Reviewed-by: NMatt Caswell <matt@openssl.org>

if we have a malloc |x = OPENSSL_malloc(...)| sometimes we check |x|
for NULL and sometimes we treat it as a boolean |if(!x) ...|. Standardise
the approach in libssl.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Reviewed-by: NAndy Polyakov <appro@openssl.org>

The SSL variable |in_handshake| seems misplaced. It would be better to have
it in the STATEM structure.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Change various state machine functions to use the prefix ossl_statem
instead.
Reviewed-by: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard 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: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard 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: NTim Hudson <tjh@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

PR#4035
Reviewed-by: NMatt 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: NTim Hudson <tjh@openssl.org>

There are many places (nearly 50) where we malloc and then memset.
Add an OPENSSL_zalloc routine to encapsulate that.
(Missed one conversion; thanks Richard)
Also fixes GH328
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NTim Hudson <tjh@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: NMatt Caswell <matt@openssl.org>

Especially since after the #ifdef cleanups this is not useful.
Reviewed-by: NMatt Caswell <matt@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: NTim Hudson <tjh@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

Note: some of the RFC4279 ciphersuites were originally part of PR#2464.
Reviewed-by: NMatt Caswell <matt@openssl.org>

Move PSK premaster secret algorithm to ssl_generate_master secret so
existing key exchange code can be used and modified slightly to add
the PSK wrapping structure.
Reviewed-by: NMatt Caswell <matt@openssl.org>

For SHA384 PRF PSK ciphersuites we have to switch to default PRF for
TLS < 1.2
Reviewed-by: NMatt Caswell <matt@openssl.org>

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

Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NMatt Caswell <matt@openssl.org>

We always free the handshake buffer when digests are freed so move
it into ssl_free_digest_list()
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

This reverts commit d480e182.

Commit broke TLS handshakes due to fragility of digest caching: that will be
fixed separately.
Reviewed-by: NRich Salz <rsalz@openssl.org>

We always free the handshake buffer when digests are freed so move
it into ssl_free_digest_list()
Reviewed-by: NRich Salz <rsalz@openssl.org>

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

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Remove support for the two export grade static DH ciphersuites. These two
ciphersuites were newly added (along with a number of other static DH
ciphersuites) to 1.0.2. However the two export ones have *never* worked
since they were introduced. It seems strange in any case to be adding new
export ciphersuites, and given "logjam" it also does not seem correct to
fix them.
Reviewed-by: NRichard Levitte <levitte@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: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

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

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