Fix leaks in priv_encode_gost()

Issues/174

This `if' statement is redundant since ce40d60d ("Bugfix.")

get_gost_engine_param() have no side effects and `param' is set to
`gost_cipher_list' only if already equal to `gost_cipher_list'.

`param' is used unconditionally in pkey_GOST_ECcp_encrypt() so we can
unconditionally check (vs in any particular `if' branch) for it's being
non-NULL. This is similar to how pkey_GOST_ECcp_decrypt() works with
`param'.

Closes #174.

Fixes #180

Fixes #178

Add support for NID_id_tc26_gost_3410_2012_512_paramSetTest

Add support for 512-bit curve parameters.

Signed-off-by: Dmitry Eremin-Solenikov <dbaryshkov@gmail.com>

Fixes for Scan 20190918

Calling EC_POINT_get_affine_coordinates() without checking
return value.
Some fixes for Coverity Scan from issue #174.

Unchecked return value (CHECKED_RETURN)
Some fixes for Coverity Scan from issue #174.

Fix compilation with Microsoft Visual C.

For Grasshopper OMAC_ACPKM, OMAC and MAGMA, support XOF

XOF (eXtendable-Output Function) is supported in OpenSSL since version
1.1.1.  Unfortunately, that support is limited, as it requires calling
EVP_DigestFinalXOF().  However, the grasshopper code wasn't compatible.

This changeset adds XOF support in grasshopper

This changeset removes the _meth_ calls from test_grasshopper.c (they
should never have been there, but considering support for XOF came so
late in OpenSSL, their presence is understandable) and uses supported
functionality for this sort of thing instead.

Cleanup tests

It's set correctly when these tests are started with ctest, and
otherwise, we leave it to the user to decide.  Either way, we set it
to a bogus value when it isn't previously set...

An OPENSSL_CONF from the user may cause trouble

test/run_tests: when ctest is verbose, make TAP::Harness verbose too

test/run_tests: extend support for more operating systems

Not all systems recognise LD_LIBRARY_PATH, and we therefore need to
set other environment variables.

Currently set:

- LD_LIBRARY_PATH (Linux and ELF HP-UX)
- DYLD_LIBRARY_PATH (MacOS X)
- LIBPATH (AIX, OS/2)

More can be added as the need arises.

Fixes #146

test/run_tests: Always set paths when OPENSSL_ROOT_DIR is defined

That will add the pkg-config on FreeBSD

When the environment variable OPENSSL_ROOT_DIR is defined, we need to
ensure that PATH and LD_LIBRARY_PATH are properly affected.

This is a little bit complicated, since OPENSSL_ROOT_DIR could point
at an OpenSSL build directory as well as an OpenSSL installation
tree.  Fortunately, it's easy to detect the difference; if it's a
build tree, there's a sub-directory 'apps'.

For installation trees, it's further complicated by OpenSSL's
'multilib' target attribute, which exists for platforms that support
directory separated libraries for differing bitness (typically 32-bit
and 64-bit libraries).  We trust pkg-config to give us the answer.
Binaries are easier, they live in $OPENSL_ROOT_DIR/bin.

Fixes #146

gost_pmeth.c: mitigate for constness difference in copy function

The second argument for the pkey_copy function has been constified in
OpenSSL to be 3.0.  This is normally not a problem, but when passing a
pointer to such a function, the compiler does complain.

This change solves the issue by looking at the macros
OPENSSL_VERSION_MAJOR, which is new in OpenSSL to be 3.0, and set
constness based on that.

Fixes #154

travis-ci: add linux-ppc64le build