Add tweak_vectors musig test

MetacoSA · Oct 4, 2022 · 602dea5 · 602dea5
1 parent fe7a177
commit 602dea5
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Showing 2 changed files with 45 additions and 1 deletion.
diff --git a/NBitcoin.Tests/Secp256k1Tests.cs b/NBitcoin.Tests/Secp256k1Tests.cs
@@ -4033,6 +4033,41 @@ public void musig_det_sign_vectors()
 			}
 		}
 
+		[Fact]
+		[Trait("UnitTest", "UnitTest")]
+		public void musig_tweak_vectors()
+		{
+			var root = JObject.Parse(File.ReadAllText("data/musig/tweak_vectors.json"));
+			var sk = new ECPrivKey(Encoders.Hex.DecodeData(root["sk"].Value<string>()), null);
+			var pubkeys = GetArray<string>(root["pubkeys"]).ToArray();
+			var secnonce = root["secnonce"].Value<string>();
+			var pnonces = GetArray<string>(root["pnonces"]).ToArray();
+			var ptweaks = GetArray<string>(root["tweaks"]).ToArray();
+			var msg = Encoders.Hex.DecodeData(root["msg"].Value<string>());
+			foreach (var item in (JArray)root["valid_test_cases"])
+			{
+				var keys = GetArray<int>(item["key_indices"]).Select(p => ECPubKey.Create(Encoders.Hex.DecodeData(pubkeys[p]))).ToArray();
+				var nonces = GetArray<int>(item["nonce_indices"]).Select(p => new MusigPubNonce(Encoders.Hex.DecodeData(pnonces[p]))).ToArray();
+				var tweaks = GetArray<int>(item["tweak_indices"]).Select(p => Encoders.Hex.DecodeData(ptweaks[p])).ToArray();
+				var is_xonly = GetArray<bool>(item["is_xonly"]);
+
+				var ctx = new MusigContext(keys, msg);
+				for (int i = 0; i < tweaks.Length; i++)
+				{
+					ctx.Tweak(tweaks[i], is_xonly[i]);
+				}
+				ctx.ProcessNonces(nonces);
+				var result = ctx.Sign(sk, ToMusigPrivNonce(secnonce));
+				AssertEx.EqualBytes(item["expected"].Value<string>(), result.ToBytes());
+			}
+		}
+
+		private MusigPrivNonce ToMusigPrivNonce(string hex)
+		{
+			var b = Encoders.Hex.DecodeData(hex);
+			return new MusigPrivNonce(ECPrivKey.Create(b.AsSpan().Slice(0, 32)),
+									  ECPrivKey.Create(b.AsSpan().Slice(32, 32)));
+		}
 
 		[Fact]
 		[Trait("UnitTest", "UnitTest")]

diff --git a/NBitcoin.Tests/data/musig/tweak_vectors.json b/NBitcoin.Tests/data/musig/tweak_vectors.json
@@ -48,14 +48,23 @@
             "expected": "408A0A21C4A0F5DACAF9646AD6EB6FECD7F7A11F03ED1F48DFFF2185BC2C2408",
             "comment": "A plain tweak followed by an x-only tweak"
         },
+        {
+            "key_indices": [1, 2, 0],
+            "nonce_indices": [1, 2, 0],
+            "tweak_indices": [0, 1, 2, 3],
+            "is_xonly": [false, false, true, true],
+            "signer_index": 2,
+            "expected": "45ABD206E61E3DF2EC9E264A6FEC8292141A633C28586388235541F9ADE75435",
+            "comment": "Four tweaks: plain, plain, x-only, x-only."
+        },
         {
             "key_indices": [1, 2, 0],
             "nonce_indices": [1, 2, 0],
             "tweak_indices": [0, 1, 2, 3],
             "is_xonly": [true, false, true, false],
             "signer_index": 2,
             "expected": "B255FDCAC27B40C7CE7848E2D3B7BF5EA0ED756DA81565AC804CCCA3E1D5D239",
-            "comment": "Four tweaks: x-only, plain, x-only, plain"
+            "comment": "Four tweaks: x-only, plain, x-only, plain. If an implementation prohibits applying plain tweaks after x-only tweaks, it can skip this test vector or return an error."
         }
     ],
     "error_test_cases": [