Reject requests with oversized chunk bodies #43
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This PR tightens the parsing of chunked HTTP requests by rejecting requests with oversized chunks. By oversized chunks, I mean chunks where the body exceeds the chunk size indicated in the chunk header. E.g.:
Currently, pound logs this error, but 'allows it' (i.e. forwards the entire chunk as-is and lets the backend deal with it).
This behaviour is incorrect, and it can cause problems with some backends. Specifically, some HTTP parsers accept any 2-byte sequence as the line terminator of a chunk body (not checking that it is in fact a CRLF sequence). In such cases, pound and the backend will interpret the chunk boundaries differently, which can potentially lead to a request smuggling vulnerability.