### Motivation:
I've now found two libraries that use Netty to be vulnerable to [CWE-113: Improper Neutralization of CRLF Sequences in HTTP Headers ('HTTP Response Splitting')](https://cwe.mitre.org/data/definitions/113.html) due to using `new DefaultHttpHeaders(false)`.
Some part of me hopes that this warning will help dissuade library authors from disabling this important security check.
### Modification:
Add documentation to `DefaultHttpHeaders(boolean)` to warn about the implications of `false`.
### Result:
This improves the documentation on `DefaultHttpHeaders`.
Motivation:
Optimize the QueryStringEncoder for lower memory overhead and higher encode speed.
Modification:
Encode the space to + directly, and reuse the uriStringBuilder rather then create a new one.
Result:
Improved performance
Motivation:
When parsing HTTP headers special care needs to be taken when a whitespace is detected in the header name.
Modifications:
- Ignore whitespace when decoding response (just like before)
- Throw exception when whitespace is detected during parsing
- Add unit tests
Result:
Fixes https://github.com/netty/netty/issues/9571
Motivation:
At the current moment HttpContentEncoder handle only first value of multiple accept-encoding headers.
Modification:
Join multiple accept-encoding headers to one separated by comma.
Result:
Fixes#9553
Motivation:
Currently when HttpPostStandardRequestDecoder throws a ErrorDataDecoderException during construction we leak memory. We need to ensure all is released correctly.
Modifications:
- Call destroy() if parseBody() throws and rethrow the ErrorDataDecoderException
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9513.
Motivation:
We did not correctly pass all supplied parameters to the called constructor and so did not apply the timeout.
Modification:
Correctly pass on the parameters.
Result:
Use timeout
Motivation:
Some of the links in javadoc point to the obsolete drafts of HTTP/2
specifications. We should point them to the latest RFC 7540 or 7541.
Modifications:
Update links from `draft-ietf-httpbis-*` to the `rfc7540` and `rfc7541`.
Result:
Correct links in javadoc.
Motivation:
`HttpObjectDecoder` pre-checks that it doesn't request characters
outside of the `AppendableCharSequence`'s length. `0` is always allowed
because the minimal length of `AppendableCharSequence` is `1`. We can
legally skip index check by using
`AppendableCharSequence.charAtUnsafe(int)` in all existing cases in
`HttpObjectDecoder`.
Modifications:
- Use `AppendableCharSequence.charAtUnsafe(int)` instead of
`AppendableCharSequence.charAt(int)` in `HttpObjectDecoder`.
Result:
No unnecessary index checks in `HttpObjectDecoder`.
Motivation:
Http post request may be encoded as 'multipart/form-data' without any files and consist mixed attributes only.
Modifications:
- Do not double release attributes
- Add unit test
Result:
Code does not throw an IllegalReferenceCountException.
Motivation:
We need to ensure we replace WebSocketServerProtocolHandshakeHandler before doing the actual handshake as the handshake itself may complete directly and so forward pending bytes through the pipeline.
Modifications:
Replace the handler before doing the actual handshake.
Result:
Fixes https://github.com/netty/netty/issues/9471.
Motivation:
If all we need is the FileChannel we should better use RandomAccessFile as FileInputStream and FileOutputStream use a finalizer.
Modifications:
Replace FileInputStream and FileOutputStream with RandomAccessFile when possible.
Result:
Fixes https://github.com/netty/netty/issues/8078.
Motivation:
It was possible to produce a NPE when we for examples received more responses as requests as we did not check if the queue did not contain a method before trying to compare method names.
Modifications:
- Add extra null check
- Add unit tet
Result:
Fixes https://github.com/netty/netty/issues/9459
Motivation:
We did not correctly pass the mask parameters in all cases.
Modifications:
Correctly pass on parameters
Result:
Fixes https://github.com/netty/netty/issues/9463.
