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BN_CTX_NEW(3)			    OpenSSL			 BN_CTX_NEW(3)

NAME
       BN_CTX_new, BN_CTX_secure_new, BN_CTX_free - allocate and free BN_CTX
       structures

SYNOPSIS
	#include <openssl/bn.h>

	BN_CTX *BN_CTX_new(void);

	BN_CTX *BN_CTX_secure_new(void);

	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 BIGNUMs 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_secure_new() allocates and initializes a BN_CTX structure	but
       uses the	secure heap (see CRYPTO_secure_malloc(3)) to hold the BIGNUMs.

       BN_CTX_free() frees the components of the BN_CTX	and the	structure
       itself.	Since BN_CTX_start() is	required in order to obtain BIGNUMs
       from the	BN_CTX,	in most	cases BN_CTX_end() must	be called before the
       BN_CTX may be freed by BN_CTX_free().  If c is NULL, nothing is done.

       A given BN_CTX must only	be used	by a single thread of execution.  No
       locking is performed, and the internal pool allocator will not properly
       handle multiple threads of execution.

RETURN VALUES
       BN_CTX_new() and	BN_CTX_secure_new() return a pointer to	the BN_CTX.
       If the allocation fails,	they return NULL and sets an error code	that
       can be obtained by ERR_get_error(3).

       BN_CTX_free() has no return values.

REMOVED	FUNCTIONALITY
	void BN_CTX_init(BN_CTX	*c);

       BN_CTX_init() is	no longer available as of OpenSSL 1.1.0. Applications
       should replace use of BN_CTX_init with BN_CTX_new instead:

	BN_CTX *ctx;
	ctx = BN_CTX_new();
	if (!ctx)
	    /* error */
	...
	BN_CTX_free(ctx);

SEE ALSO
       ERR_get_error(3), BN_add(3), BN_CTX_start(3)

HISTORY
       BN_CTX_init() was removed in OpenSSL 1.1.0.

COPYRIGHT
       Copyright 2000-2017 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>.

1.1.1d				  2019-09-10			 BN_CTX_NEW(3)

NAME | SYNOPSIS | DESCRIPTION | RETURN VALUES | REMOVED FUNCTIONALITY | SEE ALSO | HISTORY | COPYRIGHT

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