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 the structure itself.
30 Since BN_CTX_start() is required in order to obtain B<BIGNUM>s from the
31 B<BN_CTX>, in most cases BN_CTX_end() must be called before the B<BN_CTX> may
32 be freed by BN_CTX_free(). If B<c> is NULL, nothing is done.
34 A given B<BN_CTX> must only be used by a single thread of execution. No
35 locking is performed, and the internal pool allocator will not properly handle
36 multiple threads of execution.
40 BN_CTX_new() and BN_CTX_secure_new() return a pointer to the B<BN_CTX>.
41 If the allocation fails,
42 they return B<NULL> and sets an error code that can be obtained by
45 BN_CTX_free() has no return values.
47 =head1 REMOVED FUNCTIONALITY
49 void BN_CTX_init(BN_CTX *c);
51 BN_CTX_init() is no longer available as of OpenSSL 1.1.0. Applications should
52 replace use of BN_CTX_init with BN_CTX_new instead:
63 L<ERR_get_error(3)>, L<BN_add(3)>,
68 BN_CTX_init() was removed in OpenSSL 1.1.0.
72 Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved.
74 Licensed under the OpenSSL license (the "License"). You may not use
75 this file except in compliance with the License. You can obtain a copy
76 in the file LICENSE in the source distribution or at
77 L<https://www.openssl.org/source/license.html>.