5 BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
9 #include <openssl/bn.h>
11 BN_CTX *BN_CTX_new(void);
13 void BN_CTX_free(BN_CTX *c);
17 A B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by
18 library functions. Since dynamic memory allocation to create B<BIGNUM>s
19 is rather expensive when used in conjunction with repeated subroutine
20 calls, the B<BN_CTX> structure is used.
22 BN_CTX_new() allocates and initializes a B<BN_CTX>
25 BN_CTX_free() frees the components of the B<BN_CTX>, and if it was
26 created by BN_CTX_new(), also the structure itself.
27 If L<BN_CTX_start(3)|BN_CTX_start(3)> has been used on the B<BN_CTX>,
28 L<BN_CTX_end(3)|BN_CTX_end(3)> must be called before the B<BN_CTX>
29 may be freed by BN_CTX_free().
33 BN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails,
34 it returns B<NULL> and sets an error code that can be obtained by
35 L<ERR_get_error(3)|ERR_get_error(3)>.
37 BN_CTX_free() has no return values.
39 =head1 REMOVED FUNCTIONALITY
41 void BN_CTX_init(BN_CTX *c);
43 BN_CTX_init() is no longer available as of OpenSSL 1.1.0. Applications should
44 replace use of BN_CTX_init with BN_CTX_new instead:
48 if(!ctx) /* Handle error */
54 L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>,
55 L<BN_CTX_start(3)|BN_CTX_start(3)>
59 BN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay
60 and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b and removed in OpenSSL