Now, if the directive is given an empty string, such configuration cancels
loading of certificates, in particular, if they would be otherwise inherited
from the previous level. This restores previous behaviour, before variables
support in certificates was introduced (3ab8e1e2f0f7).
With this change, duplicate Content-Length and Transfer-Encoding headers
are now rejected. Further, responses with invalid Content-Length or
Transfer-Encoding headers are now rejected, as well as responses with both
Content-Length and Transfer-Encoding.
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.
Control characters (0x00-0x1f, 0x7f), space, and colon were never allowed in
header names. The only somewhat valid use is header continuation which nginx
never supported and which is explicitly obsolete by RFC 7230.
Previously, such headers were considered invalid and were ignored by default
(as per ignore_invalid_headers directive). With this change, such headers
are unconditionally rejected.
It is expected to make nginx more resilient to various attacks, in particular,
with ignore_invalid_headers switched off (which is inherently unsecure, though
nevertheless sometimes used in the wild).
After 2096b21fcd10, a single RST_STREAM(NO_ERROR) may not result in an error.
This change removes several unnecessary ctx->type checks for such a case.
With this change, it is now possible to use ngx_conf_merge_ptr_value()
to merge complex values. This change follows much earlier changes in
ngx_conf_merge_ptr_value() and ngx_conf_set_str_array_slot()
in 1452:cd586e963db0 (0.6.10) and 1701:40d004d95d88 (0.6.22), and the
change in ngx_conf_set_keyval_slot() (7728:485dba3e2a01, 1.19.4).
To preserve compatibility with existing 3rd party modules, both NULL
and NGX_CONF_UNSET_PTR are accepted for now.
The response size check introduced in 39501ce97e29 did not take into
account possible padding on DATA frames, resulting in incorrect
"upstream sent response body larger than indicated content length" errors
if upstream server used padding in responses with known length.
Fix is to check the actual size of response buffers produced by the code,
similarly to how it is done in other protocols, instead of checking
the size of DATA frames.
Reported at:
http://mailman.nginx.org/pipermail/nginx-devel/2021-March/013907.html
Similarly to the problem fixed in 2096b21fcd10 (ticket #1792),
when a "trailer only" gRPC response (that is, a response with the
END_STREAM flag in the HEADERS frame) was immediately followed by
RST_STREAM(NO_ERROR) in the data preread along with the response
header, RST_STREAM wasn't properly skipped and caused "upstream
rejected request with error 0" errors.
Observed with "unknown service" gRPC errors returned by grpc-go.
Fix is to set ctx->done if we are going to parse additional data,
so the RST_STREAM(NO_ERROR) is properly skipped. Additionally, now
ngx_http_grpc_filter() will complain about frames sent for closed
stream if there are any.
Now "s", "V", and "v" format specifiers may be prefixed with "x" (lowercase)
or "X" (uppercase) to output corresponding data in hexadecimal format.
In collaboration with Maxim Dounin.
Similarly to ssl_conf_command, proxy_ssl_conf_command (grpc_ssl_conf_command,
uwsgi_ssl_conf_command) can be used to set arbitrary OpenSSL configuration
parameters as long as nginx is compiled with OpenSSL 1.0.2 or later,
when connecting to upstream servers with SSL. Full list of available
configuration commands can be found in the SSL_CONF_cmd manual page
(https://www.openssl.org/docs/man1.1.1/man3/SSL_CONF_cmd.html).
With this change, it is now possible to use ngx_conf_merge_ptr_value()
to merge keyval arrays. This change actually follows much earlier
changes in ngx_conf_merge_ptr_value() and ngx_conf_set_str_array_slot()
in 1452:cd586e963db0 (0.6.10) and 1701:40d004d95d88 (0.6.22).
To preserve compatibility with existing 3rd party modules, both NULL
and NGX_CONF_UNSET_PTR are accepted for now.
As long as the "Content-Length" header is given, we now make sure
it exactly matches the size of the response. If it doesn't,
the response is considered malformed and must not be forwarded
(https://tools.ietf.org/html/rfc7540#section-8.1.2.6). While it
is not really possible to "not forward" the response which is already
being forwarded, we generate an error instead, which is the closest
equivalent.
Previous behaviour was to pass everything to the client, but this
seems to be suboptimal and causes issues (ticket #1695). Also this
directly contradicts HTTP/2 specification requirements.
Note that the new behaviour for the gRPC proxy is more strict than that
applied in other variants of proxying. This is intentional, as HTTP/2
specification requires us to do so, while in other types of proxying
malformed responses from backends are well known and historically
tolerated.
