Read Fixed

src/neo/Consensus/Commit.cs

@@ -1,3 +1,4 @@
+using Neo.IO;
 using System.IO;
 
 namespace Neo.Consensus
@@ -13,7 +14,7 @@ public class Commit : ConsensusMessage
         public override void Deserialize(BinaryReader reader)
         {
             base.Deserialize(reader);
-            Signature = reader.ReadBytes(64);
+            Signature = reader.ReadFixedBytes(64);
         }
 
         public override void Serialize(BinaryWriter writer)

src/neo/Consensus/RecoveryMessage.CommitPayloadCompact.cs

@@ -23,7 +23,7 @@ void ISerializable.Deserialize(BinaryReader reader)
             {
                 ViewNumber = reader.ReadByte();
                 ValidatorIndex = reader.ReadUInt16();
-                Signature = reader.ReadBytes(64);
+                Signature = reader.ReadFixedBytes(64);
                 InvocationScript = reader.ReadVarBytes(1024);
             }
 

src/neo/Consensus/RecoveryMessage.cs

@@ -39,7 +39,7 @@ public override void Deserialize(BinaryReader reader)
             {
                 int preparationHashSize = UInt256.Zero.Size;
                 if (preparationHashSize == (int)reader.ReadVarInt((ulong)preparationHashSize))
-                    PreparationHash = new UInt256(reader.ReadBytes(preparationHashSize));
+                    PreparationHash = new UInt256(reader.ReadFixedBytes(preparationHashSize));
             }
 
             PreparationMessages = reader.ReadSerializableArray<PreparationPayloadCompact>(Blockchain.MaxValidators).ToDictionary(p => (int)p.ValidatorIndex);

src/neo/IO/Helper.cs

@@ -151,7 +151,7 @@ public static byte[] ReadBytesWithGrouping(this BinaryReader reader)
                 int count;
                 do
                 {
-                    byte[] group = reader.ReadBytes(GroupingSizeInBytes);
+                    byte[] group = reader.ReadFixedBytes(GroupingSizeInBytes);
                     count = reader.ReadByte();
                     if (count > GroupingSizeInBytes)
                         throw new FormatException();
@@ -162,9 +162,30 @@ public static byte[] ReadBytesWithGrouping(this BinaryReader reader)
             }
         }
 
+        public static byte[] ReadFixedBytes(this BinaryReader reader, int size)
+        {
+            var index = 0;
+            var data = new byte[size];
+
+            while (size > 0)
+            {
+                var bytesRead = reader.Read(data, index, size);
+
+                if (bytesRead <= 0)
+                {
+                    throw new FormatException();
+                }
+
+                size -= bytesRead;
+                index += bytesRead;
+            }
+
+            return data;
+        }
+
         public static string ReadFixedString(this BinaryReader reader, int length)
         {
-            byte[] data = reader.ReadBytes(length);
+            byte[] data = reader.ReadFixedBytes(length);
             return Encoding.UTF8.GetString(data.TakeWhile(p => p != 0).ToArray());
         }
 
@@ -196,7 +217,7 @@ public static T[] ReadSerializableArray<T>(this BinaryReader reader, int max = 0
 
         public static byte[] ReadVarBytes(this BinaryReader reader, int max = 0x1000000)
         {
-            return reader.ReadBytes((int)reader.ReadVarInt((ulong)max));
+            return reader.ReadFixedBytes((int)reader.ReadVarInt((ulong)max));
         }
 
         public static ulong ReadVarInt(this BinaryReader reader, ulong max = ulong.MaxValue)

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

@@ -31,8 +31,7 @@ void ISerializable.Deserialize(BinaryReader reader)
             Timestamp = reader.ReadUInt32();
 
             // Address
-            byte[] data = reader.ReadBytes(16);
-            if (data.Length != 16) throw new FormatException();
+            byte[] data = reader.ReadFixedBytes(16);
             Address = new IPAddress(data).Unmap();
 
             // Capabilities

tests/neo.UnitTests/Consensus/UT_Consensus.cs

@@ -531,8 +531,8 @@ public void TestSerializeAndDeserializeConsensusContext()
             consensusContext.CommitPayloads = new ConsensusPayload[consensusContext.Validators.Length];
             using (SHA256 sha256 = SHA256.Create())
             {
-                consensusContext.CommitPayloads[3] = MakeSignedPayload(consensusContext, new Commit { Signature = sha256.ComputeHash(testTx1.Hash.ToArray()) }, 3, new[] { (byte)'3', (byte)'4' });
-                consensusContext.CommitPayloads[6] = MakeSignedPayload(consensusContext, new Commit { Signature = sha256.ComputeHash(testTx2.Hash.ToArray()) }, 3, new[] { (byte)'6', (byte)'7' });
+                consensusContext.CommitPayloads[3] = MakeSignedPayload(consensusContext, new Commit { Signature = sha256.ComputeHash(testTx1.Hash.ToArray()).Concat(sha256.ComputeHash(testTx1.Hash.ToArray())).ToArray() }, 3, new[] { (byte)'3', (byte)'4' });
+                consensusContext.CommitPayloads[6] = MakeSignedPayload(consensusContext, new Commit { Signature = sha256.ComputeHash(testTx2.Hash.ToArray()).Concat(sha256.ComputeHash(testTx2.Hash.ToArray())).ToArray() }, 3, new[] { (byte)'6', (byte)'7' });
             }
 
             consensusContext.Block.Timestamp = TimeProvider.Current.UtcNow.ToTimestampMS();

tests/neo.UnitTests/IO/UT_IOHelper.cs

@@ -23,6 +23,40 @@ public void TestAsSerializableGeneric()
             Assert.AreEqual(UInt160.Zero, result);
         }
 
+        [TestMethod]
+        public void TestReadFixedBytes()
+        {
+            byte[] data = new byte[] { 0x01, 0x02, 0x03, 0x04 };
+
+            // Less data
+
+            using (var reader = new BinaryReader(new MemoryStream(data), Encoding.UTF8, false))
+            {
+                byte[] result = Neo.IO.Helper.ReadFixedBytes(reader, 3);
+
+                Assert.AreEqual("010203", result.ToHexString());
+                Assert.AreEqual(3, reader.BaseStream.Position);
+            }
+
+            // Same data
+
+            using (var reader = new BinaryReader(new MemoryStream(data), Encoding.UTF8, false))
+            {
+                byte[] result = Neo.IO.Helper.ReadFixedBytes(reader, 4);
+
+                Assert.AreEqual("01020304", result.ToHexString());
+                Assert.AreEqual(4, reader.BaseStream.Position);
+            }
+
+            // More data
+
+            using (var reader = new BinaryReader(new MemoryStream(data), Encoding.UTF8, false))
+            {
+                Assert.ThrowsException<FormatException>(() => Neo.IO.Helper.ReadFixedBytes(reader, 5));
+                Assert.AreEqual(4, reader.BaseStream.Position);
+            }
+        }
+
         [TestMethod]
         public void TestNullableArray()
         {