BN_new, BN_init, BN_clear, BN_free, BN_clear_free - allocate and free BIGNUMs
#include <openssl/bn.h>
BIGNUM *BN_new(void);
void BN_init(BIGNUM *);
void BN_clear(BIGNUM *a);
void BN_free(BIGNUM *a);
void BN_clear_free(BIGNUM *a);
BN_new() allocates and initializes a BIGNUM structure. BN_init()
initializes an existing uninitialized BIGNUM.
BN_clear() is used to destroy sensitive data such as keys when they
are no longer needed. It erases the memory used by a and sets it
to the value 0.
BN_free() frees the components of the BIGNUM, and if it was created
by BN_new(), also the structure itself. BN_clear_free() additionally
overwrites the data before the memory is returned to the system.
If a is NULL, nothing is done.
BN_new() returns a pointer to the BIGNUM initialised to the value 0.
If the allocation fails,
it returns NULL and sets an error code that can be obtained
by ERR_get_error.
BN_init(), BN_clear(), BN_free() and BN_clear_free() have no return
values.
BN_new(), BN_clear(), BN_free() and BN_clear_free() are available in
all versions on SSLeay and OpenSSL. BN_init() was added in SSLeay
0.9.1b.