1=pod 2 3=head1 NAME 4 5BN_new, BN_secure_new, BN_clear, BN_free, BN_clear_free - allocate and free BIGNUMs 6 7=head1 SYNOPSIS 8 9 #include <openssl/bn.h> 10 11 BIGNUM *BN_new(void); 12 13 BIGNUM *BN_secure_new(void); 14 15 void BN_clear(BIGNUM *a); 16 17 void BN_free(BIGNUM *a); 18 19 void BN_clear_free(BIGNUM *a); 20 21=head1 DESCRIPTION 22 23BN_new() allocates and initializes a B<BIGNUM> structure. 24BN_secure_new() does the same except that the secure heap 25L<OPENSSL_secure_malloc(3)> is used to store the value. 26 27BN_clear() is used to destroy sensitive data such as keys when they 28are no longer needed. It erases the memory used by B<a> and sets it 29to the value 0. 30If B<a> is NULL, nothing is done. 31 32BN_free() frees the components of the B<BIGNUM>, and if it was created 33by BN_new(), also the structure itself. BN_clear_free() additionally 34overwrites the data before the memory is returned to the system. 35If B<a> is NULL, nothing is done. 36 37=head1 RETURN VALUES 38 39BN_new() and BN_secure_new() 40return a pointer to the B<BIGNUM> initialised to the value 0. 41If the allocation fails, 42they return B<NULL> and set an error code that can be obtained 43by L<ERR_get_error(3)>. 44 45BN_clear(), BN_free() and BN_clear_free() have no return values. 46 47=head1 SEE ALSO 48 49L<ERR_get_error(3)>, L<OPENSSL_secure_malloc(3)> 50 51=head1 HISTORY 52 53BN_init() was removed in OpenSSL 1.1.0; use BN_new() instead. 54 55=head1 COPYRIGHT 56 57Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved. 58 59Licensed under the OpenSSL license (the "License"). You may not use 60this file except in compliance with the License. You can obtain a copy 61in the file LICENSE in the source distribution or at 62L<https://www.openssl.org/source/license.html>. 63 64=cut 65