Right now we can take the digests only of an RSA key, and only expect to
take the digests of an RSA key. The old tor_cert_get_id_digests() would
return a good set of digests for an RSA key, and an all-zero one for a
non-RSA key. This behavior is too error-prone: it carries the risk that
we will someday check two non-RSA keys for equality and conclude that
they must be equal because they both have the same (zero) "digest".
Instead, let's have tor_cert_get_id_digests() return NULL for keys we
can't handle, and make its callers explicitly test for NULL.
Our keys and x.509 certs are proliferating here. Previously we had:
An ID cert (using the main ID key), self-signed
A link cert (using a shorter-term link key), signed by the ID key
Once proposal 176 and 179 are done, we will also have:
Optionally, a presentation cert (using the link key),
signed by whomever.
An authentication cert (using a shorter-term ID key), signed by
the ID key.
These new keys are managed as part of the tls context infrastructure,
since you want to rotate them under exactly the same circumstances,
and since they need X509 certificates.
Also remove a few other related warnings that could occur during the ssl
handshake. We do this because the relay operator can't do anything about
them, and they aren't their fault.
- We were reporting the _bottom_ N failing states, not the top N.
- With bufferevents enabled, we logged all TLS states as being "in
bufferevent", which isn't actually informative.
- When we had nothing to report, we reported nothing too loudly.
- Also, we needed documentation.
This code lets us record the state of any outgoing OR connection
that fails before it becomes open, so we can notice if they're all
dying in the same SSL state or the same OR handshake state.
More work is still needed:
- We need documentation
- We need to actually call the code that reports the failure when
we realize that we're having a hard time connecting out or
making circuits.
- We need to periodically clear out all this data -- perhaps,
whenever we build a circuit successfully?
- We'll eventually want to expose it to controllers, perhaps.
Partial implementation of feature 3116.
SSL_*_app_data uses ex_data index 0, which will be the first one allocated
by SSL_get_ex_new_index. Thus, if we ever started using the ex_data feature
for some other purpose, or a library linked to Tor ever started using
OpenSSL's ex_data feature, Tor would break in spectacular and mysterious
ways. Using the SSL_*_ex_data functions directly now may save us from
that particular form of breakage in the future.
But I would not be surprised if using OpenSSL's ex_data functions at all
(directly or not) comes back to bite us on our backends quite hard. The
specified behaviour of dup_func in the man page is stupid, and
crypto/ex_data.c is a horrific mess.
Our regular DH parameters that we use for circuit and rendezvous
crypto are unchanged. This is yet another small step on the path of
protocol fingerprinting resistance.
We need filtering bufferevent_openssl so that we can wrap around
IOCP bufferevents on Windows. This patch adds a temporary option to
turn on filtering mode, so that we can test it out on non-IOCP
systems to make sure it hasn't got any surprising bugs.
It also fixes some allocation/teardown errors in using
bufferevent_openssl as a filter.
First start of a fix for bug2001, but my test network still isn't
working: the client and the server send each other VERSIONS cells,
but never notice that they got them.
* Make tor_tls_context_new internal to tortls.c, and return the new
tor_tls_context_t from it.
* Add a public tor_tls_context_init wrapper function to replace it.
