The way in which TLS 1.3 is negotiated was changed slightly in later
revisions of the standard. The final version is only sent in an
extension - while the version field in the server hello still shows TLS
1.2.
This patch makes ssl.log show the correct version again.
Now we only parse the SignatureAndHashalgorithm field in cases where it
is present. This change also takes care to respect SCTs, which do
include the SignatureAndHashalgorithm in their digitally-signed struct,
even when used in protocol versions that do not have the
SignatureAndHashalgorithm in the protocols digitally-signed struct.
I also added tests to make sure this does indeed work with TLS 1.1 - it
turns out that so far we did not have a single TLS 1.1 pcap.
This commit fixes a few small issues.
* server key exchange parameters are only parsed when a named curve is
given.
* I removed the ssl-verbose.bro and moved the functionality into the
testcase.
The information that we get with these events is likely irrelevant to
the majority of Bro users; I do not think that we have to ship a
script that uses them by default. A script like this would be
something to publish via the Bro package manager instead; this is the
approach that we have taken with a number of the recent SSL addition.
* I marked the ssl_server_curve event as deprecated. More information is
contained in the new ssl_ecdh_server_params event.
This is an events that is probably seldomly (or never) directly used
by anyone; I plan to completely remove it right after the 2.6 release.
It turns out that Chrome supports an experimental mode to support TLS
1.3, which uses a non-standard way to negotiate TLS 1.3 with a server.
This non-standard way to negotiate TLS 1.3 breaks the current draft RFC
and re-uses an extension on the server-side with a different binary
formatting, causing us to throw a binpac exception.
This patch ignores the extension when sent by the server, continuing to
correctly parse the server_hello reply (as far as possible).
From what I can tell this seems to be google working around the fact
that MITM equipment cannot deal with TLS 1.3 server hellos; this change
makes the fact that TLS 1.3 is used completely opaque unless one looks
into a few extensions.
We currently log this as TLS 1.2.
The dpd signature missed a few cases that are used for TLS 1.3,
especially when draft versions (which are all that we are seeing at the
moment) are being negotiated.
This fix mostly allows draft versions in the server hello (identified by
7F[version]; since we do not know how many drafts there will be, we are
currently allowing a rather safe upper limit.
This does not yet work for certificates, because this requires some
changing the ASN.1 structure before validation (we need to extract the
tbscert and remove the SCT extension before).
API will change in the future.
This commit add the table SSL::ct_logs to Bro. This table is populated
with information about the currently active certificate transparency
logs (data from Google). The data can, e.g., be used to identify which
Logs are being used in SCTs.
Re-enable logging, now in policy because it probably is interesting to
no-one. We also only log ocsp replies.
Fix all tests.
Fix an issue where ocsp replies were added to the x.509 certificate
list.
Now the DTLS analyzer cleanly skips all STUN messages; no warnings
should be logged to dpd.log and parsing should work flawlessly with
intermixed STUN messages.
The alert in this case is caused by the server name in the SNI not being
recognized by the server, which triggers an alert. Since the server is
an apache, and this might happen reasonably often, the new signature
allows one TLS alert before the server hello is expected.
This also patches a few tests to contain certificates that were removed.
Furthermore, we include the old CA file with the external tests and load
it automatically. Those traces are kind of old now, more and more of the
CAs in them are no longer valid and it does not really make sense to
update them on each change...
The only thing that is missing is a signature to detect the protocol (it
has no well-known port).
Reassembly is kind of fidgety - at the moment we only support
re-assembling one simultaneous message per direction (which looking at
our test-traffic might not be a problem). And I am not quite sure if I
got all cases correct...
But - it works :)
triggered for the tls change cipherspec message.
Also - fix small bug. In case SSL::disable_analyzer_after_detection was set
to F, the ssl_established event would fire after each data packet after the
session is established.
This also fixes the heartbleed detector to work for encrypted attacks in this
branch again. It stopped working, because the SSL analyzer now successfully detects
established connections, and the scripts usually disable analyzing after that.
(The heartbeat branch should not have been affected)
That means that, for example, connections that are terminated with an alert during the
handshake never appear in the ssl.log.
This patch changes this behavior - now all ssl connections that fire any event are logged.
The protocol confirmation of the ssl analyzer is moved to the client_hello instead to
the server hello. Furthermore, an additional field is added to ssl.log, which indicates
if a connection has been established or not (which probably indicates a handshake problem).
The event now really returns the extension. If openssl supports printing
it, it is converted into the openssl ascii output.
The output does not always look pretty because it can contain newlines.
New event syntax:
event x509_extension(c: connection, is_orig: bool, cert:X509, extension: X509_extension_info)
Example output for extension:
[name=X509v3 Extended Key Usage,
short_name=extendedKeyUsage,
oid=2.5.29.37,
critical=F,
value=TLS Web Server Authentication, TLS Web Client Authentication]
[name=X509v3 Certificate Policies,
short_name=certificatePolicies,
oid=2.5.29.32,
critical=F,
value=Policy: 1.3.6.1.4.1.6449.1.2.1.3.4^J CPS: https://secure.comodo.com/CPS^J]
- Thanks for help from Rafal Lesniak in nailing down the location
of the bug and supplying test traffic.
- Test traffic with a TLS 1.2 connection.
- Addresses ticket #1020
- SSL related files and classes renamed to remove the "binpac" term.
- A small fix for DPD scripts to make the DPD log more helpful if
there are multiple continued failures. Also, fixed the SSL
analyzer to make it stop doing repeated violation messages for
some handshake failures.
- Added a $issuer_subject to the SSL log.
- Created a basic test for SSL.
