Oracle: P2P Response Signature Message (neo-project#1553)

* Oracle Response Signature P2P

* caches

* rename private fields

* remove comments

* remove more comments and fix size

* Clean code

Co-authored-by: Shargon <shargon@gmail.com>

src/neo/Network/P2P/MessageCommand.cs

@@ -40,6 +40,8 @@ public enum MessageCommand : byte
         Block = 0x2c,
         [ReflectionCache(typeof(ConsensusPayload))]
         Consensus = 0x2d,
+        [ReflectionCache(typeof(OraclePayload))]
+        Oracle = 0x2e,
         Reject = 0x2f,
 
         //SPV protocol
@@ -52,6 +54,6 @@ public enum MessageCommand : byte
         MerkleBlock = 0x38,
 
         //others
-        Alert = 0x40,
+        Alert = 0x40
     }
 }

src/neo/Network/P2P/Payloads/OraclePayload.cs

@@ -0,0 +1,134 @@
+using Neo.IO;
+using System.IO;
+using Neo.Cryptography;
+using Neo.Cryptography.ECC;
+using Neo.Persistence;
+using System;
+using System.Linq;
+using Neo.SmartContract;
+using Neo.SmartContract.Native;
+
+namespace Neo.Network.P2P.Payloads
+{
+    public class OraclePayload : IVerifiable
+    {
+        private byte[] _data;
+        public byte[] Data
+        {
+            get => _data;
+            set { _data = value; _hash = null; _size = 0; }
+        }
+
+        private ECPoint _oraclePub;
+        public ECPoint OraclePub
+        {
+            get => _oraclePub;
+            set { _oraclePub = value; _hash = null; _size = 0; }
+        }
+
+        private Witness _witness;
+        public Witness Witness
+        {
+            get => _witness;
+            set { _witness = value; _hash = null; _size = 0; }
+        }
+
+        private int _size;
+        public int Size
+        {
+            get
+            {
+                if (_size == 0)
+                {
+                    _size = Data.GetVarSize() + //Data
+                        OraclePub.Size +        //Oracle Public key
+                        Witness.Size;           //Witness
+                }
+                return _size;
+            }
+        }
+
+        private UInt256 _hash = null;
+        public UInt256 Hash
+        {
+            get
+            {
+                if (_hash == null)
+                {
+                    _hash = new UInt256(Crypto.Hash256(this.GetHashData()));
+                }
+                return _hash;
+            }
+        }
+
+        public Witness[] Witnesses
+        {
+            get => new[] { Witness };
+            set
+            {
+                if (value.Length != 1) throw new ArgumentException();
+                Witness = value[0];
+            }
+        }
+
+        private OracleResponseSignature _deserializedOracleSignature = null;
+        public OracleResponseSignature OracleSignature
+        {
+            get
+            {
+                if (_deserializedOracleSignature is null)
+                    _deserializedOracleSignature = OracleResponseSignature.DeserializeFrom(Data);
+                return _deserializedOracleSignature;
+            }
+            internal set
+            {
+                if (!ReferenceEquals(_deserializedOracleSignature, value))
+                {
+                    _deserializedOracleSignature = value;
+                    Data = value?.ToArray();
+                }
+            }
+        }
+
+        public OracleResponseSignature GetDeserializedOracleSignature()
+        {
+            return OracleSignature;
+        }
+
+        void ISerializable.Deserialize(BinaryReader reader)
+        {
+            ((IVerifiable)this).DeserializeUnsigned(reader);
+            Witness = reader.ReadSerializable<Witness>();
+        }
+        void IVerifiable.DeserializeUnsigned(BinaryReader reader)
+        {
+            Data = reader.ReadVarBytes(Transaction.MaxTransactionSize);
+            OraclePub = reader.ReadSerializable<ECPoint>();
+        }
+
+        public virtual void Serialize(BinaryWriter writer)
+        {
+            ((IVerifiable)this).SerializeUnsigned(writer);
+            writer.Write(new Witness[] { Witness });
+        }
+
+        void IVerifiable.SerializeUnsigned(BinaryWriter writer)
+        {
+            writer.Write(Data);
+            writer.Write(OraclePub);
+        }
+
+        UInt160[] IVerifiable.GetScriptHashesForVerifying(StoreView snapshot)
+        {
+            return new[] { Contract.CreateSignatureRedeemScript(OraclePub).ToScriptHash() };
+        }
+
+        public bool Verify(StoreView snapshot)
+        {
+            ECPoint[] validators = NativeContract.Oracle.GetOracleValidators(snapshot);
+            if (!validators.Any(u => u.Equals(OraclePub)))
+                return false;
+            return this.VerifyWitnesses(snapshot, 0_02000000);
+        }
+    }
+}

