Some functions were being called from both code that used WPACKETs and code
that did not. Now that more code has been converted to use WPACKETs some of
that duplication can be removed.
Reviewed-by: Rich Salz <rsalz@openssl.org>
We actually construct a HelloVerifyRequest in two places with common code
pulled into a single function. This one commit handles both places.
Reviewed-by: Rich Salz <rsalz@openssl.org>
DTLS can handle out of order record delivery. Additionally since
handshake messages can be bigger than will fit into a single packet, the
messages can be fragmented across multiple records (as with normal TLS).
That means that the messages can arrive mixed up, and we have to
reassemble them. We keep a queue of buffered messages that are "from the
future", i.e. messages we're not ready to deal with yet but have arrived
early. The messages held there may not be full yet - they could be one
or more fragments that are still in the process of being reassembled.
The code assumes that we will eventually complete the reassembly and
when that occurs the complete message is removed from the queue at the
point that we need to use it.
However, DTLS is also tolerant of packet loss. To get around that DTLS
messages can be retransmitted. If we receive a full (non-fragmented)
message from the peer after previously having received a fragment of
that message, then we ignore the message in the queue and just use the
non-fragmented version. At that point the queued message will never get
removed.
Additionally the peer could send "future" messages that we never get to
in order to complete the handshake. Each message has a sequence number
(starting from 0). We will accept a message fragment for the current
message sequence number, or for any sequence up to 10 into the future.
However if the Finished message has a sequence number of 2, anything
greater than that in the queue is just left there.
So, in those two ways we can end up with "orphaned" data in the queue
that will never get removed - except when the connection is closed. At
that point all the queues are flushed.
An attacker could seek to exploit this by filling up the queues with
lots of large messages that are never going to be used in order to
attempt a DoS by memory exhaustion.
I will assume that we are only concerned with servers here. It does not
seem reasonable to be concerned about a memory exhaustion attack on a
client. They are unlikely to process enough connections for this to be
an issue.
A "long" handshake with many messages might be 5 messages long (in the
incoming direction), e.g. ClientHello, Certificate, ClientKeyExchange,
CertificateVerify, Finished. So this would be message sequence numbers 0
to 4. Additionally we can buffer up to 10 messages in the future.
Therefore the maximum number of messages that an attacker could send
that could get orphaned would typically be 15.
The maximum size that a DTLS message is allowed to be is defined by
max_cert_list, which by default is 100k. Therefore the maximum amount of
"orphaned" memory per connection is 1500k.
Message sequence numbers get reset after the Finished message, so
renegotiation will not extend the maximum number of messages that can be
orphaned per connection.
As noted above, the queues do get cleared when the connection is closed.
Therefore in order to mount an effective attack, an attacker would have
to open many simultaneous connections.
Issue reported by Quan Luo.
CVE-2016-2179
Reviewed-by: Richard Levitte <levitte@openssl.org>
Run util/openssl-format-source on ssl/
Some comments and hand-formatted tables were fixed up
manually by disabling auto-formatting.
Reviewed-by: Rich Salz <rsalz@openssl.org>
When handling ECDH check to see if the curve is "custom" (X25519 is
currently the only curve of this type) and instead of setting a curve
NID just allocate a key of appropriate type.
Reviewed-by: Rich Salz <rsalz@openssl.org>
DTLSv1_client_method() is deprecated, but it was the only way to obtain
DTLS1_BAD_VER support. The SSL_OP_CISCO_ANYCONNECT hack doesn't work with
DTLS_client_method(), and it's relatively non-trivial to make it work without
expanding the hack into lots of places.
So deprecate SSL_OP_CISCO_ANYCONNECT with DTLSv1_client_method(), and make
it work with SSL_CTX_set_{min,max}_proto_version(DTLS1_BAD_VER) instead.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
DTLS version numbers are strange and backwards, except DTLS1_BAD_VER so
we have to make a special case for it.
This does leave us with a set of macros which will evaluate their arguments
more than once, but it's not a public-facing API and it's not like this is
the kind of thing where people will be using DTLS_VERSION_LE(x++, y) anyway.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
- Always process ALPN (previously there was an early return in the
certificate status handling)
- Don't send a duplicate alert. Previously, both
ssl_check_clienthello_tlsext_late and its caller would send an
alert. Consolidate alert sending code in the caller.
