Merge find-undoc-api into find-doc-nits

Use \b on NOEXIST and EXPORT_VAR_AS_FUNC patterns as suggested by Andy.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1912)

Move SCT_LIST_free definition into a more logical place

This reflects its position in include/openssl/ct.h.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

Make sure things get deleted when test setup fails in ct_test.c

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

Use valid signature in test_decode_tls_sct()

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

Pass a temporary pointer to o2i_SCT_signature from SCT_new_from_base64

Otherwise, |dec| gets moved past the end of the signature by
o2i_SCT_signature and then can't be correctly freed afterwards.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

Subtract padding from outlen in ct_base64_decode

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

Construct SCT from base64 in ct_test

This gives better code coverage and is more representative of how a
user would likely construct an SCT (using the base64 returned by a CT log).

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1548)

On x86 machines where the compiler supports -m32, use 'linux-x86'

The rationale is that the linux-x86 is the most likely config target
to evolve and should therefore be chosen when possible, while
linux-elf is mostly reserved for older Linux machines.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1924)

Add a modern linux-x86 config target

'linux-x86' is similar to 'linux-x86_64' but uses -m32 rather than -m64.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1924)

Fix a "defined but not used" warning when enabling ssl-trace

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

Remove a hack from ssl_test_old

ssl_test_old was reaching inside the SSL structure and changing the internal
BIO values. This is completely unneccessary, and was causing an abort in the
test when enabling TLSv1.3.

I also removed the need for ssl_test_old to include ssl_locl.h. This
required the addition of some missing accessors for SSL_COMP name and id
fields.

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

Add SSL_peek() and SSL_peek_ex() to NAME section

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

Fix a typo in a comment

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

Move getting the curvelist for client and server out of the loop

No need to continually get the list of supported curves for the client
and server. Just do it once.

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

Fixed various style issues in the key_share code

Numerous style issues as well as references to TLS1_3_VERSION instead of
SSL_IS_TLS13(s)

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

Add some tests for the key_share extension

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

Check key_exchange data length is not 0

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

Ensure the whole key_share extension is well formatted

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

Validate that the provided key_share is in supported_groups

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

Start using the key_share data to derive the PMS

The previous commits put in place the logic to exchange key_share data. We
now need to do something with that information. In <= TLSv1.2 the equivalent
of the key_share extension is the ServerKeyExchange and ClientKeyExchange
messages. With key_share those two messages are no longer necessary.

The commit removes the SKE and CKE messages from the TLSv1.3 state machine.
TLSv1.3 is completely different to TLSv1.2 in the messages that it sends
and the transitions that are allowed. Therefore, rather than extend the
existing <=TLS1.2 state transition functions, we create a whole new set for
TLSv1.3. Intially these are still based on the TLSv1.2 ones, but over time
they will be amended.

The new TLSv1.3 transitions remove SKE and CKE completely. There's also some
cleanup for some stuff which is not relevant to TLSv1.3 and is easy to
remove, e.g. the DTLS support (we're not doing DTLSv1.3 yet) and NPN.

I also disable EXTMS for TLSv1.3. Using it was causing some added
complexity, so rather than fix it I removed it, since eventually it will not
be needed anyway.

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

Add a TLS version consistency check during session resumption

This is a temporary fix for while we are still using the old session
resumption logic in the TLSv1.3 code. Due to differences in EXTMS support
we can't resume a <=TLSv1.2 session in a TLSv1.3 connection (the EXTMS
consistency check causes the connection to abort). This causes test
failures.

Ultimately we will rewrite the session resumption logic for TLSv1.3 so this
problem will go away. But until then we need a quick fix to keep the tests
happy.

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

Add processing of the key_share received in the ServerHello

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

Add key_share info to the ServerHello

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

Update the trace code to know about the key_share extension

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

Add the key_share processing to the server side

At the moment the server doesn't yet do anything with this information.
We still need to send the server's key_share info back to the client. That
will happen in subsequent commits.

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

Generate the key_shares extension on the client side

In this commit we just generate the extension on the client side, but don't
yet do anything with it. Subsequent commits, will add the server side
capability.

At the moment we hard code a single key_share. In the future we should make
this configurable.

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

Check return value of some BN functions.

Factorise multiple bn_get_top(group->field) calls
Add missing checks on some conditional BN_copy return value
Add missing checks on some BN_copy return value
Add missing checks on a few bn_wexpand return value

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1626)

Introduce PATH_MAX and NAME_MAX

 to define the certificate filename storage buffer.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1569)

Simplify and fix usage of three string array variable...

 using two separated local variables.

buf[1] was unused.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1569)

Add test for CT_POLICY_EVAL_CTX default time

Checks that the epoch_time_in_ms field of CT_POLICY_EVAL_CTX is initialized
to approximately the current time (as returned by time()) by default. This
prevents the addition of this field, and its verification during SCT
validation, from breaking existing code that calls SCT_validate directly.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Convert C++ comments to C-style comments

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Cast time_t to uint64_t before converting to milliseconds in ct_policy.c

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

By default, allow SCT timestamps to be up to 5 minutes in the future

As requested in
https://github.com/openssl/openssl/pull/1554#issuecomment-246371575.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Don't check for time() failing in CT_POLICY_EVAL_CTX_new

See https://github.com/openssl/openssl/pull/1554#issuecomment-246354677.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Default CT_POLICY_EVAL_CTX.epoch_time_in_ms to time()

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Reword documentation for {SCT_CTX/CT_POLICY_EVAL_CTX}_set_time

Do not call the time "current", as a different time can be provided.
For example, a time slightly in the future, to provide tolerance for
CT logs with a clock that is running fast.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Remove obsolete error constant CT_F_CTLOG_NEW_NULL

ctlog_new_null() no longer exists.

