Allow plugin name without null terminator. Fixes #351

Author: bgrainger

src/MySqlConnector/ByteArrayReader.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 
 namespace MySql.Data
 {
@@ -104,6 +104,19 @@ public byte[] ReadNullTerminatedByteString()
 			return substring;
 		}
 
+		public byte[] ReadNullOrEofTerminatedByteString()
+		{
+			int index = m_offset;
+			while (index < m_maxOffset && m_buffer[index] != 0)
+				index++;
+			byte[] substring = new byte[index - m_offset];
+			Buffer.BlockCopy(m_buffer, m_offset, substring, 0, substring.Length);
+			if (index < m_maxOffset && m_buffer[index] == 0)
+				index++;
+			m_offset = index;
+			return substring;
+		}
+
 		public byte[] ReadByteString(int length)
 		{
 			VerifyRead(length);

src/MySqlConnector/Serialization/InitialHandshakePacket.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Text;
 
 namespace MySql.Data.Serialization
@@ -36,8 +36,10 @@ internal InitialHandshakePacket(ByteArrayReader reader)
 					AuthPluginData = concatenated;
 				}
 				if ((ProtocolCapabilities & ProtocolCapabilities.PluginAuth) != 0)
-					AuthPluginName = Encoding.UTF8.GetString(reader.ReadNullTerminatedByteString());
+					AuthPluginName = Encoding.UTF8.GetString(reader.ReadNullOrEofTerminatedByteString());
 			}
+			if (reader.BytesRemaining != 0)
+				throw new FormatException("Extra bytes at end of payload.");
 		}
 
 		const byte c_protocolVersion = 0x0A;

tests/MySqlConnector.Tests/ConnectionTests.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Data;
 using System.Diagnostics;
 using System.Threading;
 using System.Threading.Tasks;
@@ -117,6 +118,17 @@ public void LeakReaders()
 			}
 		}
 
+		[Fact]
+		public void AuthPluginNameNotNullTerminated()
+		{
+			m_server.SuppressAuthPluginNameTerminatingNull = true;
+			using (var connection = new MySqlConnection(m_csb.ConnectionString))
+			{
+				connection.Open();
+				Assert.Equal(ConnectionState.Open, connection.State);
+			}
+		}
+
 		private static async Task WaitForConditionAsync<T>(T expected, Func<T> getValue)
 		{
 			var sw = Stopwatch.StartNew();

tests/MySqlConnector.Tests/FakeMySqlServer.cs

@@ -1,4 +1,4 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.Net;
 using System.Net.Sockets;
@@ -45,6 +45,8 @@ public void Stop()
 
 		public string ServerVersion { get; set; } = "5.7.10-test";
 
+		public bool SuppressAuthPluginNameTerminatingNull { get; set; }
+
 		internal void ClientDisconnected() => Interlocked.Decrement(ref m_activeConnections);
 
 		private async Task AcceptConnectionsAsync()

tests/MySqlConnector.Tests/FakeMySqlServerConnection.cs

@@ -170,7 +170,9 @@ private void WriteInitialHandshake(BinaryWriter writer)
 			writer.Write(authData, 8, authData.Length - 8);
 			if (authData.Length - 8 < 13)
 				writer.Write(new byte[13 - (authData.Length - 8)]); // have to write at least 13 bytes
-			writer.WriteNullTerminated("mysql_native_password");
+			writer.Write(Encoding.UTF8.GetBytes("mysql_native_password"));
+			if (!m_server.SuppressAuthPluginNameTerminatingNull)
+				writer.Write((byte) 0);
 		}
 
 		private static void WriteOk(BinaryWriter writer)