Reviewed-by: Rich Salz <rsalz@openssl.org>
The ssl3_init_finished_mac() function can fail, in which case we need to
propagate the error up through the stack.
RT#3198
Reviewed-by: Rich Salz <rsalz@openssl.org>
The write BIO for handshake messages is bufferred so that we only write
out to the network when we have a complete flight. There was some
complexity in the buffering logic so that we switched buffering on and
off at various points through out the handshake. The only real reason to
do this was historically it complicated the state machine when you wanted
to flush because you had to traverse through the "flush" state (in order
to cope with NBIO). Where we knew up front that there was only going to
be one message in the flight we switched off buffering to avoid that.
In the new state machine there is no longer a need for a flush state so
it is simpler just to have buffering on for the whole handshake. This
also gives us the added benefit that we can simply call flush after every
flight even if it only has one message in it. This means that BIO authors
can implement their own buffering strategies and not have to be aware of
the state of the SSL object (previously they would have to switch off
their own buffering during the handshake because they could not rely on
a flush being received when they really needed to write data out). This
last point addresses GitHub Issue #322.
Reviewed-by: Andy Polyakov <appro@openssl.org>
This involves providing more session ticket key data, for both the cipher and
the digest
Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Matt Caswell <matt@openssl.org>
GH: #515, MR: #2153
Per RFC 5246,
Note: this extension is not meaningful for TLS versions prior to 1.2.
Clients MUST NOT offer it if they are offering prior versions.
However, even if clients do offer it, the rules specified in [TLSEXT]
require servers to ignore extensions they do not understand.
Although second sentence would suggest that there would be no interop
problems in always offering the extension, WebRTC has reported issues
with Bouncy Castle on < TLS 1.2 ClientHellos that still include
signature_algorithms. See also
https://bugs.chromium.org/p/webrtc/issues/detail?id=4223
RT#4390
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Stephen Henson <steve@openssl.org>
There is a preference for suffixes to indicate that a function is internal
rather than prefixes. Note: the suffix is only required to disambiguate
internal functions and public symbols with the same name (but different
case)
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
There was a lot of naming inconsistency, so we try and standardise on
one form.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
SSL_COMP_free_compression_methods() should not be called expicitly - we
should leave auto-deinit to clean this up instead.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The function pqueue_print is not exported and is never called. Therefore
we should delete it.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Suppress CT callbacks with aNULL or PSK ciphersuites that involve
no certificates. Ditto when the certificate chain is validated via
DANE-TA(2) or DANE-EE(3) TLSA records. Also skip SCT processing
when the chain is fails verification.
Move and consolidate CT callbacks from libcrypto to libssl. We
also simplify the interface to SSL_{,CTX_}_enable_ct() which can
specify either a permissive mode that just collects information or
a strict mode that requires at least one valid SCT or else asks to
abort the connection.
Simplified SCT processing and options in s_client(1) which now has
just a simple pair of "-noct" vs. "-ct" options, the latter enables
the permissive callback so that we can complete the handshake and
report all relevant information. When printing SCTs, print the
validation status if set and not valid.
Signed-off-by: Rob Percival <robpercival@google.com>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
We now send the highest supported version by the client, even if the session
uses an older version.
This fixes 2 problems:
- When you try to reuse a session but the other side doesn't reuse it and
uses a different protocol version the connection will fail.
- When you're trying to reuse a session with an old version you might be
stuck trying to reuse the old version while both sides support a newer
version
Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
GH: #852, MR: #2452
Don't have #error statements in header files, but instead wrap
the contents of that file in #ifndef OPENSSL_NO_xxx
This means it is now always safe to include the header file.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Adjust ssl_set_client_hello_version to get both the minimum and maximum and then
make ssl_set_client_hello_version use the maximum version.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
MR: #1595
* Perform ALPN after the SNI callback; the SSL_CTX may change due to
that processing
* Add flags to indicate that we actually sent ALPN, to properly error
out if unexpectedly received.
