Add new tunable "tune.ssl.maxrecord".
Over SSL/TLS, the client can decipher the data only once it has received
a full record. With large records, it means that clients might have to
download up to 16kB of data before starting to process them. Limiting the
record size can improve page load times on browsers located over high
latency or low bandwidth networks. It is suggested to find optimal values
which fit into 1 or 2 TCP segments (generally 1448 bytes over Ethernet
with TCP timestamps enabled, or 1460 when timestamps are disabled), keeping
in mind that SSL/TLS add some overhead. Typical values of 1419 and 2859
gave good results during tests. Use "strace -e trace=write" to find the
best value.
This trick was first suggested by Mike Belshe :
http://www.belshe.com/2010/12/17/performance-and-the-tls-record-size/
Then requested again by Ilya Grigorik who provides some hints here :
http://ofps.oreilly.com/titles/9781449344764/_transport_layer_security_tls.html#ch04_00000101
Openssl needs to access /dev/urandom to initialize its internal random
number generator. It does so when it needs a random for the first time,
which fails if it is a handshake performed after the chroot(), causing
all SSL incoming connections to fail.
This fix consists in calling RAND_bytes() to produce a random before
the chroot, which will in turn open /dev/urandom before it's too late,
and avoid the issue.
If the random generator fails to work while processing the config,
haproxy now fails with an error instead of causing SSL connections to
fail at runtime.
This new option ensures that there is no possible fallback to a default
certificate if the client does not provide an SNI which is explicitly
handled by a certificate.
At the moment, we need trash chunks almost everywhere and the only
correctly implemented one is in the sample code. Let's move this to
the chunks so that all other places can use this allocator.
Additionally, the get_trash_chunk() function now really returns two
different chunks. Previously it used to always overwrite the same
chunk and point it to a different buffer, which was a bit tricky
because it's not obvious that two consecutive results do alias each
other.
J. Maurice reported that ssllabs.com test affects unrelated
legitimate traffic and cause SSL errors and broken connections.
Sometimes openssl store read/write/handshake errors in a global stack. This
stack is not specific to the current session. Openssl API does not clean the
stack at the beginning of a new read/write. And the function used to retrieve
error ID after read/write, returns the generic error SSL_ERROR_SSL if the
global stack is not empty.
The fix consists in cleaning the errors stack after read/write/handshake
errors.
When using ca_ignore_err/crt_ignore_err, a connection to an untrusted
server raises an error which is ignored. But the next SSL_read() that
encounters EAGAIN raises the error again, breaking the connection.
Subsequent connections don't have this problem because the session has
been stored and is correctly reused without performing a verify again.
The solution consists in correctly flushing the SSL error stack when
ignoring the crt/ca error.
It's annoying that handshake handlers remove themselves from the
connection flags when they fail because there is no way to tell
which one fails. So now we only remove them when they succeed.
SSL_do_handshake is not appropriate for reneg, it's only appropriate at the
beginning of a connection. OpenSSL correctly handles renegs using the data
functions, so we use SSL_peek() here to make its state machine progress if
SSL_renegotiate_pending() says a reneg is pending.
SSL may decide to switch to a handshake in the middle of a transfer due to
a reneg. In this case we don't want to re-enable polling because data might
have been left pending in the buffer. We just want to switch immediately to
the handshake mode.
Instead of storing a couple of (int, ptr) in the struct connection
and the struct session, we use a different method : we only store a
pointer to an integer which is stored inside the target object and
which contains a unique type identifier. That way, the pointer allows
us to retrieve the object type (by dereferencing it) and the object's
address (by computing the displacement in the target structure). The
NULL pointer always corresponds to OBJ_TYPE_NONE.
This reduces the size of the connection and session structs. It also
simplifies target assignment and compare.
In order to improve the generated code, we try to put the obj_type
element at the beginning of all the structs (listener, server, proxy,
si_applet), so that the original and target pointers are always equal.
