5 BN_mod_inverse - Compute inverse modulo n
9 #include <openssl/bn.h>
11 BIGNUM *BN_mod_inverse(BIGNUM *r, BIGNUM *a, const BIGNUM *n, BN_CTX *ctx);
15 BN_mod_inverse() computes the inverse of B<a> modulo B<n>
16 places the result in B<r> (C<(a*r)%n==1>). If B<r> is NULL,
17 a new B<BIGNUM> is created.
19 B<ctx> is a previously allocated B<BN_CTX> used for temporary
20 variables. B<r> may be the same B<BIGNUM> as B<a> or B<n>.
24 BN_mod_inverse() returns the B<BIGNUM> containing the inverse, and
25 NULL on error. The error codes can be obtained by ERR_get_error(3).
29 bn(3), err(3), BN_add(3)
33 BN_mod_inverse() is available in all versions of SSLeay and OpenSSL.