When enabled, certificate status is stored in cache and is used to validate
the certificate in future requests.
New directive ssl_ocsp_cache is added to configure the cache.
OCSP validation for client certificates is enabled by the "ssl_ocsp" directive.
OCSP responder can be optionally specified by "ssl_ocsp_responder".
When session is reused, peer chain is not available for validation.
If the verified chain contains certificates from the peer chain not available
at the server, validation will fail.
Introduced in 9d2ad2fb4423 available bytes handling in SSL relied
on connection read handler being overwritten to set the ready flag
and the amount of available bytes. This approach is, however, does
not work properly when connection read handler is changed, for example,
when switching to a next pipelined request, and can result in unexpected
connection timeouts, see here:
http://mailman.nginx.org/pipermail/nginx-devel/2019-December/012825.html
Fix is to introduce ngx_event_process_posted_next() instead, which
will set ready and available regardless of how event handler is set.
Added code to track number of bytes available in the socket.
This makes it possible to avoid looping for a long time while
working with fast enough peer when data are added to the socket buffer
faster than we are able to read and process data.
When kernel does not provide number of bytes available, it is
retrieved using ioctl(FIONREAD) as long as a buffer is filled by
SSL_read().
It is assumed that number of bytes returned by SSL_read() is close
to the number of bytes read from the socket, as we do not use
SSL compression. But even if it is not true for some reason, this
is not important, as we post an additional reading event anyway.
Note that data can be buffered at SSL layer, and it is not possible
to simply stop reading at some point and wait till the event will
be reported by the kernel again. This can be only done when there
are no data in SSL buffers, and there is no good way to find out if
it's the case.
Instead of trying to figure out if SSL buffers are empty, this patch
introduces events posted for the next event loop iteration - such
events will be processed only on the next event loop iteration,
after going into the kernel and retrieving additional events. This
seems to be simple and reliable approach.
Dynamic certificates re-introduce problem with incorrect session
reuse (AKA "virtual host confusion", CVE-2014-3616), since there are
no server certificates to generate session id context from.
To prevent this, session id context is now generated from ssl_certificate
directives as specified in the configuration. This approach prevents
incorrect session reuse in most cases, while still allowing sharing
sessions across multiple machines with ssl_session_ticket_key set as
long as configurations are identical.
Passwords have to be copied to the configuration pool to be used
at runtime. Also, to prevent blocking on stdin (with "daemon off;")
an empty password list is provided.
To make things simpler, password handling was modified to allow
an empty array (with 0 elements and elts set to NULL) as an equivalent
of an array with 1 empty password.
If SSL_write_early_data() returned SSL_ERROR_WANT_WRITE, stop further reading
using a newly introduced c->ssl->write_blocked flag, as otherwise this would
result in SSL error "ssl3_write_bytes:bad length". Eventually, normal reading
will be restored by read event posted from successful SSL_write_early_data().
While here, place "SSL_write_early_data: want write" debug on the path.
LibreSSL 2.8.0 "added const annotations to many existing APIs from OpenSSL,
making interoperability easier for downstream applications". This includes
the const change in the SSL_CTX_sess_set_get_cb() callback function (see
9dd43f4ef67e), which breaks compilation.
To fix this, added a condition on how we redefine OPENSSL_VERSION_NUMBER
when working with LibreSSL (see 382fc7069e3a). With LibreSSL 2.8.0,
we now set OPENSSL_VERSION_NUMBER to 0x1010000fL (OpenSSL 1.1.0), so the
appropriate conditions in the code will use "const" as it happens with
OpenSSL 1.1.0 and later versions.
Early data AKA 0-RTT mode is enabled as long as "ssl_early_data on" is
specified in the configuration (default is off).
The $ssl_early_data variable evaluates to "1" if the SSL handshake
isn't yet completed, and can be used to set the Early-Data header as
per draft-ietf-httpbis-replay-04.
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.
This header carries the definition of HMAC_Init_ex(). In OpenSSL this
header is included by <openssl/ssl.h>, but it's not so in BoringSSL.
It's probably a good idea to explicitly include this header anyway,
regardless of whether it's included by other headers or not.
This variable contains URL-encoded client SSL certificate. In contrast
to $ssl_client_cert, it doesn't depend on deprecated header continuation.
