This resolves a medium vulnerability described in the
Beast Hybrid Assessment Report by Bishop Fox, where masks generated
for use with outgoing WebSocket client frames use an insufficient
source of entropy and a non-cryptographically secure pseudo-random
number generator.
By default, all newly constructed WebSocket streams will use a
uniquely seeded secure PRNG (ChaCha20 in counter mode). As this may
result in increased CPU resource consumption, the function
websocket::stream::secure_prng() may be used to select a faster but
less secure PRNG, for the case where the caller knows that the secure
generator is not necessary.
On some systems, std::random_device may produce insufficient entropy
to securely seed the PRNG. As this condition cannot be detected by
Beast, callers may use the function websocket::seed_prng() called
once at startup to provide at least 256 bits of entropy which will
be used to uniquely seed all subsequent PRNGs.
The ssl_stream wrapper provides C++11 move semantics for ssl::stream,
as well as incorporating the flat_stream workaround for a performance
problem with ssl::stream writes and buffer sequences having length
greater than one.
fix#1108
The `flat_stream` is a stream wrapper designed to overcome a
performance limitation of the `boost::asio::ssl::stream`
implementation. Specifically, when writing buffer sequences having
length greater than one, the `ssl::stream` implementation does
not use scatter-gather I/O and instead performs a kernel transition
for every buffer in the sequence.
The wrapper addresses this problem by allocating memory and
presenting the buffer sequence into a single buffer, using
some logic to determine when this allocation is advantageous
versus simply passing the buffers through as-is.
See Also:
https://github.com/boostorg/asio/issues/100https://stackoverflow.com/questions/50026167/performance-drop-on-port-from-beast-1-0-0-b66-to-boost-1-67-0-beast
fix#1076
As per Asio and Networking TS requirements, composed operations must
maintain an object of type executor_work_guard for the executor associated
with the I/O object, for the lifetime of the asynchronous operation.
This is in addition to the requirement for maintaining an object of type
executor_work_guard for the executor associated with the handler.
fix#941, fix#1016
`get_lowest_layer` is now a type alias for the
lowest layer instead of a struct with a nested type.
Actions required:
* Replace instances of `typename get_lowest_layer<T>::type`
with `get_lowest_layer<T>`.
fix#949
* New error codes are introduced for WebSocket failures
* More verbose messages for error codes
* Error codes are mapped to conditions for ease of testing
* error::failed and error::handshake_failed are deprecated (don't use)
Actions Required:
* Code which explicitly compares error_code values against the
constant `websocket::error::handshake_failed` should compare
against `websocket::condition::handshake_failed` instead.
* Code which explicitly compares error_code values against the
constant `websocket::error::failed` should compare
against `websocket::condition::protocol_violation` instead.
fix#849
This adds an additional `bool` template parameter to
`websocket::stream`:
* When deflateSupported is `true`, the stream will be capable
of negotiating the permessage-deflate websocket extension per
the configured run-time settings.
* When deflateSupported is `false`, the stream will never negotiate
the permessage-deflate websocket extension. Furthermore, all of the
code necessary for implementing the permessage-deflate extension
will be excluded from function instantiations. The resulting emitted
object code should be smaller.
fix#884
* BodyReader and BodyWriter constructors now require the header and
body elements to be passed as distinct header and value_type objects.
This enables the composition of body types, for example:
http::response<compressed_body<http::string_body>> res;
* The previous single-argument constructors are deprecated and will be
removed in a subsequent version.
Actions Required:
* Change user-defined instances of BodyReader or BodyWriter constructor
signatures to the two-argument form.
OR
* Define the macro BOOST_BEAST_ALLOW_DEPRECATED in the project (which
will accept both the new and the deprecated signatures).
compmaniak
felixguendling
Vinnie Falco
Ivan Vilata-i-Balaguer
Damian Jarek
p-kalugin