yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | =pod |
| 2 | |
| 3 | =head1 NAME |
| 4 | |
| 5 | BN_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 | |
| 23 | BN_new() allocates and initializes a B<BIGNUM> structure. |
| 24 | BN_secure_new() does the same except that the secure heap |
| 25 | L<OPENSSL_secure_malloc(3)> is used to store the value. |
| 26 | |
| 27 | BN_clear() is used to destroy sensitive data such as keys when they |
| 28 | are no longer needed. It erases the memory used by B<a> and sets it |
| 29 | to the value 0. |
| 30 | If B<a> is NULL, nothing is done. |
| 31 | |
| 32 | BN_free() frees the components of the B<BIGNUM>, and if it was created |
| 33 | by BN_new(), also the structure itself. BN_clear_free() additionally |
| 34 | overwrites the data before the memory is returned to the system. |
| 35 | If B<a> is NULL, nothing is done. |
| 36 | |
| 37 | =head1 RETURN VALUES |
| 38 | |
| 39 | BN_new() and BN_secure_new() |
| 40 | return a pointer to the B<BIGNUM> initialised to the value 0. |
| 41 | If the allocation fails, |
| 42 | they return B<NULL> and set an error code that can be obtained |
| 43 | by L<ERR_get_error(3)>. |
| 44 | |
| 45 | BN_clear(), BN_free() and BN_clear_free() have no return values. |
| 46 | |
| 47 | =head1 SEE ALSO |
| 48 | |
| 49 | L<ERR_get_error(3)>, L<OPENSSL_secure_malloc(3)> |
| 50 | |
| 51 | =head1 HISTORY |
| 52 | |
| 53 | BN_init() was removed in OpenSSL 1.1.0; use BN_new() instead. |
| 54 | |
| 55 | =head1 COPYRIGHT |
| 56 | |
| 57 | Copyright 2000-2019 The OpenSSL Project Authors. All Rights Reserved. |
| 58 | |
| 59 | Licensed under the OpenSSL license (the "License"). You may not use |
| 60 | this file except in compliance with the License. You can obtain a copy |
| 61 | in the file LICENSE in the source distribution or at |
| 62 | L<https://www.openssl.org/source/license.html>. |
| 63 | |
| 64 | =cut |