private async Task DoAuthentication(IConnectionInfo connectionInfo)
{
Random r = new Random();
IPlainConnection connection = new PlainConnection(connectionInfo);
await connection.ConnectAsync();
TLReqPqMethod method = new TLReqPqMethod();
ReqPq reqPq = new ReqPq { Nonce = new byte[16] };
r.NextBytes(reqPq.Nonce);
TLFrame<ReqPq> frame = new TLFrame<ReqPq>
{
AuthKey = 0,
MessageId = DateTime.Now.ToUnixTime() * (Int64)Math.Pow(2, 32),
MessageLength = 20,
Content = reqPq
};
method.SendObject = frame;
TLFrame<ResPq> resPqFrame = await connection.ExecuteMethodAsync(method);
UInt64 pq = (UInt64)TLRootSerializer.Deserialize(resPqFrame.Content.Pq.Content.Reverse().ToList(), typeof(UInt64));
PqData pqData = _pqSolver.SolvePq(pq);
PqInnerData innerData = new PqInnerData
{
Nonce = resPqFrame.Content.Nonce,
ServerNonce = resPqFrame.Content.ServerNonce,
NewNonce = new byte[32],
Pq = resPqFrame.Content.Pq,
P = new TLBytes(TLRootSerializer.Serialize(pqData.P).Reverse().ToArray()),
Q = new TLBytes(TLRootSerializer.Serialize(pqData.Q).Reverse().ToArray())
};
r.NextBytes(innerData.NewNonce);
byte[] data = TLRootSerializer.Serialize(innerData);
UInt64 fingerprint = resPqFrame.Content.Vector.Content.First();
SHA1 shaAlgo = SHA1.Create();
byte[] sha1 = shaAlgo.ComputeHash(data);
List<byte> dataWithHash = sha1.Concat(data).ToList();
while (dataWithHash.Count < 255)
dataWithHash.Add((byte)(r.Next() & 0xFF));
byte[] encData = _rsaCrypter.EncryptBytes(dataWithHash.ToArray(), fingerprint);
TLFrame<ReqDhParams> reqDhFrame = new TLFrame<ReqDhParams>
{
AuthKey = 0,
MessageId = DateTime.Now.ToUnixTime() * (Int64)Math.Pow(2, 32),
MessageLength = 320,
Content = new ReqDhParams
{
Nonce = innerData.Nonce,
ServerNonce = innerData.ServerNonce,
P = innerData.P,
Q = innerData.Q,
Fingerprint = TLRootSerializer.Serialize(fingerprint),
EncryptedData = new TLBytes(encData)
}
};
TLReqDhParamsMethod reqDhMethod = new TLReqDhParamsMethod { SendObject = reqDhFrame };
TLFrame<ServerDhParams> dhParamsFrame = await connection.ExecuteMethodAsync(reqDhMethod);
ServerDhParamsOk paramsOk = dhParamsFrame.Content as ServerDhParamsOk;
if (paramsOk == null)
throw new ServerException("Didn't receive ServerDhParamsOk(0xd0e8075c)");
// SHA1(new_nonce + server_nonce)
byte[] tmpAesKey = shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.NewNonce, innerData.ServerNonce));
// + substr (SHA1(server_nonce + new_nonce), 0, 12)
tmpAesKey = tmpAesKey.Concat(shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.ServerNonce, innerData.NewNonce)).Take(12).ToArray()).ToArray();
// substr (SHA1(server_nonce + new_nonce), 12, 8)
byte[] tmpAesIv = shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.ServerNonce, innerData.NewNonce)).Skip(12).Take(8).ToArray();
// + SHA1(new_nonce + new_nonce)
tmpAesIv = tmpAesIv.Concat(shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.NewNonce, innerData.NewNonce))).ToArray();
// + substr (new_nonce, 0, 4);
tmpAesIv = tmpAesIv.Concat(innerData.NewNonce.Take(4)).ToArray();
byte[] decData = _aes256IgeCrypter.DecryptBytes(paramsOk.EncryptedAnswer.Content, tmpAesKey, tmpAesIv);
byte[] hash = decData.Take(20).ToArray();
decData = decData.Skip(20).ToArray();
ServerDhInnerData dhInnerData = TLRootSerializer.Deserialize<ServerDhInnerData>(decData.ToList());
if (!ArrayUtils.Equal(hash, shaAlgo.ComputeHash(TLRootSerializer.Serialize(dhInnerData))))
throw new SecurityException("SHA-1 hash not equal to ServerDhInnerData");
}
private async Task DoAuthenticationAsync(IConnectionInfo connectionInfo)
