BN_mod_inverse(3)

BN_mod_inverse(3)            OpenSSL            BN_mod_inverse(3)

NAME

     BN_mod_inverse - compute inverse modulo n

SYNOPSIS

      #include <openssl/bn.h>

      BIGNUM *BN_mod_inverse(BIGNUM *r, BIGNUM *a, const BIGNUM *n,
                BN_CTX *ctx);

DESCRIPTION

     BN_mod_inverse() computes the inverse of a modulo n places
     the result in r ("(a*r)%n==1"). If r is NULL, a new BIGNUM
     is created.

     ctx is a previously allocated BN_CTX used for temporary
     variables. r may be the same BIGNUM as a or n.

RETURN VALUES

     BN_mod_inverse() returns the BIGNUM containing the inverse,
     and NULL on error. The error codes can be obtained by
     ERR_get_error(3).

SEE ALSO

     bn(3), ERR_get_error(3), BN_add(3)

HISTORY

     BN_mod_inverse() is available in all versions of SSLeay and
     OpenSSL.

1.0.2t               Last change: 2019-09-10                    1