turns out that some IMAP servers (e.g., poczta.o2.pl) do not return
messages in ascending UID order in response to a UID FETCH request,
which makes the driver violate the API contract.
counter this by sorting the messages. this also addresses the
long-standing (but hypothetical) issue that parallel UID FETCH requests
could be handled out-of-order and thus also lead to mixed up results.
based on patch by Marcin Niestroj <macius1990w@gmail.com>.
while only 1KiB is required by the IMAP spec, AUTHENTICATE GSSAPI with
Kerberos requires about 1700 bytes.
accomodate that, plus some reserve.
fix suggested by Tollef Fog Heen <tfheen@err.no> via Debian BTS.
there is no reason not to, and debian even disabled 1.0 globally,
because it's (theoretically) too insecure in some contexts (BEAST
attack).
in the compat wrapper, the UseTLSv1 option has been re-interpreted as
v1.x, to avoid adding new options.
the only legitimate "deviant" UID is zero, meaning "no message". this
can be futher qualified by additional flags in the sync record, rather
than using magic values for the UID. in fact, the zero UID (so far
meaning only "expunged") was already optionally qualifed with "expired".
as a side effect, driver->store_msg() now returns 0 instead of -2 for
unknown UIDs. this was a hack to avoid translating the value later
on, but it made the api horrible, and now it's superflous in the first
place.
do that by wrapping the actual stores into proxies.
the proxy driver's code is auto-generated from function templates, some
parameters, and the declarations of the driver functions themselves.
attempts to do it with CPP macros turned out to be a nightmare.
if the server sends no UIDNEXT, do an initial FETCH to query the UID of
the last message.
same if the server sends no APPENDUID.
this allows us to remove the arbitrary limitation of the UID range to
INT_MAX, at the cost of additional round-trips.
multiple Channels can call driver_t::list_store() with different LIST_*
flags. assuming the flags are actually taken into consideration, using a
single boolean 'listed' flag to track whether the Store still needs to
be listed obviously wouldn't cut it - if INBOX does not live right under
Path and the Channels used entirely disjoint Patterns (say, * and
INBOX*), the second Channel in a single run (probably a Group) would
fail to match anything.
to fix this, make store_t::listed more granular. this also requires
moving its handling back into the drivers (thus reverting c66afdc0),
because the actually performed queries and their possible implicit
results are driver-specific.
note that this slightly pessimizes some cases - e.g., an IMAP Store with
Path "" will now list the entire namespace even if there is only one
Channel with Pattern "INBOX*" (because a hypothetical Pattern "*" would
also include INBOX*, and the queries are kept disjoint to avoid the need
for de-duplication). this isn't expected to be a problem, as listing
mailboxes is generally cheap.
latest since 77acc268, the code prior to these statements ensures that
the full length is available, so just use memcpy(). the code for
comparing TUIDs uses memcmp() anyway.
when syncing flags but not re-newing non-fetched messages, there is no
need to query the message size for all messages, as the old ones are
queried only for their flags.
instead of a single hard-coded branch, use a generic method to split
ranges as needed.
this is of course entirely over-engineered as of now, but subsequent
commits will make good use of it.
if AuthMechs includes more than just LOGIN and the server announces any
AUTH= mechanism, we try SASL. but that can still fail to find any
suitable authentication mechanism, and we must not error out in that
case if we are supposed to fall back to LOGIN.
specifically, if AuthMechs included more than just LOGIN (which would be
the case for '*') and the server announced any AUTH= mechanism, we'd
immediately error out upon seeing it, thus failing to actually try
LOGIN.
the number was chosen to make queries more comprehensible when the
server sends no UIDNEXT, but it appears that such insanely large UIDs
actually show up in the wild. so send 32-bit INT_MAX instead.
note that this is again making an assumption: that no server uses
unsigned ints for UIDs. but we can't sent UINT_MAX, as that would break
with servers which use signed ints. also, *we* use signed ints (which is
actually a clear violation of the spec).
it would be possible to special-case the range [1,inf] to 1:*, thus
entirely removing arbitrary limits. however, when the range doesn't
start at 1, we may actually get a single message instead of none due to
the imap uid range limits being unordered. this gets really nasty when
we need to issue multiple queries, as we may list the same message
twice.
a reliable way around this would be issuing a separate query to find the
actual value of UID '*', to make up for the server not sending UIDNEXT
in the first place. this would obviously imply an additional round-trip
per mailbox ...
it is legal for an email system to simply change the case of rfc2822
headers, and at least one imap server apparently does just that.
this would lead to us not finding our own header, which is obviously not
helpful.
REFMAIL: CA+fD2U3hJEszmvwBsXEpTsaWgJ2Dh373mCESM3M0kg3ZwAYjaw@mail.gmail.com
Oswald Buddenhagen
Alessandro Ghedini
Anton Khirnov