Motivation:
Allow to set the ORIGIN header value from custom headers in WebSocketClientHandshaker
Modification:
Only override header if not present already
Result:
More flexible handshaker usage
Motivation:
If the HttpUtil.getCharset method is called with an illegal charset like
"charset=!illegal!" it throws an IllegalCharsetNameException. But the javadoc
states, that defaultCharset is returned if incorrect header value. Since the
client sending the request sets the header value this should not crash.
Modification:
HttpUtil.getCharset catches the IllegalCharsetNameException and returns the
defualt value.
Result:
HttpUtil.getCharset does not throw IllegalCharsetNameException any more.
…ryWebSocketFrames
Motivation:
`Utf8FrameValidator` is always created and added to the pipeline in `WebSocketServerProtocolHandler.handlerAdded` method. However, for websocket connection with only `BinaryWebSocketFrame`'s UTF8 validator is unnecessary overhead. Adding of `Utf8FrameValidator` could be easily avoided by extending of `WebSocketDecoderConfig` with additional property.
Specification requires UTF-8 validation only for `TextWebSocketFrame`.
Modification:
Added `boolean WebSocketDecoderConfig.withUTF8Validator` that allows to avoid adding of `Utf8FrameValidator` during pipeline initialization.
Result:
Less overhead when using only `BinaryWebSocketFrame`within web socket.
Motivation:
Our QA servers are spammed with this messages:
13:57:51.560 DEBUG- Decoding WebSocket Frame opCode=1
13:57:51.560 DEBUG- Decoding WebSocket Frame length=4
I think this is too much info for debug level. It is better to move it to trace level.
Modification:
logger.debug changed to logger.trace for WebSocketFrameEncoder/Decoder
Result:
Less messages in Debug mode.
Motivation:
In many places Netty uses Unpooled.buffer(0) while should use EMPTY_BUFFER. We can't change this due to back compatibility in the constructors but can use Unpooled.EMPTY_BUFFER in some cases to ensure we not allocate at all. In others we can directly use the allocator either from the Channel / ChannelHandlerContext or the request / response.
Modification:
- Use Unpooled.EMPTY_BUFFER where possible
- Use allocator where possible
Result:
Fixes#9345 for websockets and http package
Motivation:
We need to ensure we place the encoder before the decoder when doing the websockets upgrade as the decoder may produce a close frame when protocol violations are detected.
Modifications:
- Correctly place encoder before decoder
- Add unit test
Result:
Fixes https://github.com/netty/netty/issues/9300
Motivation:
If the encoded value of a form element happens to exactly hit
the chunk limit (8096 bytes), the post request encoder will
throw a NullPointerException.
Modifications:
Catch the null case and return.
Result:
No NPE.
Motivation:
While fixing #9359 found few places that could be patched / improved separately.
Modification:
On handshake response generation - throw exception before allocating response objects if request is invalid.
Result:
No more leaks when exception is thrown.
Motivation:
Based on https://tools.ietf.org/html/rfc6455#section-1.3 - for non-browser
clients, Origin header field may be sent if it makes sense in the context of those clients.
Modification:
Replace Sec-WebSocket-Origin to Origin
Result:
Fixes#9134 .
Motivation:
Netty homepage(netty.io) serves both "http" and "https".
It's recommended to use https than http.
Modification:
I changed from "http://netty.io" to "https://netty.io"
Result:
No effects.
Motivation:
There are is some unnecessary code (like toString() calls) which can be cleaned up.
Modifications:
- Remove not needed toString() calls
- Simplify subString(...) calls
- Remove some explicit casts when not needed.
Result:
Cleaner code
Motivation:
asList should only be used if there are multiple elements.
Modification:
Call to asList with only one argument could be replaced with singletonList
Result:
Cleaner code and a bit of memory savings
Motivation:
The HttpPostRequestEncoder overwrites the original filename of file uploads sharing the same name encoded in mixed mode when it rewrites the multipart body header of the previous file. The original filename should be preserved instead.
