public void OnEvent(object source, OTREventArgs e)
{
switch (e.GetOTREvent())
{
case OTR_EVENT.MESSAGE:
break;
case OTR_EVENT.SEND:
break;
case OTR_EVENT.ERROR:
break;
case OTR_EVENT.READY:
break;
case OTR_EVENT.DEBUG:
break;
case OTR_EVENT.EXTRA_KEY_REQUEST:
break;
case OTR_EVENT.SMP_MESSAGE:
break;
case OTR_EVENT.CLOSED:
break;
}
}
private void OTRSessionEventHandler(object source, OTREventArgs e)
{
try
{
OnOTREvent(this, e);
if (/*e.GetOTREvent() == OTR_EVENT.ERROR ||*/ e.GetOTREvent() == OTR_EVENT.CLOSED)
{
DeleteOTRSession(e.GetSessionID());
}
}
catch
{
}
}
public void RequestOTRSession(string my_buddy_unique_id, string otr_version)
{
if (string.IsNullOrEmpty(otr_version) == true)
{
throw new ArgumentException("RequestOTRSession: The OTR version string cannot be null/empty");
}
if (IsSessionRegistered(my_buddy_unique_id) == false)
{
throw new ArgumentException("RequestOTRSession: my buddy unique id does not exist");
}
OTR_VERSION _otr_version = Utility.GetOTRVersion(otr_version);
if (_otr_version == OTR_VERSION.INVALID)
{
throw new ArgumentException("RequestOTRSession: OTR version is invalid");
}
string _otr_version_string = string.Empty;
if (_otr_version == OTR_VERSION.VERSION_2)
{
_otr_version_string = OTRConstants.OTR_VERSION_2;
}
else if (_otr_version == OTR_VERSION.VERSION_3)
{
_otr_version_string = OTRConstants.OTR_VERSION_3;
}
OTREventArgs _event_args = new OTREventArgs();
_event_args.SetMessage(_otr_version_string);
_event_args.SetOTREvent(OTR_EVENT.SEND);
_event_args.SetSessionID(my_buddy_unique_id);
OnOTREvent(this, _event_args);
}
private void OnAliceOTRMangerEventHandler(object source, OTREventArgs e)
{
switch (e.GetOTREvent())
{
case OTR_EVENT.MESSAGE:
log.Items.Add(String.Format("{0}: {1} \n", e.GetSessionID(), e.GetMessage()));
if (_alice_convo_pos < _alice_convo_array.Length)
{
_alice_convo_pos++;
_alice_otr_session_manager.EncryptMessage(_alice_my_buddy_unique_id, _alice_convo_array[_alice_convo_pos - 1]);
}
break;
case OTR_EVENT.SEND:
SendDataOnNetwork(_alice_unique_id, e.GetMessage());
break;
case OTR_EVENT.ERROR:
log.Items.Add(String.Format("Alice: OTR Error: {0} \n", e.GetErrorMessage()));
log.Items.Add(String.Format("Alice: OTR Error Verbose: {0} \n", e.GetErrorVerbose()));
break;
case OTR_EVENT.READY:
log.Items.Add(String.Format("Alice: Encrypted OTR session with {0} established \n", e.GetSessionID()));
_alice_convo_pos++;
_alice_otr_session_manager.EncryptMessage(_alice_my_buddy_unique_id, _alice_convo_array[_alice_convo_pos - 1]);
break;
case OTR_EVENT.DEBUG:
log.Items.Add(String.Format("Alice: " + e.GetMessage() + "\n"));
break;
case OTR_EVENT.EXTRA_KEY_REQUEST:
break;
case OTR_EVENT.SMP_MESSAGE:
log.Items.Add(String.Format("Alice: " + e.GetMessage() + "\n"));
break;
case OTR_EVENT.CLOSED:
log.Items.Add(String.Format("Alice: Encrypted OTR session with {0} closed \n", e.GetSessionID()));
break;
}
}
private void OTRSessionEventHandler(object source, OTREventArgs e)
{
try
{
OnOTREvent(this, e);
if (/*e.GetOTREvent() == OTR_EVENT.ERROR ||*/ e.GetOTREvent() == OTR_EVENT.CLOSED)
{
DeleteOTRSession(e.GetSessionID());
}
}
catch
{
}
}
private void SendError(string error_message)
{
error_message = OTRConstants.OTR_ERROR + error_message;
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage(error_message);
_otr_event_args.SetOTREvent(OTR_EVENT.SEND);
DoOTREvent(_otr_event_args);
}
private void OTRError(string error_string, string verbose_string, string remote_error_string)
{
if (string.IsNullOrEmpty(remote_error_string) == false)
SendError(remote_error_string);
if (string.IsNullOrEmpty(verbose_string) == true)
verbose_string = error_string;
_otr_event_args = new OTREventArgs();
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
_otr_event_args.SetErrorVerbose(verbose_string);
