Section: OpenSSL (3SSL)
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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
(which can been created by using BN_CTX_new
in order to save the overhead of repeatedly creating and
s in functions that are called from inside a loop.
A function must call BN_CTX_start() first. Then, BN_CTX_get() may be
called repeatedly to obtain temporary BIGNUMs. All BN_CTX_get()
calls must be made before calling any other functions that use the
ctx as an argument.
Finally, BN_CTX_end() must be called before returning from the function.
When BN_CTX_end() is called, the BIGNUM pointers obtained from
BN_CTX_get() become invalid.
return no values.
BN_CTX_get() returns a pointer to the BIGNUM, or NULL on error.
Once BN_CTX_get() has failed, the subsequent calls will return NULL
as well, so it is sufficient to check the return value of the last
BN_CTX_get() call. In case of an error, an error code is set, which
can be obtained by ERR_get_error(3).
were added in OpenSSL 0.9.5.
- RETURN VALUES
- SEE ALSO