ssl_set_handshake_header2() was only ever a temporary name while we had
to have ssl_set_handshake_header() for code that hadn't been converted to
WPACKET yet. No code remains that needed that so we can rename it.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Remove the old ssl_set_handshake_header() implementations. Later we will
rename ssl_set_handshake_header2() to ssl_set_handshake_header().
Reviewed-by: Rich Salz <rsalz@openssl.org>
This was a temporary function needed during the conversion to WPACKET. All
callers have now been converted to the new way of doing this so this
function is no longer required.
Reviewed-by: Rich Salz <rsalz@openssl.org>
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>
This disables some ciphersuites which aren't supported in SSL v3:
specifically PSK ciphersuites which use SHA256 or SHA384 for the MAC.
Thanks to the Open Crypto Audit Project for identifying this issue.
Reviewed-by: Matt Caswell <matt@openssl.org>
The new function SSL_use_certificate_chain_file was always crashing in
the internal function use_certificate_chain_file because it would pass a
NULL value for SSL_CTX *, but use_certificate_chain_file would
unconditionally try to dereference it.
Reviewed-by: Stephen Henson <steve@openssl.org>
There were a few remaining references to SSLv2 support which are no longer
relevant now that it has been removed.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The function dtls1_link_min_mtu() was only used within d1_lib.c so make
it static.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The SSL variable |in_handshake| seems misplaced. It would be better to have
it in the STATEM structure.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The |no_cert_verify| should be in the state machine structure not in SSL
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The next_state variable is no longer needed in the new state machine.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Move some function definitions around within the state machine to make sure
they are in the correct files. Also create a statem_locl.h header for stuff
entirely local to the state machine code and move various definitions into
it.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Pull out the state machine into a separate sub directory. Also moved some
functions which were nothing to do with the state machine but were in state
machine files. Pulled all the SSL_METHOD definitions into one place...most
of those files had very little left in them any more.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
ssl_get_message is no longer used so it should be removed from
ssl_method_st
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Previously each message specific process function would create its own
PACKET structure. Rather than duplicate all of this code lots of times we
should create it in the state machine itself.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The SSL structure contained a "state" variable that kept track of the state
machine in the old code. The new state machine does not use this so it can
be removed.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The SSL structure contained a "type" variable that was set to either
SSL_ST_ACCEPT or SSL_ST_CONNECT depending on whether we are the server or
the client. This duplicates the capability of the "server" variable and was
actually rarely used.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Clean up and remove lots of code that is now no longer needed due to the
move to the new state machine.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Implement all of the necessary changes to make DTLS on the server work
with the new state machine code.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Split the TLS server ssl3_get_* and ssl3_send_* functions into two ready
for the migration to the new state machine code.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Remove all the functions and dead code that is now no longer required as
a result of the DTLS client move into the new state machine code.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Move all DTLS client side processing into the new state machine code. A
subsequent commit will clean up the old dead code.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Create a dtls_get_message function similar to the old dtls1_get_message but
in the format required for the new state machine code. The old function will
eventually be deleted in later commits.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This swaps the implementation of the client TLS state machine to use the
new state machine code instead.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The new state machine code will split up the reading and writing of
hanshake messages into discrete phases. In order to facilitate that the
existing "get" type functions will be split into two halves: one to get
the message and one to process it. The "send" type functions will also have
all work relating to constructing the message split out into a separate
function just for that. For some functions there will also be separate
pre and post "work" phases to prepare or update state.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This is the first drop of the new state machine code.