The NGX_ESCAPE_URI_COMPONENT variant of encoding is used, so the resulting
variable can be safely used not only in headers, but also as a request
argument.
The $ssl_client_cert variable should be considered deprecated now.
The $ssl_client_raw_cert variable will be eventually renambed back
to $ssl_client_cert.
CVE-2009-3555 is no longer relevant and mitigated by the renegotiation
info extension (secure renegotiation). On the other hand, unexpected
renegotiation still introduces potential security risks, and hence we do
not allow renegotiation on the server side, as we never request renegotiation.
On the client side the situation is different though. There are backends
which explicitly request renegotiation, and disabled renegotiation
introduces interoperability problems. This change allows renegotiation
on the client side, and fixes interoperability problems as observed with
such backends (ticket #872).
Additionally, with TLSv1.3 the SSL_CB_HANDSHAKE_START flag is currently set
by OpenSSL when receiving a NewSessionTicket message, and was detected by
nginx as a renegotiation attempt. This looks like a bug in OpenSSL, though
this change also allows better interoperability till the problem is fixed.
This implies ticket key size of 80 bytes instead of previously used 48,
as both HMAC and AES keys are 32 bytes now. When an old 48-byte ticket key
is provided, we fall back to using backward-compatible AES128 encryption.
OpenSSL switched to using AES256 in 1.1.0, and we are providing equivalent
security. While here, order of HMAC and AES keys was reverted to make
the implementation compatible with keys used by OpenSSL with
SSL_CTX_set_tlsext_ticket_keys().
Prodded by Christian Klinger.
The variable contains a list of curves as supported by the client.
Known curves are listed by their names, unknown ones are shown
in hex, e.g., "0x001d:prime256v1:secp521r1:secp384r1".
Note that OpenSSL uses session data for SSL_get1_curves(), and
it doesn't store full list of curves supported by the client when
serializing a session. As a result $ssl_curves is only available
for new sessions (and will be empty for reused ones).
The variable is only meaningful when using OpenSSL 1.0.2 and above.
With older versions the variable is empty.
The variable contains list of ciphers as supported by the client.
Known ciphers are listed by their names, unknown ones are shown
in hex, e.g., ""AES128-SHA:AES256-SHA:0x00ff".
The variable is fully supported only when using OpenSSL 1.0.2 and above.
With older version there is an attempt to provide some information
using SSL_get_shared_ciphers(). It only lists known ciphers though.
Moreover, as OpenSSL uses session data for SSL_get_shared_ciphers(),
and it doesn't store relevant data when serializing a session. As
a result $ssl_ciphers is only available for new sessions (and not
available for reused ones) when using OpenSSL older than 1.0.2.
Originally, the variables kept a result of X509_NAME_oneline(),
which is, according to the official documentation, a legacy
function. It produces a non standard output form and has
various quirks and inconsistencies.
The RFC2253 compliant behavior is introduced for these variables.
The original variables are available through $ssl_client_s_dn_legacy
and $ssl_client_i_dn_legacy.
With this change it is now possible to load modules compiled without
the "--with-http_ssl_module" configure option into nginx binary compiled
with it, and vice versa (if a module doesn't use ssl-specific functions),
assuming both use the "--with-compat" option.
This patch moves various OpenSSL-specific function calls into the
OpenSSL module and introduces ngx_ssl_ciphers() to make nginx more
crypto-library-agnostic.
A pointer to a previously configured certificate now stored in a certificate.
This makes it possible to iterate though all certificates configured in
the SSL context. This is now used to configure OCSP stapling for all
certificates, and in ngx_ssl_session_id_context().
As SSL_CTX_use_certificate() frees previously loaded certificate of the same
type, and we have no way to find out if it's the case, X509_free() calls
are now posponed till ngx_ssl_cleanup_ctx().
Note that in OpenSSL 1.0.2+ this can be done without storing things in exdata
using the SSL_CTX_set_current_cert() and SSL_CTX_get0_certificate() functions.
These are not yet available in all supported versions though, so it's easier
to continue to use exdata for now.
SSLeay_version() and SSLeay() are no longer available if OPENSSL_API_COMPAT
is set to 0x10100000L. Switched to using OpenSSL_version() instead.
Additionally, we now compare version strings instead of version numbers,
and this correctly works for LibreSSL as well.
