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man pages section 3: Extended Library Functions, Volume 1

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Updated: Wednesday, July 27, 2022
 
 

BN_CTX_new (3openssl)

Name

BN_CTX_new - allocate and free BN_CTX structures

Synopsis

#include <openssl/bn.h>

BN_CTX *BN_CTX_new(void);

void BN_CTX_free(BN_CTX *c);

Deprecated:

void BN_CTX_init(BN_CTX *c);

Description

BN_CTX_new(3openssl)                OpenSSL               BN_CTX_new(3openssl)



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

SYNOPSIS
        #include <openssl/bn.h>

        BN_CTX *BN_CTX_new(void);

        void BN_CTX_free(BN_CTX *c);

       Deprecated:

        void BN_CTX_init(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_free() frees the components of the BN_CTX, and if it was created
       by BN_CTX_new(), also the structure itself.  If BN_CTX_start(3) has
       been used on the BN_CTX, BN_CTX_end(3) must be called before the BN_CTX
       may be freed by BN_CTX_free().

       BN_CTX_init() (deprecated) initializes an existing uninitialized
       BN_CTX.  This should not be used for new programs. Use BN_CTX_new()
       instead.

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

       BN_CTX_init() and BN_CTX_free() have no return values.


ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+--------------------------+
       |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
       +---------------+--------------------------+
       |Availability   | library/security/openssl |
       +---------------+--------------------------+
       |Stability      | Pass-through uncommitted |
       +---------------+--------------------------+

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

HISTORY
       BN_CTX_new() and BN_CTX_free() are available in all versions on SSLeay
       and OpenSSL. BN_CTX_init() was added in SSLeay 0.9.1b.



NOTES
       Source code for open source software components in Oracle Solaris can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This software was built from source available at
       https://github.com/oracle/solaris-userland.  The original community
       source was downloaded from
       https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.

       Further information about this software can be found on the open source
       community website at https://www.openssl.org/.



1.0.2ze                           2022-05-03              BN_CTX_new(3openssl)