Updated: 2021/Apr/14


BN_new(3)                           OpenSSL                          BN_new(3)



NAME
       BN_new, BN_secure_new, BN_clear, BN_free, BN_clear_free - allocate and
       free BIGNUMs

LIBRARY
       libcrypto, -lcrypto

SYNOPSIS
        #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);

DESCRIPTION
       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)

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

COPYRIGHT
       Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.



1.1.1i                            2020-01-23                         BN_new(3)