Use p2sh for multi sig stealth address payment

NBitcoin.Tests/transaction_tests.cs

@@ -313,12 +313,6 @@ private void AssertHasAsset(Transaction tx, ColoredTransaction colored, ColoredE
 		[Fact]
 		[Trait("UnitTest", "UnitTest")]
 		public void CanBuildStealthTransaction()
-		{
-			CanBuildStealthTransactionCore(false);
-			CanBuildStealthTransactionCore(true);
-		}
-
-		void CanBuildStealthTransactionCore(bool p2sh)
 		{
 			var stealthKeys = Enumerable.Range(0, 3).Select(_ => new Key()).ToArray();
 			var scanKey = new Key();
@@ -339,12 +333,12 @@ void CanBuildStealthTransactionCore(bool p2sh)
 				builder
 				.AddCoins(coins)
 				.AddKeys(bob)
-				.Send(darkSatoshi, "1.00", p2sh: p2sh)
+				.Send(darkSatoshi, "1.00")
 				.BuildTransaction(true);
 			Assert.True(builder.Verify(tx));
 
 			//Satoshi scans a StealthCoin in the transaction with his scan key
-			var stealthCoin = StealthCoin.Find(tx, darkSatoshi, scanKey, allowP2sh: p2sh);
+			var stealthCoin = StealthCoin.Find(tx, darkSatoshi, scanKey);
 			Assert.NotNull(stealthCoin);
 
 			//Satoshi sends back the money to Bob

NBitcoin/Coin.cs

@@ -288,11 +288,10 @@ public Script Redeem
 		/// <param name="tx">The transaction to scan</param>
 		/// <param name="address">The stealth address</param>
 		/// <param name="scan">The scan private key</param>
-		/// <param name="allowP2sh">Support P2SH stealth payment, this weaken the scanner to DDOS attacks</param>
 		/// <returns></returns>
-		public static StealthCoin Find(Transaction tx, BitcoinStealthAddress address, Key scan, bool allowP2sh = false)
+		public static StealthCoin Find(Transaction tx, BitcoinStealthAddress address, Key scan)
 		{
-			var payment = address.GetPayments(tx, scan, allowP2sh).FirstOrDefault();
+			var payment = address.GetPayments(tx, scan).FirstOrDefault();
 			if(payment == null)
 				return null;
 			var txId = tx.GetHash();

NBitcoin/Scanning/StealthPaymentScanner.cs

@@ -39,7 +39,7 @@ public Key Scan
 
 		public override Coins ScanCoins(uint256 txId, Transaction tx, int height)
 		{
-			var payments = StealthPayment.GetPayments(tx, Address, Scan, false);
+			var payments = StealthPayment.GetPayments(tx, Address, Scan);
 			return new Coins(tx, txout => Match(txout, payments), height);
 		}
 

NBitcoin/Stealth/BitcoinStealthAddress.cs

@@ -110,9 +110,9 @@ public bool Match(StealthMetadata metadata)
 			return Match(metadata.BitField);
 		}
 
-		public StealthPayment[] GetPayments(Transaction transaction, bool allowP2sh = false)
+		public StealthPayment[] GetPayments(Transaction transaction)
 		{
-			return StealthPayment.GetPayments(transaction, null, null, allowP2sh);
+			return StealthPayment.GetPayments(transaction, null, null);
 		}
 	}
 	public class BitcoinStealthAddress : Base58Data
@@ -235,20 +235,19 @@ public override Base58Type Type
 		/// <param name="tx">The transaction to scan</param>
 		/// <param name="address">The stealth address</param>
 		/// <param name="scan">The scan private key</param>
-		/// <param name="allowP2sh">Support P2SH stealth payment, this weaken the scanner to DDOS attacks</param>
 		/// <returns></returns>
-		public StealthPayment[] GetPayments(Transaction transaction, Key scanKey, bool allowP2sh = false)
+		public StealthPayment[] GetPayments(Transaction transaction, Key scanKey)
 		{
-			return StealthPayment.GetPayments(transaction, this, scanKey, allowP2sh);
+			return StealthPayment.GetPayments(transaction, this, scanKey);
 		}
 
-		public StealthPayment CreatePayment(Key ephemKey = null, bool p2sh = false)
+		public StealthPayment CreatePayment(Key ephemKey = null)
 		{
 			if(ephemKey == null)
 				ephemKey = new Key();
 
 			var metadata = StealthMetadata.CreateMetadata(ephemKey, this.Prefix);
-			return new StealthPayment(this, ephemKey, metadata, p2sh);
+			return new StealthPayment(this, ephemKey, metadata);
 		}
 
 

NBitcoin/Stealth/StealthPayment.cs

@@ -41,11 +41,12 @@ public BitcoinAddress GetAddress(Network network)
 
 	public class StealthPayment
 	{
-		public StealthPayment(BitcoinStealthAddress address, Key ephemKey, StealthMetadata metadata, bool p2sh)
+		public StealthPayment(BitcoinStealthAddress address, Key ephemKey, StealthMetadata metadata)
 		{
 			Metadata = metadata;
 			ScriptPubKey = CreatePaymentScript(address.SignatureCount, address.SpendPubKeys, ephemKey, address.ScanPubKey);
-			if(p2sh)
+
+			if(address.SignatureCount > 1)
 			{
 				Redeem = ScriptPubKey;
 				ScriptPubKey = ScriptPubKey.ID.CreateScriptPubKey();
@@ -140,7 +141,7 @@ public void AddToTransaction(Transaction transaction, Money value)
 			transaction.Outputs.Add(new TxOut(value, ScriptPubKey));
 		}
 
-		public static StealthPayment[] GetPayments(Transaction transaction, BitcoinStealthAddress address, Key scan, bool allowP2sh = false)
+		public static StealthPayment[] GetPayments(Transaction transaction, BitcoinStealthAddress address, Key scan)
 		{
 			List<StealthPayment> result = new List<StealthPayment>();
 			for(int i = 0 ; i < transaction.Outputs.Count - 1 ; i++)
@@ -155,8 +156,6 @@ public static StealthPayment[] GetPayments(Transaction transaction, BitcoinSteal
 
 					if(scriptId != null)
 					{
-						if(!allowP2sh)
-							continue;
 						if(address == null)
 							throw new ArgumentNullException("address");
 						redeem = CreatePaymentScript(address, metadata.EphemKey, scan);

NBitcoin/TransactionBuilder.cs

@@ -465,7 +465,7 @@ private void AssertOpReturn(string name)
 			}
 		}
 
-		public TransactionBuilder Send(BitcoinStealthAddress address, Money money, Key ephemKey = null, bool p2sh = false)
+		public TransactionBuilder Send(BitcoinStealthAddress address, Money money, Key ephemKey = null)
 		{
 			if(_OpReturnUser == null)
 				_OpReturnUser = "Stealth Payment";
@@ -474,7 +474,7 @@ public TransactionBuilder Send(BitcoinStealthAddress address, Money money, Key e
 
 			CurrentGroup.Builders.Add(ctx =>
 			{
-				var payment = address.CreatePayment(ephemKey, p2sh);
+				var payment = address.CreatePayment(ephemKey);
 				payment.AddToTransaction(ctx.Transaction, money);
 				return money;
 			});