If the ticket age calcualtions do not check out then we must not accept
early data (it could be a replay).
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2737)
This adds partial support for TLS 1.3 certificate request message.
The request context and extensions are currently ignored on receive
and set to zero length on send.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2728)
Provide a callback interface that gives the application the ability
to adjust the nascent SSL object at the earliest stage of ClientHello
processing, immediately after extensions have been collected but
before they have been processed.
This is akin to BoringSSL's "select_certificate_cb" (though it is not
API compatible), and as the name indicates, one major use is to examine
the supplied server name indication and select what certificate to
present to the client. However, it can also be used to make more
sweeping configuration changes to the SSL object according to the
selected server identity and configuration. That may include adjusting
the permitted TLS versions, swapping out the SSL_CTX object (as is
traditionally done in a tlsext_servername_callback), changing the
server's cipher list, and more.
We also wish to allow an early callback to indicate that it needs to perform
additional work asynchronously and resume processing later. To that effect,
refactor the second half of tls_process_client_hello() into a subroutine to be
called at the post-processing stage (including the early callback itself), to
allow the callback to result in remaining in the same work stage for a later
call to succeed. This requires allocating for and storing the CLIENTHELLO_MSG
in the SSL object to be preserved across such calls, but the storage is
reclaimed after ClientHello processing finishes.
Information about the CliehtHello is available to the callback by means of
accessor functions that can only be used from the early callback. This allows
extensions to make use of the existing internal parsing machinery without
exposing structure internals (e.g., of PACKET), so that applications do not
have to write fragile parsing code.
Applications are encouraged to utilize an early callback and not use
a servername_callback, in order to avoid unexpected behavior that
occurs due to the relative order of processing between things like
session resumption and the historical servername callback.
Also tidy up nearby style by removing unnecessary braces around one-line
conditional bodies.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Split off the portions that mutate the SSL object into a separate
function that the state machine calls, so that the public API can
be a pure function. (It still needs the SSL parameter in order
to determine what SSL_METHOD's get_cipher_by_char() routine to use,
though.)
Instead of returning the stack of ciphers (functionality that was
not used internally), require using the output parameter, and add
a separate output parameter for the SCSVs contained in the supplied
octets, if desired. This lets us move to the standard return value
convention. Also make both output stacks optional parameters.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Move ssl_bytes_to_cipher_list() to ssl_lib.c and create a public
wrapper around it. This lets application early callbacks easily get
SSL_CIPHER objects from the raw ciphers bytes without having to
reimplement the parsing code. In particular, they do not need to
know the details of the sslv2 format ClientHello's ciphersuite
specifications.
Document the new public function, including the arguably buggy behavior
of modifying the supplied SSL object. On the face of it, such a function
should be able to be pure, just a direct translation of wire octets to
internal data structures.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Now that we have made SCSVs into more of a first-class object, provide
a way for the bytes-to-SSL_CIPHER conversion to actually return them.
Add a flag 'all' to ssl_get_cipher_by_char to indicate that we want
all the known ciphers, not just the ones valid for encryption. This will,
in practice, let the caller retrieve the SCSVs.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Keep track of the length of the pre_proc_exts array.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Modify the API of tls_collect_extensions() to be able to output the number of
extensions that are known (i.e., the length of its 'res' output). This number
can never be zero on a successful return due to the builtin extensions list,
but use a separate output variable so as to not overload the return value
semantics.
Having this value easily available will give consumers a way to avoid repeating
the calculation.
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)
Use negotiated signature algorithm and certificate index in
tls_construct_key_exchange instead of recalculating it.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2623)
Now the certificate and signature algorithm is set in one place we
can use it directly insetad of recalculating it. The old functions
ssl_get_server_send_pkey() and ssl_get_server_cert_index() are no
longer required.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2623)
The original intent of SSL_PKEY_RSA_SIGN and SSL_PKEY_RSA_ENC was to
support two different keys for RSA signing and decrypt. However this
was never implemented and we only ever set one key and the other was
always NULL. Replace with single SSL_PKEY_RSA type.