_otr_event_args.SetErrorMessage(error_string);
DoOTREvent(_otr_event_args);
// CloseOTRSession("Session closed as a result of OTR error");
}
public void RequestOTRSession(string my_buddy_unique_id, string otr_version)
{
if (string.IsNullOrEmpty(otr_version) == true)
throw new ArgumentException("RequestOTRSession: The OTR version string cannot be null/empty");
if (IsSessionRegistered(my_buddy_unique_id) == false)
throw new ArgumentException("RequestOTRSession: my buddy unique id does not exist");
OTR_VERSION _otr_version = Utility.GetOTRVersion(otr_version);
if (_otr_version == OTR_VERSION.INVALID)
throw new ArgumentException("RequestOTRSession: OTR version is invalid");
string _otr_version_string = string.Empty;
if (_otr_version == OTR_VERSION.VERSION_2)
_otr_version_string = OTRConstants.OTR_VERSION_2;
else if (_otr_version == OTR_VERSION.VERSION_3)
_otr_version_string = OTRConstants.OTR_VERSION_3;
OTREventArgs _event_args = new OTREventArgs();
_event_args.SetMessage(_otr_version_string);
_event_args.SetOTREvent(OTR_EVENT.SEND);
_event_args.SetSessionID(my_buddy_unique_id);
OnOTREvent(this, _event_args);
}
private void DebugPrint(string debug_text)
{
if (_debug_mode == false)
return;
_otr_event_args = new OTREventArgs();
_otr_event_args.SetOTREvent(OTR_EVENT.DEBUG);
_otr_event_args.SetMessage(debug_text);
DoOTREvent(_otr_event_args);
}
private void DoOTREvent(OTREventArgs event_args)
{
if (event_args == null)
return;
try
{
event_args.SetSessionID(_my_buddy_unique_id);
OnOTREvent(this, event_args);
}
catch
{
}
}
private void SendOTRMessage(byte[] message_data)
{
if (message_data == null || message_data.Length < 1)
throw new ArgumentException("SendOTRMessage: The message byte array to be sent cannot be null/empty");
try
{
_data_to_send = SetHeaderFooter(message_data);
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage(_data_to_send);
_otr_event_args.SetOTREvent(OTR_EVENT.SEND);
}
catch (Exception ex)
{
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
_otr_event_args.SetErrorVerbose("SendOTRMessage:" + ex.ToString());
_otr_event_args.SetErrorMessage("SendOTRMessage:Internal OTR error");
}
DoOTREvent(_otr_event_args);
}
private void CloseOTRSession(string session_closed_message)
{
DebugPrint("Ending OTR session");
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage(session_closed_message);
_otr_event_args.SetOTREvent(OTR_EVENT.CLOSED);
DoOTREvent(_otr_event_args);
_message_state = OTR_MESSAGE_STATE.MSG_STATE_PLAINTEXT;
_message_manager = null;
_ake_keys_manager = null;
_dsa_signer = null;
_signature_manager = null;
_smp_manager = null;
_ake_keys = null;
_my_unique_id = string.Empty;
_my_buddy_unique_id = string.Empty;
_otr_fragment_object = null;
EndSMPSession();
}
private void ProcessDHKeyMessage(OTRMessage otr_message)
{
DebugPrint("Received DH Key Message");
_otr_event_args = new OTREventArgs();
if (_authentication_state != OTR_AUTH_STATE.AUTH_STATE_AWAITING_DH_KEY)
{
OTRError("ProcessDHKeyMessage: OTR Engine is not in the AUTH_STATE_AWAITING_DH_KEY state", "ProcessDHKeyMessage: OTR Engine is not in the AUTH_STATE_AWAITING_DH_KEY state",
null);
return;
}
if (otr_message.GetGxMpi() == null || otr_message.GetGxMpi().Length < 1)
{
OTRError("ProcessDHKeyMessage: The received MPI encoded public key byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
if (_otr_session_object.IsSetBuddyFirstPublicKey(otr_message.GetGxMpi()) == false)
{
OTRError("ProcessDHKeyMessage:" + _my_buddy_unique_id + "'s DH public key is invalid",
"ProcessDHKeyMessage:" + _my_buddy_unique_id + "'s DH public key is invalid",
"OTR Failed. Unexpected error");
return;
}
_ake_keys = _ake_keys_manager.ComputeKeys(_otr_session_object.GetMyRecentDHKeyPair(), _otr_session_object.GetBuddyRecentPublicKey());