Modifications:
Change the HttpPostRequestEncoder to reuse the correct filename when the encoder switches to mixed mode. The original test is incorrect and has been modified too, in addition it tests with an extra file upload since the current test was not testing the continuation of a mixed mode.
Result:
The HttpPostRequestEncoder will preserve the original filename of the first fileupload when switching to mixed mode
Motivation:
I need to control WebSockets inbound flow manually, when autoRead=false
Modification:
Add missed ctx.read() call into WebSocketProtocolHandler, where read request has been swallowed.
Result:
Fixes#9257
Motivation:
Incorrect WebSockets closure affects our production system.
Enforced 'close socket on any protocol violation' prevents our custom termination sequence from execution.
Huge number of parameters is a nightmare both in usage and in support (decoders configuration).
Modification:
Fix violations handling - send proper response codes.
Fix for messages leak.
Introduce decoder's option to disable default behavior (send close frame) on protocol violations.
Encapsulate WebSocket response codes - WebSocketCloseStatus.
Encapsulate decoder's configuration into a separate class - WebSocketDecoderConfig.
Result:
Fixes#8295.
Motivation:
When connecting through an HTTP proxy over clear HTTP, user agents must send requests with an absolute url. This hold true for WebSocket Upgrade request.
WebSocketClientHandshaker and subclasses currently always send requests with a relative url, which causes proxies to crash as request is malformed.
Modification:
Introduce a new parameter `absoluteUpgradeUrl` and expose it in constructors and WebSocketClientHandshakerFactory.
Result:
It's now possible to configure WebSocketClientHandshaker so it works properly with HTTP proxies over clear HTTP.
delete Other "Content-" MIME Header Fields exception
Motivation:
RFC7578 4.8. Other "Content-" Header Fields
The multipart/form-data media type does not support any MIME header
fields in parts other than Content-Type, Content-Disposition, and (in
limited circumstances) Content-Transfer-Encoding. Other header
fields MUST NOT be included and MUST be ignored.
Modification:
Ignore other Content types.
Result:
Other "Content-" Header Fields should be ignored no exception
Motivation:
f17bfd0f64 removed the usage of static exception instances to reduce the risk of OOME due addSupressed calls. We should do the same for exceptions used to signal handshake timeouts.
Modifications:
Do not use static instances
Result:
No risk of OOME due addSuppressed calls
Motivation:
The first final version of GraalVM was released which deprecated some flags. We should use the new ones.
Modifications:
Removes the use of deprecated GraalVM native-image flags
Adds a flag to initialize netty at build time.
Result:
Do not use deprecated flags
Motivation:
Support handshake timeout option in websocket handlers. It makes sense to limit the time we need to move from `HANDSHAKE_ISSUED` to `HANDSHAKE_COMPLETE` states when upgrading to WebSockets
Modification:
- Add `handshakeTimeoutMillis` option in `WebSocketClientProtocolHandshakeHandler` and `WebSocketServerProtocolHandshakeHandler`.
- Schedule a timeout task, the task will trigger user event `HANDSHAKE_TIMEOUT` if the handshake timed out.
Result:
Fixes issue https://github.com/netty/netty/issues/8841
Motivation
Pipeline handlers are free to "take control" of input buffers if they have singular refcount - in particular to mutate their raw data if non-readonly via discarding of read bytes, etc.
However there are various places (primarily unit tests) where a wrapped byte-array buffer is passed in and the wrapped array is assumed not to change (used after the wrapped buffer is passed to EmbeddedChannel.writeInbound()). This invalid assumption could result in unexpected errors, such as those exposed by #8931.
Modifications
Anywhere that the data passed to writeInbound() might be used again, ensure that either:
- A copy is used rather than wrapping a shared byte array, or
- The buffer is otherwise protected from modification by making it read-only
For the tests, copying is preferred since it still allows the "mutating" optimizations to be exercised.
Results
Avoid possible errors when pipeline assumes it has full control of input buffer.
