BN_CTX_end

BN_CTX_start(3)			   OpenSSL		      BN_CTX_start(3)



NAME
       BN_CTX_start, BN_CTX_get, BN_CTX_end - use temporary BIGNUM variables

SYNOPSIS
	#include <openssl/bn.h>

	void BN_CTX_start(BN_CTX *ctx);

	BIGNUM *BN_CTX_get(BN_CTX *ctx);

	void BN_CTX_end(BN_CTX *ctx);

DESCRIPTION
       These functions are used to obtain temporary BIGNUM variables from a
       BN_CTX (which can been created by using BN_CTX_new(3)) in order to
       save the overhead of repeatedly creating and freeing BIGNUMs in func-
       tions 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 func-
       tion.  When BN_CTX_end() is called, the BIGNUM pointers obtained from
       BN_CTX_get() become invalid.

RETURN VALUES
       BN_CTX_start() and BN_CTX_end() 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).

SEE ALSO
       BN_CTX_new(3)

HISTORY
       BN_CTX_start(), BN_CTX_get() and BN_CTX_end() were added in OpenSSL
       0.9.5.



0.9.7a				  2000-07-11		      BN_CTX_start(3)