private void ProcessAcceptedCall(TLPhoneCallAccepted phoneCallAccepted) { DispatchStateChanged(PhoneCallState.STATE_EXCHANGING_KEYS); if (!TLUtils.CheckGaAndGb(phoneCallAccepted.GB.Data, _secretP.Data)) { CallFailed(); return; } _authKey = MTProtoService.GetAuthKey(_aOrB, phoneCallAccepted.GB.ToBytes(), _secretP.ToBytes()); var keyHash = Utils.ComputeSHA1(_authKey); var keyFingerprint = new TLLong(BitConverter.ToInt64(keyHash, 12)); var peer = new TLInputPhoneCall { Id = phoneCallAccepted.Id, AccessHash = phoneCallAccepted.AccessHash }; var protocol = new TLPhoneCallProtocol { Flags = new TLInt(0), UdpP2P = true, UdpReflector = true, MinLayer = new TLInt(CALL_MIN_LAYER), MaxLayer = new TLInt(CALL_MAX_LAYER) }; _mtProtoService.ConfirmCallAsync(peer, TLString.FromBigEndianData(_ga), keyFingerprint, protocol, result => { _call = result; InitiateActualEncryptedCall(); }, error => { CallFailed(); }); }