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 25OPENSSL_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. 30 31BN_free() frees the components of the B<BIGNUM>, and if it was created 32by BN_new(), also the structure itself. BN_clear_free() additionally 33overwrites the data before the memory is returned to the system. 34If B<a> is NULL, nothing is done. 35 36=head1 RETURN VALUES 37 38BN_new() and BN_secure_new() 39return a pointer to the B<BIGNUM> initialised to the value 0. 40If the allocation fails, 41they return B<NULL> and set an error code that can be obtained 42by L<ERR_get_error(3)>. 43 44BN_clear(), BN_free() and BN_clear_free() have no return values. 45 46=head1 SEE ALSO 47 48L<ERR_get_error(3)> 49 50=head1 HISTORY 51 52BN_init() was removed in OpenSSL 1.1.0; use BN_new() instead. 53 54=head1 COPYRIGHT 55 56Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. 57 58Licensed under the OpenSSL license (the "License"). You may not use 59this file except in compliance with the License. You can obtain a copy 60in the file LICENSE in the source distribution or at 61L<https://www.openssl.org/source/license.html>. 62 63=cut 64