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Check that SCT timestamps are not in the future

Reviewed-by: Viktor Dukhovni <viktor@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1554)

Only build the body of e_padlock when there are lower level routines

engines/e_padlock.c assumes that for all x86 and x86_64 platforms, the
lower level routines will be present.  However, that's not always
true, for example for solaris-x86-cc, and that leads to build errors.

The better solution is to have configure detect if the lower level
padlock routines are being built, and define the macro PADLOCK_ASM if
they are, and use that macro in our C code.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1510)

Make it possible to disable building and running tests

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1514)

Revert "Remove heartbeats completely"

Done too soon, this is for future OpenSSL 1.2.0

This reverts commit 6c62f9e1639a7d1a879f363a99882920104dfedb.

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

Remove heartbeats completely

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1669)

Simplify PKCS#12 PBE algorithm.

Simplify PKCS#12 PBE algorithm by working out Ij + B + 1 directly
instead of using BIGNUMs.

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

Add a warning stipulating how things should be coded in ossl_init_base

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1922)

Stop init loops

Under certain circumstances, the libcrypto init code would loop,
causing a deadlock.  This would typically happen if something in
ossl_init_base() caused an OpenSSL error, and the error stack routines
would recurse into the init code before the flag that ossl_init_base()
had been run was checked.

This change makes sure ossl_init_base isn't run once more of the base
is initiated.

Thanks to Dmitry Kostjuchenko for the idea.

Fixes Github issue #1899

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1922)

Configurations/10-main.conf: remove obsolete flag from solaris-x86-gcc.

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

Configurations/10-main.conf: document GCC for Solaris config constraint.

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

Allow CA.pl script user to pass extra arguments to openssl command

Useful e.g. to fully script CA commands

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1797)

dsa/dsa_gen: add error message for seed_len < 0

prio openssl 1.1.0 seed_len < q was accepted and the seed argument was
then ignored. Now DSA_generate_parameters_ex() returns an error in such
a case but no error string.

Signed-off-by: Sebastian Andrzej Siewior <sebastian@breakpoint.cc>
Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1657)

Revert "Fixed deadlock in CRYPTO_THREAD_run_once for Windows"

This reverts commit 349d1cfddcfa33d352240582a3803f2eba39d9a0.

The proposed fix is incorrect. It marks the "run_once" code as having
finished before it has. The intended semantics of run_once is that no
threads should proceed until the code has run exactly once. With this
change the "second" thread will think the run_once code has already been
run and will continue, even though it is still in progress. This could
result in a crash or other incorrect behaviour.

Reviewed-by: Tim Hudson <tjh@openssl.org>

Remove heartbeat support

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1669)

Fixed deadlock in CRYPTO_THREAD_run_once for Windows

Fixed deadlock in CRYPTO_THREAD_run_once() if call to init() is causing
a recursive call to CRYPTO_THREAD_run_once() again that is causing a hot
deadloop inside do { } while (result == ONCE_ININIT); section.

CLA: trivial
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1913)

Solution proposal for issue #1647.

Avoid a memory alignment issue.

Signed-off-by: Matthias Kraft <Matthias.Kraft@softwareag.com>
CLA: trivial
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1650)

Update s_client and s_server documentation about some missing arguments

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1837)

Replace the 'SSL' broken link with SSL_CTX_set_security_level which seems not being referenced from elsewhere

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1898)

EVP docs: chacha20, chacha20-poly1305

CLA: trivial

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1909)

Update fuzz corpora

New minimal fuzz corpora set

Reviewed-by: Andy Polyakov <appro@openssl.org>
GH: #1910

Cast to an unsigned type before negating

llvm's ubsan reported:
runtime error: negation of -9223372036854775808 cannot be represented in
type 'int64_t' (aka 'long'); cast to an unsigned type to negate this
value to itself

Found using libfuzzer

Reviewed-by: Rich Salz <rsalz@openssl.org>
GH: #1908

sha/asm/sha512-armv8.pl: add NEON version of SHA256.

This provides up to 30% better performance on some of recent processors.

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

sha/keccak1600.c: add some optimized implementations.

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

chacha/asm/chacha-x86.pl: improve [backward] portability.

In order to minimize dependency on assembler version a number of
post-SSE2 instructions are encoded manually. But in order to simplify
the procedure only register operands are considered. Non-register
operands are passed down to assembler. Module in question uses pshufb
with memory operands, and old [GNU] assembler can't handle it.
Fortunately in this case it's possible skip just the problematic
segment without skipping SSSE3 support altogether.

