BN_CTX_start, BN_CTX_get, BN_CTX_end - use temporary BIGNUM variables
void BN_CTX_start(BN_CTX *ctx);
BIGNUM *BN_CTX_get(BN_CTX *ctx);
void BN_CTX_end(BN_CTX *ctx);
These functions are used to obtain temporary BIGNUM
variables from a
(which can been created by using BN_CTX_new(3)
) in order
to save the overhead of repeatedly creating and freeing BIGNUM
functions that are called from inside a loop.
A function must call BN_CTX_start()
first. Then, BN_CTX_get()
be called repeatedly to obtain temporary BIGNUM
calls must be made before calling any other functions that
use the ctx
as an argument.
must be called before returning from the function.
is called, the BIGNUM
pointers obtained from
return no values.
returns a pointer to the BIGNUM
, or NULL
error. Once BN_CTX_get()
has failed, the subsequent calls will return
as well, so it is sufficient to check the return value of the last
call. In case of an error, an error code is set, which can
be obtained by ERR_get_error(3)
were added in