private byte[] ProcessSMPMessage3(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type_1, ref OTR.Interface.OTR_SMP_EVENT smp_event_type_2, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: The SMP byte array cannot be null/empty";
ResetData();
return(null);
}
if (_smp_state != OTR_SMP_STATE.EXPECT_3)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Illigal state";
ResetData();
return(null);
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_3_MPI_COUNT)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3:The MPI count must be " + MESSAGE_3_MPI_COUNT.ToString();
ResetData();
return(null);
}
byte[] _p_a_mpi = null;
byte[] _q_a_mpi = null;
byte[] _c_p_mpi = null;
byte[] _d_5_mpi = null;
byte[] _d_6_mpi = null;
byte[] _r_a_mpi = null;
byte[] _c_r_mpi = null;
byte[] _d_7_mpi = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _p_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _q_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_p_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_5_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_6_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _r_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_r_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_7_mpi);
_smp_third_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_p_a_mpi, 0, ref _smp_third_message_data[0]);
Utility.DecodeMpiFromBytes(_q_a_mpi, 0, ref _smp_third_message_data[1]);
Utility.DecodeMpiFromBytes(_c_p_mpi, 0, ref _smp_third_message_data[2]);
Utility.DecodeMpiFromBytes(_d_5_mpi, 0, ref _smp_third_message_data[3]);
Utility.DecodeMpiFromBytes(_d_6_mpi, 0, ref _smp_third_message_data[4]);
Utility.DecodeMpiFromBytes(_r_a_mpi, 0, ref _smp_third_message_data[5]);
Utility.DecodeMpiFromBytes(_c_r_mpi, 0, ref _smp_third_message_data[6]);
Utility.DecodeMpiFromBytes(_d_7_mpi, 0, ref _smp_third_message_data[7]);
if (IsValidValue(_smp_third_message_data[0]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Pa is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_third_message_data[1]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Qa is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_third_message_data[5]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Ra is not valid";
ResetData();
return(null);
}
if (VerifyZKProof(6, _smp_third_message_data[0], _smp_third_message_data[1],
_smp_third_message_data[2], _smp_third_message_data[3],
_smp_third_message_data[4]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Zero-Knowledge Proof (Prefix 6) failed";
ResetData();
return(null);
}
BigInteger _inverse = _session_object.Q.ModInverse(PRIME_MODULO);
_session_object.Qa_Qb = _smp_third_message_data[1].Multiply(_inverse).Mod(PRIME_MODULO);
_inverse = _session_object.P.ModInverse(PRIME_MODULO);
_session_object.Pa_Pb = _smp_third_message_data[0].Multiply(_inverse).Mod(PRIME_MODULO);
if (VerifyZKProofA(7, _smp_third_message_data[5],
_smp_third_message_data[6], _smp_third_message_data[7]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Zero-Knowledge Proof (Prefix 7) failed";
ResetData();
return(null);
}
BigInteger _r_ab = _smp_third_message_data[5].ModPow(_session_object.EXP_2, PRIME_MODULO);
_smp_state = OTR_SMP_STATE.EXPECT_1;
if (_r_ab.Equals(_session_object.Pa_Pb) == true)
{
smp_event_type_2 = OTR.Interface.OTR_SMP_EVENT.SUCCEEDED;
// Console.WriteLine("SMP completed succesfully \n");
message = "ProcessSMPMessage3: SMP completed succesfully";
ResetData();
}
else
{
smp_event_type_2 = OTR.Interface.OTR_SMP_EVENT.FAILED;
// Console.WriteLine("SMP Man in the middle suspected \n");
message = "ProcessSMPMessage3: SMP Man in the middle suspected";
ResetData();
}
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.SEND;
return(FormatSMPMessage4());
}
private byte[] ProcessSMPMessage1(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: The SMP byte array cannot be null/empty";
ResetData();
return(null);
}
if (_smp_state != OTR_SMP_STATE.EXPECT_1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Illigal state";
ResetData();
return(null);
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
byte[] _g_2_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_1_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: The MPI count must be " + MESSAGE_1_MPI_COUNT.ToString();
ResetData();
return(null);
}
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_3_mpi);