* clean up ssl3_free() no need to explicitly clear when doing memset
* document ALPN functions
Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
This capability is required for read pipelining. We will only read in as
many records as will fit in the read buffer (and the network can provide
in one go). The bigger the buffer the more records we can process in
parallel.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Use the new pipeline cipher capability to encrypt multiple records being
written out all in one go. Two new SSL/SSL_CTX parameters can be used to
control how this works: max_pipelines and split_send_fragment.
max_pipelines defines the maximum number of pipelines that can ever be used
in one go for a single connection. It must always be less than or equal to
SSL_MAX_PIPELINES (currently defined to be 32). By default only one
pipeline will be used (i.e. normal non-parallel operation).
split_send_fragment defines how data is split up into pipelines. The number
of pipelines used will be determined by the amount of data provided to the
SSL_write call divided by split_send_fragment. For example if
split_send_fragment is set to 2000 and max_pipelines is 4 then:
SSL_write called with 0-2000 bytes == 1 pipeline used
SSL_write called with 2001-4000 bytes == 2 pipelines used
SSL_write called with 4001-6000 bytes == 3 pipelines used
SSL_write_called with 6001+ bytes == 4 pipelines used
split_send_fragment must always be less than or equal to max_send_fragment.
By default it is set to be equal to max_send_fragment. This will mean that
the same number of records will always be created as would have been
created in the non-parallel case, although the data will be apportioned
differently. In the parallel case data will be spread equally between the
pipelines.
Reviewed-by: Tim Hudson <tjh@openssl.org>
- Always prefer forward-secure handshakes.
- Consistently order ECDSA above RSA.
- Next, always prefer AEADs to non-AEADs, irrespective of strength.
- Within AEADs, prefer GCM > CHACHA > CCM for a given strength.
- Prefer TLS v1.2 ciphers to legacy ciphers.
- Remove rarely used DSS, IDEA, SEED, CAMELLIA, CCM from the default
list to reduce ClientHello bloat.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Disabled by default, but can be enabled by setting the
ct_validation_callback on a SSL or SSL_CTX.
Reviewed-by: Ben Laurie <ben@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Implementation experience has shown that the original plan for async wait
fds was too simplistic. Originally the async logic created a pipe internally
and user/engine code could then get access to it via API calls. It is more
flexible if the engine is able to create its own fd and provide it to the
async code.
Another issue is that there can be a lot of churn in the fd value within
the context of (say) a single SSL connection leading to continually adding
and removing fds from (say) epoll. It is better if we can provide some
stability of the fd value across a whole SSL connection. This is
problematic because an engine has no concept of an SSL connection.
This commit refactors things to introduce an ASYNC_WAIT_CTX which acts as a
proxy for an SSL connection down at the engine layer.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The ssl_set_masks() function no longer depends on the cipher. This
also means there is no need to set the masks for each cipher in
ssl3_choose_cipher.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Add -DBIO_DEBUG to --strict-warnings.
Remove comments about outdated debugging ifdef guards.
Remove md_rand ifdef guarding an assert; it doesn't seem used.
Remove the conf guards in conf_api since we use OPENSSL_assert, not assert.
For pkcs12 stuff put OPENSSL_ in front of the macro name.
Merge TLS_DEBUG into SSL_DEBUG.
Various things just turned on/off asserts, mainly for checking non-NULL
arguments, which is now removed: camellia, bn_ctx, crypto/modes.
Remove some old debug code, that basically just printed things to stderr:
DEBUG_PRINT_UNKNOWN_CIPHERSUITES, DEBUG_ZLIB, OPENSSL_RI_DEBUG,
RL_DEBUG, RSA_DEBUG, SCRYPT_DEBUG.
Remove OPENSSL_SSL_DEBUG_BROKEN_PROTOCOL.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Remove support for static ECDH ciphersuites. They require ECDH keys
in certificates and don't support forward secrecy.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Commit 7823d792d0 added DEFINE_LHASH_OF
to a C source file. DEFINE_LHASH_OF() and DEFINE_STACK_OF() must
be used only in header files to avoid clang warnings for unused
static-inline functions.
Reviewed-by: Rich Salz <rsalz@openssl.org>
To enable heartbeats for DTLS, configure with enable-heartbeats.
Heartbeats for TLS have been completely removed.