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2587)
session_ctx and initial_ctx are aliases of each other, and with the
opaque data structures, there's no need to keep both around. Since
there were more references of session_ctx, replace all instances of
initial_ctx with session_ctx.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2334)
Make sure the session version consistency check is inside
ssl_get_prev_session(). Also fixes a bug where an inconsistent version can
cause a seg fault in TLSv1.3.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)
This mops up various edge cases with key_shares and makes sure we still
generate the handshake secret if we haven't been provided with one but we
have a PSK.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)
The record layer was making decisions that should really be left to the
state machine around unexpected handshake messages that are received after
the initial handshake (i.e. renegotiation related messages). This commit
removes that code from the record layer and updates the state machine
accordingly. This simplifies the state machine and paves the way for
handling other messages post-handshake such as the NewSessionTicket in
TLSv1.3.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2259)
The pointer that was freed in the SSLv2 section of ssl_bytes_to_cipher_list
may have stepped up from its allocated position. Use a pointer that is
guaranteed to point at the start of the allocated block instead.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2312)
Well, not as much, at least.
Commit 07afdf3c3a changed things so
that for SSLv2 format ClientHellos we store the cipher list in the
TLS format, i.e., with two bytes per cipher, to be consistent with
historical behavior.
However, the space allocated for the array still performed the computation
with three bytes per cipher, a needless over-allocation (though a relatively
small one, all things considered).
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2281)
SSL_get0_raw_cipherlist() was a little too "raw" in the case of an SSLv2
compat ClientHello. In 1.0.2 and below, during version negotiation, if
we received an SSLv2 compat ClientHello but actually wanted to do SSLv3+
then we would construct a "fake" SSLv3+ ClientHello. This "fake" ClientHello
would have its ciphersuite list converted to the SSLv3+ format. It was
this "fake" raw list that got saved away to later be returned by a call to
SSL_get0_raw_cipherlist().
In 1.1.0+ version negotiation works differently and we process an SSLv2
compat ClientHello directly without the need for an intermediary "fake"
ClientHello. This meant that the raw ciphersuite list being saved was in
the SSLv2 format. Any caller of this function would not expect that and
potentially overread the returned buffer by one byte.
Fixes#2189
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2280)
The flag SSL_VERIFY_CLIENT_ONCE is documented as follows:
B<Server mode:> only request a client certificate on the initial TLS/SSL
handshake. Do not ask for a client certificate again in case of a
renegotiation. This flag must be used together with SSL_VERIFY_PEER.
B<Client mode:> ignored
But the implementation actually did nothing. After the server sends its
ServerKeyExchange message, the code was checking s->session->peer to see if
it is NULL. If it was set then it did not ask for another client
certificate. However s->session->peer will only be set in the event of a
resumption, but a ServerKeyExchange message is only sent in the event of a
full handshake (i.e. no resumption).
The documentation suggests that the original intention was for this to
have an effect on renegotiation, and resumption doesn't come into it.
The fix is to properly check for renegotiation, not whether there is already
a client certificate in the session.
As far as I can tell this has been broken for a *long* time.
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1982)
The siglen value needs to be initialised prior to it being read in the
call to EVP_DigestSignFinal later in this function.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
TLSv1.3 introduces PSS based sigalgs. Offering these in a TLSv1.3 client
implies that the client is prepared to accept these sigalgs even in
TLSv1.2.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
We had an extra layer of indirection in looking up hashes and sigs based
on sigalgs which is now no longer necessary. This removes it.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
In TLSv1.2 an individual sig alg is represented by 1 byte for the hash
and 1 byte for the signature. In TLSv1.3 each sig alg is represented by
two bytes, where the two bytes together represent a single hash and
signature combination. This converts the internal representation of sigalgs
to use a single int for the pair, rather than a pair of bytes.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)
We remove the separate CertificateStatus message for TLSv1.3, and instead
send back the response in the appropriate Certificate message extension.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2020)
Also updates TLSProxy to be able to understand the format and parse the
contained extensions.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2020)
Continuing from the previous commit we also need to extend the extensions
framework to supply the Certificate we just read during parsing.
