Steffen Nurpmeso via Postfix-users wrote in <20240429215451.hPgOZwzc@steffen%sdaoden.eu>: |Scott Kitterman via Postfix-users wrote in | <53d75fd8-e109-4712-ba9c-4ea07aa2b...@kitterman.com>: ||On April 29, 2024 9:27:20 PM UTC, Steffen Nurpmeso via Postfix-users \ ||<postfix-users@postfix.org> wrote: ||>Tim Coote via Postfix-users wrote in ||> <d7c84b22-180c-4e2f-bd0b-3bb5c7d29...@coote.org>: | ... ||>|That’s why I formed a hypothesis that (my) Postfix had changed this \ ||>|long header - as you note this is < 998 stmp limit. I presume it’s \ ||>|not directly involved now, as smtp_line_length_limit is the default \ ||>|(998) | ... ||>Note that in practice only exim and the DKIM library it uses (from ||>2009) produce really standard-conforming results, all other ||>implementations i have tested have some edge cases. For example, ||>opendkim and rspamd (as of git) use (at least in pars, or always) ||>the C function isspace(3) to normalize whitespace, which is not ||>allowed according to the DKIM RFC. They all do it wrong. The ||>most minimum and in practice very likely non-failing (or not at ||>all) is dkimpy (which uses the python function trim(), but only as ||>the very last step). My upcoming sign-only milter will only ||>support relaxed/relaxed, but is hard-conforming, too. || ||If you have examples of cases where dkimpy is wrong, please file bugs \ ||or email me off list. It aims to support the RFC requirements with \ ||only minimal tweaks for interoperability. | |I did not want to insult you! |In mind i had these canon..py snippets | | def strip_trailing_whitespace(content): | return re.sub(b"[\t ]+\r\n", b"\r\n", content) | | | def compress_whitespace(content): | return re.sub(b"[\t ]+", b" ", content) | | ... | | (x[0].lower().rstrip(), | compress_whitespace(unfold_header_value(x[1])).strip() + b"\r\n") | for x in headers] | |These strip()s remove any whitespace, as opposed to [\t ] only.
In general "all the interoperability problems" are only (as far as *i* flew above it) about such whitespace issues. Most dramatical, still, by opendkim and rspamd (git repository source). --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt) _______________________________________________ Postfix-users mailing list -- postfix-users@postfix.org To unsubscribe send an email to postfix-users-le...@postfix.org
