/// <summary>
/// Encodes a key-exchange-instruction
/// from client to server.
/// </summary>
/// <returns>The encoded string</returns>
private string EncodeKeyExchangeC2S()
{
StringBuilder innersb = new StringBuilder();
StringBuilder sb = new StringBuilder();
innersb.Append($"IID:{ID}$");
innersb.Append($"FWV:{FrameworkVersion}$");
innersb.Append($"ISV:{InstructionSetVersion}$");
innersb.Append($"PUK:{Sender?.RSAKeys.PublicKey}$");
innersb.Append($"USR:{Base64Handler.Encode(Sender?.Username)}$");
innersb.Append($"INS:{instruction}$");
sb.Append(innersb.ToString());
sb.Append("%");
return(sb.ToString());
}
/// <summary>
/// Encodes the message and returns it as a string.
/// </summary>
/// <returns>The encoded string</returns>
public string Encode()
{
if (this.GetType() == typeof(InstructionLibraryEssentials.KeyExchangeServer2Client))
{
return(EncodeKeyExchangeS2C());
}
if (this.GetType() == typeof(InstructionLibraryEssentials.KeyExchangeClient2Server))
{
return(EncodeKeyExchangeC2S());
}
bool rsaEncryption = false;
if (Receiver.RSAKeys.PublicKey != null)
{
rsaEncryption = true;
}
StringBuilder innersb = new StringBuilder();
StringBuilder sb = new StringBuilder();
if (rsaEncryption)
{
sb.Append("R:");
}
// Instruction-ID
innersb.Append($"IID:{ID}$");
// Version Data (Framework and instructionset)
innersb.Append($"FWV:{FrameworkVersion}$");
innersb.Append($"ISV:{InstructionSetVersion}$");
// User Data
if (Sender?.RSAKeys.PublicKey != null)
{
innersb.Append($"PUK:{Sender?.RSAKeys.PublicKey}$");
}
if (Sender?.Username != null)
{
innersb.Append($"USR:{Base64Handler.Encode(Sender?.Username)}$");
}
if (Sender?.Password != null)
{
if (rsaEncryption)
{
innersb.Append($"PSW:{RSAHandler.Encrypt(Receiver?.RSAKeys.PublicKey, Sender?.Password)}$");
}
else
{
innersb.Append($"PSW:{Base64Handler.Encode(Sender?.Password)}$");
}
}
// Signature
if (Sender?.RSAKeys.PrivateKey != null)
{
Guid signature = Guid.NewGuid();
innersb.Append($"SGP:{signature.ToString()}$");
innersb.Append($"SGC:{RSAHandler.Sign(Sender?.RSAKeys.PrivateKey, signature.ToString())}$");
}
// Actuall data
if (instruction != null)
{
innersb.Append($"INS:{instruction}$");
}
if (value != null)
{
innersb.Append($"VAL:{Base64Handler.Encode(value)}$");
}
if (parameters != null)
{
innersb.Append($"PAR:");
foreach (object param in parameters)
{
innersb.Append($"{param.GetType().AssemblyQualifiedName}#{Base64Handler.Encode(param.ToString())}|");
}
innersb.Append($"$");
}
sb.Append(innersb.ToString());
sb.Append("%");
return(sb.ToString());
}
/// <summary>
/// Parses an encoded instruction-string and returns
/// all instruction-objects included in the string.