The rewrite has the following objectives:
- Remove duplication of state code between client and server
- Remove duplication of state code between TLS and DTLS
- Simplify transitions and bring the logic together in a single location
so that it is easier to validate
- Remove duplication of code between each of the message handling functions
- Receive a message first and then work out whether that is a valid
transition - not the other way around (the other way causes lots of issues
where we are expecting one type of message next but actually get something
else)
- Separate message flow state from handshake state (in order to better
understand each)
- message flow state = when to flush buffers; handling restarts in the
event of NBIO events; handling the common flow of steps for reading a
message and the common flow of steps for writing a message etc
- handshake state = what handshake message are we working on now
- Control complexity: only the state machine can change state: keep all
the state changes local to a file
This builds on previous state machine related work:
- Surface CCS processing in the state machine
- Version negotiation rewrite
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
The function ssl3_get_message gets a whole message from the underlying bio
and returns it to the state machine code. The new state machine code will
split this into two discrete steps: get the message header and get the
message body. This commit splits the existing function into these two
sub steps to facilitate the state machine implementation.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Note that this commit constifies a user callback parameter and therefore
will break compilation for applications using this callback. But unless
they are abusing write access to the buffer, the fix is trivial.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Move all packet parsing to the beginning of the method. This limits the
SSLv2 compatibility soup to the parsing, and makes the rest of the
processing uniform.
This is also needed for simpler EMS support: EMS servers need to do an
early scan for EMS to make resumption decisions. This'll be easier when
the entire ClientHello is parsed in the beginning.
As a side effect,
1) PACKETize ssl_get_prev_session and tls1_process_ticket; and
2) Delete dead code for SSL_OP_NETSCAPE_REUSE_CIPHER_CHANGE_BUG.
Reviewed-by: Matt Caswell <matt@openssl.org>
This patch updates the "DEFAULT" cipherstring to be
"ALL:!COMPLEMENTOFDEFAULT:!eNULL". COMPLEMENTOFDEFAULT is now defined
internally by a flag on each ciphersuite indicating whether it should be
excluded from DEFAULT or not. This gives us control at an individual
ciphersuite level as to exactly what is in DEFAULT and what is not.
Finally all DES, RC4 and RC2 ciphersuites are added to COMPLEMENTOFDEFAULT
and hence removed from DEFAULT.
Reviewed-by: Tim Hudson <tjh@openssl.org>
The old implementation of DTLSv1_listen which has now been replaced still
had a few vestiges scattered throughout the code. This commit removes them.
Reviewed-by: Andy Polyakov <appro@openssl.org>
The existing implementation of DTLSv1_listen() is fundamentally flawed. This
function is used in DTLS solutions to listen for new incoming connections
from DTLS clients. A client will send an initial ClientHello. The server
will respond with a HelloVerifyRequest containing a unique cookie. The
client the responds with a second ClientHello - which this time contains the
cookie.
Once the cookie has been verified then DTLSv1_listen() returns to user code,
which is typically expected to continue the handshake with a call to (for
example) SSL_accept().
Whilst listening for incoming ClientHellos, the underlying BIO is usually in
an unconnected state. Therefore ClientHellos can come in from *any* peer.
The arrival of the first ClientHello without the cookie, and the second one
with it, could be interspersed with other intervening messages from
different clients.
The whole purpose of this mechanism is as a defence against DoS attacks. The
idea is to avoid allocating state on the server until the client has
verified that it is capable of receiving messages at the address it claims
to come from. However the existing DTLSv1_listen() implementation completely
fails to do this. It attempts to super-impose itself on the standard state
machine and reuses all of this code. However the standard state machine
expects to operate in a stateful manner with a single client, and this can
cause various problems.
A second more minor issue is that the return codes from this function are
quite confused, with no distinction made between fatal and non-fatal errors.
Most user code treats all errors as non-fatal, and simply retries the call
to DTLSv1_listen().
This commit completely rewrites the implementation of DTLSv1_listen() and
provides a stand alone implementation that does not rely on the existing
state machine. It also provides more consistent return codes.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Since SSLv3, a CipherSuite is always 2 bytes. The only place where we
need 3-byte ciphers is SSLv2-compatible ClientHello processing.
So, remove the ssl_put_cipher_by_char indirection.
