Add more tests for Scalar canonical checks

Author: elichai

src/scalar.rs

@@ -1658,9 +1658,24 @@ mod test {
         // encoding with high bit set, to check that the parser isn't pre-masking the high bit
         let non_canonical_bytes_because_highbit = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 128];
 
+        let canonical_l_minus_one = [237, 211, 245, 92, 26, 99, 18, 88, 214, 156, 247, 162, 222, 249, 222, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 15];
+        let canonical_zero = [0u8; 32];
+        let canonical_255_minus_1 = [132, 52, 71, 117, 71, 74, 127, 151, 35, 182, 58, 139, 233, 42, 231, 109, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 15];
+        let non_canonical_l = [237, 211, 245, 92, 26, 99, 18, 88, 214, 156, 247, 162, 222, 249, 222, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 16];
+        let non_canonical_l_plus_one = [237, 211, 245, 92, 26, 99, 18, 88, 214, 156, 247, 162, 222, 249, 222, 20, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 17];
+        let non_canonical_full = [0xFF; 32];
+        let non_canonical_255_minus_1 = [0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0b0111_1111];
+
         assert!( Scalar::from_canonical_bytes(canonical_bytes).is_some() );
+        assert!( Scalar::from_canonical_bytes(canonical_l_minus_one).is_some() );
+        assert!( Scalar::from_canonical_bytes(canonical_zero).is_some() );
+        assert!( Scalar::from_canonical_bytes(canonical_255_minus_1).is_some() );
         assert!( Scalar::from_canonical_bytes(non_canonical_bytes_because_unreduced).is_none() );
         assert!( Scalar::from_canonical_bytes(non_canonical_bytes_because_highbit).is_none() );
+        assert!( Scalar::from_canonical_bytes(non_canonical_l).is_none() );
+        assert!( Scalar::from_canonical_bytes(non_canonical_l_plus_one).is_none() );
+        assert!( Scalar::from_canonical_bytes(non_canonical_full).is_none() );
+        assert!( Scalar::from_canonical_bytes(non_canonical_255_minus_1).is_none() );
     }
 
     #[test]