1.\" $OpenBSD: BN_CTX_new.3,v 1.9 2019/06/10 14:58:48 schwarze Exp $ 2.\" OpenSSL aafbe1cc Jun 12 23:42:08 2013 +0100 3.\" 4.\" This file was written by Ulf Moeller <ulf@openssl.org>. 5.\" Copyright (c) 2000, 2013 The OpenSSL Project. All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions 9.\" are met: 10.\" 11.\" 1. Redistributions of source code must retain the above copyright 12.\" notice, this list of conditions and the following disclaimer. 13.\" 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in 16.\" the documentation and/or other materials provided with the 17.\" distribution. 18.\" 19.\" 3. All advertising materials mentioning features or use of this 20.\" software must display the following acknowledgment: 21.\" "This product includes software developed by the OpenSSL Project 22.\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" 23.\" 24.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to 25.\" endorse or promote products derived from this software without 26.\" prior written permission. For written permission, please contact 27.\" openssl-core@openssl.org. 28.\" 29.\" 5. Products derived from this software may not be called "OpenSSL" 30.\" nor may "OpenSSL" appear in their names without prior written 31.\" permission of the OpenSSL Project. 32.\" 33.\" 6. Redistributions of any form whatsoever must retain the following 34.\" acknowledgment: 35.\" "This product includes software developed by the OpenSSL Project 36.\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" 37.\" 38.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY 39.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 40.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 41.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR 42.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 43.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 44.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 45.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 46.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 47.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 48.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED 49.\" OF THE POSSIBILITY OF SUCH DAMAGE. 50.\" 51.Dd $Mdocdate: June 10 2019 $ 52.Dt BN_CTX_NEW 3 53.Os 54.Sh NAME 55.Nm BN_CTX_new , 56.Nm BN_CTX_free , 57.Nm BN_CTX_init 58.Nd allocate and free BN_CTX structures 59.Sh SYNOPSIS 60.In openssl/bn.h 61.Ft BN_CTX * 62.Fo BN_CTX_new 63.Fa void 64.Fc 65.Ft void 66.Fo BN_CTX_free 67.Fa "BN_CTX *c" 68.Fc 69.Pp 70Deprecated: 71.Pp 72.Ft void 73.Fo BN_CTX_init 74.Fa "BN_CTX *c" 75.Fc 76.Sh DESCRIPTION 77A 78.Vt BN_CTX 79is a structure that holds 80.Vt BIGNUM 81temporary variables used by library functions. 82Since dynamic memory allocation to create 83.Vt BIGNUM Ns s 84is rather expensive when used in conjunction with repeated subroutine 85calls, the 86.Vt BN_CTX 87structure is used. 88.Pp 89.Fn BN_CTX_new 90allocates and initializes a 91.Vt BN_CTX 92structure. 93.Pp 94.Fn BN_CTX_free 95frees the components of the 96.Vt BN_CTX 97and, if it was created by 98.Fn BN_CTX_new , 99also the structure itself. 100If 101.Xr BN_CTX_start 3 102has been used on the 103.Vt BN_CTX , 104.Xr BN_CTX_end 3 105must be called before the 106.Vt BN_CTX 107may be freed by 108.Fn BN_CTX_free . 109If 110.Fa c 111is a 112.Dv NULL 113pointer, no action occurs. 114.Pp 115.Fn BN_CTX_init 116(deprecated) initializes an existing uninitialized 117.Vt BN_CTX . 118This should not be used for new programs. 119Use 120.Fn BN_CTX_new 121instead. 122.Sh RETURN VALUES 123.Fn BN_CTX_new 124returns a pointer to the 125.Vt BN_CTX . 126If the allocation fails, it returns 127.Dv NULL 128and sets an error code that can be obtained by 129.Xr ERR_get_error 3 . 130.Sh SEE ALSO 131.Xr BN_add 3 , 132.Xr BN_CTX_start 3 , 133.Xr BN_new 3 134.Sh HISTORY 135.Fn BN_CTX_new 136and 137.Fn BN_CTX_free 138first appeared in SSLeay 0.5.1 and have been available since 139.Ox 2.4 . 140.Pp 141.Fn BN_CTX_init 142first appeared in SSLeay 0.9.1 and has been available since 143.Ox 2.6 . 144