If a server presents an unexpected certificate to haproxy, that is, a
certificate that doesn't match the expected name as configured in
verifyhost or as requested using SNI, we want to store that precious
information. Fortunately we have access to the connection in the
verification callback so it's possible to store an error code there.
For this purpose we use CO_ER_SSL_MISMATCH_SNI (for when the cert name
didn't match the one requested using SNI) and CO_ER_SSL_MISMATCH for
when it doesn't match verifyhost.
Commit 2ab8867 ("MINOR: ssl: compare server certificate names to the SNI
on outgoing connections") introduced the ability to check server cert
names against the name provided with in the SNI, but verifyhost was kept
as a way to force the name to check against. This was a mistake, because :
- if an SNI is used, any static hostname in verifyhost will be wrong ;
worse, if it matches and doesn't match the SNI, the server presented
the wrong certificate ;
- there's no way to have a default name to check against for health
checks anymore because the point above mandates the removal of the
verifyhost directive
This patch reverses the ordering of the check : whenever SNI is used, the
name provided always has precedence (ie the server must always present a
certificate that matches the requested name). And if no SNI is provided,
then verifyhost is used, and will be configured to match the server's
default certificate name. This will work both when SNI is not used and
for health checks.
If the commit 2ab8867 is backported in 1.7 and/or 1.6, this one must be
backported too.
This patch fixes the commit 2ab8867 ("MINOR: ssl: compare server certificate
names to the SNI on outgoing connections")
When we check the certificate sent by a server, in the verify callback, we get
the SNI from the session (SSL_SESSION object). In OpenSSL, tlsext_hostname value
for this session is copied from the ssl connection (SSL object). But the copy is
done only if the "server_name" extension is found in the server hello
message. This means the server has found a certificate matching the client's
SNI.
When the server returns a default certificate not matching the client's SNI, it
doesn't set any "server_name" extension in the server hello message. So no SNI
is set on the SSL session and SSL_SESSION_get0_hostname always returns NULL.
To fix the problemn, we get the SNI directly from the SSL connection. It is
always defined with the value set by the client.
If the commit 2ab8867 is backported in 1.7 and/or 1.6, this one must be
backported too.
Note: it's worth mentionning that by making the SNI check work, we
introduce another problem by which failed SNI checks can cause
long connection retries on the server, and in certain cases the
SNI value used comes from the client. So this patch series must
not be backported until this issue is resolved.
The commit 5db33cbd "MEDIUM: ssl: ssl_methods implementation is reworked and
factored for min/max tlsxx" drop the case when ssl lib have removed SSLv3.
The commit 1e59fcc5 "BUG/MINOR: ssl: Be sure that SSLv3 connection methods
exist for openssl < 1.1.0" fix build but it's false because haproxy think
that ssl lib support SSLv3.
SSL_OP_NO_* are flags to set in ssl_options and is the way haproxy do the
link between ssl capabilities and haproxy configuration. (The mapping table
is done via methodVersions). SSL_OP_NO_* is set to 0 when ssl lib doesn't
support a new TLS version. Older version (like SSLv3) can be removed at
build or unsupported (like libressl). In all case OPENSSL_NO_SSL3 is define.
To keep the same logic, this patch alter SSL_OP_NO_SSLv3 to 0 when SSLv3 is
not supported by ssl lib (when OPENSSL_NO_SSL3 is define).
In ssl_sock_to_buf(), when we face a small read, we used to consider it
as an indication for the end of incoming data, as is the case with plain
text. The problem is that here it's quite different, SSL records are
returned at once so doing so make us wake all the upper layers for each
and every record. Given that SSL records are 16kB by default, this is
rarely observed unless the protocol employs small records or the buffers
are increased. But with 64kB buffers while trying to deal with HTTP/2
frames, the exchanges are obviously suboptimal as there are two messages
per frame (one for the frame header and another one for the frame payload),
causing the H2 parser to be woken up half of the times without being able
to proceed :
try=65536 ret=45
try=65536 ret=16384
try=49152 ret=9
try=49143 ret=16384
try=32759 ret=9
try=32750 ret=16384
try=16366 ret=9
try=32795 ret=27
try=49161 ret=9
try=49152 ret=16384
try=49116 ret=9
try=49107 ret=16384
try=32723 ret=9
try=32714 ret=16384
try=16330 ret=9
try=32831 ret=63
try=49161 ret=9
try=49152 ret=16384
try=49080 ret=9
try=49071 ret=2181
With this change, the buffer can safely be filled with all pending frames
at once when they are available.
When support for passing SNI to the server was added in 1.6-dev3, there
was no way to validate that the certificate presented by the server would
really match the name requested in the SNI, which is quite a problem as
it allows other (valid) certificates to be presented instead (when hitting
the wrong server or due to a man in the middle).
This patch adds the missing check against the value passed in the SNI.
The "verifyhost" value keeps precedence if set. If no SNI is used and
no verifyhost directive is specified, then the certificate name is not
checked (this is unchanged).
