private MemoryStream modifyDataRow(DataRowMessage dataRow, RowDescriptionMessage rowDescription)
{
Func <string, string> maskingFunction;
var ms = new MemoryStream();
ms.Write(EndianHelpers.ToBigE(dataRow.NumFields));
int i = 0;
foreach (var f in dataRow.DataRowFields)
{
uint tableOid = rowDescription.FieldDescriptions[i].ObjectId;
string columnName = rowDescription.FieldDescriptions[i].FieldName;
uint dataTypeOid = rowDescription.FieldDescriptions[i].DataTypeObjectId;
//If the column vale is null or we are preserving keyed column values and the column is either a primary or foreign key.
if (f.ColumnValueLength == -1 || (_state._maskingModel.PreserveKeys && _state.isColumnKeyed(tableOid, columnName)))
{
ms.Write(EndianHelpers.ToBigE(f.ColumnValueLength));
ms.Write(f.ColumnValue);
}
else
{
maskingFunction = getMaskingFunction(tableOid, dataTypeOid, columnName);
string rowValue = System.Text.Encoding.UTF8.GetString(f.ColumnValue);
byte[] newBytes = System.Text.Encoding.UTF8.GetBytes(maskingFunction(rowValue));
byte[] newLength = EndianHelpers.ToBigE(newBytes.Length);
ms.Write(newLength);
ms.Write(newBytes);
}
i++;
}
return(ms);
}
private void OnDataReceiveFromClient(IAsyncResult result)
{
var state = (State)result.AsyncState;
try
{
var bytesRead = state.ClientSocket.EndReceive(result);
if (bytesRead > 0)
{
//here we check to see if front end has sent an SSLRequest message.
//TODO: Currently, we assume the SSLRequest will come in a single buffer read. If the message were to come in two or more reads we would miss it.
if (EndianHelpers.SwapEndianness(BitConverter.ToUInt32(state.ClientBuffer, 0)) == 8 && EndianHelpers.SwapEndianness(BitConverter.ToUInt32(state.ClientBuffer, 4)) == 80877103)
{
Console.WriteLine("Client has made SSLRequest. This is not supported.");
_inProcessOfNegotiatingSSL = true;
}
//do nothing for now. Add logic here to parse FrontEnd requests.
state.DatabaseSocket.Send(state.ClientBuffer, bytesRead, SocketFlags.None);
state.ClientSocket.BeginReceive(state.ClientBuffer, 0, state.ClientBuffer.Length, 0, OnDataReceiveFromClient, state);
}
}
catch
{
state.ClientSocket.Close();
state.DatabaseSocket.Close();
_resetStatemachine();
}
}
private void handleRowDescription(byte[] buffer, int offset, int messageLength)
{
ushort numFields = EndianHelpers.SwapEndianness(BitConverter.ToUInt16(buffer, offset));
offset += 2;
currentRowDescription = new RowDescriptionMessage();
currentRowDescription.NumFields = numFields;
currentRowDescription.FieldDescriptions = new List <RowDescriptionField>();
for (int i = 0; i < numFields; i++)
{
RowDescriptionField df = new RowDescriptionField();
int z = offset;
while (buffer[z] != 0)
{
z++;
}
string fieldName = Encoding.ASCII.GetString(buffer, offset, z - offset);
offset = z + 1; //we add 1 because string will end with a null.
df.FieldName = fieldName;
uint objectId = EndianHelpers.SwapEndianness(BitConverter.ToUInt32(buffer, offset));
offset += 4;
df.ObjectId = objectId;
ushort attrId = EndianHelpers.SwapEndianness(BitConverter.ToUInt16(buffer, offset));
offset += 2;
df.AttrId = attrId;
uint dataTypeObjectId = EndianHelpers.SwapEndianness(BitConverter.ToUInt32(buffer, offset));
offset += 4;
df.DataTypeObjectId = dataTypeObjectId;
ushort dataTypeSize = EndianHelpers.SwapEndianness(BitConverter.ToUInt16(buffer, offset));
offset += 2;
df.DataTypeSize = dataTypeSize;
uint typeModifier = EndianHelpers.SwapEndianness(BitConverter.ToUInt32(buffer, offset));
offset += 4;
df.TypeModifier = typeModifier;
ushort formatCode = EndianHelpers.SwapEndianness(BitConverter.ToUInt16(buffer, offset));
offset += 2;
df.FormatCode = formatCode;
currentRowDescription.FieldDescriptions.Add(df);
}
var shouldModify = _shouldModifyTable(currentRowDescription.FieldDescriptions.First().ObjectId);
currentRowDescription.ShouldModify = shouldModify;
}
private byte[] handleDataRow(byte[] buffer, int messageLength)
{
var dataRow = new DataRowMessage();
int offset = 5; //1 byte for message type and 4 bytes for the int32 that states the length.
ushort numFields = EndianHelpers.SwapEndianness(BitConverter.ToUInt16(buffer, 5));
dataRow.NumFields = numFields;
if (numFields != 0)
{
dataRow.DataRowFields = new List <DataRowField>(numFields);
}
offset += 2;
for (int i = 0; i < numFields; i++)
{
var dataRowField = new DataRowField();
int columnValueLength = IPAddress.NetworkToHostOrder(BitConverter.ToInt32(buffer, offset));
dataRowField.ColumnValueLength = columnValueLength;
offset += 4;
if (columnValueLength != -1)
{
dataRowField.ColumnValue = new byte[columnValueLength];
Buffer.BlockCopy(buffer, offset, dataRowField.ColumnValue, 0, columnValueLength);
var colValue = Encoding.ASCII.GetString(buffer, offset, columnValueLength);
offset += columnValueLength;
}
dataRow.DataRowFields.Add(dataRowField);
}
var modifiedResultStream = _modifyDataRow(dataRow, currentRowDescription);
modifiedResultStream.Seek(0, SeekOrigin.Begin);
var message = new byte[modifiedResultStream.Length + 5];
message[0] = buffer[0];
var newLength = EndianHelpers.ToBigE((int)modifiedResultStream.Length + 4);
message[1] = newLength[0];
message[2] = newLength[1];
message[3] = newLength[2];
message[4] = newLength[3];
modifiedResultStream.Read(message, 5, (int)modifiedResultStream.Length);
return(message);
}
private int getMessageLength(byte[] buffer)
{
return((int)EndianHelpers.SwapEndianness(BitConverter.ToUInt32(buffer)));
}
