Well, not as much, at least.

Commit 07afdf3c 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt 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: NRichard 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: NRichard 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: NRich 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: NRich 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: NRich 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: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2157)

Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2052)

Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2052)

Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2020)

We remove the separate CertificateStatus message for TLSv1.3, and instead
send back the response in the appropriate Certificate message extension.
Reviewed-by: NRich 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: NRich 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: NRich 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: NRich 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

This builds on the work started in 1ab3836b 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Perl changes reviewed by Richard Levitte. Non-perl changes reviewed by Rich
Salz
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard 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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>

In one case we weren't always sending an unexpected message alert if we
don't get what we expect.
Reviewed-by: NRich Salz <rsalz@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: NRich 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: NRich Salz <rsalz@openssl.org>

We should use the macro for testing if we are using TLSv1.3 rather than
checking s->version directly.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Numerous style issues as well as references to TLS1_3_VERSION instead of
SSL_IS_TLS13(s)
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRich 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: NRich 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: NRich 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: NRich Salz <rsalz@openssl.org>

Added some TODOs, refactored a couple of things and added a SSL_IS_TLS13()
macro.
Reviewed-by: NRich Salz <rsalz@openssl.org>