2 Commits

Author SHA1 Message Date
Matt Caswell
8723588e1b Implement Client TLS state machine
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>
2015-10-30 08:32:44 +00:00
Matt Caswell
f8e0a55738 Add initial state machine rewrite code
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>
2015-10-30 08:27:59 +00:00