_signature_manager.ComputeSignature(_ake_keys, _otr_session_object.GetMyRecentDHKeyPair().GetPublicKeyMpiBytes(), _otr_session_object.GetMyRecentDHKeyPair().GetKeyIDBytes(),
otr_message.GetGxMpi(), _otr_session_object.GetCounter(), true);
if (_aes_key == null || _aes_key.Length < 1)
{
OTRError("ProcessDHKeyMessage: The AES key byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
Utility.EncodeOTRDataBE(_aes_key, ref _temp_buffer);
_temp_buffer_2 = new byte[_temp_buffer.Length + _signature_manager.GetSignatureDataLength()];
Buffer.BlockCopy(_temp_buffer, 0, _temp_buffer_2, 0, _temp_buffer.Length);
Buffer.BlockCopy(_signature_manager.GetSignatureDataBytes(), 0, _temp_buffer_2, _temp_buffer.Length, _signature_manager.GetSignatureDataLength());
byte[] _dh_reveal_byte_array = _message_manager.FormatRevealSig(_temp_buffer_2);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_AWAITING_SIG;
DebugPrint("Sending Reveal Signature Message");
SendOTRMessage(_dh_reveal_byte_array);
}
private void SendOTRFragement(string fragment_string, UInt16 fragment_number, UInt16 total_number_of_fragments)
{
if (string.IsNullOrEmpty(fragment_string) == true)
throw new ArgumentException("SendOTRFragement: The fragment string to be sent cannot be null/empty");
if (fragment_number > total_number_of_fragments)
throw new ArgumentException("SendOTRFragement: The fragment number cannot exceed the the total number of fragments");
try
{
_data_to_send = SetFragmentHeaderFooter(fragment_string, fragment_number, total_number_of_fragments);
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage(_data_to_send);
_otr_event_args.SetOTREvent(OTR_EVENT.SEND);
}
catch (Exception ex)
{
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
_otr_event_args.SetErrorVerbose("SendOTRFragement:" + ex.ToString());
_otr_event_args.SetErrorMessage("SendOTRFragement:Internal OTR error");
}
DoOTREvent(_otr_event_args);
}
private void ProcessTLVSMPMessage(byte[] smp_byte_data, OTR_TLV_TYPE tlv_type)
{
DebugPrint("Received SMP message with TLV of type " + tlv_type.ToString());
_smp_event_type_1 = OTR_SMP_EVENT.INVALID;
_smp_event_type_2 = OTR_SMP_EVENT.INVALID;
_smp_message = string.Empty;
StartSMPSession(false);
byte[] _message_byte_array = null;
byte[] _encoded_smp_bytes = _smp_manager.ProcessSMPMessage(smp_byte_data, tlv_type, ref _smp_event_type_1, ref _smp_event_type_2, ref _smp_message);
if (_smp_event_type_2 == OTR_SMP_EVENT.SUCCEEDED)
{
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage("SMP completed succesfully");
_otr_event_args.SetOTREvent(OTR_EVENT.SMP_MESSAGE);
_otr_event_args.SetSMPEvent(OTR_SMP_EVENT.SUCCEEDED);
DoOTREvent(_otr_event_args);
EndSMPSession();
}
if ((_smp_event_type_1 == OTR_SMP_EVENT.SEND) &&
(_encoded_smp_bytes != null && _encoded_smp_bytes.Length > 0))
{
_message_byte_array = FormatMessageWtTLV(null, _encoded_smp_bytes, null);
if (_smp_max_fragement_length > 0)
EncryptFragments(_message_byte_array, _smp_max_fragement_length);
else
EncryptMessage(_message_byte_array, false);
}
else if (_smp_event_type_1 == OTR_SMP_EVENT.ABORT)
{
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage(_smp_message);
_otr_event_args.SetOTREvent(OTR_EVENT.SMP_MESSAGE);
_otr_event_args.SetSMPEvent(OTR_SMP_EVENT.ABORT);
DoOTREvent(_otr_event_args);
EndSMPSession();
}
else if (_smp_event_type_1 == OTR_SMP_EVENT.FAILED)
{
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage("Man in the middle attack suspected");
_otr_event_args.SetOTREvent(OTR_EVENT.SMP_MESSAGE);
_otr_event_args.SetSMPEvent(OTR_SMP_EVENT.FAILED);
DoOTREvent(_otr_event_args);
EndSMPSession();
}
else if (_smp_event_type_1 == OTR_SMP_EVENT.SUCCEEDED)
{
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage("SMP completed succesfully");
_otr_event_args.SetOTREvent(OTR_EVENT.SMP_MESSAGE);