LibreSSL defines OPENSSL_VERSION_NUMBER to 0x20000000L, but uses an old
API derived from OpenSSL at the time LibreSSL forked. As a result, every
version check we use to test for new API elements in newer OpenSSL versions
requires an explicit check for LibreSSL.
To reduce clutter, redefine OPENSSL_VERSION_NUMBER to 0x1000107fL if
LibreSSL is used. The same is done by FreeBSD port of LibreSSL.
This context is needed for shared sessions cache to work in configurations
with multiple virtual servers sharing the same port. Unfortunately, OpenSSL
does not provide an API to access the session context, thus storing it
separately.
In collaboration with Vladimir Homutov.
This is really just a prerequisite for building against BoringSSL,
which doesn't provide either of those features.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
Previously, <bn.h>, <dh.h>, <rand.h> and <rsa.h> were pulled in
by <engine.h> using OpenSSL's deprecated interface, which meant
that nginx couldn't have been built with -DOPENSSL_NO_DEPRECATED.
Both <x509.h> and <x509v3.h> are pulled in by <ocsp.h>, but we're
calling X509 functions directly, so let's include those as well.
<crypto.h> is pulled in by virtually everything, but we're calling
CRYPTO_add() directly, so let's include it as well.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
In order to support key rollover, ssl_session_ticket_key can be defined
multiple times. The first key will be used to issue and resume Session
Tickets, while the rest will be used only to resume them.
ssl_session_ticket_key session_tickets/current.key;
ssl_session_ticket_key session_tickets/prev-1h.key;
ssl_session_ticket_key session_tickets/prev-2h.key;
Please note that nginx supports Session Tickets even without explicit
configuration of the keys and this feature should be only used in setups
where SSL traffic is distributed across multiple nginx servers.
Signed-off-by: Piotr Sikora <piotr@cloudflare.com>
This parameter allows to don't require certificate to be signed by
a trusted CA, e.g. if CA certificate isn't known in advance, like in
WebID protocol.
Note that it doesn't add any security unless the certificate is actually
checked to be trusted by some external means (e.g. by a backend).
Patch by Mike Kazantsev, Eric O'Connor.
OCSP response verification is now switched off by default to simplify
configuration, and the ssl_stapling_verify allows to switch it on.
Note that for stapling OCSP response verification isn't something required
as it will be done by a client anyway. But doing verification on a server
allows to mitigate some attack vectors, most notably stop an attacker from
presenting some specially crafted data to all site clients.
This includes the ssl_stapling_responder directive (defaults to OCSP
responder set in certificate's AIA extension).
OCSP response for a given certificate is requested once we get at least
one connection with certificate_status extension in ClientHello, and
certificate status won't be sent in the connection in question. This due
to limitations in the OpenSSL API (certificate status callback is blocking).
Note: SSL_CTX_use_certificate_chain_file() was reimplemented as it doesn't
allow to access the certificate loaded via SSL_CTX.
Very basic version without any OCSP responder query code, assuming valid
DER-encoded OCSP response is present in a ssl_stapling_file configured.
Such file might be produced with openssl like this:
openssl ocsp -issuer root.crt -cert domain.crt -respout domain.staple \
-url http://ocsp.example.com
The directive allows to specify additional trusted Certificate Authority
certificates to be used during certificate verification. In contrast to
ssl_client_certificate DNs of these cerificates aren't sent to a client
during handshake.
Trusted certificates are loaded regardless of the fact whether client
certificates verification is enabled as the same certificates will be
used for OCSP stapling, during construction of an OCSP request and for
verification of an OCSP response.
The same applies to a CRL (which is now always loaded).
Support for TLSv1.1 and TLSv1.2 protocols was introduced in OpenSSL 1.0.1
(-beta1 was recently released). This change makes it possible to disable
these protocols and/or enable them without other protocols.
enabled in any server. The previous r1033 does not help when unused zone
becomes used after reconfiguration, so it is backed out.
The initial thought was to make SSL modules independed from SSL implementation
and to keep OpenSSL code dependance as much as in separate files.
and is shared among all hosts instead of pregenerating for every HTTPS host
on configuraiton phase. This decreases start time for configuration with
large number of HTTPS hosts.
*) test ssl_client_certificate for ssl_verify_client
*) $ssl_client_cert adds TAB before each line except first one
*) $ssl_client_raw_cert contains certificate as is
*) Feature: the $ssl_client_serial variable.
