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.

but the BN code had some problems that would cause failures when
doing certificate verification and some other functions.

Submitted by: Eric A Young from a C2Net version of SSLeay
Reviewed by: Mark J Cox
PR: