Check for zero records and return immediately

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2822)

appveyor.yml: streamline pull requests.

For pull requests not tagged with [extended tests]:

- short-curcuit most expensive fuzz and install tests;
- skip over non-shared builds;

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2810)

Configurations/50-masm.conf: add /nologo to ml64 command line.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2810)

Add NOTES.UNIX, with a description on how to deal with runpaths

[skip ci]

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2818)

Check that async_jobs is not negative and not too high.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2693)

Code health: ssl/ssl_locl.h unused macros

CLA: trivial

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2806)

VMS: compensate for gmtime_r() parameter pointer size

With VMS C, the second parameter takes a 32-bit pointer.  When
building with 64-bit pointer size default, we must compensate.

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2811)

Don't use deprecated EVP_CIPHER_CTX_cleanup() internally

Use EVP_CIPHER_CTX_reset() instead

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2812)

Remove some obsolete/obscure internal define switches:

- FLAT_INC
- PKCS1_CHECK (the SSL_OP_PKCS1_CHECK options have been
  no-oped)
- PKCS_TESTVECT (debugging leftovers)
- SSL_AD_MISSING_SRP_USERNAME (unfinished feature)
- DTLS_AD_MISSING_HANDSHAKE_MESSAGE (unfinished feature)
- USE_OBJ_MAC (note this removes a define from the public header but
   very unlikely someone would be depending on it)
- SSL_FORBID_ENULL

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

Remove OPENSSL_indirect_call()

It's undocumented and unused in the tree.  The idea seems to have
never gained much traction, and can be removed without breaking
ABI compatibility.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2800)

Don't free in cleanup routine

Cleanse instead, and free in the free routine.

Seems to have been introduced in commit
846ec07d904f9cc81d486db0db14fb84f61ff6e5 when EVP_CIPHER_CTX was made
opaque.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2798)

crypto/des: remove unreferenced rcp_enc.c module.

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

Code health: Remove base address setting for mingw

Base address setting was done for the sake of FIPS.  Since FIPS references
have been removed, we clean away this one as well.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2791)

Fix handling of EVP_PKEY_CTRL_PKCS7_ENCRYPT/DECRYPT with OPENSSL_NO_CMS.

Reviewed-by: Stephen Henson <steve@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2764)

Add AGL's "beer mug" PEM file as another test input

AGL has a history of pointing out the idiosynchronies/laxness of the
openssl PEM parser in amusing ways.  If we want this functionality to
stay present, we should test that it works.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2756)

Add test corpus for PEM reading

Generate a fresh certificate and DSA private key in their respective PEM
files.  Modify the resulting ASCII in various ways so as to produce input
files that might be generated by non-openssl programs (openssl always
generates "standard" PEM files, with base64 data in 64-character lines
except for a possible shorter last line).

Exercise various combinations of line lengths, leading/trailing
whitespace, non-base64 characters, comments, and padding, for both
unencrypted and encrypted files.  (We do not have any other test coverage
that uses encrypted files, as far as I can see, and the parser enforces
different rules for the body of encrypted files.)

Add a recipe to parse these test files and verify that they contain the
expected string or are rejected, according to the expected status.
Some of the current behavior is perhaps suboptimal and could be revisited.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2756)

Code health: Quick note in changes and the OPENSSL_GLOBAL et al changes

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2785)

Code health: With the VAX C-ism gone, OPENSSL_GLOBAL can be removed too

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2785)

Code health: Remove another VAX C-ism, globaldef and globalref

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2785)

Code health: make update

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2793)

Code health: Remove VAX exceptions in util/mkdef.pl

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2793)

Code health: Remove unused VAX transfer vector for engines

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2793)

Exdata test was never enabled.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2787)

Remove memcpy unrolling in bn_lib.c

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

Remove support for HMAC_TEST_PRIVATE_KEY_FORMAT

This is a bogus, undocumented format that was intended for testing; I
don't think anyone is using it.

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

Remove GENCB_TEST compile flag

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2790)

Fix test_ssl_new when compiled with no-tls1_2 or no-dtls1_2

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2788)

Fix sslapitest when compiled with no-tls1_2

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2788)

Revert rc4test removal, it performs additional tests not in evptests.txt

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2789)

Remove some commented out code in the tests

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2774)

Remove some commented out code in libssl

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2774)

Remove some commented out code in libcrypto

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2774)

Remove some commented out code in the apps

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2774)

Remove more redundant tests: md4, md5, rmd, rc4, p5_crpt2

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2784)

Remove a pointless "#ifndef" from bf_enc.c

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2778)

Remove bf_cbc.c

It is never built and the code is duplicated in bf_enc.c.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2778)