_otr_event_args.SetSMPEvent(OTR_SMP_EVENT.SUCCEEDED);
DoOTREvent(_otr_event_args);
EndSMPSession();
}
else
{
DebugPrint("ProcessTLVSMPMessage:Invalid SMP event");
EndSMPSession();
}
}
private void ProcessTLVSMPAbort(byte[] smp_abort_bytes)
{
DebugPrint("Abort SMP message was received from " + _my_buddy_unique_id);
_otr_event_args = new OTREventArgs();
_otr_event_args.SetMessage("SMP aborted based on request from " + _my_buddy_unique_id);
_otr_event_args.SetOTREvent(OTR_EVENT.SMP_MESSAGE);
_otr_event_args.SetSMPEvent(OTR_SMP_EVENT.ABORT);
DoOTREvent(_otr_event_args);
EndSMPSession();
}
private void ProcessSignatureMessage(OTRMessage otr_message)
{
DebugPrint("Received Signature Message");
_otr_event_args = new OTREventArgs();
if (_authentication_state != OTR_AUTH_STATE.AUTH_STATE_AWAITING_SIG)
{
OTRError("ProcessSignatureMessage: OTR Engine is not in the AUTH_STATE_AWAITING_SIG state",
"ProcessSignatureMessage: OTR Engine is not in the AUTH_STATE_AWAITING_SIG state",
null);
return;
}
if (otr_message.GetEncodedEncryptedSignature() == null || otr_message.GetEncodedEncryptedSignature().Length < 1)
{
OTRError("ProcessSignatureMessage: The encoded encrypted signature byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
if (otr_message.GetMacDSignature() == null || otr_message.GetMacDSignature().Length < 1)
{
OTRError("ProcessSignatureMessage: The MAC'd signature byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
byte[] dsa_public_key_byte_array_encoded = null;
bool _is_sig_verified = SignatureManager.IsSignatureVerified(_ake_keys, _otr_session_object.GetMyRecentDHKeyPair(), _otr_session_object.GetBuddyRecentPublicKeyMpi(),
otr_message.GetEncodedEncryptedSignature(), otr_message.GetMacDSignature(), false, ref _temp_int_32_val, ref dsa_public_key_byte_array_encoded);
if (_otr_session_object.IsComputeBuddyFingerPrint(dsa_public_key_byte_array_encoded) == false)
{
OTRError("ProcessSignatureMessage:" + _my_buddy_unique_id + "'s DSA public key fingerprint computation failed",
"ProcessSignatureMessage:" + _my_buddy_unique_id + "'s DSA public key fingerprint computation failed",
null);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
return;
}
if (_is_sig_verified != true)
{
OTRError("ProcessSignatureMessage:" + _my_buddy_unique_id + "'s signature verification failed",
"ProcessSignatureMessage:" + _my_buddy_unique_id + "'s signature verification failed",
null);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
return;
}
/* Inform client of OTR readiness */
_otr_session_object.SetFirstBuddyPublicKeyID(_temp_int_32_val);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
_message_state = OTR_MESSAGE_STATE.MSG_STATE_ENCRYPTED;
_otr_event_args.SetOTREvent(OTR_EVENT.READY);
_otr_event_args.SetMessage(_my_buddy_unique_id + "'s signature verification successful");
DoOTREvent(_otr_event_args);
}
private void ProcessRevealSigMessage(OTRMessage otr_message)
{
DebugPrint("Received Reveal Signature Message");
_otr_event_args = new OTREventArgs();
if (_authentication_state != OTR_AUTH_STATE.AUTH_STATE_AWAITING_REVEAL_SIG)
{
OTRError("ProcessRevealSigMessage: OTR Engine is not in the AUTH_STATE_AWAITING_REVEAL_SIG state",
"ProcessRevealSigMessage: OTR Engine is not in the AUTH_STATE_AWAITING_REVEAL_SIG state",
null);
return;
}
if (otr_message.GetRevealedKey() == null || otr_message.GetRevealedKey().Length < 1)
{
OTRError("ProcessRevealSigMessage: The AES revealed key byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
if (otr_message.GetEncodedEncryptedSignature() == null || otr_message.GetEncodedEncryptedSignature().Length < 1)
{
OTRError("ProcessRevealSigMessage: The encoded encrypted signature byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
if (otr_message.GetMacDSignature() == null || otr_message.GetMacDSignature().Length < 1)
{