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2020)
The Certificate message in TLS1.3 has an extensions block for each
Certificate. Therefore we need to extend tls_construct_extensions() to pass
in the certificate we are working on. We also pass in the position in the
chain (with 0 being the first certificate).
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2020)
The existing code used the magic number -1 to represent the absence of
a status_type in the extension. This commit replaces it with a macro.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
In TLS1.3 some ServerHello extensions remain in the ServerHello, while
others move to the EncryptedExtensions message. This commit performs that
move.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Because extensions were keyed by type which is sparse, we were continually
scanning the list to find the one we wanted. The way we stored them also
had the side effect that we were running initialisers/finalisers in a
different oder to the parsers. In this commit we change things so that we
instead key on an index value for each extension.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Remove some functions that are no longer needed now that we have the new
extension framework.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This lays the foundation for a later move to have the extensions built and
placed into the correct message for TLSv1.3 (e.g. ServerHello or
EncryptedExtensions).
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This builds on the work started in 1ab3836b3 and extends is so that
each extension has its own identified parsing functions, as well as an
allowed context identifying which messages and protocols it is relevant for.
Subsequent commits will do a similar job for the ServerHello extensions.
This will enable us to have common functions for processing extension blocks
no matter which of the multiple messages they are received from. In TLSv1.3
a number of different messages have extension blocks, and some extensions
have moved from one message to another when compared to TLSv1.2.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
At this stage the message is just empty. We need to fill it in with
extension data.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
There are some minor differences in the format of a ServerHello in TLSv1.3.
Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
This is a major overhaul of the TLSv1.3 state machine. Currently it still
looks like TLSv1.2. This commit changes things around so that it starts
to look a bit less like TLSv1.2 and bit more like TLSv1.3.
After this commit we have:
ClientHello
+ key_share ---->
ServerHello
+key_share
{CertificateRequest*}
{Certificate*}
{CertificateStatus*}
<---- {Finished}
{Certificate*}
{CertificateVerify*}
{Finished} ---->
[ApplicationData] <---> [Application Data]
Key differences between this intermediate position and the final TLSv1.3
position are:
- No EncryptedExtensions message yet
- No server side CertificateVerify message yet
- CertificateStatus still exists as a separate message
- A number of the messages are still in the TLSv1.2 format
- Still running on the TLSv1.2 record layer
Reviewed-by: Rich Salz <rsalz@openssl.org>
TLSv1.3 has a NewSessionTicket message, but it is *completely* different to
the TLSv1.2 one and may as well have been called something else. This commit
removes the old style NewSessionTicket from TLSv1.3. We will have to add the
new style one back in later.
Reviewed-by: Rich Salz <rsalz@openssl.org>
The previous commits put in place the logic to exchange key_share data. We
now need to do something with that information. In <= TLSv1.2 the equivalent
of the key_share extension is the ServerKeyExchange and ClientKeyExchange
messages. With key_share those two messages are no longer necessary.
The commit removes the SKE and CKE messages from the TLSv1.3 state machine.
TLSv1.3 is completely different to TLSv1.2 in the messages that it sends
and the transitions that are allowed. Therefore, rather than extend the
existing <=TLS1.2 state transition functions, we create a whole new set for
TLSv1.3. Intially these are still based on the TLSv1.2 ones, but over time
they will be amended.
The new TLSv1.3 transitions remove SKE and CKE completely. There's also some
cleanup for some stuff which is not relevant to TLSv1.3 and is easy to
remove, e.g. the DTLS support (we're not doing DTLSv1.3 yet) and NPN.
I also disable EXTMS for TLSv1.3. Using it was causing some added
complexity, so rather than fix it I removed it, since eventually it will not
be needed anyway.
Reviewed-by: Rich Salz <rsalz@openssl.org>
At the moment the server doesn't yet do anything with this information.
We still need to send the server's key_share info back to the client. That
will happen in subsequent commits.
Reviewed-by: Rich Salz <rsalz@openssl.org>
This is a skin deep change, which simply renames most places where we talk
about curves in a TLS context to groups. This is because TLS1.3 has renamed
the extension, and it can now include DH groups too. We still only support
curves, but this rename should pave the way for a future extension for DH
groups.
