On Wed, 18 Jun 2008, [EMAIL PROTECTED] wrote: > [ not about ADSP, about DKIM ] > > An acquaintance points out that one could prepend an extra From: or > Subject: header to a DKIM signed message, which wouldn't break the > signature, but would often be displayed by MUAs which show the new one > rather than the old one. Needless to say, that weakens the practical > benefit of DKIM for people with MUAs like that.
It could break the signature. Presumably the original message signed the first From: header field. Depending on the placement of the new one, the verifier might use the new one or might use the old one. That will affect the validation process. > My theory is that DKIM only applies to valid 2822 messages, and it's not > a substitute for a sanity check for all the screwy things one can send > in a non-conformant message. Perhaps it would be a good idea someday to > collect experience and advice into an implmentation guide, but other > than that, it's not our problem. Agreed? +1, and I would go even further to say that we should have an errata item against RFC4871 which says we should add that DKIM presumes a properly-formed RFC2822-style message, and that its application to other messages produces undefined results. _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
