ihasmail runs in its own container, usually on its own host, so Stalwart being
briefly unreachable is an ordinary Tuesday. Sign-in handled it almost right:
a 401 is invalid_credentials, a timeout is 504 and anything else is 502, none
of which reads as a rejected password.
What it got wrong was the counting. RateLimiter.check() consumes an attempt
when it is called, and it is called before the upstream is contacted; reset()
only runs on success. So every try against an unreachable server burned a
credential attempt, and after ten of them the person was locked out for the
rest of the fifteen-minute window -- including after the server came back. A
thirty-second blip became a quarter-hour lockout, and the second failure was
entirely ihasmail's own doing.
A 401 is a judgement about the password and stays counted. A 502 or 504 is the
upstream failing to answer, says nothing about the credentials, and is now
refunded -- one attempt back, not the key cleared, so a run of real failures
with an outage in the middle still adds up. The old-server refusal refunds too:
those credentials were accepted.
Both guessing keys are refunded, not just the username one. Refunding only
that would not have fixed it -- ten retries still spend the per-address budget,
and behind one office NAT that budget belongs to the whole building, so a
company-wide outage would lock out the company.
Which needs a backstop, because "not counted" must not mean "unlimited": each
attempt still costs an outbound connection that may sit there until
UPSTREAM_TIMEOUT, and an outage is the one moment the endpoint is cheapest to
abuse. So there is a second ceiling per address, twenty times looser and never
refunded. A person retrying will not come near it; something hammering will.
Both messages now say the quiet part -- "This is not a problem with your
password" -- for somebody already worried they have forgotten it.
Closes#239.
A .md previewed as its own source, which is reading the punctuation
rather than the notes. It now opens rendered, with Rendered | Source in
the dialog footer for anyone who wants what the file actually says.
Markdown only; a .txt has nothing to toggle between.
Rendering is `marked`, sanitised by DOMPurify -- the one the app already
carries for mail. Markdown is not a safe subset of anything: raw HTML
passes through it by design, so a <script> in a file somebody uploaded or
shared into the account is a script tag unless something takes it out.
Images become links rather than pictures. An image in a Markdown file is
either a relative path, which has no base to resolve against here, or a
URL somewhere else, which fetches on open and tells that server the file
was read -- the tracking pixel this app blocks in mail. The link keeps
the alt text and the address, so nothing vanishes silently.
Fixes the PDF preview while here, which never worked: securityHeaders
put X-Frame-Options: DENY on every response including the blob route, so
the iframe showed Chrome's "refused to connect" where the file should
have been -- in Files today and in mail attachments long before that.
The middleware now leaves a header the route has set, and a PDF served
inline says SAMEORIGIN. Nothing else on the server is framable.
A gzip response is decompressed before the blob proxy sees the body, but
its content-length still describes the compressed bytes. Copying that
header onto the longer body made the browser stop reading that many bytes
in and call the download complete, so files arrived truncated with nothing
reporting a failure.
It took a hop that compresses to show up, and one that only compresses
above a threshold to look like a race: a Sieve script stayed intact for two
rules and came back cut off mid-rule once the third pushed it past 1 KiB.
Ask upstream for identity, and forward no length at all rather than one
that describes different bytes.
jcoffey-dev