The new "ssl-security-level" option allows one to change the OpenSSL
security level without having to change the openssl.cnf global file of
your distribution. This directives applies on every SSL_CTX context.
People sometimes change their security level directly in the ciphers
directive, however there are some cases when the security level change
is not applied in the right order (for example when applying a DH
param).
Before this patch, it was to possible to trick by using a specific
openssl.cnf file and start haproxy this way:
OPENSSL_CONF=./openssl.cnf ./haproxy -f bug-2468.cfg
Values for the security level can be found there:
https://www.openssl.org/docs/man1.1.1/man3/SSL_CTX_set_security_level.html
This was discussed in github issue #2468.
This commit removes qc_treat_rx_crypto_frms(). This function was used in
a single place inside qc_ssl_provide_all_quic_data(). Besides, its
naming was confusing as conceptually it is directly linked to quic_ssl
module instead of quic_rx.
Thus, body of qc_treat_rx_crypto_frms() is inlined directly inside
qc_ssl_provide_all_quic_data(). Also, qc_ssl_provide_quic_data() is now
only used inside quic_ssl to its scope is set to static. Overall, API
for CRYPTO frame handling is now cleaner.
The previous patch fix the handling of in-order CRYPTO frames which
requires the usage of a new buffer for these data as their handling is
delayed to run under TASK_HEAVY.
In fact, as now all CRYPTO frames handling must be delayed, their
handling can be unify. This is the purpose of this commit, which removes
the just introduced new buffer. Now, all CRYPTO frames are buffered
inside the ncbuf. Unused elements such as crypto_frms member for
encryption level are also removed.
This commit is not a bugcfix but is a direct follow-up to the last one.
As such, it can probably be backported with it to 2.9 to reduce code
differences between these versions.
QUIC relies on SSL_do_hanshake() to be able to validate handshake. As
this function is computation heavy, it is since 2.9 called only under
TASK_HEAVY. This has been implemented by the following patch :
94d20be138
MEDIUM: quic: Heavy task mode during handshake
Instead of handling CRYPTO frames immediately during reception, this
patch delays the process to run under TASK_HEAVY tasklet. A frame copy
is stored in qel.rx.crypto_frms list. However, this frame still
reference the receive buffer. If the receive buffer is cleared before
the tasklet is rescheduled, it will point to garbage data, resulting in
haproxy decryption error. This happens if a fair amount of data is
received constantly to preempt the quic_conn tasklet execution.
This bug can be reproduced with a fair amount of clients. It is
exhibited by 'show quic full' which can report connections blocked on
handshake. Using the following commands result in h2load non able to
complete the last connections.
$ h2load --alpn-list h3 -t 8 -c 800 -m 10 -w 10 -n 8000 "https://127.0.0.1:20443/?s=10k"
Also, haproxy QUIC listener socket mode was active to trigger the issue.
This forces several connections to share the same reception buffer,
rendering the bug even more plausible to occur. It should be possible to
reproduce it with connection socket if increasing the clients amount.
To fix this bug, define a new buffer under quic_cstream. It is used
exclusively to copy CRYPTO data for in-order frame if ncbuf is empty.
This ensures data remains accessible even if receive buffer is cleared.
Note that this fix is only a temporary step. Indeed, a ncbuf is also
already used for out-of-order data. It should be possible to unify its
usage for both in and out-of-order data, rendering this new buffer
instance unnecessary. In this case, several unneeded elements will
become obsolete such as qel.rx.crypto_frms list. This will be done in a
future refactoring patch.
This must be backported up to 2.9.
After handshake completion, QUIC server is responsible to emit
HANDSHAKE_DONE frame. Some clients wait for it to begin STREAM
transfers.
Previously, there was no explicit tasklet_wakeup() after handshake
completion, which is necessary to emit post-handshake frames. In most
cases, this was undetected as most client continue emission which will
reschedule the tasklet. However, as there is no tasklet_wakeup(), this
is not a consistent behavior. If this bug occurs, it causes a connection
freeze, preventing the client to emit any request. The connection is
finally closed on idle timeout.
To fix this, add an explicit tasklet_wakeup() after handshake
completion. It sounds simple enough but in fact it's difficult to find
the correct location efor tasklet_wakeup() invocation, as post-handshake
is directly linked to connection accept, with different orderings.
