We have acquired a 4 channel GSM Gateway, model GoIPx4-G610 (the manual is titled "GoIP Series SIM Card for GSM Voice Gateway - GSM VOIP Gateway").
We are looking to develop a custom application to control the GOIP gateway. We have developed in the past custom applications that controlled simple GSM modems through AT commands for sending/receiving SMS messages in particular.
Although the gateway can be controlled through SIP we would like to control the GSM modems embedded in the gateway through AT commands if possible. This is because of the fine grained control AT commands offer and because we do not need VoIP features since we need only to send/receive SMS messages.
The gateway runs an unknown Linux instance to which we can connect through telnet. Unfortunately we do not have the credentials to authenticate to it. The gateway also has a web http administration interface to which we can authenticate but we can't find there settings/information related to channels that we can use for AT commands.
The documentation is very poor and the provider could not offer us any helpful information regarding this.
If anyone knows how we can send AT commands to the modems inside the gateway it is highly appreciated.
Up to now we have tried a brute force attack on the telnet interface to find the credentials with no success. We hope that once we can connect to the Linux instance driving the gateway we can connect from there to the modems through serial connections (to send AT commands) and we can reconfigure it to redirect the connections outside of the modem or to make an interface for sending commands to the modems.
The device has an update firmware option (through the web interface) which always gives the error "download failed". Downloaded the firmware (.pkg file) manually from their update pages and extracted the files from the embedded Linux distribution that should correspond to the ones placed on the gateway. The files were kept in the pkg file as an ROMFS compressed image which we mounted on a test station to see the files (probably the running OS on the gateway is an uClinux distribution).
Did this hoping that we can find there the /etc/passwd file which could be cracked with classic attack. However didn't found it and probably that file is placed on the gateway flash memory (contrary to the Linux files which are stored on the ROM memory). So if there is a way to erase / reset this flash memory that could be a solution (in case the gateway doesn't refuse to boot without those files). Another solution would be to be able to access the flash memory with the passwd file if there is such thing.
You might take the lid off and see what parts are inside.
If it's a general purpose processor with a published data sheet and without a lot of code security features, you might be in luck. For example, you might find:
By guessing headers or tracing from known pins, a console serial port, either logic level or RS232, hopefully with a shell listening
A boot mode pin for the micro connected to a resistor, which you could jumper to cause the micro to boot to a uart bootloader where you could download a new system image, or patch the existing one. If you are lucky the bootloader would be something known, like u-boot.
A JTAG port for the processor
A removable storage device which you could remove and alter
an SPI flash which you could carefully tap into and alter
A flash chip which you could desolder and transplant to a programmer
You could also make a GPL sources request for the kernel and whatever else from the vendor. Or even just trying to identify versions of things like a web server could help you look up any known exploits. Since it seems you have a similar system image to that which is installed, looking through it could be helpful - look for additional daemons running, listening on ports you weren't previously aware of, left over debug support, etc.
I am the developer of the GoIP you've purchased. Instead of trying to hack the GoIP, did you contact us to support your development of custom applications? Here are the updates of GoIP for you.
GoIP now supports SMPP. This could be an alternative to using AT commands to send and receive SMS.
API (Application Programming Interface) for GoIP is now available to support your custom application development.
If AT commands are still the preferred method, please contact us and I would be happy to discuss with you further.
Related
I am supporting development of a client application that will be communicating to a seperate enterprise service bus. We have our own black box services to develop against. We each host multiple REST endpoints (using RESTeasy) to communicate.
One scenario we need to demonstrate to our client is sudden loss of network connectivity between my client application and their ESB with later network restoration. In the client demonstration, they plan to have separate workstations connected by a router and pull the cables for a few minutes and then reconnect them.
My question is that, while keeping both app running in eclipse on my workstation, can I temporarily block them from making successful REST requests to each other and then restore the connection? As best as possible to simulate the demonstration objective of pulling the network cables.
OS X El Capitan; Eclipse Neon; Jetty 9.2.7
Self Answer:
Not as elegant as I would like, but works because the endpoints are already compile-time configurable.
Add an entry to /etc/hosts for a volatile domain pointing to 127.0.0.1
127.0.0.1 volatileDomain
Configure my endpoints to point to volatileDomain.
Start both apps.
Edit and save /etc/hosts to comment out the volatileDomain line.
Watch disconnection logic handle the current state.
Edit and save /etc/hosts to reintroduce the volatileDomain line.
Watch reconnection logic reestablish the connected state.
I am looking for some clarification to how Google Smart Home works.
I am looking to integrate my current end device which control lights with Google Smart Home.
My end device is running a very small microcontroller utilizing an RTOS (Linux is not available)
Here is how I see it (Please correct or comment)
To my understanding this requires me to host my own cloud service
which will talk to my current end device?
