With SSL it is possible that an established connection is ready for
reading after the handshake. Further, events might be already disabled
in case of level-triggered event methods. If this happens and
ngx_http_upstream_send_request() blocks waiting for some data from
the upstream, such as flow control in case of gRPC, the connection
will time out due to no read events on the upstream connection.
Fix is to explicitly check the c->read->ready flag if sending request
blocks and post a read event if it is set.
Note that while it is possible to modify ngx_ssl_handshake() to keep
read events active, this won't completely resolve the issue, since
there can be data already received during the SSL handshake
(see 573bd30e46b4).
Hash initialization ignores elements with key.data set to NULL.
Nevertheless, the initial hash bucket size check didn't skip them,
resulting in unnecessary restrictions on, for example, variables with
long names and with the NGX_HTTP_VARIABLE_NOHASH flag.
Fix is to update the initial hash bucket size check to skip elements
with key.data set to NULL, similarly to how it is done in other parts
of the code.
Requires OpenSSL 3.0 compiled with "enable-ktls" option. Further, KTLS
needs to be enabled in kernel, and in OpenSSL, either via OpenSSL
configuration file or with "ssl_conf_command Options KTLS;" in nginx
configuration.
On FreeBSD, kernel TLS is available starting with FreeBSD 13.0, and
can be enabled with "sysctl kern.ipc.tls.enable=1" and "kldload ktls_ocf"
to load a software backend, see man ktls(4) for details.
On Linux, kernel TLS is available starting with kernel 4.13 (at least 5.2
is recommended), and needs kernel compiled with CONFIG_TLS=y (with
CONFIG_TLS=m, which is used at least on Ubuntu 21.04 by default,
the tls module needs to be loaded with "modprobe tls").
While clock_gettime(CLOCK_MONOTONIC_COARSE) is faster than
clock_gettime(CLOCK_MONOTONIC), the latter is fast enough on Linux for
practical usage, and the difference is negligible compared to other costs
at each event loop iteration. On the other hand, CLOCK_MONOTONIC_COARSE
causes various issues with typical CONFIG_HZ=250, notably very inaccurate
limit_rate handling in some edge cases (ticket #1678) and negative difference
between $request_time and $upstream_response_time (ticket #1965).
This is a recommended behavior by RFC 7301 and is useful
for mitigation of protocol confusion attacks [1].
To avoid possible negative effects, list of supported protocols
was extended to include all possible HTTP protocol ALPN IDs
registered by IANA [2], i.e. "http/1.0" and "http/0.9".
[1] https://alpaca-attack.com/
[2] https://www.iana.org/assignments/tls-extensiontype-values/
In b87b7092cedb (nginx 1.21.1), logging level of "upstream sent invalid
header" errors was accidentally changed to "info". This change restores
the "error" level, which is a proper logging level for upstream-side
errors.
The u->keepalive flag is initialized early if the response has no body
(or an empty body), and needs to be reset if there are any extra data,
similarly to how it is done in ngx_http_proxy_copy_filter(). Missed
in 83c4622053b0.
The "proxy_half_close" directive enables handling of TCP half close. If
enabled, connection to proxied server is kept open until both read ends get
EOF. Write end shutdown is properly transmitted via proxy.
Do this only when the entire request body is empty and
r->request_body_in_file_only is set.
The issue manifested itself with missing warning "a client request body is
buffered to a temporary file" when the entire rb->buf is full and all buffers
are delayed by a filter.
This adds new Auth-SSL-Protocol and Auth-SSL-Cipher headers to
the mail proxy auth protocol when SSL is enabled.
This can be useful for detecting users using older clients that
negotiate old ciphers when you want to upgrade to newer
TLS versions of remove suppport for old and insecure ciphers.
You can use your auth backend to notify these users before the
upgrade that they either need to upgrade their client software
or contact your support team to work out an upgrade path.
To load old/weak server or client certificates it might be needed to adjust
the security level, as introduced in OpenSSL 1.1.0. This change ensures that
ciphers are set before loading the certificates, so security level changes
via the cipher string apply to certificate loading.
