properly distribute the certificates between the SSL context's trust
store and our host cert list.
as a drive-by, clean up some nasty type casts at the cost of including
a second OpenSSL header into socket.h.
... by making a lot of objects unsigned, and some signed.
casts which lose precision and change the sign in one go (ssize_t and
time_t to uint on LP64) are made explicit as well.
this is actually potentially counterproductive, as people who have set
SSLVersions and fail to adjust it will _lose_ tls 1.3 support. however,
without the option being there, people (incorrectly) believe that tls
1.3 is not supported.
Some distributions (e.g. Fedora) added support for system wide crypto
policies. This is supported in most common crypto libraries including
OpenSSL. Applications can override this policy using their own cipher
string. This commit adds support for specifying the cipher string in
the mbsync configuration.
For example, to exclude Diffie-Hellman, the user can specify
CipherString "DEFAULT:!DH"
in the IMAP Account's configuration.
the operator was exactly inverted. that means that it actually wouldn't
compile with both older versions (that needed the aliases) and
potentially new versions (that will hide the data members - still not
the case as of 3.2).
amends 8a40554f0.
we need to deep-copy the struct hostent data, as otherwise the
concurrent connects will overwrite each other's lookup results.
this is a rather hypothetical fix, as the bug currently affects only
channels connecting two IMAP accounts, and only if the first host's
first address asynchronously fails to connect.
we did already set up the timeout when starting to send commands, but so
far we did not reset it when succeeding to send out data. rectify that.
REFFAIL: 87sgy92we3.fsf@jnanam.net
while that's just bad api, inflate() can return Z_BUF_ERROR during
normal operation.
contrary to the zpipe example and what the documentation implies,
deflate() actually isn't that braindead. add respective comments.
REFMAIL: CALA3aExMjtRL0tAmgUANpDTnn-_HJ0sYkOEXWzoO6DVaiNFUHQ@mail.gmail.com
The `socket_connect_one` function previously did an `exit(1)` when
encountering any errors with opening the socket. This would break
connecting to a host where multiple possible addrinfos are returned,
where the leading addrinfos are in fact impossible to connect to. E.g.
with a kernel configured without support for IPv6, the `getaddrinfo`
call may still return a hint containing an IPv6 address alongside
another hint with an IPv4 address. Creating the socket with the IPv6
address, which will cause an error, lead us to exiting early without
even trying remaining hints.
While one can argue that the user should have compiled without HAVE_IPV6
or used an appropriate DNS configuration, we can do better by simply
skipping over the current addrinfo causing an error. To do so, we split
out a new function `socket_connect_next`, which selects the next
available address info and subsequently calls `socket_connect_one`
again. When no hints remain, `sock_connect_one` will error out at that
point.
any structures may be invalid after callback invocation.
this has the side effect that the socket write callback now returns
void, like all other callbacks do.
the synchronous writing to the socket would have typically invoked the
write callback, which would flush further commands, thus recursing.
we take the easy way out and make it fully asynchronous, i.e., no data
is sent before (re-)entering the event loop.
this also has the effect that socket_write() cannot fail any more, and
any errors will be reported asynchronously. this is consistent with
socket_read(), and produces cleaner code.
this introduces a marginal performance regression: the maildir driver is
synchronous, so all messages (which fit into memory) will be read before
any data is sent. this is not considered relevant.
propagating many messages from a fast store (typically maildir or a
local IMAP server) to a slow asynchronous store could cause gigabytes of
data being buffered. avoid this by throttling fetches if the target
context reports memory usage above a configurable limit.
REFMAIL: 9737edb14457c71af4ed156c1be0ae59@mpcjanssen.nl
some servers actually bother to close down the SSL connection before
closing the socket.
this fixes the spurious "unhandled SSL error 6" messages.
REFMAIL: 20150120114805.GA17586@leeloo.kyriasis.com
the server can actually close the zlib stream before closing the socket,
so we need to accept it.
we don't do anything beyond that - the actual EOF will be signaled by
the socket, and if the server (erroneously) sends more data, zlib will
tell us about it.
REFMAIL: 1423048708-975-1-git-send-email-alex.bennee@linaro.org
zlib reports Z_BUF_ERROR when a flush is attempted without any activity
since the previous flush (if any). while this is harmless as such,
discerning the condition from genuine errors would be much harder than
avoiding the pointless flush in the first place.
REFMAIL: eb5681612f17be777bc8d138d31dd6d6@mpcjanssen.nl
the primary objective is reducing the number of small SSL packets (which
are always padded), but fewer syscalls in the non-SSL case should be
good as well.