_smp_first_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_g_2_mpi, 0, ref _smp_first_message_data[0]);
Utility.DecodeMpiFromBytes(_c_2_mpi, 0, ref _smp_first_message_data[1]);
Utility.DecodeMpiFromBytes(_d_2_mpi, 0, ref _smp_first_message_data[2]);
Utility.DecodeMpiFromBytes(_g_3_mpi, 0, ref _smp_first_message_data[3]);
Utility.DecodeMpiFromBytes(_c_3_mpi, 0, ref _smp_first_message_data[4]);
Utility.DecodeMpiFromBytes(_d_3_mpi, 0, ref _smp_first_message_data[5]);
if (IsValidValue(_smp_first_message_data[0]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: G2a is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_first_message_data[3]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: G3a is not valid";
ResetData();
return(null);
}
if (VerifyZKProof(1, _smp_first_message_data[0], _smp_first_message_data[1], _smp_first_message_data[2]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Zero-Knowledge Proof (Prefix 1) failed";
ResetData();
return(null);
}
if (VerifyZKProof(2, _smp_first_message_data[3], _smp_first_message_data[4], _smp_first_message_data[5]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Zero-Knowledge Proof (Prefix 2) failed";
ResetData();
return(null);
}
_smp_state = OTR_SMP_STATE.EXPECT_3;
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SEND;
return(FormatSMPMessage2());
}
private byte[] ProcessSMPMessage2(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (_smp_state != OTR_SMP_STATE.EXPECT_2)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: The SMP byte array cannot be null/empty";
ResetData();
return(null);
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_2_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: The MPI count must be " + MESSAGE_2_MPI_COUNT.ToString();
ResetData();
return(null);
}
byte[] _g_2_b_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_b_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
byte[] _p_b_mpi = null;
byte[] _q_b_mpi = null;
byte[] _c_p_mpi = null;
byte[] _d_5_mpi = null;
byte[] _d_6_mpi = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_2_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_3_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _p_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _q_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_p_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_5_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_6_mpi);
_smp_second_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_g_2_b_mpi, 0, ref _smp_second_message_data[0]);
Utility.DecodeMpiFromBytes(_c_2_mpi, 0, ref _smp_second_message_data[1]);
Utility.DecodeMpiFromBytes(_d_2_mpi, 0, ref _smp_second_message_data[2]);
Utility.DecodeMpiFromBytes(_g_3_b_mpi, 0, ref _smp_second_message_data[3]);
Utility.DecodeMpiFromBytes(_c_3_mpi, 0, ref _smp_second_message_data[4]);
Utility.DecodeMpiFromBytes(_d_3_mpi, 0, ref _smp_second_message_data[5]);
Utility.DecodeMpiFromBytes(_p_b_mpi, 0, ref _smp_second_message_data[6]);
Utility.DecodeMpiFromBytes(_q_b_mpi, 0, ref _smp_second_message_data[7]);
Utility.DecodeMpiFromBytes(_c_p_mpi, 0, ref _smp_second_message_data[8]);
Utility.DecodeMpiFromBytes(_d_5_mpi, 0, ref _smp_second_message_data[9]);
Utility.DecodeMpiFromBytes(_d_6_mpi, 0, ref _smp_second_message_data[10]);
if (IsValidValue(_smp_second_message_data[0]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: G2b is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_second_message_data[3]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: G3b is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_second_message_data[6]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: P is not valid";
ResetData();
return(null);
}
if (IsValidValue(_smp_second_message_data[7]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Q is not valid";
ResetData();
return(null);
}
_session_object.G_2 = _smp_second_message_data[0].ModPow(_session_object.EXP_1, PRIME_MODULO);
_session_object.G_3 = _smp_second_message_data[3].ModPow(_session_object.EXP_2, PRIME_MODULO);
if (VerifyZKProof(3, _smp_second_message_data[0], _smp_second_message_data[1], _smp_second_message_data[2]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 3) failed";
ResetData();
return(null);
}
if (VerifyZKProof(4, _smp_second_message_data[3], _smp_second_message_data[4], _smp_second_message_data[5]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 4) failed";
ResetData();
return(null);
}
