This patch adds checks that verify:
- The envelope from must match the authenticated user. This prevents
impersonation at the envelope level (while still allowing bounces, of
course).
- If the destination is remote, then the user must have completed
authentication. This prevents unauthorized relaying.
The patch ends up adjusting quite a few tests, as they were not written
considering these restrictions so they have to be changed accordingly.
We want to be able to distinguish between connections for SMTP and connections
for submission, so we can make different policy decisions.
To do that, we first make the configuration aware of the different kinds of
addresses. This is done in this patch in a backwards-incompatible way, but at
this point in time it is ok to do so.
Then, we extend systemd's socket passing library to support socket naming, so
we can tell the different sockets apart. This is done via the
LISTEN_FDNAMES/FileDescriptorName mechanism.
And finally we make the server and connection types aware of the socket mode.
This patch adds a new test which makes chasquid send and receive email to/from
Exim.
To make it work we need to add two testing flags to the SMTP courier, which is
not ideal but doesn't muddle the code much.
The test is not very portable, and assumes an exim binary is available, but
does not have to be installed in the system. It includes a helper script to
fetch one from the Debian archives.
This patch introduces a new directory, test/, which contains a simple local
end-to-end test which runs a chasquid binary and uses msmtp to send an email,
which is delivered locally.
As it's the first one, it adds a bunch of common infrastructure to simplify
writing these kinds of tests.
More end-to-end tests will follow, and it's expected that the common
infrastructure will also change significantly to accomodate their needs.
