BN_mod_sqrt
BIGNUM *BN_mod_sqrt(BIGNUM *ret,
LCRYPTO_ALIAS(BN_mod_sqrt);
if (!BN_mod_sqrt(y, y, p, ctx)) {
LCRYPTO_USED(BN_mod_sqrt);
if (BN_mod_sqrt(got, a, p, ctx) == NULL) {
if (BN_mod_sqrt(got, a, p, ctx) == NULL) {
if (!BN_mod_sqrt(r, a, p, ctx))