5 BN_CTX_new, BN_CTX_secure_new, BN_CTX_free - allocate and free BN_CTX structures
9 #include <openssl/bn.h>
11 BN_CTX *BN_CTX_new(void);
13 BN_CTX *BN_CTX_secure_new(void);
15 void BN_CTX_free(BN_CTX *c);
19 A B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by
20 library functions. Since dynamic memory allocation to create B<BIGNUM>s
21 is rather expensive when used in conjunction with repeated subroutine
22 calls, the B<BN_CTX> structure is used.
24 BN_CTX_new() allocates and initializes a B<BN_CTX> structure.
25 BN_CTX_secure_new() allocates and initializes a B<BN_CTX> structure
26 but uses the secure heap (see L<CRYPTO_secure_malloc(3)>) to hold the
29 BN_CTX_free() frees the components of the B<BN_CTX>, and if it was
30 created by BN_CTX_new(), also the structure itself.
31 If L<BN_CTX_start(3)> has been used on the B<BN_CTX>,
32 L<BN_CTX_end(3)> must be called before the B<BN_CTX>
33 may be freed by BN_CTX_free().
34 If B<c> is NULL, nothing is done.
38 BN_CTX_new() and BN_CTX_secure_new() return a pointer to the B<BN_CTX>.
39 If the allocation fails,
40 they return B<NULL> and sets an error code that can be obtained by
43 BN_CTX_free() has no return values.
45 =head1 REMOVED FUNCTIONALITY
47 void BN_CTX_init(BN_CTX *c);
49 BN_CTX_init() is no longer available as of OpenSSL 1.1.0. Applications should
50 replace use of BN_CTX_init with BN_CTX_new instead:
61 L<ERR_get_error(3)>, L<BN_add(3)>,
66 BN_CTX_init() was removed in OpenSSL 1.1.0.
70 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
72 Licensed under the OpenSSL license (the "License"). You may not use
73 this file except in compliance with the License. You can obtain a copy
74 in the file LICENSE in the source distribution or at
75 L<https://www.openssl.org/source/license.html>.