src/neo/Network/P2P/Payloads/OracleResponseSignature.cs

@@ -0,0 +1,110 @@
+using Neo.Cryptography;
+using Neo.IO;
+using System;
+using System.IO;
+using System.Linq;
+using System.Text;
+
+namespace Neo.Network.P2P.Payloads
+{
+    public class OracleResponseSignature : ISerializable
+    {
+        private const byte ResponseSignatureType = 0x01;
+
+        private UInt256 _transactionRequestHash;
+        public UInt256 TransactionRequestHash
+        {
+            get => _transactionRequestHash;
+            set { _transactionRequestHash = value; _hash = null; _size = 0; }
+        }
+
+        private UInt256 _oracleExecutionCacheHash;
+        public UInt256 OracleExecutionCacheHash
+        {
+            get => _oracleExecutionCacheHash;
+            set { _oracleExecutionCacheHash = value; _hash = null; _size = 0; }
+        }
+
+        /// <summary>
+        /// Signature for the oracle response tx for this public key
+        /// </summary>
+        private byte[] _signature;
+        public byte[] Signature
+        {
+            get => _signature;
+            set
+            {
+                if (value.Length != 64) throw new ArgumentException();
+                _signature = value;
+                _hash = null;
+                _size = 0;
+            }
+        }
+
+        private int _size;
+        public int Size
+        {
+            get
+            {
+                if (_size == 0)
+                {
+                    _size = sizeof(byte) +  //Type
+                        UInt256.Length +    //Transaction Hash
+                        UInt256.Length +    //OracleExecutionCache Hash
+                        Signature.Length;   //Oracle Validator Signature
+                }
+                return _size;
+            }
+        }
+
+        private UInt256 _hash = null;
+        public UInt256 Hash
+        {
+            get
+            {
+                if (_hash == null)
+                {
+                    _hash = new UInt256(Crypto.Hash256(this.ToArray()));
+                }
+                return _hash;
+            }
+        }
+
+        public virtual void Deserialize(BinaryReader reader)
+        {
+            if (reader.ReadByte() != ResponseSignatureType) throw new FormatException();
+            DeserializeWithoutType(reader);
+        }
+
+        private void DeserializeWithoutType(BinaryReader reader)
+        {
+            TransactionRequestHash = reader.ReadSerializable<UInt256>();
+            OracleExecutionCacheHash = reader.ReadSerializable<UInt256>();
+            Signature = reader.ReadFixedBytes(64);
+        }
+
+        public static OracleResponseSignature DeserializeFrom(byte[] data)
+        {
+            switch (data[0])
+            {
+                case ResponseSignatureType:
+                    {
+                        using BinaryReader reader = new BinaryReader(new MemoryStream(data, 1, data.Length - 1), Encoding.UTF8, false);
+
+                        var ret = new OracleResponseSignature();
+                        ret.DeserializeWithoutType(reader);
+                        return ret;
+                    }
+                default: throw new FormatException();
+            }
+        }
+
+        public virtual void Serialize(BinaryWriter writer)
+        {
+            writer.Write(ResponseSignatureType);
+            writer.Write(TransactionRequestHash);
+            writer.Write(OracleExecutionCacheHash);
+            writer.Write(Signature);
+        }
+    }
+}