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 void BN_CTX_init(BN_CTX *c);
22 A B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by
23 library functions. Since dynamic memory allocation to create B<BIGNUM>s
24 is rather expensive when used in conjunction with repeated subroutine
25 calls, the B<BN_CTX> structure is used.
27 BN_CTX_new() allocates and initializes a B<BN_CTX>
30 BN_CTX_free() frees the components of the B<BN_CTX>, and if it was
31 created by BN_CTX_new(), also the structure itself.
32 If L<BN_CTX_start(3)|BN_CTX_start(3)> has been used on the B<BN_CTX>,
33 L<BN_CTX_end(3)|BN_CTX_end(3)> must be called before the B<BN_CTX>
34 may be freed by BN_CTX_free().
36 BN_CTX_init() (deprecated) initializes an existing uninitialized B<BN_CTX>.
37 This should not be used for new programs. Use BN_CTX_new() instead.
41 BN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails,
42 it returns B<NULL> and sets an error code that can be obtained by
43 L<ERR_get_error(3)|ERR_get_error(3)>.
45 BN_CTX_init() and BN_CTX_free() have no return values.
49 L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>,
50 L<BN_CTX_start(3)|BN_CTX_start(3)>
54 BN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay
55 and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.