*) Bugfix: in the "!-e" operator of the "if" directive.
Thanks to Andrian Budanstov.
*) Bugfix: while a client certificate verification nginx did not send
to a client the required certificates information.
*) Bugfix: the $document_root variable did not support the variables in
the "root" directive.
*) Feature: the "ssl_verify_client", "ssl_verify_depth", and
"ssl_client_certificate" directives.
*) Change: the $request_method variable now returns the main request
method.
*) Change: the ° symbol codes were changed in koi-win conversion
table.
*) Feature: the euro and N symbols were added to koi-win conversion
table.
*) Bugfix: if nginx distributed the requests among several backends and
some backend failed, then requests intended for this backend was
directed to one live backend only instead of being distributed among
the rest.
*) Change: the "variables_hash_max_size" and
"variables_hash_bucket_size" directives.
*) Feature: the $body_bytes_sent variable can be used not only in the
"log_format" directive.
*) Feature: the $ssl_protocol and $ssl_cipher variables.
*) Feature: the cache line size detection for widespread CPUs at start
time.
*) Feature: now the "accept_mutex" directive is supported using
fcntl(2) on platforms different from i386, amd64, sparc64, and ppc.
*) Feature: the "lock_file" directive and the --with-lock-path=PATH
autoconfiguration directive.
*) Bugfix: if the HTTPS protocol was used in the "proxy_pass" directive
then the requests with the body was not transferred.
*) Feature: the IMAP/POP3 proxy supports STARTTLS and STLS.
*) Bugfix: the IMAP/POP3 proxy did not work with the select, poll, and
/dev/poll methods.
*) Bugfix: in SSI handling.
*) Bugfix: now Solaris sendfilev() is not used to transfer the client
request body to FastCGI-server via the unix domain socket.
*) Bugfix: the "auth_basic" directive did not disable the
authorization; the bug had appeared in 0.3.11.
*) Change: the "valid_referers" directive and the "$invalid_referer"
variable were moved to the new ngx_http_referer_module from the
ngx_http_rewrite_module.
*) Change: the "$apache_bytes_sent" variable name was changed to
"$body_bytes_sent".
*) Feature: the "$sent_http_..." variables.
*) Feature: the "if" directive supports the "=" and "!=" operations.
*) Feature: the "proxy_pass" directive supports the HTTPS protocol.
*) Feature: the "proxy_set_body" directive.
*) Feature: the "post_action" directive.
*) Feature: the ngx_http_empty_gif_module.
*) Feature: the "worker_cpu_affinity" directive for Linux.
*) Bugfix: the "rewrite" directive did not unescape URI part in
redirect, now it is unescaped except the %00-%25 and %7F-%FF
characters.
*) Bugfix: nginx could not be built by the icc 9.0 compiler.
*) Bugfix: if the SSI was enabled for zero size static file, then the
chunked response was encoded incorrectly.
*) Change: the "bl" and "af" parameters of the "listen" directive was
renamed to the "backlog" and "accept_filter".
*) Feature: the "rcvbuf" and "sndbuf" parameters of the "listen"
directive.
*) Change: the "$msec" log parameter does not require now the
additional the gettimeofday() system call.
*) Feature: the -t switch now tests the "listen" directives.
*) Bugfix: if the invalid address was specified in the "listen"
directive, then after the -HUP signal nginx left an open socket in
the CLOSED state.
*) Bugfix: the mime type may be incorrectly set to default value for
index file with variable in the name; the bug had appeared in 0.3.0.
*) Feature: the "timer_resolution" directive.
*) Feature: the millisecond "$upstream_response_time" log parameter.
*) Bugfix: a temporary file with client request body now is removed
just after the response header was transferred to a client.
*) Bugfix: OpenSSL 0.9.6 compatibility.
*) Bugfix: the SSL certificate and key file paths could not be relative.
*) Bugfix: the "ssl_prefer_server_ciphers" directive did not work in
the ngx_imap_ssl_module.
*) Bugfix: the "ssl_protocols" directive allowed to specify the single
protocol only.
*) Feature: the "config errmsg" command of the ngx_http_ssi_module.
*) Change: the ngx_http_geo_module variables can be overridden by the
"set" directive.
