From 16a3f20c3b974ad263494466384b2f9461316b5b Mon Sep 17 00:00:00 2001
From: guipublic <guipublic@gmail.com>
Date: Fri, 4 Oct 2024 11:59:17 +0000
Subject: [PATCH] check for Schnorr null signature

---
 noir_stdlib/src/schnorr.nr | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/noir_stdlib/src/schnorr.nr b/noir_stdlib/src/schnorr.nr
index e24aabf3cda..0623f116dea 100644
--- a/noir_stdlib/src/schnorr.nr
+++ b/noir_stdlib/src/schnorr.nr
@@ -41,6 +41,8 @@ pub fn verify_signature_noir<let N: u32>(
         for i in 0..32 {
             is_ok &= result[i] == signature[32 + i];
         }
+    } else {
+        is_ok = false;
     }
     is_ok
 }
@@ -92,3 +94,12 @@ fn calculate_signature_challenge<let N: u32>(
     let result = crate::hash::blake2s(hash_input);
     (r.is_infinite, result)
 }
+
+#[test]
+fn test_zero_signature() {
+    let public_key: EmbeddedCurvePoint = EmbeddedCurvePoint { x: 1, y: 17631683881184975370165255887551781615748388533673675138860, is_infinite: false };
+    let signature: [u8; 64] = [0; 64];
+    let message: [u8; _] = [2; 64]; // every message
+    let verified = verify_signature_noir(public_key, signature, message);
+    assert(!verified);
+}