My cloud service will then talk to Google cloud service.
My cloud service defines the protocol to talk to multiple end devices
Google Smart Home define the protocol to talk to my cloud service
Questions
Is there any method of doing this without having my own cloud Service?
That is a pretty basic summary of things - yes.
The crucial point there is that issuing a command to the Google Home does not have it send out a message on your local network. Google issues any commands from their network - not from your device.
This might seem like a minor detail, but it doesn't need to be a "cloud service" that you control that Google talks to. It does need to be a publicly accessible HTTPS endpoint. This could be a cloud service (and it would be in most cases), a public non-cloud server, or even just a public URL that has a tunnel to your private network (such as with ngrok).
The last is really how you'd get around having your own cloud service - you can setup the control on a local machine, and have a tunnel using ngrok.
I think a specific example may be beneficial: here's how to connect Google Home to your devices using an intermediary service like IFTTT:
Create a recipe (applet) on IFTTT to connect Google Assistant to an ngrok tunnel using the Webhook service. This permits you to define a simple keyword phrase that the Google Home will recognize (like "Hey Google turn on my device"). The applet will then call a webhook - e.g. ngrok - with a custom command that you get to define (like "https://myngroktunnel.ngrok.io/Control.cgi?mydevice=on" ), where myngroktunnel is your ngrok tunnel address (see below #2) and Control.cgi is the CGI script that you have placed on your microcontroller (see below #3).
You would need to install and run ngrok on your microcontroller: this will connect the IFTTT applet to your microcontroller via the ngrok tunnel and give you a publicly-accessible URL that forwards requests to your microcontroller. You would typically forward your ngrok tunnel to a specific port on your microcontroller where you are running a web server (e.g. Apache) with CGI scripts to control your device. There are other secure tunnel services available on the web: ngrok is just one of them. So, you do not have to host your own webservice, but you do have to use a tunnel to a publicly-accessible service.
The web server that you have placed on your microcontroller has CGI scripts that control your device (for example, let's say you have a Control.cgi script that turns your device on or off, given a command string like mydevice=on, e.g. the hook in the IFTTT applet is "/Control.cgi?mycommand=on"
Of course, the RTOS on your microcontroller muse be capable of running ngrok and a web server - this is why many people have chosen to use a single-board computer like the Raspberry Pi or Orange Pi running a form of linux to host and control their devices. Since your device's RTOS is not linux, I would suggest getting a linux device which would then forward the request to your RTOS device over your LAN.
I've been trying to configure a captive portal using DD-wrt and Open-wrt, with my own radius server and I've also tried to configure them using a CSP page (http://worldspot.net).
DD-wrt
My first try was with a TP-LINK WR841N (v7.) and DD-wrt using the web interface. In dd-wrt web interface there is an option in Services -> HotsPot -> ChilliSpot. Here I tried both configurations, using my own server data, and also tried with WorldSpot data, and my issue was the same in both cases:
When I enable Chillispot on the router, I don't get IP assigned, meaning I can't connect to the wifi/lan. It seems the problem is obviusly with the router and It's something like the Chillispot configuration is not working, or the changes are not"applied"
Open-wrt
After some hours trying to make work dd-wrt I think that maybe with open-wrt it was easier to configure, and here I found another problem. After updating my TP-LINK to Open-wrt I realized that I cannot access to the router via WEB, so I have to connect via telnet and ssh to install some packages and make some configurations.
I tried to install "luci" the package for the web gui and I found with some errors:
- First It didn't find the package, and I have to change the /etc/opkg.conf file
- Once I downloaded the package and try to access web I get error uci_load: not found
- Once I fixed the uci package issue, I enable the uhttpd and start it, but when I try to connect via web I get another error "CGI didn't receive any response"
Questions
Someone with more experience than me could point me wich of these softwares is better to have a spot system/captive portal ?
It's possible that in dd-wrt case the configuration of chillispot wasn't applied to the router configuration ?
For open-wrt anyone has same errors with the web interface ?
I've been reading and it seems that it's possible to configurate ChilliSpot via SSH , but the tutorials I found were not very helpfull, anyone can point me to a good tutorial for this ?
I also have a D-Link dir-615 H2 but it seems to be less compatible with open-wrt and dd-wrt than the TP-LINK.
I would be thankfull for any information that can put me in a good direction, thanks!
Some months ago I found a very easy answer for this question about making a captive portal.
The best of this solution is that the router flashing part is very automatized and the Captive Portal configuration is made through a WEB UI very easy to understand and manage
You may also connect through ssh to the router if some software customization is needed, like VLANS
To use this solution your modem should be in this list(At the time the answer is wrote):
Linksys: WRT54G | WRT54GL | WRT54GS
MiniRouter: MR3201A
FonSpot / Fonera (Atheros)
Ubiquiti: Bullet-M | Nano-M | Rocket-M | Airrouter | UniFi | Bullet/Nano/etc/{2/5}
I used this method in several Ubiquiti AirRouters and now it just take me 5 minutes to configure a router for a HotSpot system using FreeRadius.