Reviewed-by: Rich Salz <rsalz@openssl.org>
The size if fixed by the protocol and won't change even if
sizeof(clienthello.random) does.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Add a blank line, take one away - due to feedback received during review.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
We should be freeing up the raw extension data after we've finished with it.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
In the case of an SSLv2 compat ClientHello we weren't setting up the
compression methods correctly, which could lead to uninit reads or crashes.
Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
We now set the handshake header, and close the packet directly in the
write_state_machine. This is now possible because it is common for all
messages.
Reviewed-by: Rich Salz <rsalz@openssl.org>
tls_construct_finished() used to have different arguments to all of the
other construction functions. It doesn't anymore, so there is no neeed to
treat it as a special case.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Ensure all message types work the same way including CCS so that the state
machine doesn't need to know about special cases. Put all the special logic
into ssl_set_handshake_header() and ssl_close_construct_packet().
Reviewed-by: Rich Salz <rsalz@openssl.org>
Instead of initialising, finishing and cleaning up the WPACKET in every
message construction function, we should do it once in
write_state_machine().
Reviewed-by: Rich Salz <rsalz@openssl.org>
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>
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>
The function tls_construct_cert_status() is called by both TLS and DTLS
code. However it only ever constructed a TLS message header for the message
which obviously failed in DTLS.
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>
Fix some indentation at the same time
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1292)
- 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>
Don't call strncpy with strlen of the source as the length. Don't call
strlen multiple times. Eventually we will want to replace this with a proper
PACKET style handling (but for construction of PACKETs instead of just
reading them as it is now). For now though this is safe because
PSK_MAX_IDENTITY_LEN will always fit into the destination buffer.
This addresses an OCAP Audit issue.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Continuing from the previous commits, this splits out the GOST code into
a separate function from the process CKE code.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Continuing from the previous commits, this splits out the ECDHE code into
a separate function from the process CKE code.
Reviewed-by: Richard Levitte <levitte@openssl.org>
Continuing from the previous commit, this splits out the DHE code into
a separate function from the process CKE code.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The tls_process_client_key_exchange() function is far too long. This
splits out the PSK preamble processing, and the RSA processing into
separate functions.
Reviewed-by: Richard Levitte <levitte@openssl.org>
In preparation for splitting this function up into smaller functions this
commit reduces the scope of some of the variables to only be in scope for
the algorithm specific parts. In some cases that makes the error handling
more verbose than it needs to be - but we'll clean that up in a later
commit.
Reviewed-by: Richard Levitte <levitte@openssl.org>
The logic testing whether a CKE message is allowed or not was a little
difficult to follow. This tries to clean it up.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
Having received a ClientKeyExchange message instead of a Certificate we
know that we are not going to receive a CertificateVerify message. This
means we can free up the handshake_buffer. However we better call
ssl3_digest_cached_records() instead of just freeing it up, otherwise we
later try and use it anyway and a core dump results. This could happen,
for example, in SSLv3 where we send a CertificateRequest but the client
sends no Certificate message at all. This is valid in SSLv3 (in TLS
clients are required to send an empty Certificate message).
Found using the BoringSSL test suite.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
In TLS if the server sends a CertificateRequest and the client does not
provide one, if the server cannot continue it should send a
HandshakeFailure alert. In SSLv3 the same should happen, but instead we
were sending an UnexpectedMessage alert. This is incorrect - the message
isn't unexpected - it is valid for the client not to send one - its just
that we cannot continue without one.
Reviewed-by: Emilia Käsper <emilia@openssl.org>
We calculate the size required for the ServerKeyExchange message and then
call BUF_MEM_grow_clean() on the buffer. However we fail to take account of
2 bytes required for the signature algorithm and 2 bytes for the signature
length, i.e. we could overflow by 4 bytes. In reality this won't happen
because the buffer is pre-allocated to a large size that means it should be
big enough anyway.
Addresses an OCAP Audit issue.
Reviewed-by: Rich Salz <rsalz@openssl.org>
