159191Skris=pod
259191Skris
359191Skris=head1 NAME
459191Skris
559191SkrisBN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
659191Skris
759191Skris=head1 SYNOPSIS
859191Skris
959191Skris #include <openssl/bn.h>
1059191Skris
1159191Skris BN_CTX *BN_CTX_new(void);
1259191Skris
1359191Skris void BN_CTX_init(BN_CTX *c);
1459191Skris
1559191Skris void BN_CTX_free(BN_CTX *c);
1659191Skris
1759191Skris=head1 DESCRIPTION
1859191Skris
1959191SkrisA B<BN_CTX> is a structure that holds B<BIGNUM> temporary variables used by
2059191Skrislibrary functions. Since dynamic memory allocation to create B<BIGNUM>s
2159191Skrisis rather expensive when used in conjunction with repeated subroutine
2259191Skriscalls, the B<BN_CTX> structure is used.
2359191Skris
2459191SkrisBN_CTX_new() allocates and initializes a B<BN_CTX>
2559191Skrisstructure. BN_CTX_init() initializes an existing uninitialized
2659191SkrisB<BN_CTX>.
2759191Skris
2859191SkrisBN_CTX_free() frees the components of the B<BN_CTX>, and if it was
2959191Skriscreated by BN_CTX_new(), also the structure itself.
3059191SkrisIf L<BN_CTX_start(3)|BN_CTX_start(3)> has been used on the B<BN_CTX>,
3159191SkrisL<BN_CTX_end(3)|BN_CTX_end(3)> must be called before the B<BN_CTX>
3259191Skrismay be freed by BN_CTX_free().
3359191Skris
3459191Skris
3559191Skris=head1 RETURN VALUES
3659191Skris
3759191SkrisBN_CTX_new() returns a pointer to the B<BN_CTX>. If the allocation fails,
3859191Skrisit returns B<NULL> and sets an error code that can be obtained by
3959191SkrisL<ERR_get_error(3)|ERR_get_error(3)>.
4059191Skris
4159191SkrisBN_CTX_init() and BN_CTX_free() have no return values.
4259191Skris
4359191Skris=head1 SEE ALSO
4459191Skris
45109998SmarkmL<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)>,
4659191SkrisL<BN_CTX_start(3)|BN_CTX_start(3)>
4759191Skris
4859191Skris=head1 HISTORY
4959191Skris
5059191SkrisBN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay
5159191Skrisand OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.
5259191Skris
5359191Skris=cut
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