| =pod |
| |
| =head1 NAME |
| |
| BN_mod_inverse - compute inverse modulo n |
| |
| =head1 SYNOPSIS |
| |
| #include <openssl/bn.h> |
| |
| BIGNUM *BN_mod_inverse(BIGNUM *r, BIGNUM *a, const BIGNUM *n, |
| BN_CTX *ctx); |
| |
| =head1 DESCRIPTION |
| |
| BN_mod_inverse() computes the inverse of B<a> modulo B<n> |
| places the result in B<r> (C<(a*r)%n==1>). If B<r> is NULL, |
| a new B<BIGNUM> is created. |
| |
| B<ctx> is a previously allocated B<BN_CTX> used for temporary |
| variables. B<r> may be the same B<BIGNUM> as B<a> or B<n>. |
| |
| =head1 RETURN VALUES |
| |
| BN_mod_inverse() returns the B<BIGNUM> containing the inverse, and |
| NULL on error. The error codes can be obtained by L<ERR_get_error(3)|ERR_get_error(3)>. |
| |
| =head1 SEE ALSO |
| |
| L<bn(3)|bn(3)>, L<ERR_get_error(3)|ERR_get_error(3)>, L<BN_add(3)|BN_add(3)> |
| |
| =head1 HISTORY |
| |
| BN_mod_inverse() is available in all versions of SSLeay and OpenSSL. |
| |
| =cut |