Reviewed-by: Rich Salz <rsalz@openssl.org>
For server use a PSK identity hint value in the CERT structure which
is inherited when SSL_new is called and which allows applications to
set hints on a per-SSL basis. The previous version of
SSL_use_psk_identity_hint tried (wrongly) to use the SSL_SESSION structure.
PR#4039
Reviewed-by: Matt Caswell <matt@openssl.org>
This was obsolete in 2001. This is not the same as Gost94 digest.
Thanks to Dmitry Belyavsky <beldmit@gmail.com> for review and advice.
Reviewed-by: Matt Caswell <matt@openssl.org>
Continuing on from the previous commit this moves the processing of DTLS
CCS messages out of the record layer and into the state machine.
Reviewed-by: Tim Hudson <tjh@openssl.org>
The handling of incoming CCS records is a little strange. Since CCS is not
a handshake message it is handled differently to normal handshake messages.
Unfortunately whilst technically it is not a handhshake message the reality
is that it must be processed in accordance with the state of the handshake.
Currently CCS records are processed entirely within the record layer. In
order to ensure that it is handled in accordance with the handshake state
a flag is used to indicate that it is an acceptable time to receive a CCS.
Previously this flag did not exist (see CVE-2014-0224), but the flag should
only really be considered a workaround for the problem that CCS is not
visible to the state machine.
Outgoing CCS messages are already handled within the state machine.
This patch makes CCS visible to the TLS state machine. A separate commit
will handle DTLS.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Provide more robust (inline) functions to replace n2s, n2l, etc. These
functions do the same thing as the previous macros, but also keep track
of the amount of data remaining and return an error if we try to read more
data than we've got.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Add support for RSAPSK, DHEPSK and ECDHEPSK server side.
Update various checks to ensure certificate and server key exchange messages
are only sent when required.
Update message handling. PSK server key exchange parsing now include an
identity hint prefix for all PSK server key exchange messages. PSK
client key exchange message expects PSK identity and requests key for
all PSK key exchange ciphersuites.
Update flags for RSA, DH and ECDH so they are also used in PSK.
Reviewed-by: Matt Caswell <matt@openssl.org>
This flag was not set anywhere within the codebase (only read). It could
only be set by an app reaching directly into s->s3->flags and setting it
directly. However that method became impossible when libssl was opaquified.
Even in 1.0.2/1.0.1 if an app set the flag directly it is only relevant to
ssl3_connect(), which calls SSL_clear() during initialisation that clears
any flag settings. Therefore it could take effect if the app set the flag
after the handshake has started but before it completed. It seems quite
unlikely that any apps really do this (especially as it is completely
undocumented).
The purpose of the flag is suppress flushing of the write bio on the client
side at the end of the handshake after the client has written the Finished
message whilst resuming a session. This enables the client to send
application data as part of the same flight as the Finished message.
This flag also controls the setting of a second flag SSL3_FLAGS_POP_BUFFER.
There is an interesting comment in the code about this second flag in the
implementation of ssl3_write:
/* This is an experimental flag that sends the
* last handshake message in the same packet as the first
* use data - used to see if it helps the TCP protocol during
* session-id reuse */
It seems the experiment did not work because as far as I can tell nothing
is using this code. The above comment has been in the code since SSLeay.
This commit removes support for SSL3_FLAGS_DELAY_CLIENT_FINISHED, as well
as the associated SSL3_FLAGS_POP_BUFFER.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Rewrite ssl3_digest_cached_records handling. Only digest cached records
if digest array is NULL: this means it is safe to call
ssl3_digest_cached_records multiple times (subsequent calls are no op).
Remove flag TLS1_FLAGS_KEEP_HANDSHAKE instead only update handshake buffer
if digest array is NULL.
Add additional "keep" parameter to ssl3_digest_cached_records to indicate
if the handshake buffer should be retained after digesting cached records
(needed for TLS 1.2 client authentication).
