manpagez: man pages & more
man BN_CTX_get(3)
Home | html | info | man
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.  If ctx is NULL, nothing is done.  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 2000-2019 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>.



1.1.1c                            2019-05-28                   BN_CTX_start(3)

openssl 1.1.1c - Generated Mon Jun 10 13:01:48 CDT 2019
© manpagez.com 2000-2024
Individual documents may contain additional copyright information.