*) Feature: the "ssl_protocols" and "ssl_prefer_server_ciphers"
directives of the ngx_http_ssl_module and ngx_imap_ssl_module.
*) Bugfix: the ngx_http_autoindex_module did not show correctly the
long file names;
*) Bugfix: the ngx_http_autoindex_module now do not show the files
starting by dot.
*) Bugfix: if the SSL handshake failed then another connection may be
closed too.
Thanks to Rob Mueller.
*) Bugfix: the export versions of MSIE 5.x could not connect via HTTPS.
*) The pid-file names used during online upgrade was changed and now is
not required a manual rename operation. The old master process adds
the ".oldbin" suffix to its pid-file and executes a new binary file.
The new master process creates usual pid-file without the ".newbin"
suffix. If the master process exits, then old master process renames
back its pid-file with the ".oldbin" suffix to the pid-file without
suffix.
*) Change: the "worker_connections" directive, new name of the
"connections" directive; now the directive specifies maximum number
of connections, but not maximum socket descriptor number.
*) Feature: SSL supports the session cache inside one worker process.
*) Feature: the "satisfy_any" directive.
*) Change: the ngx_http_access_module and ngx_http_auth_basic_module do
not run for subrequests.
*) Feature: the "worker_rlimit_nofile" and "worker_rlimit_sigpending"
directives.
*) Bugfix: if all backend using in load-balancing failed after one
error, then nginx did not try do connect to them during 60 seconds.
*) Bugfix: in IMAP/POP3 command argument parsing.
Thanks to Rob Mueller.
*) Bugfix: errors while using SSL in IMAP/POP3 proxy.
*) Bugfix: errors while using SSI and gzipping.
*) Bugfix: the "Expires" and "Cache-Control" header lines were omitted
from the 304 responses.
Thanks to Alexandr Kukushkin.
*) Change: the "ssl_engine" directive was canceled in the
ngx_http_ssl_module and now is introduced at global level.
*) Bugfix: the responses with SSI subrequests did not transferred via
SSL connection.
*) Various bug fixes in the IMAP/POP3 proxy.
*) Feature: the IMAP/POP3 proxy supports SSL.
*) Feature: the "proxy_timeout" directive of the ngx_imap_proxy_module.
*) Feature: the "userid_mark" directive.
*) Feature: the $remote_user variable value is determined independently
of authorization use.
*) Feature: the ngx_http_ssi_module supports "include virtual" command.
*) Feature: the ngx_http_ssi_module supports the condition command like
'if expr="$NAME"' and "else" and "endif" commands. Only one nested
level is supported.
*) Feature: the ngx_http_ssi_module supports the DATE_LOCAL and
DATE_GMT variables and "config timefmt" command.
*) Feature: the "ssi_ignore_recycled_buffers" directive.
*) Bugfix: the "echo" command did not show the default value for the
empty QUERY_STRING variable.
*) Change: the ngx_http_proxy_module was rewritten.
*) Feature: the "proxy_redirect", "proxy_pass_request_headers",
"proxy_pass_request_body", and "proxy_method" directives.
*) Feature: the "proxy_set_header" directive. The "proxy_x_var" was
canceled and must be replaced with the proxy_set_header directive.
*) Change: the "proxy_preserve_host" is canceled and must be replaced
with the "proxy_set_header Host $host" and the "proxy_redirect off"
directives, the "proxy_set_header Host $host:$proxy_port" directive
and the appropriate proxy_redirect directives.
*) Change: the "proxy_set_x_real_ip" is canceled and must be replaced
with the "proxy_set_header X-Real-IP $remote_addr" directive.
*) Change: the "proxy_add_x_forwarded_for" is canceled and must be
replaced with
the "proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for"
directive.
*) Change: the "proxy_set_x_url" is canceled and must be replaced with
the "proxy_set_header X-URL http://$host:$server_port$request_uri"
directive.
*) Feature: the "fastcgi_param" directive.
*) Change: the "fastcgi_root", "fastcgi_set_var" and "fastcgi_params"
directive are canceled and must be replaced with the fastcgi_param
directives.
*) Feature: the "index" directive can use the variables.
*) Feature: the "index" directive can be used at http and server levels.
*) Change: the last index only in the "index" directive can be absolute.
*) Feature: the "rewrite" directive can use the variables.
