diff options
Diffstat (limited to 'openssl-1.1.0h/doc/crypto/BN_add.pod')
| -rw-r--r-- | openssl-1.1.0h/doc/crypto/BN_add.pod | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/openssl-1.1.0h/doc/crypto/BN_add.pod b/openssl-1.1.0h/doc/crypto/BN_add.pod new file mode 100644 index 0000000..db3b0d4 --- /dev/null +++ b/openssl-1.1.0h/doc/crypto/BN_add.pod @@ -0,0 +1,127 @@ +=pod + +=head1 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 + +=head1 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); + +=head1 DESCRIPTION + +BN_add() adds I<a> and I<b> and places the result in I<r> (C<r=a+b>). +I<r> may be the same B<BIGNUM> as I<a> or I<b>. + +BN_sub() subtracts I<b> from I<a> and places the result in I<r> (C<r=a-b>). +I<r> may be the same B<BIGNUM> as I<a> or I<b>. + +BN_mul() multiplies I<a> and I<b> and places the result in I<r> (C<r=a*b>). +I<r> may be the same B<BIGNUM> as I<a> or I<b>. +For multiplication by powers of 2, use L<BN_lshift(3)>. + +BN_sqr() takes the square of I<a> and places the result in I<r> +(C<r=a^2>). I<r> and I<a> may be the same B<BIGNUM>. +This function is faster than BN_mul(r,a,a). + +BN_div() divides I<a> by I<d> and places the result in I<dv> and the +remainder in I<rem> (C<dv=a/d, rem=a%d>). Either of I<dv> and I<rem> may +be B<NULL>, in which case the respective value is not returned. +The result is rounded towards zero; thus if I<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 I<dv> set to B<NULL>. + +BN_nnmod() reduces I<a> modulo I<m> and places the non-negative +remainder in I<r>. + +BN_mod_add() adds I<a> to I<b> modulo I<m> and places the non-negative +result in I<r>. + +BN_mod_sub() subtracts I<b> from I<a> modulo I<m> and places the +non-negative result in I<r>. + +BN_mod_mul() multiplies I<a> by I<b> and finds the non-negative +remainder respective to modulus I<m> (C<r=(a*b) mod m>). I<r> may be +the same B<BIGNUM> as I<a> or I<b>. For more efficient algorithms for +repeated computations using the same modulus, see +L<BN_mod_mul_montgomery(3)> and +L<BN_mod_mul_reciprocal(3)>. + +BN_mod_sqr() takes the square of I<a> modulo B<m> and places the +result in I<r>. + +BN_exp() raises I<a> to the I<p>-th power and places the result in I<r> +(C<r=a^p>). This function is faster than repeated applications of +BN_mul(). + +BN_mod_exp() computes I<a> to the I<p>-th power modulo I<m> (C<r=a^p % +m>). This function uses less time and space than BN_exp(). + +BN_gcd() computes the greatest common divisor of I<a> and I<b> and +places the result in I<r>. I<r> may be the same B<BIGNUM> as I<a> or +I<b>. + +For all functions, I<ctx> is a previously allocated B<BN_CTX> used for +temporary variables; see L<BN_CTX_new(3)>. + +Unless noted otherwise, the result B<BIGNUM> must be different from +the arguments. + +=head1 RETURN VALUES + +For all functions, 1 is returned for success, 0 on error. The return +value should always be checked (e.g., C<if (!BN_add(r,a,b)) goto err;>). +The error codes can be obtained by L<ERR_get_error(3)>. + +=head1 SEE ALSO + +L<ERR_get_error(3)>, L<BN_CTX_new(3)>, +L<BN_add_word(3)>, L<BN_set_bit(3)> + +=head1 COPYRIGHT + +Copyright 2000-2017 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 +L<https://www.openssl.org/source/license.html>. + +=cut |