if (VerifyZKProof(5, _smp_second_message_data[6], _smp_second_message_data[7],
_smp_second_message_data[8], _smp_second_message_data[9],
_smp_second_message_data[10]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 5) failed";
ResetData();
return(null);
}
_smp_state = OTR_SMP_STATE.EXPECT_4;
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SEND;
return(FormatSMPMessage3());
}
private void ResetData()
{
_smp_state = OTR_SMP_STATE.EXPECT_1;
_is_started = false;
}
public byte[] FormatSMPMessage1()
{
SetFirstMessageData();
if (_smp_first_message_data == null || _smp_first_message_data.Length < MESSAGE_1_MPI_COUNT)
{
throw new InvalidDataException("FormatSMPMessage1:The SMP first message data cannot be null or have elements less than " + MESSAGE_1_MPI_COUNT.ToString());
}
byte[] _temp_mpi_buff = null;
byte[] _message_buff = null;
byte[] _g_2_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
int _buff_length = 0;
int _next_index = 0;
Utility.EncodeMpiBytes(_smp_first_message_data[0], ref _g_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[1], ref _c_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[2], ref _d_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[3], ref _g_3_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[4], ref _c_3_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[5], ref _d_3_mpi);
_buff_length = _g_2_mpi.Length + _c_2_mpi.Length + _d_2_mpi.Length;
_buff_length += _g_3_mpi.Length + _c_3_mpi.Length + _d_3_mpi.Length;
_temp_mpi_buff = new byte[_buff_length];
Buffer.BlockCopy(_g_2_mpi, 0, _temp_mpi_buff, _next_index, _g_2_mpi.Length);
_next_index += _g_2_mpi.Length;
Buffer.BlockCopy(_c_2_mpi, 0, _temp_mpi_buff, _next_index, _c_2_mpi.Length);
_next_index += _c_2_mpi.Length;
Buffer.BlockCopy(_d_2_mpi, 0, _temp_mpi_buff, _next_index, _d_2_mpi.Length);
_next_index += _d_2_mpi.Length;
Buffer.BlockCopy(_g_3_mpi, 0, _temp_mpi_buff, _next_index, _g_3_mpi.Length);
_next_index += _g_3_mpi.Length;
Buffer.BlockCopy(_c_3_mpi, 0, _temp_mpi_buff, _next_index, _c_3_mpi.Length);
_next_index += _c_3_mpi.Length;
Buffer.BlockCopy(_d_3_mpi, 0, _temp_mpi_buff, _next_index, _d_3_mpi.Length);
_next_index += _d_3_mpi.Length;
Utility.EncodeTLVSMPMessage(OTR_TLV_TYPE.SMP_MESSAGE_1, MESSAGE_1_MPI_COUNT, _temp_mpi_buff, ref _message_buff);
_smp_state = OTR_SMP_STATE.EXPECT_2;
return(_message_buff);
}
private void ResetData()
{
_smp_state = OTR_SMP_STATE.EXPECT_1;
_is_started = false;
}
private byte[] ProcessSMPMessage4(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: The SMP byte array cannot be null/empty";
ResetData();
return(null);
}
if (_smp_state != OTR_SMP_STATE.EXPECT_4)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Illigal state";
ResetData();
return(null);
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_4_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: The MPI count must be " + MESSAGE_4_MPI_COUNT.ToString();
ResetData();
return(null);
}
byte[] _r_b_mpi = null;
byte[] _c_mpi = null;
byte[] _d_mpi = null;
BigInteger _r_b = null;
BigInteger _c = null;
BigInteger _d = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _r_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_mpi);
Utility.DecodeMpiFromBytes(_r_b_mpi, 0, ref _r_b);
Utility.DecodeMpiFromBytes(_c_mpi, 0, ref _c);
Utility.DecodeMpiFromBytes(_d_mpi, 0, ref _d);
if (IsValidValue(_r_b) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Rb is not valid";
ResetData();
return(null);
}
if (VerifyZKProofA(8, _r_b, _c, _d) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Zero-Knowledge Proof (Prefix 8) failed";
ResetData();
return(null);
}
_smp_state = OTR_SMP_STATE.EXPECT_1;
BigInteger _r_ab = _r_b.ModPow(_session_object.EXP_2, PRIME_MODULO);
if (_r_ab.Equals(_session_object.Pa_Pb) == true)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SUCCEEDED;
// Console.WriteLine("SMP completed succesfully \n");
message = "ProcessSMPMessage4: SMP completed succesfully";
ResetData();
}
else
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.FAILED;
// Console.WriteLine("SMP Man in the middle suspected \n");
message = "ProcessSMPMessage4: SMP Man in the middle suspected";
ResetData();
}
return(null);
}
private byte[] ProcessSMPMessage4(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: The SMP byte array cannot be null/empty";
ResetData();
return null;
}
if (_smp_state != OTR_SMP_STATE.EXPECT_4)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Illigal state";