In order to extract the SNI value, it was necessary to make use of
SSL_SESSION_get0_hostname(), which appeared in openssl 1.1.0. This is
a trivial function which returns the value of s->tlsext_hostname, so
it was provided in the compat layer for older versions. After some
refinements from Emmanuel, it now builds with openssl 1.0.2, openssl
1.1.0 and boringssl. A test file was provided to ease testing all cases.
After some careful observation period it may make sense to backport
this to 1.7 and 1.6 as some users rightfully consider this limitation
as a bug.
Cc: Emmanuel Hocdet <manu@gandi.net>
Signed-off-by: Willy Tarreau <w@1wt.eu>
This is used to retrieve the TLS ALPN information from a connection. We
also support a fallback to NPN if ALPN doesn't find anything or is not
available on the existing implementation. It happens that depending on
the library version, either one or the other is available. NPN was
present in openssl 1.0.1 (very common) while ALPN is in 1.0.2 and onwards
(still uncommon at the time of writing). Clients are used to send either
one or the other to ensure a smooth transition.
For openssl 1.0.2, SSLv3_server_method and SSLv3_client_method are undefined if
OPENSSL_NO_SSL3_METHOD is set. So we must add a check on this macro before using
these functions.
This patch modifies the way to re-enable the connection from the async fd
handler calling conn_update_sock_polling instead of the conn_fd_handler.
It also ensures that the polling is really stopped on the async fd.
The Openssl's ASYNC API does'nt support moving buffers on SSL_read/write
This patch disables the ASYNC mode dynamically when the handshake
is left and re-enables it on reneg.
This patch ensure that the ASYNC fd handlers won't be wake up
too early, disabling the event cache for this fd on connection close
and when a WANT_ASYNC is rised by Openssl.
The calls to SSL_read/SSL_write/SSL_do_handshake before rising a real read
event from the ASYNC fd, generated an EAGAIN followed by a context switch
for some engines, or a blocked read for the others.
On connection close it resulted in a too early call to SSL_free followed
by a segmentation fault.
SSL/TLS version can be changed per certificat if and only if openssl lib support
earlier callback on handshake and, of course, is implemented in haproxy. It's ok
for BoringSSL. For Openssl, version 1.1.1 have such callback and could support it.
This patch cleanup the usage of set_version func with a more suitable name:
ctx_set_version. It introduce ssl_set_version func (unused for the moment).
This patch adds the support of a maximum of 32 engines
in async mode.
Some tests have been done using 2 engines simultaneously.
This patch also removes specific 'async' attribute from the connection
structure. All the code relies only on Openssl functions.
ssl-mode-async is a global configuration parameter which enables
asynchronous processing in OPENSSL for all SSL connections haproxy
handles. With SSL_MODE_ASYNC set, TLS I/O operations may indicate a
retry with SSL_ERROR_WANT_ASYNC with this mode set if an asynchronous
capable engine is used to perform cryptographic operations. Currently
async mode only supports one async-capable engine.
This is the latest version of the patchset which includes Emeric's
updates :
- improved async fd cleaning when openssl reports an fd to delete
- prevent conn_fd_handler from calling SSL_{read,write,handshake} until
the async fd is ready, as these operations are very slow and waste CPU
- postpone of SSL_free to ensure the async operation can complete and
does not cause a dereference a released SSL.
- proper removal of async fd from the fdtab and removal of the unused async
flag.
This patch adds the global 'ssl-engine' keyword. First arg is an engine
identifier followed by a list of default_algorithms the engine will
operate.
If the openssl version is too old, an error is reported when the option
is used.
In haproxy < 1.8, no-sslv3/no-tlsv1x are ignored when force-sslv3/force-tlsv1x
is used (without warning). With this patch, no-sslv3/no-tlsv1x are ignored when
ssl-min-ver or ssl-max-ver is used (with warning).
When all SSL/TLS versions are disable: generate an error, not a warning.
example: ssl-min-ver TLSV1.3 (or force-tlsv13) with a openssl <= 1.1.0.
'ssl-min-ver' and 'ssl-max-ver' with argument SSLv3, TLSv1.0, TLSv1.1, TLSv1.2
or TLSv1.3 limit the SSL negotiation version to a continuous range. ssl-min-ver
and ssl-max-ver should be used in replacement of no-tls* and no-sslv3. Warning
and documentation are set accordingly.
Plan is to add min-tlsxx max-tlsxx configuration, more consistent than no-tlsxx.
Find the real min/max versions (openssl capabilities and haproxy configuration)
and generate warning with bad versions range.
'no-tlsxx' can generate 'holes':
"The list of protocols available can be further limited using the SSL_OP_NO_X
options of the SSL_CTX_set_options or SSL_set_options functions. Clients should
avoid creating 'holes' in the set of protocols they support, when disabling a
protocol, make sure that you also disable either all previous or all subsequent
protocol versions. In clients, when a protocol version is disabled without
disabling all previous protocol versions, the effect is to also disable all
subsequent protocol versions."
To not break compatibility, "holes" is authorized with warning, because openssl
1.1.0 and boringssl deal with it (keep the upper or lower range depending the
case and version).
Plan is to add min-tlsxx max-tlsxx configuration, more consistent than no-tlsxx.