Notably, if 0-RTT is used, connection can be accepted prior handshake
completion. Another major point is that along HANDSHAKE_DONE frame, a
series of NEW_CONNECTION_ID frames are emitted. However, these new CIDs
allocation must occur after connection is migrated to its new thread as
these CIDs are tied to it. A BUG_ON() is present to check this in
qc_set_tid_affinity().
With all this in mind, 2 locations were selected for the necessary
tasklet_wakeup() :
* on qc_xprt_start() : this is useful for standard case without 0-RTT.
This ensures that this is done only after connection thread migration.
* on qc_ssl_provide_all_quic_data() : this is done on handshake
completion with 0-RTT used. In this case only, connection is already
accepted and migrated, so tasklet_wakeup() is safe.
Note that as a side-change, quic_accept_push_qc() API has evolved to
better reflect differences between standard and 0-RTT usages. It is now
forbidden to call it multiple times on a single quic_conn instance. A
BUG_ON() has been added.
This issue is labelled as medium even though it seems pretty rare. It
was only reproducible using QUIC interop runner, with haproxy compiled
with LibreSSL with quic-go as client. However, affected code parts are
pretty sensible, which justify the chosen severity.
This should fix github issue #2418.
It should be backported up to 2.6, after a brief period of observation.
Note that the extra comment added in qc_set_tid_affinity() can be
removed in 2.6 as thread migration is not implemented for this version.
Other parts should apply without conflict.
Always compile the test of the early_data variable in
"ssl_quic_initial_ctx", this way we can emit a warning about its support
or not.
The test was moved in a more simple preprocessor check which only checks
the new HAVE_SSL_0RTT_QUIC constant.
Could be backported to 2.9 with the 2 previous commits.
However AWS-LC must be excluded of HAVE_SSL_0RTT_QUIC in this version.
This previous commit was not sufficient to completely fix the building issue
in relation with the TLS stack 0-RTT support. LibreSSL was the last TLS
stack to refuse to compile because of undefined a QUIC specific function
for 0-RTT: SSL_set_quic_early_data_enabled().
To get rid of such compilation issues, define HA_OPENSSL_HAVE_0RTT_SUPPORT
only when building against TLS stack with 0-RTT support.
No need to backport.
This commit:
"MINOR: quic: Enable early data at SSL session level (aws-lc)
introduced a build error when using wolfssl as TLS stack
because it references unknown function wolfSSL_set_quic_early_data_enabled()
which is not defined in qc_set_quic_early_data_context() that must not be used
in this case. The compilation of this fonction was enabled for wolfssl when
it should not have by the mentionned commit.
No backport is needed.
Commit f783dd959b ("MINOR: quic: Enable early data at SSL session level
(aws-lc)") introduced a build error when using the openssl compat layer
because it references unknown function SSL_set_quic_early_data_context()
in qc_set_quic_early_data_context() that is not used in this case.
No backport is needed.
This patch impacts only the haproxy builds against aws-lc TLS stack (USE_OPENSSL_AWSLC).
As mentionned by the boringssl documentation, SSL_do_handshake() completes as soon
as ClientHello is processed and server flight sent (from the TLS stack to the
server endpoint I guess). Into QUIC, the completion has as side effect to discard
the Handshake packet number space. If this handshake completion is not deffered,
the Handshake level CRYPTO data will not be sent to the peer (because of the
assotiated packet number space discarding). According to the documentation,
SSL_in_early_data() may be used to do that. If it returns 1, this means that
the handshake is still in progress but has enough progressed to send half-RTT
data.
This patch is required to make the haproxy builds against aws-lc TLS stack support 0-RTT.
This patch impacts only the haproxy build against aws-lc TLS stack (USE_OPENSSL_AWSLC).
Implement qc_set_quic_early_data_enabled() new function to enable
early data at session level. To make QUIC O-RTT work, a context string
must be set calling SSL_set_quic_early_data_context(). This is a
subset of the encoded transport parameters which is used for this.
Note that some application level settings should be also added (TODO).
This patch is required to make 0-RTT work for haproxy builds against aws-lc.
This bug arrived with this commit:
BUG/MINOR: quic: Useless use of non-contiguous buffer for in order CRYPTO data
Before this commit qc->cstream was tested before entering qc_treat_rx_crypto_frms().