Update year, wording tweak

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2755)

Remove the file r160test.c

It is empty and is not compiled

Reviewed-by: Andy Polyakov <appro@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2777)

Remove wp_test.c: exactly the same tests are in evptests.txt

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2783)

Remove dead code in bn

There are a number of symbols in bn which are internal only and never used
by anything. They should be removed.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2766)

Remove some #if 0 code in ssl, crypto/bio

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2781)

Code health: Stop using timeb.h / ftime() (VMS only)

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2775)

Code health: Remove obvious VAX C fixups

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2775)

More Configure cleanup. Remove
- util/incore
- util/fipslink.pl
- the unused "baseaddr" configure switch

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

Clean up references to FIPS

This removes the fips configure option. This option is broken as the
required FIPS code is not available.

FIPS_mode() and FIPS_mode_set() are retained for compatibility, but
FIPS_mode() always returns 0, and FIPS_mode_set() can only be used to
turn FIPS mode off.

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

Remove BN_DEBUG_TRIX

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

Remove debugging leftovers in apps/opt.c

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

Avoid buffer underflow in evp_test.

The second loop in the remove_space function doesn't check for walking
back off of the start of the string while setting white space to 0.

This fix exits this loop once the pointer is before the (updated) beginning
of the string.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2752)

Remove unnecessary memset after PR #2583 avoids accessing
the uninitialized session_id now.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2608)

Move the CHIL engine to demos/engines

Moving out of the way, Makefile to be added

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2780)

Remove some dead code from libssl

There are a small number of functions in libssl that are internal only
and never used by anything.

Reviewed-by: Emilia Käsper <emilia@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2770)

Code cleanup: remove the VMS specific reimplementation of gmtime

This reimplementation was necessary before VMS C V7.1.  Since that's
the minimum version we support in this OpenSSL version, the
reimplementation is no longer needed.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2762)

Remove dead code in crypto/pkcs7

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

Remove methtest.c

This file tests code that doesn't exist.

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

Remove ancient demoCA directory

Reviewed-by: Tim Hudson <tjh@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2760)

Renumber to avoid a error code clash

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2758)

Trace support for TLS 1.3 certificate request message

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2728)

Initial incomplete TLS 1.3 certificate request support.

This adds partial support for TLS 1.3 certificate request message.

The request context and extensions are currently ignored on receive
and set to zero length on send.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2728)

Adjust the default value of the private key size

...in the man page to reflect the actual default (2048 instead of 512)

CLA: trivial
Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2754)

poly1305/asm/poly1305-x86_64.pl: minor AVX512 optimization.

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

crypto/x86_64cpuid.pl: add CFI annotations.

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

whrlpool/asm/wp-x86_64.pl: add CFI annotations.

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

camellia/asm/cmll-x86_64.pl: add CFI annotations.

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

poly1305/asm/poly1305-x86_64.pl: add CFI annotations.

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

chacha/asm/chacha-x86_64.pl: add CFI annotations.

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

Add missing blank lines and cosmetic improvements

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

TLS 1.3 support for ssl_print_ticket()

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

print out alpn extension

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Add ffdhe groups to trace output

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Print numerical value of named roups

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Add entry for PSK extension

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Add trace entries for remaining TLS 1.3 ciphersuites

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Print signature type to out, not bio_err

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2747)

Add a null UI method

There are cases when, if you pass a NULL UI_METHOD, the called
function will use an internal default.  This is well and good, but
there may be cases when this is undesirable and one would rather send
in a UI that does absolutely nothing (sort of a /dev/null).  UI_null()
is the UI_METHOD for this purpose.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2744)

poly1305/asm/poly1305-x86_64.pl: add VPMADD52 code path.

This is initial and minimal single-block implementation.

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

poly1305/asm/poly1305-x86_64.pl: switch to vpermdd in table expansion.

Effectively it's minor size optimization, 5-6% per affected subroutine.

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

poly1305/asm/poly1305-x86_64.pl: optimize AVX512 code path.

On pre-Skylake best optimization strategy was balancing port-specific
instructions, while on Skylake minimizing the sheer amount appears
more sensible.

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

Add tests for SHA1 and EC point compression

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2739)

For TLS 1.3 reject SHA1 TLS signatures

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2739)

Reject compressed point format with TLS 1.3

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2739)

EC certificate with compression point

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2739)

Add SuiteB support to tls_choose_sigalg()

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2738)

Add Suite B tests

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2738)

Add P-384 root and P-384, P-256 EE certificates.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2738)

X509 time: tighten validation per RFC 5280

- Reject fractional seconds
- Reject offsets
- Check that the date/time digits are in valid range.
- Add documentation for X509_cmp_time

GH issue 2620

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

.travis.yml: introduce concept of "extended tests"

Since CI is engaged on per merge request basis, it can be wasteful to
run each request through all the tests, especially those resource
consuming. Idea is to mark most of tests as "extended" and provide a
way to opt-in by marking last commit with [extended tests] tag. It's
still not as optimal as one could wish, as decision to skip a test
still requires machine time, and it's taken in configured environment,
i.e. with updates and additional packages installed...

