| =pod |
| |
| =head1 NAME |
| |
| BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/bn.h> |
| |
| BN_CTX *BN_CTX_new(void); |
| |
| void BN_CTX_free(BN_CTX *c); |
| |
| =head1 DESCRIPTION |
| |
| A B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by |
| library functions. Since dynamic memory allocation to create B<BIGNUM>s |
| is rather expensive when used in conjunction with repeated subroutine |
| calls, the B<BN_CTX> structure is used. |
| |
| BN_CTX_new() allocates and initializes a B<BN_CTX> |
| structure. |
| |
| BN_CTX_free() frees the components of the B<BN_CTX>, and if it was |
| created by BN_CTX_new(), also the structure itself. |
| If L<BN_CTX_start(3)|BN_CTX_start(3)> has been used on the B<BN_CTX>, |
| L<BN_CTX_end(3)|BN_CTX_end(3)> must be called before the B<BN_CTX> |
| may be freed by BN_CTX_free(). |
| |
| =head1 RETURN VALUES |
| |
| BN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails, |
| it returns B<NULL> and sets an error code that can be obtained by |
| L<ERR_get_error(3)|ERR_get_error(3)>. |
| |
| BN_CTX_free() has no return values. |
| |
| =head1 REMOVED FUNCTIONALITY |
| |
| void BN_CTX_init(BN_CTX *c); |
| |
| BN_CTX_init() is no longer available as of OpenSSL 1.1.0. Applications should |
| replace use of BN_CTX_init with BN_CTX_new instead: |
| |
| BN_CTX *ctx; |
| ctx = BN_CTX_new(); |
| if(!ctx) /* Handle error */ |
| ... |
| BN_CTX_free(ctx); |
| |
| =head1 SEE ALSO |
| |
| L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>, |
| L<BN_CTX_start(3)|BN_CTX_start(3)> |
| |
| =head1 HISTORY |
| |
| BN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay |
| and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b and removed in OpenSSL |
| 1.1.0. |
| |
| =cut |
