This change introduces a demux that uses the kernel's network stack for UDP
datagram-to-socket assignment based on packet source address (as opposed to the
forwarding strategy of the routing demux). The osnet demux is used by default
on non-Windows platforms. When possible, use of the osnet demux is preferred
over the routing demux, since it can be expected to perform better.
The unit test suite has been extended to run all tests first with the demux
selected by default for the current platform, and then with the routing demux,
if the latter differs from the former. Tests were already being run twice, first
with IPv4 and then with IPv6, and thus we now run each test four times on
Linux, twice on Windows.
All unit tests pass with both demux types.
With this change all unit tests pass on the Linux platform (tested on
Ubuntu 12.04.1 LTS). demux/__init__.py has been adjusted temporarily so as
to load the routing demux on Linux until the osnet demux is ready.
Testing on Linux exposed an issue where comparison of the ssl object value from
cookie callbacks failed to compare equal to the value stored in the
SSLConnection callback object. This was because the callback function signature
of c_void_p for this parameter produced a 64-bit value if the 32nd bit was set
(as opposed to producing a negative integer 32-bit value). Changing the
signature from c_void_p to c_int for this parameter fixes the issue.
This initial commit for the PyDTLS package includes the following functionality:
* DTLS cookie exchange, using secure hmac cookies
* A platform-independent routing UDP demultiplexer
* SSL handshaking over UDP using the DTLS protocol
* Datagram exchange using the DTLS protocol
* SSL shutdown over UDP
The package is structured as follows:
* dtls: top-level package
* dtls.demux: demultiplexer package; automatically loads a
demultiplexer appropriate for the currently executing
platform
* dtls.demux.router: a routing demux for platforms whose network stacks
cannot assign incoming UDP packets to sockets based
on the sockets' connection information
* dtls.demux.osnet: a demux that uses the operating system's UDP packet
routing functionality
* dtls.err: package-wide error handling and error definitions
* dtls.sslconnection: a client and server-side connection class for
UDP network connections secured with the DTLS protocol
* dtls.openssl: a ctypes-based wrapper for the OpenSSL library
* dtls.test: test scripts, utilities, and unit tests
The following binaries are provided:
* libeay32.dll: cryptographic portion of the OpenSSL library
* ssleay32.dll: protocol portion of the OpenSSL library (depends on former)
* cygcrypto-1.0.0.dll: as libeay32.dll, but with debugging symbols
* cygssl-1.0.0.dll: as ssleay32.dll, but with debugging symbols
All binaries have been built with the MinGW tool chain, targeted for msvcr90.
The unstripped dll's can be debugged on Windows with gdb. Cygwin is not used.
Ray Brown