This patch introduce internal min/max and replace force-tlsxx implementation.
SSL method configuration is store in 'struct tls_version_filter'.
SSL method configuration to openssl setting is abstract in 'methodVersions' table.
With openssl < 1.1.0, SSL_CTX_set_ssl_version is used for force (min == max).
With openssl >= 1.1.0, SSL_CTX_set_min/max_proto_version is used.
Plan is to add min-tlsxx max-tlsxx configuration, more consistent than no-tlsxx.
min-tlsxx and max-tlsxx can be overwrite on local definition. This directives
should be the only ones needed in default-server.
To simplify next patches (rework of tls versions settings with min/max) all
ssl/tls version settings relative to default-server are reverted first:
remove: 'sslv3', 'tls*', 'no-force-sslv3', 'no-force-tls*'.
remove from default-server: 'no-sslv3', 'no-tls*'.
Note:
. force-tlsxx == min-tlsxx + max-tlsxx : would be ok in default-server.
. no-tlsxx is keep for compatibility: should not be propagated to default-server.
This patch replaces the calls to TLSvX_X_client/server/_method
by the new TLS_client/server_method and it uses the new functions
SSL_set_min_proto_version and SSL_set_max_proto_version, setting them
at the wanted protocol version using 'force-' statements.
This patch makes 'default-server' directives support 'sni' settings.
A field 'sni_expr' has been added to 'struct server' to temporary
stores SNI expressions as strings during both 'default-server' and 'server'
lines parsing. So, to duplicate SNI expressions from 'default-server' 'sni' setting
for new 'server' instances we only have to "strdup" these strings as this is
often done for most of the 'server' settings.
Then, sample expressions are computed calling sample_parse_expr() (only for 'server'
instances).
A new function has been added to produce the same error output as before in case
of any error during 'sni' settings parsing (display_parser_err()).
Should not break anything.
This patch makes 'default-server' directive support 'verifyhost' setting.
Note: there was a little memory leak when several 'verifyhost' arguments were
supplied on the same 'server' line.
This patch makes 'default-server' directive support 'send-proxy-v2-ssl'
(resp. 'send-proxy-v2-ssl-cn') setting.
A new keyword 'no-send-proxy-v2-ssl' (resp. 'no-send-proxy-v2-ssl-cn') has been
added to disable 'send-proxy-v2-ssl' (resp. 'send-proxy-v2-ssl-cn') setting both
in 'server' and 'default-server' directives.
This patch makes 'default-server' directive support 'ssl' setting.
A new keyword 'no-ssl' has been added to disable this setting both
in 'server' and 'default-server' directives.
This patch makes 'default-server' directive support 'no-sslv3' (resp. 'no-ssl-reuse',
'no-tlsv10', 'no-tlsv11', 'no-tlsv12', and 'no-tls-tickets') setting.
New keywords 'sslv3' (resp. 'ssl-reuse', 'tlsv10', 'tlsv11', 'tlsv12', and
'tls-no-tickets') have been added to disable these settings both in 'server' and
'default-server' directives.
This patch makes 'default-server' directive support 'force-sslv3'
and 'force-tlsv1[0-2]' settings.
New keywords 'no-force-sslv3' (resp. 'no-tlsv1[0-2]') have been added
to disable 'force-sslv3' (resp. 'force-tlsv1[0-2]') setting both in 'server' and
'default-server' directives.
This patch makes 'default-server' directive support 'check-ssl' setting
to enable SSL for health checks.
A new keyword 'no-check-ssl' has been added to disable this setting both in
'server' and 'default-server' directives.
SSL_CTX_set_ecdh_auto is declared (when present) with #define. A simple #ifdef
avoid to list all cases of ssllibs. It's a placebo in new ssllibs. It's ok with
openssl 1.0.1, 1.0.2, 1.1.0, libressl and boringssl.
Thanks to Piotr Kubaj for postponing and testing with libressl.
Invalid OCSP file (for example empty one that can be used to enable
OCSP response to be set dynamically later) causes errors that are
placed on OpenSSL error stack. Those errors are not cleared so
anything that checks this stack later will fail.
Following configuration:
bind :443 ssl crt crt1.pem crt crt2.pem
With following files:
crt1.pem
crt1.pem.ocsp - empty one
crt2.pem.rsa
crt2.pem.ecdsa
Will fail to load.
This patch should be backported to 1.7.
Use SSL_set_ex_data/SSL_get_ex_data standard API call to store capture.
We need to avoid internal structures/undocumented calls usage to try to
control the beast and limit painful compatibilities.
Bug introduced with "removes SSL_CTX_set_ssl_version call and cleanup CTX
creation": ssl_sock_new_ctx is called before all the bind line is parsed.
The fix consists of separating the use of default_ctx as the initialization
context of the SSL connection via bind_conf->initial_ctx. Initial_ctx contains
all the necessary parameters before performing the selection of the CTX:
default_ctx is processed as others ctx without unnecessary parameters.
This new sample-fetches captures the cipher list offer by the client
SSL connection during the client-hello phase. This is useful for
fingerprint the SSL connection.
