From c41f94b0f5c9ff2f56eae628b30d5b59f785481e Mon Sep 17 00:00:00 2001 From: Konstantin Ryabitsev Date: Thu, 10 Dec 2020 17:09:55 -0500 Subject: DKIM: remove extra public-inbox headers The reason alsa-devel DKIM verification is failing is because the List-Archive header is included in the hashed value. This header is added by public-inbox to all messages retrieved via the API, so try ejecting those headers and retrying verification. Link: https://public-inbox.org/meta/20201210202145.7agtcmrtl5jec42d@chatter.i7.local Signed-off-by: Konstantin Ryabitsev --- b4/__init__.py | 25 +++++++++++++++++++++++++ 1 file changed, 25 insertions(+) diff --git a/b4/__init__.py b/b4/__init__.py index 4270b40..fecd9aa 100644 --- a/b4/__init__.py +++ b/b4/__init__.py @@ -1691,6 +1691,7 @@ class LoreAttestationSignatureDKIM(LoreAttestationSignature): # self.native_verify() # return + ejected = set() while True: dks = self.msg.get('dkim-signature') if not dks: @@ -1707,6 +1708,30 @@ class LoreAttestationSignatureDKIM(LoreAttestationSignature): else: res = dkim.verify(self.msg.as_bytes()) if not res: + # is list-archive or archived-at part of h=? + hline = ddata.get('h') + if hline: + hsigned = set(hline.lower().split(':')) + if 'list-archive' in hsigned or 'archived-at' in hsigned: + # Public-inbox inserts additional List-Archive and Archived-At headers, + # which breaks DKIM signatures if these headers are included in the hash. + # Eject the ones created by public-inbox and try again. + # XXX: This may no longer be necessary at some point if public-inbox takes care + # of this scenario automatically: + # https://public-inbox.org/meta/20201210202145.7agtcmrtl5jec42d@chatter.i7.local + logger.debug('Ejecting extra List-Archive headers and retrying') + changed = False + for header in reversed(self.msg._headers): # noqa + hl = header[0].lower() + if hl in ('list-archive', 'archived-at') and hl not in ejected: + self.msg._headers.remove(header) # noqa + ejected.add(hl) + changed = True + break + if changed: + # go for another round + continue + logger.debug('DKIM signature did NOT verify') logger.debug('Retrying with the next DKIM-Signature header, if any') at = 0 -- cgit v1.2.3