and add an alerting rule if the failure rate becomes >10% (e.g. expired
certificate).
the prometheus metrics includes a reason, including potential tls alerts, if
remote smtp clients would send those (openssl s_client -starttls does).
inspired by issue #237, where incoming connections were aborted by remote. such
errors would show up as "eof" in the metrics.
all ui frontend code is now in typescript. we no longer need jshint, and we
build the frontend code during "make build".
this also changes tlsrpt types for a Report, not encoding field names with
dashes, but to keep them valid identifiers in javascript. this makes it more
conveniently to work with in the frontend, and works around a sherpats
limitation.
we don't want external software to include internal details like mlog.
slog.Logger is/will be the standard.
we still have mlog for its helper functions, and its handler that logs in
concise logfmt used by mox.
packages that are not meant for reuse still pass around mlog.Log for
convenience.
we use golang.org/x/exp/slog because we also support the previous Go toolchain
version. with the next Go release, we'll switch to the builtin slog.
- dmarc reports: add a cid to the log line about one run of sending reports, and log line for each report
- in smtpclient, also handle tls errors from the first read after a handshake. we appear to sometimes get tls alerts about bad certificates on the first read.
- for messages to dmarc/tls reporting addresses that we think should/can not be processed as reports, add an X-Mox- header explaining the reason.
- tls reports: send report messages with From address of postmaster at an actually configured domain for the mail host. and only send reports when dkim signing is configured for that domain. the domain is also the submitter domain. the rfc seems to require dkim-signing with an exact match with the message from and submitter.
- for incoming tls reports, in the smtp server, we do allow a dkim-signature domain that is higher-level (up to publicsuffix) of the message from domain. so we are stricter in what we send than what we receive.
we were already accepting, processing and displaying incoming tls reports. now
we start tracking TLS connection and security-policy-related errors for
outgoing message deliveries as well. we send reports once a day, to the
reporting addresses specified in TLSRPT records (rua) of a policy domain. these
reports are about MTA-STS policies and/or DANE policies, and about
STARTTLS-related failures.
sending reports is enabled by default, but can be disabled through setting
NoOutgoingTLSReports in mox.conf.
only at the end of the implementation process came the realization that the
TLSRPT policy domain for DANE (MX) hosts are separate from the TLSRPT policy
for the recipient domain, and that MTA-STS and DANE TLS/policy results are
typically delivered in separate reports. so MX hosts need their own TLSRPT
policies.
config for the per-host TLSRPT policy should be added to mox.conf for existing
installs, in field HostTLSRPT. it is automatically configured by quickstart for
new installs. with a HostTLSRPT config, the "dns records" and "dns check" admin
pages now suggest the per-host TLSRPT record. by creating that record, you're
requesting TLS reports about your MX host.
gathering all the TLS/policy results is somewhat tricky. the tentacles go
throughout the code. the positive result is that the TLS/policy-related code
had to be cleaned up a bit. for example, the smtpclient TLS modes now reflect
reality better, with independent settings about whether PKIX and/or DANE
verification has to be done, and/or whether verification errors have to be
ignored (e.g. for tls-required: no header). also, cached mtasts policies of
mode "none" are now cleaned up once the MTA-STS DNS record goes away.
