Adding the new state machine broke the DTLSv1_listen code because
calling SSL_in_before() was erroneously returning true after DTLSv1_listen
had successfully completed. This change ensures that SSL_in_before returns
false.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Remove repeated blocks of checking SSL and then SSL_CTX for the
info_callback.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Remove all the defines for the old state machines states. Mapping old to new
is probably going to cause more problems than it solves so it is probably
better to just remove them.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Add an OSSL_ prefix onto STATEM

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

SSL_state has been replaced by SSL_get_state and SSL_set_state is no longer
supported.

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>

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Change various state machine functions to use the prefix ossl_statem
instead.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

The macros SSL_in_connect_init() and SSL_in_accept_init() inadvertently
depended on SSL structure internals. This fixes it to use public API calls
instead.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Rename the enum HANDSHAKE_STATE to OSSL_HANDSHAKE_STATE to ensure there are
no namespace clashes, and convert it into a typedef.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Fixed some issues in the logic for determining whether an SKE should be
expected or not. In particular only allow an SKE for RSA if its export and
the key size is not allowed. Also fix the ephemeral ciphersuite checks and
add in a missing call to ssl3_check_cert_and_algorithm().

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Update the return type for SSL_state in the documentation.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Update the CHANGES file for the state machine rewrite

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

s_server was (ab)using SSL_set_state to force a renegotiation. This is a
bad way to do things and does not work with the new state machine code, so
we need to do it a different way.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Fix an out of date reference to old state machine code in a comment

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>

Add some documentation on the thinking behind the state machine.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

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>

The DTLSv1_listen code set the state value explicitly to move into init.
Change to use state_set_in_init() instead.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

ssl.h and ssl3.h have a number of defines for the various states in the old
state machine code. Since this is public API it is not desirable to just
remove them. Instead redefine them to the closest equivalent state in the
new state machine code. If an application calls SSL_state then the return
value can still be compared against these old values if necessary. However
not all values have an equivalent state in the new code, so these are just
redefined to a dummy value.

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>

Implement all of the necessary changes for moving TLS server side
processing into 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>

Remove redundant code following moving client side TLS handling to the new
state machine implementation.

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>

Signed-off-by: Kurt Roeckx <kurt@roeckx.be>
Reviewed-by: Rich Salz <rsalz@akamai.com>

MR #1276, RT #4107