This patch restablishes this behavior. Furthermore, it simplyfies
qc_ssl_provide_all_quic_data() which is a little bit ugly: the CRYPTO data
frame may be freed asap in the list_for_each_entry_safe() block after
having store its data pointer and length in local variables.
Also interrupt the CRYPTO data process as soon as qc_ssl_provide_quic_data()
or qc_treat_rx_crypto_frms() fail.
No need to be backported.
This issue could be reproduced with a TLS client certificate verificatio to
generate enough CRYPTO data between the client and haproxy and with dev/udp/udp-perturb
as network perturbator. Haproxy could crash thanks to a BUG_ON() call as soon as
in disorder data were bufferized into a non-contiguous buffer.
There is no need to pass a non NULL non-contiguous to qc_ssl_provide_quic_data()
from qc_ssl_provide_all_quic_data() which handles in order CRYPTO data which
have not been bufferized. If not, the first call to qc_ssl_provide_quic_data()
to process the first block of in order data leads the non-contiguous buffer
head to be advanced to a wrong offset, by <len> bytes which is the length of the
in order CRYPTO frame. This is detected by a BUG_ON() as follows:
FATAL: bug condition "ncb_ret != NCB_RET_OK" matched at src/quic_ssl.c:620
call trace(11):
| 0x5631cc41f3cc [0f 0b 8b 05 d4 df 48 00]: qc_ssl_provide_quic_data+0xca7/0xd78
| 0x5631cc41f6b2 [89 45 bc 48 8b 45 b0 48]: qc_ssl_provide_all_quic_data+0x215/0x576
| 0x5631cc3ce862 [48 8b 45 b0 8b 40 04 25]: quic_conn_io_cb+0x19a/0x8c2
| 0x5631cc67f092 [e9 1b 02 00 00 83 45 e4]: run_tasks_from_lists+0x498/0x741
| 0x5631cc67fb51 [89 c2 8b 45 e0 29 d0 89]: process_runnable_tasks+0x816/0x879
| 0x5631cc625305 [8b 05 bd 0c 2d 00 83 f8]: run_poll_loop+0x8b/0x4bc
| 0x5631cc6259c0 [48 8b 05 b9 ac 29 00 48]: main-0x2c6
| 0x7fa6c34a2ea7 [64 48 89 04 25 30 06 00]: libpthread:+0x7ea7
| 0x7fa6c33c2a2f [48 89 c7 b8 3c 00 00 00]: libc:clone+0x3f/0x5a
Thank you to @Tristan971 for having reported this issue in GH #2095.
No need to backport.
Implement a limit per listener for concurrent number of QUIC
connections. When reached, INITIAL packets for new connections are
automatically dropped until the number of handshakes is reduced.
The limit value is automatically based on listener backlog, which itself
defaults to maxconn.
This feature is important to ensure CPU and memory resources are not
consume if too many handshakes attempt are started in parallel.
Special care is taken if a connection is released before handshake
completion. In this case, counter must be decremented. This forces to
ensure that member <qc.state> is set early in qc_new_conn() before any
quic_conn_release() invocation.
Accounting is implemented for half open connections which represent QUIC
connections waiting for handshake completion. When reaching a certain
limit, Retry mechanism is automatically activated prior to instantiate
new connections.
The issue with this behavior is that two notions are mixed : QUIC
connection handshake phase and Retry which is mechanism against
amplification attacks. As such, only peer address validation should be
taken into account to activate Retry protection.
This patch chooses to reduce the scope of half_open_conn. Now only
connection waiting to validate the peer address are now accounted for.
Most notably, connections instantiated with a validated Retry token
check are not accounted.
One impact of this patch is that it should prevent to activate Retry
mechanism too early, in particular in case if multiple handshakes are
too slow. Another limitation should be implemented to protect against
this scenario.
If the Handshake encryption level could not be allocated, this could lead
to Initial packets to be sent because no Handshake CRYPTO frames were generated.
Furthermore in such an allocation failure case, the connection should be closed
as soon as possible. This is done making ha_quic_set_encryption_secrets() return
0 upon an encryption level allocation failure.
Also fix a typo in the trace in relation to this allocation failure.
No need to be backported.