As per https://tools.ietf.org/html/rfc7540#section-8.1,
: A server can send a complete response prior to the client
: sending an entire request if the response does not depend on
: any portion of the request that has not been sent and
: received. When this is true, a server MAY request that the
: client abort transmission of a request without error by
: sending a RST_STREAM with an error code of NO_ERROR after
: sending a complete response (i.e., a frame with the
: END_STREAM flag). Clients MUST NOT discard responses as a
: result of receiving such a RST_STREAM, though clients can
: always discard responses at their discretion for other
: reasons.
Previously, RST_STREAM(NO_ERROR) received from upstream after
a frame with the END_STREAM flag was incorrectly treated as an
error. Now, a single RST_STREAM(NO_ERROR) is properly handled.
This fixes problems observed with modern grpc-c [1], as well
as with the Go gRPC module.
[1] https://github.com/grpc/grpc/pull/1661
If ngx_pool_cleanup_add() fails, we have to clean just created SSL context
manually, thus appropriate call added.
Additionally, ngx_pool_cleanup_add() moved closer to ngx_ssl_create() in
the ngx_http_ssl_module, to make sure there are no leaks due to intermediate
code.
If sending request body was not completed (u->request_body_sent is not set),
the upstream keepalive module won't save such a connection. However, it
is theoretically possible (though highly unlikely) that sending of some
control frames can be blocked after the request body was sent. The
ctx->output_blocked flag introduced to disable keepalive in such cases.
The code is now able to parse additional control frames after
the response is received, and can send control frames as well.
This fixes keepalive problems as observed with grpc-c, which can
send window update and ping frames after the response, see
http://mailman.nginx.org/pipermail/nginx/2018-August/056620.html.
In TLSv1.3, NewSessionTicket messages arrive after the handshake and
can come at any time. Therefore we use a callback to save the session
when we know about it. This approach works for < TLSv1.3 as well.
The callback function is set once per location on merge phase.
Since SSL_get_session() in BoringSSL returns an unresumable session for
TLSv1.3, peer save_session() methods have been updated as well to use a
session supplied within the callback. To preserve API, the session is
cached in c->ssl->session. It is preferably accessed in save_session()
methods by ngx_ssl_get_session() and ngx_ssl_get0_session() wrappers.
We copy input buffers to our buffers, so various flags might be
unexpectedly set in buffers returned by ngx_chain_get_free_buf().
In particular, the b->in_file flag might be set when the body was
written to a file in a different context. With sendfile enabled this
in turn might result in protocol corruption if such a buffer was reused
for a control frame.
Make sure to clear buffers and set only fields we really need to be set.
Cast to intermediate "void *" to lose compiler knowledge about the original
type and pass the warning. This is not a real fix but rather a workaround.
Found by gcc8.
All cases are harmless and should not happen on valid values, though can
result in bad values being shown incorrectly in logs.
Found by Coverity (CID 1430311, 1430312, 1430313).
The gRPC protocol makes a distinction between HEADERS frame with
the END_STREAM flag set, and a HEADERS frame followed by an empty
DATA frame with the END_STREAM flag. The latter is not permitted,
and results in errors not being propagated through nginx. Instead,
gRPC clients complain that "server closed the stream without sending
trailers" (seen in grpc-go) or "13: Received RST_STREAM with error
code 2" (seen in grpc-c).
To fix this, nginx now returns HEADERS with the END_STREAM flag if
the response length is known to be 0, and we are not expecting
any trailer headers to be added. And the response length is
explicitly set to 0 in the gRPC proxy if we see initial HEADERS frame
with the END_STREAM flag set.
According to the gRPC protocol specification, the "TE" header is used
to detect incompatible proxies, and at least grpc-c server rejects
requests without "TE: trailers".
To preserve the logic, we have to pass "TE: trailers" to the backend if
and only if the original request contains "trailers" in the "TE" header.
Note that no other TE values are allowed in HTTP/2, so we have to remove
anything else.
The module allows passing requests to upstream gRPC servers.
The module is built by default as long as HTTP/2 support is compiled in.
Example configuration:
grpc_pass 127.0.0.1:9000;
Alternatively, the "grpc://" scheme can be used:
grpc_pass grpc://127.0.0.1:9000;
Keepalive support is available via the upstream keepalive module. Note
that keepalive connections won't currently work with grpc-go as it fails
to handle SETTINGS_HEADER_TABLE_SIZE.
To use with SSL:
grpc_pass grpcs://127.0.0.1:9000;
SSL connections use ALPN "h2" when available. At least grpc-go works fine
without ALPN, so if ALPN is not available we just establish a connection
without it.
Tested with grpc-c++ and grpc-go.
