From 7b849c119daa33f4a20974a3a6198ed88d88179e Mon Sep 17 00:00:00 2001
From: "Diego F. Aranha" <dfaranha@gmail.com>
Date: Tue, 23 Apr 2024 19:03:43 +0200
Subject: [PATCH] Support fields where -3 is QNR.

---
 src/ep/relic_ep_curve.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/src/ep/relic_ep_curve.c b/src/ep/relic_ep_curve.c
index 707a7cfdd..420f56f83 100644
--- a/src/ep/relic_ep_curve.c
+++ b/src/ep/relic_ep_curve.c
@@ -173,7 +173,7 @@ static void ep_curve_set_map(void) {
 
 		/* If curve is not supersingular, precompute and store sqrt(-3)
 		 * neeed for hashing using the SwiftEC algorithm and variants. */
-		if (!ep_curve_is_super()) {
+		if (!ep_curve_is_super() && (ep_curve_opt_a() == RLC_ZERO || ep_curve_opt_b() == RLC_ZERO)) {
 			fp_set_dig(c4, 3);
 			fp_neg(c4, c4);
 			if (!fp_srt(c4, c4)) {
@@ -574,4 +574,5 @@ int ep_curve_frdim(void) {
 			return 16;
 			break;
 	}
-}
\ No newline at end of file
+	return 0;
+}