>Someone on the opendkim-users list has pointed out that DKIM >signatures are being invalidated when re-mailed through one >particular MLM that rewrites Content-Type: so that its value is all >lowercase. Obviously this is a problem for DKIM since even "relaxed" >requires nothing other than spacing changes in header field values; >however RFC2045 says that the interpretation of Content-Type: values >is case-insensitive. Thus, at least to consumers of that header >field, DKIM is doing something "wrong". In any case, it was >suggested on that list that "relaxed" header canonicalization be >adjusted to accommodate this.
Although I see the point in this particular case, it seems to me that it would be a hopeless rathole to try to catalog and account for all of the semantics of every possible header line and the set of possible modifications to each header that do or do not make a semantic difference. Looking at the RFCs, I can't tell whether the boundary string in Content-Type: is supposed to be case sensitive, but the addresses in To:, From:, Cc;, and so forth certainly are, and I wouldn't want to get into an argument about whether the Subject: line is. R's, John PS: Needless to say, this supports my observation that the number of list managers that don't break DKIM signature is insignificant. _______________________________________________ NOTE WELL: This list operates according to http://mipassoc.org/dkim/ietf-list-rules.html