/// </summary>
/// <param name="pLocalUser">Local user</param>
/// <param name="pReceptionSocket">Remote user, from which the instruction was received</param>
/// <param name="pInstructionString">Encoded instruction-string. Can contain multiple instructions.</param>
/// <param name="pServerClientList">Client-List for authentication (NetComServer only!)</param>
/// <returns></returns>
internal static IEnumerable <InstructionBase> Parse(NetComUser pLocalUser, Socket pReceptionSocket, string pInstructionString, ClientList pServerClientList = null)
{
// RSA:<Base64>;RSA:<Base64>;
List <InstructionBase> retInstr = new List <InstructionBase>();
lock (pLocalUser)
{
foreach (string encodedInstruction in pInstructionString.Split('%'))
{
if (string.IsNullOrEmpty(encodedInstruction))
{
continue;
}
string instructionID = null;
string frameworkVersion = null;
string instructionsetVersion = null;
string username = null;
string password = null;
string instruction = null;
string value = null;
List <object> parameters = new List <object>();
string signaturePlain = null;
string signatureRSA = null;
string publicKey = null;
NetComUser user = null;
// RSA:<Base64>
bool rsaEncoded = false;
string encInstr = encodedInstruction;
if (encInstr.StartsWith("R:"))
{
rsaEncoded = true;
encInstr = encInstr.Remove(0, 2);
}
// <Base64>
string decodedInstruction;
try
{
//decodedInstruction = Base64Handler.Decode(encInstr);
decodedInstruction = encInstr;
}
catch (Exception ex)
{
(pLocalUser as NetComOperator).Debug("Instruction-Parsing: Could not decode from Base64.", DebugType.Error);
if ((pLocalUser as NetComOperator).ShowExceptions)
{
(pLocalUser as NetComOperator).Debug($"({ex.GetType().Name}) {ex.Message}", DebugType.Exception);
}
continue;
}
// INS:B64,VAL:B64,PAR:B64#B64|B64#B64|,
foreach (string encodedInstrSegment in decodedInstruction.Split('$'))
{
if (string.IsNullOrEmpty(encodedInstrSegment))
{
continue;
}
// INS:B64 / PAR:B64#B64|B64#B64|
string[] encodedSegmentParts = encodedInstrSegment.Split(':');
switch (encodedSegmentParts[0])
{
case "IID": instructionID = encodedSegmentParts[1]; break;
case "FWV": frameworkVersion = encodedSegmentParts[1]; break;
case "ISV": instructionsetVersion = encodedSegmentParts[1]; break;
case "PUK": publicKey = encodedSegmentParts[1]; break;
case "USR": username = Base64Handler.Decode(encodedSegmentParts[1], "ERROR"); break;
case "PSW":
if (rsaEncoded)
{
password = RSAHandler.Decrypt(pLocalUser.RSAKeys.PrivateKey, encodedSegmentParts[1]);
}
break;
case "SGP": signaturePlain = encodedSegmentParts[1]; break;
case "SGC":
if (rsaEncoded)
{
signatureRSA = encodedSegmentParts[1];
}
break;
case "INS": instruction = encodedSegmentParts[1]; break;
case "VAL": value = Base64Handler.Decode(encodedSegmentParts[1], "ERROR"); break;
case "PAR":
foreach (string paramGroup in encodedSegmentParts[1].Split('|'))
{
if (string.IsNullOrEmpty(paramGroup))
{
continue;
}
string[] paramParts = paramGroup.Split('#');
string paramTypeStr = paramParts[0];
string paramValueStr = Base64Handler.Decode(paramParts[1], "ERROR");
Type paramType = Type.GetType(paramTypeStr);
try
{
object convParam = null;
TypeConverter converter = TypeDescriptor.GetConverter(paramType);
if (converter != null)
{
convParam = converter.ConvertFromString(paramValueStr);
}
else
{
convParam = null;
}
parameters.Add(convParam);
}
catch (NotSupportedException ex)
{
(pLocalUser as NetComOperator).Debug("Broadcast-Error.", DebugType.Error);
if ((pLocalUser as NetComOperator).ShowExceptions)
{
(pLocalUser as NetComOperator).Debug($"({ex.GetType().Name}) {ex.Message}", DebugType.Exception);
}
throw new NetComParsingException($"*** Could not parse the following parameter: Type: {paramTypeStr}, Value: {paramValueStr} ***");
}
}
break;
}
}
// Check if the instruction has been processed before
