This fix addresses a potential denial-of-service (DoS) vector that can cause an integer overflow in the presence of malicious WebSocket frames.
The fix adds additional checks against the remaining bytes on a connection, as well as a test to prevent regression.
Credit to Max Justicz (https://justi.cz/) for discovering and reporting this, as well as providing a robust PoC and review.
* build: go.mod to go1.12
* bugfix: fix DoS vector caused by readLimit bypass
* test: update TestReadLimit sub-test
* bugfix: payload length 127 should read bytes as uint64
* bugfix: defend against readLength overflows
Fixes#441.
Issue #441 specified a message separator. This PR has a message terminator. A message terminator can be read immediately following a message. A message separator cannot be read until the start of the next message. The message terminator is more useful when the reader is scanning to the terminator before performing some action.
Sorry for the dumbest PR ever, but this tiny addition of a period changes the formatting of this sentence from a header to a regular paragraph in godoc.
Because the net/http server removes \r\n from multi-line header values,
there's no need to to check for \r or \n when skipping whitespace in
headers (see https://godoc.org/net/textproto#Reader.ReadMIMEHeader).
Given this fact, the whitespace test can be simplified to b == ' ' || b
== '\t'. There's no need for the isSpaceOctet bit field in octetTypes.
The isTokenOctet bit field is the only bit field remaining after the
removal of isSpaceOctet. Simplify the code by replacing the
isTokenOctet bit test in octetTypes with an array of booleans called
isTokenOctet.
Declare isTokenOctet as a composite literal instead of constructing it
at runtime.
Add documentation to core functions for parsing HTTP headers.
Fix bug where connection did not return the write buffer to the pool
after a write error. Add test for the same.
Rename messsageWriter.fatal method to endMessage and consolidate all
message cleanup code there. This ensures that the buffer is returned to
pool on all code paths.
Rename Conn.prepMessage to beginMessage for symmetry with endMessage.
Move some duplicated code at calls to prepMessage to beginMessage.
Bonus improvement: Adjust message and buffer size in TestWriteBufferPool
to test that pool works with fragmented messages.
Add table driven test for handling of host in request URL, request
header and TLS server name. In addition to testing various uses of host
names, this test also confirms that host names are handled the same as
the net/http client.
The new table driven test replaces TestDialTLS, TestDialTLSNoverify,
TestDialTLSBadCert and TestHostHeader.
Eliminate duplicated code for constructing root CA.
- Add Go 1.11 to Travis config
- Use short variable declarations where possible.
- Remove unnecessary build tags after move to Go 1.7 min version.
- Simplify composite literals.
- Remove unused fields (err in PerparedMessage)
- Fix errors reported by golint and goword.
Add WriteBufferPool to Dialer and Upgrader. This field specifies a pool
to use for write operations on a connection. Use of the pool can reduce
memory use when there is a modest write volume over a large number of
connections.
Use larger of hijacked buffer and buffer allocated for connection (if
any) as buffer for building handshake response. This decreases possible
allocations when building the handshake response.
Modify bufio reuse test to call Upgrade instead of the internal
newConnBRW. Move the test from conn_test.go to server_test.go because
it's a serer test.
Update newConn and newConnBRW:
- Move the bufio "hacks" from newConnBRW to separate functions and call
these functions directly from Upgrade.
- Rename newConn to newTestConn and move to conn_test.go. Shorten
argument list to common use case.
- Rename newConnBRW to newConn.
- Add pool code to newConn.
Change the subprotocol and extension header names to match the case used
in RFC examples. Other headers names already match the case used in the
examples.
Although the headers names in the handshake are case insensitive, some
libraries expect the exact case used in the RFC examples. This change
allows the package to interoperate with those broken libraries.
Remove the example code to disable origin checks from the documentation.
I am concerned that developers are copying the code without
understanding the security implications of the code. Most applications
should not use this code.
Change the bad origin error message to mention Upgrader.CheckOrigin
Mention cross-site request forgery in the Upgrader.CheckOrigin doc.
The documentation sometimes used the term "frame" when referring to
single frame control messages. Use the term "message" for consistency
in the documentation and to hide a detail that most application
programmers do not need to know about.
Return empty message for CloseNoStatusReceived. This status indicates
that the message is empty, so make it so. Because it's illegal to send
CloseNoStatusReceived, this change should not break a correct
application.
- Bundle the golang.org/x/net/proxy package to x_net_proxy.go. The
package contains a SOCKS5 proxy. The package is bundled to avoid adding
a dependency from the weboscket package to golang.org/x/net.
- Restructure the existing HTTP proxy code so the code can be used as a
dialer with the proxy package.
- Modify Dialer.Dial to use proxy.FromURL.
- Improve tests (avoid modifying package-level data, use timeouts in
tests, use correct proxy URLs in tests).
Fixes#297.
Change the error text for bad handshake errors from
websocket: not a websocket handshake:
to:
websocket: the client is not using the websocket protocol:
The new text should be more helpful to developers who do not know or
understand the details of the protocol.
Test for bad handshake before other request errors.
Matt Silverlock