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

PPC assembler pack: add some PPC970/G5 performance data.

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

Fix typo in util/process_docs.pl

The links weren't properly terminated with a "

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1901)

Fix referenses in section 7 manuals

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1900)

Fix referenses in section 1 manuals

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1900)

Fix referenses in section 3 manuals

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1900)

Add util/check-doc-links.pl, to be used to check referenses in manuals

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1900)

Fix the effect of no-dso in crypto/init.c

When configured no-dso, there are no DSO_{whatever} macros defined.
Therefore, before checking those, you have to check if OPENSSL_NO_DSO
is defined.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1902)

Small fixups of util/process_docs.pl

- the pod path hadn't been changed with the directory layout change
- apparently, pod2html doesn't add ".html" at the end of links, making
  them useless, so we need to fix that

With thanks for the report to Michel <michel.sales@free.fr>

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1896)

Fix test_sslcorrupt when using TLSv1.3

The test loops through all the ciphers, attempting to test each one in turn.
However version negotiation happens before cipher selection, so with TLSv1.3
switched on if we use a non-TLSv1.3 compatible cipher suite we get "no
share cipher".

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

Revert "Move algorithm specific ppccap code from crypto/ppccap.c"

Now that we can link specifically with static libraries, the immediate
need to split ppccap.c (and eventually other *cap.c files) is no more.

This reverts commit e3fb4d3d52e188b83ccb8506aa2f16cb686f4d6c.

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

Rename the Elliptic Curves extension to supported_groups

This is a skin deep change, which simply renames most places where we talk
about curves in a TLS context to groups. This is because TLS1.3 has renamed
the extension, and it can now include DH groups too. We still only support
curves, but this rename should pave the way for a future extension for DH
groups.

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

Link internal tests with static OpenSSL libraries when needed

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1889)

Document how to force linking with static libraries

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1889)

Building: make it possible to force linking with static OpenSSL libs

Very simply, support having the .a extension to denote depending on
static libraries.  Note that this is not supported on native Windows
when building shared libraries, as there is not static library then,
just an import library with the same name.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1889)

Fix no-ct in test/ct_test.c

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1890)

descrip.mms.tmpl: Simplify fiddling of logical names record and statem

Instead of enumerating exactly those files in test/ that include
../ssl/ssl_locl.h, assume they all do.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1891)

Update CHANGES and NEWS

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

Fix the no-tls option

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

Fix no-cms (CVE-2016-7053)

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

test/evptests.txt: add negative tests for AEAD ciphers.

This is done by taking one vector, "corrupting" last bit of the
tag value and verifying that decrypt fails.

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

test: add TLS application data corruption test.

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

add test for CVE-2016-7053

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

Don't set choice selector on parse failure.

Don't set choice selector on parse failure: this can pass unexpected
values to the choice callback. Instead free up partial structure
directly.

CVE-2016-7053

Thanks to Tyler Nighswander of ForAllSecure for reporting this issue.

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

chacha20/poly1305: make sure to clear the buffer at correct position

The offset to the memory to clear was incorrect, causing a heap buffer
overflow.

CVE-2016-7054

Thanks to Robert Święcki for reporting this

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

aes/asm/aesp8-ppc.pl: improve [backward] portability.

Some of stone-age assembler can't cope with r0 in address. It's actually
sensible thing to do, because r0 is shunted to 0 in address arithmetic
and by refusing r0 assembler effectively makes you understand that.

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

bn/asm/x86_64-mont.pl: fix for CVE-2016-7055 (Low severity).

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

test/bntest.c: regression test for CVE-2016-7055.

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

Fix the evp_test Ctrl keyword processing

Skip the test if the value after ":" is a disabled algorithm, rather
than failing it

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

Fix no-dso (shlibloadtest)

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

Address some supported_versions review comments

Added some TODOs, refactored a couple of things and added a SSL_IS_TLS13()
macro.

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

Remove some redundant trace code

No need to have a supported versions table and a versions table. They
should be the same.

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

Fix some missing checks for TLS1_3_VERSION_DRAFT

There were a few places where we weren't checking to see if we were using
the draft TLS1.3 version or not.

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

Give the test with only TLS1.1 and TLS1.0 a better name

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

Add a TODO(TLS1.3) about renegotation

Renegotiation does not exist in TLS1.3, so we need to disable it at some
point.

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

Add some more version tests

Send a TLS1.4 ClientHello with supported_versions and get TLS1.3
Send a TLS1.3 ClientHello without supported_versions and get TLS1.2

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

A style tweak based on feedback received

Replace a bare ";" with "continue;" for the body of a for loop.

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

Look at the supported_versions extension even if the server <TLS1.3

If supported_versions is present it takes precedence.

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

Ensure that vent->smeth != NULL before we call vent->smeth()

We can end up with a NULL SSL_METHOD function if a method has been
disabled. If that happens then we shouldn't call vent->smeth().

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

Address some review feedback comments for supported_versions

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