Previously, all upstream DNS entries would be immediately re-resolved
on config reload. With a large number of upstreams, this creates
a spike of DNS resolution requests. These spikes can overwhelm the
DNS server or cause drops on the network.
This patch retains the TTL of previous resolutions across reloads
by copying each upstream's name's expiry time across configuration
cycles. As a result, no additional resolutions are needed.
After configuration is reloaded, it may take some time for the
re-resolvable upstream servers to resolve and become available
as peers. During this time, client requests might get dropped.
Such servers are now pre-resolved using the "cache" of already
resolved peers from the old shared memory zone.
Specifying the upstream server by a hostname together with the
"resolve" parameter will make the hostname to be periodically
resolved, and upstream servers added/removed as necessary.
This requires a "resolver" at the "http" configuration block.
The "resolver_timeout" parameter also affects when the failed
DNS requests will be attempted again. Responses with NXDOMAIN
will be attempted again in 10 seconds.
Upstream has a configuration generation number that is incremented each
time servers are added/removed to the primary/backup list. This number
is remembered by the peer.init method, and if peer.get detects a change
in configuration, it returns NGX_BUSY.
Each server has a reference counter. It is incremented by peer.get and
decremented by peer.free. When a server is removed, it is removed from
the list of servers and is marked as "zombie". The memory allocated by
a zombie peer is freed only when its reference count becomes zero.
Co-authored-by: Roman Arutyunyan <arut@nginx.com>
Co-authored-by: Sergey Kandaurov <pluknet@nginx.com>
Co-authored-by: Vladimir Homutov <vl@nginx.com>
TLSv1 and TLSv1.1 are formally deprecated and forbidden to negotiate due
to insufficient security reasons outlined in RFC 8996.
TLSv1 and TLSv1.1 are disabled in BoringSSL e95b0cad9 and LibreSSL 3.8.1
in the way they cannot be enabled in nginx configuration. In OpenSSL 3.0,
they are only permitted at security level 0 (disabled by default).
The support is dropped in Chrome 84, Firefox 78, and deprecated in Safari.
This change disables TLSv1 and TLSv1.1 by default for OpenSSL 1.0.1 and
newer, where TLSv1.2 support is available. For older library versions,
which do not have alternatives, these protocol versions remain enabled.
Since a2a513b93c, stream frames no longer need to be retransmitted after it
was deleted. The frames which were retransmitted before, could be stream data
frames sent prior to a RESET_STREAM. Such retransmissions are explicitly
prohibited by RFC 9000, Section 19.4.
EVP_KEY objects are a reference-counted container for key material, shallow
copies and OpenSSL stack management aren't needed as with certificates.
Based on previous work by Mini Hawthorne.
Certificate chains are now loaded once.
The certificate cache provides each chain as a unique stack of reference
counted elements. This shallow copy is required because OpenSSL stacks
aren't reference counted.
Based on previous work by Mini Hawthorne.
Added ngx_openssl_cache_module, which indexes a type-aware object cache.
It maps an id to a unique instance, and provides references to it, which
are dropped when the cycle's pool is destroyed.
The cache will be used in subsequent patches.
Based on previous work by Mini Hawthorne.
Instead of cross-linking the objects using exdata, pointers to configured
certificates are now stored in ngx_ssl_t, and OCSP staples are now accessed
with rbtree in it. This allows sharing these objects between SSL contexts.
Based on previous work by Mini Hawthorne.
Starting from TLSv1.1 (as seen since draft-ietf-tls-rfc2246-bis-00),
the "certificate_authorities" field grammar of the CertificateRequest
message was redone to allow no distinguished names. In TLSv1.3, with
the restructured CertificateRequest message, this can be similarly
done by optionally including the "certificate_authorities" extension.
This allows to avoid sending DNs at all.
In practice, aside from published TLS specifications, all supported
SSL/TLS libraries allow to request client certificates with an empty
DN list for any protocol version. For instance, when operating in
TLSv1, this results in sending the "certificate_authorities" list as
a zero-length vector, which corresponds to the TLSv1.1 specification.
Such behaviour goes back to SSLeay.
The change relaxes the requirement to specify at least one trusted CA
certificate in the ssl_client_certificate directive, which resulted in
sending DNs of these certificates (closes#142). Instead, all trusted
CA certificates can be specified now using the ssl_trusted_certificate
directive if needed. A notable difference that certificates specified
in ssl_trusted_certificate are always loaded remains (see 3648ba7db).
Co-authored-by: Praveen Chaudhary <praveenc@nvidia.com>
Pushes to master and stable branches will result in buildbot-like checks
on multiple OSes and architectures.
Pull requests will be checked on a public Ubuntu GitHub runner.
Unordered chunks could result in trak->end_chunk smaller than trak->start_chunk
in ngx_http_mp4_crop_stsc_data(). Later in ngx_http_mp4_update_stco_atom()
this caused buffer overread while trying to calculate trak->end_offset.
While cropping an stsc atom in ngx_http_mp4_crop_stsc_data(), a 32-bit integer
overflow could happen, which could result in incorrect seeking and a very large
value stored in "samples". This resulted in a large invalid value of
trak->end_chunk_samples. This value is further used to calculate the value of
trak->end_chunk_samples_size in ngx_http_mp4_update_stsz_atom(). While doing
this, a large invalid value of trak->end_chunk_samples could result in reading
memory before stsz atom start. This could potentially result in a segfault.
