Apart from public and internal header files, there is a third type called
local header files, which are located next to source files in the source
directory. Currently, they have different suffixes like

  '*_lcl.h', '*_local.h', or '*_int.h'

This commit changes the different suffixes to '*_local.h' uniformly.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9681)

Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/6085)

Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5851)

Based on the description in https://github.com/openssl/openssl/pull/5757,
this re-implements the "allow NULL to be passed" behavior of a number of
xxx_free routines.  I also fixed up some egregious formatting errors
that were nearby.
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5761)

This removes some code because we cannot trace the original contributor
to get their agreement for the licence change (original commit e03ddfae).

After this change there will be numerous failures in the test cases until
someone rewrites the missing code.

All *_free functions should accept a NULL parameter. After this change
the following *_free functions will fail if a NULL parameter is passed:

BIO_ACCEPT_free()
BIO_CONNECT_free()
BN_BLINDING_free()
BN_CTX_free()
BN_MONT_CTX_free()
BN_RECP_CTX_free()
BUF_MEM_free()
COMP_CTX_free()
ERR_STATE_free()
TXT_DB_free()
X509_STORE_free()
ssl3_free()
ssl_cert_free()
SSL_SESSION_free()
SSL_free()

[skip ci]
Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/5757)

Since return is inconsistent, I removed unnecessary parentheses and
unified them.
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4541)

unified them.
- return (0); -> return 0;
- return (1); -> return 1;
- return (-1); -> return -1;
Reviewed-by: NStephen Henson <steve@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4500)

To make it consistent in the code base
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NBernd Edlinger <bernd.edlinger@hotmail.de>
(Merged from https://github.com/openssl/openssl/pull/3749)

BN_RECP_CTX_new direclty use bn_init to avoid twice memset calls
Reviewed-by: NKurt Roeckx <kurt@openssl.org>
Reviewed-by: NRich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1879)

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

Remove some duplicated NULL/zero init.
Signed-off-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NTim Hudson <tjh@openssl.org>

This was done by the following
        find . -name '*.[ch]' | /tmp/pl
where /tmp/pl is the following three-line script:
        print unless $. == 1 && m@/\* .*\.[ch] \*/@;
        close ARGV if eof; # Close file to reset $.

And then some hand-editing of other files.
Reviewed-by: NViktor Dukhovni <viktor@openssl.org>

Rename it to be an internal function bn_init.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

There are header files in crypto/ that are used by a number of crypto/
submodules.  Move those to crypto/include/internal and adapt the
affected source code and Makefiles.

The header files that got moved are:

crypto/cryptolib.h
crypto/md32_common.h
Reviewed-by: NRich Salz <rsalz@openssl.org>

For a local variable:
        TYPE *p;
Allocations like this are "risky":
        p = OPENSSL_malloc(sizeof(TYPE));
if the type of p changes, and the malloc call isn't updated, you
could get memory corruption.  Instead do this:
        p = OPENSSL_malloc(sizeof(*p));
Also fixed a few memset() calls that I noticed while doing this.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Following ANSI C rules, remove the casts from calls to
OPENSSL_malloc and OPENSSL_realloc.
Reviewed-by: NRichard Levitte <levitte@openssl.org>

This is a final pass looking for '#if 0'/'#if 1' controls and
removing the appropriate pieces.
Reviewed-by: NAndy Polyakov <appro@openssl.org>

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

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

indent will not alter them when reformatting comments
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NMatt Caswell <matt@openssl.org>

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

Several files #include stdio.h and don't need it.
Also, per tjh, remove BN_COUNT
Reviewed-by: NEmilia Kasper <emilia@openssl.org>

crypto.h if needed.

Modify source tree to handle change.

OpenSSL malloc dependencies.

knock-on work than expected - they've been extracted into a patch
series that can be completed elsewhere, or in a different branch,
before merging back to HEAD.

        -Wmissing-prototypes -Wcomment -Wformat -Wimplicit -Wmain -Wmultichar
        -Wswitch -Wshadow -Wtrigraphs -Werror -Wchar-subscripts
        -Wstrict-prototypes -Wreturn-type -Wpointer-arith  -W -Wunused
        -Wno-unused-parameter -Wuninitialized

("perl util/ck_errf.pl */*.c */*/*.c" still reports many more.)

locally initialising their own.

NB: I've removed the "BN_clear_free()" loops for the exit-paths in some of
these functions, and that may be a major part of the performance
improvements we're seeing. The "free" part can be removed because we're
using BN_CTX. The "clear" part OTOH can be removed because BN_CTX
destruction automatically performs this task, so performing it inside
functions that may be called repeatedly is wasteful. This is currently safe
within openssl due to the fact that BN_CTX objects are never created for
longer than a single high-level operation. However, that is only because
there's currently no mechanism in openssl for thread-local storage. Beyond
that, this might be an issue for applications using the bignum API directly
and caching their own BN_CTX objects. The solution is to introduce a flag
to BN_CTX_start() that allows its variables to be automatically sanitised
on release during BN_CTX_end(). This way any higher-level function (and
perhaps the application) can specify this flag in its own
BN_CTX_start()/BN_CTX_end() pair, and this will cause inner-loop functions
specifying the flag to be ignored so that sanitisation is handled only once
back out at the higher level. I will be implementing this in the near
future.

Remove certain redundant BN_zero() initialisations, because BN_CTX_get(),
BN_init(), [etc] already initialise to zero.

Correct error checking in bn_sqr.c, and be less wishy-wash about how/why
the result's 'top' value is set (note also, 'max' is always > 0 at this
point).

bn_correct_top() or bn_check_top() depending on debug settings. For
internal source, all bn_fix_top()s should be converted one way or the other
depending on whether the use of bn_correct_top() is justified.

For BN_div_recp(), these cases should not require correction if the other
bignum functions are doing their jobs properly, so convert to
bn_check_top().

is itself experimental, and in addition may cause execution to break on
existing openssl "bugs" that previously were harmless or at least
invisible.

structures being passed in to or out of API functions, and this corrects a
couple of cases found so far.

Also, lop off a couple of bytes of white-space.

One problem that looked like a problem in bn_recp.c at first turned
out to be a BN_mul bug.  An example is given in bn_recp.c; finding
the bug responsible for this is left as an exercise.

"make update"

two functions that did expansion on in parameters (BN_mul() and
BN_sqr()).  The problem was solved by making bn_dup_expand() which is
a mix of bn_expand2() and BN_dup().

like Malloc, Realloc and especially Free conflict with already existing names
on some operating systems or other packages.  That is reason enough to change
the names of the OpenSSL memory allocation macros to something that has a
better chance of being unique, like prepending them with OPENSSL_.

This change includes all the name changes needed throughout all C files.