Implementation experience has shown that the original plan for async wait
fds was too simplistic. Originally the async logic created a pipe internally
and user/engine code could then get access to it via API calls. It is more
flexible if the engine is able to create its own fd and provide it to the
async code.

Another issue is that there can be a lot of churn in the fd value within
the context of (say) a single SSL connection leading to continually adding
and removing fds from (say) epoll. It is better if we can provide some
stability of the fd value across a whole SSL connection. This is
problematic because an engine has no concept of an SSL connection.

This commit refactors things to introduce an ASYNC_WAIT_CTX which acts as a
proxy for an SSL connection down at the engine layer.

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

VisualStudio 2015 has a bug where an internal compiler error was occurring.
By reordering the DEFINE_STACK_OF declarations for SSL_CIPHER and SSL_COMP
until after the ssl3.h include everything seems ok again.

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

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

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

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Fix "mixed declarations and code" warnings.
Use OpenSSL headers.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Stephen Henson <steve@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Add X25519 to TLS supported curve list.
Reject attempts to configure keys which cannot be used
for signing.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Check sign/verify blocked with X25519

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Add a flag to EC_METHOD for curves which do not support signing.
New function EC_KEY_can_sign() returns 1 is key can be used for signing.
Return an explicit error is an attempt is made to sign with
no signing curves.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

In some cases the EC_POINT and EC_KEY BIGNUM components are suboptimal
or inappropriate. Add an "custom_data" field which curves can populate with
a custom structure to suit their needs.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Extract compression form in EC_KEY_oct2key() instead of manually in the
ASN.1 code. For custom curves do not assume the initial octet is the
compression form: it isn't for X25519 et al.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Add support for optional overrides of various private key operations
in EC_METHOD.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Extend EC_METHOD to permit additional customisation of private key and
ECDH operations.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Use standard X25519 and X448 names for OIDs. Delete EdDSA OIDs: for now they
wont be used and EdDSA may use a different format.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Emilia Käsper <emilia@openssl.org>

Signed-off-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>

Removing certs broke the mk1mf build.

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

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

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

Exiting out of a recipe more than necessary leaves an ugly message.

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

When building with GNU C, clang or VMS C, it's more efficient to
generate dependency file and object file in one call rather than two.
Have the dependency output in a temporary file and compare it with the
previous one if available to see if replacement is waranted, thereby
avoiding unnecessary reconstruction of Makefile / descrip.mms.

Github issue #750

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

Stack Overflow has a number of questions related to mutual authentication,
the client and its certificate. Those visiting the man pages for functions
like SSL_CTX_use_certificate and SSL_CTX_load_verify_locations don't
receive the benefit of a cross reference to SSL_CTX_set_client_CA_list.

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

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>

- srtp_profiles variable is defined when building with SRTP, keeping
the variable usage also under ifndef OPENSSL_NO_SRTP
- alpn help option was kept under ifndef OPENSSL_NO_SRTP

Reviewed-by: Kurt Roeckx <kurt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>

The INCLUDE statement can handle setting extra include directories for
individual object files, let's use it.

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

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

Even though AVX support was added in GAS 2.19 vpclmulqdq was apparently
added in 2.20.

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

RT#4323

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

Add some missing parentheses and reformat.

Document EC_KEY_oct2key(), EC_KEY_key2buf(), EC_KEY_oct2priv(),
EC_KEY_priv2oct() and EC_KEY_priv2buf()

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

Now that BIO_sock_nbio is available, use it in the apps.

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

I read the PROBLEMS, and they're outdated; nothing I'd put in the
online FAQ, for example.  Test-builds work without using these files.
Had to remove the rehash.time stuff from Makefile.in

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

We don't want recipes for the same files generated more than once

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