ResetData();
return null;
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_4_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: The MPI count must be " + MESSAGE_4_MPI_COUNT.ToString();
ResetData();
return null;
}
byte[] _r_b_mpi = null;
byte[] _c_mpi = null;
byte[] _d_mpi = null;
BigInteger _r_b = null;
BigInteger _c = null;
BigInteger _d = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _r_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_mpi);
Utility.DecodeMpiFromBytes(_r_b_mpi, 0, ref _r_b);
Utility.DecodeMpiFromBytes(_c_mpi, 0, ref _c);
Utility.DecodeMpiFromBytes(_d_mpi, 0, ref _d);
if (IsValidValue(_r_b) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Rb is not valid";
ResetData();
return null;
}
if (VerifyZKProofA(8, _r_b,_c, _d) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage4: Zero-Knowledge Proof (Prefix 8) failed";
ResetData();
return null;
}
_smp_state = OTR_SMP_STATE.EXPECT_1;
BigInteger _r_ab = _r_b.ModPow(_session_object.EXP_2, PRIME_MODULO);
if (_r_ab.Equals(_session_object.Pa_Pb) == true)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SUCCEEDED;
// Console.WriteLine("SMP completed succesfully \n");
message = "ProcessSMPMessage4: SMP completed succesfully";
ResetData();
}
else
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.FAILED;
// Console.WriteLine("SMP Man in the middle suspected \n");
message = "ProcessSMPMessage4: SMP Man in the middle suspected";
ResetData();
}
return null;
}
public byte[] FormatSMPMessage1()
{
SetFirstMessageData();
if (_smp_first_message_data == null || _smp_first_message_data.Length < MESSAGE_1_MPI_COUNT)
throw new InvalidDataException("FormatSMPMessage1:The SMP first message data cannot be null or have elements less than " + MESSAGE_1_MPI_COUNT.ToString());
byte[] _temp_mpi_buff = null;
byte[] _message_buff = null;
byte[] _g_2_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
int _buff_length = 0;
int _next_index = 0;
Utility.EncodeMpiBytes(_smp_first_message_data[0], ref _g_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[1], ref _c_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[2], ref _d_2_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[3], ref _g_3_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[4], ref _c_3_mpi);
Utility.EncodeMpiBytes(_smp_first_message_data[5], ref _d_3_mpi);
_buff_length = _g_2_mpi.Length + _c_2_mpi.Length + _d_2_mpi.Length;
_buff_length += _g_3_mpi.Length + _c_3_mpi.Length + _d_3_mpi.Length;
_temp_mpi_buff = new byte[_buff_length];
Buffer.BlockCopy(_g_2_mpi, 0, _temp_mpi_buff, _next_index, _g_2_mpi.Length);
_next_index += _g_2_mpi.Length;
Buffer.BlockCopy(_c_2_mpi, 0, _temp_mpi_buff, _next_index, _c_2_mpi.Length);
_next_index += _c_2_mpi.Length;
Buffer.BlockCopy(_d_2_mpi, 0, _temp_mpi_buff, _next_index, _d_2_mpi.Length);
_next_index += _d_2_mpi.Length;
Buffer.BlockCopy(_g_3_mpi, 0, _temp_mpi_buff, _next_index, _g_3_mpi.Length);
_next_index += _g_3_mpi.Length;
Buffer.BlockCopy(_c_3_mpi, 0, _temp_mpi_buff, _next_index, _c_3_mpi.Length);
_next_index += _c_3_mpi.Length;
Buffer.BlockCopy(_d_3_mpi, 0, _temp_mpi_buff, _next_index, _d_3_mpi.Length);
_next_index += _d_3_mpi.Length;
Utility.EncodeTLVSMPMessage(OTR_TLV_TYPE.SMP_MESSAGE_1, MESSAGE_1_MPI_COUNT, _temp_mpi_buff, ref _message_buff);
_smp_state = OTR_SMP_STATE.EXPECT_2;
return _message_buff;
}
private byte[] ProcessSMPMessage3(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type_1, ref OTR.Interface.OTR_SMP_EVENT smp_event_type_2, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: The SMP byte array cannot be null/empty";
ResetData();
return null;
}
if (_smp_state != OTR_SMP_STATE.EXPECT_3)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Illigal state";
ResetData();
return null;
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_3_MPI_COUNT)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3:The MPI count must be " + MESSAGE_3_MPI_COUNT.ToString();
ResetData();
return null;
}
byte[] _p_a_mpi = null;
byte[] _q_a_mpi = null;
byte[] _c_p_mpi = null;
byte[] _d_5_mpi = null;
byte[] _d_6_mpi = null;
byte[] _r_a_mpi = null;
byte[] _c_r_mpi = null;
byte[] _d_7_mpi = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _p_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _q_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_p_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_5_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_6_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _r_a_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_r_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_7_mpi);
