man BN_CTX_new - Man page for BN_CTX_new
June 1, 2007 – 1:20 amBN_CTX_new
Section: OpenSSL (3)
Updated: 2002–09–25
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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_init(BN_CTX *c);
void BN_CTX_free(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_init() initializes an existing uninitialized
BN_CTX.
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().
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.