OpenSSL

Cryptography and SSL/TLS Toolkit

BN_zero

NAME

BN_zero, BN_one, BN_value_one, BN_set_word, BN_get_word - BIGNUM assignment operations

SYNOPSIS

 #include <openssl/bn.h>

 void BN_zero(BIGNUM *a);
 int BN_one(BIGNUM *a);

 const BIGNUM *BN_value_one(void);

 int BN_set_word(BIGNUM *a, unsigned long w);
 unsigned long BN_get_word(BIGNUM *a);

Deprecated:

 #if OPENSSL_API_COMPAT < 0x00908000L
 int BN_zero(BIGNUM *a);
 #endif

DESCRIPTION

BN_zero(), BN_one() and BN_set_word() set a to the values 0, 1 and w respectively. BN_zero() and BN_one() are macros.

BN_value_one() returns a BIGNUM constant of value 1. This constant is useful for use in comparisons and assignment.

BN_get_word() returns a, if it can be represented as an unsigned long.

RETURN VALUES

BN_get_word() returns the value a, and 0xffffffffL if a cannot be represented as an unsigned long.

BN_one(), BN_set_word() and the deprecated version of BN_zero() return 1 on success, 0 otherwise. BN_value_one() returns the constant. The preferred version of BN_zero() never fails and returns no value.

BUGS

Someone might change the constant.

If a BIGNUM is equal to 0xffffffffL it can be represented as an unsigned long but this value is also returned on error.

SEE ALSO

bn, BN_bn2bin

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.