from small one page howto to huge articles all in one place
 

search text in:





Poll
What does your sytem tell when running "ulimit -u"?








poll results

Last additions:
using iotop to find disk usage hogs

using iotop to find disk usage hogs

words:

887

views:

196097

userrating:

average rating: 1.7 (102 votes) (1=very good 6=terrible)


May 25th. 2007:
Words

486

Views

252151

why adblockers are bad


Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

Workaround and fixes for the current Core Dump Handling vulnerability affected kernels

words:

161

views:

141042

userrating:

average rating: 1.4 (42 votes) (1=very good 6=terrible)


April, 26th. 2006:

Druckversion
You are here: manpages





BN_add

Section: OpenSSL (3)
Updated: 2017-05-25
Index Return to Main Contents
 

NAME

BN_add, BN_sub, BN_mul, BN_sqr, BN_div, BN_mod, BN_nnmod, BN_mod_add, BN_mod_sub, BN_mod_mul, BN_mod_sqr, BN_exp, BN_mod_exp, BN_gcd - arithmetic operations on BIGNUMs  

SYNOPSIS

 #include <openssl/bn.h>

 int BN_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

 int BN_sub(BIGNUM *r, const BIGNUM *a, const BIGNUM *b);

 int BN_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx);

 int BN_sqr(BIGNUM *r, BIGNUM *a, BN_CTX *ctx);

 int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *a, const BIGNUM *d,
         BN_CTX *ctx);

 int BN_mod(BIGNUM *rem, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);

 int BN_nnmod(BIGNUM *r, const BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);

 int BN_mod_add(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
         BN_CTX *ctx);

 int BN_mod_sub(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
         BN_CTX *ctx);

 int BN_mod_mul(BIGNUM *r, BIGNUM *a, BIGNUM *b, const BIGNUM *m,
         BN_CTX *ctx);

 int BN_mod_sqr(BIGNUM *r, BIGNUM *a, const BIGNUM *m, BN_CTX *ctx);

 int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx);

 int BN_mod_exp(BIGNUM *r, BIGNUM *a, const BIGNUM *p,
         const BIGNUM *m, BN_CTX *ctx);

 int BN_gcd(BIGNUM *r, BIGNUM *a, BIGNUM *b, BN_CTX *ctx);

 

DESCRIPTION

BN_add() adds a and b and places the result in r ("r=a+b"). r may be the same BIGNUM as a or b.

BN_sub() subtracts b from a and places the result in r ("r=a-b").

BN_mul() multiplies a and b and places the result in r ("r=a*b"). r may be the same BIGNUM as a or b. For multiplication by powers of 2, use BN_lshift(3).

BN_sqr() takes the square of a and places the result in r ("r=a^2"). r and a may be the same BIGNUM. This function is faster than BN_mul(r,a,a).

BN_div() divides a by d and places the result in dv and the remainder in rem ("dv=a/d, rem=a%d"). Either of dv and rem may be NULL, in which case the respective value is not returned. The result is rounded towards zero; thus if a is negative, the remainder will be zero or negative. For division by powers of 2, use BN_rshift(3).

BN_mod() corresponds to BN_div() with dv set to NULL.

BN_nnmod() reduces a modulo m and places the non-negative remainder in r.

BN_mod_add() adds a to b modulo m and places the non-negative result in r.

BN_mod_sub() subtracts b from a modulo m and places the non-negative result in r.

BN_mod_mul() multiplies a by b and finds the non-negative remainder respective to modulus m ("r=(a*b) mod m"). r may be the same BIGNUM as a or b. For more efficient algorithms for repeated computations using the same modulus, see BN_mod_mul_montgomery(3) and BN_mod_mul_reciprocal(3).

BN_mod_sqr() takes the square of a modulo m and places the result in r.

BN_exp() raises a to the p-th power and places the result in r ("r=a^p"). This function is faster than repeated applications of BN_mul().

BN_mod_exp() computes a to the p-th power modulo m ("r=a^p % m"). This function uses less time and space than BN_exp().

BN_gcd() computes the greatest common divisor of a and b and places the result in r. r may be the same BIGNUM as a or b.

For all functions, ctx is a previously allocated BN_CTX used for temporary variables; see BN_CTX_new(3).

Unless noted otherwise, the result BIGNUM must be different from the arguments.  

RETURN VALUES

For all functions, 1 is returned for success, 0 on error. The return value should always be checked (e.g., "if (!BN_add(r,a,b)) goto err;"). The error codes can be obtained by ERR_get_error(3).  

SEE ALSO

bn(3), ERR_get_error(3), BN_CTX_new(3), BN_add_word(3), BN_set_bit(3)  

HISTORY

BN_add(), BN_sub(), BN_sqr(), BN_div(), BN_mod(), BN_mod_mul(), BN_mod_exp() and BN_gcd() are available in all versions of SSLeay and OpenSSL. The ctx argument to BN_mul() was added in SSLeay 0.9.1b. BN_exp() appeared in SSLeay 0.9.0. BN_nnmod(), BN_mod_add(), BN_mod_sub(), and BN_mod_sqr() were added in OpenSSL 0.9.7.


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
SEE ALSO
HISTORY





Support us on Content Nation
rdf newsfeed | rss newsfeed | Atom newsfeed
- Powered by LeopardCMS - Running on Gentoo -
Copyright 2004-2020 Sascha Nitsch Unternehmensberatung GmbH
Valid XHTML1.1 : Valid CSS : buttonmaker
- Level Triple-A Conformance to Web Content Accessibility Guidelines 1.0 -
- Copyright and legal notices -
Time to create this page: 19.3 ms