NAME

BN_new, BN_init, BN_clear, BN_free, BN_clear_free − Allocate and free BIGNUMs

SYNOPSIS

#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 );

DESCRIPTION

The BN_new() function allocates and initializes a BIGNUM structure. The BN_init() function initializes an existing uninitialized BIGNUM. 

The BN_clear() function 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. 

The BN_free() function frees the components of the BIGNUM, and if it was created by BN_new(), also the structure itself. The BN_clear_free() function overwrites the data before the memory is returned to the system. 

RETURN VALUES

The BN_new() function returns a pointer to the BIGNUM. If the allocation fails, it returns NULL and sets an error code that can be obtained by using ERR_get_error(). 

The BN_init(), BN_clear(), BN_free(), and BN_clear_free() functions have no return values. 

HISTORY

The BN_new(), BN_clear(), BN_free(), and BN_clear_free() functions are available in all versions on SSLeay and OpenSSL.  The BN_init() function was added in SSLeay 0.9.1b. 

SEE ALSO

Functions: bn(3), err(3)