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

Submitted by: Martin Olsson <molsson@opera.com>

Check for bn_wexpand errors in bn_mul.c

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.

BN_mul failures at certain key-length mixes.
PR: 1427

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).

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

PR: 621

replaced #if logic around bn_sub_part_words in bn_mul.c. I rely upon
OPENSSL_BN_ASM_PART_WORDS being added by ./Configure script. Would it
still work on non-Unix platforms?

PR: 75

PR: 49

Fallback to normal multiply if n2 == 8 and dna or dnb is not zero
in bn_mul_recursive.

This is (hopefully) what was triggering bignum errors on 64 bit
platforms and causing the BN_mod_mul test to fail.

Submitted by: Toomas Kiisk <vix@cyber.ee>

sure they are available in opensslconf.h, by giving them names starting
with "OPENSSL_" to avoid conflicts with other packages and by making
sure e_os2.h will cover all platform-specific cases together with
opensslconf.h.

I've checked fairly well that nothing breaks with this (apart from
external software that will adapt if they have used something like
NO_KRB5), but I can't guarantee it completely, so a review of this
change would be a good thing.

in NO_ASM configurations

Solution: multiply a with 0, putting the result in r, and return.

when both a and b are of the exact right size.  This may change to
something better later.

Rewrite the extension code to use an ASN1_ITEM structure
for its ASN1 operations as well as the old style function
pointers (i2d, d2i, new, free). Change standard extensions
to support this.

Fix a warning in BN_mul(), bn_mul.c about uninitialised 'j'.

reliable timings yet, please try it out!

course, that means we need to handle the cases where the two arrays to
bn_mul_recursive() and bn_mul_part_recursive() differ in size.

I haven't yet changed the comments that describe bn_mul_recursive()
and bn_mul_part_recursive().  I want this to be tested by more people
before I consider this change final.  Please test away!

bn_add_words(), not bn_sub_words()...

BN_mul() correctly constified, avoids two realloc()'s that aren't
really necessary and saves memory to boot.  This required a small
change in bn_mul_part_recursive() and the addition of variants of
bn_cmp_words(), bn_add_words() and bn_sub_words() that can take arrays
with differing sizes.

The test results show a performance that very closely matches the
original code from before my constification.  This may seem like a
very small win from a performance point of view, but if one remembers
that the variants of bn_cmp_words(), bn_add_words() and bn_sub_words()
are not at all optimized for the moment (and there's no corresponding
assembler code), and that their use may be just as non-optimal, I'm
pretty confident there are possibilities...

This code needs reviewing!

stdout.  bc gets so confused by bean counts.

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().

that of the result pointer to bn_mul was the same as one of the two arguments,
That argument might have it's sign destroyed.  He provided this fix.

temporary BIGNUMs. BN_CTX still uses a fixed number of BIGNUMs, but
the BN_CTX implementation could now easily be changed.