This addresses RT 3647
Reviewed-by: Richard Levitte <levitte@openssl.org>
Update ciphers documentation as well (based on -04 rev of ID).
Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@openssl.org>
RT: #4206, GH: #642
PACKET contents should be read-only. To achieve this, also
- constify two user callbacks
- constify BUF_reverse.
Reviewed-by: Rich Salz <rsalz@openssl.org>
There was an unused macro in ssl_locl.h that used an internal
type, so I removed it.
Move bio_st from bio.h to ossl_type.h
Reviewed-by: Andy Polyakov <appro@openssl.org>
This was done by the following
find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
print unless $. == 1 && m@/\* .*\.[ch] \*/@;
close ARGV if eof; # Close file to reset $.
And then some hand-editing of other files.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
This is an internal facility, never documented, not for
public consumption. Move it into ssl (where it's only used
for DTLS).
I also made the typedef's for pqueue and pitem follow our style: they
name structures, not pointers.
Reviewed-by: Richard Levitte <levitte@openssl.org>
It turns out that -pause calls the undocumented function SSL_set_debug.
That just sets flag inside the SSL structure. That flag, despite
the command is never used. So remove the flag, the field, and the
function.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Applications wishing to include their own stacks now just need to include
DEFINE_STACK_OF(foo)
in a header file.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Also tweak some of the code in demos/bio, to enable interactive
testing of BIO_s_accept's use of SSL_dup. Changed the sconnect
client to authenticate the server, which now exercises the new
SSL_set1_host() function.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The protocol selection code is now consolidated in a few consecutive
short functions in a single file and is table driven. Protocol-specific
constraints that influence negotiation are moved into the flags
field of the method structure. The same protocol version constraints
are now applied in all code paths. It is now much easier to add
new protocol versions without reworking the protocol selection
logic.
In the presence of "holes" in the list of enabled client protocols
we no longer select client protocols below the hole based on a
subset of the constraints and then fail shortly after when it is
found that these don't meet the remaining constraints (suiteb, FIPS,
security level, ...). Ideally, with the new min/max controls users
will be less likely to create "holes" in the first place.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Add new flag TLS1_FLAGS_RECEIVED_EXTMS which is set when the peer sends
the extended master secret extension.
Server now sends extms if and only if the client sent extms.
Check consistency of extms extension when resuming sessions following (where
practical) RFC7627.
Reviewed-by: Matt Caswell <matt@openssl.org>
SSL_{CTX}_set_tmp_ecdh() allows to set 1 EC curve and then tries to use it. On
the other hand SSL_{CTX_}set1_curves() allows you to set a list of curves, but
only when SSL_{CTX_}set_ecdh_auto() was called to turn it on.
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
This only gets used to set a specific curve without actually checking that the
peer supports it or not and can therefor result in handshake failures that can
be avoided by selecting a different cipher.
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
Don't hard code EVP_sha* etc for signature algorithms: use table
indices instead. Add SHA224 and SHA512 to tables.
Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Change handshake hash array into a single digest context simplifying the
handhake hash code. Use EVP_md5_sha1() if needed for handshake hashes in
TLS 1.1 and earlier.
Simplify PRF code to also use a single digest and treat EVP_md5_sha1()
as a special case.
Modify algorithm2 field of ciphers to use a single index value for handshake
hash and PRF instead of a bitmap.
Reviewed-by: Matt Caswell <matt@openssl.org>
This patch contains the necessary changes to provide GOST 2012
ciphersuites in TLS. It requires the use of an external GOST 2012 engine.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
The following entry points have been made async aware:
SSL_accept
SSL_read
SSL_write
Also added is a new mode - SSL_MODE_ASYNC. Calling the above functions with
the async mode enabled will initiate a new async job. If an async pause is
encountered whilst executing the job (such as for example if using SHA1/RSA
with the Dummy Async engine), then the above functions return with
SSL_WANT_ASYNC. Calling the functions again (with exactly the same args
as per non-blocking IO), will resume the job where it left off.
Reviewed-by: Rich Salz <rsalz@openssl.org>
There are lots of calls to EVP functions from within libssl There were
various places where we should probably check the return value but don't.
This adds these checks.
Reviewed-by: Richard Levitte <levitte@openssl.org>