A lot of code was touched by massive replaces, but the changes are not
that important.
The trash is used everywhere to store the results of temporary strings
built out of s(n)printf, or as a storage for a chunk when chunks are
needed.
Using global.tune.bufsize is not the most convenient thing either.
So let's replace trash with a chunk and directly use it as such. We can
then use trash.size as the natural way to get its size, and get rid of
many intermediary chunks that were previously used.
The patch is huge because it touches many areas but it makes the code
a lot more clear and even outlines places where trash was used without
being that obvious.
We will need to be able to switch server connections on a session and
to keep idle connections. In order to achieve this, the preliminary
requirement is that the connections can survive the session and be
detached from them.
Right now they're still allocated at exactly the same place, so when
there is a session, there are always 2 connections. We could soon
improve on this by allocating the outgoing connection only during a
connect().
This current patch touches a lot of code and intentionally does not
change any functionnality. Performance tests show no regression (even
a very minor improvement). The doc has not yet been updated.
ssl_c_notbefore: start date of client cert (string, eg: "121022182230Z" for YYMMDDhhmmss[Z])
ssl_c_notafter: end date of client cert (string, eg: "121022182230Z" for YYMMDDhhmmss[Z])
ssl_f_notbefore: start date of frontend cert (string, eg: "121022182230Z" for YYMMDDhhmmss[Z])
ssl_f_notafter: end date of frontend cert (string, eg: "121022182230Z" for YYMMDDhhmmss[Z])
ssl_c_key_alg: algo used to encrypt the client's cert key (ex: rsaEncryption)
ssl_f_key_alg: algo used to encrypt the frontend's cert key (ex: rsaEncryption)
ssl_c_s_dn : client cert subject DN (string)
ssl_c_i_dn : client cert issuer DN (string)
ssl_f_s_dn : frontend cert subject DN (string)
ssl_f_i_dn : frontend cert issuer DN (string)
Return either the full DN without params, or just the DN entry (first param) or
its specific occurrence (second param).
While checking haproxy's SSL stack with www.ssllabs.com, it appeared that
immediately closing upon a failed handshake caused a TCP reset to be emitted.
This is because OpenSSL does not consume pending data in the socket buffers.
One side effect is that if the reset packet is lost, the client might not get
it. So now when a handshake fails, we try to clean the socket buffers before
closing, resulting in a clean FIN instead of an RST.
The ssl_npn match could not work by itself because clients do not use
the NPN extension unless the server advertises the protocols it supports.
Thanks to Simone Bordet for the explanations on how to get it right.
These two new log-format tags report the SSL protocol version (%sslv) and the
SSL ciphers (%sslc) used for the connection with the client. For instance, to
append these information just after the client's IP/port address information
on an HTTP log line, use the following configuration :
log-format %Ci:%Cp\ %sslv:%sslc\ [%t]\ %ft\ %b/%s\ %Tq/%Tw/%Tc/%Tr/%Tt\ %st\ %B\ %cc\ \ %cs\ %tsc\ %ac/%fc/%bc/%sc/%rc\ %sq/%bq\ %hr\ %hs\ %{+Q}r
It will report a line such as the following one :
Oct 12 20:47:30 haproxy[9643]: 127.0.0.1:43602 TLSv1:AES-SHA [12/Oct/2012:20:47:30.303] stick2~ stick2/s1 7/0/12/0/19 200 145 - - ---- 0/0/0/0/0 0/0 "GET /?t=0 HTTP/1.0"
It now becomes possible to verify the server's certificate using the "verify"
directive. This one only supports "none" and "required", as it does not make
much sense to also support "optional" here.
All SSL-specific "server" keywords are now processed in ssl_sock.c. At
the moment, there is no more "not implemented" hint when SSL is disabled,
but keywords could be added in server.c if needed.
These ones are used to set the default ciphers suite on "bind" lines and
"server" lines respectively, instead of using OpenSSL's defaults. These
are probably mainly useful for distro packagers.