OTRError("ProcessRevealSigMessage: The MAC'd signature byte array cannot be null/empty", null,
"OTR Failed. Unexpected error");
return;
}
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
if (_dh_commit_message == null || _dh_commit_message.GetEncryptedGxMpi() == null || _dh_commit_message.GetEncryptedGxMpi().Length < 1)
{
OTRError("ProcessRevealSigMessage: The MPI encoded encrypted public key (g^x mpi) should not be null/empty",
"ProcessRevealSigMessage: The MPI encoded encrypted public key (g^x mpi) should not be null/empty",
"OTR Failed. Unexpected error");
return;
}
if (_otr_session_object.IsSetMyBuddyFirstPublicKey(otr_message.GetRevealedKey(), _dh_commit_message.GetEncryptedGxMpi(),
_dh_commit_message.GetHashedGxMpi()) == false)
{
OTRError("ProcessRevealSigMessage: The MPI encoded decrypted public key (g^x mpi) should not be null/empty",
"ProcessRevealSigMessage: The MPI encoded decrypted public key (g^x mpi) should not be null/empty",
"OTR Failed. Unexpected error");
return;
}
_ake_keys = _ake_keys_manager.ComputeKeys(_otr_session_object.GetMyRecentDHKeyPair(), _otr_session_object.GetBuddyRecentPublicKey());
byte[] dsa_public_key_byte_array_encoded = null;
bool _is_sig_verified = SignatureManager.IsSignatureVerified(_ake_keys, _otr_session_object.GetMyRecentDHKeyPair(), _otr_session_object.GetBuddyRecentPublicKeyMpi(),
otr_message.GetEncodedEncryptedSignature(), otr_message.GetMacDSignature(), true, ref _temp_int_32_val, ref dsa_public_key_byte_array_encoded);
if (_otr_session_object.IsComputeBuddyFingerPrint(dsa_public_key_byte_array_encoded) == false)
{
OTRError("ProcessRevealSigMessage:" + _my_buddy_unique_id + "'s DSA public key fingerprint computation failed",
"ProcessRevealSigMessage:" + _my_buddy_unique_id + "'s DSA public key fingerprint computation failed",
null);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
return;
}
if (_is_sig_verified != true)
{
OTRError("ProcessRevealSigMessage:" + _my_buddy_unique_id + "'s signature verification failed",
"ProcessRevealSigMessage:" + _my_buddy_unique_id + "'s signature verification failed",
"OTR Failed. Unexpected error");
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
return;
}
_signature_manager.ComputeSignature(_ake_keys, _otr_session_object.GetMyRecentDHKeyPair().GetPublicKeyMpiBytes(), _otr_session_object.GetMyRecentDHKeyPair().GetKeyIDBytes(),
_otr_session_object.GetBuddyRecentPublicKeyMpi(), _otr_session_object.GetCounter(), false);
//Send signature message
byte[] _dh_signature_byte_array = _message_manager.FormatSignature(_signature_manager.GetSignatureDataBytes());
DebugPrint("Sending Signature Message");
SendOTRMessage(_dh_signature_byte_array);
/* Inform client of OTR readiness */
_otr_session_object.SetFirstBuddyPublicKeyID(_temp_int_32_val);
_authentication_state = OTR_AUTH_STATE.AUTH_STATE_NONE;
_message_state = OTR_MESSAGE_STATE.MSG_STATE_ENCRYPTED;
_otr_event_args.SetOTREvent(OTR_EVENT.READY);
_otr_event_args.SetMessage(_my_buddy_unique_id + "'s signature verification successful");
DoOTREvent(_otr_event_args);
}
private void ProcessOTRError(string otr_message_string)
{
string _temp_string = otr_message_string.Substring(0, 11);
_otr_event_args = new OTREventArgs();
_otr_event_args.SetOTREvent(OTR_EVENT.ERROR);
if (_temp_string.Equals(OTRConstants.OTR_ERROR) == false)
{
OTRError("ProcessOTRError: Received OTR message not properly formatted",
"ProcessOTRError: Received OTR message not properly formatted", null);
}
else
{
_temp_string = otr_message_string.Substring(11, otr_message_string.Length - 11);
if (!string.IsNullOrEmpty(_temp_string))
OTRError("ProcessOTRError: (Error Message from " + _my_buddy_unique_id + ") " + _temp_string,
"ProcessOTRError: (Error Message from " + _my_buddy_unique_id + ") " + _temp_string, null);
}
}