_smp_third_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_p_a_mpi, 0, ref _smp_third_message_data[0]);
Utility.DecodeMpiFromBytes(_q_a_mpi, 0, ref _smp_third_message_data[1]);
Utility.DecodeMpiFromBytes(_c_p_mpi, 0, ref _smp_third_message_data[2]);
Utility.DecodeMpiFromBytes(_d_5_mpi, 0, ref _smp_third_message_data[3]);
Utility.DecodeMpiFromBytes(_d_6_mpi, 0, ref _smp_third_message_data[4]);
Utility.DecodeMpiFromBytes(_r_a_mpi, 0, ref _smp_third_message_data[5]);
Utility.DecodeMpiFromBytes(_c_r_mpi, 0, ref _smp_third_message_data[6]);
Utility.DecodeMpiFromBytes(_d_7_mpi, 0, ref _smp_third_message_data[7]);
if (IsValidValue(_smp_third_message_data[0]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Pa is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_third_message_data[1]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Qa is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_third_message_data[5]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Ra is not valid";
ResetData();
return null;
}
if (VerifyZKProof(6, _smp_third_message_data[0], _smp_third_message_data[1],
_smp_third_message_data[2], _smp_third_message_data[3],
_smp_third_message_data[4]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Zero-Knowledge Proof (Prefix 6) failed";
ResetData();
return null;
}
BigInteger _inverse = _session_object.Q.ModInverse(PRIME_MODULO);
_session_object.Qa_Qb = _smp_third_message_data[1].Multiply(_inverse).Mod(PRIME_MODULO);
_inverse = _session_object.P.ModInverse(PRIME_MODULO);
_session_object.Pa_Pb = _smp_third_message_data[0].Multiply(_inverse).Mod(PRIME_MODULO);
if (VerifyZKProofA(7,_smp_third_message_data[5],
_smp_third_message_data[6], _smp_third_message_data[7]) == false)
{
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: Zero-Knowledge Proof (Prefix 7) failed";
ResetData();
return null;
}
BigInteger _r_ab = _smp_third_message_data[5].ModPow(_session_object.EXP_2, PRIME_MODULO);
_smp_state = OTR_SMP_STATE.EXPECT_1;
if (_r_ab.Equals(_session_object.Pa_Pb) == true)
{
smp_event_type_2 = OTR.Interface.OTR_SMP_EVENT.SUCCEEDED;
// Console.WriteLine("SMP completed succesfully \n");
message = "ProcessSMPMessage3: SMP completed succesfully";
ResetData();
}
else
{
smp_event_type_2 = OTR.Interface.OTR_SMP_EVENT.FAILED;
// Console.WriteLine("SMP Man in the middle suspected \n");
message = "ProcessSMPMessage3: SMP Man in the middle suspected";
ResetData();
}
smp_event_type_1 = OTR.Interface.OTR_SMP_EVENT.SEND;
return FormatSMPMessage4();
}
private byte[] ProcessSMPMessage2(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (_smp_state != OTR_SMP_STATE.EXPECT_2)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: The SMP byte array cannot be null/empty";
ResetData();
return null;
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_2_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: The MPI count must be " + MESSAGE_2_MPI_COUNT.ToString();
ResetData();
return null;
}
byte[] _g_2_b_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_b_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
byte[] _p_b_mpi = null;
byte[] _q_b_mpi = null;
byte[] _c_p_mpi = null;
byte[] _d_5_mpi = null;
byte[] _d_6_mpi = null;
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_2_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_3_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _p_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _q_b_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_p_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_5_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_6_mpi);
_smp_second_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_g_2_b_mpi, 0, ref _smp_second_message_data[0]);
Utility.DecodeMpiFromBytes(_c_2_mpi, 0, ref _smp_second_message_data[1]);
Utility.DecodeMpiFromBytes(_d_2_mpi, 0, ref _smp_second_message_data[2]);
Utility.DecodeMpiFromBytes(_g_3_b_mpi, 0, ref _smp_second_message_data[3]);
Utility.DecodeMpiFromBytes(_c_3_mpi, 0, ref _smp_second_message_data[4]);
Utility.DecodeMpiFromBytes(_d_3_mpi, 0, ref _smp_second_message_data[5]);
Utility.DecodeMpiFromBytes(_p_b_mpi, 0, ref _smp_second_message_data[6]);
Utility.DecodeMpiFromBytes(_q_b_mpi, 0, ref _smp_second_message_data[7]);
