NAME¶
BN_CTX_new, BN_CTX_init, BN_CTX_free - allocate and free BN_CTX structures
SYNOPSIS¶
#include <openssl/bn.h>
BN_CTX *BN_CTX_new(void);
void BN_CTX_free(BN_CTX *c);
Deprecated:
void BN_CTX_init(BN_CTX *c);
DESCRIPTION¶
A
BN_CTX is a structure that holds
BIGNUM temporary variables used
by library functions. Since dynamic memory allocation to create
BIGNUMs
is rather expensive when used in conjunction with repeated subroutine calls,
the
BN_CTX structure is used.
BN_CTX_new() allocates and initializes a
BN_CTX structure.
BN_CTX_free() frees the components of the
BN_CTX, and if it was
created by
BN_CTX_new(), also the structure itself. If
BN_CTX_start(3) has been used on the
BN_CTX,
BN_CTX_end(3) must be called before the
BN_CTX may be freed by
BN_CTX_free().
BN_CTX_init() (deprecated) initializes an existing uninitialized
BN_CTX. This should not be used for new programs. Use
BN_CTX_new() instead.
RETURN VALUES¶
BN_CTX_new() returns a pointer to the
BN_CTX. If the allocation
fails, it returns
NULL and sets an error code that can be obtained by
ERR_get_error(3).
BN_CTX_init() and
BN_CTX_free() have no return values.
SEE ALSO¶
bn(3),
ERR_get_error(3),
BN_add(3),
BN_CTX_start(3)
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.