Adapted from BoringSSL. Added a test.

The extension parsing code is already attempting to already handle this for
some individual extensions, but it is doing so inconsistently. Duplicate
efforts in individual extension parsing will be cleaned up in a follow-up.
Reviewed-by: NStephen Henson <steve@openssl.org>

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

To enable heartbeats for DTLS, configure with enable-heartbeats.
Heartbeats for TLS have been completely removed.

This addresses RT 3647
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

If init failed we'd like to set an error code to indicate that. But if
init failed then when the error system tries to load its strings its going
to fail again. We could get into an infinite loop. Therefore we just set
a single error the first time around. After that no error is set.
Reviewed-by: NRich Salz <rsalz@openssl.org>

The new init functions can fail if the library has already been stopped. We
should be able to indicate failure with a 0 return value.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Man, there were a lot of renamings :)
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Building on the pervious commit to auto initialise and de-initialise libssl
Reviewed-by: NRichard Levitte <levitte@openssl.org>

This commit provides the basis and core code for an auto initialisation
and deinitialisation framework for libcrypto and libssl. The intention is
to remove the need (in many circumstances) to call explicit initialise and
deinitialise functions. Explicit initialisation will still be an option,
and if non-default initialisation is needed then it will be required.
Similarly for de-initialisation (although this will be a lot easier since
it will bring all de-initialisation into a single function).
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Deprecate undocumented SSL_cache_hit(). Make SSL_session_reused() into a
real function.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Previous commit 7bb196a7 attempted to "fix" a problem with the way
SSL_shutdown() behaved whilst in mid-handshake. The original behaviour had
SSL_shutdown() return immediately having taken no action if called mid-
handshake with a return value of 1 (meaning everything was shutdown
successfully). In fact the shutdown has not been successful.

Commit 7bb196a7 changed that to send a close_notify anyway and then
return. This seems to be causing some problems for some applications so
perhaps a better (much simpler) approach is revert to the previous
behaviour (no attempt at a shutdown), but return -1 (meaning the shutdown
was not successful).

This also fixes a bug where SSL_shutdown always returns 0 when shutdown
*very* early in the handshake (i.e. we are still using SSLv23_method).
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

The DTLSv1_listen function exposed details of the underlying BIO
abstraction and did not properly allow for IPv6. This commit changes the
"peer" argument to be a BIO_ADDR and makes it a first class function
(rather than a ctrl) to ensure proper type checking.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

PACKET contents should be read-only. To achieve this, also
- constify two user callbacks
- constify BUF_reverse.
Reviewed-by: NRich Salz <rsalz@openssl.org>

This was done by the following
        find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
        print unless $. == 1 && m@/\* .*\.[ch] \*/@;
        close ARGV if eof; # Close file to reset $.

And then some hand-editing of other files.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

The SSL and SSL_CTX structures are reference counted. However since libssl
was made opaque there is no way for users of the library to manipulate the
reference counts. This adds functions to enable that.
Reviewed-by: NStephen Henson <steve@openssl.org>

Calling SSL_shutdown while in init previously gave a "1" response, meaning
everything was successfully closed down (even though it wasn't). Better is
to send our close_notify, but fail when trying to receive one.

The problem with doing a shutdown while in the middle of a handshake is
that once our close_notify is sent we shouldn't really do anything else
(including process handshake/CCS messages) until we've received a
close_notify back from the peer. However the peer might send a CCS before
acting on our close_notify - so we won't be able to read it because we're
not acting on CCS messages!
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Reviewed-by: NDr. Stephen Henson <steve@openssl.org>

Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

It turns out that -pause calls the undocumented function SSL_set_debug.
That just sets flag inside the SSL structure.  That flag, despite
the command is never used.  So remove the flag, the field, and the
function.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

These now take and return unsigned long, and get is constified.
Updated related documentation and util/ssleay.num
Reviewed-by: NMatt Caswell <matt@openssl.org>

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

Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Provide backwards-compatiblity for functions, macros and include
files if OPENSSL_API_COMPAT is either not defined or defined less
than the version number of the release in which the feature was
deprecated.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

Don't define stacks in C source files: it causes warnings
about unused functions in some compilers.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Applications wishing to include their own stacks now just need to include

DEFINE_STACK_OF(foo)

in a header file.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

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

Also tweak some of the code in demos/bio, to enable interactive
testing of BIO_s_accept's use of SSL_dup.  Changed the sconnect
client to authenticate the server, which now exercises the new
SSL_set1_host() function.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

The protocol selection code is now consolidated in a few consecutive
short functions in a single file and is table driven.  Protocol-specific
constraints that influence negotiation are moved into the flags
field of the method structure.  The same protocol version constraints
are now applied in all code paths.  It is now much easier to add
new protocol versions without reworking the protocol selection
logic.

In the presence of "holes" in the list of enabled client protocols
we no longer select client protocols below the hole based on a
subset of the constraints and then fail shortly after when it is
found that these don't meet the remaining constraints (suiteb, FIPS,
security level, ...).  Ideally, with the new min/max controls users
will be less likely to create "holes" in the first place.
Reviewed-by: NKurt Roeckx <kurt@openssl.org>

Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

It served a purpose, but not any more.
Reviewed-by: NStephen Henson <steve@openssl.org>

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

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

Suggested by David Benjamin
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NViktor Dukhovni <openssl-users@dukhovni.org>

MR: #1520

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

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

This adds support for SSL/TLS configuration using configuration modules.
Sets of command value pairs are store and can be replayed through an
SSL_CTX or SSL structure using SSL_CTX_config or SSL_config.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Since auto ecdh is now always used SSL_OP_SINGLE_ECDH_USE is
redundant. Simplify associated code.
Reviewed-by: NRichard Levitte <levitte@openssl.org>