* Paul Hoffman <[EMAIL PROTECTED]> [2007-06-19 21:40]: > The method for a server to indicate to a third party whether or > not the client signed an Entry Document is by including the > client's signature in the published entry, even though that > signature is likely to be invalid.
I strongly disagree with this. As a consumer, I have no possible way to know whether an invalid signature is there because • the publishing client included it • the server made up a signature to feign signing by the client • a third party tampered with the entry between the server and me Therefore as a consumer I would never ever assume that an invalid signature meant anything else than that the signature on this entry is not valid. Encouraging servers to knowingly include signatures they have invalidated is Just. Wrong. It dilutes the value of signatures as a whole by making it harder for the consumer to decide what an invalid signature means, which by extension also blurs the trust conferred by a valid signature. It’s fine for the server to be signature-agnostic. If the server is not, though, then it really should strip the signature if it knows it has invalidated it. Note that my proposed text said “strongly encouraged”, not “SHOULD”. After all, it is not an interop concern, nor do I desire to dictate server behaviour. However, I do think this particular implementation choice makes a lot of sense and should be the default choice for server implementors who don’t have specific reason to do things otherwise. And I think the spec should nudge them in that direction. Regards, -- Aristotle Pagaltzis // <http://plasmasturm.org/>
