Imagine a user asks for Rage: bytes=2-5 of a 10-byte file. What MD5 sum has to be served to the user? The MD5 sum of all 10 bytes or only of the partial content, bytes 2-5?
RFC2616 Section 14.15 reads:
The MD5 digest is computed based on
the content of the entity-body,
including any content-coding that has
been applied, but not including any
transfer-encoding applied to the
message-body. If the message is
received with a transfer-encoding,
that encoding MUST be removed prior to
checking the Content-MD5 value against
the received entity.
How must I interpret that? I ask this because I would refrain from adding md5sums to partial content, iff it has to be re-generated for each range-request.
This is: http://trac.tools.ietf.org/wg/httpbis/trac/ticket/178.
So there is no easy answer, the Working Group will gladly accept feedback.