9897bc5 100644
--- a/source/http/formdata.cpp
+++ b/source/http/formdata.cpp
@@ -53,15 +53,15 @@ void FormData::parse_multipart(const Request &req, const string &boundary)
 
 		if(is_boundary)
 		{
-			/* The CRLF preceding the boundary delimiter is treated as part
-			of the delimiter as per RFC 2046 */
-			string::size_type part_end = line_start-1;
-			if(content[part_end-1]=='\r')
-				--part_end;
-
 			if(part_start>0)
 			{
-				SubMessage part = SubMessage::parse(content.substr(part_start, line_start-part_start));
+				/* The CRLF preceding the boundary delimiter is treated as part
+				of the delimiter as per RFC 2046 */
+				string::size_type part_end = line_start-1;
+				if(content[part_end-1]=='\r')
+					--part_end;
+
+				SubMessage part = SubMessage::parse(content.substr(part_start, part_end-part_start));
 				Header content_disposition(part, "Content-Disposition");
 				const Header::Value &cd_value = content_disposition.values.at(0);
 				if(cd_value.value=="form-data")
@@ -72,10 +72,10 @@ void FormData::parse_multipart(const Request &req, const string &boundary)
 			}
 
 			part_start = lf+1;
-		}
 
-		if(!content.compare(line_start+2+boundary.size(), 2, "--"))
-			break;
+			if(!content.compare(line_start+2+boundary.size(), 2, "--"))
+				break;
+		}
 
 		line_start = lf+1;
 	}