While we support initializing records via coercion from an expression
list, e.g.,
local x: X = [$x1=1, $x2=2];
this can sometimes obscure the code to readers, e.g., when assigning to
value declared and typed elsewhere. The language runtime has a similar
overhead since instead of just constructing a known type it needs to
check at runtime that the coercion from the expression list is valid;
this can be slower than just writing the readible code in the first
place, see #4559.
With this patch we use explicit construction, e.g.,
local x = X($x1=1, $x2=2);
This PR changes the way in which the SSL analyzer tracks the direction
of connections. So far, the SSL analyzer assumed that the originator of
a connection would send the client hello (and other associated
client-side events), and that the responder would be the SSL servers.
In some circumstances this is not true, and the initiator of a
connection is the server, with the responder being the client. So far
this confused some of the internal statekeeping logic and could lead to
mis-parsing of extensions.
This reversal of roles can happen in DTLS, if a connection uses STUN -
and potentially in some StartTLS protocols.
This PR tracks the direction of a TLS connection using the hello
request, client hello and server hello handshake messages. Furthermore,
it changes the SSL events from providing is_orig to providing is_client,
where is_client is true for the client_side of a connection. Since the
argument positioning in the event has not changed, old scripts will
continue to work seamlessly - the new semantics are what everyone
writing SSL scripts will have expected in any case.
There is a new event that is raised when a connection is flipped. A
weird is raised if a flip happens repeatedly.
Addresses GH-2198.
This addresses feedback to GH-1814. The most significant change is the
fact that the ChipertextRecord now can remain &transient - which might
lead to improved speed.
This commit refactors TLS decryption, adds more comments in scripts and
in C++ source-code, and removes use of bare pointers, instead relying
more on stl data types.
- make TLS12 PRF a member function of the analyzer
- use std::string in PRF
- use StringValPtr instead of zeek::StringVal
- replace malloc/free with C++ style allocations
Several limitations still apply:
- TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 is the only supported cipher suite
- Some tests are broken due to a failing assertion regarding bytestring
- No newly written tests for decryption (the patch was tested extensively for our paper)
- Several small open technical questions marked with FIXME
- Architecture in the ssl module might not be optimal