Reviewed-by: Matt Caswell <matt@openssl.org>
As numerous comments indicate the certificate and key array is not an
appopriate structure to store the peers certificate: so remove it and
just the s->session->peer instead.
Reviewed-by: Richard Levitte <levitte@openssl.org>
If a NewSessionTicket is received by a multi-threaded client when
attempting to reuse a previous ticket then a race condition can occur
potentially leading to a double free of the ticket data.
CVE-2015-1791
This also fixes RT#3808 where a session ID is changed for a session already
in the client session cache. Since the session ID is the key to the cache
this breaks the cache access.
Parts of this patch were inspired by this Akamai change:
c0bf69a791
Reviewed-by: Rich Salz <rsalz@openssl.org>
Given the pervasive nature of TLS extensions it is inadvisable to run
OpenSSL without support for them. It also means that maintaining
the OPENSSL_NO_TLSEXT option within the code is very invasive (and probably
not well tested). Therefore it is being removed.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Move per-connection state out of the CERT structure: which should just be
for shared configuration data (e.g. certificates to use).
In particular move temporary premaster secret, raw ciphers, peer signature
algorithms and shared signature algorithms.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Following the version negotiation rewrite all of the previous code that was
dedicated to version negotiation can now be deleted - all six source files
of it!!
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
This commit changes the way that we do server side protocol version
negotiation. Previously we had a whole set of code that had an "up front"
state machine dedicated to the negotiating the protocol version. This adds
significant complexity to the state machine. Historically the justification
for doing this was the support of SSLv2 which works quite differently to
SSLv3+. However, we have now removed support for SSLv2 so there is little
reason to maintain this complexity.
The one slight difficulty is that, although we no longer support SSLv2, we
do still support an SSLv3+ ClientHello in an SSLv2 backward compatible
ClientHello format. This is generally only used by legacy clients. This
commit adds support within the SSLv3 code for these legacy format
ClientHellos.
Server side version negotiation now works in much the same was as DTLS,
i.e. we introduce the concept of TLS_ANY_VERSION. If s->version is set to
that then when a ClientHello is received it will work out the most
appropriate version to respond with. Also, SSLv23_method and
SSLv23_server_method have been replaced with TLS_method and
TLS_server_method respectively. The old SSLv23* names still exist as
macros pointing at the new name, although they are deprecated.
Subsequent commits will look at client side version negotiation, as well of
removal of the old s23* code.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Remove RFC2712 Kerberos support from libssl. This code and the associated
standard is no longer considered fit-for-purpose.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Since COMP_METHOD is now defined in comp_lcl.h, it is no
longer possible to create new TLS compression methods without
using the OpenSSL source. Only ZLIB is supported by default.
Also, since the types are opaque, #ifdef guards to use "char *"
instead of the real type aren't necessary.
The changes are actually minor. Adding missing copyright to some
files makes the diff misleadingly big.
Reviewed-by: Matt Caswell <matt@openssl.org>
The return value is checked for 0. This is currently safe but we should
really check for <= 0 since -1 is frequently used for error conditions.
Thanks to Kevin Wojtysiak (Int3 Solutions) and Paramjot Oberoi (Int3
Solutions) for reporting this issue.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Also push some usage of last_write_sequence out of dtls1_retransmit_message
and into the record layer.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The recent updates to libssl to enforce stricter return code checking, left
a small number of instances behind where return codes were being swallowed
(typically because the function they were being called from was declared as
void). This commit fixes those instances to handle the return codes more
appropriately.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Change ssl_set_handshake_header from return void to returning int, and
handle error return code appropriately.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Mark most functions returning a result defined in any libssl header file
with __owur to warn if they are used without checking the return value.
Use -DUNUSED_RETURN compiler flag with gcc to activate these warnings.
Some functions returning a result are skipped if it is common and valid to
use these functions without checking the return value.
Reviewed-by: Richard Levitte <levitte@openssl.org>
It created the cert structure in SSL_CTX or SSL if it was NULL, but they can
never be NULL as the comments already said.