Export ciphers are forbidden to negotiate in TLS 1.1 and later protocol modes.
They are disabled since OpenSSL 1.0.2g by default unless explicitly configured
with "enable-weak-ssl-ciphers", and completely removed in OpenSSL 1.1.0.
A new behaviour was introduced in OpenSSL 1.1.1e, when a peer does not send
close_notify before closing the connection. Previously, it was to return
SSL_ERROR_SYSCALL with errno 0, known since at least OpenSSL 0.9.7, and is
handled gracefully in nginx. Now it returns SSL_ERROR_SSL with a distinct
reason SSL_R_UNEXPECTED_EOF_WHILE_READING ("unexpected eof while reading").
This leads to critical errors seen in nginx within various routines such as
SSL_do_handshake(), SSL_read(), SSL_shutdown(). The behaviour was restored
in OpenSSL 1.1.1f, but presents in OpenSSL 3.0 by default.
Use of the SSL_OP_IGNORE_UNEXPECTED_EOF option added in OpenSSL 3.0 allows
to set a compatible behaviour to return SSL_ERROR_ZERO_RETURN:
https://git.openssl.org/?p=openssl.git;a=commitdiff;h=09b90e0
See for additional details: https://github.com/openssl/openssl/issues/11381
The OPENSSL_SUPPRESS_DEPRECATED macro is used to suppress deprecation warnings.
This covers Session Tickets keys, SSL Engine, DH low level API for DHE ciphers.
Unlike OPENSSL_API_COMPAT, it works well with OpenSSL built with no-deprecated.
In particular, it doesn't unhide various macros in OpenSSL includes, which are
meant to be hidden under OPENSSL_NO_DEPRECATED.
The only consumer is a callback function for SSL_CTX_set_tmp_rsa_callback()
deprecated in OpenSSL 1.1.0. Now the function is conditionally compiled too.
The latest HTTP/1.1 draft describes Transfer-Encoding in HTTP/1.0 as having
potentially faulty message framing as that could have been forwarded without
handling of the chunked encoding, and forbids processing subsequest requests
over that connection: https://github.com/httpwg/http-core/issues/879.
While handling of such requests is permitted, the most secure approach seems
to reject them.
The c->read->ready and c->write->ready flags might be reset during
the handshake, and not set again if the handshake was finished on
the other event. At the same time, some data might be read from
the socket during the handshake, so missing c->read->ready flag might
result in a connection hang, for example, when waiting for an SMTP
greeting (which was already received during the handshake).
Found by Sergey Kandaurov.
Previously, when cleaning up a QUIC stream in shutdown mode,
ngx_quic_shutdown_quic() was called, which could close the QUIC connection
right away. This could be a problem if the connection was referenced up the
stack. For example, this could happen in ngx_quic_init_streams(),
ngx_quic_close_streams(), ngx_quic_create_client_stream() etc.
With a typical HTTP/3 client the issue is unlikely because of HTTP/3 uni
streams which need a posted event to close. In this case QUIC connection
cannot be closed right away.
Now QUIC connection read event is posted and it will shut down the connection
asynchronously.
After receiving GOAWAY, client is not supposed to create new streams. However,
until client reads this frame, we allow it to create new streams, which are
gracefully rejected. To prevent client from abusing this algorithm, a new
limit is introduced. Upon reaching keepalive_requests * 2, server now closes
the entire QUIC connection claiming excessive load.
The "hq" mode is HTTP/0.9-1.1 over QUIC. The following limits are introduced:
- uni streams are not allowed
- keepalive_requests is enforced
- keepalive_time is enforced
In case of error, QUIC connection is finalized with 0x101 code. This code
corresponds to HTTP/3 General Protocol Error.
Previously, in-flight byte counter and congestion window were properly
maintained, but the limit was not properly implemented.
Now a new datagram is sent only if in-flight byte counter is less than window.
The limit is datagram-based, which means that a single datagram may lead to
exceeding the limit, but the next one will not be sent.