{
Random r = new Random();
IPlainConnection connection = new PlainConnection(connectionInfo);
await connection.ConnectAsync().ConfigureAwait(false);
TLReqPqMethod method = new TLReqPqMethod();
ReqPq reqPq = new ReqPq {
Nonce = new byte[16]
};
r.NextBytes(reqPq.Nonce);
TLFrame <ReqPq> frame = new TLFrame <ReqPq>
{
AuthKey = 0,
MessageId = DateTime.Now.ToUnixTime() * (Int64)Math.Pow(2, 32),
MessageLength = 20,
Content = reqPq
};
method.SendObject = frame;
TLFrame <ResPq> resPqFrame = await connection.ExecuteMethodAsync(method).ConfigureAwait(false);
UInt64 pq = (UInt64)TLRootSerializer.Deserialize(resPqFrame.Content.Pq.Content.Reverse().ToList(), typeof(UInt64));
PqData pqData = _pqSolver.SolvePq(pq);
PqInnerData innerData = new PqInnerData
{
Nonce = resPqFrame.Content.Nonce,
ServerNonce = resPqFrame.Content.ServerNonce,
NewNonce = new byte[32],
Pq = resPqFrame.Content.Pq,
P = new TLBytes(TLRootSerializer.Serialize(pqData.P).Reverse().ToArray()),
Q = new TLBytes(TLRootSerializer.Serialize(pqData.Q).Reverse().ToArray())
};
r.NextBytes(innerData.NewNonce);
byte[] data = TLRootSerializer.Serialize(innerData);
UInt64 fingerprint = resPqFrame.Content.Vector.Content.First();
SHA1 shaAlgo = SHA1.Create();
byte[] sha1 = shaAlgo.ComputeHash(data);
List <byte> dataWithHash = sha1.Concat(data).ToList();
while (dataWithHash.Count < 255)
{
dataWithHash.Add((byte)(r.Next() & 0xFF));
}
byte[] encData = _rsaCrypter.EncryptBytes(dataWithHash.ToArray(), fingerprint);
TLFrame <ReqDhParams> reqDhFrame = new TLFrame <ReqDhParams>
{
AuthKey = 0,
MessageId = DateTime.Now.ToUnixTime() * (Int64)Math.Pow(2, 32),
MessageLength = 320,
Content = new ReqDhParams
{
Nonce = innerData.Nonce,
ServerNonce = innerData.ServerNonce,
P = innerData.P,
Q = innerData.Q,
Fingerprint = TLRootSerializer.Serialize(fingerprint),
EncryptedData = new TLBytes(encData)
}
};
TLReqDhParamsMethod reqDhMethod = new TLReqDhParamsMethod {
SendObject = reqDhFrame
};
TLFrame <ServerDhParams> dhParamsFrame = await connection.ExecuteMethodAsync(reqDhMethod).ConfigureAwait(false);
ServerDhParamsOk paramsOk = dhParamsFrame.Content as ServerDhParamsOk;
if (paramsOk == null)
{
throw new ServerException("Didn't receive ServerDhParamsOk(0xd0e8075c)");
}
// SHA1(new_nonce + server_nonce)
byte[] tmpAesKey = shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.NewNonce, innerData.ServerNonce));
// + substr (SHA1(server_nonce + new_nonce), 0, 12)
tmpAesKey = tmpAesKey.Concat(shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.ServerNonce, innerData.NewNonce)).Take(12).ToArray()).ToArray();
// substr (SHA1(server_nonce + new_nonce), 12, 8)
byte[] tmpAesIv = shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.ServerNonce, innerData.NewNonce)).Skip(12).Take(8).ToArray();
// + SHA1(new_nonce + new_nonce)
tmpAesIv = tmpAesIv.Concat(shaAlgo.ComputeHash(ArrayUtils.Concat(innerData.NewNonce, innerData.NewNonce))).ToArray();
// + substr (new_nonce, 0, 4);
tmpAesIv = tmpAesIv.Concat(innerData.NewNonce.Take(4)).ToArray();
byte[] decData = _aes256IgeCrypter.DecryptBytes(paramsOk.EncryptedAnswer.Content, tmpAesKey, tmpAesIv);
byte[] hash = decData.Take(20).ToArray();
decData = decData.Skip(20).ToArray();
ServerDhInnerData dhInnerData = TLRootSerializer.Deserialize <ServerDhInnerData>(decData.ToList());
if (!ArrayUtils.Equal(hash, shaAlgo.ComputeHash(TLRootSerializer.Serialize(dhInnerData))))
{
throw new SecurityException("SHA-1 hash not equal to ServerDhInnerData");
}
}