I tried with FreeRadius installed in a RaspBerry in LAN and also into an VPS through WAN
The steps to flash any of the above routers are:
Download coova-ap.jnlp from here
Open the file with Java Web Start
For Linux systems: sudo javaws coova-ap.jnlp
You have to click Flash CoovaAP and you will see a window like this where you should select your router model:
After the file is downloaded you will see the next window:
Here you should select your network device, usually eth0 (wired) is the best choice, anyways I strongly recommend to click Save firmware to File button to store a backup of the original firmware.
If youre using an Ubiquiti router, before clicking the Start Flashing
you need to:
. If you re using a Ubiquiti device you should put it in TFTP mode by unplugging the POE ethernet cable, and reconnecting it while holding the reset button for 8 seconds. If this doesnt work, you may have to press it for 16 seconds. The LED lights now should flash alternately indicating TFTP mode.
Once you hit Start Flashing and the flash is done, the router will restart and we will be able to access the router using the same Coova software.
Now the Configure CoovaAP button should be clickable and we will see a very fancy interface to configure the router Captive Portal, we will be able to use different HotSpot configurations.
If the button is not clickable make sure the CoovaAP IP is 192.168.1.1
One of the guides that help me most to configure the router using CoovaAP software was HotSpotSystem: Installation CoovaAP guide
On that tutorial you will have more information about some steps and the mainly configuration of the Captive Portal interface. I didn't add the HotSpot part because the question was about which was the best router configuration.
There are some ways to build a captive portal server:
1.
Regarding router compatibility I can only recommend DD-WRT build 22118 or later (coovachilli based dd-wrt).
Following versions are supported: mini_hotspot (broadcom_K26 non-nv60k , non-nv64k!), nokaid, standard, big or mega. Other versions (like mini or micro) don’t contain the hotspot module so they cannot be used for hotspot purposes.
Once you have a such build, you can start a simple Captive Portal with Chillispot.
All what you need is a FreeRadius server & Web Server.
2.
Using OptWARE
Here I used a router Asus RT N16, I've patched it with dd-wrt.v24-18024_NEWD-2_K2.6_mega.bin
The entire tutorial is here.
I have a requirement to transfer/multicast a large file about >40g of file from a server to multiple clients at the same time and this will be done for only once. Is there any good protocol to do that in Linux? I tried using UFTP, but it didn't work.
UFTP should be a good tool for this situation. If the server and clients are on the same LAN, there shouldn't be any issue with them communicating. If there are one or more routers separating them, then you would either have to configure routers to allow multicast traffic to pass or you could use UFTP's proxy servers to create a bridge between different network segments.
You could use the excellent bittorrent protocol and make it private by using Bittorent Sync.
Go to Bittorrent Sync Web Site for details.
The main advantages I see are :
It's design to transport large files (if you have a network disruption it's not a problem)
It's free
It's cross plateform : Windows, Linux (i386, x64, ARM, PowerPC), FreeBSD, Mac, Android, IOS, and more ...
It's secure (you provide the encryption keys)
It's quite simple to configure
i have a problem with local network connection. i'm writing an iphone application and i need to read/write files to a computer. Both devices connected on the same network.
if it's possible, i want to get connected computers ip list, select one of them and read/write files like pdf, doc, txt etc.. if it's not possible to do, i will write the computer ip which i want to connect. There is no problem, both of solution is OK.
But i dont know what do i do after get the computer's ip ?
i found this chat client/server on local, but i got it very complicated.
Anyone have any idea about this ?
You'll need to have a server running on the computer, which can show files and allow for files to be read and created.
Easiest is to run a webdav service on the computer, Apache provides the mod_dav module for this purpose.
The iPhone app then becomes the client. I'd suggest using neon for this purpose. It's a C library that provides listing, reading and writing files on a remote webdav server.
That's how I would do it.
1) Find the network address of the computer you want to connect to. For this you can make use of Bonjour. It's very easy to setup because Bonjour handles the resolving of address for you.
You just have to publish a service (e.g. _myprotocol._tcp) via the ´NSNetService` class which is available on iOS and OS X (Windows too)- in your case you would publish the service on your computer.
Then you search for the service with the NSNetServiceBrowser class.
When you found a service you can then resolve it. This actually gives you the network name of the other device.
2) Connect to the other device via a tcp socket. The CocoaAsyncSocket library is very good at this. This project also includes some examples. One example already provides a bonjour server and client implementation.
i found exactly what i want. The solution is here