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.