BN_new.3ssl - Man Page

allocate and free BIGNUMs


 #include <openssl/bn.h>

 BIGNUM *BN_new(void);

 BIGNUM *BN_secure_new(void);

 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_secure_new() does the same except that the secure heap OPENSSL_secure_malloc(3) is used to store the value.

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. If a is NULL, nothing is done.

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.

Return Values

BN_new() and BN_secure_new() return a pointer to the BIGNUM initialised to the value 0. If the allocation fails, they return NULL and set an error code that can be obtained by ERR_get_error(3).

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

See Also

ERR_get_error(3), OPENSSL_secure_malloc(3)


BN_init() was removed in OpenSSL 1.1.0; use BN_new() instead.

Referenced By


The man pages BN_clear.3ssl(3), BN_clear_free.3ssl(3), BN_free.3ssl(3) and BN_secure_new.3ssl(3) are aliases of BN_new.3ssl(3).

2023-02-06 1.1.1q OpenSSL