Add MmimbleWimble support

Implemented parsing and creation of MimbleWimble transactions,
as well as Wallet type for keeping track of unspent coins.
Added tests for implemented functionality.

.gitignore

@@ -7,3 +7,5 @@
 /src/NLitecoin/bin
 /tests/NLitecoin.Tests/obj
 /tests/NLitecoin.Tests/bin
+/tests/NLitecoin.MimbleWimble.Tests/obj
+/tests/NLitecoin.MimbleWimble.Tests/bin

NLitecoin.sln

@@ -3,9 +3,11 @@ Microsoft Visual Studio Solution File, Format Version 12.00
 # Visual Studio Version 17
 VisualStudioVersion = 17.6.33829.357
 MinimumVisualStudioVersion = 10.0.40219.1
-Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "NLitecoin", "src\NLitecoin\NLitecoin.fsproj", "{1128287F-0435-4FA9-B4DD-420A9E1FDB23}"
+Project("{6EC3EE1D-3C4E-46DD-8F32-0CC8E7565705}") = "NLitecoin", "src\NLitecoin\NLitecoin.fsproj", "{1128287F-0435-4FA9-B4DD-420A9E1FDB23}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "NLitecoin.Tests", "tests\NLitecoin.Tests\NLitecoin.Tests.csproj", "{F954D3AC-36BC-483E-8DB1-4CC65DF1694D}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "NLitecoin.Tests", "tests\NLitecoin.Tests\NLitecoin.Tests.csproj", "{F954D3AC-36BC-483E-8DB1-4CC65DF1694D}"
+EndProject
+Project("{F2A71F9B-5D33-465A-A702-920D77279786}") = "NLitecoin.MimbleWimble.Tests", "tests\NLitecoin.MimbleWimble.Tests\NLitecoin.MimbleWimble.Tests.fsproj", "{6A67D54D-BE2C-449F-88D2-D6739A5F3F89}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -21,6 +23,10 @@ Global
 		{F954D3AC-36BC-483E-8DB1-4CC65DF1694D}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{F954D3AC-36BC-483E-8DB1-4CC65DF1694D}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{F954D3AC-36BC-483E-8DB1-4CC65DF1694D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6A67D54D-BE2C-449F-88D2-D6739A5F3F89}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6A67D54D-BE2C-449F-88D2-D6739A5F3F89}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6A67D54D-BE2C-449F-88D2-D6739A5F3F89}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6A67D54D-BE2C-449F-88D2-D6739A5F3F89}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

src/NLitecoin/Litecoin.fs

@@ -21,7 +21,7 @@ type internal Witness(inputs: TxInList) =
                         | null -> WitScript.Empty
                         | witScript -> witScript
                     script.ToBytes()
-                stream.ReadWrite(ref bytes)
+                stream.ReadWrite bytes
             else
                 input.WitScript <- WitScript.Load stream
 
@@ -50,10 +50,14 @@ module private TxListExtensions =
 type LitecoinTransaction() = 
     inherit Transaction()
 
+    static let mwebExtensionTxFlag = 8uy
+
+    member val MimbleWimbleTransaction: Option<MimbleWimble.Transaction> = None with get, set
+
     override self.GetConsensusFactory() = LitecoinConsensusFactory.Instance
 
     member private self.Read (stream: BitcoinStream) (witSupported: bool) =
-        let flags = 0uy
+        let mutable flags = 0uy
         self.nVersion <- stream.ReadWrite self.nVersion
         // Try to read the vin. In case the dummy is there, this will be read as an empty vector.
         stream.ReadWrite(&self.vin)
@@ -64,7 +68,7 @@ type LitecoinTransaction() =
 
         if self.vin.Count = 0 && witSupported && not hasNoDummy then
             // We read a dummy or an empty vin.
-            let flags = stream.ReadWrite flags
+            flags <- stream.ReadWrite flags
             if flags <> 0uy then
                 // Assume we read a dummy and a flag.
                 stream.ReadWrite(&self.vin)
@@ -79,22 +83,17 @@ type LitecoinTransaction() =
             stream.ReadWrite(&self.vout)
             self.vout <- self.vout.WithTransaction self
 
-        let flags =
-            if ((flags &&& 1uy) <> 0uy) && witSupported then
-                // The witness flag is present, and we support witnesses.
-                let wit = Witness self.Inputs
-                wit.ReadWrite stream
-                flags ^^^ 1uy
-            else
-                flags
-        let flags =
-            if (flags &&& 8uy) <> 0uy then //MWEB extension tx flag
-                (* The MWEB flag is present, but currently no MWEB data is supported. 
-                    * This fix just prevent from throwing exception bellow so cannonical litecoin transaction can be read
-                    *)
-                flags ^^^ 8uy
-            else
-                flags
+        if ((flags &&& 1uy) <> 0uy) && witSupported then
+            // The witness flag is present, and we support witnesses.
+            let wit = Witness self.Inputs
+            wit.ReadWrite stream
+            flags <- flags ^^^ 1uy
+
+        if (flags &&& mwebExtensionTxFlag) <> 0uy then
+            let version = ref 0uy
+            stream.ReadWrite version
+            self.MimbleWimbleTransaction <- Some(MimbleWimble.Transaction.Read stream)
+            flags <- flags ^^^ 8uy
 
         if flags <> 0uy then
             // Unknown flag in the serialization
@@ -118,6 +117,12 @@ type LitecoinTransaction() =
             else
                 0uy
 
+        let flags = 
+            if self.MimbleWimbleTransaction.IsSome then 
+                flags ||| mwebExtensionTxFlag 
+            else 
+                flags 
+
         let flags = 
             if flags <> 0uy then
                 // Use extended format in case witnesses are to be serialized.
@@ -135,6 +140,12 @@ type LitecoinTransaction() =
             let wit = Witness self.Inputs
             wit.ReadWrite stream
 
+        match self.MimbleWimbleTransaction with
+        | Some mwebTransaction -> 
+            stream.ReadWrite MimbleWimble.Transaction.Version |> ignore
+            (mwebTransaction :> MimbleWimble.ISerializeable).Write stream
+        | None -> ()
+
     override self.ReadWrite(stream: BitcoinStream) =
         let witSupported = 
             (((uint32 stream.TransactionOptions) &&& (uint32 TransactionOptions.Witness)) <> 0u) &&