Utility.DecodeMpiFromBytes(_c_p_mpi, 0, ref _smp_second_message_data[8]);
Utility.DecodeMpiFromBytes(_d_5_mpi, 0, ref _smp_second_message_data[9]);
Utility.DecodeMpiFromBytes(_d_6_mpi, 0, ref _smp_second_message_data[10]);
if (IsValidValue(_smp_second_message_data[0]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: G2b is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_second_message_data[3]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: G3b is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_second_message_data[6]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: P is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_second_message_data[7]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Q is not valid";
ResetData();
return null;
}
_session_object.G_2 = _smp_second_message_data[0].ModPow(_session_object.EXP_1, PRIME_MODULO);
_session_object.G_3 = _smp_second_message_data[3].ModPow(_session_object.EXP_2, PRIME_MODULO);
if (VerifyZKProof(3, _smp_second_message_data[0], _smp_second_message_data[1], _smp_second_message_data[2]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 3) failed";
ResetData();
return null;
}
if (VerifyZKProof(4, _smp_second_message_data[3], _smp_second_message_data[4], _smp_second_message_data[5]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 4) failed";
ResetData();
return null;
}
if (VerifyZKProof(5, _smp_second_message_data[6], _smp_second_message_data[7],
_smp_second_message_data[8], _smp_second_message_data[9],
_smp_second_message_data[10]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage2: Zero-Knowledge Proof (Prefix 5) failed";
ResetData();
return null;
}
_smp_state = OTR_SMP_STATE.EXPECT_4;
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SEND;
return FormatSMPMessage3();
}
private byte[] ProcessSMPMessage1(byte[] smp_byte_array, ref OTR.Interface.OTR_SMP_EVENT smp_event_type, ref string message)
{
if (smp_byte_array == null || smp_byte_array.Length < 1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: The SMP byte array cannot be null/empty";
ResetData();
return null;
}
if (_smp_state != OTR_SMP_STATE.EXPECT_1)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Illigal state";
ResetData();
return null;
}
int _start_index = 0;
uint _mpi_count = 0;
byte[] _mpis_buffer = null;
byte[] _g_2_mpi = null;
byte[] _c_2_mpi = null;
byte[] _d_2_mpi = null;
byte[] _g_3_mpi = null;
byte[] _c_3_mpi = null;
byte[] _d_3_mpi = null;
Utility.DecodeTLVSMPMessage(smp_byte_array, _start_index, ref _mpi_count, ref _mpis_buffer);
if (_mpi_count != MESSAGE_1_MPI_COUNT)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: The MPI count must be " + MESSAGE_1_MPI_COUNT.ToString();
ResetData();
return null;
}
_start_index = 0;
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_2_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _g_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _c_3_mpi);
_start_index = Utility.DecoupleMpiFromBytes(_mpis_buffer, _start_index, ref _d_3_mpi);
_smp_first_message_data = new BigInteger[_mpi_count];
Utility.DecodeMpiFromBytes(_g_2_mpi, 0, ref _smp_first_message_data[0]);
Utility.DecodeMpiFromBytes(_c_2_mpi, 0, ref _smp_first_message_data[1]);
Utility.DecodeMpiFromBytes(_d_2_mpi, 0, ref _smp_first_message_data[2]);
Utility.DecodeMpiFromBytes(_g_3_mpi, 0, ref _smp_first_message_data[3]);
Utility.DecodeMpiFromBytes(_c_3_mpi, 0, ref _smp_first_message_data[4]);
Utility.DecodeMpiFromBytes(_d_3_mpi, 0, ref _smp_first_message_data[5]);
if (IsValidValue(_smp_first_message_data[0]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: G2a is not valid";
ResetData();
return null;
}
if (IsValidValue(_smp_first_message_data[3]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage3: G3a is not valid";
ResetData();
return null;
}
if (VerifyZKProof(1, _smp_first_message_data[0], _smp_first_message_data[1], _smp_first_message_data[2]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Zero-Knowledge Proof (Prefix 1) failed";
ResetData();
return null;
}
if (VerifyZKProof(2, _smp_first_message_data[3], _smp_first_message_data[4], _smp_first_message_data[5]) == false)
{
smp_event_type = OTR.Interface.OTR_SMP_EVENT.ABORT;
message = "ProcessSMPMessage1: Zero-Knowledge Proof (Prefix 2) failed";
ResetData();
return null;
}
_smp_state = OTR_SMP_STATE.EXPECT_3;
smp_event_type = OTR.Interface.OTR_SMP_EVENT.SEND;
return FormatSMPMessage2();
}
