bn_ctx_new(3) - Linux man page
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 BIGNUM s 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.