*) Feature: the "internal" directive.
*) Feature: the CONTENT_LENGTH, CONTENT_TYPE, REMOTE_PORT, SERVER_ADDR,
SERVER_PORT, SERVER_PROTOCOL, DOCUMENT_ROOT, SERVER_NAME,
REQUEST_METHOD, REQUEST_URI, and REMOTE_USER variables.
*) Change: nginx now passes the invalid lines in a client request
headers or a backend response header.
*) Bugfix: if the backend did not transfer response for a long time and
the "send_timeout" was less than "proxy_read_timeout", then nginx
returned the 408 response.
*) Bugfix: the segmentation fault was occurred if the backend sent an
invalid line in response header; the bug had appeared in 0.1.26.
*) Bugfix: the segmentation fault may occurred in FastCGI fault
tolerance configuration.
*) Bugfix: the "expires" directive did not remove the previous
"Expires" and "Cache-Control" headers.
*) Bugfix: nginx did not take into account trailing dot in "Host"
header line.
*) Bugfix: the ngx_http_auth_module did not work under Linux.
*) Bugfix: the rewrite directive worked incorrectly, if the arguments
were in a request.
*) Bugfix: nginx could not be built on MacOS X.
*) Bugfix: now, if request contains the zero, then the 404 error is
returned for the local requests.
*) Bugfix: nginx could not be built on NetBSD 2.0.
*) Bugfix: the timeout may occur while reading of the the client
request body via SSL connections.
*) Feature: the autoconfiguration directives:
--http-client-body-temp-path=PATH, --http-proxy-temp-path=PATH, and
--http-fastcgi-temp-path=PATH
*) Change: the directory name for the temporary files with the client
request body is specified by directive client_body_temp_path, by
default it is <prefix>/client_body_temp.
*) Feature: the ngx_http_fastcgi_module and the directives:
fastcgi_pass, fastcgi_root, fastcgi_index, fastcgi_params,
fastcgi_connect_timeout, fastcgi_send_timeout, fastcgi_read_timeout,
fastcgi_send_lowat, fastcgi_header_buffer_size, fastcgi_buffers,
fastcgi_busy_buffers_size, fastcgi_temp_path,
fastcgi_max_temp_file_size, fastcgi_temp_file_write_size,
fastcgi_next_upstream, and fastcgi_x_powered_by.
*) Bugfix: the "[alert] zero size buf" error; the bug had appeared in
0.1.3.
*) Change: the URI must be specified after the host name in the
proxy_pass directive.
*) Change: the %3F symbol in the URI was considered as the argument
string start.
*) Feature: the unix domain sockets support in the
ngx_http_proxy_module.
*) Feature: the ssl_engine and ssl_ciphers directives.
Thanks to Sergey Skvortsov for SSL-accelerator.
*) Feature: the worker_priority directive.
*) Change: both tcp_nopush and tcp_nodelay directives affect the
transferred response.
*) Bugfix: nginx did not call initgroups().
Thanks to Andrew Sitnikov and Andrei Nigmatulin.
*) Change: now the ngx_http_autoindex_module shows the file size in the
bytes.
*) Bugfix: the ngx_http_autoindex_module returned the 500 error if the
broken symlink was in a directory.
*) Bugfix: the files bigger than 4G could not be transferred using
sendfile.
*) Bugfix: if the backend was resolved to several backends and there
was an error while the response waiting then process may got caught
in an endless loop.
*) Bugfix: the worker process may exit with the "unknown cycle" message
when the /dev/poll method was used.
*) Bugfix: "close() channel failed" errors.
*) Bugfix: the autodetection of the "nobody" and "nogroup" groups.
*) Bugfix: the send_lowat directive did not work on Linux.
*) Bugfix: the segmentation fault occurred if there was no events
section in configuration.
*) Bugfix: nginx could not be built on OpenBSD.
*) Bugfix: the double slashes in "://" in the URI were converted to
":/".
*) Bugfix: the proxied request was sent without arguments if the
request contains "//", "/./", "/../" or "%XX".
*) Bugfix: the large compressed responses may be transferred not
completely.
*) Bugfix: the files bigger than 2G was not transferred on Linux that
does not support sendfile64().
*) Bugfix: while the build configuration on Linux the
--with-poll_module parameter was required; the bug had appeared in
0.1.8.
