DJGPP is no longer a supported platform.  Remove all #ifdef, etc.,
cases that refer to it.  DJGPP also #define'd WATT32, so that
is now removed as well.

The options which emulate a web server don't make sense when doing DTLS.
Exit with an error if an attempt is made to use them.

PR#3453

PR#3445

Remove RFC5878 code. It is no longer needed for CT and has numerous bugs

Add -trusted_first description to help messages and man pages
of tools that deal with certificate verification.

The "-unix <path>" argument allows s_server and s_client to use a unix
domain socket in the filesystem instead of IPv4 ("-connect", "-port",
"-accept", etc). If s_server exits gracefully, such as when "-naccept"
is used and the requested number of SSL/TLS connections have occurred,
then the domain socket file is removed. On ctrl-C, it is likely that
the stale socket file will be left over, such that s_server would
normally fail to restart with the same arguments. For this reason,
s_server also supports an "-unlink" option, which will clean up any
stale socket file before starting.

If you have any reason to want encrypted IPC within an O/S instance,
this concept might come in handy. Otherwise it just demonstrates that
there is nothing about SSL/TLS that limits it to TCP/IP in any way.

(There might also be benchmarking and profiling use in this path, as
unix domain sockets are much lower overhead than connecting over local
IP addresses).
Signed-off-by: NGeoff Thorpe <geoff@openssl.org>

Signed-off-by: NGeoff Thorpe <geoff@openssl.org>

Add a debugging security callback option to s_client/s_server. This will
print out each security parameter as it is accepted or rejected.

Add auto DH parameter support. This is roughly equivalent to the
ECDH auto curve selection but for DH. An application can just call

SSL_CTX_set_auto_dh(ctx, 1);

and appropriate DH parameters will be used based on the size of the
server key.

Unlike ECDH there is no way a peer can indicate the range of DH parameters
it supports. Some peers cannot handle DH keys larger that 1024 bits for
example. In this case if you call:

SSL_CTX_set_auto_dh(ctx, 2);

Only 1024 bit DH parameters will be used.

If the server key is 7680 bits or more in size then 8192 bit DH parameters
will be used: these will be *very* slow.

The old export ciphersuites aren't supported but those are very
insecure anyway.

(cherry picked from commit 1f44dac24d1cb752b1a06be9091bb03a88a8598e)

Whitespace fixes

If multiple TLS extensions are expected but not received, the TLS extension and supplemental data 'generate' callbacks are the only chance for the receive-side to trigger a specific TLS alert during the handshake.

Removed logic which no-op'd TLS extension generate callbacks (as the generate callbacks need to always be called in order to trigger alerts), and updated the serverinfo-specific custom TLS extension callbacks to track which custom TLS extensions were received by the client, where no-ops for 'generate' callbacks are appropriate.

PR#3106

Conflicts:
	apps/s_server.c

Free generated supp data after handshake completion, add comment regarding use of num_renegotiations in TLS and supp data generation callbacks

Add callbacks supporting generation and retrieval of supplemental data entries, facilitating RFC 5878 (TLS auth extensions)
Removed prior audit proof logic - audit proof support was implemented using the generic TLS extension API
Tests exercising the new supplemental data registration and callback api can be found in ssltest.c.
Implemented changes to s_server and s_client to exercise supplemental data callbacks via the -auth argument, as well as additional flags to exercise supplemental data being sent only during renegotiation.

This change adds support for ALPN[1] in OpenSSL. ALPN is the IETF
blessed version of NPN and we'll be supporting both ALPN and NPN for
some time yet.

[1] https://tools.ietf.org/html/draft-ietf-tls-applayerprotoneg-00

Conflicts:
	ssl/ssl3.h
	ssl/t1_lib.c

Contributed by Trevor Perrin.

Add new methods DTLS_*_method() which support both DTLS 1.0 and DTLS 1.2 and
pick the highest version the peer supports during negotiation.

As with SSL/TLS options can change this behaviour specifically
SSL_OP_NO_DTLSv1 and SSL_OP_NO_DTLSv1_2.

Add correct flags for DTLS 1.2, update s_server and s_client to handle
DTLS 1.2 methods.

Currently no support for version negotiation: i.e. if client/server selects
DTLS 1.2 it is that or nothing.

Just a sample, real world applications would have to be cleverer.

Add new verify options to set checks.

Remove previous -check* commands from s_client and s_server.

Add support for separate verify and chain stores in s_client.