Reviewed-by: Dr. Stephen Henson <steve@openssl.org>
From RFC4507:
"The ticket_lifetime_hint field contains a hint from the server about how
long the ticket should be stored. The value indicates the lifetime in
seconds as a 32-bit unsigned integer in network byte order."
Reviewed-by: Tim Hudson <tjh@openssl.org>
Rewrite ssl3_send_client_key_exchange to retain the premaster secret
instead of using it immediately.
This is needed because the premaster secret is used after the client key
exchange message has been sent to compute the extended master secret.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Retrieve handshake hashes in a separate function. This tidies the existing
code and will be used for extended master secret generation.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Add a "flags" field to SSL_SESSION. This will contain various flags
such as encrypt-then-mac and extended master secret support.
Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
Remove OPENSSL_NO_BUF_FREELISTS. This was turned on by default,
so the work here is removing the 'maintain our own freelist' code.
Also removed a minor old Windows-multibyte/widechar conversion flag.
Reviewed-by: Andy Polyakov <appro@openssl.org>
Remove support for SHA0 and DSS0 (they were broken), and remove
the ability to attempt to build without SHA (it didn't work).
For simplicity, remove the option of not building various SHA algorithms;
you could argue that SHA_224/256/384/512 should be kept, since they're
like crypto algorithms, but I decided to go the other way.
So these options are gone:
GENUINE_DSA OPENSSL_NO_SHA0
OPENSSL_NO_SHA OPENSSL_NO_SHA1
OPENSSL_NO_SHA224 OPENSSL_NO_SHA256
OPENSSL_NO_SHA384 OPENSSL_NO_SHA512
Reviewed-by: Richard Levitte <levitte@openssl.org>
Sometimes it fails to format them very well, and sometimes it corrupts them!
This commit moves some particularly problematic ones.
Reviewed-by: Tim Hudson <tjh@openssl.org>
MS Server gated cryptography is obsolete and dates from the time of export
restrictions on strong encryption and is only used by ancient versions of
MSIE.
Reviewed-by: Matt Caswell <matt@openssl.org>
and instead use the value provided by the underlying BIO. Also provide some
new DTLS_CTRLs so that the library user can set the mtu without needing to
know this constant. These new DTLS_CTRLs provide the capability to set the
link level mtu to be used (i.e. including this IP/UDP overhead). The previous
DTLS_CTRLs required the library user to subtract this overhead first.
Reviewed-by: Tim Hudson <tjh@openssl.org>
The client sends a session ID with the session ticket, and uses
the returned ID to detect resumption, so we do not need to peek
at handshake messages: s->hit tells us explicitly if we're resuming.
An equivalent change was independently made in BoringSSL, see commit
407886f589cf2dbaed82db0a44173036c3bc3317.
Reviewed-by: Matt Caswell <matt@openssl.org>
The supported signature algorithms extension needs to be processed before
the certificate to use is decided and before a cipher is selected (as the
set of shared signature algorithms supported may impact the choice).
Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 56e8dc542b)
Conflicts:
ssl/ssl.h
ssl/ssl_err.c
Support separate parse and add callback arguments.
Add new callback so an application can free extension data.
Change return value for send functions so < 0 is an error 0
omits extension and > 0 includes it. This is more consistent
with the behaviour of other functions in OpenSSL.
Modify parse_cb handling so <= 0 is an error.
Make SSL_CTX_set_custom_cli_ext and SSL_CTX_set_custom_cli_ext argument
order consistent.
NOTE: these changes WILL break existing code.
Remove (now inaccurate) in line documentation.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Use "parse" and "add" for function and callback names instead of
"first" and "second".
Change arguments to callback so the extension type is unsigned int
and the buffer length is size_t. Note: this *will* break existing code.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Reject attempts to use extensions handled internally.
