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dd8dec69 UM |
1 | =pod |
2 | ||
3 | =head1 NAME | |
4 | ||
c952780c | 5 | BN_CTX_new, BN_CTX_secure_new, BN_CTX_free - allocate and free BN_CTX structures |
dd8dec69 UM |
6 | |
7 | =head1 SYNOPSIS | |
8 | ||
9 | #include <openssl/bn.h> | |
10 | ||
11 | BN_CTX *BN_CTX_new(void); | |
12 | ||
74924dcb RS |
13 | BN_CTX *BN_CTX_secure_new(void); |
14 | ||
aafbe1cc MC |
15 | void BN_CTX_free(BN_CTX *c); |
16 | ||
dd8dec69 UM |
17 | =head1 DESCRIPTION |
18 | ||
15701211 DSH |
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. | |
dd8dec69 | 23 | |
74924dcb RS |
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 | |
27 | B<BIGNUM>s. | |
dd8dec69 UM |
28 | |
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. | |
9b86974e RS |
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> | |
37e48b88 | 33 | may be freed by BN_CTX_free(). |
23a1d5e9 | 34 | If B<c> is NULL, nothing is done. |
37e48b88 | 35 | |
dd8dec69 UM |
36 | =head1 RETURN VALUES |
37 | ||
74924dcb RS |
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 | |
9b86974e | 41 | L<ERR_get_error(3)>. |
dd8dec69 | 42 | |
e35af275 MC |
43 | BN_CTX_free() has no return values. |
44 | ||
45 | =head1 REMOVED FUNCTIONALITY | |
46 | ||
47 | void BN_CTX_init(BN_CTX *c); | |
48 | ||
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: | |
51 | ||
52 | BN_CTX *ctx; | |
53 | ctx = BN_CTX_new(); | |
54 | if(!ctx) /* Handle error */ | |
55 | ... | |
56 | BN_CTX_free(ctx); | |
dd8dec69 UM |
57 | |
58 | =head1 SEE ALSO | |
59 | ||
9e183d22 | 60 | L<ERR_get_error(3)>, L<BN_add(3)>, |
9b86974e | 61 | L<BN_CTX_start(3)> |
dd8dec69 UM |
62 | |
63 | =head1 HISTORY | |
64 | ||
a528d4f0 | 65 | BN_CTX_init() was removed in OpenSSL 1.1.0. |
dd8dec69 | 66 | |
e2f92610 RS |
67 | =head1 COPYRIGHT |
68 | ||
9e183d22 | 69 | Copyright 2000-2017 The OpenSSL Project Authors. All Rights Reserved. |
e2f92610 RS |
70 | |
71 | Licensed under the OpenSSL license (the "License"). You may not use | |
72 | this file except in compliance with the License. You can obtain a copy | |
73 | in the file LICENSE in the source distribution or at | |
74 | L<https://www.openssl.org/source/license.html>. | |
75 | ||
76 | =cut |