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2292)

.travis.yml: make package pulls conditional.

Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2292)

Add -Wundef to --strict-warnings options.

Avoid a -Wundef warning in refcount.h
Avoid a -Wundef warning in o_str.c
Avoid a -Wundef warning in testutil.h
Include internal/cryptlib.h before openssl/stack.h
to avoid use of undefined symbol OPENSSL_API_COMPAT.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2712)

Tidy up certificate type handling.

The certificate types used to be held in a fixed length array or (if
it was too long) a malloced buffer. This was done to retain binary
compatibility. The code can be simplified now SSL is opaque by always
using a malloced buffer.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2733)

Increase the size of the stack buffer to prevent an overflow.

Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2721)

Fix potential memory leak in ASN1_TIME_to_generalizedtime()

If ret is allocated, it may be leaked on error.

Reviewed-by: Tim Hudson <tjh@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2666)

Fix duplicate error codes

Reviewed-by: Matt Caswell <matt@openssl.org>
GH: #2732

Implement SSL_read_ex() and SSL_write_ex() as documented.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
GH: #1964

Add an sslapitest for early callback

Make sure that we can stop handshake processing and resume it later.
Also check that the cipher list and compression methods are sane.
Unfortunately, we don't have the client-side APIs needed to force
a specific (known) session ID to be sent in the ClientHello, so
that accessor cannot be tested here.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Let test handshakes stop on certain errors

Certain callback APIs allow the callback to request async processing
by trickling a particular error value up the stack to the application
as an error return from the handshake function.  In those cases,
SSL_want() returns a code specific to the type of async processing
needed.

The create_ssl_connection() helper function for the tests is very
helpful for several things, including creating API tests.  However,
it does not currently let us test the async processing functionality
of these callback interfaces, because the special SSL error codes
are treated as generic errors and the helper continues to loop until
it reaches its maximum iteration count.

Add a new parameter, 'want', that indicates an expected/desired
special SSL error code, so that the helper will terminate when
either side reports that error, giving control back to the calling
function and allowing the test to proceed.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Use correct variable in test diagnostic

create_ssl_connection() prints out the results if SSL_accept() and/or
SSL_connect() fail, but was reusing the client return value when printing
about SSL_accept() failures.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Adopt test to changed behavior

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Tests for SSL early callback

Plumb things through in the same place as the SNI callback, since
we recommend that the early callback replace (and supplement) the
SNI callback, and add a few test cases.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Add SSL_CTX early callback

Provide a callback interface that gives the application the ability
to adjust the nascent SSL object at the earliest stage of ClientHello
processing, immediately after extensions have been collected but
before they have been processed.

This is akin to BoringSSL's "select_certificate_cb" (though it is not
API compatible), and as the name indicates, one major use is to examine
the supplied server name indication and select what certificate to
present to the client.  However, it can also be used to make more
sweeping configuration changes to the SSL object according to the
selected server identity and configuration.  That may include adjusting
the permitted TLS versions, swapping out the SSL_CTX object (as is
traditionally done in a tlsext_servername_callback), changing the
server's cipher list, and more.

We also wish to allow an early callback to indicate that it needs to perform
additional work asynchronously and resume processing later.  To that effect,
refactor the second half of tls_process_client_hello() into a subroutine to be
called at the post-processing stage (including the early callback itself), to
allow the callback to result in remaining in the same work stage for a later
call to succeed.  This requires allocating for and storing the CLIENTHELLO_MSG
in the SSL object to be preserved across such calls, but the storage is
reclaimed after ClientHello processing finishes.

Information about the CliehtHello is available to the callback by means of
accessor functions that can only be used from the early callback.  This allows
extensions to make use of the existing internal parsing machinery without
exposing structure internals (e.g., of PACKET), so that applications do not
have to write fragile parsing code.

Applications are encouraged to utilize an early callback and not use
a servername_callback, in order to avoid unexpected behavior that
occurs due to the relative order of processing between things like
session resumption and the historical servername callback.

Also tidy up nearby style by removing unnecessary braces around one-line
conditional bodies.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)

Prepare for WORK_MORE_C

Add the new enum value and case statements as appropriate.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Richard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2279)