2RFC 6376, "DomainKeys Identified Mail (DKIM) Signatures", September 2011
3Source of RFC: dkim (art)
4See Also: RFC 6376 w/ inline errata
9Publication Format(s) : TEXT
10Reported By: Chris Newman
11Date Reported: 2017-07-15
12Verifier Name: Barry Leiba
13Date Verified: 2019-04-30
17 tag-spec = [FWS] tag-name [FWS] "=" [FWS] tag-value [FWS]
18 tag-name = ALPHA *ALNUMPUNC
19 tag-value = [ tval *( 1*(WSP / FWS) tval ) ]
20 ; Prohibits WSP and FWS at beginning and end
23 tag-spec = [FWS] tag-name [FWS] "=" [FWS] [tag-value [FWS]]
24 tag-name = ALPHA *ALNUMPUNC
25 tag-value = tval *( 1*(WSP / FWS) tval )
26 ; Prohibits WSP and FWS at beginning and end
30The ABNF in the document permits two FWS rules to appear in the row. This results in permitting a line with only whitespace in the header which falls into obsolete syntax in RFC 5322 (Appendix B rule 12). The corrected text disallows this by eliding the second FWS when the tag-value is empty/omitted.