This patch sets the handshake task in heavy task mode when receiving in disorder
CRYPTO data which results in in order bufferized CRYPTO data. This is done
thanks to a non-contiguous buffer and from qc_handle_crypto_frm() after having
potentially bufferized CRYPTO data in this buffer.
qc_treat_rx_crypto_frms() is no more called from qc_treat_rx_pkts() but instead
this is where the task is set in heavy task mode. Consequently,
this is the job of qc_ssl_provide_all_quic_data() to call directly
qc_treat_rx_crypto_frms() to provide the in order bufferized CRYPTO data to the
TLS stack. As this function releases the non-contiguous buffer for the CRYPTO
data, if possible, there is no need to do that from qc_treat_rx_crypto_frms()
anymore.
Add a new pool for the CRYPTO data frames received in order.
Add ->rx.crypto_frms list to each encryption level to store such frames
when they are received in order from qc_handle_crypto_frm().
Also set the handshake task (qc_conn_io_cb()) in heavy task mode from
this function after having received such frames. When this task
detects that it is set in heavy mode, it calls qc_ssl_provide_all_quic_data()
newly implemented function to provide the CRYPTO data to the TLS task.
Modify quic_conn_enc_level_uninit() to release these CRYPTO frames
when releasing the encryption level they are in relation with.
Similar to the previous commit which check for maxconn before allocating
a QUIC connection, this patch checks for maxsslconn at the same step.
This is necessary as a QUIC connection cannot run without a SSL context.
This should be backported up to 2.6. It relies on the following patch :
"BUG/MINOR: ssl: use a thread-safe sslconns increment"
Move all QUIC trace definitions from quic_conn.h to quic_trace-t.h. Also
remove multiple definition trace_quic macro definition into
quic_trace.h. This forces all QUIC source files who relies on trace to
include it while reducing the size of quic_conn.h.
This bug was detected when compiling haproxy against aws-lc TLS stack
during QUIC interop runner tests. Some algorithms could be negotiated by haproxy
through the TLS stack but not fully supported by haproxy QUIC implentation.
This leaded tls_aead() to return NULL (same thing for tls_md(), tls_hp()).
As these functions returned values were never checked, they could triggered
segfaults.
To fix this, one closes the connection as soon as possible with a
handshake_failure(40) TLS alert. Note that as the TLS stack successfully
negotiates an algorithm, it provides haproxy with CRYPTO data before entering
->set_encryption_secrets() callback. This is why this callback
(ha_set_encryption_secrets() on haproxy side) is modified to release all
the CRYPTO frames before triggering a CONNECTION_CLOSE with a TLS alert. This is
done calling qc_release_pktns_frms() for all the packet number spaces.
Modify some quic_tls_keys_hexdump to avoid crashes when the ->aead or ->hp EVP_CIPHER
are NULL.
Modify qc_release_pktns_frms() to do nothing if the packet number space passed
as parameter is not intialized.
This bug does not impact the QUIC TLS compatibily mode (USE_QUIC_OPENSSL_COMPAT).
Thank you to @ilia-shipitsin for having reported this issue in GH #2309.
Must be backported as far as 2.6.
This patch fixes the build with AWSLC and USE_QUIC=1, this is only meant
to be able to build for now and it's not feature complete.
The set_encryption_secrets callback has been split in set_read_secret
and set_write_secret.
Missing features:
- 0RTT was disabled.
- TLS1_3_CK_CHACHA20_POLY1305_SHA256, TLS1_3_CK_AES_128_CCM_SHA256 were disabled
- clienthello callback is missing, certificate selection could be
limited (RSA + ECDSA at the same time)
ssl_quic_initial_ctx() is supposed to use error count and not errror
code.
Bug was introduced by 557706b3 ("MINOR: quic: Initialize TLS contexts
for QUIC openssl wrapper").
No backport needed.
When built with USE_QUIC_OPENSSL_COMPAT, a warning is emitted when using
allow-0rtt. However this warning is emitted for every allow-0rtt
keywords on the bind line which is confusing, it must only be done in
case the bind is a quic one. Also this does not handle the case where
the allow-0rtt keyword is in the crt-list.
This patch moves the warning to ssl_quic_initial_ctx() in order to emit
the warning in every useful cases.
Move the code which directly calls the functions of the OpenSSL QUIC API into
quic_ssl.c new C file.
Some code have been extracted from qc_conn_finalize() to implement only
the QUIC TLS part (see quic_tls_finalize()) into quic_tls.c.
qc_conn_finalize() has also been exported to be used from this new quic_ssl.c
C module.