Add flags to each extension structure to indicate if an extension
has been sent or received. Enforce RFC5246 compliance by rejecting
duplicate extensions and unsolicited extensions and only send a
server extension if we have sent the corresponding client extension.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Use the same structure for client and server custom extensions.
Add utility functions in new file t1_ext.c.
Use new utility functions to handle custom server and client extensions
and remove a lot of code duplication.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Move custom extension structures from SSL_CTX to CERT structure.
This change means the form can be revised in future without binary
compatibility issues. Also since CERT is part of SSL structures
so per-SSL custom extensions could be supported in future as well as
per SSL_CTX.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Don't call internal functions directly call them through
SSL_test_functions(). This also makes unit testing work on
Windows and platforms that don't export internal functions
from shared libraries.
By default unit testing is not enabled: it requires the compile
time option "enable-unit-test".
Reviewed-by: Geoff Thorpe <geoff@openssl.org>
Security callback: selects which parameters are permitted including
sensible defaults based on bits of security.
The "parameters" which can be selected include: ciphersuites,
curves, key sizes, certificate signature algorithms, supported
signature algorithms, DH parameters, SSL/TLS version, session tickets
and compression.
In some cases prohibiting the use of a parameters will mean they are
not advertised to the peer: for example cipher suites and ECC curves.
In other cases it will abort the handshake: e.g DH parameters or the
peer key size.
Documentation to follow...
New function ssl_cipher_disabled.
Check for disabled client ciphers using ssl_cipher_disabled.
New function to return only supported ciphers.
New option to ciphers utility to print only supported ciphers.
Add auto DH parameter support. This is roughly equivalent to the
ECDH auto curve selection but for DH. An application can just call
SSL_CTX_set_auto_dh(ctx, 1);
and appropriate DH parameters will be used based on the size of the
server key.
Unlike ECDH there is no way a peer can indicate the range of DH parameters
it supports. Some peers cannot handle DH keys larger that 1024 bits for
example. In this case if you call:
SSL_CTX_set_auto_dh(ctx, 2);
Only 1024 bit DH parameters will be used.
If the server key is 7680 bits or more in size then 8192 bit DH parameters
will be used: these will be *very* slow.
The old export ciphersuites aren't supported but those are very
insecure anyway.
If multiple TLS extensions are expected but not received, the TLS extension and supplemental data 'generate' callbacks are the only chance for the receive-side to trigger a specific TLS alert during the handshake.
Removed logic which no-op'd TLS extension generate callbacks (as the generate callbacks need to always be called in order to trigger alerts), and updated the serverinfo-specific custom TLS extension callbacks to track which custom TLS extensions were received by the client, where no-ops for 'generate' callbacks are appropriate.
New ctrl sets current certificate based on certain criteria. Currently
two options: set the first valid certificate as current and set the
next valid certificate as current. Using these an application can
iterate over all certificates in an SSL_CTX or SSL structure.
DHE is the standard term used by the RFCs and by other TLS
implementations. It's useful to have the internal variables use the
standard terminology.
This patch leaves a synonym SSL_kEDH in place, though, so that older
code can still be built against it, since that has been the
traditional API. SSL_kEDH should probably be deprecated at some
point, though.
ECDHE is the standard term used by the RFCs and by other TLS
implementations. It's useful to have the internal variables use the
standard terminology.
This patch leaves a synonym SSL_kEECDH in place, though, so that older
code can still be built against it, since that has been the
traditional API. SSL_kEECDH should probably be deprecated at some
point, though.
PR#3169
This patch, which currently applies successfully against master and
1_0_2, adds the following functions:
SSL_[CTX_]select_current_cert() - set the current certificate without
disturbing the existing structure.
SSL_[CTX_]get0_chain_certs() - get the current certificate's chain.
SSL_[CTX_]clear_chain_certs() - clear the current certificate's chain.
The patch also adds these functions to, and fixes some existing errors
in, SSL_CTX_add1_chain_cert.pod.
