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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 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 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)

COPYRIGHT
       Copyright 2000-2016 The OpenSSL Project Authors.	All Rights Reserved.

       Licensed	under the OpenSSL license (the "License").  You	may not	use
       this file except	in compliance with the License.	 You can obtain	a copy
       in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

1.1.1a				  2018-11-20		       BN_CTX_START(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | SEE ALSO | COPYRIGHT

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