if (instruction != typeof(InstructionLibraryEssentials.ReceptionConfirmation).AssemblyQualifiedName)
{
if ((pLocalUser as NetComOperator).InstructionLogIncomming.Contains(instructionID))
{
if (pLocalUser.GetType() == typeof(NetComClient))
{
(pLocalUser as NetComClient).Send(new InstructionLibraryEssentials.ReceptionConfirmation(pLocalUser, null, instructionID));
}
if (pLocalUser.GetType() == typeof(NetComServer))
{
(pLocalUser as NetComServer).Send(new InstructionLibraryEssentials.ReceptionConfirmation(pLocalUser, (pLocalUser as NetComServer).ConnectedClients[pReceptionSocket], instructionID));
}
continue;
}
}
// Check instructionset-version
if (ForceInstructionsetVersion && InstructionBase.InstructionSetVersion != instructionsetVersion)
{
throw new NetComVersionException($"*** The received package uses a different verion of the Instruction-Set! Local version: {InstructionBase.InstructionSetVersion} - Senders version: {instructionsetVersion} ***");
}
// Check framework-version
if (ForceFrameworkVersion && InstructionBase.FrameworkVersion != frameworkVersion)
{
throw new NetComVersionException($"*** The received package was built using a different verion of the Framework! Local version: {InstructionBase.FrameworkVersion} - Senders version: {frameworkVersion} ***");
}
// Check signature
if (rsaEncoded && !RSAHandler.Verify(publicKey, signaturePlain, signatureRSA))
{
throw new NetComSignatureException("*** The received packets signature is invalid! ***");
}
if (pServerClientList != null)
{
// Server -> Assign received data to clientlist
pServerClientList[pReceptionSocket].SetUserData(username, password, publicKey);
if (instruction != typeof(InstructionLibraryEssentials.KeyExchangeClient2Server).AssemblyQualifiedName &&
instruction != typeof(InstructionLibraryEssentials.ReceptionConfirmation).AssemblyQualifiedName &&
!pServerClientList[pReceptionSocket].Authenticate(password))
{
throw new NetComAuthenticationException("*** Authentication failed! Wrong username / password ***");
}
user = pServerClientList[pReceptionSocket];
}
else
{
// Client -> Ignore authentication-data
user = new NetComUser();
user.SetUserData(username, password, publicKey);
}
try
{
if (instruction == typeof(InstructionLibraryEssentials.ReceptionConfirmation).AssemblyQualifiedName)
{
retInstr.Add((InstructionBase)Activator.CreateInstance(Type.GetType(instruction), user, pLocalUser, value));
}
else if (value == null && parameters.Count == 0)
{
retInstr.Add((InstructionBase)Activator.CreateInstance(Type.GetType(instruction), user, pLocalUser));
}
else if (parameters.Count == 0)
{
retInstr.Add((InstructionBase)Activator.CreateInstance(Type.GetType(instruction), user, pLocalUser, value));
}
else
{
retInstr.Add((InstructionBase)Activator.CreateInstance(Type.GetType(instruction), user, pLocalUser, value, parameters.ToArray()));
}
// Increment the total receive counter
(pLocalUser as NetComOperator).TotalReceiveCounter++;
// Send confirmation (if the instruction is not a confirmation itself)
if (instruction != typeof(InstructionLibraryEssentials.ReceptionConfirmation).AssemblyQualifiedName)
{
(pLocalUser as NetComOperator).InstructionLogIncomming.Add(instructionID);
if (pLocalUser.GetType() == typeof(NetComClient))
{
(pLocalUser as NetComClient).Send(new InstructionLibraryEssentials.ReceptionConfirmation(pLocalUser, null, instructionID));
}
if (pLocalUser.GetType() == typeof(NetComServer))
{
(pLocalUser as NetComServer).Send(new InstructionLibraryEssentials.ReceptionConfirmation(pLocalUser, (pLocalUser as NetComServer).ConnectedClients[pReceptionSocket], instructionID));
}
}
}
catch (Exception ex)
{
(pLocalUser as NetComOperator).Debug("Could not recreate the instruction.", DebugType.Error);
if ((pLocalUser as NetComOperator).ShowExceptions)
{
(pLocalUser as NetComOperator).Debug($"({ex.GetType().Name}) {ex.Message}", DebugType.Exception);
}
}
}
}
return(retInstr.ToArray());
}
