BN_div
int BN_div(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m, const BIGNUM *d,
#define BN_mod(rem,m,d,ctx) BN_div(NULL,(rem),(m),(d),(ctx))
BN_div(num, NULL, val, x, ctx);
BN_div(tmp, sk, sk, modulus, ctx);
bn_check(BN_div(r->number, NULL, b->number, a->number, ctx));
bn_check(BN_div(rdiv->number, rmod->number,
bn_check(BN_div(r->number, NULL, one,
bn_check(BN_div(x, NULL, n->number, x, ctx));
bn_check(BN_div(n, NULL, n, a, ctx));
bn_check(BN_div(i, f, n->number, a, ctx));
BN_div(tmp, sk, sk, modulus, ctx);